Malignant or Aggressive Primary Musculoskeletal Tumor Staging And Surveillance PCAs. MRI Area of Interest Without IV Contrast MRI used as surveillance of the primary soft tissue tumor site is the mainstay for evaluating local recurrence. Few studies regarding the diagnostic utility of MRI for local recurrence of soft tissue sarcomas have been published in recent years, likely given its widespread adoption clinically. MRI is useful not only for asymptomatic surveillance but also if a clinical area of concern at the resection site develops. MRI is often requested before surgery and radiation when local recurrence is established. A retrospective single-institution study by Park et al [77] of 325 patients with extremity sarcoma with a local recurrence rate of 11% found MRI detected 60% of those patients with recurrence not identified clinically or with US. Those with MRI detected local recurrence trended towards better survival but this did not reach statistical significance.


Malignant or Aggressive Primary Musculoskeletal Tumor Staging And Surveillance PCAs. MRI has been criticized as having many false-positive results leading to unnecessary procedures and emotional distress [82]. A retrospective single-institution study of 11 local recurrences in 124 patients with soft tissue sarcoma found MRI had a positive predictive value of only 42% with 11 false-positive examinations in this cohort and advocated for clinical surveillance only [83]. However, the Park et al [77] larger single-institution studies found a positive predictive value of 93%.


Malignant or Aggressive Primary Musculoskeletal Tumor Staging And Surveillance PCAs. 12 Malignant or Aggressive Primary Musculoskeletal Tumor


Malignant or Aggressive Primary Musculoskeletal Tumor Staging And Surveillance PCAs. Postcontrast imaging has been shown to add benefit in evaluation of soft tissue tumors to differentiate benign versus malignant lesions [68]. A more recent retrospective study assessing the added value of postcontrast MRI showed contrast improved reader confidence even for experienced readers and improved accuracy of a more inexperienced reader from 65% to 72% [67]. However, MRI without IV contrast is still highly sensitive in detecting local recurrence of soft tissue tumor because of an inherent soft tissue contrast of MRI and therefore is still of benefit.


Malignant or Aggressive Primary Musculoskeletal Tumor Staging And Surveillance PCAs. Radiography Area of Interest In rare instances of a primary soft tissue tumor that produces osseous or chondroid matrix, there may be limited benefit of radiography area of interest for detecting local recurrence, but in general this modality is usually not helpful for most patients. There is no relevant literature to support the use of radiography alone as surveillance for local recurrence of malignant or aggressive primary soft tissue tumors.


Malignant or Aggressive Primary Musculoskeletal Tumor Staging And Surveillance PCAs. US Area of Interest Local recurrence of a soft tissue tumor can be detected with US. Note that most studies comparing US with MRI are outdated because both US and MRI technology have advanced significantly. A more recent retrospective single- center study of 68 patients with extremity soft tissue sarcomas (28% recurrence rate) followed with US and MRI found a sensitivity of 88% and specificity of 94% in the detection of local recurrences with US, with a negative predictive value of 96%; both US false-negative lesions were identified with MRI in this study [84].


Malignant or Aggressive Primary Musculoskeletal Tumor Staging And Surveillance PCAs. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.


Malignant or Aggressive Primary Musculoskeletal Tumor Staging And Surveillance PCAs. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Scoliosis Child

Scoliosis Child. It should be noted that the diagnosis of idiopathic scoliosis is of exclusion. This includes exclusion of a variety of neuromuscular disorders commonly associated with scoliosis, such as cerebral palsy and muscular dystrophy. Intramedullary, extramedullary, and vertebral tumors can be associated with scoliosis, with osteoid osteoma of the posterior elements perhaps being the most well-known. Vertebral infections, such as tuberculosis, may also result in kyphoscoliosis [1,2]. Conditions with dysplastic skeletal development should also be clinically excluded, including osteogenesis imperfecta, neurofibromatosis type I, Marfan syndrome, Ehlers-Danlos syndrome, and achondroplasia. Clinical presentation and physical examination in idiopathic scoliosis are negative for cutaneous stigmata that suggest underlying spinal dysraphism (hemangioma, hairy patches, nevi, dermal appendages, or sinus tracts) [10].


Scoliosis Child

Scoliosis Child. When radiographs reveal anomalies of vertebral formation or segmentation, the scoliosis is termed congenital, accounting for up to 10% of surgical patients [2]. Neural axis anomalies, such as hydrosyringomyelia, Chiari malformation, and cord tethering, have been reported to occur in more than 20% of such patients who thus may benefit from routine preoperative MRI [11].


Scoliosis Child

Scoliosis Child. 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.


Scoliosis Child

Scoliosis Child. Reprint requests to: publications@acr.org


Scoliosis Child

Scoliosis Child. MRI MRI of the spine, with its superior soft-tissue contrast is selectively used in the setting of scoliosis to detect and characterize suspected intraspinal abnormalities. Intravenous (IV) gadolinium-based contrast agents are not routinely used in the setting of scoliosis, except in those instances when tumor or infection is a consideration.


Scoliosis Child

Scoliosis Child. CT Multiplanar and 3-D reconstruction CT of the bony spine can help in selected cases for presurgical planning. In addition, the volumetric CT data can be used for surgical navigation [16,17]. CT may also be used to characterize and define the extent of the lesion, such as with the nidus of an osteoid osteoma. CT can be rapidly acquired, and low-dose protocols have been developed and implemented [18]. IV iodine-based contrast is almost never warranted in the perioperative setting, the exception being when tumor or infection is suspected and MRI with contrast cannot be obtained because of a contraindication.


Scoliosis Child

Scoliosis Child. Bone Scan Tc-99m methyl diphosphonate (MDP) bone scintigraphy has been advocated in the specific setting of painful scoliosis and is particularly sensitive in cases with primary bone tumors, such as osteoid osteoma or osteoblastoma, spondylolysis, and infection. However, generalized pain is common in scoliosis, occurring in up to a third of idiopathic cases, and radiography often demonstrates the etiology in those individuals with an underlying bone abnormality [19]. Bone scintigraphy findings are usually not specific. Therefore, after initial evaluation with radiography, MRI is generally the second-line imaging modality even in the setting where a primary bone tumor, such as osteoid osteoma, is a consideration [20].


Scoliosis Child

Scoliosis Child. Discussion of Procedures by Variant Variant 1: Child. Congenital scoliosis. Initial imaging. The body regions covered in this clinical scenario are the cervical, thoracic, and lumbar spine. These body regions might be evaluated separately or in combination as guided by physical examination findings, patient history, and other available information, including prior imaging.


Scoliosis Child

Scoliosis Child. MRI Complete Spine Congenital scoliosis as a result of abnormal vertebral formation and segmentation has been shown to be associated with a high incidence of intraspinal anomalies, with a reported prevalence ranging from 20% to 58% [11]. Underlying anomalies include tethered cord, filar lipoma, syringohydromyelia, and diastematomyelia [11]. In a study of 76 patients, Belmont et al [11] noted a prevalence of intraspinal anomalies in 28% of patients with isolated hemivertebra and 21% of patients with more complex vertebral anomalies. Interestingly, history and


Scoliosis Child

Scoliosis Child. physical examination only demonstrated an accuracy of 62% for diagnosing an intraspinal anomaly with a hemivertebra. Shen et al [24], in a study of 226 Chinese surgical cases for congenital scoliosis, found a 43% incidence of intraspinal anomalies, the most common being diastematomyelia. Again, similar to the study by Belmont et al, a negative neurologic examination did not predict a normal MRI examination. MRI was suggested in both of these studies for the complete evaluation of congenital scoliosis.


Scoliosis Child

Scoliosis Child. CT Spine CT may play a role in the initial imaging evaluation of congenital scoliosis. Multiplanar and 3-D volume rendered reformatted images derived from the axially acquired data set provide multiple views of the spine, allowing a perspective not readily available with conventional radiographs [25,26]. CT may specifically aid in the visualization and characterization of the osseous septum in type I split cord malformations [27]. CT is also helpful in presurgical planning for congenital scoliosis, facilitating visualization of the bony malformations and reducing instrumentation-related complications. Wu et al [26] reported a reduction in the rate of screw misplacement using CT-assisted planning, 6.5% as compared to 15.3% when using C-arm alone.


Scoliosis Child

Scoliosis Child. Bone Scan Complete Spine Tc-99m MDP is not a primary imaging modality in the setting of congenital scoliosis as it provides no intraspinal information.


Scoliosis Child

Scoliosis Child. Variant 2: Child (0 to 9 years of age). Early onset idiopathic scoliosis. Initial imaging. The body regions covered in this clinical scenario are the cervical, thoracic, and lumbar spine. These body regions might be evaluated separately or in combination as guided by physical examination findings, patient history, and other available information, including prior imaging.


Scoliosis Child

Scoliosis Child. MRI Complete Spine Juvenile idiopathic scoliosis carries higher risk for intraspinal anomalies as compared with adolescent idiopathic scoliosis with a range of 13% to 27% [28-30]. Some suggest selective MRI for curve progression, neurologic status change, or routinely when surgical intervention is planned [30], or presurgically when there is back pain [9]. Other authors recommend total spine MRI for all patients with juvenile idiopathic scoliosis [28].


Scoliosis Child

Scoliosis Child. CT Spine CT does not play a significant role in the initial diagnostic assessment of early onset idiopathic scoliosis as it is limited with respect to intraspinal assessment.


Scoliosis Child

Scoliosis Child. Bone Scan Complete Spine Tc-99m MDP is not a primary imaging modality in the setting of early onset idiopathic scoliosis as it provides no intraspinal information.


Scoliosis Child

Scoliosis Child. Variant 3: Adolescent (10 to 17 years of age). Adolescent idiopathic scoliosis. No risk factors. Initial imaging. The body regions covered in this clinical scenario are the cervical, thoracic, and lumbar spine. These body regions might be evaluated separately or in combination as guided by physical examination findings, patient history, and other available information, including prior imaging.


