Osteonecrosis PCAs

Osteonecrosis PCAs. Invasive therapies for early osteonecrosis aim at preventing articular collapse and delaying/preventing the need for joint replacement. Core decompression can be performed in various locations including femoral head, humeral head, and talus. Core decompression can be supplemented with injection of autologous bone marrow cells, vascular fibular grafting, or electric stimulation. However, overall efficacy of core decompression at preventing eventual articular collapse remains controversial [11,19-22]. For late-stage femoral or humeral head osteonecrosis with articular collapse, resurfacing hemiarthroplasty may be needed, whereas total joint arthroplasty is performed in cases of severe secondary osteoarthritis [23]. Femoral head osteonecrosis accounts for 10% of indications for total hip replacements in the United States [24]. For late-stage talar osteonecrosis, talar resection/replacement with arthroplasty or tibiotalar joint fusion may be performed [11].


Osteonecrosis PCAs

Osteonecrosis PCAs. OR Discussion of Procedures by Variant Variant 1: Clinically suspected osteonecrosis. Initial imaging. The body regions covered in this clinical scenario are chest, pelvis, hip, femur, knee, tibia/fibula, ankle, foot, shoulder, humerus, elbow, forearm, wrist, and hand.


Osteonecrosis PCAs

Osteonecrosis PCAs. Radiography Area of Interest Radiography is beneficial as the initial imaging study for clinically suspected osteonecrosis. Although radiographs are less sensitive for detection of early osteonecrosis, they help to exclude other causes of extremity pain such as fracture, primary arthritis, or tumor. Anteroposterior, lateral (frog-leg lateral for hip), and oblique (eg, ankle/knee) views are recommended to exclude subchondral collapse in cases of epiphyseal osteonecrosis [27,28]. In late-stage osteonecrosis, radiography will also show findings of secondary osteoarthritis.


Osteonecrosis PCAs

Osteonecrosis PCAs. Bone Scan Area of Interest In recent years, bone scintigraphy has been replaced by MRI for detection of osteonecrosis because of poor spatial resolution, low specificity, and the inability to quantify size of the necrotic lesion [29]. Single-photon emission CT (SPECT) was shown to improve accuracy of bone scintigraphy in a small group of posttransplant patients [30], but radionucleotide scintigraphy is not commonly performed for detection of osteonecrosis. Early limited data for PET/CT have not been shown to useful in diagnosis of early osteonecrosis [31]. More studies are needed to see if PET/CT may be useful in the detection of multifocal osteonecrosis.


Osteonecrosis PCAs

Osteonecrosis PCAs. CT Area of Interest With IV Contrast There is limited evidence to support the use of CT with IV contrast as the initial imaging study for clinically suspected osteonecrosis.


Osteonecrosis PCAs

Osteonecrosis PCAs. Osteonecrosis CT Area of Interest Without and With IV Contrast There is limited evidence to support the use of CT without and with IV contrast as the initial imaging study for clinically suspected osteonecrosis.


Osteonecrosis PCAs

Osteonecrosis PCAs. CT Area of Interest Without IV Contrast There is limited evidence to support the use of CT without IV contrast as the initial imaging study for clinically suspected osteonecrosis.


Osteonecrosis PCAs

Osteonecrosis PCAs. MRI Area of Interest Without and With IV Contrast There is limited evidence to support the use of MRI without and with IV contrast as the initial imaging study for clinically suspected osteonecrosis.


Osteonecrosis PCAs

Osteonecrosis PCAs. MRI Area of Interest Without IV Contrast There is limited evidence to support the use of MRI without IV contrast as the initial imaging study for clinically suspected osteonecrosis.


Osteonecrosis PCAs

Osteonecrosis PCAs. Variant 2: Clinically suspected osteonecrosis. Normal radiographs or radiographs that show findings suspicious for osteonecrosis. Next imaging study. The body regions covered in this clinical scenario are chest, pelvis, hip, femur, knee, tibia/fibula, ankle, foot, shoulder, humerus, elbow, forearm, wrist, and hand.


Osteonecrosis PCAs

Osteonecrosis PCAs. Bone Scan Area of Interest Because of poor spatial resolution, low specificity, and the inability to quantify the size of the necrotic lesion, bone scintigraphy is not beneficial for characterization of osteonecrosis. SPECT may improve the accuracy of bone scintigraphy [30,32,33] for detection of osteonecrosis, but its use has not been widely accepted. In addition, few studies suggest that bone scan may be used to screen for multifocal osteonecrosis [34,35].


Osteonecrosis PCAs

Osteonecrosis PCAs. CT Area of Interest With IV Contrast There is limited evidence to support the use of CT with IV contrast as the next imaging study for clinically suspected osteonecrosis following radiographs.


Osteonecrosis PCAs

Osteonecrosis PCAs. CT Area of Interest Without and With IV Contrast There is limited evidence to support the use of CT without and with IV contrast as the next imaging study for clinically suspected osteonecrosis following radiographs.


Osteonecrosis PCAs

Osteonecrosis PCAs. CT Area of Interest Without IV Contrast CT is less sensitive than bone scintigraphy and MRI for the detection of early osteonecrosis [36]. Once an insufficiency fracture occurs, CT is superior to MRI in showing location and extent of articular collapse [37,38]. CT also shows osseous details of secondary osteoarthritis well.


Osteonecrosis PCAs

Osteonecrosis PCAs. MRI Area of Interest Without and With IV Contrast MRI with dynamic contrast enhancement has been shown to be useful to differentiate osteonecrosis from transient bone marrow edema syndrome and subchondral insufficiency fracture [39]. Transient bone marrow edema shows subchondral spot of marked hyperperfusion (plasma flow), whereas osteonecrosis shows a rim of high plasma flow surrounding a subchondral area without flow [40]. This rim is thought to represent granulation tissue. Higher slope of enhancement and maximum enhancement in epiphysis was seen in transient bone marrow edema than in subchondral fracture. Osteonecrosis showed overall decreased maximal enhancement [41].


