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acrac_69358_0 | Osteoporosis and Bone Mineral Density | Introduction/Background Osteoporosis is a systemic skeletal condition characterized by reduced bone density and deterioration of osseous tissue that leads to bone fragility and increased susceptibility to fracture [1]. Bone strength is a product of bone mineral density (BMD), a quantifiable property, and the integrity of trabecular microarchitecture. Currently, the consensus approach to screening and monitoring osteoporosis in the population is measurement of BMD, which is an effective way to identify patients who are at risk for fracture. An estimated 10.2 million adults in the United States >50 years of age have osteoporosis; however, the aging of the population is projected to increase this number by >30% by 2030, even though most experts agree that osteoporosis is generally underdiagnosed [2,3]. Approximately one-half of women and nearly one-third of men >50 years of age will sustain an osteoporotic fracture [4]. The yearly number of fractures is projected to increase from 1.9 million in 2018 to over 3.2 million fractures by 2040, with direct medical costs increasing from $48.8 billion to $81.5 billion during the same time range [5,6]. When indirect societal costs are also considered, the total projected cost could exceed $95 billion by 2040 [6]. Osteoporotic fractures are associated with subsequent fractures and premature mortality. In patients who have sustained a fracture, 10% will have another within 1 year, 18% within 2 years, and 31% within 5 years [7]. The first-year mortality rate is 20%, but there is also a 3- to 4-fold increased risk of mortality in the subsequent 5 years following any fragility fracture [8]. It is highest after sustaining a hip fracture, where there is a 1-year mortality of 24% in women and 38% in men [9]. Fragility fractures are also associated with a decrease in quality of life, diminished physical function, and reduced independence [10]. | Osteoporosis and Bone Mineral Density. Introduction/Background Osteoporosis is a systemic skeletal condition characterized by reduced bone density and deterioration of osseous tissue that leads to bone fragility and increased susceptibility to fracture [1]. Bone strength is a product of bone mineral density (BMD), a quantifiable property, and the integrity of trabecular microarchitecture. Currently, the consensus approach to screening and monitoring osteoporosis in the population is measurement of BMD, which is an effective way to identify patients who are at risk for fracture. An estimated 10.2 million adults in the United States >50 years of age have osteoporosis; however, the aging of the population is projected to increase this number by >30% by 2030, even though most experts agree that osteoporosis is generally underdiagnosed [2,3]. Approximately one-half of women and nearly one-third of men >50 years of age will sustain an osteoporotic fracture [4]. The yearly number of fractures is projected to increase from 1.9 million in 2018 to over 3.2 million fractures by 2040, with direct medical costs increasing from $48.8 billion to $81.5 billion during the same time range [5,6]. When indirect societal costs are also considered, the total projected cost could exceed $95 billion by 2040 [6]. Osteoporotic fractures are associated with subsequent fractures and premature mortality. In patients who have sustained a fracture, 10% will have another within 1 year, 18% within 2 years, and 31% within 5 years [7]. The first-year mortality rate is 20%, but there is also a 3- to 4-fold increased risk of mortality in the subsequent 5 years following any fragility fracture [8]. It is highest after sustaining a hip fracture, where there is a 1-year mortality of 24% in women and 38% in men [9]. Fragility fractures are also associated with a decrease in quality of life, diminished physical function, and reduced independence [10]. | 69358 |
acrac_69358_1 | Osteoporosis and Bone Mineral Density | Given the proven efficacy of pharmacologic therapy, the role of imaging to appropriately identify and monitor high-risk individuals is critical in substantially reducing osteoporosis-associated morbidity and mortality. Special Imaging Considerations Dual-energy X-ray absorptiometry (DXA) is the mainstay of bone densitometry to screen for osteopenia and osteoporosis. Because this modality relies on precision, it is essential for patients to be scanned on the same DXA machine because differences in vendor technologies prohibit a direct comparison unless cross calibration has been performed [11,12]. CT is a cross-sectional-based X-ray technology that uses tomographic technique coupled with computer processing to generate a cross-sectional image. CT has a higher sensitivity to subtle differences in electron densities than radiography and therefore creates an image with markedly improved contrast. Quantitative CT (QCT) is performed on a standard clinical scanner and is highly accurate in determining tissue density within a region of interest. Scanning sites for QCT include the lumbar spine and hip. Several studies have assessed using conventional CT scans for measurement of bone density by establishing threshold Hounsfield unit levels that are diagnostic for osteopenia and osteoporosis, but this concept remains an opportunistic use of CT and not a screening tool [13-15]. High-resolution peripheral QCT uses the same technology in a smaller dedicated machine and focuses on the distal radius and tibia. Currently, peripheral QCT studies are not approved for diagnosis aThe Ohio State University Wexner Medical Center, Columbus, Ohio. bResearch Author, Ohio State University, Columbus, Ohio. cPanel Chair, Mayo Clinic Arizona, Phoenix, Arizona. dUniversity of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. eMayo Clinic, Rochester, Minnesota. fHospital for Special Surgery, New York, New York. | Osteoporosis and Bone Mineral Density. Given the proven efficacy of pharmacologic therapy, the role of imaging to appropriately identify and monitor high-risk individuals is critical in substantially reducing osteoporosis-associated morbidity and mortality. Special Imaging Considerations Dual-energy X-ray absorptiometry (DXA) is the mainstay of bone densitometry to screen for osteopenia and osteoporosis. Because this modality relies on precision, it is essential for patients to be scanned on the same DXA machine because differences in vendor technologies prohibit a direct comparison unless cross calibration has been performed [11,12]. CT is a cross-sectional-based X-ray technology that uses tomographic technique coupled with computer processing to generate a cross-sectional image. CT has a higher sensitivity to subtle differences in electron densities than radiography and therefore creates an image with markedly improved contrast. Quantitative CT (QCT) is performed on a standard clinical scanner and is highly accurate in determining tissue density within a region of interest. Scanning sites for QCT include the lumbar spine and hip. Several studies have assessed using conventional CT scans for measurement of bone density by establishing threshold Hounsfield unit levels that are diagnostic for osteopenia and osteoporosis, but this concept remains an opportunistic use of CT and not a screening tool [13-15]. High-resolution peripheral QCT uses the same technology in a smaller dedicated machine and focuses on the distal radius and tibia. Currently, peripheral QCT studies are not approved for diagnosis aThe Ohio State University Wexner Medical Center, Columbus, Ohio. bResearch Author, Ohio State University, Columbus, Ohio. cPanel Chair, Mayo Clinic Arizona, Phoenix, Arizona. dUniversity of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. eMayo Clinic, Rochester, Minnesota. fHospital for Special Surgery, New York, New York. | 69358 |
acrac_69358_2 | Osteoporosis and Bone Mineral Density | gThe Ohio State University Wexner Medical Center, Columbus, Ohio, Primary care physician. hMedical University of South Carolina, Charleston, South Carolina; North American Spine Society. iDuke University Medical Center, Durham, North Carolina. jUniversity of Missouri Health Care, Columbia, Missouri. kCleveland Clinic, Cleveland, Ohio. lPenn State Milton S. Hershey Medical Center, Hershey, Pennsylvania, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania; Commission on Nuclear Medicine and Molecular Imaging. mPenn State Milton S. Hershey Medical Center, Hershey, Pennsylvania and Uniformed Services University of the Health Sciences, Bethesda, Maryland. nSpecialty Chair, University of Kentucky, Lexington, Kentucky. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: [email protected] Osteoporosis and Bone Mineral Density of osteoporosis, although it has research applications in determining alterations in the bone architecture. It should be noted that peripheral QCT is commonly performed in children [16]. Additional risk factors for osteoporosis include: a. Estrogen deficiency b. A history of maternal hip fracture that occurred after the age of 50 years c. Low body mass (<127 lb or 57.6 kg) d. History of amenorrhea (>1 year before 42 years of age) 3. Women <65 years of age or men <70 years of age who have additional risk factors, including: DXA DXA DXA is recommended for osteoporosis screening or initial imaging of clinically suspected low BMD. It is a clinically proven method of measuring BMD in the lumbar spine, proximal femur, forearm, and whole body. | Osteoporosis and Bone Mineral Density. gThe Ohio State University Wexner Medical Center, Columbus, Ohio, Primary care physician. hMedical University of South Carolina, Charleston, South Carolina; North American Spine Society. iDuke University Medical Center, Durham, North Carolina. jUniversity of Missouri Health Care, Columbia, Missouri. kCleveland Clinic, Cleveland, Ohio. lPenn State Milton S. Hershey Medical Center, Hershey, Pennsylvania, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania; Commission on Nuclear Medicine and Molecular Imaging. mPenn State Milton S. Hershey Medical Center, Hershey, Pennsylvania and Uniformed Services University of the Health Sciences, Bethesda, Maryland. nSpecialty Chair, University of Kentucky, Lexington, Kentucky. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: [email protected] Osteoporosis and Bone Mineral Density of osteoporosis, although it has research applications in determining alterations in the bone architecture. It should be noted that peripheral QCT is commonly performed in children [16]. Additional risk factors for osteoporosis include: a. Estrogen deficiency b. A history of maternal hip fracture that occurred after the age of 50 years c. Low body mass (<127 lb or 57.6 kg) d. History of amenorrhea (>1 year before 42 years of age) 3. Women <65 years of age or men <70 years of age who have additional risk factors, including: DXA DXA DXA is recommended for osteoporosis screening or initial imaging of clinically suspected low BMD. It is a clinically proven method of measuring BMD in the lumbar spine, proximal femur, forearm, and whole body. | 69358 |
acrac_69358_3 | Osteoporosis and Bone Mineral Density | BMD measurements derived from DXA has been shown to accurately predict fracture risk [18,19]. Epidemiological studies have demonstrated that BMD correlates to population fracture risk and amount of force necessary to fracture bone [20,21]. In a routine DXA study, 2 sites (the lumbar spine and hip) are reported. In the spine, a frontal projection measures up to 4 vertebral bodies from L1 to L4, and in the hip, a frontal projection measures 2 regions: the femoral neck and total hip [17]. In the event of a falsely elevated BMD of the lumbar spine caused by fracture, facet joint osteoarthritis, or spondylosis, up to 2 vertebral levels may be excluded from analysis. However, if exclusion of more than 2 vertebral body levels is necessary, then the second hip can be scanned as a substitute for the spine [22]. Alternatively, the distal one-third radius of the nondominant arm may be used as a third site in situations in which only one hip is available. Otherwise, the distal one-third radius is used primarily in patients with hyperparathyroidism. Primary hyperparathyroidism preferentially decreases mineralization at cortical-rich sites such as the hip and mid radius, in contrast to the predominantly cancellous bone of the lumbar spine [22]. Although DXA is an accurate screening tool, it remains underused. According to 2 recent reports, only 6.7% of patients underwent evaluation with DXA 6 months after sustaining a fragility fracture in 1 study, and only 8% of patients on long-term glucocorticoid therapy had follow-up DXAs [29,30]. Underutilization may lead to under- treatment in approximately 70% of these patients, and patients who are not adequately treated are at increased risk of incurring additional fractures in their lifetime [7,29]. QCT QCT QCT also provides volumetric BMD (vBMD), and both the trabecular and cortical bone compartments can be assessed [31,32]. | Osteoporosis and Bone Mineral Density. BMD measurements derived from DXA has been shown to accurately predict fracture risk [18,19]. Epidemiological studies have demonstrated that BMD correlates to population fracture risk and amount of force necessary to fracture bone [20,21]. In a routine DXA study, 2 sites (the lumbar spine and hip) are reported. In the spine, a frontal projection measures up to 4 vertebral bodies from L1 to L4, and in the hip, a frontal projection measures 2 regions: the femoral neck and total hip [17]. In the event of a falsely elevated BMD of the lumbar spine caused by fracture, facet joint osteoarthritis, or spondylosis, up to 2 vertebral levels may be excluded from analysis. However, if exclusion of more than 2 vertebral body levels is necessary, then the second hip can be scanned as a substitute for the spine [22]. Alternatively, the distal one-third radius of the nondominant arm may be used as a third site in situations in which only one hip is available. Otherwise, the distal one-third radius is used primarily in patients with hyperparathyroidism. Primary hyperparathyroidism preferentially decreases mineralization at cortical-rich sites such as the hip and mid radius, in contrast to the predominantly cancellous bone of the lumbar spine [22]. Although DXA is an accurate screening tool, it remains underused. According to 2 recent reports, only 6.7% of patients underwent evaluation with DXA 6 months after sustaining a fragility fracture in 1 study, and only 8% of patients on long-term glucocorticoid therapy had follow-up DXAs [29,30]. Underutilization may lead to under- treatment in approximately 70% of these patients, and patients who are not adequately treated are at increased risk of incurring additional fractures in their lifetime [7,29]. QCT QCT QCT also provides volumetric BMD (vBMD), and both the trabecular and cortical bone compartments can be assessed [31,32]. | 69358 |
acrac_69358_4 | Osteoporosis and Bone Mineral Density | QCT can be performed on a vast majority of commercially available CT scanners, provided they include densitometry analysis software and a calibration phantom. When interpreting QCT vBMD results, it is important to recognize 2 important differences to DXA. Z- and T-scores can be calculated from the vBMD, but the T-scores do not apply to the WHO definition of osteoporosis or osteopenia [31]. The exclusive application of the WHO classification is inherent to projectional BMD [25]. The ACR QCT cutoff values for low bone mass or osteopenia are 80 to 120 mg/mL and <80 mg/mL for osteoporosis [12]. Another major difference between QCT and DXA is related to monitoring. Spine BMD values measured by QCT demonstrate higher rates of bone loss with advancing age, principally because of the exclusive measurement of cancellous bone. The rate of change in cancellous bone is significantly greater than that of cortical bone. By contrast, the projectional properties of DXA summate the cortically predominant end plates and posterior elements with the cancellous vertebral body measurements, thereby decreasing their rate of change over time [31]. Indications for utilization of QCT as a screening modality are the same as DXA. However, in the setting of screening or initial imaging, QCT is regarded as a secondary tool to DXA. QCT may be considered as a primary imaging modality in certain conditions. Cases in which QCT is considered superior to DXA include extremes in height (very tall and very small patients), patients with obesity (BMI >35 kg/m2), patients with severe degenerative spine disease, and when an increased sensitivity to small changes in trabecular bone density is desired (parathyroid hormone and glucocorticoid treatment monitoring) [34]. It was recently reported that opportunistic QCTs of the lumbar spine was more predictive of spine fractures in neurological and oncologic patients than reference DXA scans, but there were only 84 patients in this study [35]. | Osteoporosis and Bone Mineral Density. QCT can be performed on a vast majority of commercially available CT scanners, provided they include densitometry analysis software and a calibration phantom. When interpreting QCT vBMD results, it is important to recognize 2 important differences to DXA. Z- and T-scores can be calculated from the vBMD, but the T-scores do not apply to the WHO definition of osteoporosis or osteopenia [31]. The exclusive application of the WHO classification is inherent to projectional BMD [25]. The ACR QCT cutoff values for low bone mass or osteopenia are 80 to 120 mg/mL and <80 mg/mL for osteoporosis [12]. Another major difference between QCT and DXA is related to monitoring. Spine BMD values measured by QCT demonstrate higher rates of bone loss with advancing age, principally because of the exclusive measurement of cancellous bone. The rate of change in cancellous bone is significantly greater than that of cortical bone. By contrast, the projectional properties of DXA summate the cortically predominant end plates and posterior elements with the cancellous vertebral body measurements, thereby decreasing their rate of change over time [31]. Indications for utilization of QCT as a screening modality are the same as DXA. However, in the setting of screening or initial imaging, QCT is regarded as a secondary tool to DXA. QCT may be considered as a primary imaging modality in certain conditions. Cases in which QCT is considered superior to DXA include extremes in height (very tall and very small patients), patients with obesity (BMI >35 kg/m2), patients with severe degenerative spine disease, and when an increased sensitivity to small changes in trabecular bone density is desired (parathyroid hormone and glucocorticoid treatment monitoring) [34]. It was recently reported that opportunistic QCTs of the lumbar spine was more predictive of spine fractures in neurological and oncologic patients than reference DXA scans, but there were only 84 patients in this study [35]. | 69358 |
acrac_69358_5 | Osteoporosis and Bone Mineral Density | QUS There is insufficient evidence to support the current use of quantitative ultrasound (QUS) as a screening tool in patients suspected of having osteoporosis or low BMD. Dense structural complexity demonstrates increased attenuation, whereas osteoporotic bone demonstrates lower velocities. The limitations of QUS are a lack of precision and sensitivity [36]. Dedicated QUS scanners are available for the calcaneus, phalanx, and tibia. However, the heel represents the only validated site for the clinical use of QUS. QUS does not measure BMD, and therefore, the WHO Osteoporosis and Bone Mineral Density classification system cannot be used and a diagnosis of osteoporosis cannot be made. Discordance between QUS and central DXA is not infrequent [37]. A recent meta-analysis conducted to assess the role of QUS in inflammatory rheumatic diseases came to the conclusion that the current literature does not support the substitution of QUS for DXA in the diagnosis and monitoring of osteoporosis in rheumatic diseases [38]. Radiography Appendicular Skeleton There is insufficient evidence to support the current use of radiography as a screening tool in patients suspected of having osteoporosis or low BMD. Radiography is a projectional X-ray-based technology that is widely used in current medical practice for rapid image acquisition for an extensive number of indications. Radiography use differences in electron density to generate contrast between different tissues, including bone. Although there are several standards used to identify demineralized bone on radiographs, radiography has a substantially lower sensitivity to bone loss than DXA. Osteopenia is not a reliable finding until 30% to 40% of the bone has been lost [39]. Patients who have radiographic evidence of osteopenia and/or fragility fractures should be referred to DXA for further characterization. | Osteoporosis and Bone Mineral Density. QUS There is insufficient evidence to support the current use of quantitative ultrasound (QUS) as a screening tool in patients suspected of having osteoporosis or low BMD. Dense structural complexity demonstrates increased attenuation, whereas osteoporotic bone demonstrates lower velocities. The limitations of QUS are a lack of precision and sensitivity [36]. Dedicated QUS scanners are available for the calcaneus, phalanx, and tibia. However, the heel represents the only validated site for the clinical use of QUS. QUS does not measure BMD, and therefore, the WHO Osteoporosis and Bone Mineral Density classification system cannot be used and a diagnosis of osteoporosis cannot be made. Discordance between QUS and central DXA is not infrequent [37]. A recent meta-analysis conducted to assess the role of QUS in inflammatory rheumatic diseases came to the conclusion that the current literature does not support the substitution of QUS for DXA in the diagnosis and monitoring of osteoporosis in rheumatic diseases [38]. Radiography Appendicular Skeleton There is insufficient evidence to support the current use of radiography as a screening tool in patients suspected of having osteoporosis or low BMD. Radiography is a projectional X-ray-based technology that is widely used in current medical practice for rapid image acquisition for an extensive number of indications. Radiography use differences in electron density to generate contrast between different tissues, including bone. Although there are several standards used to identify demineralized bone on radiographs, radiography has a substantially lower sensitivity to bone loss than DXA. Osteopenia is not a reliable finding until 30% to 40% of the bone has been lost [39]. Patients who have radiographic evidence of osteopenia and/or fragility fractures should be referred to DXA for further characterization. | 69358 |
acrac_69358_6 | Osteoporosis and Bone Mineral Density | Radiography Axial Skeleton There is insufficient evidence to support the current use of radiography as a screening tool in patients suspected of having osteoporosis or low BMD. Reportedly, patients with a low second metacarpal index may have a higher risk for developing hip fractures [40]. A recent study using artificial intelligence to segment metacarpal morphometry has shown potential as a screening tool with a sensitivity of 82.4% and specificity of 95.7% and a pipeline accuracy of nearly 94% [41]. Patients who have radiographic evidence of demineralization and/or fragility fractures should be referred to DXA for further characterization. SXA There is insufficient evidence to support the current use of single X-ray (SXA) in patients suspected of having osteoporosis or low BMD. SXA is a projectional X-ray-based technology that used one X-ray tube as a photon source and was shown to precisely measure BMD at the forearm. It is no longer widely used in current practice and has been supplanted by DXA. TBS Although DXA provides an accurate evaluation of BMD, it is not always an accurate predictor of fracture risk because there is considerable overlap between BMD values in individuals with and without fractures. Trabecular bone score (TBS) is an independent predictor of fracture risk because TBS values quantify bone microarchitecture, a determinant of bone strength [42]. This analytical tool performs textural analysis on 2-D lumbar spine DXA images and captures information by measuring grey-level variations from one pixel to adjacent pixels, providing 3- D bone characteristics such as trabecular number, trabecular separation, and the connectivity density [43]. There is evidence that TBS can differentiate between two 3-D microarchitectures that exhibit identical BMD measurements bone quality rather than bone quantity as measured by DXA, QCT, and ultrasound. | Osteoporosis and Bone Mineral Density. Radiography Axial Skeleton There is insufficient evidence to support the current use of radiography as a screening tool in patients suspected of having osteoporosis or low BMD. Reportedly, patients with a low second metacarpal index may have a higher risk for developing hip fractures [40]. A recent study using artificial intelligence to segment metacarpal morphometry has shown potential as a screening tool with a sensitivity of 82.4% and specificity of 95.7% and a pipeline accuracy of nearly 94% [41]. Patients who have radiographic evidence of demineralization and/or fragility fractures should be referred to DXA for further characterization. SXA There is insufficient evidence to support the current use of single X-ray (SXA) in patients suspected of having osteoporosis or low BMD. SXA is a projectional X-ray-based technology that used one X-ray tube as a photon source and was shown to precisely measure BMD at the forearm. It is no longer widely used in current practice and has been supplanted by DXA. TBS Although DXA provides an accurate evaluation of BMD, it is not always an accurate predictor of fracture risk because there is considerable overlap between BMD values in individuals with and without fractures. Trabecular bone score (TBS) is an independent predictor of fracture risk because TBS values quantify bone microarchitecture, a determinant of bone strength [42]. This analytical tool performs textural analysis on 2-D lumbar spine DXA images and captures information by measuring grey-level variations from one pixel to adjacent pixels, providing 3- D bone characteristics such as trabecular number, trabecular separation, and the connectivity density [43]. There is evidence that TBS can differentiate between two 3-D microarchitectures that exhibit identical BMD measurements bone quality rather than bone quantity as measured by DXA, QCT, and ultrasound. | 69358 |
acrac_69358_7 | Osteoporosis and Bone Mineral Density | Elevated values of TBS correlate with fracture resistance, whereas porous osteoporotic bone depict lower values than normal bone [44]. The advantages of TBS are that it can be assessed retrospectively from previously obtained DXA scans providing longitudinal data, and it is not impacted by the presence of overlying calcifications or degenerative changes in the spine [45]. In the setting of screening or initial imaging, TBS is regarded as an adjunct tool to DXA. However, TBS should not be used alone in clinical practice either to screen for osteoporosis or for treatment decisions [17]. TBS may be useful in certain populations. TBS when used in conjunction with BMD, clinical risk factors, and/or FRAX consistently enhances their accuracy [46-50]. Significantly reduced TBSs are associated with fragility fractures in secondary osteoporosis. In these patients, TBS has been found to have a substantially higher association with fracture risk than BMD [51,52]. TBSs in patients with type 2 diabetes, chronic renal disease, glucocorticoid therapy, rheumatoid arthritis, and hyperparathyroidism have demonstrated increased fracture risk, even in the setting of normal BMD [47,53]. Variant 2: Follow-up imaging of patients demonstrated to have risk for fracture or surveillance of established low bone mineral density. Follow-up imaging is recommended in patients who have increased risk for fracture, been previously diagnosed with osteopenia or osteoporosis, or initiated treatment for osteoporosis. Additionally, as outlined in Variant 3, vertebral fracture assessment (VFA) may be considered in patients with documented spine fractures or if they have Osteoporosis and Bone Mineral Density been diagnosed with osteopenia and meet certain age criteria, have experienced height loss or undocumented vertebral fractures (VFs), or have a history of use of glucocorticoid medication for >3 months. | Osteoporosis and Bone Mineral Density. Elevated values of TBS correlate with fracture resistance, whereas porous osteoporotic bone depict lower values than normal bone [44]. The advantages of TBS are that it can be assessed retrospectively from previously obtained DXA scans providing longitudinal data, and it is not impacted by the presence of overlying calcifications or degenerative changes in the spine [45]. In the setting of screening or initial imaging, TBS is regarded as an adjunct tool to DXA. However, TBS should not be used alone in clinical practice either to screen for osteoporosis or for treatment decisions [17]. TBS may be useful in certain populations. TBS when used in conjunction with BMD, clinical risk factors, and/or FRAX consistently enhances their accuracy [46-50]. Significantly reduced TBSs are associated with fragility fractures in secondary osteoporosis. In these patients, TBS has been found to have a substantially higher association with fracture risk than BMD [51,52]. TBSs in patients with type 2 diabetes, chronic renal disease, glucocorticoid therapy, rheumatoid arthritis, and hyperparathyroidism have demonstrated increased fracture risk, even in the setting of normal BMD [47,53]. Variant 2: Follow-up imaging of patients demonstrated to have risk for fracture or surveillance of established low bone mineral density. Follow-up imaging is recommended in patients who have increased risk for fracture, been previously diagnosed with osteopenia or osteoporosis, or initiated treatment for osteoporosis. Additionally, as outlined in Variant 3, vertebral fracture assessment (VFA) may be considered in patients with documented spine fractures or if they have Osteoporosis and Bone Mineral Density been diagnosed with osteopenia and meet certain age criteria, have experienced height loss or undocumented vertebral fractures (VFs), or have a history of use of glucocorticoid medication for >3 months. | 69358 |
acrac_69358_8 | Osteoporosis and Bone Mineral Density | When a nontreated patient has a statistically significant decrease in BMD on follow-up DXA, therapy initiation may be considered in the setting of confirmed primary osteoporosis or when there is clinical correlation identifying potential secondary causes of osteoporosis [57]. Serial BMD testing combined with clinical risk factors, bone turnover markers, and other factors such as height loss and TBS may also be used to determine whether treatment should be initiated. Patients receiving treatment who demonstrate decreasing BMD on follow-up scans may require an adjustment in their pharmacotherapy regimen [24]. In the majority of patients, the time interval for monitoring is based on the change rate of bone mineralization, which is typically about 2 years; however, it is preferable for this interval to be shorter (1 to <2 years) after therapy has been initiated [23]. Patients who are at high risk for a more rapid decline of bone mass, such as those receiving glucocorticoid therapy, also require shorter intervals between imaging; 1-year intervals after initiation or change of therapy is appropriate with progressively longer intervals once therapeutic effect is established [58]. Scan intervals <1 year are discouraged [24]. Serial BMD testing is encouraged in individuals after cessation of pharmacologic therapy for osteoporosis as well. DXA VFA In this setting, use of VFA is not supported. This differs from variant 3 in which VFA may be considered in patients with documented spine fractures or if they have been diagnosed with osteopenia and meet certain age criteria, have experienced height loss or undocumented VFs, or have a history of use of glucocorticoid medication for >3 months [17]. QCT QCT is regarded as a secondary or adjunct tool to DXA. QCT may be useful in unique populations in which there is a need for added precision. | Osteoporosis and Bone Mineral Density. When a nontreated patient has a statistically significant decrease in BMD on follow-up DXA, therapy initiation may be considered in the setting of confirmed primary osteoporosis or when there is clinical correlation identifying potential secondary causes of osteoporosis [57]. Serial BMD testing combined with clinical risk factors, bone turnover markers, and other factors such as height loss and TBS may also be used to determine whether treatment should be initiated. Patients receiving treatment who demonstrate decreasing BMD on follow-up scans may require an adjustment in their pharmacotherapy regimen [24]. In the majority of patients, the time interval for monitoring is based on the change rate of bone mineralization, which is typically about 2 years; however, it is preferable for this interval to be shorter (1 to <2 years) after therapy has been initiated [23]. Patients who are at high risk for a more rapid decline of bone mass, such as those receiving glucocorticoid therapy, also require shorter intervals between imaging; 1-year intervals after initiation or change of therapy is appropriate with progressively longer intervals once therapeutic effect is established [58]. Scan intervals <1 year are discouraged [24]. Serial BMD testing is encouraged in individuals after cessation of pharmacologic therapy for osteoporosis as well. DXA VFA In this setting, use of VFA is not supported. This differs from variant 3 in which VFA may be considered in patients with documented spine fractures or if they have been diagnosed with osteopenia and meet certain age criteria, have experienced height loss or undocumented VFs, or have a history of use of glucocorticoid medication for >3 months [17]. QCT QCT is regarded as a secondary or adjunct tool to DXA. QCT may be useful in unique populations in which there is a need for added precision. | 69358 |
acrac_69358_9 | Osteoporosis and Bone Mineral Density | QCT demonstrates excellent precision and reproducibility to changes and can be used for the monitoring of BMD in untreated and treated patients provided that there is routine calibration [22]. QCT is more sensitive to change than DXA because it detects mineralization in the cancellous bone, the portion of bone most sensitive to rapid changes, as well as at the cortex, such as newly formed bone in the cortical and subcortical compartments [61-63]. Femoral neck and total hip T-scores calculated from follow-up projectional QCT data are equivalent to corresponding DXA T-scores for monitoring of osteoporosis in accordance to the WHO criteria, and can be used longitudinally [22]. QUS There is insufficient evidence to the support the routine use of QUS for monitoring of untreated and treated patients. SXA There is insufficient evidence to the support the routine use of SXA for monitoring of untreated and treated patients. Osteoporosis and Bone Mineral Density TBS TBS is regarded as an adjunct tool to DXA. TBS may be useful in a small population where there is a need to look at marginal changes beyond BMD. TBS may be of benefit stratifying risk in individuals with relatively normal or osteopenic BMD values because most fractures occur in this subset of nonosteoporotic patients. Multiple studies have shown associations of TBS with fractures in postmenopausal women as well as a few fractures in men [64- 68]. DXA Follow-up DXA is supported for monitoring patients who have low BMD and VF risk factors [56]. DXA VFA In their 2019 guidelines, the ISCD recommended that densitometric spine imaging, or VFA, be considered for the listed indications in this variant [17]. VFA is a feature of DXA scanners in which a lateral thoracic and lumbar spine image from T5 to L5 is provided for the purpose of detecting vertebral body deformities; most VFs occur between the T7 and L4 levels [77]. | Osteoporosis and Bone Mineral Density. QCT demonstrates excellent precision and reproducibility to changes and can be used for the monitoring of BMD in untreated and treated patients provided that there is routine calibration [22]. QCT is more sensitive to change than DXA because it detects mineralization in the cancellous bone, the portion of bone most sensitive to rapid changes, as well as at the cortex, such as newly formed bone in the cortical and subcortical compartments [61-63]. Femoral neck and total hip T-scores calculated from follow-up projectional QCT data are equivalent to corresponding DXA T-scores for monitoring of osteoporosis in accordance to the WHO criteria, and can be used longitudinally [22]. QUS There is insufficient evidence to the support the routine use of QUS for monitoring of untreated and treated patients. SXA There is insufficient evidence to the support the routine use of SXA for monitoring of untreated and treated patients. Osteoporosis and Bone Mineral Density TBS TBS is regarded as an adjunct tool to DXA. TBS may be useful in a small population where there is a need to look at marginal changes beyond BMD. TBS may be of benefit stratifying risk in individuals with relatively normal or osteopenic BMD values because most fractures occur in this subset of nonosteoporotic patients. Multiple studies have shown associations of TBS with fractures in postmenopausal women as well as a few fractures in men [64- 68]. DXA Follow-up DXA is supported for monitoring patients who have low BMD and VF risk factors [56]. DXA VFA In their 2019 guidelines, the ISCD recommended that densitometric spine imaging, or VFA, be considered for the listed indications in this variant [17]. VFA is a feature of DXA scanners in which a lateral thoracic and lumbar spine image from T5 to L5 is provided for the purpose of detecting vertebral body deformities; most VFs occur between the T7 and L4 levels [77]. | 69358 |
acrac_69358_10 | Osteoporosis and Bone Mineral Density | This procedure is complementary to DXA; the image is obtained during the DXA session and represents a point-of-care service. A semiquantitative visual method used for diagnosis characterizes the morphology based on shape (wedge, concave, or crush) and location (anterior, posterior, and/or middle) and the total number of involved vertebrae [78,79]. In general, grade 2 fractures (moderate or 26%-40% reduction) and grade 3 fractures (severe or >40% reduction) are more predictive of future fractures than grade 1 fractures (mild or 20%-25% reduction), which have a greater overlap with nonfracture deformities [80]. A solitary, asymptomatic grade 1 fracture is likely to be minimal to no clinical significance, whereas a grade 3 fracture is an important predictor of fracture risk not only in the spine but also in nonvertebral sites [81]. It is estimated that two-thirds of radiographically evident VFs are not recognized clinically and are incidentally detected [82]. Numerous epidemiologic studies have provided the incidence and prevalence of VFs in different populations [83-85]. The risk for developing a VF rises substantially in women after >70 years of age and in men >80 years of age [86-88]. In patients with chronic exposure to glucocorticoid medication, the prevalence of VF is >50% in those >70 years of age, approximately 17% in patients treated for autoimmune disease, and 22% in patients with Crohn disease [89-91]. The incidence is 2 to 2.5 times higher in women than in men [77]. The utility of VFA is identifying patients who would not otherwise qualify for treatment under the guidelines of the NOF, which are based solely on BMD measurements. Multiple studies have demonstrated populations of patients who were reclassified because of detection of VFs [92-95]. A study in the Netherlands demonstrated that 60% of patients with a fracture on VFA were in the nonosteoporotic range, and of these, 74% were previously unknown to have fractures [92]. | Osteoporosis and Bone Mineral Density. This procedure is complementary to DXA; the image is obtained during the DXA session and represents a point-of-care service. A semiquantitative visual method used for diagnosis characterizes the morphology based on shape (wedge, concave, or crush) and location (anterior, posterior, and/or middle) and the total number of involved vertebrae [78,79]. In general, grade 2 fractures (moderate or 26%-40% reduction) and grade 3 fractures (severe or >40% reduction) are more predictive of future fractures than grade 1 fractures (mild or 20%-25% reduction), which have a greater overlap with nonfracture deformities [80]. A solitary, asymptomatic grade 1 fracture is likely to be minimal to no clinical significance, whereas a grade 3 fracture is an important predictor of fracture risk not only in the spine but also in nonvertebral sites [81]. It is estimated that two-thirds of radiographically evident VFs are not recognized clinically and are incidentally detected [82]. Numerous epidemiologic studies have provided the incidence and prevalence of VFs in different populations [83-85]. The risk for developing a VF rises substantially in women after >70 years of age and in men >80 years of age [86-88]. In patients with chronic exposure to glucocorticoid medication, the prevalence of VF is >50% in those >70 years of age, approximately 17% in patients treated for autoimmune disease, and 22% in patients with Crohn disease [89-91]. The incidence is 2 to 2.5 times higher in women than in men [77]. The utility of VFA is identifying patients who would not otherwise qualify for treatment under the guidelines of the NOF, which are based solely on BMD measurements. Multiple studies have demonstrated populations of patients who were reclassified because of detection of VFs [92-95]. A study in the Netherlands demonstrated that 60% of patients with a fracture on VFA were in the nonosteoporotic range, and of these, 74% were previously unknown to have fractures [92]. | 69358 |
acrac_69358_11 | Osteoporosis and Bone Mineral Density | In another recent study of postmenopausal women, 17.2% of patients had their diagnosis upgraded to severe osteoporosis owing to VFs diagnosed on VFA [96]. A meta-analysis based on VFA-detected VFs reported that among women who had prevalent VFs, up to 43% had low BMD (osteopenia), and up to 32% had normal bone density [76]. Detection of unknown VFs influences initiating therapy in asymptomatic patients as well as guides therapeutic decisions in treated patients whose BMD may have remained stable or shown improvement on DXA [97]. Osteoporosis and Bone Mineral Density QCT QCT is regarded as a secondary or adjunct tool to DXA. It may be considered as a primary modality in cases in which there is severe degenerative disease of the spine or significant scoliosis (see Variant 6) and when it is desirable to have higher spatial resolution to optimize bone detail. QUS There is insufficient evidence to support the use of QUS to image the spine. Radiography Appendicular Skeleton There is insufficient evidence to support the use of appendicular radiography to image the spine. Radiography Axial Skeleton Lateral radiographs of the spine may be considered when VFA is not diagnostic or when images cannot be adequately derived. Additionally, radiographs of the spine may be considered as an alternative to VFA in patients who have low BMD and risk factors for developing VFs [17]. The benefit of radiography over VFA is superior spatial resolution. The sharp delineation of the end plates and cortical margins affirms confident detection of subtle Genant grade 1 fractures [98]. When reporting the severity of a vertebral body defect, the semiquantitative methodology by Genant should be used [78]. SXA There is insufficient evidence to support the use of SXA to image the spine. TBS TBS is regarded as an adjunct tool to DXA. TBS may be useful in a small population in which there is a need to look at marginal changes beyond BMD. | Osteoporosis and Bone Mineral Density. In another recent study of postmenopausal women, 17.2% of patients had their diagnosis upgraded to severe osteoporosis owing to VFs diagnosed on VFA [96]. A meta-analysis based on VFA-detected VFs reported that among women who had prevalent VFs, up to 43% had low BMD (osteopenia), and up to 32% had normal bone density [76]. Detection of unknown VFs influences initiating therapy in asymptomatic patients as well as guides therapeutic decisions in treated patients whose BMD may have remained stable or shown improvement on DXA [97]. Osteoporosis and Bone Mineral Density QCT QCT is regarded as a secondary or adjunct tool to DXA. It may be considered as a primary modality in cases in which there is severe degenerative disease of the spine or significant scoliosis (see Variant 6) and when it is desirable to have higher spatial resolution to optimize bone detail. QUS There is insufficient evidence to support the use of QUS to image the spine. Radiography Appendicular Skeleton There is insufficient evidence to support the use of appendicular radiography to image the spine. Radiography Axial Skeleton Lateral radiographs of the spine may be considered when VFA is not diagnostic or when images cannot be adequately derived. Additionally, radiographs of the spine may be considered as an alternative to VFA in patients who have low BMD and risk factors for developing VFs [17]. The benefit of radiography over VFA is superior spatial resolution. The sharp delineation of the end plates and cortical margins affirms confident detection of subtle Genant grade 1 fractures [98]. When reporting the severity of a vertebral body defect, the semiquantitative methodology by Genant should be used [78]. SXA There is insufficient evidence to support the use of SXA to image the spine. TBS TBS is regarded as an adjunct tool to DXA. TBS may be useful in a small population in which there is a need to look at marginal changes beyond BMD. | 69358 |