Scoliosis Child

Scoliosis Child. Surgical decision making and planning is also influenced by the flexibility of the curves, which can be assessed using a variety of radiographic techniques, such as side bending, push prone, fulcrum bending, and traction radiographs [33-37]. Cheh et al [38] found that a single supine spine radiograph can predict curve type, flexibility, and structurality.


Scoliosis Child

Scoliosis Child. SOSORT suggests limiting spine radiographs to once every 12 months for adolescent patients at Risser stages 0 to 3 and every 18 months for patients at Risser stages 4 to 5 unless there are objective clinical changes in the appearance of the scoliosis [39].


Scoliosis Child

Scoliosis Child. CT Spine CT of the spine in adolescent idiopathic scoliosis is not routinely used in initial diagnostic assessment. Rather, some orthopedists use perioperative CT for presurgical planning and intraoperative navigation to optimize screw placement [16,17,40,41].


Scoliosis Child

Scoliosis Child. Bone Scan Complete Spine Tc-99m MDP is not a primary imaging modality in the setting of adolescent idiopathic scoliosis as it provides no intraspinal information.


Scoliosis Child

Scoliosis Child. Variant 4: Adolescent (10 to 17 years of age). Adolescent idiopathic scoliosis. Risk factors. Initial imaging. The body regions covered in this clinical scenario are the cervical, thoracic, and lumbar spine. These body regions might be evaluated separately or in combination as guided by physical examination findings, patient history, and other available information, including prior imaging.


Scoliosis Child

Scoliosis Child. Surgical decision making and planning is also influenced by the flexibility of the curves, which can be assessed using a variety of radiographic techniques, such as side bending, push prone, fulcrum bending, and traction radiographs [33-37]. Cheh et al [38] noted that a single supine spine radiograph can predict nonstructural minor curves as well.


Scoliosis Child

Scoliosis Child. SOSORT suggests limiting spine radiographs to once every 12 months for those adolescent patients at Risser stages 0 to 3 and every 18 months for patients at Risser stages 4 to 5, unless there are objective clinical changes in the appearance of the scoliosis [39].


Scoliosis Child

Scoliosis Child. MRI Complete Spine Up to 2% to 4% of adolescents with scoliosis have an intrinsic anomaly of their spinal cord or spinal contents that can only be identified with MRI [4,5]. The most common abnormalities revealed by MRI include Chiari I malformation, cord syrinx, cord tethering, and, more rarely, intrinsic spinal cord tumor [4,6]. Detecting these anomalies before scoliosis surgery may influence management [4,7,42]. However, there is no consensus on the


Scoliosis Child

Scoliosis Child. CT Spine CT of the spine in adolescent idiopathic scoliosis is not routinely used in initial diagnostic assessment. Rather, some orthopedists utilize perioperative CT for presurgical planning and intraoperative navigation to optimize screw placement [16,17,40,41].


Scoliosis Child


Scoliosis Child

Scoliosis Child. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.


Scoliosis Child

Scoliosis Child. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Palpable Abdominal Mass Suspected Neoplasm. Discussion of Procedures by Variant Variant 1: Palpable abdominal mass. Suspected intra-abdominal neoplasm. Initial imaging. Little has been written about the use of imaging in evaluating palpable abdominal masses since the 1980s. Newer reviews and case reports have focused on evaluation of specific masses using CT, ultrasound (US), and MRI. Radiography of the abdomen and fluoroscopy play a limited role in the diagnosis and workup of a palpable intra-abdominal mass.


Palpable Abdominal Mass Suspected Neoplasm. CT Abdomen There have been no recent studies on the diagnostic yield of CT for abdominal masses; however, it is widely used and assumed to be accurate in patients presenting with varying pathologies that may cause an abdominal mass [4- 7]. Most data on diagnostic accuracy stem from studies that are >30 years old. In a controlled trial from 1981 by Dixon et al [8], CT established diagnosis more quickly and reduced inpatient workup times in patients with abdominal masses when compared against conventional radiography and workup. In another study from 1984 by Williams et al [9], CT demonstrated high positive predictive value (99%) and negative predictive value (97%) for determining the presence or absence of a mass and correctly identified the organ of origin in 93% of patients with palpable abnormalities on clinical examination. The Dixon et al [8] study demonstrated that, compared with strategies not using CT, the use of CT can result in savings in time for diagnosis. Accordingly, when US findings are indeterminate, CT imaging should be obtained in a timely manner.


Palpable Abdominal Mass Suspected Neoplasm. Organomegaly (ie, enlargement of the liver, spleen, or kidneys), may present with a palpable mass. The differential diagnosis is lengthy, including lymphoma, primary organ disease, metastatic disease, extramedullary hematopoiesis, granulomatous disease, and infections. CT can provide clues to help narrow the differential


Palpable Abdominal Mass Suspected Neoplasm. aPanel Vice-Chair, Mallinckrodt Institute of Radiology, Saint Louis, Missouri. bVirginia Tech Carilion School of Medicine, Roanoke, Virginia. cPanel Chair, University of Wisconsin Hospital & Clinics, Madison, Wisconsin. dUniversity of Texas Health Science Center at Houston and McGovern Medical School, Houston, Texas; American Gastroenterological Association. eNewton-Wellesley Hospital, Newton, Massachusetts. fThe University of Texas MD Anderson Cancer Center, Houston, Texas; American College of Surgeons. gH. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida. hMassachusetts General Hospital, Boston, Massachusetts. iMedstar Georgetown University Hospital, Washington, District of Columbia. jCleveland Clinic, Cleveland, Ohio. kDuke University Medical Center, Durham, North Carolina. lEmory University, Atlanta, Georgia. mPenn State Health, Hershey, Pennsylvania. nUniversity of Alabama at Birmingham, Birmingham, Alabama. oBeth Israel Deaconess Medical Center, Boston, Massachusetts. pSpecialty Chair, Virginia Commonwealth University Medical Center, Richmond, Virginia.


Palpable Abdominal Mass Suspected Neoplasm. 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.


Palpable Abdominal Mass Suspected Neoplasm. Reprint requests to: publications@acr.org


Palpable Abdominal Mass Suspected Neoplasm. Palpable Abdominal Mass-Suspected Neoplasm diagnosis, although biopsy is often warranted [6,10]. CT is considered safe and effective for guiding percutaneous biopsies if the pathology can be visualized and the operator has knowledge of technical parameters, such as the need for breath holding, triangulation methods, gantry angling, and appropriate patient positioning [11-13]. There are no recent studies that specifically address the question of whether CT should be performed with or without intravenous (IV) contrast for a palpable mass. Acquisition of CT both with and without contrast does not generally add diagnostic value. Although available evidence and experience generally supports the appropriateness of CT with IV contrast over that of noncontrast CT for evaluation of intra-abdominal organs and pathology [12,14,15], the use of noncontrast CT may be of value in some circumstances.


Palpable Abdominal Mass Suspected Neoplasm. US Abdomen US has many positive attributes and is a useful tool for detecting and diagnosing potential intra-abdominal masses [4-6,16-19]. In a retrospective study including 104 patients with palpable masses referred for US evaluation, 69 had a correlative mass and US correctly identified the organ of origin in 88% of patients [17]. The 3 cases where the organ of origin was not positively identified were all masses arising in the pelvis (endometriosis, uterine fibroids, and ovarian tumor), which were later defined on CT. Despite the failure in these cases, the positive predictive value was 99% and negative predictive value 97% for identifying or excluding a mass. The one false- negative case was a patient with palpable mass on examination who had a negative US but subsequently positive CT demonstrating transverse colon cancer. The accuracy for identifying the organ of origin ranges from 88% to 91%, and 77% to 81% for correctly suggesting the underlying pathology [16,17,20,21].


Palpable Abdominal Mass Suspected Neoplasm. Although highly accurate, US visibility of the abdominal cavity may be limited because of bowel gas and body habitus. On the other hand, US has the benefit of real-time imaging. This can be very advantageous in the setting of palpable abnormality, providing additional information, such as tenderness, direct correlation, and dynamic changes like Valsalva maneuvers, when assessing for hernias. Studies have suggested that portable US units may improve diagnostic accuracy for detecting organomegaly [22] and may help to determine the need for additional diagnostic testing with a sensitivity of 91% and specificity of 83% [23]. US is considered highly useful for real- time guidance for biopsy and establishing definitive diagnosis [11,12].


Palpable Abdominal Mass Suspected Neoplasm. MRI Abdomen No comparative studies are available in the literature; however, there are several potential advantages to MRI that may advocate for its use in some instances. MRI possesses very high soft-tissue contrast, allowing depiction and differentiation of cystic structures, soft-tissue components, fat, and blood products [10]. This can be especially useful for defining benign from malignant lesions in organs such as the adrenal glands, kidneys, ovaries, and liver. Although MRI offers potential advantages, its exact performance in evaluating palpable masses relative to US and CT remains unclear given the absence of data; however, it is likely at least comparable. Although not always a first-line option, MRI can be very useful as a second-line imaging modality to further evaluate indeterminate masses detected on CT or US. Similar to CT, there is no evidence evaluating the utility and added benefit of IV contrast versus noncontrast MRI in the setting of a palpable intra-abdominal mass. Experience and evidence related to solid organ evaluation (liver, pancreas, and kidneys) suggests that IV contrast improves visualization of normal organs and pathology. However, there is some value in noncontrast MRI as it may still depict soft-tissue structures and delineate a mass.


Palpable Abdominal Mass Suspected Neoplasm. Radiography Abdomen Radiography is often not sufficient as a first step in evaluation of a palpable mass and hence the acquisition of cross-sectional imaging would likely be required for diagnosis regardless of the results of the radiograph [24,25]. Radiography may also be considered as a first step in rare situations. If the patient reports constipation, a radiograph could be used to confirm that diagnosis or to offer alternative diagnosis, such as bowel obstruction [26,27].