Osteonecrosis PCAs

Osteonecrosis PCAs. MRI Area of Interest Without IV Contrast MRI is the most sensitive and specific imaging modality for the diagnosis of osteonecrosis, with a sensitivity and specificity nearing 100% [24,28,42]. A meta-analysis of 43 studies for early detection of femoral head osteonecrosis reported a sensitivity of 93% and specificity of 91% [43]. MRI allows for characterization of the osteonecrosis including location, volume, and presence of associated bone marrow edema or joint effusion [13,14]. MRI is also important for detecting asymptomatic osteonecrosis in the contralateral hip.


Osteonecrosis PCAs

Osteonecrosis PCAs. Osteonecrosis chondrosarcoma in older adults or chondroblastoma in adolescents). Infarct-associated sarcomas (most commonly malignant fibrous histiocytomas and osteosarcomas) are extremely rare and total up to less than 80 cases in the literature [44,45].


Osteonecrosis PCAs

Osteonecrosis PCAs. Variant 3: Known osteonecrosis with articular collapse by radiographs. Surgery planned. Next imaging study. The body regions covered in this clinical scenario are ankle, elbow, hip, knee, shoulder, and wrist.


Osteonecrosis PCAs

Osteonecrosis PCAs. Bone Scan Area of Interest There is limited evidence to support the use of bone scan for preoperative planning of osteonecrosis.


Osteonecrosis PCAs

Osteonecrosis PCAs. CT Area of Interest With IV Contrast There is limited evidence to support the use of CT with IV contrast for preoperative planning of osteonecrosis.


Osteonecrosis PCAs

Osteonecrosis PCAs. CT Area of Interest Without and With IV Contrast There is limited evidence to support the use of CT without and with IV contrast for preoperative planning of osteonecrosis.


Osteonecrosis PCAs

Osteonecrosis PCAs. CT Area of Interest Without IV Contrast CT is superior to MRI in showing the location and extent of articular collapse [37,38] and, therefore, plays a critical role in surgical planning. Preoperative CT, before total hip arthroplasty, showed that 21% of femoral head osteonecrosis staged as ARCO stage I or II on radiographs to actually be stage III on CT [49]. With developing technologies in 3-D printing, CT also plays an important role. Li et al [50] reported that a 3-D guide plate in core decompression led to decreased surgery time and blood loss.


Osteonecrosis PCAs

Osteonecrosis PCAs. MR Arthrography Area of Interest There is limited evidence to support the use of MR arthrography for preoperative planning of osteonecrosis.


Osteonecrosis PCAs

Osteonecrosis PCAs. MRI Area of Interest Without and With IV Contrast Not surprisingly, the volume of hip synovitis seen on contrast-enhanced MRI was found to be increased after femoral head collapse compared to precollapse [51]. There is limited evidence to support the use of MRI without and with IV contrast for preoperative planning of osteonecrosis.


Osteonecrosis PCAs

Osteonecrosis

Osteonecrosis PCAs. Osteonecrosis


Osteonecrosis PCAs

Osteonecrosis 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.


Osteonecrosis PCAs

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


Chronic Foot Pain

Chronic Foot Pain. Introduction/Background Chronic foot pain is a frequent clinical complaint with approximately 14% to 42% of adults in the United States reporting foot problems, often with significant impact on mobility, difficulty performing daily activities, and increased risk of falling, particularly in older individuals [1,2]. Randomized controlled trials have demonstrated a significant improvement in health-related quality of life with effective treatment of foot pain [3]. Estimating the prevalence of chronic foot pain is challenging, because there is no consensus regarding the definition of chronic pain in the literature. The International Association for the Study of Pain defines chronic pain as any pain persisting past the normal healing time, suggesting 3 months in case of chronic pain of benign causes.


Chronic Foot Pain

Chronic Foot Pain. Women are more commonly affected, and forefoot conditions are more frequent. Persistent pain for more than 6 years has been reported in 51% of women between 70 to 75 years of age [4]. Because of the wide range of causes of chronic foot pain, assessment of these patients with imaging studies in addition to a dedicated clinical examination is often needed [1].


Chronic Foot Pain

Chronic Foot Pain. The guidelines of the American College of Foot and Ankle Surgeons divide heel pain into plantar heel pain, usually related to pathology of the plantar fascia, and posterior heel pain, usually related to pathology of the Achilles tendon, and treatment options vary from nonoperative treatments to surgical procedures [5].


Chronic Foot Pain

Chronic Foot Pain. OR Reprint requests to: publications@acr.org


Chronic Foot Pain

Chronic Foot Pain. Chronic Foot Pain Discussion of Procedures by Variant Variant 1: Chronic foot pain. Unknown etiology. Initial imaging. Bone Scan Foot There is no relevant literature to support the use of nuclear medicine studies as the first imaging study in the evaluation of chronic foot pain.


Chronic Foot Pain

Chronic Foot Pain. CT Foot There is no relevant literature to support the use of CT as the first imaging study in the evaluation of chronic foot pain.


Chronic Foot Pain

Chronic Foot Pain. MRI Foot There is no relevant literature to support the use of MRI as the first imaging study in the evaluation of chronic foot pain.


Chronic Foot Pain

Chronic Foot Pain. Radiography Foot Conventional radiography can be useful to distinguish among different causes of chronic foot pain and is usually the first imaging study in evaluating patients with chronic foot pain.


Chronic Foot Pain

Chronic Foot Pain. The value of radiographs in the diagnosis of tarsal coalitions has been extensively demonstrated. Overall sensitivities range from 80% to 100% and specificities range from 97% to 98% have been reported for radiographs in the diagnosis of calcaneonavicular coalitions. Most calcaneonavicular coalitions are easily detected on lateral and oblique radiographs of the foot and confirmed on sagittal CT or MRI scans [11]. Talocalcaneal or subtalar coalition may be overlooked on standard foot radiographs due to overlapping structures; however, secondary signs on the lateral view could suggest a subtalar coalition. An overall sensitivity of 100% and a specificity of 88% have been found for radiographs in the diagnosis of talocalcaneal coalitions [12]. CT and MRI remain the most reliable methods for diagnosing subtalar coalitions.