acrac_69358_12 | Osteoporosis and Bone Mineral Density | TBS enhances FRAX in patients whose BMD level lies close to the intervention threshold and may provide data that facilitates treatment decisions, but TBS should not be used by itself in monitoring patients with VF risk factors [47]. Variant 4: Initial imaging for premenopausal females or males less than 50 years of age. Individual with risk factors that could alter bone mineral density. 1. Individuals with medical conditions that could alter BMD, such as: DXA The data providing imaging guidance in premenopausal women are few. The literature indicates that DXA remains the primary screening modality for evaluating bone mineralization in patients with these clinical scenarios [99]. Screening BMD should not be performed in premenopausal women. The 2 exceptions are young women with a history of fractures from minor trauma and those who have known causes of bone loss [100,101]. Chronic disease damage and low BMI are reported as risks factors for low BMD in premenopausal systemic lupus erythematosus patients, and early monitoring and/or treatment may prevent severe bone loss and future fractures [102]. In the 2017 American College of Rheumatology guidelines on glucocorticoid-induced osteoporosis, adults receiving Osteoporosis and Bone Mineral Density glucocorticoid therapy for >3 months and who have had a prior fracture or other risk factors should have their BMD evaluated every 2 to 3 years [103]. In organ transplant patients, owing to rapid bone loss in the first 6 to 12 months after transplantation, the same imaging guideline was proposed [103]. A baseline DXA should be considered in women age <40 years of age who experience premature menopause for any reason, especially when menopause was induced by chemotherapy. In untreated women undergoing initiation of an aromatase inhibitor, bone loss is most marked in the 12 to 24 months [104]. Men who undergo androgen deprivation therapy have substantially elevated risk of fracture. | Osteoporosis and Bone Mineral Density. TBS enhances FRAX in patients whose BMD level lies close to the intervention threshold and may provide data that facilitates treatment decisions, but TBS should not be used by itself in monitoring patients with VF risk factors [47]. Variant 4: Initial imaging for premenopausal females or males less than 50 years of age. Individual with risk factors that could alter bone mineral density. 1. Individuals with medical conditions that could alter BMD, such as: DXA The data providing imaging guidance in premenopausal women are few. The literature indicates that DXA remains the primary screening modality for evaluating bone mineralization in patients with these clinical scenarios [99]. Screening BMD should not be performed in premenopausal women. The 2 exceptions are young women with a history of fractures from minor trauma and those who have known causes of bone loss [100,101]. Chronic disease damage and low BMI are reported as risks factors for low BMD in premenopausal systemic lupus erythematosus patients, and early monitoring and/or treatment may prevent severe bone loss and future fractures [102]. In the 2017 American College of Rheumatology guidelines on glucocorticoid-induced osteoporosis, adults receiving Osteoporosis and Bone Mineral Density glucocorticoid therapy for >3 months and who have had a prior fracture or other risk factors should have their BMD evaluated every 2 to 3 years [103]. In organ transplant patients, owing to rapid bone loss in the first 6 to 12 months after transplantation, the same imaging guideline was proposed [103]. A baseline DXA should be considered in women age <40 years of age who experience premature menopause for any reason, especially when menopause was induced by chemotherapy. In untreated women undergoing initiation of an aromatase inhibitor, bone loss is most marked in the 12 to 24 months [104]. Men who undergo androgen deprivation therapy have substantially elevated risk of fracture. | 69358 |
acrac_69358_13 | Osteoporosis and Bone Mineral Density | A baseline DXA study in men receiving androgen deprivation therapy should be considered after 6 months of therapy [105]. QUS There is insufficient evidence to support the use of QUS as a screening study in this group of patients. The correlation between QUS parameters and DXA has been reported to be lower in premenopausal women than in postmenopausal women and not predictive of osteoporosis [109]. Radiography Appendicular Skeleton There is insufficient evidence to support the use of radiography appendicular skeleton as a screening study in this group of patients. Radiography Axial Skeleton There is insufficient evidence to support the use of radiography axial skeleton as a screening study in this group of patients. SXA There is insufficient evidence to support the use of SXA as a screening study in this group of patients. TBS There is insufficient evidence to support the use of TBS as a screening study in this group of patients. Variant 5: Premenopausal females with risk factors. Males less than 50 years of age with risk factors. Follow- up to low bone mineral density. 1. Individuals with medical conditions that could alter BMD, such as: Osteoporosis and Bone Mineral Density h. Individuals with an endocrine disorder known to adversely affect BMD (eg, hyperparathyroidism, hyperthyroidism, or Cushing syndrome) 2. Individuals receiving (or expected to receive) glucocorticoid therapy for >3 months 3. Hypogonadal men >18 years of age and men with surgically or chemotherapeutically induced castration 4. Individuals beginning or receiving long-term therapy with medications known to adversely affect BMD (eg, anticonvulsant drugs, androgen deprivation therapy, aromatase inhibitor therapy, or chronic heparin). Follow-up for premenopausal women as well as for men 20 to <50 years of age is based on the underlying clinical conditions listed. | Osteoporosis and Bone Mineral Density. A baseline DXA study in men receiving androgen deprivation therapy should be considered after 6 months of therapy [105]. QUS There is insufficient evidence to support the use of QUS as a screening study in this group of patients. The correlation between QUS parameters and DXA has been reported to be lower in premenopausal women than in postmenopausal women and not predictive of osteoporosis [109]. Radiography Appendicular Skeleton There is insufficient evidence to support the use of radiography appendicular skeleton as a screening study in this group of patients. Radiography Axial Skeleton There is insufficient evidence to support the use of radiography axial skeleton as a screening study in this group of patients. SXA There is insufficient evidence to support the use of SXA as a screening study in this group of patients. TBS There is insufficient evidence to support the use of TBS as a screening study in this group of patients. Variant 5: Premenopausal females with risk factors. Males less than 50 years of age with risk factors. Follow- up to low bone mineral density. 1. Individuals with medical conditions that could alter BMD, such as: Osteoporosis and Bone Mineral Density h. Individuals with an endocrine disorder known to adversely affect BMD (eg, hyperparathyroidism, hyperthyroidism, or Cushing syndrome) 2. Individuals receiving (or expected to receive) glucocorticoid therapy for >3 months 3. Hypogonadal men >18 years of age and men with surgically or chemotherapeutically induced castration 4. Individuals beginning or receiving long-term therapy with medications known to adversely affect BMD (eg, anticonvulsant drugs, androgen deprivation therapy, aromatase inhibitor therapy, or chronic heparin). Follow-up for premenopausal women as well as for men 20 to <50 years of age is based on the underlying clinical conditions listed. | 69358 |
acrac_69358_14 | Osteoporosis and Bone Mineral Density | Most expert groups recommend monitoring time interval of 1 to 2 years if there is a high risk for accelerated bone loss, but otherwise every 2 years if there are risk factors [24]. DXA The literature indicates that DXA is the primary modality by which to monitor BMD in premenopausal women as well as adult men <50 years of age with risk factors [24]. The need for follow-up DXA is dictated by the clinical circumstance of the patients. QCT QCT is regarded as a secondary or adjunct tool to DXA. QCT may allow for monitoring BMD in premenopausal women and men between 20 to 50 years of age with risk factors. QCT demonstrates excellent precision and reproducibility to changes [31]. QUS There is insufficient evidence to support the use of QUS to monitor premenopausal women or adult men <50 years of age with risk factors. SXA There is insufficient evidence to support the use of SXA to monitor premenopausal women or adult men <50 years of age with risk factors. TBS There is insufficient evidence to support the use of TBS to monitor premenopausal women or adult men <50 years of age with risk factors. Variant 6: Males and females greater than or equal to 50 years of age. Suspected osteoporosis. Advanced degenerative changes of the spine with or without scoliosis, or other conditions that may spuriously elevate BMD. Initial imaging. DXA DXA allows for screening patients with risk factors and advanced degenerative changes in the spine. In a routine DXA examination, both the lumbar spine and hip are scanned and measured. Owing to the projectional nature of DXA, spuriously elevated BMD values of the lumbar spine may be caused by spondylosis and degenerative facet osteoarthritis or dense overlying tissue. Reportedly, in examinations with falsely elevated measurements, the most common cause (>81%) is degenerative disease of the spine [110]. The ISCD recommends close inspection of the images and associated BMD values to monitor levels for exclusion. | Osteoporosis and Bone Mineral Density. Most expert groups recommend monitoring time interval of 1 to 2 years if there is a high risk for accelerated bone loss, but otherwise every 2 years if there are risk factors [24]. DXA The literature indicates that DXA is the primary modality by which to monitor BMD in premenopausal women as well as adult men <50 years of age with risk factors [24]. The need for follow-up DXA is dictated by the clinical circumstance of the patients. QCT QCT is regarded as a secondary or adjunct tool to DXA. QCT may allow for monitoring BMD in premenopausal women and men between 20 to 50 years of age with risk factors. QCT demonstrates excellent precision and reproducibility to changes [31]. QUS There is insufficient evidence to support the use of QUS to monitor premenopausal women or adult men <50 years of age with risk factors. SXA There is insufficient evidence to support the use of SXA to monitor premenopausal women or adult men <50 years of age with risk factors. TBS There is insufficient evidence to support the use of TBS to monitor premenopausal women or adult men <50 years of age with risk factors. Variant 6: Males and females greater than or equal to 50 years of age. Suspected osteoporosis. Advanced degenerative changes of the spine with or without scoliosis, or other conditions that may spuriously elevate BMD. Initial imaging. DXA DXA allows for screening patients with risk factors and advanced degenerative changes in the spine. In a routine DXA examination, both the lumbar spine and hip are scanned and measured. Owing to the projectional nature of DXA, spuriously elevated BMD values of the lumbar spine may be caused by spondylosis and degenerative facet osteoarthritis or dense overlying tissue. Reportedly, in examinations with falsely elevated measurements, the most common cause (>81%) is degenerative disease of the spine [110]. The ISCD recommends close inspection of the images and associated BMD values to monitor levels for exclusion. | 69358 |
acrac_69358_15 | Osteoporosis and Bone Mineral Density | In patients with ankylosing spondylitis, a moderate correlation and fair agreement between the T-scores of hip and the lumbar spine has been reported, suggesting that DXA of the hip and the lumbar spine may both be useful for screening in patients with ankylosing spondylitis without fused spines [111]. In addition to degenerative changes in the spine, BMD measurements using DXA may also be spuriously elevated in patients with hemoglobinopathies who have an iron-overloaded liver and in patients with severe abdominal calcifications [112,113]. QCT The literature indicates that QCT is ideally suited for the evaluation of the spine in the setting of advanced degeneration of the spine; it is preferred over DXA for monitoring under these conditions as well. Because it selectively samples only the cancellous portion of the vertebral body and excludes the end plates, cortices, and posterior elements, BMD using QCT is generally not negatively impacted by arthritis in the spine and has greater sensitivity to change than in DXA in this group of patients [32,114]. It also may provide adjunctive information in preoperative patients who may have diminished bone density [115]. Osteoporosis and Bone Mineral Density QUS There is insufficient evidence to support the use of QUS as a screening study for low BMD in patients with advanced degenerative changes in the spine. Radiography Appendicular Skeleton There is insufficient evidence to support the use of radiography appendicular skeleton as a screening study for low BMD in patients with advanced degenerative changes in the spine. Radiography Axial Skeleton There is insufficient evidence to support the use of radiography axial skeleton as a screening study for low BMD in patients with advanced degenerative changes in the spine. SXA There is insufficient evidence to support the use of SXA as a screening tool for low BMD in patients with advanced degenerative changes in the spine. | Osteoporosis and Bone Mineral Density. In patients with ankylosing spondylitis, a moderate correlation and fair agreement between the T-scores of hip and the lumbar spine has been reported, suggesting that DXA of the hip and the lumbar spine may both be useful for screening in patients with ankylosing spondylitis without fused spines [111]. In addition to degenerative changes in the spine, BMD measurements using DXA may also be spuriously elevated in patients with hemoglobinopathies who have an iron-overloaded liver and in patients with severe abdominal calcifications [112,113]. QCT The literature indicates that QCT is ideally suited for the evaluation of the spine in the setting of advanced degeneration of the spine; it is preferred over DXA for monitoring under these conditions as well. Because it selectively samples only the cancellous portion of the vertebral body and excludes the end plates, cortices, and posterior elements, BMD using QCT is generally not negatively impacted by arthritis in the spine and has greater sensitivity to change than in DXA in this group of patients [32,114]. It also may provide adjunctive information in preoperative patients who may have diminished bone density [115]. Osteoporosis and Bone Mineral Density QUS There is insufficient evidence to support the use of QUS as a screening study for low BMD in patients with advanced degenerative changes in the spine. Radiography Appendicular Skeleton There is insufficient evidence to support the use of radiography appendicular skeleton as a screening study for low BMD in patients with advanced degenerative changes in the spine. Radiography Axial Skeleton There is insufficient evidence to support the use of radiography axial skeleton as a screening study for low BMD in patients with advanced degenerative changes in the spine. SXA There is insufficient evidence to support the use of SXA as a screening tool for low BMD in patients with advanced degenerative changes in the spine. | 69358 |
acrac_70909_0 | Imaging of Mesenteric Ischemia | Introduction/Background Mesenteric ischemia is an uncommon disease affecting the small and large bowel resulting from a reduction of intestinal blood flow. Although the disease is responsible for fewer than 1 in 1,000 hospital admissions, the mortality rate remains high, ranging between 30% to 90% in acute settings despite advances in treatment options [1-4]. The etiology of ischemia may vary from arterial occlusion, venous thrombosis, or vasoconstriction. Higher prevalence in the elderly population and nonspecific clinical presentation leading to delayed diagnosis contribute to the high mortality rate [1]. Most cases of mesenteric ischemia are due to an acute event leading to decreased blood supply to the splanchnic vasculature. Chronic mesenteric ischemia is uncommon, accounting for <5% of cases of mesenteric ischemia, and is almost always associated with diffuse atherosclerotic disease [5]. Acute embolization of the SMA involves the distal aspect of the vessel, usually beyond the origin of the middle colic artery, and commonly does not have associated collateral vessels. Acute mesenteric artery thrombosis is typically associated with chronic atherosclerotic disease and, given its more insidious course, a well-developed collateral circulation is commonly present. Nonocclusive mesenteric ischemia is seen in the setting of hypoperfusion because of secondary vasoconstriction of the mesenteric arteries. In these cases, there is no evidence of vascular occlusion, and the ischemia is distributed over a wider area of the bowel in a nonconsecutive manner [9]. Mesenteric and portal venous thrombosis is the least common cause of acute mesenteric ischemia and may be idiopathic. Most common risk factors are hypercoagulable states, portal hypertension, and recent surgery [10,11]. Bowel ischemia results from impaired intestinal mucosa venous outflow, leading to visceral edema and subsequent arterial hypoperfusion. | Imaging of Mesenteric Ischemia. Introduction/Background Mesenteric ischemia is an uncommon disease affecting the small and large bowel resulting from a reduction of intestinal blood flow. Although the disease is responsible for fewer than 1 in 1,000 hospital admissions, the mortality rate remains high, ranging between 30% to 90% in acute settings despite advances in treatment options [1-4]. The etiology of ischemia may vary from arterial occlusion, venous thrombosis, or vasoconstriction. Higher prevalence in the elderly population and nonspecific clinical presentation leading to delayed diagnosis contribute to the high mortality rate [1]. Most cases of mesenteric ischemia are due to an acute event leading to decreased blood supply to the splanchnic vasculature. Chronic mesenteric ischemia is uncommon, accounting for <5% of cases of mesenteric ischemia, and is almost always associated with diffuse atherosclerotic disease [5]. Acute embolization of the SMA involves the distal aspect of the vessel, usually beyond the origin of the middle colic artery, and commonly does not have associated collateral vessels. Acute mesenteric artery thrombosis is typically associated with chronic atherosclerotic disease and, given its more insidious course, a well-developed collateral circulation is commonly present. Nonocclusive mesenteric ischemia is seen in the setting of hypoperfusion because of secondary vasoconstriction of the mesenteric arteries. In these cases, there is no evidence of vascular occlusion, and the ischemia is distributed over a wider area of the bowel in a nonconsecutive manner [9]. Mesenteric and portal venous thrombosis is the least common cause of acute mesenteric ischemia and may be idiopathic. Most common risk factors are hypercoagulable states, portal hypertension, and recent surgery [10,11]. Bowel ischemia results from impaired intestinal mucosa venous outflow, leading to visceral edema and subsequent arterial hypoperfusion. | 70909 |
acrac_70909_1 | Imaging of Mesenteric Ischemia | Chronic mesenteric ischemia occurs because of occlusive or stenotic atherosclerotic disease and most commonly involves at least 2 or 3 main vessels. It is more prevalent in the elderly population and in patients with major risk factors for atherosclerosis, such as hypertension, hyperlipidemia, and smoking history [12]. Discussion of Procedures by Variant Variant 1: Suspected acute mesenteric ischemia. Initial Imaging. Patients with acute mesenteric ischemia present with abdominal pain out of proportion to the physical examination [2]. A high index of suspicion is necessary to achieve early diagnosis, particularly in the elderly or hospitalized patient population [13,14]. The main challenge is to differentiate acute mesenteric ischemia from Reprint requests to: [email protected] Imaging of Mesenteric Ischemia other more common causes of acute abdominal pain, such as appendicitis, diverticulitis, peptic ulcer disease, acute pancreatitis, gastroenterocolitis, nephrolithiasis, cholelithiasis, and cholecystitis. Early in the course of disease, laboratory findings are of little value in differentiating among these causes, with the results usually demonstrating metabolic acidosis, elevated lactate and D-dimer, leukocytosis, hemoconcentration, elevated amylase levels, and/or abnormal liver enzymes [15,16]. Unfortunately, the signs, symptoms, and laboratory testing are insufficient for making the diagnosis [15]. Radiography Abdomen Radiography has historically been considered the first imaging modality in the evaluation of acute abdominal pain, but because of its low diagnostic yield and generally nonspecific findings, its role has been debated in current practice [17]. Abdominal radiography does not exclude the diagnosis of acute mesenteric ischemia as 25% of patients with this condition will have normal radiographs [18]. | Imaging of Mesenteric Ischemia. Chronic mesenteric ischemia occurs because of occlusive or stenotic atherosclerotic disease and most commonly involves at least 2 or 3 main vessels. It is more prevalent in the elderly population and in patients with major risk factors for atherosclerosis, such as hypertension, hyperlipidemia, and smoking history [12]. Discussion of Procedures by Variant Variant 1: Suspected acute mesenteric ischemia. Initial Imaging. Patients with acute mesenteric ischemia present with abdominal pain out of proportion to the physical examination [2]. A high index of suspicion is necessary to achieve early diagnosis, particularly in the elderly or hospitalized patient population [13,14]. The main challenge is to differentiate acute mesenteric ischemia from Reprint requests to: [email protected] Imaging of Mesenteric Ischemia other more common causes of acute abdominal pain, such as appendicitis, diverticulitis, peptic ulcer disease, acute pancreatitis, gastroenterocolitis, nephrolithiasis, cholelithiasis, and cholecystitis. Early in the course of disease, laboratory findings are of little value in differentiating among these causes, with the results usually demonstrating metabolic acidosis, elevated lactate and D-dimer, leukocytosis, hemoconcentration, elevated amylase levels, and/or abnormal liver enzymes [15,16]. Unfortunately, the signs, symptoms, and laboratory testing are insufficient for making the diagnosis [15]. Radiography Abdomen Radiography has historically been considered the first imaging modality in the evaluation of acute abdominal pain, but because of its low diagnostic yield and generally nonspecific findings, its role has been debated in current practice [17]. Abdominal radiography does not exclude the diagnosis of acute mesenteric ischemia as 25% of patients with this condition will have normal radiographs [18]. | 70909 |
acrac_70909_2 | Imaging of Mesenteric Ischemia | Radiography findings in patients with acute mesenteric ischemia are usually nonspecific, late, and associated with a high mortality rate, as they often first appear when bowel infarction has already occurred [5,18-20]. A radiograph typically shows bowel dilatation in elderly patients and a gasless abdomen in younger patients with acute mesenteric ischemia [21]. Hepatic portal venous gas is a rare but important radiographic finding associated with several pathological processes, including bowel necrosis secondary to acute mesenteric ischemia. Portal venous gas can occur alone or in association with pneumatosis intestinalis. When associated with pneumatosis intestinalis, it usually indicates the presence of advanced mesenteric ischemia [18]. In addition, given its limited role in assessing for other causes of acute abdominal pain, radiographs in mesenteric ischemia should be solely utilized to screen for bowel perforation or obstruction [17]. All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and recons/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. CTA of the abdomen and pelvis is a fast, accurate, and noninvasive diagnostic tool for evaluating the bowel and assessing intestinal vasculature and should be the first-step imaging approach in patients with acute bowel ischemia [12,15,23-28]. CTA can be helpful in stratifying patients to identify those who would benefit from angiography as opposed to the ones who should undergo emergent surgery. Grading the degree of arterial stenosis with CTA has also been shown to be highly accurate compared to digital subtraction imaging (DSA) as well as other imaging modalities, including US and MRA [29]. | Imaging of Mesenteric Ischemia. Radiography findings in patients with acute mesenteric ischemia are usually nonspecific, late, and associated with a high mortality rate, as they often first appear when bowel infarction has already occurred [5,18-20]. A radiograph typically shows bowel dilatation in elderly patients and a gasless abdomen in younger patients with acute mesenteric ischemia [21]. Hepatic portal venous gas is a rare but important radiographic finding associated with several pathological processes, including bowel necrosis secondary to acute mesenteric ischemia. Portal venous gas can occur alone or in association with pneumatosis intestinalis. When associated with pneumatosis intestinalis, it usually indicates the presence of advanced mesenteric ischemia [18]. In addition, given its limited role in assessing for other causes of acute abdominal pain, radiographs in mesenteric ischemia should be solely utilized to screen for bowel perforation or obstruction [17]. All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and recons/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. CTA of the abdomen and pelvis is a fast, accurate, and noninvasive diagnostic tool for evaluating the bowel and assessing intestinal vasculature and should be the first-step imaging approach in patients with acute bowel ischemia [12,15,23-28]. CTA can be helpful in stratifying patients to identify those who would benefit from angiography as opposed to the ones who should undergo emergent surgery. Grading the degree of arterial stenosis with CTA has also been shown to be highly accurate compared to digital subtraction imaging (DSA) as well as other imaging modalities, including US and MRA [29]. | 70909 |
acrac_70909_3 | Imaging of Mesenteric Ischemia | A negative or neutral oral contrast, such as low-density barium sulfate or water, has been advocated to distend the small bowel and better evaluate the bowel wall for thickening and enhancement; however this may not be possible in the acute setting [30]. Both arterial and portal venous phases should be included as part of the protocol to assess both arterial and venous patency [25,30,31]. Three-dimensional (3-D) rendering may also assist in evaluating the vasculature and should be performed [24,32]. A noncontrast phase is typically obtained as part of the CTA and may be helpful in identifying intramural hemorrhage, atherosclerotic calcifications, and to serve as baseline for assessing wall enhancement; however, several studies have shown that obtaining the noncontrast phase may not be required for accurate acute ischemia diagnosis [25,31,33-35]. CT imaging of the abdomen and pelvis also allows accurate evaluation of the entire gastrointestinal and genitourinary tract, helping to exclude most of the other causes of acute and chronic abdominal pain, including cholelithiasis, cholecystitis, pancreatitis, appendicitis, diverticulosis with or without diverticulitis, and nephrolithiasis. Vascular CT findings include arterial stenosis, embolism, thrombosis, arterial dissection, and mesenteric vein thrombosis. Nonvascular CT findings include bowel-wall thickening, hypoperfusion and hypoattenuation, bowel dilatation, bowel-wall hemorrhage, mesenteric fat stranding, pneumatosis intestinalis, and portal venous gas. Quantitative methods of assessing bowel enhancement may also add value in identifying ischemic bowel [36]. Imaging of Mesenteric Ischemia CTA is also preferred in patients with renal insufficiency with GFR under 30 who have suspected acute ischemia as benefits of a fast and accurate diagnosis will generally outweigh risks associated with potential risk of contrast- induced nephropathy [37,38]. | Imaging of Mesenteric Ischemia. A negative or neutral oral contrast, such as low-density barium sulfate or water, has been advocated to distend the small bowel and better evaluate the bowel wall for thickening and enhancement; however this may not be possible in the acute setting [30]. Both arterial and portal venous phases should be included as part of the protocol to assess both arterial and venous patency [25,30,31]. Three-dimensional (3-D) rendering may also assist in evaluating the vasculature and should be performed [24,32]. A noncontrast phase is typically obtained as part of the CTA and may be helpful in identifying intramural hemorrhage, atherosclerotic calcifications, and to serve as baseline for assessing wall enhancement; however, several studies have shown that obtaining the noncontrast phase may not be required for accurate acute ischemia diagnosis [25,31,33-35]. CT imaging of the abdomen and pelvis also allows accurate evaluation of the entire gastrointestinal and genitourinary tract, helping to exclude most of the other causes of acute and chronic abdominal pain, including cholelithiasis, cholecystitis, pancreatitis, appendicitis, diverticulosis with or without diverticulitis, and nephrolithiasis. Vascular CT findings include arterial stenosis, embolism, thrombosis, arterial dissection, and mesenteric vein thrombosis. Nonvascular CT findings include bowel-wall thickening, hypoperfusion and hypoattenuation, bowel dilatation, bowel-wall hemorrhage, mesenteric fat stranding, pneumatosis intestinalis, and portal venous gas. Quantitative methods of assessing bowel enhancement may also add value in identifying ischemic bowel [36]. Imaging of Mesenteric Ischemia CTA is also preferred in patients with renal insufficiency with GFR under 30 who have suspected acute ischemia as benefits of a fast and accurate diagnosis will generally outweigh risks associated with potential risk of contrast- induced nephropathy [37,38]. | 70909 |
acrac_70909_4 | Imaging of Mesenteric Ischemia | Overall, CTA is an accurate technique for acute mesenteric ischemia diagnosis, with reported sensitivity and specificity as high as 93% to 100% and potential to improve patient survival [1,12,15,25,35,39-41]. CT Abdomen and Pelvis CT of the abdomen and pelvis with intravenous (IV) contrast performed during the venous phase has been less well studied compared with CTA in diagnosing mesenteric ischemia. CT with IV contrast can assess nonvascular findings, major arterial lesions, and mesenteric veins; however, the lack of arterial phase may lead to suboptimal evaluation of the mesenteric arteries compared to CTA [25,42]. Schieda et al [42] showed that CT during portal venous phase identified major arterial lesions, although several diagnostic errors occurred when relying on this phase only. Arterial phase influenced care in 19% of patients compared to portal venous phase alone in one study [25]. Because CT with IV contrast is typically performed with oral contrast as well, this additional step may potentially lead to delay in image acquisition and diagnosis. Therefore, CTA is preferred over CT with IV contrast during venous phase as the initial examination when mesenteric ischemia is suspected. There is a lack of relevant literature regarding the use of CT without IV contrast in the evaluation of acute mesenteric ischemia. Nonvascular findings, such as bowel dilation, wall thickening, mesenteric fluid, pneumatosis, and portomesenteric gas, can be identified with a noncontrast CT; however, these tend to be nonspecific or found in more advanced ischemia with a worse prognosis [40,42]. Blachar et al [43] showed that there was worse performance for CT without IV contrast compared to CT with IV contrast, although this was not statistically significant. However, in the same study, the most significant signs of ischemia, arterial filling defects, and decreased bowel wall enhancement, relied on IV contrast, emphasizing the use of contrast when possible [25,31,43]. | Imaging of Mesenteric Ischemia. Overall, CTA is an accurate technique for acute mesenteric ischemia diagnosis, with reported sensitivity and specificity as high as 93% to 100% and potential to improve patient survival [1,12,15,25,35,39-41]. CT Abdomen and Pelvis CT of the abdomen and pelvis with intravenous (IV) contrast performed during the venous phase has been less well studied compared with CTA in diagnosing mesenteric ischemia. CT with IV contrast can assess nonvascular findings, major arterial lesions, and mesenteric veins; however, the lack of arterial phase may lead to suboptimal evaluation of the mesenteric arteries compared to CTA [25,42]. Schieda et al [42] showed that CT during portal venous phase identified major arterial lesions, although several diagnostic errors occurred when relying on this phase only. Arterial phase influenced care in 19% of patients compared to portal venous phase alone in one study [25]. Because CT with IV contrast is typically performed with oral contrast as well, this additional step may potentially lead to delay in image acquisition and diagnosis. Therefore, CTA is preferred over CT with IV contrast during venous phase as the initial examination when mesenteric ischemia is suspected. There is a lack of relevant literature regarding the use of CT without IV contrast in the evaluation of acute mesenteric ischemia. Nonvascular findings, such as bowel dilation, wall thickening, mesenteric fluid, pneumatosis, and portomesenteric gas, can be identified with a noncontrast CT; however, these tend to be nonspecific or found in more advanced ischemia with a worse prognosis [40,42]. Blachar et al [43] showed that there was worse performance for CT without IV contrast compared to CT with IV contrast, although this was not statistically significant. However, in the same study, the most significant signs of ischemia, arterial filling defects, and decreased bowel wall enhancement, relied on IV contrast, emphasizing the use of contrast when possible [25,31,43]. | 70909 |
acrac_70909_5 | Imaging of Mesenteric Ischemia | Similarly to CT with IV contrast, oral contrast administration may delay the examination if it is routinely performed. CT without and with IV contrast is not indicated in the evaluation of suspected acute mesenteric ischemia. MRA Abdomen and Pelvis Magnetic resonance angiography (MRA) of the abdomen and pelvis with IV contrast has high sensitivity and specificity for diagnosing severe stenosis or occlusion at the origins of the celiac axis and SMA [44-47]. However, it has a limited role in diagnosing distal stenosis as well as nonocclusive mesenteric ischemia, and its use may delay therapeutic options in acute settings because it is a long examination. MRA is tailored to depict mesenteric vasculature and less likely to show ischemic findings within the bowel itself compared to CT, such as pneumatosis and portovenous gas; it is also unlikely to provide additional information in the acute setting if portal venous phase CT has already been performed [48]. MRA without contrast can be attempted in some cases; however, evaluation of smaller vessels may be suboptimal [46]. In the past decade with the advances in technology, CTA supplanted conventional angiography as the first-line imaging technique for acute mesenteric ischemia, and angiography transitioned to complementary diagnostic role with an option of endovascular treatment for revascularization candidates [57-62]. Although there is a lack of Level I evidence demonstrating clear benefits of endovascular therapy compared to open surgery in patients with acute mesenteric ischemia, the available data from systematic reviews and case series show that the endovascular approach is becoming more common and is associated with decreased mortality and need for laparotomy [57-62]. Nonetheless, acute mesenteric ischemia is a vascular surgical emergency requiring immediate surgical evaluation and angiography should not be considered in patients with significant hypovolemia or hypotension. | Imaging of Mesenteric Ischemia. Similarly to CT with IV contrast, oral contrast administration may delay the examination if it is routinely performed. CT without and with IV contrast is not indicated in the evaluation of suspected acute mesenteric ischemia. MRA Abdomen and Pelvis Magnetic resonance angiography (MRA) of the abdomen and pelvis with IV contrast has high sensitivity and specificity for diagnosing severe stenosis or occlusion at the origins of the celiac axis and SMA [44-47]. However, it has a limited role in diagnosing distal stenosis as well as nonocclusive mesenteric ischemia, and its use may delay therapeutic options in acute settings because it is a long examination. MRA is tailored to depict mesenteric vasculature and less likely to show ischemic findings within the bowel itself compared to CT, such as pneumatosis and portovenous gas; it is also unlikely to provide additional information in the acute setting if portal venous phase CT has already been performed [48]. MRA without contrast can be attempted in some cases; however, evaluation of smaller vessels may be suboptimal [46]. In the past decade with the advances in technology, CTA supplanted conventional angiography as the first-line imaging technique for acute mesenteric ischemia, and angiography transitioned to complementary diagnostic role with an option of endovascular treatment for revascularization candidates [57-62]. Although there is a lack of Level I evidence demonstrating clear benefits of endovascular therapy compared to open surgery in patients with acute mesenteric ischemia, the available data from systematic reviews and case series show that the endovascular approach is becoming more common and is associated with decreased mortality and need for laparotomy [57-62]. Nonetheless, acute mesenteric ischemia is a vascular surgical emergency requiring immediate surgical evaluation and angiography should not be considered in patients with significant hypovolemia or hypotension. | 70909 |
acrac_70909_6 | Imaging of Mesenteric Ischemia | Urgent bowel reperfusion with the goal of infarction prevention is paramount and requires early diagnosis and involvement of Imaging of Mesenteric Ischemia vascular surgery, interventional radiology, and intensive care unit who need to work collaboratively, guiding resuscitation efforts and future treatment. US Duplex Doppler Abdomen The efficacy of ultrasound (US) in diagnosing acute mesenteric ischemia has been evaluated in many studies. US can demonstrate proximal mesenteric vessel thrombosis via Doppler mode and can be used in detecting proximal superior mesenteric and celiac artery stenosis with high sensitivity and specificity of 85% to 90% [63,64]. US may also reveal focal superior mesenteric or portal venous thrombosis in cases of venous occlusive ischemia [65]. Unfortunately, the presence of overlying bowel gas, obesity, and vascular calcifications are challenges for an adequate sonographic evaluation. In addition, duplex US has a limited role in detecting distal arterial emboli or in diagnosing nonocclusive mesenteric ischemia. Moreover, the length of the examination and the possible pain associated with the applied pressure to the abdomen during imaging may be limiting factors in initial evaluation of patients with suspected acute mesenteric ischemia [12,63,66]. Variant 2: Suspected chronic mesenteric ischemia. Initial Imaging. In the setting of chronic mesenteric ischemia, patients classically present with the clinical triad of postprandial abdominal pain 30 to 60 minutes after food consumption, weight loss, and food avoidance. Nausea and vomiting, postprandial diarrhea, early satiety and signs of malabsorption may also be present [12]. In an elderly patient with an underlying atherosclerosis, history of weight loss, and early satiety, chronic mesenteric ischemia should be strongly considered [28]. As with acute ischemia, clinical evaluation alone is insufficient for making the diagnosis of chronic ischemia, and imaging plays a key role for this purpose [67]. | Imaging of Mesenteric Ischemia. Urgent bowel reperfusion with the goal of infarction prevention is paramount and requires early diagnosis and involvement of Imaging of Mesenteric Ischemia vascular surgery, interventional radiology, and intensive care unit who need to work collaboratively, guiding resuscitation efforts and future treatment. US Duplex Doppler Abdomen The efficacy of ultrasound (US) in diagnosing acute mesenteric ischemia has been evaluated in many studies. US can demonstrate proximal mesenteric vessel thrombosis via Doppler mode and can be used in detecting proximal superior mesenteric and celiac artery stenosis with high sensitivity and specificity of 85% to 90% [63,64]. US may also reveal focal superior mesenteric or portal venous thrombosis in cases of venous occlusive ischemia [65]. Unfortunately, the presence of overlying bowel gas, obesity, and vascular calcifications are challenges for an adequate sonographic evaluation. In addition, duplex US has a limited role in detecting distal arterial emboli or in diagnosing nonocclusive mesenteric ischemia. Moreover, the length of the examination and the possible pain associated with the applied pressure to the abdomen during imaging may be limiting factors in initial evaluation of patients with suspected acute mesenteric ischemia [12,63,66]. Variant 2: Suspected chronic mesenteric ischemia. Initial Imaging. In the setting of chronic mesenteric ischemia, patients classically present with the clinical triad of postprandial abdominal pain 30 to 60 minutes after food consumption, weight loss, and food avoidance. Nausea and vomiting, postprandial diarrhea, early satiety and signs of malabsorption may also be present [12]. In an elderly patient with an underlying atherosclerosis, history of weight loss, and early satiety, chronic mesenteric ischemia should be strongly considered [28]. As with acute ischemia, clinical evaluation alone is insufficient for making the diagnosis of chronic ischemia, and imaging plays a key role for this purpose [67]. | 70909 |
acrac_70909_7 | Imaging of Mesenteric Ischemia | Radiography Abdomen Radiography has little to no role in the diagnosis of chronic mesenteric ischemia because these patients have not yet developed bowel necrosis, and therefore the radiograph will likely be normal or demonstrate nonspecific findings. A negative radiograph also does not exclude the diagnosis of chronic mesenteric ischemia [19,57,68]. CTA Abdomen and Pelvis CTA of the abdomen and pelvis has been shown to provide best accuracy and inter-reader agreement for grading mesenteric vessel stenosis compared to MRA and US, with sensitivity and specificity of 95% to 100% using DSA as a reference standard [29]. Moreover, CTA is an accurate diagnosing tool for detecting median arcuate ligament syndrome as a potential cause of chronic ischemia [7]. CTA can also accurately exclude other causes of chronic abdominal pain. CT Abdomen and Pelvis CT of the abdomen and pelvis with IV contrast performed during the venous phase appears to provide satisfactory evaluation of major vascular pathology, such as atherosclerotic plaques and occlusions, although this has not been well studied [69]. There is a paucity of data regarding performance of CT without IV contrast for suspected chronic mesenteric ischemia. Although able to assess the extent calcified atherosclerotic plaque affects the mesenteric vasculature, CT without IV contrast is limited in its ability to evaluate noncalcified plaque and is therefore likely to underestimate the degree of stenosis. Additionally, calcified atherosclerotic plaque in the mesenteric vasculature is a common incidental finding in the elderly population and cannot be relied upon for accurate diagnosis of chronic mesenteric ischemia [24,26,33]. CT without and with IV contrast is not indicated in the evaluation of suspected chronic mesenteric ischemia. | Imaging of Mesenteric Ischemia. Radiography Abdomen Radiography has little to no role in the diagnosis of chronic mesenteric ischemia because these patients have not yet developed bowel necrosis, and therefore the radiograph will likely be normal or demonstrate nonspecific findings. A negative radiograph also does not exclude the diagnosis of chronic mesenteric ischemia [19,57,68]. CTA Abdomen and Pelvis CTA of the abdomen and pelvis has been shown to provide best accuracy and inter-reader agreement for grading mesenteric vessel stenosis compared to MRA and US, with sensitivity and specificity of 95% to 100% using DSA as a reference standard [29]. Moreover, CTA is an accurate diagnosing tool for detecting median arcuate ligament syndrome as a potential cause of chronic ischemia [7]. CTA can also accurately exclude other causes of chronic abdominal pain. CT Abdomen and Pelvis CT of the abdomen and pelvis with IV contrast performed during the venous phase appears to provide satisfactory evaluation of major vascular pathology, such as atherosclerotic plaques and occlusions, although this has not been well studied [69]. There is a paucity of data regarding performance of CT without IV contrast for suspected chronic mesenteric ischemia. Although able to assess the extent calcified atherosclerotic plaque affects the mesenteric vasculature, CT without IV contrast is limited in its ability to evaluate noncalcified plaque and is therefore likely to underestimate the degree of stenosis. Additionally, calcified atherosclerotic plaque in the mesenteric vasculature is a common incidental finding in the elderly population and cannot be relied upon for accurate diagnosis of chronic mesenteric ischemia [24,26,33]. CT without and with IV contrast is not indicated in the evaluation of suspected chronic mesenteric ischemia. | 70909 |