Palpable Abdominal Mass Suspected Neoplasm. Fluoroscopy Procedures (Contrast Enema, Upper GI Series, Small-Bowel Follow-Through) Fluoroscopy studies, such as contrast enema, upper gastrointestinal (GI) series, and small-bowel follow-through (SBFT), are usually not first-line imaging studies for palpable masses in adults. However, they may be used to further characterize associated degree of obstruction or abnormalities in GI function or transit [28]. As extraluminal findings are commonly not evaluated by contrast enema or upper GI series, additional imaging may be required even if an intraluminal mass is detected.


Palpable Abdominal Mass Suspected Neoplasm. Palpable Abdominal Mass-Suspected Neoplasm FDG-PET/CT Skull Base to Mid-Thigh In the absence of a known diagnosis, there is a very limited role for fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT in patients with palpable abnormalities. There is no literature to support its use as an initial imaging modality. The main role of FDG-PET/CT would be to stage a known neoplasm, potentially presenting with a new palpable abnormality.


Palpable Abdominal Mass Suspected Neoplasm. Variant 2: Palpable abdominal mass. Suspected abdominal wall mass. Initial imaging. The annual incidence of benign soft-tissue masses is approximately 3,000 per million population [29]. The rate of malignancy ranges from 5% to 42% in large series [30,31]. Clinical evaluation and history are important for developing a differential diagnosis, with features of large size, location within the abdominal cavity, growth, and recurrence at an excision site in a patient with a history of malignancy all raising suspicion of malignancy [31]. Imaging often plays a central role in further narrowing the differential diagnosis and guiding management. However, similar to Variant 1, there are few recent studies, and the overall quality of the literature is poor and primarily focused on specific disease processes rather than a diagnostic approach to palpable masses [32-36].


Palpable Abdominal Mass Suspected Neoplasm. The differential diagnosis related to the abdominal wall includes soft-tissue neoplasms of the skin, muscle, fat, bone, and vasculature. Additionally, hernias, congenital abnormalities, hematomas, and infections may present as abdominal wall masses. Differentiation of tissue components, such as blood products, fat, and vascularity, is important for narrowing the differential diagnosis and defining the relationship of the mass to tissue planes and structures is imperative in guiding management.


Palpable Abdominal Mass Suspected Neoplasm. US Abdomen Although no recent studies have evaluated the diagnostic accuracy of US specifically for abdominal wall masses, it is typically considered a first-line imaging modality [29,30,32]. This is due to the many advantages of US, such as capability of real-time imaging, Doppler evaluation of blood flow, and ability to assess for clinical features, such as tenderness. US can sometimes depict classic features of benign lesions, such as lipomas, desmoid tumors, vascular malformations, rectus sheath hematomas, infections, pseudoaneurysms, and endometriosis [30,32-34,36- 38]. However, in the setting of solid lesions, further workup and potentially tissue sampling is often needed. Although perhaps not widely used as a first-line imaging option, US can also confirm the presence of malignant masses, such as metastatic disease, sarcomas, and lymphomas. In a prospective study of 358 patients presenting with soft-tissue masses, US was performed as an initial imaging modality, yielding effective triage results with 100% specificity in referring indeterminate or potentially malignant masses on to more definitive imaging (MRI) and subsequent workup [31].


Palpable Abdominal Mass Suspected Neoplasm. In patients with suspected abdominal wall endometriosis, which presents as a mass in many instances, US correctly detected disease in approximately 97% of cases in a retrospective series of 151 patients evaluated surgically [36]. In a systematic review of the literature on abdominal wall endometriosis, the authors concluded that the overall quality of evidence is poor with no prospective studies; however, US or MRI can assist with localization and aid in surgical planning [39].


Palpable Abdominal Mass Suspected Neoplasm. US has several limitations. It can be less specific than other imaging modalities for characterizing masses [31]. US visibility of the abdominal wall is usually possible with few limitations. However, US may not provide details of deeper structures and relationship of masses to anatomic fascial planes. US also has advantages; it has the benefit of real-time imaging, such as assessing dynamic changes like Valsalva maneuvers, when evaluating for hernias. US is considered highly useful for real-time guidance for biopsy, but percutaneous biopsy should be considered carefully and in conjunction with oncologic specialist when a sarcoma is suspected [30].


Palpable Abdominal Mass Suspected Neoplasm. MRI Abdomen There is little recent literature on the diagnostic accuracy of MRI for abdominal wall mass evaluation. MRI acquired without and with IV contrast is recognized as a useful modality to further narrow the differential diagnosis of detected masses, because of its high soft-tissue contrast resolution, ability to differentiate fat and enhancement within structures, and sequences that identify iron and blood products that may aid in differential considerations, such as endometriosis or extramedullary hematopoiesis [10,35]. MRI acquired without and with IV contrast can depict specific imaging features for many entities, including endometriosis, simple lipomas, epidermoid cysts, desmoid tumors, and hematomas [38]. MRI acquired without IV contrast may also still depict soft-tissue structures and define anatomy/pathology. MRI may be a useful second-line examination, often recommended if a malignant or indeterminate mass is detected on US [29,30]. In a series of 126 consecutive cases


Palpable Abdominal Mass Suspected Neoplasm. Palpable Abdominal Mass-Suspected Neoplasm of fatty masses, MRI had a sensitivity of 100%, specificity of 83%, accuracy of 84%, and negative predictive value of 100% for differentiating simple lipoma from liposarcoma [40].


Palpable Abdominal Mass Suspected Neoplasm. Although helpful in defining relationship of masses to adjacent fascia, muscles, and vessels, MRI is often not specific enough to establish a definitive diagnosis, and biopsy or excision is usually required following consultation or referral by oncologic specialists [29,38].


Palpable Abdominal Mass Suspected Neoplasm. CT Abdomen There is little recent literature on the accuracy and diagnostic yield of CT for abdominal wall masses; however, CT is widely considered fast and accurate for excluding or confirming a mass. Because of the relative lack of soft- tissue resolution compared with MRI, it may not be a first- or second-line option for evaluation of abdominal masses. CT may be additionally helpful in the setting of suspected hernia, congenital abnormalities, hematomas, and infections [41,42]. Additionally, there may be a role in the setting of endometriosis for differentiation from other masses [43]. When malignant masses are suspected, CT may provide benefit of staging information related to metastatic disease in addition to defining the size, location, and relationship of a mass to adjacent structures.


Palpable Abdominal Mass Suspected Neoplasm. There are no recent studies that specifically address the question of whether CT should be performed with or without IV contrast for a palpable mass. Acquisition of CT both with and without contrast does not generally add diagnostic value. Although available evidence and experience generally supports the appropriateness of CT with IV contrast over that of noncontrast CT for evaluation of intra-abdominal organs and pathology [12,14,15], the use of noncontrast CT may be of value in some circumstances.


Palpable Abdominal Mass Suspected Neoplasm. CT may be of benefit in guiding biopsy and should be considered carefully and in conjunction with oncologic specialist when a sarcoma is suspected [30].


Palpable Abdominal Mass Suspected Neoplasm. FDG-PET/CT Skull Base to Mid-Thigh In the absence of a known diagnosis, there is a very limited role for FDG-PET/CT in patients with palpable abnormalities. There is no literature to support its use as an initial imaging modality. The main role of FDG- PET/CT would be to stage a known neoplasm, potentially presenting with a new palpable abnormality.


Palpable Abdominal Mass Suspected Neoplasm. Radiography Abdomen Radiography plays a very limited role in evaluation of abdominal wall masses. There may be a role if there is suspicion of an osseous lesion arising from the rib, vertebral bodies, or pelvic bones.


Palpable Abdominal Mass Suspected Neoplasm. Fluoroscopy Procedures (Contrast Enema, Upper GI Series, Small-Bowel Follow-Through) There is no literature to support the use of fluoroscopy for primary evaluation of suspected abdominal wall masses. Even if there is clinical suspicion for bowel herniation, US may be a better first-line imaging modality.


Palpable Abdominal Mass Suspected Neoplasm. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.


Palpable Abdominal Mass Suspected Neoplasm. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. Twins As an independent marker of fetal aneuploidy, nuchal translucency is particularly useful in twins because of the inability of maternal serum markers or age to identify the fetus at risk. Nuchal translucency measurement allows each fetus of a twin pregnancy to be assessed individually; the distribution of measurements does not differ significantly between singletons and twins so that standard thresholds can be used [9,10]. In dichorionic twins, fetus-specific risks are calculated on the assumption each twin has an independent risk reflected by its own nuchal translucency [2,11,12]. In monochorionic twins, a pregnancy-specific risk is calculated using the average nuchal translucency thickness of both fetuses [2,13]. As in singletons, increased nuchal translucency may also be a marker of fetal structural anomalies, genetic syndromes, and intrauterine demise in twins.


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. 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.