Chronic Foot Pain

Chronic Foot Pain. Radiographs are usually performed initially in the clinical setting of a suspected stress fracture. A systematic review by Wright et al [13] reported sensitivities ranging from 12% to 56% and specificities ranging from 88% to 96% for radiographs in the detection of lower-extremity stress fractures.


Chronic Foot Pain

Chronic Foot Pain. Though radiography is typically insensitive in the diagnosis of fasciitis, it should be the initial imaging study in patients with a painful heel. Evidence supports the use of weightbearing radiographs in this instance [5]. The combination of thickened plantar fascia and fat pad abnormalities on radiographs has a sensitivity of 85% and a specificity of 95% for plantar fasciitis [15].


Chronic Foot Pain

Chronic Foot Pain. Variant 2: Persistent posttraumatic foot pain. Radiographs negative or equivocal. Clinical concern includes complex regional pain syndrome type I. Next imaging study. 3-Phase Bone Scan Foot A 3-phase bone scan may be useful in cases of suspected complex regional pain syndrome (CRPS) type I reflex sympathetic dystrophy, and several imaging findings have been described. There is some variation in the literature regarding the diagnostic capabilities of 3-phase bone scan in the diagnosis of CRPS type I. Some authors have found 3-phase bone scan to have higher sensitivity (100%) and negative predictive value (NPV; 100%) when compared to MRI and conventional radiography, and therefore, it may be useful to rule-out disease [16]. A meta-analysis by Cappello et al [17] demonstrated a pooled sensitivity, specificity, NPV, and positive predictive value (PPV) of 78%,


Chronic Foot Pain

Chronic Foot Pain

Chronic Foot Pain. Chronic Foot Pain


Chronic Foot Pain

Chronic Foot Pain. 88%, 88%, and 84%, respectively. There is no relevant literature to support the routine clinical use of nuclear medicine studies in the evaluation of CRPS type II.


Chronic Foot Pain

Chronic Foot Pain. CT Foot There is no relevant literature to support the use of CT in the evaluation of suspected CRPS.


Chronic Foot Pain

Chronic Foot Pain. US Foot A few studies addressing the role of US in the diagnosis of CRPS type I reflex sympathetic dystrophy have been published. There is evidence showing that patients who have CRPS type I affecting the lower extremity have increased power Doppler flow compared with asymptomatic control subjects with a sensitivity of 73% and specificity of 92% [22]. Although there is no relevant literature to support the routine clinical use of US in the diagnosis of CRPS type II, high-resolution US may have a role giving its increasing use in nerve assessment [23].


Chronic Foot Pain

Chronic Foot Pain. MRI Foot MRI is useful in the diagnosis of several conditions affecting the hallucal sesamoid bones, including fractures, acute and chronic stress related changes, and avascular necrosis, and a variety of MRI findings have been described in the literature [12]. Contrast administration is not routinely performed in the assessment of noninfectious and/or


Chronic Foot Pain

Chronic Foot Pain. nontumoral conditions affecting the hallucal sesamoids; however, it could be useful to distinguish between sesamoiditis and avascular necrosis [32,33].


Chronic Foot Pain

Chronic Foot Pain. MRI is widely accepted as the imaging study of choice for diagnosis of plantar plate tears. In a prospective study, Sung et al [40] found high accuracy (96%), sensitivity (95%), specificity (100%), PPV (100%), and NPV (67%) for MRI with surgical correlation. In this study, moderate concordance was found between tear severity on MRI and surgery with greater concordance at higher severity. A meta-analysis showed higher diagnostic accuracy for MRI than US for the detection of plantar plate tears with sensitivity and specificity for MRI of 95% and 54%, respectively [41]. MR arthrography improves visualization of pericapsular structures when compared to conventional MRI and therefore is useful in the diagnosis and characterization of plantar plate tears and abnormalities of related structures [42,43].


Chronic Foot Pain

Chronic Foot Pain. US Foot There is limited information available in the literature regarding the use of US in the diagnosis of sesamoiditis. US has been shown to be useful in diagnosing tears of the sesamoid phalangeal ligament in the setting of turf toe [46].


Chronic Foot Pain

Chronic Foot Pain. MRI is generally better, but US is also useful in the diagnosis of plantar plate tears. In a cadaveric study, an accuracy, sensitivity, and specificity of 79%, 78%, and 80%, respectively, were found for US [48]. With MRI as the reference standard, Gregg et al [49] showed a sensitivity, specificity, PPV, NPV, and accuracy of 91%, 44%, 93%, 35%, and 85%, respectively, for US in the detection of metatarsophalangeal plantar plate tears in symptomatic subjects. A meta-analysis showed higher diagnostic accuracy for MRI than US for the detection of plantar plate tears. In this meta-analysis the sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were 93%, 33%, 1.2, and 0.35, respectively, for US [41].


Chronic Foot Pain

Chronic Foot Pain. Variant 4: Chronic plantar heel pain. Radiographs negative or equivocal. Clinical concern includes plantar fasciitis or plantar fascia tear. Next imaging study. Bone Scan Foot with SPECT or SPECT/CT SPECT/CT has been found to be of use when investigating heel pain with increased specificity when compared to bone scintigraphy alone, because of the improved anatomic localization of metabolic activity. Despite the anatomic and functional advantages of SPECT/CT, MRI and high-frequency US remain the most frequently used imaging modalities in patients with heel pain [50]. A characteristic pattern of abnormal uptake on 3-phase bone scintigraphy has been proven helpful to differentiate plantar fasciitis from calcaneal stress or avulsion fractures [51]. There is no relevant literature to support the routine use of nuclear medicine studies to diagnose plantar fascial tears.