acrac_69470_0 | Crohn Disease | Introduction/Background Crohn disease (CD) is a chronic inflammatory disorder involving the gastrointestinal tract, typically characterized by episodic flares and times of remission. Over the past several decades, there has been an increasing incidence of this disease [1-3]. Any portion of the gastrointestinal tract or alimentary tract may be involved, but the small bowel alone is affected in about a third of patients, the colon alone in a somewhat higher percentage of patients, and combined involvement of the colon and the small bowel is seen in less than a third of patients [4,5]. Perianal disease is another not uncommon manifestation [6]. Pathologically, CD is characterized by transmural granulomatous inflammation [7]. Although the bowel may return to normal after an acute flare, underlying structural damage progressively occurs over time with recurrent bouts of inflammation, leading to stricture formation, penetrating sinuses or fistulas, or a combination of the two [8]. The diagnosis of CD is based on a combination of clinical, laboratory, endoscopic, histological, and imaging findings [7,9]. No single diagnostic test allows unequivocal diagnosis. The imaging characteristics and distribution of disease provide supportive evidence for the diagnosis of CD. In addition, imaging is complementary to endoscopic techniques such as ileocolonoscopy, which allows diagnosis of disease when endoscopy is negative because of intramural disease without associated mucosal activity or because of a lack of colonic and distal ileal involvement [10]. Disease activity has been traditionally determined by clinical factors including patient symptoms and laboratory tests in which indices, such as Crohns Disease Activity Index, help to determine management. There is growing evidence, however, that active inflammation can exist despite clinical resolution of symptoms [11-13] and that complete mucosal healing represents a better treatment target for long-term outcomes than reliance on clinical symptoms [13]. | Crohn Disease. Introduction/Background Crohn disease (CD) is a chronic inflammatory disorder involving the gastrointestinal tract, typically characterized by episodic flares and times of remission. Over the past several decades, there has been an increasing incidence of this disease [1-3]. Any portion of the gastrointestinal tract or alimentary tract may be involved, but the small bowel alone is affected in about a third of patients, the colon alone in a somewhat higher percentage of patients, and combined involvement of the colon and the small bowel is seen in less than a third of patients [4,5]. Perianal disease is another not uncommon manifestation [6]. Pathologically, CD is characterized by transmural granulomatous inflammation [7]. Although the bowel may return to normal after an acute flare, underlying structural damage progressively occurs over time with recurrent bouts of inflammation, leading to stricture formation, penetrating sinuses or fistulas, or a combination of the two [8]. The diagnosis of CD is based on a combination of clinical, laboratory, endoscopic, histological, and imaging findings [7,9]. No single diagnostic test allows unequivocal diagnosis. The imaging characteristics and distribution of disease provide supportive evidence for the diagnosis of CD. In addition, imaging is complementary to endoscopic techniques such as ileocolonoscopy, which allows diagnosis of disease when endoscopy is negative because of intramural disease without associated mucosal activity or because of a lack of colonic and distal ileal involvement [10]. Disease activity has been traditionally determined by clinical factors including patient symptoms and laboratory tests in which indices, such as Crohns Disease Activity Index, help to determine management. There is growing evidence, however, that active inflammation can exist despite clinical resolution of symptoms [11-13] and that complete mucosal healing represents a better treatment target for long-term outcomes than reliance on clinical symptoms [13]. | 69470 |
acrac_69470_1 | Crohn Disease | In this regard, both endoscopy and imaging are becoming central tools in CD to detect such inflammation [13,14]. They are complementary in nature with differing advantages [9]. Colonoscopy with ileal intubation allows direct visualization of mucosal inflammation and ulceration and the possibility of biopsy. Cross- sectional imaging, such as CT enterography or MR enterography, allows evaluation of disease proximal to the ileum beyond the reach of the colonoscope as well as detection of transmural disease with overlying normal mucosa that may be not apparent at direct optical inspection. aPanel Chair, University of Wisconsin Hospital & Clinics, Madison, Wisconsin. bNewton-Wellesley Hospital, Newton, Massachusetts. cPanel Vice-Chair, University of California San Diego, San Diego, California. dUniversity of Texas Health Science Center at Houston and McGovern Medical School, Houston, Texas; American Gastroenterological Association. eVirginia Tech Carilion School of Medicine, Roanoke, Virginia. fMassachusetts General Hospital, Boston, Massachusetts. gMedstar Georgetown University Hospital, Washington, District of Columbia. hCleveland Clinic, Cleveland, Ohio. iCleveland Clinic, Cleveland, Ohio; American College of Emergency Physicians. jDuke University Medical Center, Durham, North Carolina. kEmory University, Atlanta, Georgia. lPenn State Health, Hershey, Pennsylvania. mUniversity of Alabama at Birmingham, Birmingham, Alabama. nJohns Hopkins Bayview Medical Center, Baltimore, Maryland. oUniversity of California San Francisco, San Francisco, California. pSpecialty Chair, Virginia Commonwealth University Medical Center, Richmond, Virginia. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. | Crohn Disease. In this regard, both endoscopy and imaging are becoming central tools in CD to detect such inflammation [13,14]. They are complementary in nature with differing advantages [9]. Colonoscopy with ileal intubation allows direct visualization of mucosal inflammation and ulceration and the possibility of biopsy. Cross- sectional imaging, such as CT enterography or MR enterography, allows evaluation of disease proximal to the ileum beyond the reach of the colonoscope as well as detection of transmural disease with overlying normal mucosa that may be not apparent at direct optical inspection. aPanel Chair, University of Wisconsin Hospital & Clinics, Madison, Wisconsin. bNewton-Wellesley Hospital, Newton, Massachusetts. cPanel Vice-Chair, University of California San Diego, San Diego, California. dUniversity of Texas Health Science Center at Houston and McGovern Medical School, Houston, Texas; American Gastroenterological Association. eVirginia Tech Carilion School of Medicine, Roanoke, Virginia. fMassachusetts General Hospital, Boston, Massachusetts. gMedstar Georgetown University Hospital, Washington, District of Columbia. hCleveland Clinic, Cleveland, Ohio. iCleveland Clinic, Cleveland, Ohio; American College of Emergency Physicians. jDuke University Medical Center, Durham, North Carolina. kEmory University, Atlanta, Georgia. lPenn State Health, Hershey, Pennsylvania. mUniversity of Alabama at Birmingham, Birmingham, Alabama. nJohns Hopkins Bayview Medical Center, Baltimore, Maryland. oUniversity of California San Francisco, San Francisco, California. pSpecialty Chair, Virginia Commonwealth University Medical Center, Richmond, Virginia. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. | 69470 |
acrac_69470_2 | Crohn Disease | Reprint requests to: [email protected] Crohn Disease which occurs with water, allowing for increased distal luminal distention. If the patient cannot tolerate the oral contrast requirements of the enterography technique, CT can still be performed but with a loss of sensitivity. Although positive oral contrast often obscures the presence of subtle inflammation, it has been shown to improve detection of potential complications related to ongoing CD, including abscess formation, fistula and sinus tract formation, compared with neutral agents [16]. Thus, in some circumstances, positive luminal contrast may be the preferred agent at a standard CT to detect such complications. CT enterography or MR enterography involves oral ingestion by the patient, whereas CT enteroclysis and MR enteroclysis involves placement of a nasoduodenal tube to allow oral contrast infusion directly into the small bowel at a predetermined rate. These procedures are more invasive and may not be well tolerated by acutely ill patients. The technical demands of the enteroclysis protocol related to placement of a nasoduodenal tube and the need for radiologist monitoring throughout the procedure have been negative impediments to widespread use. Bowel distention of the jejunum is typically less at enterography than at enteroclysis but is considered acceptable with good technique [17,18]. CT Enterography CT enterography represents a CT examination with a specialized protocol. Neutral contrast by mouth is given in large amounts over a set time to promote optimal distention of the small bowel [19-21]. Combined with other technical modifications, including thin collimation, multiplanar reconstruction, and intravenous (IV) contrast, this protocol maximizes the technique to depict inflammatory changes in the small bowel related to CD [20,22,23]. It is difficult to precisely determine the test characteristics in CD exactly because of the lack of a true reference standard. | Crohn Disease. Reprint requests to: [email protected] Crohn Disease which occurs with water, allowing for increased distal luminal distention. If the patient cannot tolerate the oral contrast requirements of the enterography technique, CT can still be performed but with a loss of sensitivity. Although positive oral contrast often obscures the presence of subtle inflammation, it has been shown to improve detection of potential complications related to ongoing CD, including abscess formation, fistula and sinus tract formation, compared with neutral agents [16]. Thus, in some circumstances, positive luminal contrast may be the preferred agent at a standard CT to detect such complications. CT enterography or MR enterography involves oral ingestion by the patient, whereas CT enteroclysis and MR enteroclysis involves placement of a nasoduodenal tube to allow oral contrast infusion directly into the small bowel at a predetermined rate. These procedures are more invasive and may not be well tolerated by acutely ill patients. The technical demands of the enteroclysis protocol related to placement of a nasoduodenal tube and the need for radiologist monitoring throughout the procedure have been negative impediments to widespread use. Bowel distention of the jejunum is typically less at enterography than at enteroclysis but is considered acceptable with good technique [17,18]. CT Enterography CT enterography represents a CT examination with a specialized protocol. Neutral contrast by mouth is given in large amounts over a set time to promote optimal distention of the small bowel [19-21]. Combined with other technical modifications, including thin collimation, multiplanar reconstruction, and intravenous (IV) contrast, this protocol maximizes the technique to depict inflammatory changes in the small bowel related to CD [20,22,23]. It is difficult to precisely determine the test characteristics in CD exactly because of the lack of a true reference standard. | 69470 |
acrac_69470_3 | Crohn Disease | However, the overall diagnostic performance for CT enterography is excellent. When an endoscopic standard is utilized, sensitivity for CD ranges from 75% to 90%, with a specificity of >90% [24-27]. Compared with other imaging modalities, CT enterography represents an optimal option for most patients [21,27-31]. The diagnosis of acute inflammation is made through visualization of thickened small bowel with mural stratification as well as extraenteric processes including engorged vasa recti/vasculature and surrounding inflammatory stranding [25,26,32-34]. Because CT enterography is a cross-sectional imaging modality, assessment for alternative diagnoses, as well for the possible complications of CD including obstruction, abscess, and fistula, can be made [28,35-37]. With its intrinsic high spatial resolution and reproducible quality, state-of-the-art CT enterography represents one of the main imaging methods for initial diagnosis of small-bowel CD. At many United States medical centers and practices, a combination of CT enterography and ileocolonoscopy has been advocated as the diagnostic algorithm of choice at initial presentation [38]. Ileocolonoscopy can assess for colonic and distal ileal involvement and permits biopsies. The addition of CT enterography allows for assessment of the entire small bowel, including the distal ileum, and is helpful in establishing a CD diagnosis in cases in which the terminal ileum and colon are not involved or when intramural disease is predominant, which may not be apparent at endoscopy. For this variant in which the patient does not have an established diagnosis for CD and other entities remain in the differential, the cross-sectional/global nature of this CT-based modality allows potential diagnosis of an entity mimicking a CD presentation and adds to the utility of CT enterography. Ultimately, the decision to select CT enterography versus a standard CT abdomen and pelvis examination is dependent on the acuity and severity of presentation. | Crohn Disease. However, the overall diagnostic performance for CT enterography is excellent. When an endoscopic standard is utilized, sensitivity for CD ranges from 75% to 90%, with a specificity of >90% [24-27]. Compared with other imaging modalities, CT enterography represents an optimal option for most patients [21,27-31]. The diagnosis of acute inflammation is made through visualization of thickened small bowel with mural stratification as well as extraenteric processes including engorged vasa recti/vasculature and surrounding inflammatory stranding [25,26,32-34]. Because CT enterography is a cross-sectional imaging modality, assessment for alternative diagnoses, as well for the possible complications of CD including obstruction, abscess, and fistula, can be made [28,35-37]. With its intrinsic high spatial resolution and reproducible quality, state-of-the-art CT enterography represents one of the main imaging methods for initial diagnosis of small-bowel CD. At many United States medical centers and practices, a combination of CT enterography and ileocolonoscopy has been advocated as the diagnostic algorithm of choice at initial presentation [38]. Ileocolonoscopy can assess for colonic and distal ileal involvement and permits biopsies. The addition of CT enterography allows for assessment of the entire small bowel, including the distal ileum, and is helpful in establishing a CD diagnosis in cases in which the terminal ileum and colon are not involved or when intramural disease is predominant, which may not be apparent at endoscopy. For this variant in which the patient does not have an established diagnosis for CD and other entities remain in the differential, the cross-sectional/global nature of this CT-based modality allows potential diagnosis of an entity mimicking a CD presentation and adds to the utility of CT enterography. Ultimately, the decision to select CT enterography versus a standard CT abdomen and pelvis examination is dependent on the acuity and severity of presentation. | 69470 |
acrac_69470_4 | Crohn Disease | For more indolent presentations in which the patient is able to tolerate large volumes of oral contrast, CT enterography is preferred because it is can detect more subtle findings of CD compared with a standard CT with positive oral contrast. In contrast, in the acute presentation in which the patient is severely ill and unable to tolerate the large volume requirements, a standard CT (without or with oral contrast) may be the preferred choice. Presumably, any findings of CD would not be subtle in this situation. Crohn Disease CT Abdomen and Pelvis Standard abdomen and pelvis CT with IV contrast with a routine protocol (ie, without neutral oral contrast enterography technique) can be useful in the initial presentation of a patient with CD without a known prior diagnosis, particularly in the instance of an acutely ill individual who may be unable to tolerate large amounts of oral contrast for an enterography protocol. Standard CT also allows for alternative diagnoses that may mimic CD such as appendicitis in this variant. This adds to the potential utility of this modality for this variant. However, if the patient is able to tolerate the oral contrast requirements of CT enterography, optimizing bowel technique improves examination performance over standard CT and should be preferred. Although standard abdomen and pelvis CT can be done either with or without the administration of IV contrast, it is evident that many of the processes, such as mural enhancement associated with CD require IV contrast for optimal assessment. Without IV contrast, such processes can only be inferred by associated findings, such as wall thickening, which may not occur in mild inflammation. In fact, the importance of contrast can be underscored by the emphasis on determining the optimal timing of imaging following IV contrast administration as opposed to comparisons between IV contrast and noncontrast CT [22]. A prior meta-analysis that evaluated CT performance included studies that were all conducted with IV contrast [25]. | Crohn Disease. For more indolent presentations in which the patient is able to tolerate large volumes of oral contrast, CT enterography is preferred because it is can detect more subtle findings of CD compared with a standard CT with positive oral contrast. In contrast, in the acute presentation in which the patient is severely ill and unable to tolerate the large volume requirements, a standard CT (without or with oral contrast) may be the preferred choice. Presumably, any findings of CD would not be subtle in this situation. Crohn Disease CT Abdomen and Pelvis Standard abdomen and pelvis CT with IV contrast with a routine protocol (ie, without neutral oral contrast enterography technique) can be useful in the initial presentation of a patient with CD without a known prior diagnosis, particularly in the instance of an acutely ill individual who may be unable to tolerate large amounts of oral contrast for an enterography protocol. Standard CT also allows for alternative diagnoses that may mimic CD such as appendicitis in this variant. This adds to the potential utility of this modality for this variant. However, if the patient is able to tolerate the oral contrast requirements of CT enterography, optimizing bowel technique improves examination performance over standard CT and should be preferred. Although standard abdomen and pelvis CT can be done either with or without the administration of IV contrast, it is evident that many of the processes, such as mural enhancement associated with CD require IV contrast for optimal assessment. Without IV contrast, such processes can only be inferred by associated findings, such as wall thickening, which may not occur in mild inflammation. In fact, the importance of contrast can be underscored by the emphasis on determining the optimal timing of imaging following IV contrast administration as opposed to comparisons between IV contrast and noncontrast CT [22]. A prior meta-analysis that evaluated CT performance included studies that were all conducted with IV contrast [25]. | 69470 |
acrac_69470_5 | Crohn Disease | There is a clear consensus that noncontrast CT holds poorer performance compared against a CT with IV contrast. Standard CT abdomen and pelvis with IV contrast can provide evidence of inflammation of an affected gastrointestinal segment. Although there may be less than optimal bowel distention with positive luminal contrast (compared with volume loading techniques) and positive contrast may obscure subtle stratified mural enhancement and more subtle areas of active inflammation, CT with positive luminal contrast can identify wall thickening, luminal narrowing, and adjacent inflammatory changes that may be seen in CD [39]. In addition to assessing for inflammation, standard CT with IV contrast can also evaluate for CD complications, including bowel obstruction, fistula formation, and abscess formation, and positive luminal contrast is preferable to no oral contrast in this scenario. Sensitivities for CT-based evaluation for stenosis/obstruction range from 85% to 94% with very high specificities [40,41]. Sensitivities for abscesses are also very good, ranging from 86% to 100% [27,36]. There is more variable performance for fistula detection with sensitivities ranging from 68% to 100% [27,40,42]. One study showed a very low sensitivity of 20% for enteroenteric fistulas in their series [40]. Thus, in the acute setting, standard CT with IV contrast is a suitable option for assessment. On the other hand, if the patient is relatively well and able to tolerate the oral contrast requirements of CT enterography, the optimized bowel protocol increases sensitivity for more subtle inflammation. CT Enteroclysis CT enteroclysis is a CT-based examination in which a nasoduodenal tube is placed to allow controlled distention of the small bowel. Typically, neutral contrast is continuously infused into the small bowel during CT, and IV contrast is also given. This procedure typically allows for better distention of the small bowel compared with oral ingestion at CT enterography [43,44]. | Crohn Disease. There is a clear consensus that noncontrast CT holds poorer performance compared against a CT with IV contrast. Standard CT abdomen and pelvis with IV contrast can provide evidence of inflammation of an affected gastrointestinal segment. Although there may be less than optimal bowel distention with positive luminal contrast (compared with volume loading techniques) and positive contrast may obscure subtle stratified mural enhancement and more subtle areas of active inflammation, CT with positive luminal contrast can identify wall thickening, luminal narrowing, and adjacent inflammatory changes that may be seen in CD [39]. In addition to assessing for inflammation, standard CT with IV contrast can also evaluate for CD complications, including bowel obstruction, fistula formation, and abscess formation, and positive luminal contrast is preferable to no oral contrast in this scenario. Sensitivities for CT-based evaluation for stenosis/obstruction range from 85% to 94% with very high specificities [40,41]. Sensitivities for abscesses are also very good, ranging from 86% to 100% [27,36]. There is more variable performance for fistula detection with sensitivities ranging from 68% to 100% [27,40,42]. One study showed a very low sensitivity of 20% for enteroenteric fistulas in their series [40]. Thus, in the acute setting, standard CT with IV contrast is a suitable option for assessment. On the other hand, if the patient is relatively well and able to tolerate the oral contrast requirements of CT enterography, the optimized bowel protocol increases sensitivity for more subtle inflammation. CT Enteroclysis CT enteroclysis is a CT-based examination in which a nasoduodenal tube is placed to allow controlled distention of the small bowel. Typically, neutral contrast is continuously infused into the small bowel during CT, and IV contrast is also given. This procedure typically allows for better distention of the small bowel compared with oral ingestion at CT enterography [43,44]. | 69470 |
acrac_69470_6 | Crohn Disease | Because of the active infusion, stenoses are more readily determined [43]. There have been few studies evaluating performance in recent years. Although bowel distention of the jejunum is improved with CT enteroclysis, the distention at CT enterography is considered acceptable [17,18], and CT enterography has been more generally utilized over CT enteroclysis because the procedure is better tolerated by patients. As with all imaging modalities, it is difficult to precisely determine the test characteristics in CD exactly because of the lack of a true reference standard. However, the overall diagnostic performance for CT enteroclysis is excellent (ie, >85% sensitivity, >90% specificity) [45-47], and this examination has been used as a reference standard for other modalities in various studies [41,47]. The diagnosis of acute inflammation is made through visualization of thickened small bowel with mural stratification as well as extraenteric processes, including engorged vasa recti/vascular and surrounding inflammatory stranding [43,44]. Because CT enteroclysis is a cross- sectional imaging modality, assessment for alternative diagnoses as well as for the possible complications of CD, including obstruction, abscess, and fistula, can be made [43]. Although the bowel optimization at CT enteroclysis allows excellent examination performance, equivalent to highest-performing modalities, CT enteroclysis is not typically suitable in the acute setting in which the patient is ill. It is not uncommon that they cannot tolerate the requirements of this somewhat invasive examination. In a scenario in which the CD is a diagnostic consideration among others without a prior established diagnosis of inflammatory bowel disease, the discomfort and risks of duodenal intubation and active contrast infusion often outweighs the increased diagnostic performance gained, arguing against its use in this situation. Crohn Disease | Crohn Disease. Because of the active infusion, stenoses are more readily determined [43]. There have been few studies evaluating performance in recent years. Although bowel distention of the jejunum is improved with CT enteroclysis, the distention at CT enterography is considered acceptable [17,18], and CT enterography has been more generally utilized over CT enteroclysis because the procedure is better tolerated by patients. As with all imaging modalities, it is difficult to precisely determine the test characteristics in CD exactly because of the lack of a true reference standard. However, the overall diagnostic performance for CT enteroclysis is excellent (ie, >85% sensitivity, >90% specificity) [45-47], and this examination has been used as a reference standard for other modalities in various studies [41,47]. The diagnosis of acute inflammation is made through visualization of thickened small bowel with mural stratification as well as extraenteric processes, including engorged vasa recti/vascular and surrounding inflammatory stranding [43,44]. Because CT enteroclysis is a cross- sectional imaging modality, assessment for alternative diagnoses as well as for the possible complications of CD, including obstruction, abscess, and fistula, can be made [43]. Although the bowel optimization at CT enteroclysis allows excellent examination performance, equivalent to highest-performing modalities, CT enteroclysis is not typically suitable in the acute setting in which the patient is ill. It is not uncommon that they cannot tolerate the requirements of this somewhat invasive examination. In a scenario in which the CD is a diagnostic consideration among others without a prior established diagnosis of inflammatory bowel disease, the discomfort and risks of duodenal intubation and active contrast infusion often outweighs the increased diagnostic performance gained, arguing against its use in this situation. Crohn Disease | 69470 |
acrac_69470_7 | Crohn Disease | MR Enteroclysis MR enteroclysis is a MR-based examination in which a nasoduodenal tube is placed to allow controlled distention of the small bowel. Typically, biphasic enteral contrast (low signal on T1 and high signal on T2) is infused over time prior to MRI, and IV contrast is given during the MR examination. The technical demands of this more invasive examination are greater but typically allow for better distention of the small bowel compared with oral ingestion with an enterography technique [48]. There have been few studies evaluating performance of this technique in recent years because it is not a widely utilized examination. Although bowel distention of the jejunum is typically less at enterography than with enteroclysis, distention achieved with enterography is considered acceptable [17] and has been more widely utilized compared with MR enteroclysis. As with all imaging modalities, it is difficult to precisely determine the test characteristics in CD exactly because of the lack of a true reference standard. However, the overall diagnostic performance for MR enteroclysis is excellent and at least equivalent to MR enterography [49]. One comparison study between these two modalities demonstrated statistically better detection of superficial mucosal abnormalities over MR enterography but no difference for stenoses and fistulas [50]. Although the bowel optimization at MR enteroclysis allows excellent examination performance, equivalent to the highest-performing modalities, MR enteroclysis is not typically suitable in the acute setting in which the patient is ill. Often, they cannot tolerate the requirements related to placement of the nasoduodenal tube and active infusion of contrast. In addition, the evaluation for alternative diagnoses mimicking CD may be more difficult or limited. MR Enterography MR enterography combines contrast-enhanced MRI scanning using fast imaging techniques with an enterography protocol to optimize bowel distension [38]. | Crohn Disease. MR Enteroclysis MR enteroclysis is a MR-based examination in which a nasoduodenal tube is placed to allow controlled distention of the small bowel. Typically, biphasic enteral contrast (low signal on T1 and high signal on T2) is infused over time prior to MRI, and IV contrast is given during the MR examination. The technical demands of this more invasive examination are greater but typically allow for better distention of the small bowel compared with oral ingestion with an enterography technique [48]. There have been few studies evaluating performance of this technique in recent years because it is not a widely utilized examination. Although bowel distention of the jejunum is typically less at enterography than with enteroclysis, distention achieved with enterography is considered acceptable [17] and has been more widely utilized compared with MR enteroclysis. As with all imaging modalities, it is difficult to precisely determine the test characteristics in CD exactly because of the lack of a true reference standard. However, the overall diagnostic performance for MR enteroclysis is excellent and at least equivalent to MR enterography [49]. One comparison study between these two modalities demonstrated statistically better detection of superficial mucosal abnormalities over MR enterography but no difference for stenoses and fistulas [50]. Although the bowel optimization at MR enteroclysis allows excellent examination performance, equivalent to the highest-performing modalities, MR enteroclysis is not typically suitable in the acute setting in which the patient is ill. Often, they cannot tolerate the requirements related to placement of the nasoduodenal tube and active infusion of contrast. In addition, the evaluation for alternative diagnoses mimicking CD may be more difficult or limited. MR Enterography MR enterography combines contrast-enhanced MRI scanning using fast imaging techniques with an enterography protocol to optimize bowel distension [38]. | 69470 |
acrac_69470_8 | Crohn Disease | As described with CT enterography, this requires the patient to ingest a large volume of oral contrast in a set time. Additionally, the use of glucagon or prone imaging may help to decrease bowel peristalsis and thus artifact. MR enterography holds excellent test performance characteristics (see below) equivalent to other optimized modalities, such as CT enterography. The ability to diagnose alternative diagnoses may be decreased in cases when a CT-based option may be preferable, depending on the level of patient acuity and ability to hold still. Severely ill patients are less likely to be able to hold still for the duration of MRI examination, leading to increased artifact and poorer image quality. In addition, if ill, the patient may not be able to tolerate the required large volumes of contrast required at MR enterography. MRI Abdomen and Pelvis Standard MRI with a routine protocol (ie, MRI without and with IV contrast and without oral contrast enterography technique) can detect evidence of CD if the patient cannot tolerate large volumes of oral contrast (ie, acutely ill patients). However, the lack of bowel optimization technique decreases evaluation of more subtle findings. One study (n = 100) reported a sensitivity of 50% to 86% and specificity of 93% to 94% for wall thickening [73]. Thus, standard MR may be an option when oral contrast requirements at enterography cannot be tolerated. For CD complications, the diagnostic ability of MRI is similar to standard CT with IV with similar reported sensitivities and specificities in various series [27,40,58,72]. The sensitivity for stenosis/obstruction ranges from 87% to 92% with high specificities; detection performance remains high for abscesses, with sensitivity ranging from 86% to 100%. As with CT, the detection for fistulas is more variable, ranging from 40% to 100%. Because of | Crohn Disease. As described with CT enterography, this requires the patient to ingest a large volume of oral contrast in a set time. Additionally, the use of glucagon or prone imaging may help to decrease bowel peristalsis and thus artifact. MR enterography holds excellent test performance characteristics (see below) equivalent to other optimized modalities, such as CT enterography. The ability to diagnose alternative diagnoses may be decreased in cases when a CT-based option may be preferable, depending on the level of patient acuity and ability to hold still. Severely ill patients are less likely to be able to hold still for the duration of MRI examination, leading to increased artifact and poorer image quality. In addition, if ill, the patient may not be able to tolerate the required large volumes of contrast required at MR enterography. MRI Abdomen and Pelvis Standard MRI with a routine protocol (ie, MRI without and with IV contrast and without oral contrast enterography technique) can detect evidence of CD if the patient cannot tolerate large volumes of oral contrast (ie, acutely ill patients). However, the lack of bowel optimization technique decreases evaluation of more subtle findings. One study (n = 100) reported a sensitivity of 50% to 86% and specificity of 93% to 94% for wall thickening [73]. Thus, standard MR may be an option when oral contrast requirements at enterography cannot be tolerated. For CD complications, the diagnostic ability of MRI is similar to standard CT with IV with similar reported sensitivities and specificities in various series [27,40,58,72]. The sensitivity for stenosis/obstruction ranges from 87% to 92% with high specificities; detection performance remains high for abscesses, with sensitivity ranging from 86% to 100%. As with CT, the detection for fistulas is more variable, ranging from 40% to 100%. Because of | 69470 |
acrac_69470_9 | Crohn Disease | Crohn Disease the superior soft-tissue contrast, perianal disease including fistulation to the perineum is best evaluated at MRI, using a small field of view and focused examination [74-76]. Standard MRI without IV contrast has been investigated because of emerging concerns with IV gadolinium use and potential long-term accumulation in the body and brain. Noncontrast techniques, such as diffusion-weighted imaging (DWI), have been used to evaluate evidence for CD. There is growing literature examining its promise in detecting active disease versus quiescent disease for complication evaluation and disease monitoring, although many of the studies involve DWI in the context of enterography technique [77]. One study without enterography technique [48] reported a sensitivity of 49% to 82% and specificity of 85% to 93% for DWI, although lower specificities have been reported at meta-analysis [78]. Overall, DWI appears to have moderate sensitivity but low specificity leading to increased false positives for disease activity [77]. Thus, the current consensus is that noncontrast only techniques such as DWI can be done but there is likely improved performance with the information gained from post-IV contrast series. Severely ill patients are less likely to be able to hold still for the duration of an MRI examination, leading to increased artifact and poorer image quality. In these instances, other options may be preferable, particularly CT enterography or standard abdomen and pelvic CT. Radiography Abdomen Radiographs of the abdomen are limited in the initial diagnosis for CD. The ability to directly visualize bowel pathology is limited, and evidence for CD is instead inferred indirectly. Radiographs may be useful in severely ill presenting patients to evaluate for the presence of bowel perforation or obstruction. | Crohn Disease. Crohn Disease the superior soft-tissue contrast, perianal disease including fistulation to the perineum is best evaluated at MRI, using a small field of view and focused examination [74-76]. Standard MRI without IV contrast has been investigated because of emerging concerns with IV gadolinium use and potential long-term accumulation in the body and brain. Noncontrast techniques, such as diffusion-weighted imaging (DWI), have been used to evaluate evidence for CD. There is growing literature examining its promise in detecting active disease versus quiescent disease for complication evaluation and disease monitoring, although many of the studies involve DWI in the context of enterography technique [77]. One study without enterography technique [48] reported a sensitivity of 49% to 82% and specificity of 85% to 93% for DWI, although lower specificities have been reported at meta-analysis [78]. Overall, DWI appears to have moderate sensitivity but low specificity leading to increased false positives for disease activity [77]. Thus, the current consensus is that noncontrast only techniques such as DWI can be done but there is likely improved performance with the information gained from post-IV contrast series. Severely ill patients are less likely to be able to hold still for the duration of an MRI examination, leading to increased artifact and poorer image quality. In these instances, other options may be preferable, particularly CT enterography or standard abdomen and pelvic CT. Radiography Abdomen Radiographs of the abdomen are limited in the initial diagnosis for CD. The ability to directly visualize bowel pathology is limited, and evidence for CD is instead inferred indirectly. Radiographs may be useful in severely ill presenting patients to evaluate for the presence of bowel perforation or obstruction. | 69470 |
acrac_69470_10 | Crohn Disease | Fluoroscopy Small-Bowel Follow-Through and Fluoroscopic Enteroclysis Historically, fluoroscopic contrast examinations of the gastrointestinal tract have been the primary imaging methods of choice in the diagnosis of CD. Small-bowel follow-through (SBFT; with or without per oral pneumocolon) and enteroclysis can be used to evaluate the small bowel for evidence of thickening and active disease [50,79]. In addition, internal fistulas can be detected [80], although other extramural complications, such as abscess formation, are only indirectly visualized, which leads to decreased detection [27]. It has become evident; however, with the emergence of specialized cross-sectional imaging modalities, that the performance of contrast fluoroscopy is not as accurate for active disease as compared to these other examinations [18,42,46,81,82]. Both SBFT and enteroclysis are hampered by their 2-D perspective, whereby pathology can be obscured because of overlapping bowel loops [18,82,83]. On the other hand, the real-time assessment for a fixed versus pliable nature of a segment of bowel can provide important ancillary information. Depending on institutional and surgeon preference, there may be a role in delineating the preoperative anatomy for the surgeon, although there has been a marked decline in fluoroscopic use over recent years. In addition, fluoroscopic examinations may not be tolerated in acutely ill patients because of the oral contrast requirements for these procedures. Fluoroscopy Contrast Enema Colonoscopy is the preferred initial examination of the colon in patients suspected of having inflammatory bowel disease primarily involving the colon as opposed to the small bowel [9]. Colonoscopy is superior to the barium enema for the detection of early inflammatory changes and has largely replaced it as the initial diagnostic examination [9]. Particularly in an acutely ill patient, a contrast enema may be technically challenging because of the need for retrograde contrast instillation. Crohn Disease | Crohn Disease. Fluoroscopy Small-Bowel Follow-Through and Fluoroscopic Enteroclysis Historically, fluoroscopic contrast examinations of the gastrointestinal tract have been the primary imaging methods of choice in the diagnosis of CD. Small-bowel follow-through (SBFT; with or without per oral pneumocolon) and enteroclysis can be used to evaluate the small bowel for evidence of thickening and active disease [50,79]. In addition, internal fistulas can be detected [80], although other extramural complications, such as abscess formation, are only indirectly visualized, which leads to decreased detection [27]. It has become evident; however, with the emergence of specialized cross-sectional imaging modalities, that the performance of contrast fluoroscopy is not as accurate for active disease as compared to these other examinations [18,42,46,81,82]. Both SBFT and enteroclysis are hampered by their 2-D perspective, whereby pathology can be obscured because of overlapping bowel loops [18,82,83]. On the other hand, the real-time assessment for a fixed versus pliable nature of a segment of bowel can provide important ancillary information. Depending on institutional and surgeon preference, there may be a role in delineating the preoperative anatomy for the surgeon, although there has been a marked decline in fluoroscopic use over recent years. In addition, fluoroscopic examinations may not be tolerated in acutely ill patients because of the oral contrast requirements for these procedures. Fluoroscopy Contrast Enema Colonoscopy is the preferred initial examination of the colon in patients suspected of having inflammatory bowel disease primarily involving the colon as opposed to the small bowel [9]. Colonoscopy is superior to the barium enema for the detection of early inflammatory changes and has largely replaced it as the initial diagnostic examination [9]. Particularly in an acutely ill patient, a contrast enema may be technically challenging because of the need for retrograde contrast instillation. Crohn Disease | 69470 |
acrac_69470_11 | Crohn Disease | However, patient factors such as obesity and guarding, especially in the acutely ill scenario, may preclude adequate compression with the US probe. In addition, large amounts of shadowing gas may obscure bowel, preventing an optimal examination. Location of bowel involvement affects diagnosis with higher sensitivities for terminal ileal involvement detection as compared with more proximal small bowel disease [87]. False-positive diagnoses of abscesses are more likely at US [97]. The determination for alternative etiologies may also be decreased as compared with CT or MRI. HMPAO WBC Scan Leucoscintigraphy or Tc-99m-hexamethyl propylene amine oxime-labeled white blood cell (Tc-99m HMPAO WBC) scan have demonstrated good sensitivities and specificities for intestinal inflammation in the 79% to 85% and 81% to 98% range, respectively [98]. Proponents contend that leucoscintigraphy is useful in the diagnosis and evaluation of activity of extent of disease [99] with performance results equivalent to cross-sectional imaging [28]. However, the disadvantages of this examination, such as the decreased ability to depict and therefore detect alternative diagnoses and the complicated time-consuming technical aspects (ie, labeling and handling of blood products) have limited its use in initial diagnosis. Furthermore, leucoscintigraphy is limited in alternative diagnoses mimicking CD. FDG-PET/CT Skull Base to Mid-Thigh The addition of metabolic information from PET with the morphologic anatomic imaging of CT or MR shows promise. It may be helpful to better assess the level of active inflammation from fibrosis [100,101]. Studies also show improved assessment in the colon in a murine animal model [102], which points to potential future usefulness because the colon is less well evaluated at both CT enterography and MR enterography. At this point, there are few large-series published clinical studies but small series show promising results [103,104]. Variant 2: Known Crohn disease, suspected acute exacerbation. | Crohn Disease. However, patient factors such as obesity and guarding, especially in the acutely ill scenario, may preclude adequate compression with the US probe. In addition, large amounts of shadowing gas may obscure bowel, preventing an optimal examination. Location of bowel involvement affects diagnosis with higher sensitivities for terminal ileal involvement detection as compared with more proximal small bowel disease [87]. False-positive diagnoses of abscesses are more likely at US [97]. The determination for alternative etiologies may also be decreased as compared with CT or MRI. HMPAO WBC Scan Leucoscintigraphy or Tc-99m-hexamethyl propylene amine oxime-labeled white blood cell (Tc-99m HMPAO WBC) scan have demonstrated good sensitivities and specificities for intestinal inflammation in the 79% to 85% and 81% to 98% range, respectively [98]. Proponents contend that leucoscintigraphy is useful in the diagnosis and evaluation of activity of extent of disease [99] with performance results equivalent to cross-sectional imaging [28]. However, the disadvantages of this examination, such as the decreased ability to depict and therefore detect alternative diagnoses and the complicated time-consuming technical aspects (ie, labeling and handling of blood products) have limited its use in initial diagnosis. Furthermore, leucoscintigraphy is limited in alternative diagnoses mimicking CD. FDG-PET/CT Skull Base to Mid-Thigh The addition of metabolic information from PET with the morphologic anatomic imaging of CT or MR shows promise. It may be helpful to better assess the level of active inflammation from fibrosis [100,101]. Studies also show improved assessment in the colon in a murine animal model [102], which points to potential future usefulness because the colon is less well evaluated at both CT enterography and MR enterography. At this point, there are few large-series published clinical studies but small series show promising results [103,104]. Variant 2: Known Crohn disease, suspected acute exacerbation. | 69470 |