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. Reprint requests to: publications@acr.org


Nuchal Translucency Evaluation

Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. Nuchal Translucency Evaluation


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. Special Imaging Considerations Measurement of the nuchal translucency has been standardized in order to improve its performance in screening for fetal aneuploidy. Quality assurance programs for nuchal translucency assessment have been established by the Fetal Medicine Foundation in London and the Nuchal Translucency Quality Review in the United States. The ACR Appropriateness Criteria methodology assumes that each imaging procedures is performed and interpreted by an expert, but it should be noted that there remains considerable inter- and intra-observer variability in nuchal translucency measurements, highlighting the importance of ongoing quality assessment [14,15].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. First trimester screening algorithms can be improved by assessing for the presence or absence of the nasal bone and adjusting aneuploidy risk calculations accordingly [16]. The absence of the nasal bone at 11 to 14 weeks is another powerful US marker of fetal aneuploidy; it improves the performance of early screening by decreasing the false- positive rate to 2.5% [16]. Other first trimester US markers of fetal aneuploidy such as increased frontomaxillary facial angle, an aberrant right subclavian artery, presence of tricuspid regurgitation, reversed a-wave in the ductus venosus, and increased iliac wing angle have not been incorporated into routine screening algorithms and their clinical usefulness in the general population remains uncertain [17]. The role of nuchal translucency measurement in the new era of cell-free fetal DNA screening is also uncertain. It is recommended that a first trimester US for the sole purpose of nuchal translucency screening not be performed in patients with negative cell-free fetal DNA [18].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. OR Discussion of Procedures by Variant Variant 1: Routine nuchal translucency measurement at 11 to 14 weeks of gestation for single or twin gestations. Initial imaging. US Duplex Doppler Pregnant Uterus Although the utility of Doppler imaging has been investigated in research protocols, there is no literature to support a recommendation to universally incorporate Doppler studies into routine first trimester screening algorithms for fetal aneuploidy [17]. Given the theoretical risk of thermal damage to the developing fetus from the use of color and pulsed Doppler US, its use is not advised when the nuchal translucency is of normal thickness or below the threshold of 3 mm at 11 to 14 weeks of gestation [2,19].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. US Echocardiography Fetal In the absence of other maternal or fetal risk factors, there is no literature to support the routine use of fetal echocardiography in patients with normal nuchal translucency measurements at 11 to 14 weeks of gestation [20].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. US Pregnant Uterus Transabdominal ACOG recommends aneuploidy screening or diagnostic testing be offered to all women in early pregnancy [2]. For women who choose screening over invasive diagnostic testing, first trimester combined screening with nuchal translucency and maternal serum markers remains a reasonable option for single and twin gestations [2,18,21]. Although ACOG does not endorse a specific screening test, citing that no one screening test is superior to another in all test characteristics, there are several benefits of first trimester screening, including maternal privacy, early reassurance, and timely detection of fetal abnormalities with the option for earlier and safer pregnancy termination [2]. Using the nuchal translucency measurement and maternal serum pregnancy-associated plasma protein A and free beta subunit of human chorionic gonadotropin levels, most laboratories will report specific risk estimates for trisomy 21, 18, and 13 after adjusting for crown-rump length and maternal factors such as age, prior history of aneuploidy, weight, and race [2]. In clinical practice, first trimester combined screening for aneuploidy detects about 90% of affected pregnancies at a false positive rate of 5% for single gestations with slightly lower sensitivities reported for twins [12,17].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. US Pregnant Uterus Transvaginal Transvaginal US may be utilized for first trimester aneuploidy screening if optimal views of the nuchal translucency cannot be obtained using the transabdominal approach, which occurs in about 5% of patients [5,24,28]. The higher resolution of transvaginal US can be particularly helpful when imaging women with high body mass indexes. The transvaginal approach may also be favored in patients with multiple abdominal surgeries or presenting with a transverse fetal lie in the lower aspect of the uterus. However, reduced probe mobility limits the available image planes, so using a combination of transabdominal and transvaginal US may be necessary to fully assess the first trimester fetus. Fetal nuchal translucency measurements are similar whether measured by transabdominal or transvaginal US as long as the same principles for image acquisition and nuchal translucency measurement are applied [29].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. The transvaginal approach may produce better quality images to assess the nasal bone than transabdominal US [65]. However, perhaps because of the restricted range of movement, a 3-fold higher failure of nasal bone imaging has been reported with transvaginal US [30]. If there is difficulty obtaining the nuchal translucency measurement, there is likely to be difficulty in obtaining the proper image to assess for the presence or absence of nasal bone regardless of approach.


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. The ductus venosus can be easily identified by its accelerated flow velocity on color Doppler and then interrogated with pulsed Doppler to assess its flow characteristics. The triphasic waveform of the ductus venosus, reflecting the phases of the cardiac cycle, normally has forward flow toward the heart at all times; a reversed a-wave, corresponding to retrograde flow during atrial contraction, is abnormal. Although the cause of this abnormality in fetal aneuploidy is uncertain, a reversed a-wave is seen in 3% to 4% of euploid fetuses compared to about 70% of trisomy 21 and trisomy 18, 65% of trisomy 13, and 75% of Turner syndrome fetuses [34]. The addition of ductus venosus Doppler assessment to nuchal translucency measurement improves the detection rate of trisomy 21 to 96% with 3% false positive rate [34]. Ductus venosus a-wave abnormalities are also associated with congenital heart disease [35]. In chromosomally normal fetuses with an increased nuchal translucency, a reversed a-wave in the ductus venosus is associated with a 3-fold increase in the likelihood of a major heart anomaly; a normal ductus


Nuchal Translucency Evaluation


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. The risk of an adverse pregnancy outcome is proportional to the degree of nuchal translucency enlargement; there is an increased risk of intrauterine demise in fetuses with large nuchal translucencies, even in the absence of associated chromosomal or structural abnormalities [22,23]. Although there are no studies that specifically address the optimal management of these pregnancies after the initial US evaluation and diagnostic testing, serial fetal surveillance is usually added to routine prenatal care with periodic US examinations to monitor fetal growth and well-being [2,45].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. US Pregnant Uterus Transvaginal A transvaginal US may be advantageous in patients with an increased nuchal translucency, particularly if planning to assess for additional first trimester markers of fetal aneuploidy or screen for major anomalies in women with increased body mass indexes, abdominal wall scarring, or fetal positioning in the lower uterus. Fetal nuchal translucency measurements are similar as long as the same principles for image acquisition are applied, so obtaining a transvaginal measurement is not required if transabdominal imaging is satisfactory [29]. However, high resolution transvaginal US may more clearly identify the amnion and nuchal translucency borders to ensure an accurate maximal measurement in patients with suboptimal transabdominal views.


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. US Echocardiography Fetal An increased nuchal translucency in a dichorionic twin is an indication to obtain a fetal echocardiogram [20]. Performing fetal echocardiography on twins is challenging because of both maternal factors, such as increased body mass index or inability to rest comfortably during a lengthy examination, and fetal factors, such as unfavorable fetal position or limited views due to the presence of a co-twin. Although early fetal echocardiography may be attempted, a standard fetal echocardiogram at 18 to 22 weeks with an expected detection rate of over 80% for major cardiac anomalies is recommended when increased nuchal translucency is detected in dichorionic twins [26,44].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. One of the advantages of nuchal translucency screening in dichorionic twins is the ability to perform individual measurements on each fetus and generate fetus-specific risks [45]. The management of a positive screen or an increased nuchal translucency is similar in twins and singletons; genetic counseling, diagnostic testing, and in continuing pregnancies with a history of increased nuchal translucency or diagnosed with fetal aneuploidy, a detailed anatomic survey, and fetal echocardiography in the second trimester are recommended. The prevalence of increased nuchal translucency in dichorionic twins with a normal karyotype is similar to that in singletons [56]. Although an individual risk can be estimated for each twin and a patient may opt for only sampling the twin suspected to be at risk, it is customary to sample both twins at the time of diagnostic testing to avoid a missed diagnosis because of averaged maternal biochemistries or incorrect assignment of chorionicity [57]. For those who decline diagnostic testing, an evaluation for additional first trimester markers of fetal aneuploidy such as the presence or absence of the nasal bone may assist in patient counseling; however, nasal bone assessment is more challenging in twin pregnancies [58].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. After the second trimester anatomy survey and fetal echocardiogram, there are no robust evidence-based recommendations for the US follow-up of dichorionic twins with increased nuchal translucency. However, given the risk for intrauterine demise, it is reasonable that serial surveillance of fetal growth and well-being be performed in the third trimester [45,59,60].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. US Pregnant Uterus Transvaginal As in singleton pregnancies, transvaginal US can be utilized at 11 to 14 weeks of gestation to assess the nuchal translucency, additional markers of aneuploidy, as well as early fetal anatomy in dichorionic twins. Fetal nuchal translucency measurements are similar as long as the same principles for image acquisition and measurement are employed [29]. Given the larger uterine dimensions from the presence of two fetuses, two sacs of amniotic fluid, and two placentas, a combination of both transabdominal and transvaginal imaging may be optimal to fully assess dichorionic twins with increased nuchal translucency.


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. Variant 4: Increased nuchal translucency in monochorionic twins at 11 to 14 weeks of gestation. US Duplex Doppler Pregnant Uterus The detection of abnormal flow across the tricuspid valve or in the ductus venosus by color and pulsed Doppler increases the likelihood of fetal aneuploidy in monochorionic twins with increased nuchal translucency. In addition, both reversed or absent a-waves in the ductus venosus have been reported to be markers for congenital heart disease and the development of twin-twin transfusion syndrome later in gestation [61,62]. Although Doppler imaging is likely of little to no value in uncomplicated monochorionic twins, serial assessment of the ductus venosus, umbilical artery and vein, and middle cerebral artery may be useful in cases complicated by unequal placental sharing, twin- twin transfusion syndrome, or twin anemia polycythemia sequence [45].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. US Echocardiography Fetal Because of the substantial risk of congenital heart disease, there is strong evidence to support the use of fetal echocardiography for all monochorionic twins, regardless of the nuchal translucency measurement [20]. The overall risk of congenital heart disease in monochorionic twins is 2%, double the background risk of a singleton, and increases to 5% in cases of twin-twin transfusion syndrome, particularly among recipient twins [63]. Recipient twins often demonstrate evidence of volume overload with increased pulmonary and aortic velocities, cardiomegaly, and atrioventricular regurgitation, which, over time, can result in biventricular hypertrophy and diastolic dysfunction [64]. Poor right ventricular systolic function can lead to functional right ventricular outflow tract obstruction in up to 10% of recipient twins, which may progress to severe pulmonic stenosis and a poor prognosis [64]. In contrast, recipient twins with normal cardiac function have improved survival [65]. Therefore, in addition to excluding structural heart defects in monochorionic twins, fetal echocardiography with a detailed functional assessment may be useful in identifying cases of twin-twin transfusion syndrome that would benefit from fetoscopic laser therapy and in evaluating the response to treatment. Although an increased nuchal translucency may prompt early echocardiography in monochorionic twins, standard second trimester fetal echocardiography is warranted in all monochorionic twins because of the substantial risk of both structural and functional heart abnormalities regardless of the nuchal translucency measurements [59,65].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. US Pregnant Uterus Transabdominal First trimester combined screening with nuchal translucency and maternal serum markers is currently a common choice for aneuploidy screening in monochorionic twins [53,54]. In monochorionic twins, each fetus is assumed to have the same risk of aneuploidy equivalent to the maternal age risk of a singleton. Therefore, aneuploidy risk estimates for trisomy 21, 18, and 13 are calculated using the mean nuchal translucency measurement of the twins, usually obtained via transabdominal US. Overall, first trimester combined screening in monochorionic twins provides detection rates of fetal aneuploidy similar to that reported in singletons but with a higher false positive rate [11,53]. A meta-analysis of first trimester combined aneuploidy screening reported a sensitivity of 87.4% for monochorionic twins compared to 86.2% for dichorionic twins [54]. Nuchal translucency measurements have been observed to be higher in monochorionic twins compared to dichorionic twins, which may explain the higher false- positive rate of aneuploidy screening in monochorionic twin pregnancies. In monochorionic twins with increased nuchal translucency thickness, an assessment for additional first trimester markers of fetal aneuploidy, such as the absence of the nasal bone, may be helpful to patients trying to decide whether to undergo invasive diagnostic testing [58]. Increased nuchal translucency thickness in a monochorionic twin may also be an early manifestation of inter- fetal transfusion and early hypervolemic congestion in a recipient twin. Indeed, both nuchal translucency abnormalities and crown-rump length discrepancies have been associated with an increased risk of twin-twin