Chronic Foot Pain

Chronic Foot Pain. CT Foot There is no relevant literature to support the routine use of CT in the evaluation of a patient with clinical suspicion of pathology of the plantar fascia.


Chronic Foot Pain

Chronic Foot Pain. MRI Foot MRI allows accurate characterization of the plantar fascia and adjacent soft-tissues and bones, and several imaging findings have been described in patients with plantar fasciitis and partial or complete tears of the plantar fascia on MRI [52]. Given that, some of the findings in patients with plantar fasciitis are nonspecific; these findings can also be seen in asymptomatic patients. MRI should always be correlated with clinical symptoms to avoid overcalling plantar fasciitis. Although no significant differences have been found in plantar fascia thickness on US and MRI, MRI is currently considered the most sensitive imaging study in the diagnosis of plantar fasciitis [53]. There is no relevant literature supporting the routine use of contrast in the diagnosis of plantar fasciitis or tears.


Chronic Foot Pain

Chronic Foot Pain. US Foot US has shown good sensitivity (80%) and specificity (88%) in the diagnosis of plantar fasciitis when compared to MRI [54]. A diagnostic accuracy of 69% for abnormal focal echogenicity within the plantar fascia, 60% for edema around the plantar fascia, 78% for perifascial edema, 69% for rupture of the plantar fascia, and 56% for an associated calcaneal spur have been found for US, using MRI as the reference standard [55]. Kapoor et al [56] showed higher sensitivity and specificity of US elastography when compared to US in the detection of plantar fasciitis (95% and 100% versus 66% and 75%, respectively), using MRI as the reference standard. US has been shown to be useful in the diagnosis of complete and partial tears of the plantar fascia [57]. Some authors regard US to be superior to MRI in differentiating true fiber interruption and tearing of the plantar fascia from edema [58].


Chronic Foot Pain

Chronic Foot Pain. Variant 5: Nonradiating chronic midfoot pain of suspected osseous origin. Radiographs negative or equivocal. Clinical concern includes occult fracture, or painful accessory ossicles. Next imaging study. Bone Scan Foot Bone scintigraphy is a sensitive but not specific technique to detect occult fractures because of its capability to detect increased osteoblastic activity. Although bone scans may reveal focal uptake at the site of a radiographically occult fracture, given the anatomical complexity of the foot particularly the midfoot, precise localization may be limited [59]. SPECT/CT may improve the diagnosis of patients with suspected fractures because of the more precise anatomical localization [60].


Chronic Foot Pain

Chronic Foot Pain. Symptomatic accessory navicular bones were initially studied with Tc-99m-MDP bone scans and were reported to show increased radiotracer uptake at the synchondrosis, apparently due to the chronic stress reaction [61]. A negative bone scan can exclude the presence of a symptomatic accessory ossicle, but positive findings lack specificity [62]. Isotope bone scans, when combined with CT, may be positive in cases of painful accessory ossicles but remain relatively insensitive for some soft-tissue pathology [63].


Chronic Foot Pain

Chronic Foot Pain. CT Foot CT is useful for the detection of radiographically occult fractures. Almeida et al [64] reported visualization of Chopart fractures on CT and/or MRI in one-third of cases initially not diagnosed on radiographs. CT also has utility in the diagnosis of occult fractures involving the subtalar joint as demonstrated in the study by Choi et al [65]. CT is a primary imaging technique in patients with high-energy polytrauma and complex fractures, because radiographs have only poor to moderate sensitivity in this clinical setting [66]. More recently, dual-energy CT has been reported as a useful technique in the detection of bone marrow edema, with excellent performance in the appendicular skeleton, with a sensitivity of 98% and specificity of 93% [67]. This could potentially aid in the detection of radiographically occult fractures.


Chronic Foot Pain

Chronic Foot Pain. CT may be useful to confirm the presence of an accessory ossicle, os fragmentation or fracture, intra-articular bodies, or osteochondral abnormalities. In contrast to conventional radiographs, CT offers multiplanar capability allowing detailed characterization of the ossicle and the synchondrosis. Assessment of associated soft-tissue pathology or bone marrow edema on CT is limited when compared to MRI [68].


Chronic Foot Pain

Chronic Foot Pain. There is no relevant literature supporting the routine use of contrast-enhanced CT images in the diagnosis of occult fractures or symptomatic accessory ossicles, besides a possible use of CT arthrography to demonstrate disruption of the synchondrosis in the setting of os trigonum syndrome [69].


Chronic Foot Pain

Chronic Foot Pain

Chronic Foot Pain. Chronic Foot Pain


Chronic Foot Pain

Chronic Foot Pain. MRI Foot MRI allows the visualization of bone marrow edema patterns, which improves the detection of fractures in cases of negative or inconclusive radiographs [70]. The utility of MRI in the detection of radiographically occult Chopart fractures has been demonstrated by Almeida et al [64]. Baker et al [71] analyzed 31 occult fractures involving the ankle and foot in hockey players, finding five occult fractures in the foot, all of which involved the navicular bone. Pierre-Jerome et al [72] found 79% of cuboid fractures in the diabetic population that were radiographically occult using MRI. MRI is also useful in the detection of occult fractures involving the fifth metatarsal bone (Jones fracture) and the subtalar joint [65,73]. There is no evidence in the literature supporting the routine use of contrast in the diagnosis of occult fractures.


Chronic Foot Pain

Chronic Foot Pain. MRI has replaced bone scans in the evaluation of symptomatic accessory ossicles. MRI allows optimal visualization of the bone marrow within the ossicle and visualization of the synchondrosis. Accessory ossicles may also be associated with tendon pathology, which is also well assessed on MRI [74]. MRI allows clear demonstration of the findings often associated with posterior ankle impingement syndrome [75]. Contrast administration is not routinely performed when assessing symptomatic accessory ossicles on MRI; however, contrast within a disrupted synchondrosis may be demonstrated on MR arthrography studies [69].