acrac_69470_12 | Crohn Disease | In this clinical variant, there is an established diagnosis of CD. Here, the patient presents with acute worsening of symptoms attributable to known disease. The concern is for an active flare or for the development of a complication of CD (ie, obstruction, abscess, fistula development). The clinical suspicion of an alternative diagnosis mimicking CD is low. CT Abdomen and Pelvis Standard abdomen and pelvis CT with IV contrast with a routine protocol (ie, without oral contrast enterography technique) can be useful in the suspected exacerbation of CD. Although the imaging findings of an acute flare in a known CD patient are typically not subtle (ie, not the situation of subtle mucosal enhancement in a clinically asymptomatic patient undergoing treatment monitoring), optimizing the bowel by enterography technique leads to improved detection of inflammation and should be pursued if the patient can tolerate the oral contrast. On the other hand, CT with positive luminal contrast (without enterography technique) can identify wall thickening, luminal narrowing, and adjacent inflammatory changes that may be seen in CD [19]. In addition, the complications of abscess formation or fistula formation can be detected at standard IV contrast CT in which the positive oral contrast may improve detection of complications. Sensitivities for abscesses are very good, ranging from 86% to 100% [27,36]. There is more variable performance for fistula detection with sensitivities ranging from 68% to 100% [27,40,42]. One study showed a very low sensitivity of 20% for enteroenteric fistulas in their series [40]. Although standard abdomen and pelvis CT can be done either with or without the administration of IV contrast, it is evident that many of the processes seen with an acute flare in CD require IV contrast for optimal assessment. Without IV contrast, such processes can only be inferred by associated findings, such as wall thickening. | Crohn Disease. In this clinical variant, there is an established diagnosis of CD. Here, the patient presents with acute worsening of symptoms attributable to known disease. The concern is for an active flare or for the development of a complication of CD (ie, obstruction, abscess, fistula development). The clinical suspicion of an alternative diagnosis mimicking CD is low. CT Abdomen and Pelvis Standard abdomen and pelvis CT with IV contrast with a routine protocol (ie, without oral contrast enterography technique) can be useful in the suspected exacerbation of CD. Although the imaging findings of an acute flare in a known CD patient are typically not subtle (ie, not the situation of subtle mucosal enhancement in a clinically asymptomatic patient undergoing treatment monitoring), optimizing the bowel by enterography technique leads to improved detection of inflammation and should be pursued if the patient can tolerate the oral contrast. On the other hand, CT with positive luminal contrast (without enterography technique) can identify wall thickening, luminal narrowing, and adjacent inflammatory changes that may be seen in CD [19]. In addition, the complications of abscess formation or fistula formation can be detected at standard IV contrast CT in which the positive oral contrast may improve detection of complications. Sensitivities for abscesses are very good, ranging from 86% to 100% [27,36]. There is more variable performance for fistula detection with sensitivities ranging from 68% to 100% [27,40,42]. One study showed a very low sensitivity of 20% for enteroenteric fistulas in their series [40]. Although standard abdomen and pelvis CT can be done either with or without the administration of IV contrast, it is evident that many of the processes seen with an acute flare in CD require IV contrast for optimal assessment. Without IV contrast, such processes can only be inferred by associated findings, such as wall thickening. | 69470 |
acrac_69470_13 | Crohn Disease | In fact, the importance of contrast can be underscored by the emphasis on determining the optimal timing of imaging following IV contrast administration as opposed to comparisons between IV contrast and noncontrast CT [22]. A prior meta-analysis that evaluated CT performance included studies that were all conducted with IV contrast [25]. There is clear consensus that noncontrast CT holds poorer performance compared against a CT with IV contrast. CT Enteroclysis CT enteroclysis is a CT-based examination in which a nasoduodenal tube is placed to allow controlled distention of the small bowel. Typically, neutral contrast is continuously infused into the small bowel during CT, and IV contrast is also administered. This procedure typically allows for better distention of the small bowel compared with oral ingestion at CT enterography [43,44]. Because of the active infusion, stenoses are more readily determined [43]. Crohn Disease The overall diagnostic performance for CT enteroclysis is excellent (ie, >85% sensitivity, >90% specificity) [45- 47], and this examination has been used as a reference standard for other modalities in various studies [41,47]. However, it is important to remember that detection of subtle evidence for CD is not needed in this clinical variant in which the patient is presenting acutely with a suspected flare or complication. Similar to other CT-based options, the assessment for the possible complications of CD, including obstruction, abscess, and fistula, can be made because of its underlying cross-sectional nature without additional advantage from the dedicated enteroclysis protocol. In this specific variant, CT enteroclysis may be limited because it is dependent on the clinical acuity or severity of presentation. With a significant acute flare or complication, the patient would poorly tolerate CT enteroclysis because of the marked demands on the patient related to the placement of the nasoduodenal tube and need for active infusion of oral contrast. | Crohn Disease. In fact, the importance of contrast can be underscored by the emphasis on determining the optimal timing of imaging following IV contrast administration as opposed to comparisons between IV contrast and noncontrast CT [22]. A prior meta-analysis that evaluated CT performance included studies that were all conducted with IV contrast [25]. There is clear consensus that noncontrast CT holds poorer performance compared against a CT with IV contrast. CT Enteroclysis CT enteroclysis is a CT-based examination in which a nasoduodenal tube is placed to allow controlled distention of the small bowel. Typically, neutral contrast is continuously infused into the small bowel during CT, and IV contrast is also administered. This procedure typically allows for better distention of the small bowel compared with oral ingestion at CT enterography [43,44]. Because of the active infusion, stenoses are more readily determined [43]. Crohn Disease The overall diagnostic performance for CT enteroclysis is excellent (ie, >85% sensitivity, >90% specificity) [45- 47], and this examination has been used as a reference standard for other modalities in various studies [41,47]. However, it is important to remember that detection of subtle evidence for CD is not needed in this clinical variant in which the patient is presenting acutely with a suspected flare or complication. Similar to other CT-based options, the assessment for the possible complications of CD, including obstruction, abscess, and fistula, can be made because of its underlying cross-sectional nature without additional advantage from the dedicated enteroclysis protocol. In this specific variant, CT enteroclysis may be limited because it is dependent on the clinical acuity or severity of presentation. With a significant acute flare or complication, the patient would poorly tolerate CT enteroclysis because of the marked demands on the patient related to the placement of the nasoduodenal tube and need for active infusion of oral contrast. | 69470 |
acrac_69470_14 | Crohn Disease | Here, the risks outweigh the added benefits of optimized bowel visualization, and this imaging choice should be avoided when acutely ill. If, however, the patient is relatively asymptomatic, CT enteroclysis may be an appropriate option with excellent diagnostic performance. CT Enterography CT enterography represents a CT examination with a specialized protocol. Neutral contrast by mouth is given in large amounts over a set time period to promote optimal distention of the small bowel [19-21]. Combined with other technical modifications, including thin collimation, multiplanar reconstruction, and IV contrast, this protocol maximizes the technique to depict inflammatory changes in the small bowel related to CD [20,22,23]. CT enterography is well suited to evaluate a potential acute flare or complication of CD. However, if the patient cannot tolerate the contrast requirements of the enterography technique, standard CT may be an option (although less sensitive, the findings of an acute flare are likely not subtle if the patient is acutely ill and unable to tolerate the contrast volume of CT enterography). The overall diagnostic performance for CT enterography is excellent. When an endoscopic standard is utilized, sensitivity for CD ranges from 75% to 90%, with a specificity of >90% [24-27]. The diagnosis of acute inflammation is made through visualization of thickened small bowel with mural stratification, as well as extraenteric processes that include engorged vasa recti/vasculature and surrounding inflammatory stranding [25,26,32-34]. Because CT enterography is a cross-sectional imaging modality, assessment for the possible complications of CD, including obstruction, abscess, and fistula, can be made similar to the ability of standard CT abdomen and pelvis [28,35-37]. Ultimately, the decision to select CT enterography versus a standard CT abdomen and pelvis is dependent on the ability to tolerate the oral contrast requirements of CT enterography. | Crohn Disease. Here, the risks outweigh the added benefits of optimized bowel visualization, and this imaging choice should be avoided when acutely ill. If, however, the patient is relatively asymptomatic, CT enteroclysis may be an appropriate option with excellent diagnostic performance. CT Enterography CT enterography represents a CT examination with a specialized protocol. Neutral contrast by mouth is given in large amounts over a set time period to promote optimal distention of the small bowel [19-21]. Combined with other technical modifications, including thin collimation, multiplanar reconstruction, and IV contrast, this protocol maximizes the technique to depict inflammatory changes in the small bowel related to CD [20,22,23]. CT enterography is well suited to evaluate a potential acute flare or complication of CD. However, if the patient cannot tolerate the contrast requirements of the enterography technique, standard CT may be an option (although less sensitive, the findings of an acute flare are likely not subtle if the patient is acutely ill and unable to tolerate the contrast volume of CT enterography). The overall diagnostic performance for CT enterography is excellent. When an endoscopic standard is utilized, sensitivity for CD ranges from 75% to 90%, with a specificity of >90% [24-27]. The diagnosis of acute inflammation is made through visualization of thickened small bowel with mural stratification, as well as extraenteric processes that include engorged vasa recti/vasculature and surrounding inflammatory stranding [25,26,32-34]. Because CT enterography is a cross-sectional imaging modality, assessment for the possible complications of CD, including obstruction, abscess, and fistula, can be made similar to the ability of standard CT abdomen and pelvis [28,35-37]. Ultimately, the decision to select CT enterography versus a standard CT abdomen and pelvis is dependent on the ability to tolerate the oral contrast requirements of CT enterography. | 69470 |
acrac_69470_15 | Crohn Disease | CT enterography is more sensitive for bowel changes related to CD than standard CT given the oral contrast optimization. However, the findings of CD in an acute flare are often not subtle and can be seen at standard CT. In addition, the complications including abscess or fistula formation may be easier seen at standard CT with positive oral contrast. MR Enteroclysis MR enteroclysis is a MR-based examination in which a nasoduodenal tube is placed to allow controlled distention of the small bowel. Typically, biphasic enteral contrast (low signal on T1 and high signal on T2) is infused, and IV contrast is given. There have been few studies evaluating performance in recent years. The overall diagnostic performance for MR enteroclysis is excellent and at least equivalent to MR enterography [49]. One comparison study between these two modalities demonstrated statistically better detection of superficial mucosal abnormalities over MR enterography but no difference for stenoses and fistulas [50]. In this specific variant, MR enteroclysis may be limited dependent on the clinical acuity or severity of presentation. With a significant acute flare or complication, the patient would poorly tolerate MR enteroclysis because of the marked demands on the patient related to the placement of the nasoduodenal tube and need for active infusion of oral contrast. Here, the risks outweigh the added benefits of optimized bowel visualization, and this imaging choice should be avoided when acutely ill. In addition, patients are likely unable to hold still, leading to increased artifact and poorer image quality. If, however, the patient is relatively asymptomatic, MR enteroclysis may be an appropriate option with excellent diagnostic performance. MR Enterography MR enterography combines contrast-enhanced MRI scanning using fast imaging techniques with an enterography protocol to optimize bowel distension [38]. | Crohn Disease. CT enterography is more sensitive for bowel changes related to CD than standard CT given the oral contrast optimization. However, the findings of CD in an acute flare are often not subtle and can be seen at standard CT. In addition, the complications including abscess or fistula formation may be easier seen at standard CT with positive oral contrast. MR Enteroclysis MR enteroclysis is a MR-based examination in which a nasoduodenal tube is placed to allow controlled distention of the small bowel. Typically, biphasic enteral contrast (low signal on T1 and high signal on T2) is infused, and IV contrast is given. There have been few studies evaluating performance in recent years. The overall diagnostic performance for MR enteroclysis is excellent and at least equivalent to MR enterography [49]. One comparison study between these two modalities demonstrated statistically better detection of superficial mucosal abnormalities over MR enterography but no difference for stenoses and fistulas [50]. In this specific variant, MR enteroclysis may be limited dependent on the clinical acuity or severity of presentation. With a significant acute flare or complication, the patient would poorly tolerate MR enteroclysis because of the marked demands on the patient related to the placement of the nasoduodenal tube and need for active infusion of oral contrast. Here, the risks outweigh the added benefits of optimized bowel visualization, and this imaging choice should be avoided when acutely ill. In addition, patients are likely unable to hold still, leading to increased artifact and poorer image quality. If, however, the patient is relatively asymptomatic, MR enteroclysis may be an appropriate option with excellent diagnostic performance. MR Enterography MR enterography combines contrast-enhanced MRI scanning using fast imaging techniques with an enterography protocol to optimize bowel distension [38]. | 69470 |
acrac_69470_16 | Crohn Disease | As described with CT enterography, this requires the patient to ingest a large volume of oral contrast in a set time period. Additionally, the use of glucagon or prone imaging may help to Crohn Disease decrease bowel peristalsis and thus artifact. MR enterography holds excellent test performance characteristics (see below) equivalent to other optimized modalities, such as CT enterography. The performance of MR enterography for CD is very good. Rates of sensitivity and specificity are 77% to 82% and 80% to 100%, respectively [24,66,67]; MR enterography can accurately display bowel-wall changes in CD [51-54]. Characteristic bowel-wall changes suggesting active inflammation include bowel-wall thickening, high T2 mural signal, mural hyper enhancement with mural stratification, and hyperemic vasa recta [55-64]. MR cine imaging is potentially useful, allowing for assessment of decreased bowel motility in the affected segments with CD [65]. Besides inflammation, MRI can detect complications for CD that include obstruction, abscess, or fistula. Test performance characteristics for complications are similar to CT enterography [27,28,35,40,68,69]. Overall, MRI is more prone to respiratory and bowel-motion artifact, despite the use of glucagon, which may lead to suboptimal examinations and more difficult interpretations. MRI Abdomen and Pelvis Standard MRI with a routine protocol (ie, MRI without and with IV contrast and without oral contrast enterography technique) can detect evidence of CD if the patient cannot tolerate large volumes of oral contrast. However, the lack of bowel optimization decreases evaluation of inflammation compared with MR enterography with optimized bowel technique. One study (n = 100) reported a sensitivity of 50% to 86% and specificity of 93% to 94% for wall thickening [73]. For CD complications, the diagnostic ability of MRI is similar to its CT counterpart with similar reported sensitivities and specificities in various series [27,40,58,72]. | Crohn Disease. As described with CT enterography, this requires the patient to ingest a large volume of oral contrast in a set time period. Additionally, the use of glucagon or prone imaging may help to Crohn Disease decrease bowel peristalsis and thus artifact. MR enterography holds excellent test performance characteristics (see below) equivalent to other optimized modalities, such as CT enterography. The performance of MR enterography for CD is very good. Rates of sensitivity and specificity are 77% to 82% and 80% to 100%, respectively [24,66,67]; MR enterography can accurately display bowel-wall changes in CD [51-54]. Characteristic bowel-wall changes suggesting active inflammation include bowel-wall thickening, high T2 mural signal, mural hyper enhancement with mural stratification, and hyperemic vasa recta [55-64]. MR cine imaging is potentially useful, allowing for assessment of decreased bowel motility in the affected segments with CD [65]. Besides inflammation, MRI can detect complications for CD that include obstruction, abscess, or fistula. Test performance characteristics for complications are similar to CT enterography [27,28,35,40,68,69]. Overall, MRI is more prone to respiratory and bowel-motion artifact, despite the use of glucagon, which may lead to suboptimal examinations and more difficult interpretations. MRI Abdomen and Pelvis Standard MRI with a routine protocol (ie, MRI without and with IV contrast and without oral contrast enterography technique) can detect evidence of CD if the patient cannot tolerate large volumes of oral contrast. However, the lack of bowel optimization decreases evaluation of inflammation compared with MR enterography with optimized bowel technique. One study (n = 100) reported a sensitivity of 50% to 86% and specificity of 93% to 94% for wall thickening [73]. For CD complications, the diagnostic ability of MRI is similar to its CT counterpart with similar reported sensitivities and specificities in various series [27,40,58,72]. | 69470 |
acrac_69470_17 | Crohn Disease | The sensitivity for stenosis/obstruction ranges from 87% to 92% with high specificities; detection performance remains high for abscesses, with sensitivity ranging from 86% to 100%. As with CT, the detection for fistulas is more variable, ranging from 40% to 100%. Because of the superior soft-tissue contrast, perianal disease, including fistulation to the perineum, is best evaluated with MRI, using a small field of view, focused examination [74-76]. Standard MRI without IV contrast has been investigated because of emerging concerns with IV gadolinium use and potential long-term accumulation in the body and brain. Noncontrast techniques such as DWI have been used to evaluate evidence for CD. There is growing literature examining its promise in detecting active disease versus quiescent disease, for complication evaluation, and disease monitoring, although many of the studies involve DWI in the context of enterography technique [77]. One study without enterography technique [48] reported a sensitivity of 49% to 82% and specificity of 85% to 93% for DWI, although lower specificities have been reported at meta- analysis [78] Overall, DWI appears to have moderate sensitivity but low specificity, leading to increased false positives for disease activity [77]. Thus, the current consensus is that noncontrast-only techniques such as DWI can be done, but there is likely improved performance with the information gained from post-IV contrast series. In this specific variant, MR may be limited. Acutely ill patients are less likely to be able to hold still for the duration of an MRI examination, leading to increased artifact and poorer image quality. In these instances, other options may be preferable, particularly CT enterography or standard abdomen and pelvic CT. However, patient factors such as obesity and guarding may not allow adequate compression with the US probe or large amounts of shadowing gas may obscure bowel, preventing an optimal examination. | Crohn Disease. The sensitivity for stenosis/obstruction ranges from 87% to 92% with high specificities; detection performance remains high for abscesses, with sensitivity ranging from 86% to 100%. As with CT, the detection for fistulas is more variable, ranging from 40% to 100%. Because of the superior soft-tissue contrast, perianal disease, including fistulation to the perineum, is best evaluated with MRI, using a small field of view, focused examination [74-76]. Standard MRI without IV contrast has been investigated because of emerging concerns with IV gadolinium use and potential long-term accumulation in the body and brain. Noncontrast techniques such as DWI have been used to evaluate evidence for CD. There is growing literature examining its promise in detecting active disease versus quiescent disease, for complication evaluation, and disease monitoring, although many of the studies involve DWI in the context of enterography technique [77]. One study without enterography technique [48] reported a sensitivity of 49% to 82% and specificity of 85% to 93% for DWI, although lower specificities have been reported at meta- analysis [78] Overall, DWI appears to have moderate sensitivity but low specificity, leading to increased false positives for disease activity [77]. Thus, the current consensus is that noncontrast-only techniques such as DWI can be done, but there is likely improved performance with the information gained from post-IV contrast series. In this specific variant, MR may be limited. Acutely ill patients are less likely to be able to hold still for the duration of an MRI examination, leading to increased artifact and poorer image quality. In these instances, other options may be preferable, particularly CT enterography or standard abdomen and pelvic CT. However, patient factors such as obesity and guarding may not allow adequate compression with the US probe or large amounts of shadowing gas may obscure bowel, preventing an optimal examination. | 69470 |
acrac_69470_18 | Crohn Disease | Location also affects diagnosis in which higher sensitivities for terminal ileal involvement are seen compared with more proximal small bowel [87]. False-positive diagnoses of abscesses are more likely at US [97]. Radiography Abdomen Radiographs of the abdomen are limited in the evaluation of an acute flare or complication of CD. The ability to directly visualize bowel pathology is limited, and evidence for CD is instead inferred indirectly. There is little role for radiographs if the patient is not acutely ill. Radiographs may be useful in severely ill presenting patients for presence of bowel perforation or evidence for obstruction. Crohn Disease Fluoroscopy Small-Bowel Follow-Through and Fluoroscopic Enteroclysis Historically, fluoroscopic contrast examinations of the gastrointestinal tract have been the primary imaging methods of choice in the evaluation of CD. SBFT (with or without per oral pneumocolon) and enteroclysis can be used to evaluate the small bowel for evidence of thickening and active disease [50,79]. In addition, internal fistulas can be detected [80], although other extramural complications, such as abscess formation are only indirectly visualized, which leads to decreased detection [27]. It has become evident; however, with the emergence of specialized cross- sectional imaging modalities, that the performance of contrast fluoroscopy is not as accurate for active disease compared with these other examinations [18,42,46,81,82]. Both SBFT and enteroclysis are hampered by their 2-D perspective, whereby pathology can be obscured because of overlapping bowel loops [18,82,83]. On the other hand, the real-time assessment for a fixed versus pliable nature of a segment of bowel can provide important ancillary information. Depending on institutional and surgeon preference, there may be a role in delineating the preoperative anatomy for the surgeon, although there has been a marked decline in fluoroscopic use over recent years. | Crohn Disease. Location also affects diagnosis in which higher sensitivities for terminal ileal involvement are seen compared with more proximal small bowel [87]. False-positive diagnoses of abscesses are more likely at US [97]. Radiography Abdomen Radiographs of the abdomen are limited in the evaluation of an acute flare or complication of CD. The ability to directly visualize bowel pathology is limited, and evidence for CD is instead inferred indirectly. There is little role for radiographs if the patient is not acutely ill. Radiographs may be useful in severely ill presenting patients for presence of bowel perforation or evidence for obstruction. Crohn Disease Fluoroscopy Small-Bowel Follow-Through and Fluoroscopic Enteroclysis Historically, fluoroscopic contrast examinations of the gastrointestinal tract have been the primary imaging methods of choice in the evaluation of CD. SBFT (with or without per oral pneumocolon) and enteroclysis can be used to evaluate the small bowel for evidence of thickening and active disease [50,79]. In addition, internal fistulas can be detected [80], although other extramural complications, such as abscess formation are only indirectly visualized, which leads to decreased detection [27]. It has become evident; however, with the emergence of specialized cross- sectional imaging modalities, that the performance of contrast fluoroscopy is not as accurate for active disease compared with these other examinations [18,42,46,81,82]. Both SBFT and enteroclysis are hampered by their 2-D perspective, whereby pathology can be obscured because of overlapping bowel loops [18,82,83]. On the other hand, the real-time assessment for a fixed versus pliable nature of a segment of bowel can provide important ancillary information. Depending on institutional and surgeon preference, there may be a role in delineating the preoperative anatomy for the surgeon, although there has been a marked decline in fluoroscopic use over recent years. | 69470 |
acrac_69470_19 | Crohn Disease | Fluoroscopy Contrast Enema Colonoscopy is the preferred examination of the colon in patients suspected of having inflammatory bowel disease [9]. It is superior to the barium enema for the detection of early inflammatory changes and has largely replaced it as the initial diagnostic examination [9]. Although contrast enemas can detect fistulas to other organs and sinus tracts, it is poor for abscess determination given its non-cross-sectional nature. HMPAO WBC Scan Leucoscintigraphy, or Tc-99m-HMPAO WBC scan, have demonstrated good sensitivities and specificities for intestinal inflammation in the 79% to 85% and 81% to 98% range, respectively [98]. Proponents contend that leucoscintigraphy is useful in the diagnosis and evaluation of activity and extent of disease [99] with performance results equivalent to cross-sectional imaging [28]. However, the disadvantages of this examination, such as the decreased ability to depict and therefore detect alternative diagnoses and the complicated time-consuming technical aspects (ie, labeling and handling of blood products), have limited its use in evaluation. FDG-PET/CT Skull Base to Mid-Thigh The addition of metabolic information from PET with the morphologic anatomic imaging of CT or MR shows promise. It may be helpful to better assess the level of active inflammation from fibrosis [100,101]. Studies also show improved assessment in the colon in a murine animal model [102], which points to potential future usefulness because the colon is less well evaluated with both CT enterography and MR enterography. At this point, there are few large-series published clinical studies, but small series show promising results [103,104]. Variant 3: Known Crohn disease, disease surveillance; monitoring therapy. In this clinical scenario, the purpose of the imaging evaluation is to determine the presence or absence of disease activity in a relatively well CD patient (ie, mildly symptomatic to asymptomatic) in order to help determine medical management. | Crohn Disease. Fluoroscopy Contrast Enema Colonoscopy is the preferred examination of the colon in patients suspected of having inflammatory bowel disease [9]. It is superior to the barium enema for the detection of early inflammatory changes and has largely replaced it as the initial diagnostic examination [9]. Although contrast enemas can detect fistulas to other organs and sinus tracts, it is poor for abscess determination given its non-cross-sectional nature. HMPAO WBC Scan Leucoscintigraphy, or Tc-99m-HMPAO WBC scan, have demonstrated good sensitivities and specificities for intestinal inflammation in the 79% to 85% and 81% to 98% range, respectively [98]. Proponents contend that leucoscintigraphy is useful in the diagnosis and evaluation of activity and extent of disease [99] with performance results equivalent to cross-sectional imaging [28]. However, the disadvantages of this examination, such as the decreased ability to depict and therefore detect alternative diagnoses and the complicated time-consuming technical aspects (ie, labeling and handling of blood products), have limited its use in evaluation. FDG-PET/CT Skull Base to Mid-Thigh The addition of metabolic information from PET with the morphologic anatomic imaging of CT or MR shows promise. It may be helpful to better assess the level of active inflammation from fibrosis [100,101]. Studies also show improved assessment in the colon in a murine animal model [102], which points to potential future usefulness because the colon is less well evaluated with both CT enterography and MR enterography. At this point, there are few large-series published clinical studies, but small series show promising results [103,104]. Variant 3: Known Crohn disease, disease surveillance; monitoring therapy. In this clinical scenario, the purpose of the imaging evaluation is to determine the presence or absence of disease activity in a relatively well CD patient (ie, mildly symptomatic to asymptomatic) in order to help determine medical management. | 69470 |
acrac_69470_20 | Crohn Disease | This is important because promoting situations of complete mucosal healing has been associated with sustained clinical remission, reduced hospitalization rates, and decreased need for surgery [12,13,105]. As with endoscopy, imaging may better direct treatment based on objective findings because it is known that subjective symptomatology and other clinical parameters have shown poor correlation with disease activity [106]. Secondly, when CD strictures are detected, imaging can help determine whether the narrowing is predominantly due to active inflammation or due to fibrosis. This distinction is critical because the former responds to medical interventions, whereas the latter would be better treated surgically. Because of the cost and significant complications of agents such as infliximab, empiric treatment with these agents to make this distinction (ie, does treatment improve the stenosis) is less attractive. CT Abdomen and Pelvis Standard abdomen and pelvis CT with IV contrast with a routine protocol (ie, without oral contrast enterography technique) can detect evidence for active CD. CT with positive luminal contrast can identify wall thickening, luminal narrowing, and adjacent inflammatory changes that may be seen in CD [39]. However, mucosal enhancement is obscured and subtle enhancement may be missed without the bowel optimization present with enterography technique. The decreased performance compared against other modalities with optimized bowel protocol would argue against its use in this clinical variant in which the patient is relatively well and able to tolerate the increased oral contrast volumes. Standard abdomen and pelvis CT without IV contrast is further hampered when evidence of increased vascularity seen with IV contrast use is not available. Crohn Disease CT Enteroclysis CT enteroclysis is a CT-based examination in which a nasoduodenal tube is placed to allow controlled distention of the small bowel. Typically, neutral contrast is infused and IV contrast given. | Crohn Disease. This is important because promoting situations of complete mucosal healing has been associated with sustained clinical remission, reduced hospitalization rates, and decreased need for surgery [12,13,105]. As with endoscopy, imaging may better direct treatment based on objective findings because it is known that subjective symptomatology and other clinical parameters have shown poor correlation with disease activity [106]. Secondly, when CD strictures are detected, imaging can help determine whether the narrowing is predominantly due to active inflammation or due to fibrosis. This distinction is critical because the former responds to medical interventions, whereas the latter would be better treated surgically. Because of the cost and significant complications of agents such as infliximab, empiric treatment with these agents to make this distinction (ie, does treatment improve the stenosis) is less attractive. CT Abdomen and Pelvis Standard abdomen and pelvis CT with IV contrast with a routine protocol (ie, without oral contrast enterography technique) can detect evidence for active CD. CT with positive luminal contrast can identify wall thickening, luminal narrowing, and adjacent inflammatory changes that may be seen in CD [39]. However, mucosal enhancement is obscured and subtle enhancement may be missed without the bowel optimization present with enterography technique. The decreased performance compared against other modalities with optimized bowel protocol would argue against its use in this clinical variant in which the patient is relatively well and able to tolerate the increased oral contrast volumes. Standard abdomen and pelvis CT without IV contrast is further hampered when evidence of increased vascularity seen with IV contrast use is not available. Crohn Disease CT Enteroclysis CT enteroclysis is a CT-based examination in which a nasoduodenal tube is placed to allow controlled distention of the small bowel. Typically, neutral contrast is infused and IV contrast given. | 69470 |
acrac_69470_21 | Crohn Disease | Because of the active infusion, stenoses are more easily determined [43]. There have been few studies evaluating performance in recent years. The overall diagnostic performance for CT enteroclysis is excellent (ie, >85% sensitivity, >90% specificity) [45-47], and this examination has been used as a reference standard for other modalities in various studies [41,47]. The diagnosis of acute inflammation is made through visualization of thickened small bowel with mural stratification as well as extraenteric processes, including engorged vasa recti/vasculature and surrounding inflammatory stranding [43,44]. Similar to CT enterography, the ability to detect even mild inflammation makes it useful in monitoring therapy. CT enteroclysis has been shown to be helpful in assessing the status of disease in CD patients post resection at the anastomosis [107]. However, the determination between active disease and fibrosis in a stricture remains difficult based on enhancement characteristics only [108]. Because CT enteroclysis is a cross- sectional imaging modality, assessment for alternative diagnoses as well for the possible complications of CD including obstruction, abscess, and fistula can be made [43]. Although CT enteroclysis represents one of the modalities with highest disease detection capabilities, the invasive nature with nasoduodenal tube insertion and active infusion of contrast may make it less favorable from a patient perspective, unless a mild stricture without definite proximal dilation is the clinical question and active distention is needed to confirm this stricture [9]. In addition, the need for repeated examinations over time makes this a less attractive choice in this clinical variant. CT Enterography CT enterography represents a CT examination with a specialized protocol. Neutral contrast by mouth is given in large amounts over a set time period to promote optimal distention of the small bowel [19-21]. | Crohn Disease. Because of the active infusion, stenoses are more easily determined [43]. There have been few studies evaluating performance in recent years. The overall diagnostic performance for CT enteroclysis is excellent (ie, >85% sensitivity, >90% specificity) [45-47], and this examination has been used as a reference standard for other modalities in various studies [41,47]. The diagnosis of acute inflammation is made through visualization of thickened small bowel with mural stratification as well as extraenteric processes, including engorged vasa recti/vasculature and surrounding inflammatory stranding [43,44]. Similar to CT enterography, the ability to detect even mild inflammation makes it useful in monitoring therapy. CT enteroclysis has been shown to be helpful in assessing the status of disease in CD patients post resection at the anastomosis [107]. However, the determination between active disease and fibrosis in a stricture remains difficult based on enhancement characteristics only [108]. Because CT enteroclysis is a cross- sectional imaging modality, assessment for alternative diagnoses as well for the possible complications of CD including obstruction, abscess, and fistula can be made [43]. Although CT enteroclysis represents one of the modalities with highest disease detection capabilities, the invasive nature with nasoduodenal tube insertion and active infusion of contrast may make it less favorable from a patient perspective, unless a mild stricture without definite proximal dilation is the clinical question and active distention is needed to confirm this stricture [9]. In addition, the need for repeated examinations over time makes this a less attractive choice in this clinical variant. CT Enterography CT enterography represents a CT examination with a specialized protocol. Neutral contrast by mouth is given in large amounts over a set time period to promote optimal distention of the small bowel [19-21]. | 69470 |
acrac_69470_22 | Crohn Disease | Combined with other modifications, including thin collimation, multiplanar reconstruction, and IV contrast, this protocol maximizes the technique to depict inflammatory changes in the small bowel related to CD [20,22,23]. Although the diagnostic performance is excellent (see below), the need for repeated examinations over time makes this a less attractive choice in this clinical variant. The overall diagnostic performance for CT enterography is excellent. When an endoscopic standard is utilized, sensitivity for CD ranges from 75% to 90%, with a specificity of >90% [24-27]. The diagnosis of acute inflammation is made through visualization of thickened small bowel with mural stratification as well as extraenteric processes including engorged vasa recti/vasculature and surrounding inflammatory stranding [25,26,32-34]. Because of an excellent performance profile, CT enterography is able to assess for mucosal healing similar to MR enterography to help guide therapy [109]. One series (n = 63) demonstrated that CT enterography was able to detect wall changes, and influenced the treatment of CD patients [110]. However, regarding strictures, CT enterography has been considered poor in its ability to distinguish between active and fibrotic contributions to the stricture based on the presence or absence of above-mentioned findings (ie, mural hyper enhancement, thickening, engorged vasa recta, surrounding soft tissue thickening, etc) [108]. MR Enteroclysis MR enteroclysis is a MR-based examination in which a nasoduodenal tube is placed to allow controlled distention of the small bowel. Typically, biphasic enteral contrast (low signal on T1 and high signal on T2) is infused, and IV contrast is given. There have been few studies evaluating performance in recent years. The overall diagnostic performance for MR enteroclysis is excellent and at least equivalent to MR enterography [49]. | Crohn Disease. Combined with other modifications, including thin collimation, multiplanar reconstruction, and IV contrast, this protocol maximizes the technique to depict inflammatory changes in the small bowel related to CD [20,22,23]. Although the diagnostic performance is excellent (see below), the need for repeated examinations over time makes this a less attractive choice in this clinical variant. The overall diagnostic performance for CT enterography is excellent. When an endoscopic standard is utilized, sensitivity for CD ranges from 75% to 90%, with a specificity of >90% [24-27]. The diagnosis of acute inflammation is made through visualization of thickened small bowel with mural stratification as well as extraenteric processes including engorged vasa recti/vasculature and surrounding inflammatory stranding [25,26,32-34]. Because of an excellent performance profile, CT enterography is able to assess for mucosal healing similar to MR enterography to help guide therapy [109]. One series (n = 63) demonstrated that CT enterography was able to detect wall changes, and influenced the treatment of CD patients [110]. However, regarding strictures, CT enterography has been considered poor in its ability to distinguish between active and fibrotic contributions to the stricture based on the presence or absence of above-mentioned findings (ie, mural hyper enhancement, thickening, engorged vasa recta, surrounding soft tissue thickening, etc) [108]. MR Enteroclysis MR enteroclysis is a MR-based examination in which a nasoduodenal tube is placed to allow controlled distention of the small bowel. Typically, biphasic enteral contrast (low signal on T1 and high signal on T2) is infused, and IV contrast is given. There have been few studies evaluating performance in recent years. The overall diagnostic performance for MR enteroclysis is excellent and at least equivalent to MR enterography [49]. | 69470 |
acrac_69470_23 | Crohn Disease | One comparison study between these two modalities demonstrated statistically better detection of superficial mucosal abnormalities over MR enterography but no difference for stenoses and fistulas [50]. In this specific variant, MR enteroclysis theoretically holds the same advantages as outlined for MR enterography because the difference between the two is related to active distention via the nasoduodenal tube at MR enteroclysis versus distention from oral ingestion at MR enterography. Thus, the ability to evaluate mucosal healing as well as assessment of strictures for active disease versus fibrosis as documented at MR enterography should be equivalent at MR enteroclysis [48]. However, the invasive nature with nasoduodenal tube insertion and active infusion of contrast may make it less favorable from a patient perspective, unless a mild stricture without proximal dilation is the clinical question and active distention is needed to confirm this stricture [9]. MR Enterography MR enterography combines contrast-enhanced MRI scanning using fast imaging techniques with an enterography protocol to optimize bowel distension [38]. Similar to the case of CT enterography, this bowel optimization Crohn Disease technique requires the patient to ingest a large volume of oral contrast in a set time period. Additionally, the use of glucagon or prone imaging may help to decrease bowel peristalsis and thus artifact. MR enterography represents an ideal modality for repeated use to monitor therapy given its excellent test characteristics. Given the relatively well status of the patient, they are often able to hold still, and quality examinations are more likely to be consistently obtained. The performance of MR enterography for CD is very good. Rates of sensitivity and specificity are 77% to 82% and 80% to 100%, respectively [24,66,67]; MR enterography can accurately display bowel-wall changes in CD [51-54]. | Crohn Disease. One comparison study between these two modalities demonstrated statistically better detection of superficial mucosal abnormalities over MR enterography but no difference for stenoses and fistulas [50]. In this specific variant, MR enteroclysis theoretically holds the same advantages as outlined for MR enterography because the difference between the two is related to active distention via the nasoduodenal tube at MR enteroclysis versus distention from oral ingestion at MR enterography. Thus, the ability to evaluate mucosal healing as well as assessment of strictures for active disease versus fibrosis as documented at MR enterography should be equivalent at MR enteroclysis [48]. However, the invasive nature with nasoduodenal tube insertion and active infusion of contrast may make it less favorable from a patient perspective, unless a mild stricture without proximal dilation is the clinical question and active distention is needed to confirm this stricture [9]. MR Enterography MR enterography combines contrast-enhanced MRI scanning using fast imaging techniques with an enterography protocol to optimize bowel distension [38]. Similar to the case of CT enterography, this bowel optimization Crohn Disease technique requires the patient to ingest a large volume of oral contrast in a set time period. Additionally, the use of glucagon or prone imaging may help to decrease bowel peristalsis and thus artifact. MR enterography represents an ideal modality for repeated use to monitor therapy given its excellent test characteristics. Given the relatively well status of the patient, they are often able to hold still, and quality examinations are more likely to be consistently obtained. The performance of MR enterography for CD is very good. Rates of sensitivity and specificity are 77% to 82% and 80% to 100%, respectively [24,66,67]; MR enterography can accurately display bowel-wall changes in CD [51-54]. | 69470 |