Nuchal Translucency Evaluation

Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. Nuchal Translucency Evaluation


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. transfusion syndrome [66-68]. A crown-rump discrepancy of >10% is associated with almost a doubling the risk of developing twin-twin transfusion syndrome [67,68]. Nuchal translucency discordance >20% has been associated with a >30% risk of severe twin-twin transfusion syndrome and early fetal death compared with a <10% risk when the discordance is <20% [69].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. As in singletons and dichorionic twins, an increased nuchal translucency in monochorionic twins is associated with fetal aneuploidy, genetic syndromes, structural anomalies, and intrauterine demise. Genetic counseling, invasive diagnostic testing, fetal anatomic surveys, and fetal echocardiography are recommended in monochorionic twin pregnancies complicated by increased nuchal translucency thickness affecting one or both twins. Serial US surveillance of monochorionic twins is advised because of complications associated with sharing a single placenta such as twin-twin transfusion syndrome, unequal placental sharing with discordant twin growth and selective intrauterine growth restriction, and twin anemia polycythemia sequence [64,70]. Because of these unique complications, women with monochorionic pregnancies are followed more closely than dichorionic pregnancies; serial US evaluations every 2 weeks starting at 16 weeks until delivery should be considered [45]. Despite its potential value, a recent review concluded that it is not currently possible to predict adverse outcomes in monochorionic twin pregnancies based on nuchal translucency assessment alone [71].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. US Pregnant Uterus Transvaginal Transvaginal US at 11 to 14 weeks may be utilized to assess nuchal translucency, additional first trimester markers of aneuploidy, early anatomy, and cardiac structure in monochorionic twins when acceptable images cannot be obtained transabdominally. Fetal nuchal translucency measurements are comparable between transabdominal and transvaginal US as long as the same principles for image acquisition and measurement are followed [29].


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. Summary of Recommendations Variant 1: US pregnant uterus transabdominal is usually appropriate for the initial imaging of routine nuchal translucency measurement at 11 to 14 weeks of gestation for single or twin gestations.


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Nuchal Translucency Evaluation


Nuchal Translucency Evaluation at 11 to 14 Weeks Gestational Age. References 1. Pandya PP, Brizot ML, Kuhn P, Snijders RJ, Nicolaides KH. First-trimester fetal nuchal translucency thickness


Preprocedural Planning for Transcatheter Aortic Valve Replacement. Introduction/Background Transcatheter aortic valve replacement (TAVR) has dramatically impacted the management of high-risk surgical patients [1-10], as well as medium- and low-risk patients [11], for the treatment of aortic valve disease. TAVR is a less invasive route (percutaneous endovascular) to position a prosthesis at the aortic annulus that displaces the native aortic valve leaflets toward the aortic wall. Procedure-related complications [3,5,7,8] are linked to inaccurate estimates of annular geometry; unlike surgical aortic valve replacement, the aortic annulus is not directly inspected by the proceduralist at the time of the procedure, and multiple parameters related to the annulus should be measured. Because the annulus has a complex geometry, volumetric data have emerged with standardized reformatting along patient-specific anatomic planes for annular assessment and device sizing [1,2,4,9,10,12-26]. Accurate measurements guide optimal choices for device sizing and deployment, with a secondary reduction in TAVR-related complications. The catheter-based system ranges in size between 14 and 24 Fr with transfemoral, transaxillary, and transaortic as well as direct aortic and left ventricular approaches reported; the entire aorta and branches to potential access points are evaluated for the presence, burden, and distribution of peripheral vascular atherosclerosis.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. This document does not elucidate the diagnosis of aortic valve disease, surgical risk stratification, [27-32] or the assessment of coronary artery disease. It is presumed that patients considered in this document are candidates for TAVR. Also, the panel did not consider planning done at the time of intervention with either catheter angiography, echocardiography, or a combination of both.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. For this document, the panel only considered the 2 clinical tasks required for preprocedure screening: (Variant 1) assessment of aortic annulus and aortic root, to help guide the choice of the valve prosthesis, and (Variant 2) assessment of supravalvular aorta and vascular access for potential determination of vascular access site and road mapping the desired device delivery.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. Special Imaging Considerations For the purposes of distinguishing between CT and CT angiography (CTA), ACR Appropriateness Criteria topics use the definition in the ACR-NASCI-SIR-SPR Practice Parameter for the Performance and Interpretation of Body Computed Tomography Angiography (CTA) [33]:


Preprocedural Planning for Transcatheter Aortic Valve Replacement. All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/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.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. aMassachusetts General Hospital and Harvard Medical School, Boston, Massachusetts. bResearch Author, South Texas Radiology Group, P.A., San Antonio, Texas. cUniversity of Michigan, Ann Arbor, Michigan. dPanel Chair, Brigham & Women's Hospital, Boston, Massachusetts. ePanel Chair, Cleveland Clinic, Cleveland, Ohio. fPanel Vice-Chair, Mayo Clinic, Rochester, Minnesota. gKnight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon; Society of Cardiovascular Computed Tomography. hSanger Heart and Vascular Institute, Charlotte, North Carolina; American Society of Echocardiography. iUT Southwestern Medical Center, Dallas, Texas; Commission on Nuclear Medicine and Molecular Imaging. jUniversity of Washington School of Medicine, Seattle, Washington; Society for Cardiovascular Magnetic Resonance. kEmory University, Atlanta, Georgia; Committee on Emergency Radiology-GSER. lWashington University School of Medicine, Saint Louis, Missouri; American Association for Thoracic Surgery. mCleveland Clinic, Cleveland, Ohio. nStanford University, Stanford, California. oMercyhealth, Rockford, Illinois. pSpecialty Chair, Duke University Medical Center, Durham, North Carolina. qSpecialty Chair, Brigham & Women's Hospital, Boston, Massachusetts.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. 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.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. Reprint requests to: publications@acr.org


Transcatheter Aortic Valve Replacement

Preprocedural Planning for Transcatheter Aortic Valve Replacement. Transcatheter Aortic Valve Replacement


Preprocedural Planning for Transcatheter Aortic Valve Replacement. Imaging should allow characterization and reporting of aortic valve morphology in each patient and degree of calcification [34,35]. Calcified raphe for bicuspid valves and excess leaflet calcification are known to be associated with an increased risk of procedural complications and midterm mortality [36]. The annulus size for bicuspid aortic valve should be measured and reported in the same fashion as for tricuspid aortic valves, even though the basal attachments of the 2 leaflets of bicuspid aortic valve provide only 2 landmarks out of a necessary 3 landmarks to define an annular plane in space [37]. In addition, it is important to evaluate coronary ostial heights, sinus of Valsalva widths, sinotubular junction diameters, and annular/left ventricular outflow tract (LVOT) calcification, all of which are predictive of complication risks with TAVR.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. OR Discussion of Procedures by Variant Variant 1: Preintervention planning for transcatheter aortic valve replacement: assessment of aortic root. Initial imaging. Aortography Chest There is no relevant literature to support the use of aortography chest for annulus sizing and assessment of aortic root.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Chest With IV Contrast There is no relevant literature to support the use of chest CT with intravenous (IV) contrast for annulus sizing and assessment of aortic root.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Chest Without and With IV Contrast There is no literature in support of chest CT without and with IV contrast for annular sizing and assessment of aortic root.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Chest Without IV Contrast There is no literature in support of chest CT without IV contrast for annular sizing and assessment of aortic root. Aortic calcification can; however, be assessed on CT chest without IV contrast. Harbaoui et al [38] evaluated ascending aortic calcifications in 189 patients undergoing TAVR and noted ascending aortic calcification (tertile 3 versus tertile 1) appeared predictive of heart failure (hazard ratio [HR]: 2.29; 95% confidence interval [CI], 1.12- 4.66; P = .023).


Preprocedural Planning for Transcatheter Aortic Valve Replacement. Transcatheter Aortic Valve Replacement (14% versus 35%; P = .003). In a prospective study of 266 patients, 133 consecutive patients underwent TAVR with valve prosthesis size recommendation based on a CTA sizing algorithm and were compared with another cohort of 133 consecutive patients who underwent TAVR with valve prosthesis size recommendation based on a combination of echocardiogram measurements and angiographic images. The authors demonstrated a significant reduction in the incidence of paravalvular leak of 5.3% (7/133) in the CT group and 12.8% (17/133) in the control group (P = .032) as a primary endpoint and aortic annulus rupture, and they demonstrated a significant reduction in in-hospital deaths of 3.8% (5/133) in the CTA group and 11.3% (15/133) in the control group (P = .02) as a secondary endpoint [15].