Chronic Foot Pain

Chronic Foot Pain. US Foot Although not routinely performed, previous studies have demonstrated the role of US in the detection of occult foot fractures. On US, these can be seen as cortical irregularities and are frequently associated with soft-tissue injury in the acute or subacute setting. Wang et al [76] demonstrated 24 cases of radiographically occult ankle and foot fractures in 268 patients. Of these, foot fractures were found most frequently in the calcaneus and metatarsals, and less frequently in the navicular, cuboid, and cuneiform bones.


Chronic Foot Pain

Chronic Foot Pain. On US, several findings have been reported in cases of painful accessory ossicles, including patients with posterior ankle impingement syndrome; however, optimal characterization of the synchondrosis is difficult on US [62]. High- resolution US offers some advantages over other imaging modalities because it allows dynamic exploration of the foot with further assessment of stability of the synchondrosis and tendon tears when present as well as direct clinical correlation and comparative evaluation with the asymptomatic foot [77]. Power Doppler US has proven useful in identifying increased blood supply in the setting of ankle impingement [78,79].


Chronic Foot Pain

Chronic Foot Pain. 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.


Chronic Foot Pain

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


Chronic Foot Pain

Chronic Foot Pain. Appropriateness Category Names and Definitions Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate


Second and Third Trimester Vaginal Bleeding. 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.


Second and Third Trimester Vaginal Bleeding. Reprint requests to: publications@acr.org


Second and Third Trimester Vaginal Bleeding. Second and Third Trimester Vaginal Bleeding


Second and Third Trimester Vaginal Bleeding. In the setting of premature rupture of membranes, there is a paucity of evidence on whether the introduction of the transvaginal probe may be associated with an increased risk of chorioamnionitis. Carlan et al [19] in a randomized trial of 92 patients did not find any associated increased risk. Nonetheless, caution should be applied in this setting.


Second and Third Trimester Vaginal Bleeding. Special Imaging Considerations Transrectal US is a useful technique and is generally well tolerated when transvaginal and transperineal US are either unsuccessful or declined [20,21].


Second and Third Trimester Vaginal Bleeding. OR Discussion of Procedures by Variant Variant 1: Second and third trimester vaginal bleeding. Painless bleeding. Initial imaging. US Cervix Transperineal The literature is sparse with regard to defined indications for the use of transperineal US or translabial US among those with painless vaginal bleeding. In current US use, if transabdominal US demonstrates an open cervix with bulging membranes or if the history and physical examination suggests ruptured membranes, then transperineal US might be considered. If transabdominal US is inconclusive and transvaginal US is declined by the patient, transperineal US or transrectal US may be useful for making an accurate diagnosis.


Second and Third Trimester Vaginal Bleeding. US Duplex Doppler Pelvis Although Doppler velocimetry US is an adjunct to any of the other procedures for evaluation of painless vaginal bleeding, it can be invaluable for identification of pathologic entities such as vasa previa [22]. Vessels overlying the internal cervical os can be subtle and challenging to diagnose without optimal imaging conditions, and the use of color and spectral Doppler velocimetry US can be essential for making accurate diagnoses and distinguishing fetal from maternal vessels especially with the presence of fetal arterial vessels.


Second and Third Trimester Vaginal Bleeding. US Pregnant Uterus Transabdominal The primary goal of transabdominal US in the setting of painless bleeding is to exclude pathologic etiologies for the bleeding. Impending miscarriage or early labor can typically be excluded via history and physical examination. The most common etiologies for painless vaginal bleeding would be placenta previa, and, less commonly, vasa previa [23]. Transabdominal US is the preferred initial imaging procedure as a screening tool for placenta previa [24]. This evaluation should include visualization of the placenta, the inferior placental margin, the placental umbilical cord insertion, and the cervix from the external os to the internal os. Any vessels overlying the internal cervical os should be specifically excluded. Transabdominal visualization of the lower uterine segment and cervix can be suboptimal because of inadequate urine in the bladder of from shadowing from the maternal symphysis pubis.


Second and Third Trimester Vaginal Bleeding. US Cervix Transperineal The literature is sparse in regard to defined indications for the use of transperineal US among those with painful vaginal bleeding. In current US use, if transabdominal US demonstrates an open cervix with bulging membranes or if the history and physical examination suggests ruptured membranes, then transperineal US might be considered. If transabdominal US is inconclusive and transvaginal US is declined by the patient, transperineal US may be useful for making an accurate diagnosis.


Second and Third Trimester Vaginal Bleeding. US Duplex Doppler Pelvis Although Doppler velocimetry US is an adjunct to any of the other procedures for evaluation of painful vaginal bleeding, it can be invaluable for identification of pathologic entities like placental abruption. An acute clot within the uterus can have an echogenicity similar to that of the placenta; therefore, a placental abruption can be difficult to diagnose, especially prior to organization of the clot [5]. Identification of an area of interest contiguous with the placenta but with no blood flow as documented using color or power Doppler US could suggest the presence of an acute clot as seen with placental abruption. Although color or power Doppler US appears to be helpful with the diagnosis of placental abruption, spectral Doppler US of the fetal arterial vessels appears to be less helpful [27].


Second and Third Trimester Vaginal Bleeding. US Pregnant Uterus Transabdominal Transabdominal US assessment is the preferred initial procedure for this evaluation and for assessment of the placenta. As in those with painless vaginal bleeding, an evaluation for placenta previa and vasa previa is indicated. The placenta is also comprehensively evaluated to assess its location, the presence of any clot as seen with placental separation in placental abruption, the placental location, and the presence of any vessels overlying the internal cervical os [23,24]. Although US is not sensitive for the diagnosis of placental abruption, the identification of a placental abruption is associated with worse perinatal outcomes [28]. The uterus should be evaluated for signs of uterine rupture, especially among those with a history of prior cesarean delivery. Although uterine rupture is typically a clinical diagnosis, imaging might be helpful in certain cases. Any disruption of the myometrium would suggest a uterine rupture. A threshold of 2.5-mm thickness of the lower uterine segment has been shown to be predictive of uterine dehiscence [29].