acrac_69470_24 | Crohn Disease | Characteristic bowel-wall changes suggesting active inflammation include bowel-wall thickening, high T2 mural signal, mural hyper enhancement with mural stratification, and hyperemic vasa recta [55-64]. MR cine imaging is potentially useful, allowing for assessment of decreased bowel motility in the affected segments with CD [65]. Besides inflammation, MRI can detect complications for CD including obstruction, abscess, or fistula. Test performance characteristics for complications are similar to CT enterography [27,28,35,40,68,69]. MR enterography has been shown to correlate with response to therapy and mucosal healing [111,112]. One prospective multicenter study (n = 48) showed 90% accuracy of ulcer healing determination at MR enterography, utilizing ileocolonoscopy as the reference standard [113]. In addition, MR is able to utilize natural tissue contrast at T2W imaging to help in the determination between active inflammation and fibrosis, which is not possible with CT-based modalities. DWI, magnetization transfer imaging, and cine sequences at MR enterography can also be helpful. [111]. MR enterography without IV contrast has been investigated because of emerging concerns with IV gadolinium use and potential long-term accumulation in the body and brain. Noncontrast techniques such as DWI have been used to evaluate evidence for CD. There is growing literature examining its promise in detecting active disease versus quiescent disease for complication evaluation and disease monitoring [77]. Overall, DWI appears to have moderate sensitivity but low specificity, leading to increased false positives for disease activity [77]. Thus, the current consensus is that noncontrast only techniques such as DWI can be done but there is likely improved performance with the information gained from post IV contrast series. | Crohn Disease. Characteristic bowel-wall changes suggesting active inflammation include bowel-wall thickening, high T2 mural signal, mural hyper enhancement with mural stratification, and hyperemic vasa recta [55-64]. MR cine imaging is potentially useful, allowing for assessment of decreased bowel motility in the affected segments with CD [65]. Besides inflammation, MRI can detect complications for CD including obstruction, abscess, or fistula. Test performance characteristics for complications are similar to CT enterography [27,28,35,40,68,69]. MR enterography has been shown to correlate with response to therapy and mucosal healing [111,112]. One prospective multicenter study (n = 48) showed 90% accuracy of ulcer healing determination at MR enterography, utilizing ileocolonoscopy as the reference standard [113]. In addition, MR is able to utilize natural tissue contrast at T2W imaging to help in the determination between active inflammation and fibrosis, which is not possible with CT-based modalities. DWI, magnetization transfer imaging, and cine sequences at MR enterography can also be helpful. [111]. MR enterography without IV contrast has been investigated because of emerging concerns with IV gadolinium use and potential long-term accumulation in the body and brain. Noncontrast techniques such as DWI have been used to evaluate evidence for CD. There is growing literature examining its promise in detecting active disease versus quiescent disease for complication evaluation and disease monitoring [77]. Overall, DWI appears to have moderate sensitivity but low specificity, leading to increased false positives for disease activity [77]. Thus, the current consensus is that noncontrast only techniques such as DWI can be done but there is likely improved performance with the information gained from post IV contrast series. | 69470 |
acrac_69470_25 | Crohn Disease | MRI Abdomen and Pelvis Standard MRI with a routine protocol (ie, without and with IV contrast and without oral contrast enterography technique) can detect evidence of CD if the patient cannot tolerate large volumes of oral contrast. However, the lack of bowel optimization decreases evaluation of inflammation. Thus, the key question of quiescent disease versus low levels of continuing inflammation central to this variant is not answered to the same confidence as with MR enterography (with optimized bowel technique). One study (n = 100) reported a sensitivity of 50% to 86% and specificity of 93% to 94% for wall thickening [73]. The literature on mucosal healing and MR has centered on MR enterography as opposed to standard MR without enterography protocol. MR enterography has been shown to correlate with response to therapy and mucosal healing [111,112]. One prospective multicenter study (n = 48) showed 90% accuracy of ulcer healing determination at MR enterography, utilizing ileocolonoscopy as the reference standard [113]. In this specific clinical scenario, the patient is typically able to tolerate enterography technique, and consequently, bowel optimization should be undertaken as opposed to standard MRI for this situation. For CD complications, the diagnostic ability of MRI is similar to its CT counterpart with similar reported sensitivities and specificities in various series [27,40,58,72]. The sensitivity for stenosis/obstruction ranges from 87% to 92% with high specificities; detection performance remains high for abscesses, with sensitivity ranging from 86% to 100%. As with CT, the detection for fistulas is more variable, ranging from 40% to 100%. Because of the superior soft-tissue contrast, perianal disease including fistulation to the perineum is best evaluated at MRI, using a small field-of-view, focused examination [74-76]. Standard MRI without IV contrast has been investigated because of emerging concerns with IV gadolinium use and potential long-term accumulation in the body and brain. | Crohn Disease. MRI Abdomen and Pelvis Standard MRI with a routine protocol (ie, without and with IV contrast and without oral contrast enterography technique) can detect evidence of CD if the patient cannot tolerate large volumes of oral contrast. However, the lack of bowel optimization decreases evaluation of inflammation. Thus, the key question of quiescent disease versus low levels of continuing inflammation central to this variant is not answered to the same confidence as with MR enterography (with optimized bowel technique). One study (n = 100) reported a sensitivity of 50% to 86% and specificity of 93% to 94% for wall thickening [73]. The literature on mucosal healing and MR has centered on MR enterography as opposed to standard MR without enterography protocol. MR enterography has been shown to correlate with response to therapy and mucosal healing [111,112]. One prospective multicenter study (n = 48) showed 90% accuracy of ulcer healing determination at MR enterography, utilizing ileocolonoscopy as the reference standard [113]. In this specific clinical scenario, the patient is typically able to tolerate enterography technique, and consequently, bowel optimization should be undertaken as opposed to standard MRI for this situation. For CD complications, the diagnostic ability of MRI is similar to its CT counterpart with similar reported sensitivities and specificities in various series [27,40,58,72]. The sensitivity for stenosis/obstruction ranges from 87% to 92% with high specificities; detection performance remains high for abscesses, with sensitivity ranging from 86% to 100%. As with CT, the detection for fistulas is more variable, ranging from 40% to 100%. Because of the superior soft-tissue contrast, perianal disease including fistulation to the perineum is best evaluated at MRI, using a small field-of-view, focused examination [74-76]. Standard MRI without IV contrast has been investigated because of emerging concerns with IV gadolinium use and potential long-term accumulation in the body and brain. | 69470 |
acrac_69470_26 | Crohn Disease | Noncontrast techniques such as DWI have been used to evaluate evidence for CD. There is growing literature examining its promise in detecting active disease versus quiescent disease for complication evaluation and disease monitoring, although many of the studies involve DWI in the context of enterography technique [77]. One study without enterography technique [48] reported a sensitivity of 49% to 82% and specificity of 85% to 93% for DWI, although lower specificities have been reported at meta- analysis [78]. Overall, DWI appears to have moderate sensitivity but low specificity, leading to increased false positives for disease activity [77]. Thus, the current consensus is that noncontrast only techniques such as DWI can Crohn Disease be done, but there is likely improved performance with the information gained from post IV contrast series. This reason, as well as the lack of a bowel distention optimization protocol, makes standard MRI without IV contrast less useful in this clinical variant. US Abdomen and Pelvis Transabdominal US can be effective option in CD [84,85]. However, in this variant, it may not be optimal given that areas of the abdomen may not be assessed because of shadowing bowel. However, there is emerging literature that US may be useful in therapy monitoring of CD patients [114,115]. In addition, contrast-enhanced US may be helpful in distinguishing between inflammatory and fibrotic disease [95]. Patient factors such as obesity and guarding may not allow adequate compression with the US probe or large amounts of shadowing gas may obscure bowel, preventing an optimal examination. Location also affects diagnosis in which higher sensitivities for terminal ileal involvement are seen compared to more proximal small bowel [87]. False positive diagnoses of abscesses are more likely at US [97]. Radiography Abdomen Radiographs of the abdomen are limited in the evaluation for CD. | Crohn Disease. Noncontrast techniques such as DWI have been used to evaluate evidence for CD. There is growing literature examining its promise in detecting active disease versus quiescent disease for complication evaluation and disease monitoring, although many of the studies involve DWI in the context of enterography technique [77]. One study without enterography technique [48] reported a sensitivity of 49% to 82% and specificity of 85% to 93% for DWI, although lower specificities have been reported at meta- analysis [78]. Overall, DWI appears to have moderate sensitivity but low specificity, leading to increased false positives for disease activity [77]. Thus, the current consensus is that noncontrast only techniques such as DWI can Crohn Disease be done, but there is likely improved performance with the information gained from post IV contrast series. This reason, as well as the lack of a bowel distention optimization protocol, makes standard MRI without IV contrast less useful in this clinical variant. US Abdomen and Pelvis Transabdominal US can be effective option in CD [84,85]. However, in this variant, it may not be optimal given that areas of the abdomen may not be assessed because of shadowing bowel. However, there is emerging literature that US may be useful in therapy monitoring of CD patients [114,115]. In addition, contrast-enhanced US may be helpful in distinguishing between inflammatory and fibrotic disease [95]. Patient factors such as obesity and guarding may not allow adequate compression with the US probe or large amounts of shadowing gas may obscure bowel, preventing an optimal examination. Location also affects diagnosis in which higher sensitivities for terminal ileal involvement are seen compared to more proximal small bowel [87]. False positive diagnoses of abscesses are more likely at US [97]. Radiography Abdomen Radiographs of the abdomen are limited in the evaluation for CD. | 69470 |
acrac_69470_27 | Crohn Disease | The ability to directly visualize bowel pathology is limited, and evidence for CD is instead inferred indirectly. There is little role for radiography in this clinical variant. Fluoroscopy Small-Bowel Follow-Through Historically, fluoroscopic contrast examinations of the gastrointestinal tract have been the primary imaging methods of choice in the evaluation of CD. SBFT (with or without per oral pneumocolon) and enteroclysis can be used to evaluate the small bowel for evidence of thickening and active disease [50,79]. In addition, internal fistulas can be detected [80], although other extramural complications such as abscess formation are only indirectly visualized, which lead to decreased detection [27]. It has become evident; however, with the emergence of specialized cross sectional imaging modalities, that the performance of contrast fluoroscopy is not as accurate for active disease as compared with these other examinations [18,42,46,81,82]. Thus, there is little evidence to support its use in this specific clinical variant in which the inflammation may be very subtle. Both SBFT and enteroclysis are hampered by their 2-D perspective, whereby pathology can be obscured because of overlapping bowel loops [18,82,83]. On the other hand, the real-time assessment for a fixed versus pliable nature of a segment of bowel can provide important ancillary information. Dependent on institutional and surgeon preference, there may be a role in delineating the preoperative anatomy for the surgeon, although there has been a marked decline in fluoroscopic use over recent years. Fluoroscopy Contrast Enema Colonoscopy is the preferred initial examination of the colon in patients suspected of having inflammatory bowel disease [9]. It is superior to the barium enema for the detection of early inflammatory changes and has largely replaced it as the diagnostic examination [9]. | Crohn Disease. The ability to directly visualize bowel pathology is limited, and evidence for CD is instead inferred indirectly. There is little role for radiography in this clinical variant. Fluoroscopy Small-Bowel Follow-Through Historically, fluoroscopic contrast examinations of the gastrointestinal tract have been the primary imaging methods of choice in the evaluation of CD. SBFT (with or without per oral pneumocolon) and enteroclysis can be used to evaluate the small bowel for evidence of thickening and active disease [50,79]. In addition, internal fistulas can be detected [80], although other extramural complications such as abscess formation are only indirectly visualized, which lead to decreased detection [27]. It has become evident; however, with the emergence of specialized cross sectional imaging modalities, that the performance of contrast fluoroscopy is not as accurate for active disease as compared with these other examinations [18,42,46,81,82]. Thus, there is little evidence to support its use in this specific clinical variant in which the inflammation may be very subtle. Both SBFT and enteroclysis are hampered by their 2-D perspective, whereby pathology can be obscured because of overlapping bowel loops [18,82,83]. On the other hand, the real-time assessment for a fixed versus pliable nature of a segment of bowel can provide important ancillary information. Dependent on institutional and surgeon preference, there may be a role in delineating the preoperative anatomy for the surgeon, although there has been a marked decline in fluoroscopic use over recent years. Fluoroscopy Contrast Enema Colonoscopy is the preferred initial examination of the colon in patients suspected of having inflammatory bowel disease [9]. It is superior to the barium enema for the detection of early inflammatory changes and has largely replaced it as the diagnostic examination [9]. | 69470 |
acrac_3111292_0 | Dementia | Introduction/Background Degenerative disease of the central nervous system is a growing public health concern. The prevalence of dementia, one of the leading degenerative conditions, is expected to quadruple by 2050 [1]. Other degenerative diseases may affect the extrapyramidal system and the motor system. Dementia is characterized by a significant loss of function in multiple cognitive domains without affecting the general level of arousal. Several forms are now recognized, including Alzheimer disease (AD), frontotemporal dementia (FTD), Lewy bodies disease, vascular dementia (VaD), and mixed dementias [2]. Although the causes of most dementias remain elusive, genetic research has opened many frontiers to understanding the pathophysiology of heretofore enigmas such as AD [1,3]. Additionally, infectious, autoimmune, and toxic etiologies have become increasingly more appreciated as causes of cognitive decline. Trauma with brain injury may also be associated with premature dementia. AD dementia is part of a continuum of clinical and biological phenomena. The workgroup emphasizes that AD dementia is fundamentally a clinical diagnosis. To make a diagnosis of AD dementia with biomarker support, the core clinical diagnosis of AD dementia must first be satisfied. In these recommendations, the term mild cognitive impairment (MCI) that is due to AD is used to refer to the symptomatic predementia phase of AD [5]. Similar to AD dementia, MCI that is due to AD cannot be currently diagnosed by a laboratory test but requires the judgment of a clinician. In addition, similar to AD dementia, etiologies in addition to AD pathophysiological processes may coexist in an individual that meets the criteria for MCI that is due to AD but in whom the AD pathophysiological process is the main cause of the cognitive dysfunction. | Dementia. Introduction/Background Degenerative disease of the central nervous system is a growing public health concern. The prevalence of dementia, one of the leading degenerative conditions, is expected to quadruple by 2050 [1]. Other degenerative diseases may affect the extrapyramidal system and the motor system. Dementia is characterized by a significant loss of function in multiple cognitive domains without affecting the general level of arousal. Several forms are now recognized, including Alzheimer disease (AD), frontotemporal dementia (FTD), Lewy bodies disease, vascular dementia (VaD), and mixed dementias [2]. Although the causes of most dementias remain elusive, genetic research has opened many frontiers to understanding the pathophysiology of heretofore enigmas such as AD [1,3]. Additionally, infectious, autoimmune, and toxic etiologies have become increasingly more appreciated as causes of cognitive decline. Trauma with brain injury may also be associated with premature dementia. AD dementia is part of a continuum of clinical and biological phenomena. The workgroup emphasizes that AD dementia is fundamentally a clinical diagnosis. To make a diagnosis of AD dementia with biomarker support, the core clinical diagnosis of AD dementia must first be satisfied. In these recommendations, the term mild cognitive impairment (MCI) that is due to AD is used to refer to the symptomatic predementia phase of AD [5]. Similar to AD dementia, MCI that is due to AD cannot be currently diagnosed by a laboratory test but requires the judgment of a clinician. In addition, similar to AD dementia, etiologies in addition to AD pathophysiological processes may coexist in an individual that meets the criteria for MCI that is due to AD but in whom the AD pathophysiological process is the main cause of the cognitive dysfunction. | 3111292 |
acrac_3111292_1 | Dementia | The stage of preclinical AD precedes MCI and encompasses the spectrum of presymptomatic autosomal dominant mutation carriers, asymptomatic biomarker-positive older individuals at risk for progression to MCI that is due to AD and AD dementia, as well as biomarker-positive individuals who have demonstrated a subtle decline from their own baseline that exceeds the expected in typical aging but would not yet meet criteria for MCI [6]. aColumbia University Medical Center, New York, New York. bUT Southwestern Medical Center, Dallas, Texas. cResearch Author, Emory University, Atlanta, Georgia. dPanel Chair, Montefiore Medical Center, Bronx, New York. eUC San Diego Health, San Diego, California. fOttawa Hospital Research Institute and the Department of Radiology, The University of Ottawa, Ottawa, Ontario, Canada; Canadian Association of Radiologists. gMCVH-Virginia Commonwealth University, Richmond, Virginia; Neurosurgery Expert. hUniversity of Kansas Medical Center, Kansas City, Kansas. iEinstein Healthcare Network, Philadelphia, Pennsylvania. jUniversity of California San Diego Medical Center, San Diego, California. kOregon Health & Science University, Portland, Oregon. lUniversity of North Carolina School of Medicine, Chapel Hill, North Carolina; American Academy of Neurology. mSheppard Pratt Health System, Towson, Maryland; American Psychiatric Association. nNorthwestern University Feinberg School of Medicine, Chicago, Illinois; Neurosurgery Expert. oWalter Reed National Military Medical Center, Bethesda, Maryland. pColumbia University Medical Center, New York, New York. qSpecialty Chair, Atlanta VA Health Care System and Emory University, Atlanta, Georgia. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. | Dementia. The stage of preclinical AD precedes MCI and encompasses the spectrum of presymptomatic autosomal dominant mutation carriers, asymptomatic biomarker-positive older individuals at risk for progression to MCI that is due to AD and AD dementia, as well as biomarker-positive individuals who have demonstrated a subtle decline from their own baseline that exceeds the expected in typical aging but would not yet meet criteria for MCI [6]. aColumbia University Medical Center, New York, New York. bUT Southwestern Medical Center, Dallas, Texas. cResearch Author, Emory University, Atlanta, Georgia. dPanel Chair, Montefiore Medical Center, Bronx, New York. eUC San Diego Health, San Diego, California. fOttawa Hospital Research Institute and the Department of Radiology, The University of Ottawa, Ottawa, Ontario, Canada; Canadian Association of Radiologists. gMCVH-Virginia Commonwealth University, Richmond, Virginia; Neurosurgery Expert. hUniversity of Kansas Medical Center, Kansas City, Kansas. iEinstein Healthcare Network, Philadelphia, Pennsylvania. jUniversity of California San Diego Medical Center, San Diego, California. kOregon Health & Science University, Portland, Oregon. lUniversity of North Carolina School of Medicine, Chapel Hill, North Carolina; American Academy of Neurology. mSheppard Pratt Health System, Towson, Maryland; American Psychiatric Association. nNorthwestern University Feinberg School of Medicine, Chicago, Illinois; Neurosurgery Expert. oWalter Reed National Military Medical Center, Bethesda, Maryland. pColumbia University Medical Center, New York, New York. qSpecialty Chair, Atlanta VA Health Care System and Emory University, Atlanta, Georgia. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. | 3111292 |
acrac_3111292_2 | Dementia | Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] In persons who meet the core clinical criteria for probable AD dementia, biomarker evidence may increase the certainty that the basis of the clinical dementia syndrome is the AD pathophysiological process. The recommendations of the working group did not advocate the use of AD biomarker tests for routine diagnostic purposes [4]. However, this opinion was refined in the 2014 position paper from the International Working Group- 2, which proposed that the diagnosis of AD required an appropriate clinical AD phenotype (typical or atypical) and a pathophysiological marker consistent with AD pathology (including increased tracer retention on amyloid PET), moving amyloid PET into the diagnostic realm. The biomarkers of downstream neuronal injury, such as volumetric MRI and FDG-PET, were considered agents to measure or monitor the course of disease but not for initial diagnosis [8]. The primary role of neuroimaging in the workup of patients with probable or possible AD has typically been to exclude other significant intracranial abnormalities. In general, the imaging findings in structural studies such as MRI are nonspecific but may suggest other forms of dementia. The American Academy of Neurology (AAN) has recommended that the routine use of structural neuroimaging, such as a noncontrast CT or MRI examination, may assist with the diagnosis of dementia [9]. Advanced methods, such as volumetric MRI, amyloid PET, and FDG- PET, are not routinely used in community or general practices for the diagnosis or differentiation of forms of dementia [10-12]. CT Head Noncontrast CT head is used as a primary examination to exclude treatable lesions like a mass or subdural hematoma [9]. | Dementia. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] In persons who meet the core clinical criteria for probable AD dementia, biomarker evidence may increase the certainty that the basis of the clinical dementia syndrome is the AD pathophysiological process. The recommendations of the working group did not advocate the use of AD biomarker tests for routine diagnostic purposes [4]. However, this opinion was refined in the 2014 position paper from the International Working Group- 2, which proposed that the diagnosis of AD required an appropriate clinical AD phenotype (typical or atypical) and a pathophysiological marker consistent with AD pathology (including increased tracer retention on amyloid PET), moving amyloid PET into the diagnostic realm. The biomarkers of downstream neuronal injury, such as volumetric MRI and FDG-PET, were considered agents to measure or monitor the course of disease but not for initial diagnosis [8]. The primary role of neuroimaging in the workup of patients with probable or possible AD has typically been to exclude other significant intracranial abnormalities. In general, the imaging findings in structural studies such as MRI are nonspecific but may suggest other forms of dementia. The American Academy of Neurology (AAN) has recommended that the routine use of structural neuroimaging, such as a noncontrast CT or MRI examination, may assist with the diagnosis of dementia [9]. Advanced methods, such as volumetric MRI, amyloid PET, and FDG- PET, are not routinely used in community or general practices for the diagnosis or differentiation of forms of dementia [10-12]. CT Head Noncontrast CT head is used as a primary examination to exclude treatable lesions like a mass or subdural hematoma [9]. | 3111292 |
acrac_3111292_3 | Dementia | Although not as accurate as MRI, CT also permits detection of hippocampal atrophy in AD patients [13] but is not recommended as first-line imaging for this purpose because MRI provides higher resolution images. Contrast- enhanced CT head is not recommended because the examination is mainly used to rule out other pathologies that do not typically require contrast for detection. Similarly, dual-phase CT head is not indicated in the evaluation of AD. However, amyloid PET may be positive in cognitively normal subjects who do not develop AD and in patients with other forms of non-AD dementia [22]. Although a negative amyloid PET scan likely means a low probability of AD, the patient may still harbor a non-AD neurodegenerative condition. The Amyloid Imaging Task Force, the Society of Nuclear Medicine and Molecular Imaging, and the Alzheimer's Association has proposed guidelines for the use of amyloid PET [23,24]. The taskforce suggests that amyloid PET may be useful and appropriate in patients with a cognitive complaint and confirmed impairment when AD is in the differential but the diagnosis is uncertain after evaluation by a dementia expert and the knowledge of the presence or absence of amyloid deposition is felt to add to patient care (although currently no treatment can slow AD progression, and the presence of amyloid cannot be sufficiently predictive in many cases). The taskforce cites specific appropriate use criteria in which amyloid PET might be useful: persistent or progressive unexplained MCI, possible AD (unclear clinical presentation, atypical clinical course or etiologically mixed presentation, and Dementia A CMS-convened Medicare Evidence Development and Coverage Advisory Committee that met in 2013 concluded there was low to intermediate confidence that amyloid PET would significantly contribute to the care of these patients. However, in its national coverage decision, CMS concluded that amyloid PET would be covered under a coverage with evidence development program [25]. | Dementia. Although not as accurate as MRI, CT also permits detection of hippocampal atrophy in AD patients [13] but is not recommended as first-line imaging for this purpose because MRI provides higher resolution images. Contrast- enhanced CT head is not recommended because the examination is mainly used to rule out other pathologies that do not typically require contrast for detection. Similarly, dual-phase CT head is not indicated in the evaluation of AD. However, amyloid PET may be positive in cognitively normal subjects who do not develop AD and in patients with other forms of non-AD dementia [22]. Although a negative amyloid PET scan likely means a low probability of AD, the patient may still harbor a non-AD neurodegenerative condition. The Amyloid Imaging Task Force, the Society of Nuclear Medicine and Molecular Imaging, and the Alzheimer's Association has proposed guidelines for the use of amyloid PET [23,24]. The taskforce suggests that amyloid PET may be useful and appropriate in patients with a cognitive complaint and confirmed impairment when AD is in the differential but the diagnosis is uncertain after evaluation by a dementia expert and the knowledge of the presence or absence of amyloid deposition is felt to add to patient care (although currently no treatment can slow AD progression, and the presence of amyloid cannot be sufficiently predictive in many cases). The taskforce cites specific appropriate use criteria in which amyloid PET might be useful: persistent or progressive unexplained MCI, possible AD (unclear clinical presentation, atypical clinical course or etiologically mixed presentation, and Dementia A CMS-convened Medicare Evidence Development and Coverage Advisory Committee that met in 2013 concluded there was low to intermediate confidence that amyloid PET would significantly contribute to the care of these patients. However, in its national coverage decision, CMS concluded that amyloid PET would be covered under a coverage with evidence development program [25]. | 3111292 |
acrac_3111292_4 | Dementia | According to the practice parameter for amyloid brain PET that was developed collaboratively by the ACR and the American Society for Neuroradiology (ASNR) [26], indications for amyloid PET mirror those of the amyloid imaging taskforce as above. FDG-PET/CT Brain PET imaging in dementia can be divided into metabolic PET, which uses FDG as a marker for metabolism, and amyloid PET, which uses agents that bind to amyloid deposits within the brain. FDG-PET imaging has been shown to provide greater diagnostic accuracy when compared with clinical evaluations without functional neuroimaging [27]. Hypometabolism on FDG-PET is thought to be related to decreased synaptic activity and is a biomarker of neurodegeneration or neuronal injury [12]. FDG-PET shows characteristic reductions of regional glucose metabolic rates in patients with probable and definite AD in the parietal, temporal, and posterior cingulate regions [28]. FDG- PET accurately discriminates AD patients from normal subjects with a sensitivity of 96% and specificity of 100% [28]. CMS has made FDG-PET available to Medicare recipients to assist with the diagnosis of dementia in the appropriate clinical setting (eg, to distinguish AD from FTD) in recognition of this usefulness [27]. A practice parameter for FDG-PET/CT for patients with cognitive decline has been developed collaboratively by the ACR-ASNR [26]. The qualifications and responsibilities of the personnel conducting the study and the standardized patient preparation, positioning, and protocol are also outlined in this document. An important detail to be emphasized is that the study should be performed at the request of physicians knowledgeable in clinical diagnosis and management of dementia and under circumstances in which the results of the examination are likely to impact patient care [26]. | Dementia. According to the practice parameter for amyloid brain PET that was developed collaboratively by the ACR and the American Society for Neuroradiology (ASNR) [26], indications for amyloid PET mirror those of the amyloid imaging taskforce as above. FDG-PET/CT Brain PET imaging in dementia can be divided into metabolic PET, which uses FDG as a marker for metabolism, and amyloid PET, which uses agents that bind to amyloid deposits within the brain. FDG-PET imaging has been shown to provide greater diagnostic accuracy when compared with clinical evaluations without functional neuroimaging [27]. Hypometabolism on FDG-PET is thought to be related to decreased synaptic activity and is a biomarker of neurodegeneration or neuronal injury [12]. FDG-PET shows characteristic reductions of regional glucose metabolic rates in patients with probable and definite AD in the parietal, temporal, and posterior cingulate regions [28]. FDG- PET accurately discriminates AD patients from normal subjects with a sensitivity of 96% and specificity of 100% [28]. CMS has made FDG-PET available to Medicare recipients to assist with the diagnosis of dementia in the appropriate clinical setting (eg, to distinguish AD from FTD) in recognition of this usefulness [27]. A practice parameter for FDG-PET/CT for patients with cognitive decline has been developed collaboratively by the ACR-ASNR [26]. The qualifications and responsibilities of the personnel conducting the study and the standardized patient preparation, positioning, and protocol are also outlined in this document. An important detail to be emphasized is that the study should be performed at the request of physicians knowledgeable in clinical diagnosis and management of dementia and under circumstances in which the results of the examination are likely to impact patient care [26]. | 3111292 |
acrac_3111292_5 | Dementia | MR Spectroscopy Head MR spectroscopy may permit identification of mild to moderate AD with a specificity and sensitivity that suggests the potential for clinical usefulness and may predict the conversion of MCI to dementia [29]. Studies of automated MR spectroscopy for AD diagnosis have reported high sensitivity and moderate specificity. Findings in reported studies have varied, but decreased N-acetylaspartate (NAA) and increased myoinositol (mI) with the use of the NAA:mI ratio show the greatest promise [30]. However, prospective studies are lacking to validate this method for diagnosing AD. MRI Functional (fMRI) Head Recently tested as an imaging biomarker in AD is MRI functional (fMRI) because it may provide information about functional integrity of brain networks supportive memory and other cognitive domains [31]. Both conventional task-based fMRI and resting state fMRI (particularly the default mode network) [32] show promise as diagnostic markers but have not yet been subjected to a thorough validation. Most of the fMRI studies are single-center studies with small numbers of patients and limited test, retest, and cross-scanner reproducibility, limiting its use in the diagnosis of AD. MRI Head The primary role of neuroimaging in the workup of patients with probable or possible AD has typically been to exclude other significant intracranial abnormalities. A noncontrast MRI examination will assist with the diagnosis Dementia of dementia by excluding structural pathology like tumors or subdural hematomas [9]. Contrast-enhanced MRI is not needed in the initial imaging evaluation in dementia patients. Volumetric MRI can be used as a second-line imaging test for aiding in the diagnosis once the patient has been seen by a specialist. Medial temporal lobe atrophy has been noted to correlate with cognitive decline and nonfunctional test accumulation and is seen in patients with MCI compared with normal patients. | Dementia. MR Spectroscopy Head MR spectroscopy may permit identification of mild to moderate AD with a specificity and sensitivity that suggests the potential for clinical usefulness and may predict the conversion of MCI to dementia [29]. Studies of automated MR spectroscopy for AD diagnosis have reported high sensitivity and moderate specificity. Findings in reported studies have varied, but decreased N-acetylaspartate (NAA) and increased myoinositol (mI) with the use of the NAA:mI ratio show the greatest promise [30]. However, prospective studies are lacking to validate this method for diagnosing AD. MRI Functional (fMRI) Head Recently tested as an imaging biomarker in AD is MRI functional (fMRI) because it may provide information about functional integrity of brain networks supportive memory and other cognitive domains [31]. Both conventional task-based fMRI and resting state fMRI (particularly the default mode network) [32] show promise as diagnostic markers but have not yet been subjected to a thorough validation. Most of the fMRI studies are single-center studies with small numbers of patients and limited test, retest, and cross-scanner reproducibility, limiting its use in the diagnosis of AD. MRI Head The primary role of neuroimaging in the workup of patients with probable or possible AD has typically been to exclude other significant intracranial abnormalities. A noncontrast MRI examination will assist with the diagnosis Dementia of dementia by excluding structural pathology like tumors or subdural hematomas [9]. Contrast-enhanced MRI is not needed in the initial imaging evaluation in dementia patients. Volumetric MRI can be used as a second-line imaging test for aiding in the diagnosis once the patient has been seen by a specialist. Medial temporal lobe atrophy has been noted to correlate with cognitive decline and nonfunctional test accumulation and is seen in patients with MCI compared with normal patients. | 3111292 |
acrac_3111292_6 | Dementia | Atrophy measures can be a visual rating system (Scheltens score) [33], semiautomated, or automated volumetric techniques. Whole-brain and hippocampal atrophy rates are sensitive markers of progression of neurodegeneration and are increasingly used as surrogate outcomes in trials of potentially disease-modifying drugs. Volumetric MRI, along with FDG-PET and high CSF tau, is felt to be a biomarker of neurodegeneration or neuronal injury and could be able to document and follow disease severity [10,34]. In an evidence-based review of dementia diagnosis, the AAN did not recommend routine quantitative volumetry of the hippocampus or the entorhinal cortex because these techniques are labor intensive [9]. Diffusion-weighted imaging/apparent diffusion coefficient [35,36] and magnetization transfer imaging [37] are all either sensitive to early change or can add complementary information to atrophy measures but are second-line imaging tests. HMPAO SPECT or SPECT/CT Brain Regional cerebral blood flow determined using single-photon emission computed tomography (SPECT) imaging with Tc-99m hexamethylpropyleneamine oxime (HMPAO) shows bilateral temporoparietal or hippocampal hypoperfusion in patients with AD. Whether brain SPECT contributes substantially to diagnostic accuracy after a careful clinical examination using current diagnostic criteria is controversial. Although perfusion MRI is promising, SPECT remains superior in identifying pathologic perfusion [38]. An evidence-based review performed by the AAN concluded that SPECT imaging cannot be recommended for either the initial assessment or to clarify the differential diagnosis of suspected dementia because it has not demonstrated superiority to clinical criteria [9]. When compared with FDG-PET, SPECT has a lower diagnostic accuracy and is inferior in its ability to separate healthy controls from patients with true dementia [39,40]. Variant 2: Suspected frontotemporal dementia. Initial imaging. FTD is a neurodegenerative disorder that may be mistaken for AD. | Dementia. Atrophy measures can be a visual rating system (Scheltens score) [33], semiautomated, or automated volumetric techniques. Whole-brain and hippocampal atrophy rates are sensitive markers of progression of neurodegeneration and are increasingly used as surrogate outcomes in trials of potentially disease-modifying drugs. Volumetric MRI, along with FDG-PET and high CSF tau, is felt to be a biomarker of neurodegeneration or neuronal injury and could be able to document and follow disease severity [10,34]. In an evidence-based review of dementia diagnosis, the AAN did not recommend routine quantitative volumetry of the hippocampus or the entorhinal cortex because these techniques are labor intensive [9]. Diffusion-weighted imaging/apparent diffusion coefficient [35,36] and magnetization transfer imaging [37] are all either sensitive to early change or can add complementary information to atrophy measures but are second-line imaging tests. HMPAO SPECT or SPECT/CT Brain Regional cerebral blood flow determined using single-photon emission computed tomography (SPECT) imaging with Tc-99m hexamethylpropyleneamine oxime (HMPAO) shows bilateral temporoparietal or hippocampal hypoperfusion in patients with AD. Whether brain SPECT contributes substantially to diagnostic accuracy after a careful clinical examination using current diagnostic criteria is controversial. Although perfusion MRI is promising, SPECT remains superior in identifying pathologic perfusion [38]. An evidence-based review performed by the AAN concluded that SPECT imaging cannot be recommended for either the initial assessment or to clarify the differential diagnosis of suspected dementia because it has not demonstrated superiority to clinical criteria [9]. When compared with FDG-PET, SPECT has a lower diagnostic accuracy and is inferior in its ability to separate healthy controls from patients with true dementia [39,40]. Variant 2: Suspected frontotemporal dementia. Initial imaging. FTD is a neurodegenerative disorder that may be mistaken for AD. | 3111292 |
acrac_3111292_7 | Dementia | Pathologically, it includes a heterogeneous group of sporadic and familial neuropsychiatric disorders. Pick disease is one of the neuropathological entities of FTD. Unlike AD, which increases in frequency with age, FTD is rare after the age of 75. Although the diagnosis of FTD is primarily clinical, neuroimaging serves several purposes: exclusion of other structural brain abnormalities that could clinically mimic FTD, differentiation of FTD from other neurodegenerative disorders (most commonly AD), and classification of the known subtypes of FTD [43]. Multimodal imaging is a promising approach in neuroimaging of FTD. Integrated PET/MRI systems allow a combination of structural and functional imaging in one examination that can increase sensitivity and specificity of these modalities in a smaller cohort of patients and thus may represent a method of choice in FTD [44]. CT Head Noncontrast CT head is used to exclude other lesions that may clinically mimic the disease. CT head with intravenous (IV) contrast or dual-phase imaging is not needed for initial evaluation. Dementia Amyloid PET/CT Brain Use of amyloid PET in FTD is limited to the exclusion of underlying amyloid brain pathology that can be seen in cases of AD with atypical presentation. PET tracers specific for tau protein deposits in the brain are currently being investigated, but no systematic studies on their application in FTD have been published [44]. FDG-PET/CT Brain FDG-PET is an established tool for differentiating FTD and AD and classifying different FTD subtypes. FDG-PET has a sensitivity of 60% and a positive predictive value of 78.5% for differentiating the subtypes of FTD [44]. The CMS coverage decision for payment for FDG-PET brain, in 2004, was based on FDG brain PET being a very valuable diagnostic study to differentiate AD and FTD in patients with documented cognitive decline of at least 6 months and a recently established diagnosis of dementia [45]. | Dementia. Pathologically, it includes a heterogeneous group of sporadic and familial neuropsychiatric disorders. Pick disease is one of the neuropathological entities of FTD. Unlike AD, which increases in frequency with age, FTD is rare after the age of 75. Although the diagnosis of FTD is primarily clinical, neuroimaging serves several purposes: exclusion of other structural brain abnormalities that could clinically mimic FTD, differentiation of FTD from other neurodegenerative disorders (most commonly AD), and classification of the known subtypes of FTD [43]. Multimodal imaging is a promising approach in neuroimaging of FTD. Integrated PET/MRI systems allow a combination of structural and functional imaging in one examination that can increase sensitivity and specificity of these modalities in a smaller cohort of patients and thus may represent a method of choice in FTD [44]. CT Head Noncontrast CT head is used to exclude other lesions that may clinically mimic the disease. CT head with intravenous (IV) contrast or dual-phase imaging is not needed for initial evaluation. Dementia Amyloid PET/CT Brain Use of amyloid PET in FTD is limited to the exclusion of underlying amyloid brain pathology that can be seen in cases of AD with atypical presentation. PET tracers specific for tau protein deposits in the brain are currently being investigated, but no systematic studies on their application in FTD have been published [44]. FDG-PET/CT Brain FDG-PET is an established tool for differentiating FTD and AD and classifying different FTD subtypes. FDG-PET has a sensitivity of 60% and a positive predictive value of 78.5% for differentiating the subtypes of FTD [44]. The CMS coverage decision for payment for FDG-PET brain, in 2004, was based on FDG brain PET being a very valuable diagnostic study to differentiate AD and FTD in patients with documented cognitive decline of at least 6 months and a recently established diagnosis of dementia [45]. | 3111292 |
acrac_3111292_8 | Dementia | MR Spectroscopy Head MR spectroscopy metabolite changes in FTD are similar to the changes encountered in AD: lower NAA to creatine (Cr) ratio (NAA/Cr) and higher mI to Cr ratio (mI/Cr) than normal, but findings are more commonly centered on the frontal cortex in early FTD [46]. MR spectroscopy could be a helpful secondary test in patients who have clinical findings of FTD, but it is not a first-line imaging test. MRI Functional (fMRI) Head Brain activation has been shown to be significantly decreased in FTD in the frontal and parietal lobes compared with AD [47]. Resting state fMRI demonstrates alterations in structural and functional connectivity in presymptomatic FTD [48]. However, fMRI remains in the realm of research and is not recommended in routine evaluation of FTD. MRI Head MRI of the brain without IV contrast serves as a first-line imaging test to exclude secondary causes of symptoms such as subdural hematoma and tumor in patients with suspected FTD. IV contrast is not necessary for initial evaluation. Volumetric MRI has a second-level role in diagnosis and has been actively studied as a tool to assess brain atrophy patterns associated with different FTD clinical phenotypes. Studies show that volumetric MRI allows differentiation of atrophy patterns when analyzed at a group level but currently does not allow assessment on an individual patient level [44]. Several other advanced MRI techniques provide additional information about brain microstructure, and their role in diagnosis of FTD is being investigated [44]. Zhang et al [49] demonstrated that diffusion tensor imaging has significantly greater accuracy for classifying subtypes of FTD than volumetric brain MRI. The role of arterial spin labeling MRI in FTD is currently being studied. The patterns detected using arterial spin labeling MRI has been shown to be similar to FDG-PET findings, and this technique potentially could represent a future alternative to FDG-PET [44]. | Dementia. MR Spectroscopy Head MR spectroscopy metabolite changes in FTD are similar to the changes encountered in AD: lower NAA to creatine (Cr) ratio (NAA/Cr) and higher mI to Cr ratio (mI/Cr) than normal, but findings are more commonly centered on the frontal cortex in early FTD [46]. MR spectroscopy could be a helpful secondary test in patients who have clinical findings of FTD, but it is not a first-line imaging test. MRI Functional (fMRI) Head Brain activation has been shown to be significantly decreased in FTD in the frontal and parietal lobes compared with AD [47]. Resting state fMRI demonstrates alterations in structural and functional connectivity in presymptomatic FTD [48]. However, fMRI remains in the realm of research and is not recommended in routine evaluation of FTD. MRI Head MRI of the brain without IV contrast serves as a first-line imaging test to exclude secondary causes of symptoms such as subdural hematoma and tumor in patients with suspected FTD. IV contrast is not necessary for initial evaluation. Volumetric MRI has a second-level role in diagnosis and has been actively studied as a tool to assess brain atrophy patterns associated with different FTD clinical phenotypes. Studies show that volumetric MRI allows differentiation of atrophy patterns when analyzed at a group level but currently does not allow assessment on an individual patient level [44]. Several other advanced MRI techniques provide additional information about brain microstructure, and their role in diagnosis of FTD is being investigated [44]. Zhang et al [49] demonstrated that diffusion tensor imaging has significantly greater accuracy for classifying subtypes of FTD than volumetric brain MRI. The role of arterial spin labeling MRI in FTD is currently being studied. The patterns detected using arterial spin labeling MRI has been shown to be similar to FDG-PET findings, and this technique potentially could represent a future alternative to FDG-PET [44]. | 3111292 |