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CTA Chest With IV Contrast There is no literature to support the use of CTA chest with IV contrast for the assessment of the aortic root; however, in absence of motion artifacts, the annulus can be evaluated for size, calcifications, coronary ostial heights, and sinus of Valsalva diameters.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CTA Coronary Arteries With IV Contrast There is no relevant literature to support the use of CTA coronary arteries with IV contrast as the initial imaging modality for the assessment of aortic root. Although CTA coronary arteries with IV contrast can evaluate coronary anatomy and stenosis, which can be helpful in the management of patients undergoing TAVR, it does not impact selection of device type and/or size. A multiphase coronary CTA can also be used for evaluation and sizing of the annulus and aortic root.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. MRA Chest With IV Contrast Although a majority of the evidence focuses on noncontrast MR angiography (MRA) techniques for root assessment, contrast-enhanced MRA may provide faster acquisition [45].


Preprocedural Planning for Transcatheter Aortic Valve Replacement. MRA Chest Without and With IV Contrast In a prospective study of 69 patients, Ruile et al [46] observed good reproducibility of aortic annulus dimensions and calcifications in comparison with cardiac CTA, even in the presence of arrhythmias in the all-comers pre-TAVR population and useful in patients at an increased risk for contrast-induced nephropathy with an agreement for hypothetical prosthesis sizing in 63 of 67 (94%) patients for systolic CTA and modeled systolic MRA. Also, excellent correlation was reported for the distance to the right or left coronary ostium between diastolic CTA and diastolic MRA.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. The role of MRA is; however, limited when there is a high-susceptibility artifact, magnetic field incompatible devices, and severe arrhythmia. Finally, the MRA examination is a technically more complex examination, with longer study time and a higher required degree of patient cooperation, which can be problematic for patients with a poor clinical condition [47].


Preprocedural Planning for Transcatheter Aortic Valve Replacement. MRA Coronary Arteries Without and With IV Contrast There is no relevant literature to support the use of MRA coronary arteries without and with IV contrast as the initial imaging modality for the assessment of aortic root.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. Transcatheter Aortic Valve Replacement MRA Coronary Arteries Without IV Contrast There is no relevant literature to support the use of MRA coronary arteries without IV contrast as the initial imaging modality for the assessment of aortic root.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. Transcatheter Aortic Valve Replacement US Echocardiography Transesophageal In a retrospective analysis of 101 patients who underwent both preoperative MDCT and 3-D TEE for aortic annulus sizing for TAVR planning, the automatic software measurements showed very good agreement with manual values obtained using MDCT and 3-D TEE, with the interactive approach having slightly narrower limits of agreement. The latter also had excellent intra- and interobserver variability. Both fully automatic and interactive analyses showed excellent test-retest reproducibility, with the first having a faster analysis time. Finally, either approach led to good sizing agreement against the true implanted sizes (>77%) and against MDCT-based sizes (>88%) [53].


Preprocedural Planning for Transcatheter Aortic Valve Replacement. A retrospective analysis of 31 patients who underwent transcatheter aortic valve implantation showed an excellent correlation between the aortic annulus measurements obtained by both manual 3-D TEE method and by the automatic software method (intraclass correlation coefficient: 0.731 (0.508-0.862), r: 0.742) for aortic annulus diameter and (intraclass correlation coefficient: 0.723 (0.662-0.923), r: 0.723) for the aortic annulus area, with no significant differences regardless of the method used. The interobserver variability was superior for the automatic measurements than for the manual ones. In a subgroup of 10 patients, they also found an excellent correlation between the automatic measurements and those obtained by MDCT (intraclass correlation coefficient: 0.941 (0.761- 0.985), r: 0.901) for aortic annulus diameter and (intraclass correlation coefficient: 0.853 (0.409-0.964), r: 0.744) for the aortic annulus area. Thus, new automatic 3-D TEE software allows modeling and quantifying the aortic root from 3-D TEE data with high reproducibility and showed good correlation between the automated measurements and other 3-D validated techniques, thus supporting its use in clinical practice as an alternative to MDCT before transcatheter aortic valve implantation for annular sizing (annular area, annular mean diameter and perimeter, sinotubular junction diameter, sinus of Valsalva diameter) [54]. Although TEE can be used intraprocedurally, it has a limited role for preprocedural assessment. Additionally there is a paucity of TEE data for evaluating aortic root features such as coronary ostial height and subannular calcification [55].


Preprocedural Planning for Transcatheter Aortic Valve Replacement. US Echocardiography Transthoracic Resting Although ultrasound (US) echocardiography transthoracic resting can diagnose aortic stenosis and can be used during TAVR procedures, there is no relevant literature to support its use for annulus sizing and assessment of aortic root.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. Variant 2: Preintervention planning for transcatheter aortic valve replacement: assessment of supravalvular aorta and vascular access. Initial imaging. Aortography Chest, Abdomen, and Pelvis There is no relevant literature to support the use of aortography of the chest, abdomen, and pelvis as the initial imaging modality for the evaluation of vascular access before a TAVR procedure.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Abdomen and Pelvis With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis with IV contrast as the initial imaging modality for the valuation of vascular access for a TAVR procedure.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without and with IV contrast as the initial imaging modality for evaluation of vascular access for a TAVR procedure.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Abdomen and Pelvis Without IV Contrast CT abdomen and pelvis without IV contrast cannot assess lumen size and patency, but mural calcifications can be assessed. In a comparative study of 103 of 588 patients undergoing both noncontrast CT and angiography, with 17 sheath-related complications, Okuyama et al [23] showed there was no difference between noncontrast CT and angiography: area under the curve 0.79 (95% CI, 0.70-0.86) versus area under the curve 0.73 (95% CI, 0.63-0.81) in predicting sheath-related complications.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Chest, Abdomen, and Pelvis With IV Contrast There is no relevant literature to support the use of CT chest, abdomen, and pelvis with IV contrast as the initial imaging modality for the evaluation of vascular access before a TAVR procedure.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Chest, Abdomen, and Pelvis Without and With IV Contrast There is no relevant literature to support the use of CT chest, abdomen, and pelvis without and with IV contrast as the initial imaging modality for the evaluation of vascular access before a TAVR procedure. Aortic calcification can: however, be assessed on CT chest, abdomen, and pelvis without and with IV contrast. Harbaoui et al [38] evaluated 189 patients undergoing TAVR for total aortic calcifications, ascending aortic calcification, descending


Preprocedural Planning for Transcatheter Aortic Valve Replacement. Transcatheter Aortic Valve Replacement aorta calcifications, and abdominal aorta calcifications. In their study, total aortic calcification (tertile 3 versus tertile 1) was significantly and strongly associated with cardiac mortality (HR: 16.74; 95% CI, 2.21-127.05; P = .006) and all-cause mortality (HR: 2.39; 95% CI, 1.18-4.84; P = .015). Each aortic calcified segment was associated with cardiac mortality, whereas only ascending aortic calcification (tertile 3 versus tertile 1) appeared predictive of heart failure (HR: 2.29; 95% CI, 1.12-4.66; P = .023).


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Chest, Abdomen, and Pelvis Without IV Contrast There is no relevant literature to support the use of CT chest, abdomen, and pelvis without IV contrast as the initial imaging modality for the evaluation of vascular access before a TAVR procedure. CT chest, abdomen, and pelvis without IV contrast cannot assess lumen size and patency, but mural calcifications can be assessed.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Chest With IV Contrast There is no relevant literature to support the use of CT chest with IV contrast as the initial imaging modality for the evaluation of vascular access before a TAVR procedure.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast as the initial imaging modality for the evaluation of vascular access before a TAVR procedure.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Chest Without IV Contrast There is no relevant literature to support the use of CT chest without IV contrast as the initial imaging modality for the evaluation of vascular access before a TAVR procedure. CT chest without IV contrast cannot assess lumen size and patency, but mural calcifications can be assessed. Additionally, circumferential aortic calcifications (porcelain aorta) can be detected, which may complicate the device delivery [56].


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CT Heart Function and Morphology With IV Contrast There is no relevant literature to support the use of CT heart function and morphology with IV contrast as the initial imaging modality for the evaluation of vascular access before a TAVR procedure. Preprocedural CT heart function and morphology with IV contrast can help in identifying left ventricular apex and assess myocardial thickness and left ventricular orientation and in guiding planned mini-thoracotomy.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CTA Abdomen and Pelvis With IV Contrast CTA imaging can assess luminal size, patency, vessel tortuosity, and the extent of mural calcifications. Kinnel et al [57] evaluated aortoiliac and femoral arteries in their comparative study of 175 patients for abdominal aortic tortuosity and noted abdominal aorta tortuosity in 28 patients (16%) with strong association with the occurrence of a complication (adjusted odds ratio 2.7; 95% CI, 1.1-6.6; P = .03).


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CTA Chest, Abdomen, and Pelvis With IV Contrast CTA allows the assessment of vessel size, calcifications, and minimal luminal diameters [58]. In a comparative study of 283 of 588 patients undergoing both contrast CT and angiography, with 35 sheath-related complications, Okuyama et al [23] showed a greater predictive value for vascular complications with contrast CT than angiography by area under the curve (P < .001): 0.87 (95% CI, 0.82-0.91) versus 0.72 (95% CI, 0.66-0.77). Recent data from the VICTORY registry of 240 patients also showed a role of CTA in assessing tortuosity. In the study, the authors noted a higher incidence of access and bleeding complications in patients with a higher iliofemoral tortuosity score (56 [36.8%] versus 17 [19.3%]; P = .003). Additionally, in a multivariate logistic regression analysis, only the higher iliofemoral tortuosity score was a significant predictor of the primary endpoint (odds ratio, 2.11; 95% CI, 1.09-4.05; P = .026) [59].