Second and Third Trimester Vaginal Bleeding. US Pregnant Uterus Transvaginal Transvaginal US is frequently necessary for evaluation of painful vaginal bleeding especially if transabdominal US is inconclusive or inadequate. As with transabdominal US, the evaluation should include visualization of the placenta if identifiable, the inferior placental margin, the presence of any clot within the uterus, the continuity of the myometrium, the cervix from the external os to the internal os, and the identification of any vessels overlying the internal cervical os. Although a transvaginally identified short cervix is well known to be related to preterm delivery, associated vaginal bleeding significantly increases the risk of preterm delivery [30]. Evaluation of the lower uterine segment, the uterine isthmus [31], during transvaginal US can predict bleeding during pregnancy and delivery among those with placenta previa [32].


Second and Third Trimester Vaginal Bleeding. Variant 3: Second and third trimester vaginal bleeding. Suspicion of or known placental previa, low-lying placental, or vasa previa. Initial imaging. US Cervix Transperineal To our knowledge, there is currently a paucity of literature to support the use of transperineal US for the initial evaluation of placenta previa, low-lying placenta, or vasa previa [33].


Second and Third Trimester Vaginal Bleeding. US Duplex Doppler Pelvis Although Doppler velocimetry US is an adjunct to transabdominal US and transvaginal US for evaluation of known or suspected placenta previa, low-lying placenta, or vasa previa, it can be invaluable for identification of pathologic


Second and Third Trimester Vaginal Bleeding. Second and Third Trimester Vaginal Bleeding entities like vasa previa. Vessels overlying the internal cervical os can be subtle and challenging to diagnose without optimal imaging conditions, and the use of Doppler velocimetry US can be essential for making this diagnosis [7,34]. Furthermore, spectral Doppler may play an important role in distinguishing fetal arterial vessels from maternal vessels when overlying the internal cervical os.


Second and Third Trimester Vaginal Bleeding. US Pregnant Uterus Transvaginal Transvaginal US is frequently necessary for evaluation of known or suspected placenta previa, low-lying placenta, or vasa previa, especially if transabdominal US is inconclusive or inadequately demonstrates the internal cervical os and inferior placental margin. As with transabdominal US, the evaluation should include visualization of the placenta if identifiable, the inferior placental margin, the cervix from the external os to the internal os, and the identification of any vessels overlying the internal cervical os. Among those with placenta previa, a shortening cervix is associated with an increased risk for emergency cesarean delivery [43], and a transvaginal cervical length of <35 mm was associated with an increased risk of preterm cesarean delivery due to massive hemorrhage [44]. As placenta previa and low-lying placenta can resolve over gestation, vasa previa has been reported to resolve in 5.8% to 23.8% of cases [45,46].


Second and Third Trimester Vaginal Bleeding. 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.


Second and Third Trimester Vaginal Bleeding. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Introduction/Background A thorough neurologic and ophthalmologic examination can often accurately localize a defect along the visual pathway. Combined with factors such as the age of the patient, the time-course for onset, degree of visual loss at presentation, the presence of eye pain, and visible exophthalmos or enophthalmos determine if imaging is needed, the choice of imaging modality, coverage to include the orbit, anterior skull base and/ or brain, and contrast phase [1].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Disease along the visual pathway may be intrinsically related to the globe, optic nerve, optic chiasm, optic tracts, optic radiations, or primary visual cortex or related to extrinsic mass effect from adjacent pathology upon these structures. Primary diseases of the orbit may present with proptosis, visual disturbance, and/or ophthalmoplegia. These signs and symptoms may occur alone or in combination and may be accompanied by pain or other features including vascular congestion or erythema. The differential diagnosis in adults and subsequent appropriate imaging tests are dependent on the pattern and whether visual loss is monocular or binocular [2].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Imaging analysis of orbital diseases is facilitated by a compartmental approach that establishes a differential diagnosis on the basis of lesion location along the visual pathway [5]. Computed tomography (CT) and magnetic resonance imaging (MRI) are often complementary when assessing visual loss [6,7]. The inherent contrast provided by orbital fat allows for excellent anatomic definition with either technique. Ultrasound (US) and fluorescein angiography are also important diagnostic tools; however, these unique procedures are most often performed by the ophthalmologist and are beyond the scope of this article.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Discussion of Procedures by Variant Variant 1: Traumatic visual defect. Suspect orbital injury. Initial imaging. Patients with traumatic orbital injury may have injuries that are isolated to the orbit or have intracranial manifestations, depending on the mechanism and severity of injury. In the United States, orbital trauma accounts for approximately 3% of visits to the emergency department [8]. Orbital injury should be suspected if periorbital soft-tissue swelling, hyphema, vision loss, or extraocular restriction is present.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. 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.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. *The views expressed in this manuscript are those of the author and do not reflect the official policy of the Department of Army/Navy/Air Force,


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Department of Defense, or United States Government. Reprint requests to: publications@acr.org