acrac_3111292_9 | Dementia | HMPAO SPECT or SPECT/CT Brain Tc-99m HMPAO SPECT has been found to be useful in distinguishing FTD from AD and VaD with a pattern of bilateral anterior hypoperfusion. Tc-99m HMPAO SPECT may be used as an adjunct to clinical evaluation and CT but it is not a first-line test [50]. Variant 3: Suspected dementia with Lewy bodies. Initial imaging. Dementia with Lewy bodies (DLB) has been recognized as the second most prevalent neurodegenerative dementia in the elderly, causing up to 15% of cases [51]. It is a synucleinopathy with accumulation of insoluble alpha- Synuclein that aggregates to form Lewy bodies, which are the major pathological feature of the disease. To increase the accuracy of diagnosis of DLB, the latest diagnostic criteria incorporate findings from neuroimaging such as CT, MRI, SPECT, and PET [52]. Some authors have suggested a multimodality approach combining MRI and SPECT modalities as a useful and practical approach for differentiating DLB from AD [51]. CT Head Noncontrast CT head is a good first-line examination to exclude mimics like brain tumor or subdural hematoma. Relative preservation of the medial temporal lobe structures is also a supportive imaging biomarker according to the fourth consensus report of the DLB consortium [52]. CT with IV contrast or dual-phase CT imaging is not needed for initial evaluation. Dementia Amyloid PET/CT Brain DLB is also accompanied by amyloid deposition like AD, but overall, there is decreased uptake compared when with AD patients on amyloid imaging. Compared to Parkinson disease, DLB patients show a higher level of amyloid deposition [53]. At this time, amyloid PET/CT has very limited usefulness for diagnosis of DLB. Ioflupane SPECT or SPECT/CT Brain In the present guidelines, decreased dopamine transporter uptake is of the greatest importance among various neuroimaging findings and is listed as one of the suggestive features. | Dementia. HMPAO SPECT or SPECT/CT Brain Tc-99m HMPAO SPECT has been found to be useful in distinguishing FTD from AD and VaD with a pattern of bilateral anterior hypoperfusion. Tc-99m HMPAO SPECT may be used as an adjunct to clinical evaluation and CT but it is not a first-line test [50]. Variant 3: Suspected dementia with Lewy bodies. Initial imaging. Dementia with Lewy bodies (DLB) has been recognized as the second most prevalent neurodegenerative dementia in the elderly, causing up to 15% of cases [51]. It is a synucleinopathy with accumulation of insoluble alpha- Synuclein that aggregates to form Lewy bodies, which are the major pathological feature of the disease. To increase the accuracy of diagnosis of DLB, the latest diagnostic criteria incorporate findings from neuroimaging such as CT, MRI, SPECT, and PET [52]. Some authors have suggested a multimodality approach combining MRI and SPECT modalities as a useful and practical approach for differentiating DLB from AD [51]. CT Head Noncontrast CT head is a good first-line examination to exclude mimics like brain tumor or subdural hematoma. Relative preservation of the medial temporal lobe structures is also a supportive imaging biomarker according to the fourth consensus report of the DLB consortium [52]. CT with IV contrast or dual-phase CT imaging is not needed for initial evaluation. Dementia Amyloid PET/CT Brain DLB is also accompanied by amyloid deposition like AD, but overall, there is decreased uptake compared when with AD patients on amyloid imaging. Compared to Parkinson disease, DLB patients show a higher level of amyloid deposition [53]. At this time, amyloid PET/CT has very limited usefulness for diagnosis of DLB. Ioflupane SPECT or SPECT/CT Brain In the present guidelines, decreased dopamine transporter uptake is of the greatest importance among various neuroimaging findings and is listed as one of the suggestive features. | 3111292 |
acrac_3111292_10 | Dementia | Functional imaging of the dopamine transporter (I-123 Ioflupane) using SPECT might identify a defect in the nigrostriatal pathway that occurs in a variety of disorders including DLB and Parkinson disease. I-123 Ioflupane striatal activity tends to be normal in AD and low in DLB and Parkinson disease; however, AD and DLB can coexist in the same patient, potentially confounding results [11,51]. This is not a first-line imaging test but may be valuable after cross-sectional imaging to exclude other pathology. MR Spectroscopy Head There is sparse MR spectroscopy data on DLB. In one study [55], DLB patients were characterized by decreased NAA/Cr in the occipital voxel. AD patients were characterized by lower NAA/Cr in the frontal and posterior cingulate voxels. Normal NAA/Cr levels in the frontal voxel differentiated DLB patients with preserved hippocampal volumes from AD patients. MR spectroscopy abnormalities associated with loss of neuronal integrity localized to the occipital lobes in DLB, and the posterior cingulate gyri and frontal lobes in AD. The pattern of MR spectroscopy abnormalities may have a role in differential diagnosis of DLB and in distinguishing DLB patients with overlapping AD pathology. Although in the future, MR spectroscopy can provide additional useful information in the ante-mortem diagnosis of DLB; at present, its usefulness is limited. MRI functional (fMRI) Head Studies with fMRI show reduced activation of the occipital-temporal lobe regions during visual tasks. Resting state fMRI has demonstrated increased functional connectivity between the right posterior cingulate gyrus and other regions of the brain and reduced cortico-cortical connectivity. However, the diagnostic utility of fMRI for diagnosis of DLB has not been validated, and thus it cannot be recommended [56]. MRI Head Routine MRI head is performed to exclude other lesions like tumor or subdural hematoma. Contrast-enhanced MRI is not needed for initial evaluation. | Dementia. Functional imaging of the dopamine transporter (I-123 Ioflupane) using SPECT might identify a defect in the nigrostriatal pathway that occurs in a variety of disorders including DLB and Parkinson disease. I-123 Ioflupane striatal activity tends to be normal in AD and low in DLB and Parkinson disease; however, AD and DLB can coexist in the same patient, potentially confounding results [11,51]. This is not a first-line imaging test but may be valuable after cross-sectional imaging to exclude other pathology. MR Spectroscopy Head There is sparse MR spectroscopy data on DLB. In one study [55], DLB patients were characterized by decreased NAA/Cr in the occipital voxel. AD patients were characterized by lower NAA/Cr in the frontal and posterior cingulate voxels. Normal NAA/Cr levels in the frontal voxel differentiated DLB patients with preserved hippocampal volumes from AD patients. MR spectroscopy abnormalities associated with loss of neuronal integrity localized to the occipital lobes in DLB, and the posterior cingulate gyri and frontal lobes in AD. The pattern of MR spectroscopy abnormalities may have a role in differential diagnosis of DLB and in distinguishing DLB patients with overlapping AD pathology. Although in the future, MR spectroscopy can provide additional useful information in the ante-mortem diagnosis of DLB; at present, its usefulness is limited. MRI functional (fMRI) Head Studies with fMRI show reduced activation of the occipital-temporal lobe regions during visual tasks. Resting state fMRI has demonstrated increased functional connectivity between the right posterior cingulate gyrus and other regions of the brain and reduced cortico-cortical connectivity. However, the diagnostic utility of fMRI for diagnosis of DLB has not been validated, and thus it cannot be recommended [56]. MRI Head Routine MRI head is performed to exclude other lesions like tumor or subdural hematoma. Contrast-enhanced MRI is not needed for initial evaluation. | 3111292 |
acrac_3111292_11 | Dementia | Volumetric MRI can be done as a secondary test to support the diagnosis. On structural MRI, patients with DLB show less atrophy of the hippocampus and other medial temporal lobe structures compared with AD. For similar levels of dementia severity, DLB appears to have greater subcortical structure atrophy (thalamus, caudate, amygdala, ventral diencephalon, substantia nigra, and midbrain) compared with AD [57]. However, on a single subject level, structural changes are not helpful in differentiating DLB from other dementias. Diffusion tensor imaging studies have described the potential importance of the precuneus in the pathogenesis of DLB as well as AD [35]. HMPAO SPECT or SPECT/CT Brain The most important finding on brain-perfusion SPECT in DLB is occipital hypoperfusion. This hypoperfusion is listed as a supportive feature in the consensus guidelines [52], and this can be a second-line imaging test to help with the diagnosis. However, this test is less commonly used in clinical practice and has been largely replaced by other imaging modalities. Variant 4: Suspected vascular dementia. Initial imaging. Cerebral vascular disease, especially common in the elderly, can lead to VaD [11]. The diagnosis of VaD involves the presence of significant cerebrovascular pathology or risk factors, assessed clinically or using neuroimaging. Recently, the concept of vascular cognitive impairment has been invoked, which refers to the whole spectrum of Dementia disorders in which there is cognitive impairment and either clinical evidence of previous stroke or imaging evidence of vascular brain injury, either in isolation (pure vascular disease) or in association with other pathologies (mixed disease) [58]. The three main causes of vascular cognitive impairment are large vessel strokes (macroangiopathy, arteriosclerosis), small vessel disease (microangiopathy, arteriolosclerosis), and microhemorrhages. Structural neuroimaging has been incorporated as an important element of the diagnosis of VaD [59]. | Dementia. Volumetric MRI can be done as a secondary test to support the diagnosis. On structural MRI, patients with DLB show less atrophy of the hippocampus and other medial temporal lobe structures compared with AD. For similar levels of dementia severity, DLB appears to have greater subcortical structure atrophy (thalamus, caudate, amygdala, ventral diencephalon, substantia nigra, and midbrain) compared with AD [57]. However, on a single subject level, structural changes are not helpful in differentiating DLB from other dementias. Diffusion tensor imaging studies have described the potential importance of the precuneus in the pathogenesis of DLB as well as AD [35]. HMPAO SPECT or SPECT/CT Brain The most important finding on brain-perfusion SPECT in DLB is occipital hypoperfusion. This hypoperfusion is listed as a supportive feature in the consensus guidelines [52], and this can be a second-line imaging test to help with the diagnosis. However, this test is less commonly used in clinical practice and has been largely replaced by other imaging modalities. Variant 4: Suspected vascular dementia. Initial imaging. Cerebral vascular disease, especially common in the elderly, can lead to VaD [11]. The diagnosis of VaD involves the presence of significant cerebrovascular pathology or risk factors, assessed clinically or using neuroimaging. Recently, the concept of vascular cognitive impairment has been invoked, which refers to the whole spectrum of Dementia disorders in which there is cognitive impairment and either clinical evidence of previous stroke or imaging evidence of vascular brain injury, either in isolation (pure vascular disease) or in association with other pathologies (mixed disease) [58]. The three main causes of vascular cognitive impairment are large vessel strokes (macroangiopathy, arteriosclerosis), small vessel disease (microangiopathy, arteriolosclerosis), and microhemorrhages. Structural neuroimaging has been incorporated as an important element of the diagnosis of VaD [59]. | 3111292 |
acrac_3111292_12 | Dementia | Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy is an autosomal- dominant hereditary small-artery vasculopathy caused by mutations in the notch3 gene on chromosome 19. Clinically, the disease is characterized by migraine with aura, strokes and progressive subcortical dementia, and mood disturbances. MRI in these patients shows focal lacunar infarcts and leukoaraiosis. Lesion load increases with age. Besides familial anamnesis and clinical history, structural MRI changes in these patients help to suggest the diagnosis by showing characteristic hyperintense T2 or fluid-attenuated inversion recovery lesions, which predominate in the frontal, parietal, and anterior temporal cortexes and in the external capsule [60]. Diagnosis is confirmed by skin biopsy or detection of a pathogenic notch3 mutation on direct sequencing. CT Head Most acute stroke patients undergo brain imaging by unenhanced CT head to evaluate for size, territory, and acuity of infarct to exclude hemorrhage and evaluate for stroke mimics (such as brain tumors). Furthermore, the presence and severity of white matter changes and brain atrophy can also be readily determined from CT head imaging. CT head with IV contrast is not needed to evaluate VaD. CTA Head CT angiography (CTA) is a sensitive modality and may be used as an alternative to MR angiography (MRA) to detect vascular occlusion or stenosis intracranially. However, vascular imaging is not needed to make a diagnosis of VaD; rather, the diagnosis relies on clinical criteria and evidence of end organ damage in the brain. FDG-PET/CT Brain FDG-PET/CT in VaD can show multiple focal cortical and subcortical metabolic defects, a pattern different from AD and may be useful in differentiating the two entities in the demented patient [61]; however, it is not a first-line imaging test. MR Spectroscopy Head MR spectroscopy shows injury to the axons by measuring the levels of NAA and Cr [62,63]. | Dementia. Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy is an autosomal- dominant hereditary small-artery vasculopathy caused by mutations in the notch3 gene on chromosome 19. Clinically, the disease is characterized by migraine with aura, strokes and progressive subcortical dementia, and mood disturbances. MRI in these patients shows focal lacunar infarcts and leukoaraiosis. Lesion load increases with age. Besides familial anamnesis and clinical history, structural MRI changes in these patients help to suggest the diagnosis by showing characteristic hyperintense T2 or fluid-attenuated inversion recovery lesions, which predominate in the frontal, parietal, and anterior temporal cortexes and in the external capsule [60]. Diagnosis is confirmed by skin biopsy or detection of a pathogenic notch3 mutation on direct sequencing. CT Head Most acute stroke patients undergo brain imaging by unenhanced CT head to evaluate for size, territory, and acuity of infarct to exclude hemorrhage and evaluate for stroke mimics (such as brain tumors). Furthermore, the presence and severity of white matter changes and brain atrophy can also be readily determined from CT head imaging. CT head with IV contrast is not needed to evaluate VaD. CTA Head CT angiography (CTA) is a sensitive modality and may be used as an alternative to MR angiography (MRA) to detect vascular occlusion or stenosis intracranially. However, vascular imaging is not needed to make a diagnosis of VaD; rather, the diagnosis relies on clinical criteria and evidence of end organ damage in the brain. FDG-PET/CT Brain FDG-PET/CT in VaD can show multiple focal cortical and subcortical metabolic defects, a pattern different from AD and may be useful in differentiating the two entities in the demented patient [61]; however, it is not a first-line imaging test. MR Spectroscopy Head MR spectroscopy shows injury to the axons by measuring the levels of NAA and Cr [62,63]. | 3111292 |
acrac_3111292_13 | Dementia | MR spectroscopy is a research tool and, to date, does not appear to clinically help establish a diagnosis of VaD or mixed VaD and AD. MRA Head Although vascular imaging is not needed for diagnosis of suspected VaD, MRA is a sensitive modality to detect vascular occlusion or stenosis intracranially. MRA Neck Vascular imaging is not needed for workup of suspected VaD. MRI functional (fMRI) Head The use of fMRI is investigational and, to date, does not appear to clinically help establish a diagnosis of VaD or mixed VaD and AD. MRI Head One of the roles of neuroimaging is to document the presence or absence of strokes. Although CT can detect the presence or absence of infarctions in patients with dementia, histopathologically verified cases of VaD with normal CT studies have been reported [28]. Thus, MRI is preferable to CT for detecting vascular lesions in patients with dementia. On MRI, evidence for vascular abnormalities includes cortical or subcortical infarcts, leukoariosis or white matter T2 hyperintensity, microhemorrhages, and lacunar infarct. Hippocampal atrophy has been seen in patients with vascular cognitive impairment [64], and some studies have argued that it is the best predictor of post stroke dementia [65]. The above-mentioned imaging findings on routine MRI lack specificity and correlation with degree of cognitive impairment. Diffusion tensor imaging has been shown to correlate better with cognitive deficits, but its use has been confined to research settings [66]. Differentiation of VaD from either AD with superimposed cerebrovascular disease or mixed AD and VaD is especially difficult and is best performed by amyloid PET/CT brain. On MRI, extensive infarctions (cortical or Dementia lacunar or both) and white-matter changes (hyperintense on T2-weighted MRI) in a patient with dementia favor a contribution from VaD or mixed VaD and AD over AD. The absence or mild extent of these changes in a patient with dementia argues against a diagnosis of VaD. | Dementia. MR spectroscopy is a research tool and, to date, does not appear to clinically help establish a diagnosis of VaD or mixed VaD and AD. MRA Head Although vascular imaging is not needed for diagnosis of suspected VaD, MRA is a sensitive modality to detect vascular occlusion or stenosis intracranially. MRA Neck Vascular imaging is not needed for workup of suspected VaD. MRI functional (fMRI) Head The use of fMRI is investigational and, to date, does not appear to clinically help establish a diagnosis of VaD or mixed VaD and AD. MRI Head One of the roles of neuroimaging is to document the presence or absence of strokes. Although CT can detect the presence or absence of infarctions in patients with dementia, histopathologically verified cases of VaD with normal CT studies have been reported [28]. Thus, MRI is preferable to CT for detecting vascular lesions in patients with dementia. On MRI, evidence for vascular abnormalities includes cortical or subcortical infarcts, leukoariosis or white matter T2 hyperintensity, microhemorrhages, and lacunar infarct. Hippocampal atrophy has been seen in patients with vascular cognitive impairment [64], and some studies have argued that it is the best predictor of post stroke dementia [65]. The above-mentioned imaging findings on routine MRI lack specificity and correlation with degree of cognitive impairment. Diffusion tensor imaging has been shown to correlate better with cognitive deficits, but its use has been confined to research settings [66]. Differentiation of VaD from either AD with superimposed cerebrovascular disease or mixed AD and VaD is especially difficult and is best performed by amyloid PET/CT brain. On MRI, extensive infarctions (cortical or Dementia lacunar or both) and white-matter changes (hyperintense on T2-weighted MRI) in a patient with dementia favor a contribution from VaD or mixed VaD and AD over AD. The absence or mild extent of these changes in a patient with dementia argues against a diagnosis of VaD. | 3111292 |
acrac_3111292_14 | Dementia | The abovementioned findings are optimally visualized on noncontrast MRI; IV contrast is not needed. US Duplex Doppler Carotid Artery Atherosclerotic burden, as defined by carotid ultrasound (US), is associated with worse cognitive performance and subsequent cognitive decline [67]. However, US duplex Doppler is not needed to diagnose VaD. Variant 5: Suspected idiopathic normal-pressure hydrocephalus. Initial imaging. Normal-pressure hydrocephalus (NPH) is characterized by the clinical triad of dementia, gait disturbance, and urinary incontinence. Other diagnostic features include normal CSF pressure at lumbar puncture, communicating hydrocephalus documented on MRI or CT, and ventricular influx but no passage of isotope over the convexities on radionuclide DTPA cisternography. The Guideline Development, Dissemination, and Implementation Subcommittee of the AAN has concluded that shunting is possibly effective in idiopathic NPH (INPH) [68]. Several clinical, laboratory, and imaging signs can improve distinction between responders and nonresponders to shunting. However, there is no test or combination of clinical findings and tests that accurately predicts response to shunting. Clinical features that favor shunt responsiveness include predominance of gait disturbance, mild to moderate degree of dementia, and rapid clinical progression of urinary incontinence. Imaging features of responders versus nonresponders are discussed below. CT Head CT head without IV contrast is an appropriate first-line imaging test to evaluate for ventriculomegaly out of proportion to sulci and to exclude other pathologies. It can also show transependymal CSF flow. CT head with IV contrast is not indicated for initial evaluation of NPH. MR Spectroscopy Head MR spectroscopy is not useful in differentiating INPH from other types of dementia nor does it help in patient selection for ventriculoperitoneal shunting [69]. | Dementia. The abovementioned findings are optimally visualized on noncontrast MRI; IV contrast is not needed. US Duplex Doppler Carotid Artery Atherosclerotic burden, as defined by carotid ultrasound (US), is associated with worse cognitive performance and subsequent cognitive decline [67]. However, US duplex Doppler is not needed to diagnose VaD. Variant 5: Suspected idiopathic normal-pressure hydrocephalus. Initial imaging. Normal-pressure hydrocephalus (NPH) is characterized by the clinical triad of dementia, gait disturbance, and urinary incontinence. Other diagnostic features include normal CSF pressure at lumbar puncture, communicating hydrocephalus documented on MRI or CT, and ventricular influx but no passage of isotope over the convexities on radionuclide DTPA cisternography. The Guideline Development, Dissemination, and Implementation Subcommittee of the AAN has concluded that shunting is possibly effective in idiopathic NPH (INPH) [68]. Several clinical, laboratory, and imaging signs can improve distinction between responders and nonresponders to shunting. However, there is no test or combination of clinical findings and tests that accurately predicts response to shunting. Clinical features that favor shunt responsiveness include predominance of gait disturbance, mild to moderate degree of dementia, and rapid clinical progression of urinary incontinence. Imaging features of responders versus nonresponders are discussed below. CT Head CT head without IV contrast is an appropriate first-line imaging test to evaluate for ventriculomegaly out of proportion to sulci and to exclude other pathologies. It can also show transependymal CSF flow. CT head with IV contrast is not indicated for initial evaluation of NPH. MR Spectroscopy Head MR spectroscopy is not useful in differentiating INPH from other types of dementia nor does it help in patient selection for ventriculoperitoneal shunting [69]. | 3111292 |
acrac_3195158_0 | Thoracic Back Pain | Introduction/Background In the United States, spinal pain is one of the leading causes of disability, health care costs, and emergency room visits [1,2]. The lumbar and cervical spine regions have been extensively studied and have well-established associations with pain and disability. Comparatively, thoracic back pain (TBP) has received less attention in terms of genetic and epidemiological research [3]. However, the thoracic spine is a common site for inflammatory, neoplastic, metabolic, infectious, and degenerative conditions [3]. Therefore, TBP may be equally disabling and associated with significant morbidity. Uncomplicated acute TBP and/or radiculopathy may be a benign, self-limited condition that does not warrant any imaging studies [5-8]. Imaging may be considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain. Imaging may also be considered for those patients presenting with red flags, raising suspicion for a serious underlying condition, such as symptomatic spinal canal stenosis, cord deformity or compression, malignancy, fracture, or infection [9,10]. For those patients with significant trauma, myelopathy, or prior thoracic spine fusion, early imaging may also be warranted [11-14]. Because the thoracic spine is a common site for osteoporotic compression fractures [15-17], early imaging should also be considered in patients with known osteoporosis or risk factors such as >65 years of age or chronic steroid use [18]. For those patients without neurologic compromise and who present with minor risk factors for cancer, inflammatory back disease (eg, ankylosing spondylitis), vertebral compression fracture, or symptomatic spinal stenosis, imaging may be considered after a trial of therapy. Initial Imaging Definition Initial imaging is defined as imaging at the beginning of the care episode for the medical condition defined by the variant. | Thoracic Back Pain. Introduction/Background In the United States, spinal pain is one of the leading causes of disability, health care costs, and emergency room visits [1,2]. The lumbar and cervical spine regions have been extensively studied and have well-established associations with pain and disability. Comparatively, thoracic back pain (TBP) has received less attention in terms of genetic and epidemiological research [3]. However, the thoracic spine is a common site for inflammatory, neoplastic, metabolic, infectious, and degenerative conditions [3]. Therefore, TBP may be equally disabling and associated with significant morbidity. Uncomplicated acute TBP and/or radiculopathy may be a benign, self-limited condition that does not warrant any imaging studies [5-8]. Imaging may be considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain. Imaging may also be considered for those patients presenting with red flags, raising suspicion for a serious underlying condition, such as symptomatic spinal canal stenosis, cord deformity or compression, malignancy, fracture, or infection [9,10]. For those patients with significant trauma, myelopathy, or prior thoracic spine fusion, early imaging may also be warranted [11-14]. Because the thoracic spine is a common site for osteoporotic compression fractures [15-17], early imaging should also be considered in patients with known osteoporosis or risk factors such as >65 years of age or chronic steroid use [18]. For those patients without neurologic compromise and who present with minor risk factors for cancer, inflammatory back disease (eg, ankylosing spondylitis), vertebral compression fracture, or symptomatic spinal stenosis, imaging may be considered after a trial of therapy. Initial Imaging Definition Initial imaging is defined as imaging at the beginning of the care episode for the medical condition defined by the variant. | 3195158 |
acrac_3195158_1 | Thoracic Back Pain | More than one procedure can be considered usually appropriate in the initial imaging evaluation when: The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: [email protected] OR Discussion of Procedures by Variant Variant 1: Adult. Acute Thoracic back pain without myelopathy or radiculopathy. No red flags. No prior management. Initial imaging. There is a lack of evidence supporting or refuting imaging early or before conservative treatment for TBP [3,20]. However, extrapolating from the low back pain (LBP) evidence, imaging is typically not warranted in this setting. Acute (<4 weeks duration), uncomplicated (no red flags) LBP with or without radiculopathy, is considered a self- limiting condition that is responsive to medical management and physical therapy in most patients [5-8]. Numerous studies have shown routine imaging provides no clinical benefit in this LBP group [6]. Thoracic disc disease is less common than in the cervical or lumbar spine [21]. This may be due to the fact that the thoracic spine is the only portion of the spine with additional structures (ie, ribs) to help in weight-bearing. There is also relatively limited mobility in the thoracic spine as the costovertebral joint limits flexion, the rib cage limits rotation and lateral bending, and the discs are relatively small in size compared to the cervical or lumbar spine. Symptomatic thoracic disc disease occurs most frequently below the level of T7. Thoracic disc abnormalities such as herniations, bulges, annular fissures, and cord contour deformity are common in asymptomatic patients [22]. | Thoracic Back Pain. More than one procedure can be considered usually appropriate in the initial imaging evaluation when: The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: [email protected] OR Discussion of Procedures by Variant Variant 1: Adult. Acute Thoracic back pain without myelopathy or radiculopathy. No red flags. No prior management. Initial imaging. There is a lack of evidence supporting or refuting imaging early or before conservative treatment for TBP [3,20]. However, extrapolating from the low back pain (LBP) evidence, imaging is typically not warranted in this setting. Acute (<4 weeks duration), uncomplicated (no red flags) LBP with or without radiculopathy, is considered a self- limiting condition that is responsive to medical management and physical therapy in most patients [5-8]. Numerous studies have shown routine imaging provides no clinical benefit in this LBP group [6]. Thoracic disc disease is less common than in the cervical or lumbar spine [21]. This may be due to the fact that the thoracic spine is the only portion of the spine with additional structures (ie, ribs) to help in weight-bearing. There is also relatively limited mobility in the thoracic spine as the costovertebral joint limits flexion, the rib cage limits rotation and lateral bending, and the discs are relatively small in size compared to the cervical or lumbar spine. Symptomatic thoracic disc disease occurs most frequently below the level of T7. Thoracic disc abnormalities such as herniations, bulges, annular fissures, and cord contour deformity are common in asymptomatic patients [22]. | 3195158 |
acrac_3195158_2 | Thoracic Back Pain | Thoracic disc imaging abnormalities can therefore be seen in a substantial number of people without mid back pain. With regards to thoracic facet joints, as in the lumbar spine, morphologic imaging changes of osteoarthritis do not correlate with pain [23]. Bone Scan Whole Body There is no relevant literature to support the use of bone scans whole body in the initial evaluation of acute uncomplicated TBP. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scans with single-photon emission CT (SPECT) or SPECT/CT thoracic spine in the initial evaluation of acute uncomplicated TBP. CT Myelography Thoracic Spine There is no relevant literature to support the use of CT myelography thoracic spine in the initial evaluation of acute uncomplicated TBP. No radiologic distinction has been noted between asymptomatic and symptomatic discs on postmyelographic CT [24]. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with intravenous (IV) contrast in the initial evaluation of acute uncomplicated TBP. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial evaluation of acute uncomplicated TBP. CT Thoracic Spine Without IV Contrast There is no relevant literature to support the use of CT thoracic spine without IV contrast in the initial evaluation of acute uncomplicated TBP. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT skull base to mid-thigh in the initial evaluation of acute uncomplicated TBP. MRI Thoracic Spine With IV Contrast There is no relevant literature to support the use of MRI thoracic spine with IV contrast in the initial evaluation of acute uncomplicated TBP. Thoracic Back Pain | Thoracic Back Pain. Thoracic disc imaging abnormalities can therefore be seen in a substantial number of people without mid back pain. With regards to thoracic facet joints, as in the lumbar spine, morphologic imaging changes of osteoarthritis do not correlate with pain [23]. Bone Scan Whole Body There is no relevant literature to support the use of bone scans whole body in the initial evaluation of acute uncomplicated TBP. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scans with single-photon emission CT (SPECT) or SPECT/CT thoracic spine in the initial evaluation of acute uncomplicated TBP. CT Myelography Thoracic Spine There is no relevant literature to support the use of CT myelography thoracic spine in the initial evaluation of acute uncomplicated TBP. No radiologic distinction has been noted between asymptomatic and symptomatic discs on postmyelographic CT [24]. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with intravenous (IV) contrast in the initial evaluation of acute uncomplicated TBP. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial evaluation of acute uncomplicated TBP. CT Thoracic Spine Without IV Contrast There is no relevant literature to support the use of CT thoracic spine without IV contrast in the initial evaluation of acute uncomplicated TBP. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT skull base to mid-thigh in the initial evaluation of acute uncomplicated TBP. MRI Thoracic Spine With IV Contrast There is no relevant literature to support the use of MRI thoracic spine with IV contrast in the initial evaluation of acute uncomplicated TBP. Thoracic Back Pain | 3195158 |
acrac_3195158_3 | Thoracic Back Pain | MRI Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of MRI thoracic spine without and with IV contrast in the initial evaluation of acute uncomplicated TBP. MRI Thoracic Spine Without IV Contrast There is no relevant literature to support the use of MRI thoracic spine without IV contrast in the initial evaluation of acute uncomplicated TBP. Radiography Thoracic Spine There is no relevant literature to support the use of radiography in the initial evaluation of acute uncomplicated TBP. Variant 2: Adult. Subacute or chronic thoracic back pain without myelopathy or radiculopathy. No red flags. Failed conservative management. Initial imaging. As with acute TBP, few studies support or refute imaging for patients with subacute or chronic midback pain without neurologic symptoms. However, as with LBP, imaging is typically not considered useful in this setting [6,7]. For patients with subacute (4-12 weeks duration) or chronic (>12 weeks duration) TBP without red flags or prior management, conservative therapy should still be considered first-line [25]. Bone Scan Whole Body There is no relevant literature to support the use of bone scans whole body in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scans with SPECT or SPECT/CT thoracic spine in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. CT Myelography Thoracic Spine There is no relevant literature to support the use of CT myelography thoracic spine in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. | Thoracic Back Pain. MRI Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of MRI thoracic spine without and with IV contrast in the initial evaluation of acute uncomplicated TBP. MRI Thoracic Spine Without IV Contrast There is no relevant literature to support the use of MRI thoracic spine without IV contrast in the initial evaluation of acute uncomplicated TBP. Radiography Thoracic Spine There is no relevant literature to support the use of radiography in the initial evaluation of acute uncomplicated TBP. Variant 2: Adult. Subacute or chronic thoracic back pain without myelopathy or radiculopathy. No red flags. Failed conservative management. Initial imaging. As with acute TBP, few studies support or refute imaging for patients with subacute or chronic midback pain without neurologic symptoms. However, as with LBP, imaging is typically not considered useful in this setting [6,7]. For patients with subacute (4-12 weeks duration) or chronic (>12 weeks duration) TBP without red flags or prior management, conservative therapy should still be considered first-line [25]. Bone Scan Whole Body There is no relevant literature to support the use of bone scans whole body in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scans with SPECT or SPECT/CT thoracic spine in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. CT Myelography Thoracic Spine There is no relevant literature to support the use of CT myelography thoracic spine in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. | 3195158 |
acrac_3195158_4 | Thoracic Back Pain | CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. CT Thoracic Spine Without IV Contrast There is no relevant literature to support the use of CT thoracic spine without IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. MRI Thoracic Spine With IV Contrast There is no relevant literature to support the use of MRI thoracic spine with IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. MRI Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of MRI thoracic spine without and with IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. MRI Thoracic Spine Without IV Contrast There is no relevant literature to support the use of MRI thoracic spine without IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. Radiography Thoracic Spine There is no relevant literature to support the use of radiography in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. Thoracic Back Pain Variant 3: Adult. Thoracic back pain with myelopathy or radiculopathy. Initial imaging. The goal of imaging is to identify potential actionable pain generators that could be targeted for medical treatment, intervention, or surgery. MRI of the thoracic spine has become the initial imaging modality of choice in these patients [13,26,27]. | Thoracic Back Pain. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. CT Thoracic Spine Without IV Contrast There is no relevant literature to support the use of CT thoracic spine without IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. MRI Thoracic Spine With IV Contrast There is no relevant literature to support the use of MRI thoracic spine with IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. MRI Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of MRI thoracic spine without and with IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. MRI Thoracic Spine Without IV Contrast There is no relevant literature to support the use of MRI thoracic spine without IV contrast in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. Radiography Thoracic Spine There is no relevant literature to support the use of radiography in the initial evaluation of subacute or chronic TBP without red flags or neurologic deficits. Thoracic Back Pain Variant 3: Adult. Thoracic back pain with myelopathy or radiculopathy. Initial imaging. The goal of imaging is to identify potential actionable pain generators that could be targeted for medical treatment, intervention, or surgery. MRI of the thoracic spine has become the initial imaging modality of choice in these patients [13,26,27]. | 3195158 |
acrac_3195158_5 | Thoracic Back Pain | Thoracic myelopathy is most commonly due to compressive etiologies, including structural causes resulting in spinal canal stenosis, cord compression/deformity, or other inflammatory, infectious, vascular, or neoplastic etiologies [28]. Spinal stenosis is a common cause of myelopathy, typically from disc herniations (including giant calcified disc herniations), usually below T7, facet arthropathy, or ligamentum flavum ossification [29]. Symptomatic thoracic disc herniations are more common in patients in their third to fifth decades of life and, in more than one-third of patients, are associated with a history of trauma. On imaging, these are often calcified (20%- 65%) and sometimes intradural (5%-10%) [30]. Patients with symptomatic thoracic disc herniations may have thoracic midback pain (76%), motor/sensory deficit (61%), spasticity/hyperreflexia (58%), positive Babinski sign (55%), or bladder dysfunction (24%). Symptomatic thoracic disc herniations requiring surgery are rare, accounting for 1% to 2% of all discectomies [31]. Indication for surgery is usually severe, intractable pain, or progressive/severe myelopathy. Thoracic radiculopathy is most commonly due to mechanical nerve root compression from degenerative, metabolic, infectious, or neoplastic causes. Bone Scan Whole Body There is no relevant literature to support the use of whole-body bone scans in the initial imaging of TBP and myelopathy or radiculopathy. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scan with SPECT or SPECT/CT in the initial imaging of TBP and myelopathy or radiculopathy. CT Myelography Thoracic Spine CT myelography of the thoracic spine can be useful in assessing the patency of the spinal canal/thecal sac. | Thoracic Back Pain. Thoracic myelopathy is most commonly due to compressive etiologies, including structural causes resulting in spinal canal stenosis, cord compression/deformity, or other inflammatory, infectious, vascular, or neoplastic etiologies [28]. Spinal stenosis is a common cause of myelopathy, typically from disc herniations (including giant calcified disc herniations), usually below T7, facet arthropathy, or ligamentum flavum ossification [29]. Symptomatic thoracic disc herniations are more common in patients in their third to fifth decades of life and, in more than one-third of patients, are associated with a history of trauma. On imaging, these are often calcified (20%- 65%) and sometimes intradural (5%-10%) [30]. Patients with symptomatic thoracic disc herniations may have thoracic midback pain (76%), motor/sensory deficit (61%), spasticity/hyperreflexia (58%), positive Babinski sign (55%), or bladder dysfunction (24%). Symptomatic thoracic disc herniations requiring surgery are rare, accounting for 1% to 2% of all discectomies [31]. Indication for surgery is usually severe, intractable pain, or progressive/severe myelopathy. Thoracic radiculopathy is most commonly due to mechanical nerve root compression from degenerative, metabolic, infectious, or neoplastic causes. Bone Scan Whole Body There is no relevant literature to support the use of whole-body bone scans in the initial imaging of TBP and myelopathy or radiculopathy. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scan with SPECT or SPECT/CT in the initial imaging of TBP and myelopathy or radiculopathy. CT Myelography Thoracic Spine CT myelography of the thoracic spine can be useful in assessing the patency of the spinal canal/thecal sac. | 3195158 |
acrac_3195158_6 | Thoracic Back Pain | CT myelography may also be complementary to MRI for identifying and differentiating between certain causes of myelopathy, such as ventral cord herniation versus dorsal thoracic arachnoid web or cyst, and also for presurgical or preradiation treatment planning due to its high detail and exquisite resolution of the contents of the spinal canal [32]. CT myelography has the disadvantage of requiring lumbar puncture for intrathecal injection of myelographic contrast. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging of TBP and myelopathy or radiculopathy. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial imaging of TBP and myelopathy or radiculopathy. CT Thoracic Spine Without IV Contrast There is no relevant literature to support the use of CT thoracic spine without IV contrast in the initial imaging of TBP and myelopathy or radiculopathy. However, CT thoracic spine without IV contrast may be useful for preoperative planning. CT delineates osseous structures and anatomy with high resolution and can aid in trajectory planning for hardware fixation. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging of TBP and myelopathy or radiculopathy. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast. Thoracic Back Pain | Thoracic Back Pain. CT myelography may also be complementary to MRI for identifying and differentiating between certain causes of myelopathy, such as ventral cord herniation versus dorsal thoracic arachnoid web or cyst, and also for presurgical or preradiation treatment planning due to its high detail and exquisite resolution of the contents of the spinal canal [32]. CT myelography has the disadvantage of requiring lumbar puncture for intrathecal injection of myelographic contrast. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging of TBP and myelopathy or radiculopathy. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial imaging of TBP and myelopathy or radiculopathy. CT Thoracic Spine Without IV Contrast There is no relevant literature to support the use of CT thoracic spine without IV contrast in the initial imaging of TBP and myelopathy or radiculopathy. However, CT thoracic spine without IV contrast may be useful for preoperative planning. CT delineates osseous structures and anatomy with high resolution and can aid in trajectory planning for hardware fixation. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging of TBP and myelopathy or radiculopathy. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast. Thoracic Back Pain | 3195158 |