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CTA can also be used to evaluate alternate access sites like direct aortic or subclavian/axillary access. Arnett et al [60] retrospectively evaluated 208 patients undergoing CTA and reported on the compared axillary arteries and demonstrated substantially lower rates of significant stenosis (2% versus 12%, P < .01) and significantly lower rates of moderate to severe calcification disease (9% versus 64%, P < .01) than iliofemoral arteries.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. CTA Chest With IV Contrast CTA of the chest with IV contrast is helpful for patients undergoing TAVR [49] for the assessment of supravalvular aorta. It has been demonstrated that a subclavian approach leads to morbidity and mortality rates similar to those observed with the transfemoral approach [61]. CTA can also be used to evaluate alternate access sites like direct aortic or subclavian/axillary access. Arnett et al retrospectively evaluated 208 patients undergoing CTA and reported on the compared axillary arteries and demonstrated substantially lower rates of significant stenosis (2%


Preprocedural Planning for Transcatheter Aortic Valve Replacement. Transcatheter Aortic Valve Replacement versus 12%, P < .01) and significantly lower rates of moderate to severe calcification disease (9% versus 64%, P < .01) than iliofemoral arteries [60].


Preprocedural Planning for Transcatheter Aortic Valve Replacement. MRA Abdomen and Pelvis Without and With IV Contrast There is limited data supporting MRA abdomen and pelvis without and with IV contrast as the initial imaging modality for the evaluation of vascular access before a TAVR procedure.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. MRA Chest, Abdomen, and Pelvis With IV Contrast There is no relevant literature supporting the use of MRA chest, abdomen, and pelvis with IV contrast for the assessment of supra ventricular aorta and vascular access. MRA chest, abdomen, and pelvis with IV contrast can; however, be used as an alternate option in a selected patient population to assess supravalvular aorta and vascular access.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. MRA Chest With and Without IV Contrast There is no relevant literature supporting the use of MRA chest with and without IV contrast for the assessment of supra ventricular aorta and vascular access; however, MRA chest with and without IV contrast can be used as an alternate option in a selected patient population to assess supravalvular aorta and vascular access.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. US Duplex Doppler Chest, Abdomen, and Pelvis There is no relevant literature to support the use of US duplex doppler chest, abdomen, and pelvis as the initial imaging modality for evaluation of vascular access before a TAVR procedure.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. US Echocardiography Transesophageal There is no relevant literature to support the use of TEE as the initial imaging modality for the evaluation of vascular access before a TAVR procedure.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. US Echocardiography Transthoracic Resting There is no relevant literature to support the use of TTE resting as the initial imaging modality for the evaluation of vascular access before a TAVR procedure.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. US Intravascular Aorta and Iliofemoral System Although US can be used to assist in arterial puncture and serve as a roadmap during the TAVR procedure, there is limited relevant literature to support the use of US intravascular aorta and iliofemoral system as the imaging modality for evaluation of the vascular access before a TAVR procedure. In an observational study, Essa et al [63] evaluated 15 patients and observed strong correlation between intravascular US and CTA for minimum luminal diameter (r = 0.62). Concordance was also strong between CTA and invasive iliofemoral angiography for the assessment of tortuosity (r = 0.75).


Preprocedural Planning for Transcatheter Aortic Valve Replacement. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.


Preprocedural Planning for Transcatheter Aortic Valve Replacement. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Acute Trauma to the Knee

Acute Trauma to the Knee. Introduction/Background Acute bone and soft-tissue injuries to the knee may result from low- or high-energy trauma and are commonly seen in emergency departments as well as in outpatient practices [1]. The most common acute knee injuries result from a direct blow, a fall, or a twisting injury [2,3]. The fracture risk increases with age, likely secondary to decreased bone mineral density, increased frequency of blunt injury, and inability to protect the knee during a fall [3]. An estimated 6.6 million knee injuries presented to emergency departments in the United States from 1999 through 2008, for a rate of 2.29 knee injuries per 1,000 population. Prompt and accurate diagnosis facilitates adequate management and may prevent potential complications [1,4].


Acute Trauma to the Knee

Acute Trauma to the Knee. After thorough history and clinical examination, radiographs are usually the initial imaging modality in the evaluation of the acutely injured knee [1]. Adequate clinical examination and appropriate application of the established decision-making rules can reduce the number of radiographic studies in the setting of acute knee injuries with a potential benefit of reducing health care costs and decreasing radiation exposure to the patient [1,5,6]. Treatment options for acute traumatic knee injuries depend on the severity of injury and patient factors and include conservative or surgical management [1].


Acute Trauma to the Knee

Acute Trauma to the Knee. Special Imaging Considerations For the purpose of this document, point-of-care ultrasound (US) is not discussed or listed in the variant tables.


Acute Trauma to the Knee

Acute Trauma to the Knee. For the purposes of distinguishing between CT and CT angiography (CTA), ACR Appropriateness Criteria topics use the definition in the ACR-NASCI-SIR-SPR Practice Parameter for the Performance and Interpretation of Body Computed Tomography Angiography (CTA) [7].


Acute Trauma to the Knee

Acute Trauma to the Knee. 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.


Acute Trauma to the Knee

Acute Trauma to the Knee. 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.


Acute Trauma to the Knee

Acute Trauma to the Knee. Reprint requests to: publications@acr.org


Acute Trauma to the Knee

Acute Trauma to the Knee. Acute Trauma to the Knee Discussion of Procedures by Variant Variant 1: Adult or child 5 years of age or older. Fall or acute twisting trauma to the knee. No focal tenderness, no effusion, able to walk. Initial imaging. CT Knee In the absence of focal tenderness and joint effusion in a patient who is able to walk, CT is not used as the initial imaging study for the evaluation of acute trauma to the knee.


Acute Trauma to the Knee

Acute Trauma to the Knee. MR Arthrography Knee MR arthrography is not routinely used as the initial imaging study for the evaluation of acute trauma to the knee.


Acute Trauma to the Knee

Acute Trauma to the Knee. MRA Knee MR angiography (MRA) is not routinely used as the initial imaging study for the evaluation of acute trauma to the knee.


Acute Trauma to the Knee

Acute Trauma to the Knee. MRI Knee MRI is not routinely used as the initial imaging study for the evaluation of acute trauma to the knee.


Acute Trauma to the Knee

Acute Trauma to the Knee. Radiography Knee With no clinical symptoms in the injured knee, including lack of focal tenderness and joint effusion, and with ability to walk, knee radiographs may be indicated if a patient >55 years old per Ottawa rules or >50 years old or <12 years old per Pittsburgh rule criteria [5, 6, 10]. If the patient is between 5 and 12 years, they fall outside the age range for both the Ottawa and Pittsburgh rules and radiographs may be beneficial despite lack of clinical symptoms.


Acute Trauma to the Knee

Acute Trauma to the Knee. Radiographs are commonly performed in the setting of acute knee injuries but have a low yield for showing fractures. In a retrospective review of 1,967 patients with acute knee injuries by Stiell et al [2], 74.1% of patients had knee radiography, and only 5.2% of these had fractures. Therefore, to avoid a large number of negative radiographic studies, development of the inclusion criteria for obtaining knee radiographs in the setting of the acute trauma was needed.


Acute Trauma to the Knee

Acute Trauma to the Knee. The two most commonly used clinical decision criteria, the Ottawa Knee Rule and the Pittsburgh Decision Rule, can help to decide when to perform radiographs in acute knee trauma [5,6,8].


Acute Trauma to the Knee

Acute Trauma to the Knee. Pittsburgh Decision Rule The Pittsburgh Decision Rule states that patients with acute knee trauma who are <12 years old or >50 years old should have radiographs as well as patients who cannot take 4 weight-bearing steps in the emergency department [5,6].


Acute Trauma to the Knee

Acute Trauma to the Knee. In their prospective study in 178 patients with acute knee trauma with the Ottawa rule criteria applied, Jenny et al [8] found a 35% decrease in the number of radiographic examinations with 100% sensitivity for detecting knee fracture. Similarly, Cheung et al [6] found a 23% reduction of knee radiographs in 90 patients if the Ottawa rule criteria were applied, although they did report 1 patient who had a fracture and did not meet any of the clinical criteria, but this fracture was radiographically occult and visible only by MRI.


Acute Trauma to the Knee

Acute Trauma to the Knee. In their retrospective study on 106 acute knee trauma patients, Konan et al [5] evaluated the role of the Ottawa and Pittsburgh rules to reduce the unnecessary use of radiographs following knee injury. One hundred and one patients (95%) had radiographs of their injured knees. Only 5% of these patients had a fracture on radiographs, all with Ottawa and Pittsburgh knee rules fulfilled. Using the Ottawa rules, 27 radiographic studies (25%) could have been


Acute Trauma to the Knee

Acute Trauma to the Knee. Acute Trauma to the Knee avoided without missing a fracture. Using the Pittsburgh rules, 32 radiographic studies (30%) could have been avoided. In this study, both the Ottawa and Pittsburgh rules showed high sensitivity in detecting knee fractures [5].


Acute Trauma to the Knee

Acute Trauma to the Knee. Other clinical decision criteria were tested. In an emergency department, in a study of 242 patients >17 years with isolated knee injuries sustained 24 hours previously, Weber et al [3] were able to exclude clinically significant fractures in patients >18 years who could walk without limping or if there was a twisting injury to the knee and no joint effusion. These clinical decision rules were effective in detecting knee fractures with 100% sensitivity and with sufficient specificity to eliminate 29% of knee radiographs [3].


Acute Trauma to the Knee

Acute Trauma to the Knee. Bone Scan with SPECT or SPECT/CT Knee Tc-99m bone scan with single-photon emission computed tomography (SPECT)/CT knee is not routinely used as the initial imaging study for the evaluation of acute trauma to the knee.


Acute Trauma to the Knee

Acute Trauma to the Knee. US Knee US is not routinely used as the initial imaging study for the evaluation of acute trauma to the knee.


Acute Trauma to the Knee

Acute Trauma to the Knee. Variant 2: Adult or child 5 years of age or older. Fall or acute twisting trauma to the knee. One or more of the following: focal tenderness, effusion, inability to bear weight. Initial imaging. CT Knee CT is not routinely used as the initial imaging study for the evaluation of acute trauma to the knee.