Orbits Vision and Visual Loss

Orbits, Vision and Visual Loss

Orbits Vision and Visual Loss. Orbits, Vision and Visual Loss


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Radiography Orbital or skull radiographs are insufficient to detect pathology in patients presenting with trauma and have primarily been supplanted by CT.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Variant 2: Nontraumatic orbital asymmetry, exophthalmos, or enophthalmos. Initial imaging. Orbital asymmetry is a broad term that refers to the external appearance of the orbit. This asymmetry may be related to globe position, with one eye perceived or measured as more proptotic compared to the other, or one eye perceived as sunken or retracted compared to the other. Normal range measurements vary and are dependent on the race of the individual [18,19].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Bilateral exophthalmos may indicate an underlying systemic or diffuse condition, such as thyroid eye disease. Unilateral or asymmetric proptosis is concerning for an underlying mass or pathologic process intrinsic to the globe, optic nerve, extraocular muscles, lacrimal glands, or adjacent soft-tissue structures, posterior to the orbit, within the adjacent skull base or cavernous sinus. Vascular malformations may result in proptosis in adults, and occur anywhere within the orbit. Carotid-cavernous fistula (CCF) may present with proptosis with orbital congestion and chemosis in the setting of an anterior-draining CCF or diplopia and pain in the posterior-draining CCFs [20].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Enophthalmos, or posterior displacement of the globe, may be caused by a development condition resulting in an absent globe (anophthalmia) or small globe (microphthalmia) by traumatic injury to the bony orbit, silent sinus syndrome, processes the extraocular muscles, or by a desmoplastic neoplastic/inflammatory process [9,21-24].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. If the asymmetry is associated with a white pupillary reflex (leukocoria), the primary concern is an abnormality localized to the globe. Although leukocoria is a term often used in the pediatric population, this term is not limited to children. Any condition that prevents passage of light through the globe may cause leukocoria, including tumors, developmental processes, and infection [25,26]. Initial evaluation in a patient with leukocoria consists of


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Patients with disconjugate gaze between the two eyes may also present with orbital asymmetry. These patients may present with diplopia or double vision and is further discussed in Variant 8.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. MRI In patients with proptosis or if a mass lesion is suspected within the globe, optic nerve, within the adjacent orbital soft tissues, or within the adjacent skull base, an MRI of the orbits without and with contrast is the optimal imaging modality used to localize and characterize the primary lesion [27-30].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. MRI has improved soft tissue characterization, and diffusion-weighted imaging may be particularly useful in situations where lymphoma is a consideration [31]. Although contrast is preferred, an MRI of the orbits without contrast may be appropriate if contrast cannot be given. An MRI of the head without and with contrast may also be added to assess the extent of intracranial disease and to evaluate for distant intracranial metastasis. A CT of the orbits is complementary in assessing orbital lesion characteristics and the extent of disease in this clinical presentation [7].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Orbital inflammatory conditions including thyroid eye disease, IgG4-related disease, and idiopathic orbital inflammatory syndrome may all present with unilateral or bilateral proptosis as a clinical manifestation. Like other orbital conditions, patients with these conditions may be imaged with CT or MRI, and these modalities provide overlapping information related to disease extent. Currently, there is no consensus on the optimal imaging modality to assess patients presenting with idiopathic orbital inflammatory disease or IgG4-related orbital disease. If intracranial extension is suspected, an MRI of the head is the preferred next step in assessment.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. CT For assessment of orbital asymmetry, CT of the orbits with contrast is complementary to MRI [7]. In the setting of thyroid eye disease, CT provides useful information about orbital, muscle, and fat volumes and osseous anatomy, particularly when orbital decompression is a surgical consideration [7,32-34]. Orbital inflammatory conditions including thyroid eye disease, IgG4-related disease, and idiopathic orbital inflammatory disease may all present with unilateral or bilateral proptosis as a clinical manifestation. Like other orbital conditions, patients with these conditions may be imaged with CT or MRI, and these modalities provide overlapping information related to disease extent. Currently there is no consensus on the optimal imaging modality to assess patients presenting with idiopathic orbital inflammatory disease or IgG4-related orbital disease. CT of the head with contrast may also be added to assess the extent of intracranial disease, particularly if MRI is not available or contraindicated. Precontrast and postcontrast imaging is typically not necessary in evaluating these patients as the precontrast images do not add significant diagnostic information in this scenario.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. CTA, MRA, Arteriography Vascular structures in and around the orbit may be imaged with CTA, MRA, or catheter-based DSA. Similar to conventional CT and MRI, CTA and MRA may provide complementary information. CTA is performed following the injection of intravascular iodinated contrast and is typically imaged in the arterial phase. MRA can be performed without contrast using the time-of-flight technique or with contrast with an added benefit of producing time-resolved information.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Angiographic imaging is helpful in evaluating adults with a suspected vascular anomaly to define high- or low- flow vascular components, vascular supply, and drainage. This may be achieved with MRA, CTA, or DSA. MRA is the preferred method for evaluating these lesions because of the improved soft-tissue lesion characterization with this modality, superior anatomic localization, and the ability to perform time-resolved techniques. If the differential consideration is vascular mass versus malformation, flow characterization may be achieved with time- resolved MRA [35,36].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. If a CCF is suspected, noninvasive vascular imaging with MRA and CTA are often indicated for diagnosis confirmation and pretreatment planning. When MRA or CTA is combined with anatomic MRI or CT, the secondary findings associated with CCF, including proptosis, vascular congestion within the orbit, extraocular muscle enlargement, and enlarged superior ophthalmic veins, can be easily identified. DSA is performed for more detailed assessment and intervention in patients with confirmed CCFs or in patients with a high index of suspicion for CCFs not confirmed on noninvasive imaging [37]. Although DSA is considered the gold standard for imaging