acrac_3195158_7 | Thoracic Back Pain | MRI Thoracic Spine Without and With IV Contrast MRI thoracic spine without and with IV contrast may be the preferred initial study of choice in patients with TBP and myelopathy/radiculopathy when underlying malignancy, infection, or inflammation is clinically suspected. MRI Thoracic Spine Without IV Contrast MRI thoracic spine without IV contrast may be useful as an initial study of choice in patients with TBP and myelopathy/radiculopathy when structural/mechanical causes of compressive myelopathy or radiculopathy are clinically suspected. MRI thoracic spine without IV contrast is most useful in evaluating compressive myelopathy or radiculopathy because of its ability to accurately depict soft tissue pathology, assess vertebral marrow, and assess the spinal canal patency [20]. Heavily T2-weighted sequences such as CISS/FIESTA may be helpful to assess for structural etiologies such as dorsal thoracic arachnoid webs or for reducing metallic artifacts in patients with thoracic spinal hardware [33]. Radiography Thoracic Spine There is no relevant literature to support the use of thoracic spine radiography in the initial evaluation of patients with TBP and myelopathy. Radiography alone is not usually sufficient for diagnosing the specific pain generator in these patients or for guiding surgical or interventional options without MRI and/or CT imaging. However, it can provide complementary information that can be helpful in treatment planning, including for presurgical planning and postoperative assessment [11]. Variant 4: Adult. Thoracic back pain without or with myelopathy or radiculopathy. One or more of the following: low-velocity trauma, osteoporosis, elderly individual, or chronic steroid use. Initial imaging. Elderly (>65 years of age) individuals, those with known osteoporosis, prior benign nontraumatic compression fracture, or chronic steroid use are at risk for additional compression fractures even with minimal to no trauma [34,35]. | Thoracic Back Pain. MRI Thoracic Spine Without and With IV Contrast MRI thoracic spine without and with IV contrast may be the preferred initial study of choice in patients with TBP and myelopathy/radiculopathy when underlying malignancy, infection, or inflammation is clinically suspected. MRI Thoracic Spine Without IV Contrast MRI thoracic spine without IV contrast may be useful as an initial study of choice in patients with TBP and myelopathy/radiculopathy when structural/mechanical causes of compressive myelopathy or radiculopathy are clinically suspected. MRI thoracic spine without IV contrast is most useful in evaluating compressive myelopathy or radiculopathy because of its ability to accurately depict soft tissue pathology, assess vertebral marrow, and assess the spinal canal patency [20]. Heavily T2-weighted sequences such as CISS/FIESTA may be helpful to assess for structural etiologies such as dorsal thoracic arachnoid webs or for reducing metallic artifacts in patients with thoracic spinal hardware [33]. Radiography Thoracic Spine There is no relevant literature to support the use of thoracic spine radiography in the initial evaluation of patients with TBP and myelopathy. Radiography alone is not usually sufficient for diagnosing the specific pain generator in these patients or for guiding surgical or interventional options without MRI and/or CT imaging. However, it can provide complementary information that can be helpful in treatment planning, including for presurgical planning and postoperative assessment [11]. Variant 4: Adult. Thoracic back pain without or with myelopathy or radiculopathy. One or more of the following: low-velocity trauma, osteoporosis, elderly individual, or chronic steroid use. Initial imaging. Elderly (>65 years of age) individuals, those with known osteoporosis, prior benign nontraumatic compression fracture, or chronic steroid use are at risk for additional compression fractures even with minimal to no trauma [34,35]. | 3195158 |
acrac_3195158_8 | Thoracic Back Pain | Patients with low-velocity trauma, and without risk factors for osteoporosis, may not need dedicated thoracic spine imaging if asymptomatic. Bone Scan Whole Body Whole-body bone scans may be helpful in the setting of compression fracture(s) to help identify fracture acuity and to appropriately select patients for intervention [36], particularly if MRI cannot be safely/easily obtained. Bone Scan with SPECT or SPECT/CT Thoracic Spine Bone scan with SPECT or SPECT/CT may be helpful in the setting of compression fracture(s) to help identify fracture acuity and to appropriately select patients for intervention [36]. CT Myelography Thoracic Spine There is no relevant literature to support the use of CT myelography thoracic spine in the initial imaging assessment of this group. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging assessment of this group. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial imaging assessment of this group. CT Thoracic Spine Without IV Contrast CT thoracic spine without IV contrast may be useful as an initial study in the emergency room setting or for presurgical planning, particularly if radiographs are negative [36]. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging assessment of this group. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast. Thoracic Back Pain | Thoracic Back Pain. Patients with low-velocity trauma, and without risk factors for osteoporosis, may not need dedicated thoracic spine imaging if asymptomatic. Bone Scan Whole Body Whole-body bone scans may be helpful in the setting of compression fracture(s) to help identify fracture acuity and to appropriately select patients for intervention [36], particularly if MRI cannot be safely/easily obtained. Bone Scan with SPECT or SPECT/CT Thoracic Spine Bone scan with SPECT or SPECT/CT may be helpful in the setting of compression fracture(s) to help identify fracture acuity and to appropriately select patients for intervention [36]. CT Myelography Thoracic Spine There is no relevant literature to support the use of CT myelography thoracic spine in the initial imaging assessment of this group. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging assessment of this group. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial imaging assessment of this group. CT Thoracic Spine Without IV Contrast CT thoracic spine without IV contrast may be useful as an initial study in the emergency room setting or for presurgical planning, particularly if radiographs are negative [36]. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging assessment of this group. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast. Thoracic Back Pain | 3195158 |
acrac_3195158_9 | Thoracic Back Pain | MRI Thoracic Spine Without and With IV Contrast MRI thoracic spine without and with IV contrast is not typically performed as an initial study in this group unless there is concern for underlying neoplasm, infection, or inflammation. MRI Thoracic Spine Without IV Contrast MRI thoracic spine without IV contrast may be useful as an initial study in this group due to its excellent soft tissue resolution, particularly if there is concern for soft tissue or neurologic compressive injury, to identify a compression fracture (even if radiographs are negative), or to plan intervention (identify marrow edema) [36]. Radiography Thoracic Spine Radiography may be useful as an initial screening study in TBP with risk factors for osteoporotic fractures in patients without neurologic deficits [35]. However, it should be noted that thoracic vertebral body fractures seen on radiographs may be difficult to estimate in terms of chronicity without priors to compare to. In those cases, MRI or bone scan may be needed to age the fracture acuity. Bone Scan Whole Body There is no relevant literature to support the use of whole-body bone scan in the initial imaging assessment of this group. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scans with SPECT or SPECT/CT in the initial imaging assessment of this group. CT Myelography Thoracic Spine CT myelography of the thoracic spine may be helpful in patients or for treatment planning (surgery, radiation). CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging assessment of this group. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial imaging assessment of this group. | Thoracic Back Pain. MRI Thoracic Spine Without and With IV Contrast MRI thoracic spine without and with IV contrast is not typically performed as an initial study in this group unless there is concern for underlying neoplasm, infection, or inflammation. MRI Thoracic Spine Without IV Contrast MRI thoracic spine without IV contrast may be useful as an initial study in this group due to its excellent soft tissue resolution, particularly if there is concern for soft tissue or neurologic compressive injury, to identify a compression fracture (even if radiographs are negative), or to plan intervention (identify marrow edema) [36]. Radiography Thoracic Spine Radiography may be useful as an initial screening study in TBP with risk factors for osteoporotic fractures in patients without neurologic deficits [35]. However, it should be noted that thoracic vertebral body fractures seen on radiographs may be difficult to estimate in terms of chronicity without priors to compare to. In those cases, MRI or bone scan may be needed to age the fracture acuity. Bone Scan Whole Body There is no relevant literature to support the use of whole-body bone scan in the initial imaging assessment of this group. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scans with SPECT or SPECT/CT in the initial imaging assessment of this group. CT Myelography Thoracic Spine CT myelography of the thoracic spine may be helpful in patients or for treatment planning (surgery, radiation). CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging assessment of this group. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial imaging assessment of this group. | 3195158 |
acrac_3195158_10 | Thoracic Back Pain | CT Thoracic Spine Without IV Contrast CT thoracic spine without IV contrast may be helpful for presurgical planning or to delineate the osseous anatomy, particularly if there is osseous destruction [37]. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging assessment of this group. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast. MRI Thoracic Spine Without and With IV Contrast MRI without and with IV contrast is the initial imaging modality of choice in patients with TBP and suspected neoplasm or infection [36,38-42]. Thoracic Back Pain MRI Thoracic Spine Without IV Contrast MRI without IV contrast may be useful in this setting to identify marrow replacing lesions, osseous destruction, canal compromise, and cord signal abnormality. However, the addition of postcontrast sequences would be more sensitive in identifying thoracic spinal infection and its complications, assessing small marrow replacing lesions, and identifying intradural disease [39-44]. Radiography Thoracic Spine Radiographs have low sensitivity but may be useful in the urgent/emergent setting to identify osseous destruction or change in alignment in patients with TBP and suspected infection or neoplasm [45]. Variant 6: Adult. Thoracic back pain without or with myelopathy or radiculopathy. Radiograph shows bone destruction or fracture or spinal deformity. Next imaging study. In patients with TBP and osseous destruction or spinal deformity the role of imaging is to delineate osseous detail and anatomy and assess the integrity of the soft tissue and neural structures, particularly that of the spinal canal. | Thoracic Back Pain. CT Thoracic Spine Without IV Contrast CT thoracic spine without IV contrast may be helpful for presurgical planning or to delineate the osseous anatomy, particularly if there is osseous destruction [37]. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging assessment of this group. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast. MRI Thoracic Spine Without and With IV Contrast MRI without and with IV contrast is the initial imaging modality of choice in patients with TBP and suspected neoplasm or infection [36,38-42]. Thoracic Back Pain MRI Thoracic Spine Without IV Contrast MRI without IV contrast may be useful in this setting to identify marrow replacing lesions, osseous destruction, canal compromise, and cord signal abnormality. However, the addition of postcontrast sequences would be more sensitive in identifying thoracic spinal infection and its complications, assessing small marrow replacing lesions, and identifying intradural disease [39-44]. Radiography Thoracic Spine Radiographs have low sensitivity but may be useful in the urgent/emergent setting to identify osseous destruction or change in alignment in patients with TBP and suspected infection or neoplasm [45]. Variant 6: Adult. Thoracic back pain without or with myelopathy or radiculopathy. Radiograph shows bone destruction or fracture or spinal deformity. Next imaging study. In patients with TBP and osseous destruction or spinal deformity the role of imaging is to delineate osseous detail and anatomy and assess the integrity of the soft tissue and neural structures, particularly that of the spinal canal. | 3195158 |
acrac_3195158_11 | Thoracic Back Pain | Additionally, if spinal hardware is present, assessing hardware integrity and position is also a common indication for imaging. More than one imaging modality may be indicated for diagnosis and treatment planning. Bone Scan Whole Body There is no relevant literature to support the use of whole body bone scans in the initial imaging assessment of this group. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scan with SPECT or SPECT/CT in the initial imaging assessment of this group. CT Myelography Thoracic Spine CT myelography may be useful in this setting in patients with spinal hardware. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging assessment of this group. CT Thoracic Spine Without and With IV Contrast CT thoracic spine without and with IV contrast may be useful in this clinical scenario. CT Thoracic Spine Without IV Contrast In patients with TBP with or without myelopathy or radiculopathy when there is evidence of osseous destruction or spinal deformity on radiographs, both MRI and CT may be useful as an initial imaging modality [11,46]. CT can better depict the osseous detail, and MRI is more useful for assessing the integrity of the soft tissue and neural structures, particularly that of the spinal canal. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging assessment of this group. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast. | Thoracic Back Pain. Additionally, if spinal hardware is present, assessing hardware integrity and position is also a common indication for imaging. More than one imaging modality may be indicated for diagnosis and treatment planning. Bone Scan Whole Body There is no relevant literature to support the use of whole body bone scans in the initial imaging assessment of this group. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is no relevant literature to support the use of bone scan with SPECT or SPECT/CT in the initial imaging assessment of this group. CT Myelography Thoracic Spine CT myelography may be useful in this setting in patients with spinal hardware. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging assessment of this group. CT Thoracic Spine Without and With IV Contrast CT thoracic spine without and with IV contrast may be useful in this clinical scenario. CT Thoracic Spine Without IV Contrast In patients with TBP with or without myelopathy or radiculopathy when there is evidence of osseous destruction or spinal deformity on radiographs, both MRI and CT may be useful as an initial imaging modality [11,46]. CT can better depict the osseous detail, and MRI is more useful for assessing the integrity of the soft tissue and neural structures, particularly that of the spinal canal. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging assessment of this group. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast. | 3195158 |
acrac_3195158_12 | Thoracic Back Pain | MRI Thoracic Spine Without and With IV Contrast MRI thoracic spine without and with IV contrast may be useful as an imaging study in patients with TBP and evidence of spinal deformity or osseous destruction on radiography, particularly if there is concern for infection or neoplasm [44]. MRI Thoracic Spine Without IV Contrast MRI without IV contrast may be useful in this setting to identify marrow replacing lesions, osseous destruction, canal compromise, and cord signal abnormality [27]. However, the addition of postcontrast sequences would be more sensitive in identifying thoracic spinal infection and its complications, assessing small marrow replacing lesions, and identifying intradural disease. Thoracic Back Pain Variant 7: Adult. Thoracic back pain without or with myelopathy or radiculopathy. Post thoracic spine surgery. Follow-up imaging. In patients with TBP and a history of spinal fixation, imaging plays an important role in assessing hardware position and integrity, assessing spinal alignment, assessing fusion, identifying findings suspicious for infection, and assessing for postoperative complications, including, but not limited to, postoperative collections, scarring, adjacent segment degeneration, and spinal deformity [47]. Several imaging modalities may be useful and complementary in the initial assessment of patients with TBP and a history of instrumented spinal fixation [43,45,47]. Bone Scan Whole Body There is no relevant literature to support the use of whole-body bone scans in the initial imaging assessment of this group. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is limited literature to support the use of bone scan with SPECT or SPECT/CT thoracic spine in the initial imaging assessment of this group. CT Myelography Thoracic Spine CT myelography may also be helpful in patients in whom a compressive etiology of their symptoms is clinically suspected. | Thoracic Back Pain. MRI Thoracic Spine Without and With IV Contrast MRI thoracic spine without and with IV contrast may be useful as an imaging study in patients with TBP and evidence of spinal deformity or osseous destruction on radiography, particularly if there is concern for infection or neoplasm [44]. MRI Thoracic Spine Without IV Contrast MRI without IV contrast may be useful in this setting to identify marrow replacing lesions, osseous destruction, canal compromise, and cord signal abnormality [27]. However, the addition of postcontrast sequences would be more sensitive in identifying thoracic spinal infection and its complications, assessing small marrow replacing lesions, and identifying intradural disease. Thoracic Back Pain Variant 7: Adult. Thoracic back pain without or with myelopathy or radiculopathy. Post thoracic spine surgery. Follow-up imaging. In patients with TBP and a history of spinal fixation, imaging plays an important role in assessing hardware position and integrity, assessing spinal alignment, assessing fusion, identifying findings suspicious for infection, and assessing for postoperative complications, including, but not limited to, postoperative collections, scarring, adjacent segment degeneration, and spinal deformity [47]. Several imaging modalities may be useful and complementary in the initial assessment of patients with TBP and a history of instrumented spinal fixation [43,45,47]. Bone Scan Whole Body There is no relevant literature to support the use of whole-body bone scans in the initial imaging assessment of this group. Bone Scan with SPECT or SPECT/CT Thoracic Spine There is limited literature to support the use of bone scan with SPECT or SPECT/CT thoracic spine in the initial imaging assessment of this group. CT Myelography Thoracic Spine CT myelography may also be helpful in patients in whom a compressive etiology of their symptoms is clinically suspected. | 3195158 |
acrac_3195158_13 | Thoracic Back Pain | CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging assessment of this group. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial imaging assessment of this group. CT Thoracic Spine Without IV Contrast CT thoracic spine without IV contrast may be useful in assessing the integrity of fusion, identifying hardware position and integrity, and assessing alignment. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging assessment of this group. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast. MRI Thoracic Spine Without and With IV Contrast MRI thoracic spine without and with IV contrast may be helpful in assessing for postoperative infection, hematoma, postoperative collections, or canal compromise. Many of these patients may benefit from scanning on mid field or 1.5T MRI scanners with metallic susceptibility artifact reduction protocols [46,47]. MRI Thoracic Spine Without IV Contrast MRI thoracic spine without IV contrast may help assess for postoperative hematoma or other collections, neurologic injury, residual foramina or canal stenosis, or cord compression. Radiography Thoracic Spine Radiographs may be useful for assessing the integrity of fusion, confirming hardware position and integrity, identifying adjacent level degeneration, and assessing alignment. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch. acr.org/list. | Thoracic Back Pain. CT Thoracic Spine With IV Contrast There is no relevant literature to support the use of CT thoracic spine with IV contrast in the initial imaging assessment of this group. CT Thoracic Spine Without and With IV Contrast There is no relevant literature to support the use of CT thoracic spine without and with IV contrast in the initial imaging assessment of this group. CT Thoracic Spine Without IV Contrast CT thoracic spine without IV contrast may be useful in assessing the integrity of fusion, identifying hardware position and integrity, and assessing alignment. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT skull base to mid-thigh in the initial imaging assessment of this group. MRI Thoracic Spine With IV Contrast MRI thoracic spine with IV contrast is not typically performed independently as an initial study, because its interpretation is most informative when correlated with standard noncontrast sequences included in MRI thoracic spine with and without IV contrast. MRI Thoracic Spine Without and With IV Contrast MRI thoracic spine without and with IV contrast may be helpful in assessing for postoperative infection, hematoma, postoperative collections, or canal compromise. Many of these patients may benefit from scanning on mid field or 1.5T MRI scanners with metallic susceptibility artifact reduction protocols [46,47]. MRI Thoracic Spine Without IV Contrast MRI thoracic spine without IV contrast may help assess for postoperative hematoma or other collections, neurologic injury, residual foramina or canal stenosis, or cord compression. Radiography Thoracic Spine Radiographs may be useful for assessing the integrity of fusion, confirming hardware position and integrity, identifying adjacent level degeneration, and assessing alignment. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch. acr.org/list. | 3195158 |
acrac_3099847_0 | Staging of Pancreatic Ductal Adenocarcinoma | Introduction/Background Prevalence, Etiology, Treatment, and Prognosis According to the American Cancer Society, the number of new pancreatic cancer cases estimated in the United States in 2017 is 53,670 [1]. The estimated number of deaths is 43,090 in 2017, with pancreatic adenocarcinoma remaining the fourth leading cause of cancer-related death in the United States. Difficulty in early detection and lack of effective screening methods invariably results in an advanced stage at presentation and poor prognosis. Associated risk factors include tobacco use (20% of patients), family history of pancreatic cancer (two or more first-degree relatives with pancreatic cancer reported in 10% of patients), chronic pancreatitis, diabetes, obesity, hereditary pancreatitis [2-4] and genetic alterations such as BRCA1, BRCA2, PALB2, p16 gene mutations, Lynch syndrome, and Peutz-Jeghers syndrome [5,6]. Screening is not currently recommended for the general population (US Preventive Services Task Force gives a D recommendation) [7]. However, some have suggested that screening patients at high risk of developing pancreatic cancer is feasible, while acknowledging that data for cost- effectiveness and benefit are still required [8]. To date, the most suitable imaging technology for such screening is unclear [5]. No specific tumor markers for pancreatic cancer exist, and although most patients will demonstrate elevation in serum cancer antigen 19-9, this has low specificity and is more often used to indicate disease progression. Pancreatic cancer develops insidiously in the exocrine cells, and as such, early disease is often asymptomatic or presents with vague symptoms such as loss of appetite, fatigue, and general malaise. Consequently, 80% to 85% of patients present with advanced disease without the option of surgical resection [9]. Overall survival for pancreatic cancer is 28% after 1 year and 7% after 5 years [1]. | Staging of Pancreatic Ductal Adenocarcinoma. Introduction/Background Prevalence, Etiology, Treatment, and Prognosis According to the American Cancer Society, the number of new pancreatic cancer cases estimated in the United States in 2017 is 53,670 [1]. The estimated number of deaths is 43,090 in 2017, with pancreatic adenocarcinoma remaining the fourth leading cause of cancer-related death in the United States. Difficulty in early detection and lack of effective screening methods invariably results in an advanced stage at presentation and poor prognosis. Associated risk factors include tobacco use (20% of patients), family history of pancreatic cancer (two or more first-degree relatives with pancreatic cancer reported in 10% of patients), chronic pancreatitis, diabetes, obesity, hereditary pancreatitis [2-4] and genetic alterations such as BRCA1, BRCA2, PALB2, p16 gene mutations, Lynch syndrome, and Peutz-Jeghers syndrome [5,6]. Screening is not currently recommended for the general population (US Preventive Services Task Force gives a D recommendation) [7]. However, some have suggested that screening patients at high risk of developing pancreatic cancer is feasible, while acknowledging that data for cost- effectiveness and benefit are still required [8]. To date, the most suitable imaging technology for such screening is unclear [5]. No specific tumor markers for pancreatic cancer exist, and although most patients will demonstrate elevation in serum cancer antigen 19-9, this has low specificity and is more often used to indicate disease progression. Pancreatic cancer develops insidiously in the exocrine cells, and as such, early disease is often asymptomatic or presents with vague symptoms such as loss of appetite, fatigue, and general malaise. Consequently, 80% to 85% of patients present with advanced disease without the option of surgical resection [9]. Overall survival for pancreatic cancer is 28% after 1 year and 7% after 5 years [1]. | 3099847 |
acrac_3099847_1 | Staging of Pancreatic Ductal Adenocarcinoma | Localized pancreatic cancer, reportedly diagnosed in 9% of patients, is associated with a 26% 5-year survival. Distant stage disease at diagnosis is associated with only a 15% 1-year and 2% 5-year survival [1]. Given the poor prognosis, accurate staging is essential and pivotal to patient management decisions that are decided through a multidisciplinary approach [5]. Imaging plays a critical role in pancreatic cancer staging and therapeutic decision process. The imaging armamentarium used to evaluate pancreatic cancer includes multidetector computed tomography (MDCT), magnetic resonance imaging (MRI), endoscopic ultrasound (EUS), and fluorine-18-2-fluoro-2-deoxy- D-glucose positron emission tomography (FDG-PET)/CT. aPrincipal Author, University of Texas MD Anderson Cancer Center, Houston, Texas. bResearch author, University of Texas MD Anderson Cancer Center, Houston, Texas. cPanel Chair, Johns Hopkins University School of Medicine, Baltimore, Maryland. dMemorial Sloan Kettering Cancer Center, New York, New York; American College of Surgeons. eUniversity of Arizona, Banner University Medical Center, Tucson, Arizona. fMontefiore Medical Center, Bronx, New York. gColumbia University, New York, New York; American Gastroenterological Association. hUniversity of Florida College of Medicine, Gainesville, Florida. iNew York University Medical Center, New York, New York. jNorthwestern University, Chicago, Illinois. kUniversity of Texas MD Anderson Cancer Center, Houston, Texas. lUniversity of Alabama Medical Center, Birmingham, Alabama. mThe Warren Alpert School of Medicine at Brown University, Providence, Rhode Island. nUniversity of Illinois College of Medicine, Chicago, Illinois; American College of Physicians. oSpecialty Chair, University of Washington, Seattle, Washington. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. | Staging of Pancreatic Ductal Adenocarcinoma. Localized pancreatic cancer, reportedly diagnosed in 9% of patients, is associated with a 26% 5-year survival. Distant stage disease at diagnosis is associated with only a 15% 1-year and 2% 5-year survival [1]. Given the poor prognosis, accurate staging is essential and pivotal to patient management decisions that are decided through a multidisciplinary approach [5]. Imaging plays a critical role in pancreatic cancer staging and therapeutic decision process. The imaging armamentarium used to evaluate pancreatic cancer includes multidetector computed tomography (MDCT), magnetic resonance imaging (MRI), endoscopic ultrasound (EUS), and fluorine-18-2-fluoro-2-deoxy- D-glucose positron emission tomography (FDG-PET)/CT. aPrincipal Author, University of Texas MD Anderson Cancer Center, Houston, Texas. bResearch author, University of Texas MD Anderson Cancer Center, Houston, Texas. cPanel Chair, Johns Hopkins University School of Medicine, Baltimore, Maryland. dMemorial Sloan Kettering Cancer Center, New York, New York; American College of Surgeons. eUniversity of Arizona, Banner University Medical Center, Tucson, Arizona. fMontefiore Medical Center, Bronx, New York. gColumbia University, New York, New York; American Gastroenterological Association. hUniversity of Florida College of Medicine, Gainesville, Florida. iNew York University Medical Center, New York, New York. jNorthwestern University, Chicago, Illinois. kUniversity of Texas MD Anderson Cancer Center, Houston, Texas. lUniversity of Alabama Medical Center, Birmingham, Alabama. mThe Warren Alpert School of Medicine at Brown University, Providence, Rhode Island. nUniversity of Illinois College of Medicine, Chicago, Illinois; American College of Physicians. oSpecialty Chair, University of Washington, Seattle, Washington. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. | 3099847 |
acrac_3099847_2 | Staging of Pancreatic Ductal Adenocarcinoma | Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] Staging of Pancreatic Ductal Adenocarcinoma Key determinants of tumor stage can be summarized as follows: Stage IV disease is the presence of any distant metastases, stage III disease is any T4 disease, stage IIA disease is T3 disease with no distant metastases or nodal involvement, stage IIB disease is T1 through T3 disease with nodal involvement, stage IA is T1 disease without nodal involvement, and stage IB is T2 disease without nodal involvement. Treatment options include surgery, radiation therapy, and chemotherapy. Radical surgical resection offers potentially curative therapy, though it is seldom achieved. Furthermore, the general procedure-related morbidity rate is high at 20% and mortality rate is 1% to 4% [10,11]. Less than 20% of patients are candidates for surgery. For those undergoing surgery, the cancer is often too extensive for removal. Adjuvant chemotherapy with gemcitabine or chemoradiation after surgery has been reported by some to improve survival, but this is controversial due to conflicting published results [12-15]. Use of combination systemic therapy with gemcitabine and the targeted anticancer drug erlotinib, has been suggested to slightly increase survival in patients with advanced cancer [1]. Cure rates are highest for tumors that are truly localized to the pancreas (without extension beyond the pancreatic capsule or lymph node metastases). Surgical resection of small, localized tumors, (measuring <2 cm in maximum diameter), are associated with a survival rate of 18% to 24% [16]. Decisive factors determining tumor resectability include presence of distant metastases, and vascular involvement particularly the celiac axis, superior mesenteric artery (SMA), superior mesenteric vein (SMV), and portal vein (PV). | Staging of Pancreatic Ductal Adenocarcinoma. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] Staging of Pancreatic Ductal Adenocarcinoma Key determinants of tumor stage can be summarized as follows: Stage IV disease is the presence of any distant metastases, stage III disease is any T4 disease, stage IIA disease is T3 disease with no distant metastases or nodal involvement, stage IIB disease is T1 through T3 disease with nodal involvement, stage IA is T1 disease without nodal involvement, and stage IB is T2 disease without nodal involvement. Treatment options include surgery, radiation therapy, and chemotherapy. Radical surgical resection offers potentially curative therapy, though it is seldom achieved. Furthermore, the general procedure-related morbidity rate is high at 20% and mortality rate is 1% to 4% [10,11]. Less than 20% of patients are candidates for surgery. For those undergoing surgery, the cancer is often too extensive for removal. Adjuvant chemotherapy with gemcitabine or chemoradiation after surgery has been reported by some to improve survival, but this is controversial due to conflicting published results [12-15]. Use of combination systemic therapy with gemcitabine and the targeted anticancer drug erlotinib, has been suggested to slightly increase survival in patients with advanced cancer [1]. Cure rates are highest for tumors that are truly localized to the pancreas (without extension beyond the pancreatic capsule or lymph node metastases). Surgical resection of small, localized tumors, (measuring <2 cm in maximum diameter), are associated with a survival rate of 18% to 24% [16]. Decisive factors determining tumor resectability include presence of distant metastases, and vascular involvement particularly the celiac axis, superior mesenteric artery (SMA), superior mesenteric vein (SMV), and portal vein (PV). | 3099847 |
acrac_3099847_3 | Staging of Pancreatic Ductal Adenocarcinoma | Motivation in efforts to increase surgical candidates is consequent to complete tumor resection being the sole option for cure. Close collaborative efforts between surgeons, oncologists, radiation oncologists, and diagnostic imaging has resulted in the development of resectable and borderline resectable disease criteria over the last decade. Increasingly sophisticated surgical techniques, including complex vascular reconstruction and use of neoadjuvant and adjuvant therapies have increased demand of more detailed and specific radiological interpretation of disease extent. Surgical definition of borderline resectable pancreatic cancer is based on five important observations: 1) long-term survival necessitates complete resection of the primary tumor and regional lymph nodes; 2) negative resection margins are less likely with increasing tumor involvement of the SMV-PV and SMA; 3) SMV-PV and hepatic artery resection (not SMA) at pancreatectomy has been associated with acceptable outcomes; 4) administration of conventional cytotoxic agents rarely results in down-staging locally advanced pancreatic cancer; and 5) tumor response to neoadjuvant chemotherapy and chemoradiation may be indicative of favorable tumor physiology and biology, and thus used to select patients who may benefit from aggressive surgery [17-25]. | Staging of Pancreatic Ductal Adenocarcinoma. Motivation in efforts to increase surgical candidates is consequent to complete tumor resection being the sole option for cure. Close collaborative efforts between surgeons, oncologists, radiation oncologists, and diagnostic imaging has resulted in the development of resectable and borderline resectable disease criteria over the last decade. Increasingly sophisticated surgical techniques, including complex vascular reconstruction and use of neoadjuvant and adjuvant therapies have increased demand of more detailed and specific radiological interpretation of disease extent. Surgical definition of borderline resectable pancreatic cancer is based on five important observations: 1) long-term survival necessitates complete resection of the primary tumor and regional lymph nodes; 2) negative resection margins are less likely with increasing tumor involvement of the SMV-PV and SMA; 3) SMV-PV and hepatic artery resection (not SMA) at pancreatectomy has been associated with acceptable outcomes; 4) administration of conventional cytotoxic agents rarely results in down-staging locally advanced pancreatic cancer; and 5) tumor response to neoadjuvant chemotherapy and chemoradiation may be indicative of favorable tumor physiology and biology, and thus used to select patients who may benefit from aggressive surgery [17-25]. | 3099847 |
acrac_3099847_4 | Staging of Pancreatic Ductal Adenocarcinoma | Overview of Imaging Modalities Radiologic evaluation of patients with pancreatic cancer for staging should assess tumor size, extension of tumor beyond the pancreas including adjacent significant vasculature (namely the SMA, celiac artery, common hepatic artery, and splenic artery, hepatic arterial variants, and the main PV, splenic vein, SMV, and whether the tumor is extending to divisions of these veins, which would preclude placement of a graft), presence of regional adenopathy (especially nodes that may be beyond the surgical field and may be suspicious, based on size or morphology), and whether there is metastatic involvement of the liver, peritoneum, and lungs. CT CT At many institutions, contrast-enhanced MDCT is the preferred imaging technique for the staging of pancreatic cancer. It is quick, robust, and especially has superb spatial resolution. It is particularly useful for the assessment of tumor involvement of vascular structures. Imaging should be obtained as a multiphasic acquisition, with a late arterial phase timed to optimize peak enhancement of the pancreas (typically at 45-50 seconds after the start of contrast injection, depending on injection rate) to maximize visualization of the primary tumor, and a portal venous phase for optimum enhancement of venous structures and to maximize detectability of typically hypodense liver metastases (typically 70 seconds after the start of contrast injection) [28]. Many practices employ use of bolus tracking to optimize timing of the arterial and portal venous phase of enhancement. A recent study comparing 64-detector row MDCT and 3T MRI showed overall comparable sensitivities and specificities between the two modalities regarding resectability (CT sensitivity 87%, specificity 63% to 75%; MRI sensitivity 93%, specificity 50% to 75%) [11]. | Staging of Pancreatic Ductal Adenocarcinoma. Overview of Imaging Modalities Radiologic evaluation of patients with pancreatic cancer for staging should assess tumor size, extension of tumor beyond the pancreas including adjacent significant vasculature (namely the SMA, celiac artery, common hepatic artery, and splenic artery, hepatic arterial variants, and the main PV, splenic vein, SMV, and whether the tumor is extending to divisions of these veins, which would preclude placement of a graft), presence of regional adenopathy (especially nodes that may be beyond the surgical field and may be suspicious, based on size or morphology), and whether there is metastatic involvement of the liver, peritoneum, and lungs. CT CT At many institutions, contrast-enhanced MDCT is the preferred imaging technique for the staging of pancreatic cancer. It is quick, robust, and especially has superb spatial resolution. It is particularly useful for the assessment of tumor involvement of vascular structures. Imaging should be obtained as a multiphasic acquisition, with a late arterial phase timed to optimize peak enhancement of the pancreas (typically at 45-50 seconds after the start of contrast injection, depending on injection rate) to maximize visualization of the primary tumor, and a portal venous phase for optimum enhancement of venous structures and to maximize detectability of typically hypodense liver metastases (typically 70 seconds after the start of contrast injection) [28]. Many practices employ use of bolus tracking to optimize timing of the arterial and portal venous phase of enhancement. A recent study comparing 64-detector row MDCT and 3T MRI showed overall comparable sensitivities and specificities between the two modalities regarding resectability (CT sensitivity 87%, specificity 63% to 75%; MRI sensitivity 93%, specificity 50% to 75%) [11]. | 3099847 |
acrac_3099847_5 | Staging of Pancreatic Ductal Adenocarcinoma | A recent critical review of CT and MRI that was based on reports published between 1997 and 2009 also showed that CT and MRI performed comparably with both modalities showing improvement on more recent studies [29]. Notably, unenhanced CT has poor soft tissue contrast in comparison to MRI and therefore has marginal usefulness during staging. It should also be noted anecdotally, for the reasons given above, that in those institutions with MRI and CT capabilities, CT is typically the more used modality in the setting of staging pancreatic cancer. MRI Many MRI advances have been made in the past several years with regard to robustness of image quality, speed of image acquisition, and resolution in imaging. As noted above, MRI has been reported in a recent study to have a sensitivity of 93% and specificity of 50% to 75% for determination of resectability [11], and studies comparing state-of-the-art CT with state-of-the-art MRI report a similar overall performance [29]. MRI has inherently better soft tissue contrast than unenhanced CT enabling superior visualization of tumor without intravenous (IV) contrast administration. Although we could not identify studies specifically addressing noncontrast MRI staging sensitivity and specificity, MRI is preferable because techniques such as flow sensitive sequences and diffusion- weighted imaging provide valuable information when IV contrast is contraindicated. FDG-PET/CT There is considerable variation in how FDG-PET/CT is performed between institutions, with regard to the presence or absence of IV contrast, the presence or absence of oral contrast, as well as other parameters including slice thickness, and field-of-view. When performed without IV contrast, FDG-PET/CT has the same limitations as unenhanced CT with regard to local staging of the tumor. When performed with IV contrast, images are typically obtained at a single phase of contrast enhancement. | Staging of Pancreatic Ductal Adenocarcinoma. A recent critical review of CT and MRI that was based on reports published between 1997 and 2009 also showed that CT and MRI performed comparably with both modalities showing improvement on more recent studies [29]. Notably, unenhanced CT has poor soft tissue contrast in comparison to MRI and therefore has marginal usefulness during staging. It should also be noted anecdotally, for the reasons given above, that in those institutions with MRI and CT capabilities, CT is typically the more used modality in the setting of staging pancreatic cancer. MRI Many MRI advances have been made in the past several years with regard to robustness of image quality, speed of image acquisition, and resolution in imaging. As noted above, MRI has been reported in a recent study to have a sensitivity of 93% and specificity of 50% to 75% for determination of resectability [11], and studies comparing state-of-the-art CT with state-of-the-art MRI report a similar overall performance [29]. MRI has inherently better soft tissue contrast than unenhanced CT enabling superior visualization of tumor without intravenous (IV) contrast administration. Although we could not identify studies specifically addressing noncontrast MRI staging sensitivity and specificity, MRI is preferable because techniques such as flow sensitive sequences and diffusion- weighted imaging provide valuable information when IV contrast is contraindicated. FDG-PET/CT There is considerable variation in how FDG-PET/CT is performed between institutions, with regard to the presence or absence of IV contrast, the presence or absence of oral contrast, as well as other parameters including slice thickness, and field-of-view. When performed without IV contrast, FDG-PET/CT has the same limitations as unenhanced CT with regard to local staging of the tumor. When performed with IV contrast, images are typically obtained at a single phase of contrast enhancement. | 3099847 |
acrac_3099847_6 | Staging of Pancreatic Ductal Adenocarcinoma | Studies that have recently examined the role of FDG-PET/CT in the staging of pancreatic cancer have focused on its supplementary ability to detect additional distant metastases beyond those detected by conventional cross-sectional imaging of the abdomen and pelvis or chest, abdomen, and pelvis given the advantage that FDG-PET/CT is a whole-body examination [31]. Nodal staging is a limitation for any of the imaging modalities because of its relative insensitivity to micrometastases detection. Another challenge is the varying imaging criteria for identifying potential nodal involvement between studies. A recent study that used, as criterion for nodal involvement, a nodal short axis diameter of >5 mm or morphologic features of necrosis showed an accuracy of 55% to 60% for the detection of nodal metastatic disease, which is similar to findings seen on older studies regardless of criteria (44%-68%) [29,32,34,35]. Little information is available regarding sensitivity for detecting liver metastases originating from pancreatic cancer for the current generation of MDCT scanners (64-detector row or better). Two studies that have compared 64-detector row MDCT with 3T MRI showed for CT a sensitivity of 70% to 76% in the detection of liver metastases compared to 90% to 100% for MRI with either gadobenate dimeglumine or gadoxetic acid [33,36]. Ikuta et al [37] studied 192 patients to compare 4-detector row multiphasic MDCT with CT arterial portography (CTAP) and computed tomography-assisted hepatic arteriography (CTHA) with intraoperative US as the gold standard in the assessment of those patients identified as not having metastatic disease. Of note, CTAP with CTHA is an invasive technique requiring a separate interventional procedure for placement of an arterial catheter to optimize contrast evaluation by CT, and as such is not practiced routinely. Furthermore, MDCT was performed with only four detectors, which is far less than many contemporary scanners. | Staging of Pancreatic Ductal Adenocarcinoma. Studies that have recently examined the role of FDG-PET/CT in the staging of pancreatic cancer have focused on its supplementary ability to detect additional distant metastases beyond those detected by conventional cross-sectional imaging of the abdomen and pelvis or chest, abdomen, and pelvis given the advantage that FDG-PET/CT is a whole-body examination [31]. Nodal staging is a limitation for any of the imaging modalities because of its relative insensitivity to micrometastases detection. Another challenge is the varying imaging criteria for identifying potential nodal involvement between studies. A recent study that used, as criterion for nodal involvement, a nodal short axis diameter of >5 mm or morphologic features of necrosis showed an accuracy of 55% to 60% for the detection of nodal metastatic disease, which is similar to findings seen on older studies regardless of criteria (44%-68%) [29,32,34,35]. Little information is available regarding sensitivity for detecting liver metastases originating from pancreatic cancer for the current generation of MDCT scanners (64-detector row or better). Two studies that have compared 64-detector row MDCT with 3T MRI showed for CT a sensitivity of 70% to 76% in the detection of liver metastases compared to 90% to 100% for MRI with either gadobenate dimeglumine or gadoxetic acid [33,36]. Ikuta et al [37] studied 192 patients to compare 4-detector row multiphasic MDCT with CT arterial portography (CTAP) and computed tomography-assisted hepatic arteriography (CTHA) with intraoperative US as the gold standard in the assessment of those patients identified as not having metastatic disease. Of note, CTAP with CTHA is an invasive technique requiring a separate interventional procedure for placement of an arterial catheter to optimize contrast evaluation by CT, and as such is not practiced routinely. Furthermore, MDCT was performed with only four detectors, which is far less than many contemporary scanners. | 3099847 |