Acute Trauma to the Knee


Acute Trauma to the Knee

Acute Trauma to the Knee. MRA Knee MRA is not routinely used as the initial imaging study for the evaluation of acute trauma to the knee.


Acute Trauma to the Knee

Acute Trauma to the Knee. Radiography Knee With one or more positive Ottawa rule criteria, including focal tenderness and/or inability to bear weight, radiographs should be the initial imaging modality for the evaluation of acute trauma to the knee [5,6,8].


Acute Trauma to the Knee

Acute Trauma to the Knee. Bone Scan with SPECT or SPECT/CT Knee Tc-99m bone scan with SPECT/CT knee is not routinely used as the initial imaging study for the evaluation of acute trauma to the knee.


Acute Trauma to the Knee

Acute Trauma to the Knee

Acute Trauma to the Knee. Acute Trauma to the Knee


Acute Trauma to the Knee

Acute Trauma to the Knee. Variant 3: Adult or skeletally mature child. Fall or acute twisting trauma to the knee. No fracture seen on radiographs. Suspect occult fracture or internal derangement. Next study. CT Knee CT may be performed as the next imaging study for the evaluation of suspected radiographically occult knee fractures.


Acute Trauma to the Knee

Acute Trauma to the Knee. Several studies reported CT to be superior to knee radiographs in detection and classification of fractures. In a study by Mustonen et al [12], CT showed 100% and radiographs 83% sensitivity in detection of tibial plateau fractures, and CT was superior in further characterization of fracture severity.


Acute Trauma to the Knee

Acute Trauma to the Knee. In the setting of acute knee trauma, Mui et al [13] reported 80% sensitivity and 98% specificity of the CT examination in detecting bony avulsion fractures and a high negative predictive value for excluding ligamentous injuries, but MRI remained necessary for the preoperative detection of meniscal injury.


Acute Trauma to the Knee

Acute Trauma to the Knee. Peltola et al [14] compared dual-energy CT examinations with MRI studies as a reference standard in 18 patients with acute knee trauma and reported dual-energy CT had 79% sensitivity and 100% specificity in detecting anterior cruciate ligament (ACL) ruptures [14].


Acute Trauma to the Knee

Acute Trauma to the Knee. In a study by Heffernan et al [15], 64-channel multidetector CT showed 87.5% to 100% sensitivity and 100% specificity for detection of the ACL tears. As on MRI, secondary signs, such as buckling of the posterior cruciate ligament, were also useful in their diagnosis. In this study, multidetector CT showed a low sensitivity for other soft- tissue injuries at the knee; however, its high specificity indicated that apparent posterior cruciate ligament, meniscal, and collateral ligament tears can reliably be treated as true-positive findings [15].


Acute Trauma to the Knee

Acute Trauma to the Knee. The dual-energy CT virtual noncalcium technique can subtract calcium from cancellous bone, allowing detection [16-18] and possibly grading of the post-traumatic bone marrow contusions [18].


Acute Trauma to the Knee

Acute Trauma to the Knee. However, MRI is superior to CT in detection of bone marrow abnormalities and meniscal and ligamentous injuries and may be subsequently performed as clinically indicated.


Acute Trauma to the Knee

Acute Trauma to the Knee. MR Arthrography Knee With negative radiographs, MR arthrography is not routinely used as the next imaging study for the evaluation of suspected occult knee fractures or internal derangement.


Acute Trauma to the Knee

Acute Trauma to the Knee. MRA Knee With negative radiographs, MRA is not routinely used as the next imaging study for the evaluation of suspected occult knee fractures or internal derangement.


Acute Trauma to the Knee

Acute Trauma to the Knee. MRI Knee MRI has many distinct advantages for the evaluation of the injured knee in the setting of negative radiographs.


Acute Trauma to the Knee

Acute Trauma to the Knee. The majority of patients (93.5%) who present with acute knee injuries in the emergency department sustained soft- tissue injuries rather than osseous injuries [19]. MRI is a proven valuable tool in the treatment decision-making process, allowing earlier surgical intervention by obtaining a more accurate diagnosis [20,21]. Frobell et al [22] reported a low diagnostic benefit of the initial clinical examination in the setting of acute knee trauma with higher- than-suspected incidence of the ACL injuries on MRI. In randomized studies of patients with knee injuries [23,24], MRI findings shortened the diagnostic completion workup, reduced the number of additional diagnostic procedures, and improved quality of life in the first 6 weeks, potentially reducing productivity loss.


Acute Trauma to the Knee

Acute Trauma to the Knee. A retrospective study by Cecava et al [25] showed that knee radiography is a highly specific screening test for internal derangement in patients <40 years old with acute knee injury. In this patient population, knee effusion >10 mm on lateral radiograph should prompt consideration for the knee MRI examination, which can potentially decrease delayed diagnosis, improve patient outcomes, and decrease disability [25].


Acute Trauma to the Knee

Acute Trauma to the Knee. Magee et al [26] reported 96% sensitivity and 97% specificity of 3T MRI in the detection of meniscal tears in correlation with arthroscopy. However, a study by Van Dyck et al [21] showed similar high sensitivities and specificities of routine 3T and 1.5T MRI examinations in the evaluation of meniscal and ACL tears with arthroscopic correlation. Routine 3T MRI protocol did not significantly improve accuracy for evaluating the knee menisci and ACL compared with a similar 1.5T MRI protocol.


Acute Trauma to the Knee

Acute Trauma to the Knee. MRI can diagnose the patterns and severity of bone marrow contusions that frequently have an association with the specific mechanisms of injury and can predict associated soft-tissue injuries [27,28]. In a study by Song et al [28],


Acute Trauma to the Knee

Acute Trauma to the Knee


Acute Trauma to the Knee

Acute Trauma to the Knee. in the setting of the acute noncontact ACL injury, both the presence and the severity of lateral bone contusions were associated with high-grade pivot-shift, concomitant lateral meniscal lesions as well as anterolateral ligament abnormality. Klengel et al [29] found that the apparent diffusion coefficient maps are more sensitive than corresponding proton density-weighted fat-saturated turbo spin-echo MRI sequences for detection of bone marrow lesions after knee trauma and allowed detection of significantly more and larger bone marrow lesions. Additionally, apparent diffusion coefficient map evaluation improved diagnostic performance in regions with insufficient spectral fat saturation, such as the patella. Koster et al [30] showed that the presence of a bone contusion on MRI after acute knee trauma is highly predictive of the development of focal osteoarthritis 1 year after trauma.


Acute Trauma to the Knee

Acute Trauma to the Knee. MRI facilitates diagnosis of the anterolateral ligament injuries that have frequent association with ACL injuries and anterolateral knee instability, of which a minority are associated with Segond fractures [31]. In a study by Kosy et al [32], MRI detected a larger number of anterolateral ligament injuries in association with the ACL injuries within 6 weeks of the acute knee trauma compared with scans performed later, which suggests that some injuries may resolve or become less visible with increased chronicity. MRI is proven helpful in detection and characterization of posterolateral corner injuries, which can be associated with the ACL ruptures and, if missed, may lead to considerable morbidity. In a study by Temponi et al [33], concomitant posterolateral corner injuries and the ACL ruptures were present in 19.7% of patients on MRI studies. Precise location and classification of the ACL tears on the MRI study may help in preoperative planning, in particular with a growing interest in this ligament preservation technique [34].


Acute Trauma to the Knee

Acute Trauma to the Knee. MRI can change management from surgical to conservative in up to 48% of patients presenting with a locked knee, which is usually an indication for arthroscopic procedure [35,36].


Acute Trauma to the Knee

Acute Trauma to the Knee. Bone Scan with SPECT or SPECT/CT Knee Tc-99m bone scan would not be the next best imaging study to evaluate for radiographically occult fractures and/or internal derangement.


Acute Trauma to the Knee

Acute Trauma to the Knee. Tc-99m-methylene diophosphate bone SPECT/CT scan has been suggested as an alternative to MRI in evaluating suspected bone contusions and meniscal and ACL tears in the setting of acute knee trauma. A SPECT study by Even-Sapir et al [37] with arthroscopic and MRI correlation showed promising results in diagnosis of the ACL and meniscal tears and the associated bone contusions in patients with acute knee trauma. Another study by Siegel et al [38] suggested that the degree of radiotracer uptake in the knee, as determined by SPECT, positively correlates with the severity of pathology seen at arthroscopy. However, a more recent SPECT study with arthroscopic correlation by Wertman et al [39] showed a lower sensitivity, specificity, and accuracy than MRI in evaluating meniscal injuries.


Acute Trauma to the Knee

Acute Trauma to the Knee. US Knee US is not used as the next best imaging study to evaluate for radiographically occult fractures and/or internal derangement.


Acute Trauma to the Knee

Acute Trauma to the Knee. US is an excellent and easily performed imaging study in detection of knee joint effusions. However, because of its technical limitations, US may only evaluate the outer bone surface and has a limited role in detection of the occult knee fractures. Therefore, this imaging modality is not routinely used for the evaluation of suspected occult knee fractures but may detect a lipohemarthrosis, which is typically associated with intra-articular fractures. A comparison of US studies with radiography and CT examinations by Bonnefoy et al [40] serving as the reference standard and using a knee lipohemarthrosis as a criterion, yielded a sensitivity of and specificity of 94% for US detection of acute intra-articular fractures. A recent study by Klos et al [41] showed a higher prevalence of Segond avulsions fractures on US studies than previously reported in literature on the MRI or radiography. The lateral femoral condyle impaction injury was the best variable in predicting the presence of a Segond fracture [41].


Acute Trauma to the Knee

Acute Trauma to the Knee. Acute Trauma to the Knee US study by Dai et al including 551 patients from 7 prospective studies revealed pooled sensitivity of 88% and specificity of 90% in diagnosis of meniscal injuries [46].