acrac_3099847_7 | Staging of Pancreatic Ductal Adenocarcinoma | In that study, MDCT had a sensitivity of 48.4% and specificity of 98% for liver metastases compared to CTAP + CTHA, which had a sensitivity of 94.2% and specificity of 82.7%. Although the results of CTAP + CTHA were impressive, the data regarding current state-of-the-art MDCT are not representative of modern practice. Peritoneal metastases from pancreatic cancer are typically difficult to identify by any of the modalities because of their typically small size or miliary appearance. In our literature search, no studies that tried to assess overall sensitivity for peritoneal metastases by CT were available, likely because patients were already found to have unresectable disease secondary to other causes such as liver metastases or extensive vascular involvement. Studies that were retrieved in our examination focused on the question of the additional usefulness of preoperative laparoscopic assessment following CT. Results have been controversial, but indirectly these provide information regarding whether CT is sufficient for detection of peritoneal disease for disease management. A meta-analysis of 1,015 patients across 15 studies concluded that, on average, out of 100 patients identified as having resectable disease based on CT, use of follow-up laparoscopy would have avoided 23 unnecessary laparotomies [38]. Another recent meta-analysis that analyzed 12 studies between 1999 and 2010 showed a pooled sensitivity of laparoscopic assessment of 75% for peritoneal implants [39]. In our anecdotal experience, institutions will variably use laparoscopy, sometimes in the setting of suspicion for peritoneal disease, but for some others more globally, with or without laparoscopic peritoneal washing, with the plan to proceed directly to laparotomy at the same setting for planned pancreatic resection in the absence of detection of peritoneal disease. | Staging of Pancreatic Ductal Adenocarcinoma. In that study, MDCT had a sensitivity of 48.4% and specificity of 98% for liver metastases compared to CTAP + CTHA, which had a sensitivity of 94.2% and specificity of 82.7%. Although the results of CTAP + CTHA were impressive, the data regarding current state-of-the-art MDCT are not representative of modern practice. Peritoneal metastases from pancreatic cancer are typically difficult to identify by any of the modalities because of their typically small size or miliary appearance. In our literature search, no studies that tried to assess overall sensitivity for peritoneal metastases by CT were available, likely because patients were already found to have unresectable disease secondary to other causes such as liver metastases or extensive vascular involvement. Studies that were retrieved in our examination focused on the question of the additional usefulness of preoperative laparoscopic assessment following CT. Results have been controversial, but indirectly these provide information regarding whether CT is sufficient for detection of peritoneal disease for disease management. A meta-analysis of 1,015 patients across 15 studies concluded that, on average, out of 100 patients identified as having resectable disease based on CT, use of follow-up laparoscopy would have avoided 23 unnecessary laparotomies [38]. Another recent meta-analysis that analyzed 12 studies between 1999 and 2010 showed a pooled sensitivity of laparoscopic assessment of 75% for peritoneal implants [39]. In our anecdotal experience, institutions will variably use laparoscopy, sometimes in the setting of suspicion for peritoneal disease, but for some others more globally, with or without laparoscopic peritoneal washing, with the plan to proceed directly to laparotomy at the same setting for planned pancreatic resection in the absence of detection of peritoneal disease. | 3099847 |
acrac_3099847_8 | Staging of Pancreatic Ductal Adenocarcinoma | MRI The limitations noted above for studies regarding CT and the accuracy of assessing vascular involvement by tumor apply to MRI as well (with differences in criteria for defining a vessel as involved by tumor, differences in definitions of resectability, and varying generations of equipment, etc. ). Fewer studies are available on the topic of MRI and staging of pancreatic cancer than there are for CT. A study comparing 64-detector row MDCT versus 3T MRI showed for MRI a sensitivity for vascular infiltration of 50% to 80% and a specificity of 96% to 98% [11]. These findings are similar to those found on a meta-analysis of eight studies published between 1997 and 2004 that showed a pooled sensitivity of 67% and pooled specificity of 94% that was not significantly different Staging of Pancreatic Ductal Adenocarcinoma from CT [33]. Therefore, MRI and CT can be considered likely comparable with regard to assessment of vascular involvement by tumor. As noted above, assessment for nodal staging on cross-sectional imaging is limited because of its current inability to identify micrometastases. A critical review article on staging reportedly noted an accuracy ranging from 61% to 77% in radiology studies from 2004 to 2009 for the detection of nodal involvement by tumor [29]. In contrast, MRI has been shown to be likely superior for the detection of liver metastases. Two studies that compared 64-detector row MDCT with 3T MRI showed that CT had a sensitivity of 70% to 76% for the detection of liver metastases compared to 90% to 100% for MRI with either gadobenate dimeglumine or gadoxetic acid [33,36]. The literature search identified only very limited information with regard to MRI and pancreatic cancer peritoneal metastases. A study evaluating the usefulness of staging laparoscopy following staging MRI noted that the yield of staging laparoscopy was marginal and cost effectiveness was reportedly poor for use of this approach [40]. | Staging of Pancreatic Ductal Adenocarcinoma. MRI The limitations noted above for studies regarding CT and the accuracy of assessing vascular involvement by tumor apply to MRI as well (with differences in criteria for defining a vessel as involved by tumor, differences in definitions of resectability, and varying generations of equipment, etc. ). Fewer studies are available on the topic of MRI and staging of pancreatic cancer than there are for CT. A study comparing 64-detector row MDCT versus 3T MRI showed for MRI a sensitivity for vascular infiltration of 50% to 80% and a specificity of 96% to 98% [11]. These findings are similar to those found on a meta-analysis of eight studies published between 1997 and 2004 that showed a pooled sensitivity of 67% and pooled specificity of 94% that was not significantly different Staging of Pancreatic Ductal Adenocarcinoma from CT [33]. Therefore, MRI and CT can be considered likely comparable with regard to assessment of vascular involvement by tumor. As noted above, assessment for nodal staging on cross-sectional imaging is limited because of its current inability to identify micrometastases. A critical review article on staging reportedly noted an accuracy ranging from 61% to 77% in radiology studies from 2004 to 2009 for the detection of nodal involvement by tumor [29]. In contrast, MRI has been shown to be likely superior for the detection of liver metastases. Two studies that compared 64-detector row MDCT with 3T MRI showed that CT had a sensitivity of 70% to 76% for the detection of liver metastases compared to 90% to 100% for MRI with either gadobenate dimeglumine or gadoxetic acid [33,36]. The literature search identified only very limited information with regard to MRI and pancreatic cancer peritoneal metastases. A study evaluating the usefulness of staging laparoscopy following staging MRI noted that the yield of staging laparoscopy was marginal and cost effectiveness was reportedly poor for use of this approach [40]. | 3099847 |
acrac_3099847_9 | Staging of Pancreatic Ductal Adenocarcinoma | EUS EUS A recent meta-analysis of 29 studies that incorporated EUS showed EUS to have a pooled sensitivity of 85% and specificity of 91% for vascular invasion [41]. Notably, the same study noted that the criteria for identifying arterial invasion have not been standardized, which is a constraining factor when attempting to compare between modalities and likely accounts for the wide range of sensitivity for vascular invasion of EUS in this meta-analysis (62% to 100%). The authors noted in their review that there are little comparative data between arterial and venous assessments, and that overall it appeared that CT and EUS performed comparably for assessing venous involvement and that CT may be superior for the assessment of invasion of arterial structures [41]. With regard to nodal disease, EUS has the advantage in that it can be combined with FNA to greatly improve its specificity. A recent meta-analysis of 8 studies showed a pooled sensitivity of 58% and specificity of 85% for detecting nodal metastases with EUS alone [41]. Although the meta-analysis did not include an assessment of multiple studies with EUS that included FNA, the authors did note that EUS would likely improve nodal staging, and cited a study that reported a sensitivity of 82% and specificity of 100% to confirm malignant adenopathy [42]. Because of its narrow field-of-view, and the limited region of anatomic coverage, EUS does not have a role for assessment of peritoneal disease. EUS allows for a limited examination of the left liver lobe and possible FNA of these lesions. No studies have directly compared the accuracy of EUS and cross-sectional imaging for left-sided liver metastasis. Imaging of the right liver is difficult and unreliable by EUS. US Difficulties in visualizing the pancreas in detail because of either body habitus or commonly interposed bowel gas limit the usefulness of transabdominal US for staging. | Staging of Pancreatic Ductal Adenocarcinoma. EUS EUS A recent meta-analysis of 29 studies that incorporated EUS showed EUS to have a pooled sensitivity of 85% and specificity of 91% for vascular invasion [41]. Notably, the same study noted that the criteria for identifying arterial invasion have not been standardized, which is a constraining factor when attempting to compare between modalities and likely accounts for the wide range of sensitivity for vascular invasion of EUS in this meta-analysis (62% to 100%). The authors noted in their review that there are little comparative data between arterial and venous assessments, and that overall it appeared that CT and EUS performed comparably for assessing venous involvement and that CT may be superior for the assessment of invasion of arterial structures [41]. With regard to nodal disease, EUS has the advantage in that it can be combined with FNA to greatly improve its specificity. A recent meta-analysis of 8 studies showed a pooled sensitivity of 58% and specificity of 85% for detecting nodal metastases with EUS alone [41]. Although the meta-analysis did not include an assessment of multiple studies with EUS that included FNA, the authors did note that EUS would likely improve nodal staging, and cited a study that reported a sensitivity of 82% and specificity of 100% to confirm malignant adenopathy [42]. Because of its narrow field-of-view, and the limited region of anatomic coverage, EUS does not have a role for assessment of peritoneal disease. EUS allows for a limited examination of the left liver lobe and possible FNA of these lesions. No studies have directly compared the accuracy of EUS and cross-sectional imaging for left-sided liver metastasis. Imaging of the right liver is difficult and unreliable by EUS. US Difficulties in visualizing the pancreas in detail because of either body habitus or commonly interposed bowel gas limit the usefulness of transabdominal US for staging. | 3099847 |
acrac_3099847_10 | Staging of Pancreatic Ductal Adenocarcinoma | FDG-PET/CT As noted earlier, there is considerable variability in how the CT portion of the examination is obtained for FDG- PET/CT with regard to whether IV or oral contrast is administered. When performed without IV contrast, it does not have a role in the assessment for potential vascular involvement. When performed with IV contrast enhancement, it is typically acquired as a single phase of contrast enhancement at variable slice thickness and variable reconstructed display field-of-view between institutions. These parameters would affect the usefulness and effectiveness of local staging. FDG-PET/CT, when used in the setting of preoperative staging, is therefore typically used as a whole-body examination for follow-up to contrast-enhanced CT or MRI, which themselves would already provide information regarding liver metastases, potential peritoneal implants, and possible adenopathy. This is likely why most of the studies retrieved in our literature search evaluated the usefulness of FDG-PET/CT as a follow-up study whole body examination to conventional cross-sectional imaging for the detection of unexpected distant metastases. One of the challenges encountered in evaluating the studies, is that often distant metastases (liver, peritoneal, lung, bone, nodes) were put together into a single group rather than subgroups by the type of distant metastasis. The results are variable across studies with the detection rate of unexpected distant metastases generally identified in patients as probably resectable based on contrast-enhanced CT or MRI, ranging from 2.5% to 41% [43-48]. A recent meta-analysis of FDG-PET/CT imaging (4 studies, 101 patients) showed a pooled sensitivity of 64% and specificity of 81% for metastatic nodal disease, and a sensitivity of 67% and specificity of 96% for liver metastases [49]. Staging of Pancreatic Ductal Adenocarcinoma Variant 2: Pancreatic ductal adenocarcinoma. Follow-up post-neoadjuvant therapy. | Staging of Pancreatic Ductal Adenocarcinoma. FDG-PET/CT As noted earlier, there is considerable variability in how the CT portion of the examination is obtained for FDG- PET/CT with regard to whether IV or oral contrast is administered. When performed without IV contrast, it does not have a role in the assessment for potential vascular involvement. When performed with IV contrast enhancement, it is typically acquired as a single phase of contrast enhancement at variable slice thickness and variable reconstructed display field-of-view between institutions. These parameters would affect the usefulness and effectiveness of local staging. FDG-PET/CT, when used in the setting of preoperative staging, is therefore typically used as a whole-body examination for follow-up to contrast-enhanced CT or MRI, which themselves would already provide information regarding liver metastases, potential peritoneal implants, and possible adenopathy. This is likely why most of the studies retrieved in our literature search evaluated the usefulness of FDG-PET/CT as a follow-up study whole body examination to conventional cross-sectional imaging for the detection of unexpected distant metastases. One of the challenges encountered in evaluating the studies, is that often distant metastases (liver, peritoneal, lung, bone, nodes) were put together into a single group rather than subgroups by the type of distant metastasis. The results are variable across studies with the detection rate of unexpected distant metastases generally identified in patients as probably resectable based on contrast-enhanced CT or MRI, ranging from 2.5% to 41% [43-48]. A recent meta-analysis of FDG-PET/CT imaging (4 studies, 101 patients) showed a pooled sensitivity of 64% and specificity of 81% for metastatic nodal disease, and a sensitivity of 67% and specificity of 96% for liver metastases [49]. Staging of Pancreatic Ductal Adenocarcinoma Variant 2: Pancreatic ductal adenocarcinoma. Follow-up post-neoadjuvant therapy. | 3099847 |
acrac_3099847_11 | Staging of Pancreatic Ductal Adenocarcinoma | Evaluate resectability for borderline resectable tumor. Only five articles that addressed the topic of preoperative therapy in the context of staging a tumor were identified in the literature search. CT CT Only very limited information is available regarding staging in the setting of preoperative chemotherapy and/or radiation therapy. Challenges include differences in treatment regimens. A small study comparing 31 patients who had undergone neoadjuvant therapy (between 2005 and 2010) for locally advanced disease that went on to attempted curative resection with a control group of 41 patients who went directly to surgery showed that the accuracy of MDCT (in this study, 16- and 64-detector row) for determining resectability was significantly less in the neoadjuvant group (58% versus 83%), primarily secondary to an overestimation of vascular invasion [50]. This study was limited by a mix of treatment regimens including chemotherapy alone, radiation therapy alone, and combination chemoradiation. Other studies have also shown that imaging signs of vascular involvement by tumor persist even after successful therapy because of the inability of imaging to distinguish viable from nonviable tumor [51,52]. No information was available from our search in regard to the accuracy of identifying nodal metastases, liver metastases, or peritoneal disease in the setting of neoadjuvant therapy. MRI The literature search did not identify any studies that examined the accuracy of MRI in the assessment of staging following preoperative therapy. EUS The literature search did not identify any studies that examined the accuracy of EUS in the assessment of vascular involvement by tumor following neoadjuvant therapy. US The literature search did not identify any studies that examined the accuracy of transabdominal US in the assessment of vascular involvement by tumor following neoadjuvant therapy. | Staging of Pancreatic Ductal Adenocarcinoma. Evaluate resectability for borderline resectable tumor. Only five articles that addressed the topic of preoperative therapy in the context of staging a tumor were identified in the literature search. CT CT Only very limited information is available regarding staging in the setting of preoperative chemotherapy and/or radiation therapy. Challenges include differences in treatment regimens. A small study comparing 31 patients who had undergone neoadjuvant therapy (between 2005 and 2010) for locally advanced disease that went on to attempted curative resection with a control group of 41 patients who went directly to surgery showed that the accuracy of MDCT (in this study, 16- and 64-detector row) for determining resectability was significantly less in the neoadjuvant group (58% versus 83%), primarily secondary to an overestimation of vascular invasion [50]. This study was limited by a mix of treatment regimens including chemotherapy alone, radiation therapy alone, and combination chemoradiation. Other studies have also shown that imaging signs of vascular involvement by tumor persist even after successful therapy because of the inability of imaging to distinguish viable from nonviable tumor [51,52]. No information was available from our search in regard to the accuracy of identifying nodal metastases, liver metastases, or peritoneal disease in the setting of neoadjuvant therapy. MRI The literature search did not identify any studies that examined the accuracy of MRI in the assessment of staging following preoperative therapy. EUS The literature search did not identify any studies that examined the accuracy of EUS in the assessment of vascular involvement by tumor following neoadjuvant therapy. US The literature search did not identify any studies that examined the accuracy of transabdominal US in the assessment of vascular involvement by tumor following neoadjuvant therapy. | 3099847 |
acrac_3099847_12 | Staging of Pancreatic Ductal Adenocarcinoma | FDG-PET/CT The literature search did not identify any studies that examined the accuracy of FDG-PET/CT in the assessment of staging following neoadjuvant therapy. Reporting of Imaging Findings for Staging Pancreatic Cancer An emerging issue has been the reporting of findings for staging for pancreatic cancer by radiologists, namely, the usefulness of structured reporting or template reporting versus free-form (nonstructured) dictation. A single institution study had surgeons evaluate 48 structured and 72 nonstructured reports and found that information for surgical planning was readily accessible in 60% to 98% of structured reports, but only 32% to 54% in nonstructured reports [53]. In a retrospective study of 200 reports reviewed by radiologists, it was noted that in 20.3% of reports, resectability status could not be determined based on the report alone [54]. Although there are references that report on studies with design limitations, 16 well-designed or good-quality studies provide good evidence. Appropriateness Category Names and Definitions Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, both because of organ sensitivity and longer life expectancy (relevant to the long latency that appears to accompany radiation exposure). For these reasons, the RRL dose estimate ranges for pediatric examinations are lower as compared to those specified for adults (see Table below). Additional | Staging of Pancreatic Ductal Adenocarcinoma. FDG-PET/CT The literature search did not identify any studies that examined the accuracy of FDG-PET/CT in the assessment of staging following neoadjuvant therapy. Reporting of Imaging Findings for Staging Pancreatic Cancer An emerging issue has been the reporting of findings for staging for pancreatic cancer by radiologists, namely, the usefulness of structured reporting or template reporting versus free-form (nonstructured) dictation. A single institution study had surgeons evaluate 48 structured and 72 nonstructured reports and found that information for surgical planning was readily accessible in 60% to 98% of structured reports, but only 32% to 54% in nonstructured reports [53]. In a retrospective study of 200 reports reviewed by radiologists, it was noted that in 20.3% of reports, resectability status could not be determined based on the report alone [54]. Although there are references that report on studies with design limitations, 16 well-designed or good-quality studies provide good evidence. Appropriateness Category Names and Definitions Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, both because of organ sensitivity and longer life expectancy (relevant to the long latency that appears to accompany radiation exposure). For these reasons, the RRL dose estimate ranges for pediatric examinations are lower as compared to those specified for adults (see Table below). Additional | 3099847 |
acrac_3099011_0 | Back Pain Child PCAs | Introduction/Background It is now generally accepted that nontraumatic back pain in the pediatric population is common. Evaluation of the spine in the setting of trauma will be addressed with a forthcoming ACR Appropriateness Criteria guideline. Early studies have reported prevalence as low as 2%, with more recent evidence suggesting that up to half of the pediatric population experiences back pain [1]. The incidence of back pain increases throughout childhood, most notably lower back pain [2]. Childhood back pain may be predictive of adult back pain [2]. Female sex, poor general health, high level of activity, backpack loads, and family history of back pain are risk factors that have been suggested [3]. Most pediatric back pain is mechanical and responds to conservative treatment with imaging not required in the clinical evaluation [1,4-6]. However, back pain may be caused by more serious conditions, including the broad categories of traumatic, infectious, inflammatory, congenital, and neoplastic processes [7,8]. Evaluation of scoliosis associated with pain will be addressed under a separate ACR Appropriateness Criteria guideline. Back pain is common in the pediatric athlete, with many potential etiologies [9]. The presence of isolated back pain in a child has previously been an indication for imaging; however, recently a more conservative approach has been suggested. As in adults, a diagnostic algorithm is suggested for evaluation of children with back pain in order to reduce the number of unnecessary examinations performed and resultant radiation exposure [10]. Children with back pain of short duration, a normal physical examination, and minor or no history of trauma will likely benefit little from further laboratory or imaging evaluation [1,8,11]. Imaging should be reserved for the presence of persistent back pain with concerning clinical and laboratory findings. | Back Pain Child PCAs. Introduction/Background It is now generally accepted that nontraumatic back pain in the pediatric population is common. Evaluation of the spine in the setting of trauma will be addressed with a forthcoming ACR Appropriateness Criteria guideline. Early studies have reported prevalence as low as 2%, with more recent evidence suggesting that up to half of the pediatric population experiences back pain [1]. The incidence of back pain increases throughout childhood, most notably lower back pain [2]. Childhood back pain may be predictive of adult back pain [2]. Female sex, poor general health, high level of activity, backpack loads, and family history of back pain are risk factors that have been suggested [3]. Most pediatric back pain is mechanical and responds to conservative treatment with imaging not required in the clinical evaluation [1,4-6]. However, back pain may be caused by more serious conditions, including the broad categories of traumatic, infectious, inflammatory, congenital, and neoplastic processes [7,8]. Evaluation of scoliosis associated with pain will be addressed under a separate ACR Appropriateness Criteria guideline. Back pain is common in the pediatric athlete, with many potential etiologies [9]. The presence of isolated back pain in a child has previously been an indication for imaging; however, recently a more conservative approach has been suggested. As in adults, a diagnostic algorithm is suggested for evaluation of children with back pain in order to reduce the number of unnecessary examinations performed and resultant radiation exposure [10]. Children with back pain of short duration, a normal physical examination, and minor or no history of trauma will likely benefit little from further laboratory or imaging evaluation [1,8,11]. Imaging should be reserved for the presence of persistent back pain with concerning clinical and laboratory findings. | 3099011 |
acrac_3099011_1 | Back Pain Child PCAs | Laboratory evaluation with a complete blood count and sedimentation rate may be of use to evaluate for a systemic etiology [12-14]. Clinical and laboratory findings suggesting an infectious or neoplastic etiology should be imaged without delay. The presence of constant pain, night pain, and radicular pain, alone or in combination, lasting for 4 weeks or more, constitute clinical red flags that should prompt further imaging. An abnormal neurologic examination should prompt immediate imaging [1,4,5]. Overview of Imaging Modalities Radiographs Radiographs of the symptomatic region are a useful initial imaging modality, as they are readily available and may lead to a diagnosis in a significant number of patients [4]. Vertebral alignment, spinal curvature, and disc height can easily be ascertained using radiographs. The presence of spondylolysis, Scheuermann disease, and primary bone tumors may be suggested on radiographs and direct any further imaging [4,15,16]. Oblique views of the lumbar spine have been shown to double the radiation dose delivered without any additional helpful information beyond the standard frontal and lateral views [6,9]. Radiographs are insensitive to paraspinal and intraspinal soft-tissue masses. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] Magnetic Resonance Imaging MRI without contrast has been shown to be an effective screening tool in evaluating pediatric patients with certain red-flag clinical presentations [1,5]. In young patients, the MRI examination may need to be performed under sedation. MRI is the only modality that directly visualizes the spinal cord, ligaments, and intervertebral discs. | Back Pain Child PCAs. Laboratory evaluation with a complete blood count and sedimentation rate may be of use to evaluate for a systemic etiology [12-14]. Clinical and laboratory findings suggesting an infectious or neoplastic etiology should be imaged without delay. The presence of constant pain, night pain, and radicular pain, alone or in combination, lasting for 4 weeks or more, constitute clinical red flags that should prompt further imaging. An abnormal neurologic examination should prompt immediate imaging [1,4,5]. Overview of Imaging Modalities Radiographs Radiographs of the symptomatic region are a useful initial imaging modality, as they are readily available and may lead to a diagnosis in a significant number of patients [4]. Vertebral alignment, spinal curvature, and disc height can easily be ascertained using radiographs. The presence of spondylolysis, Scheuermann disease, and primary bone tumors may be suggested on radiographs and direct any further imaging [4,15,16]. Oblique views of the lumbar spine have been shown to double the radiation dose delivered without any additional helpful information beyond the standard frontal and lateral views [6,9]. Radiographs are insensitive to paraspinal and intraspinal soft-tissue masses. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: [email protected] Magnetic Resonance Imaging MRI without contrast has been shown to be an effective screening tool in evaluating pediatric patients with certain red-flag clinical presentations [1,5]. In young patients, the MRI examination may need to be performed under sedation. MRI is the only modality that directly visualizes the spinal cord, ligaments, and intervertebral discs. | 3099011 |
acrac_3099011_2 | Back Pain Child PCAs | T2- weighted images and fat-suppression techniques are necessary for evaluating for marrow edema and paraspinal pathology. MRI without contrast is often able to determine a cause of mechanical back pain, most commonly spondylolysis, with high sensitivity [22-24]. Recent studies have demonstrated MRI to be more sensitive than computed tomography (CT) and a potential first-line test in the evaluation of spondylolysis [23,24]. Fluid- sensitive and fat-suppressed MRI techniques are able to identify stress reaction (marrow edema) in the pedicles as well as spondylolisthesis, which are the 2 findings that guide management of these patients [22,24]. MRI is optimal for demonstrating degenerative disc pathology, which may be more common in the pediatric population than previously suspected [25,26]. The main advantage of MRI is optimal intraspinal and paraspinal soft-tissue evaluation. Intraspinal tumors can present with back pain and MRI is the indicated imaging modality in this subset of patients [27,28]. Osteomyelitis and epidural and paraspinal infection are well demonstrated on MRI and can guide surgical intervention [13,14,29]. Fat-suppressed T2 and T1 postcontrast MRI sequences such as short tau inversion recovery, Dixon, and fat-suppressed turbo spin echo are necessary for evaluation of suspected infectious or neoplastic disease involving the vertebrae, discs, or paraspinous soft tissues [8]. Computed Tomography CT without contrast provides excellent bone detail. The modality is suboptimal for evaluating the intraspinal contents and the paraspinal soft tissues in comparison with MRI. The ability of CT to reconstruct in multiple planes and perform 3D volume-rendered images is an advantage. CT targeted to the area of interest can be useful in the evaluation of suspected spondylolysis as well as primary bone tumors such as osteoid osteoma, osteoblastoma, and aneurysmal bone cyst [15,27,30]. However, CT does not demonstrate associated marrow edema. | Back Pain Child PCAs. T2- weighted images and fat-suppression techniques are necessary for evaluating for marrow edema and paraspinal pathology. MRI without contrast is often able to determine a cause of mechanical back pain, most commonly spondylolysis, with high sensitivity [22-24]. Recent studies have demonstrated MRI to be more sensitive than computed tomography (CT) and a potential first-line test in the evaluation of spondylolysis [23,24]. Fluid- sensitive and fat-suppressed MRI techniques are able to identify stress reaction (marrow edema) in the pedicles as well as spondylolisthesis, which are the 2 findings that guide management of these patients [22,24]. MRI is optimal for demonstrating degenerative disc pathology, which may be more common in the pediatric population than previously suspected [25,26]. The main advantage of MRI is optimal intraspinal and paraspinal soft-tissue evaluation. Intraspinal tumors can present with back pain and MRI is the indicated imaging modality in this subset of patients [27,28]. Osteomyelitis and epidural and paraspinal infection are well demonstrated on MRI and can guide surgical intervention [13,14,29]. Fat-suppressed T2 and T1 postcontrast MRI sequences such as short tau inversion recovery, Dixon, and fat-suppressed turbo spin echo are necessary for evaluation of suspected infectious or neoplastic disease involving the vertebrae, discs, or paraspinous soft tissues [8]. Computed Tomography CT without contrast provides excellent bone detail. The modality is suboptimal for evaluating the intraspinal contents and the paraspinal soft tissues in comparison with MRI. The ability of CT to reconstruct in multiple planes and perform 3D volume-rendered images is an advantage. CT targeted to the area of interest can be useful in the evaluation of suspected spondylolysis as well as primary bone tumors such as osteoid osteoma, osteoblastoma, and aneurysmal bone cyst [15,27,30]. However, CT does not demonstrate associated marrow edema. | 3099011 |
acrac_3099011_3 | Back Pain Child PCAs | Also, intrinsic fluid-fluid levels and associated soft-tissue abnormalities are better demonstrated on MRI. Apophyseal ring fractures are also well evaluated on CT [31]. CT with contrast can be considered when infection and abscess are suspected and MRI is contraindicated or not feasible. Myelography and Postmyelography Computed Tomography Spine The indication for myelography and postmyelography CT is narrow and limited because of its invasiveness and limited diagnostic yield. Myelography and postmyelography CT can be considered in conditions where intraspinal pathology is suspected and MRI is either contraindicated or will be significantly limited by existing hardware. Discussion of Imaging Modalities by Variant Variant 1: Child. Back pain with none of the following clinical red flags: constant pain, night pain, radicular pain, pain lasting >4 weeks, abnormal neurologic examination. Initial imaging evaluation. Radiographs There is little evidence that radiographic evaluation of the region of interest in acute uncomplicated back pain without an associated traumatic event is indicated [8,9,11,12]. MRI Spine MRI is not indicated in back pain without clinical red flags present [1,4,5]. If an inflammatory, infectious, or neoplastic process is suggested from initial clinical or laboratory evaluation, MRI without and with contrast of the complete spine is the suggested imaging modality in further imaging evaluation [8,27,28]. If contrast is administered, precontrast images are helpful to assess enhancement. There is little use for performing an MRI with contrast only. CT Spine CT is not indicated for evaluation of patients with back pain and no clinical red flags. If an inflammatory, infectious, or neoplastic process is suggested from initial clinical or laboratory evaluation and MRI cannot be obtained, a CT spine with contrast targeted to the area of interest may be indicated. CT spine without and with contrast is not indicated for evaluation of patients with back pain and no red flags. | Back Pain Child PCAs. Also, intrinsic fluid-fluid levels and associated soft-tissue abnormalities are better demonstrated on MRI. Apophyseal ring fractures are also well evaluated on CT [31]. CT with contrast can be considered when infection and abscess are suspected and MRI is contraindicated or not feasible. Myelography and Postmyelography Computed Tomography Spine The indication for myelography and postmyelography CT is narrow and limited because of its invasiveness and limited diagnostic yield. Myelography and postmyelography CT can be considered in conditions where intraspinal pathology is suspected and MRI is either contraindicated or will be significantly limited by existing hardware. Discussion of Imaging Modalities by Variant Variant 1: Child. Back pain with none of the following clinical red flags: constant pain, night pain, radicular pain, pain lasting >4 weeks, abnormal neurologic examination. Initial imaging evaluation. Radiographs There is little evidence that radiographic evaluation of the region of interest in acute uncomplicated back pain without an associated traumatic event is indicated [8,9,11,12]. MRI Spine MRI is not indicated in back pain without clinical red flags present [1,4,5]. If an inflammatory, infectious, or neoplastic process is suggested from initial clinical or laboratory evaluation, MRI without and with contrast of the complete spine is the suggested imaging modality in further imaging evaluation [8,27,28]. If contrast is administered, precontrast images are helpful to assess enhancement. There is little use for performing an MRI with contrast only. CT Spine CT is not indicated for evaluation of patients with back pain and no clinical red flags. If an inflammatory, infectious, or neoplastic process is suggested from initial clinical or laboratory evaluation and MRI cannot be obtained, a CT spine with contrast targeted to the area of interest may be indicated. CT spine without and with contrast is not indicated for evaluation of patients with back pain and no red flags. | 3099011 |
acrac_3099011_4 | Back Pain Child PCAs | Bone Scan Whole Body with SPECT or SPECT/CT Complete Spine SPECT bone scan is not indicated for evaluation of patients with back pain and no red flags. Myelography and Postmyelography CT Spine This examination is not indicated for evaluation of patients with back pain and no red flags. Variant 2: Child. Back pain with 1 or more of the following clinical red flags: constant pain, night pain, radicular pain, pain lasting >4 weeks, abnormal neurologic examination. Initial imaging evaluation. Radiographs Radiographs of the cervical, thoracic, or lumbar spine are a useful initial diagnostic imaging procedure for evaluation of back pain in children. Radiographs can demonstrate findings that lead to the diagnosis in up to 24% of children [1,4,5]. Anterior-posterior radiographs are typically sufficient, with additional views only adding to the radiation dose without increase in diagnostic yield. Collimation to the area of concern may aid in the diagnosis [6,9]. Pathologic conditions that can be diagnosed on radiographs include spondylolysis, scoliosis, Scheuermann disease, and bone tumors [1,4,5]. In children with back pain and clinical red flags, negative radiographs are not considered adequate to exclude pathology and additional advanced imaging techniques are required [1,5]. Positive radiographs leading to a specific diagnosis may guide therapy without additional imaging or direct further appropriate imaging evaluation [1,4,5]. MRI Spine Noncontrast MRI of the spine targeted to the region of interest is sensitive for the imaging evaluation of soft- tissue and bony abnormalities associated with pediatric back pain, including paraspinous soft-tissue pathology, disc disease, marrow edema, and intraspinal masses [8,24-26,32]. However, radiographs should be the initial imaging evaluation in most cases. MRI of the total spine may be indicated as the initial evaluation of patients with abnormal neurologic findings. | Back Pain Child PCAs. Bone Scan Whole Body with SPECT or SPECT/CT Complete Spine SPECT bone scan is not indicated for evaluation of patients with back pain and no red flags. Myelography and Postmyelography CT Spine This examination is not indicated for evaluation of patients with back pain and no red flags. Variant 2: Child. Back pain with 1 or more of the following clinical red flags: constant pain, night pain, radicular pain, pain lasting >4 weeks, abnormal neurologic examination. Initial imaging evaluation. Radiographs Radiographs of the cervical, thoracic, or lumbar spine are a useful initial diagnostic imaging procedure for evaluation of back pain in children. Radiographs can demonstrate findings that lead to the diagnosis in up to 24% of children [1,4,5]. Anterior-posterior radiographs are typically sufficient, with additional views only adding to the radiation dose without increase in diagnostic yield. Collimation to the area of concern may aid in the diagnosis [6,9]. Pathologic conditions that can be diagnosed on radiographs include spondylolysis, scoliosis, Scheuermann disease, and bone tumors [1,4,5]. In children with back pain and clinical red flags, negative radiographs are not considered adequate to exclude pathology and additional advanced imaging techniques are required [1,5]. Positive radiographs leading to a specific diagnosis may guide therapy without additional imaging or direct further appropriate imaging evaluation [1,4,5]. MRI Spine Noncontrast MRI of the spine targeted to the region of interest is sensitive for the imaging evaluation of soft- tissue and bony abnormalities associated with pediatric back pain, including paraspinous soft-tissue pathology, disc disease, marrow edema, and intraspinal masses [8,24-26,32]. However, radiographs should be the initial imaging evaluation in most cases. MRI of the total spine may be indicated as the initial evaluation of patients with abnormal neurologic findings. | 3099011 |
acrac_3099011_5 | Back Pain Child PCAs | Contrast is helpful in the evaluation of back pain in children when there is clinical or laboratory evidence of infection, inflammation, or tumor [8,13,33]. If contrast is administered, precontrast images are helpful to assess enhancement. There is little use for performing an MRI with contrast only. CT Spine Bone lesions and fractures are well delineated on targeted noncontrast CT [7,15]. However, radiographs should be obtained initially. Although CT with contrast may be helpful when infection or tumor is suspected, MRI without and with contrast is the modality of choice in the evaluation of these patients. CT with contrast should be considered only when MRI is contraindicated or not feasible. CT both without and with contrast is not usually indicated. In the circumstance where there is a need to determine the presence of calcifications, limited noncontrast images could be obtained through the area of interest. Bone Scan Whole Body with SPECT or SPECT/CT Complete Spine Tc-99m bone scan may be a useful screening tool in children with back pain and no specific neurologic findings on physical examination [4]. However, radiographs should be the initial imaging examination and may direct further evaluation. Myelography and Postmyelography CT Spine Because of the invasiveness of the procedure, myelography and postmyelography CT of the whole spine are considered in the setting of an abnormal neurologic examination only if MRI is contraindicated or will have significantly limited diagnostic yield because of spinal hardware. Variant 3: Child. Back pain with 1 or more of the following clinical red flags: constant pain, night pain, radicular pain, pain lasting >4 weeks, abnormal neurologic examination. Negative radiographs. Children with negative radiographs and back pain associated with clinical red flags should undergo additional imaging evaluation. | Back Pain Child PCAs. Contrast is helpful in the evaluation of back pain in children when there is clinical or laboratory evidence of infection, inflammation, or tumor [8,13,33]. If contrast is administered, precontrast images are helpful to assess enhancement. There is little use for performing an MRI with contrast only. CT Spine Bone lesions and fractures are well delineated on targeted noncontrast CT [7,15]. However, radiographs should be obtained initially. Although CT with contrast may be helpful when infection or tumor is suspected, MRI without and with contrast is the modality of choice in the evaluation of these patients. CT with contrast should be considered only when MRI is contraindicated or not feasible. CT both without and with contrast is not usually indicated. In the circumstance where there is a need to determine the presence of calcifications, limited noncontrast images could be obtained through the area of interest. Bone Scan Whole Body with SPECT or SPECT/CT Complete Spine Tc-99m bone scan may be a useful screening tool in children with back pain and no specific neurologic findings on physical examination [4]. However, radiographs should be the initial imaging examination and may direct further evaluation. Myelography and Postmyelography CT Spine Because of the invasiveness of the procedure, myelography and postmyelography CT of the whole spine are considered in the setting of an abnormal neurologic examination only if MRI is contraindicated or will have significantly limited diagnostic yield because of spinal hardware. Variant 3: Child. Back pain with 1 or more of the following clinical red flags: constant pain, night pain, radicular pain, pain lasting >4 weeks, abnormal neurologic examination. Negative radiographs. Children with negative radiographs and back pain associated with clinical red flags should undergo additional imaging evaluation. | 3099011 |
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