Orbits Vision and Visual Loss

Orbits, Vision and Visual Loss


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. evaluation and treatment and may be appropriate in the acute assessment of acute visual loss related to suspected CCF, it is relatively invasive and carries its own procedural risks and is typically not performed as the initial test. In addition, DSA lacks in the ability to provide regional soft-tissue information seen with cross-sectional imaging that may assist in making the diagnosis. In a retrospective comparative analysis between CTA, MRA, and DSA, CTA was shown to be as useful as DSA for CCF detection in a cohort of 53 patients [20]. MRA was slightly less successful but still determined as good by demonstrating CCFs in approximately 80% of cases [20].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Radiography Orbital or skull radiographs are insufficient to detect pathology in patients presenting with proptosis and have primarily been supplanted by CT.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Variant 3: Suspected orbital cellulitis, uveitis, or scleritis. Initial imaging. Patients presenting with symptoms and signs of orbital cellulitis (postseptal cellulitis) are often referred for imaging to assess for complications including intraorbital abscess, intracranial involvement, and vascular compromise. The source of this infection is often from the adjacent paranasal sinuses and may be viral, bacterial, or fungal [38].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Idiopathic other (IOIS), inflammatory/granulomatous processes are potential clinical and imaging mimics for orbital cellulitis. IOIS, previously known as orbital pseudotumor, may present with signs and symptoms that mimic infection and is a diagnosis of exclusion. IgG4-related orbital disease is a relatively recently described inflammatory condition that may account for a significant percentage of patients that have been previously described as idiopathic [39-41]. Manifestations include eyelid or periocular swelling, lacrimal gland enlargement, extraocular muscle involvement, intraorbital mass, proptosis, and cranial nerve V involvement.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. CT CT of the orbits with contrast is often the initial imaging modality in the emergent setting for suspected infection [2,7,42,43]. CT is superior to MRI for foreign body assessment, calcification detection, and osseous evaluation [43]. CT can be used in conjunction with the Chandler criteria to evaluate for the presence of bone erosion and subperiosteal abscess, which may require surgical intervention [38,44-46]. Imaging findings may show bone erosion on CT, opacification of a neighboring infected sinus, and/or intraorbital extension of inflammatory disease [47]. In patients who cannot receive contrast, a noncontrast orbit CT may still add useful information. Precontrast and postcontrast imaging is typically not necessary in evaluating these patients as the precontrast images do not add significant diagnostic information in this scenario.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Currently there is no consensus on the optimal imaging modality to assess patients presenting with IOIS or IgG4- related orbital disease. Orbital CT and MRI are often complementary in their roles. Signs of inflammation may be detected with CT or MRI, which show intraconal or extraconal soft-tissue lesions that are diffuse or localized and commonly involve the orbital apex [43,48]. These findings may be initially seen on CT and subsequently further evaluated with MRI for improved soft-tissue characterization.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. MRI Orbital MRI is complementary to CT in evaluating intraorbital spread of infection. An MRI of the orbits without and with contrast should be considered if a more detailed assessment of intraorbital spread of infection is clinically warranted. In patients with suspected intracranial extension or complications, an MRI of the brain with high-resolution images to include the cavernous sinuses [2,42,43,46,47] provides greater soft-tissue resolution than CT. A high index of suspicion and low threshold for MRI is needed if invasive fungal infection is of concern in an immunocompromised patient [42,46,47] because of the morbidity of the disease. Although contrast is preferred, in patients who cannot receive contrast, a noncontrast orbital MRI may provide useful information.


Orbits Vision and Visual Loss

Orbits, Vision and Visual Loss

Orbits Vision and Visual Loss. Orbits, Vision and Visual Loss


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. CTA, MRA, Arteriography CTA or MRA may be added to routine CT or MRI scans if there is a suspicion for vascular invasion including cavernous sinus thrombosis, particularly in the setting of fungal disease. MRA may be performed without and/or with contrast. In the setting of cavernous sinus thrombosis, a contrast-enhanced MRA may provide additional information not provided by a traditional noncontrast MRA examination. There is a limited role for DSA in evaluating patients with orbital infection.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Radiography Orbital radiographs are insufficient to detect orbital cellulitis. Radiographs have largely been supplanted by CT when imaging is necessary [49].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Variant 4: Suspected optic neuritis. Initial imaging. Optic neuritis is defined as an acute inflammatory condition of the optic nerve, and can be unilateral or bilateral. It often presents with painful visual loss [50] but can also be painless. The primary differential consideration includes multiple other optica, infectious/granulomatous conditions. Although optic neuritis can be idiopathic, it is often seen as the initial manifestation of multiple sclerosis.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. MRI In patients presenting with a clinical suspicion for optic neuritis, both MRI of the orbits and MRI of the head without and with contrast are the primary imaging studies for initial assessment. This serves two primary purposes. The first purpose is to evaluate for abnormal enhancement and signal changes within the optic nerve, and the second is to evaluate the brain for associated intracranial demyelinating lesions, as the latter is a strong predictor of the subsequent development of multiple sclerosis [50-52]. MRI is incorporated into the revised McDonald criteria and MAGNIMS consensus guidelines [53] for diagnosing multiple sclerosis, which is characterized by establishing dissemination of lesions in space and time [51]. Neuromyelitis optica is a demyelinating condition that typically affects the optic nerves and spinal cord and is best assessed with MRI [54]. Serum and cerebrospinal fluid laboratory tests may also be useful in differentiating between these two entities [51,55].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. CT Although an imaging test of the brain may be indicated prior to lumbar puncture in patients with optic disc edema to exclude a space occupying mass, CT imaging of the head is typically not indicated specifically for the evaluation of a patient with optic neuritis.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. CTA, MRA, Arteriography Angiography is not routinely used in the initial evaluation of optic neuritis.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Radiography Orbital or skull radiographs are insufficient to detect pathology in patients presenting with clinical concern for vision loss.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. MRI MRI is not routinely used in the evaluation of non-neoplastic ocular processes. In patients with glaucoma, a primary cause of irreversible blindness, there has been interest in applying advanced MRI techniques to earlier detection of this disease process; however, additional research is needed to validate the utility of these advanced techniques [56].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Orbits, Vision and Visual Loss CT CT is not routinely used in the evaluation of nontraumatic, noninfectious, or non-neoplastic ocular processes.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. CTA, MRA, Arteriography CTA, MRA, and DSA are not first-line tests in this scenario.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Radiography Orbital or skull radiographs are insufficient to detect pathology in patients presenting with vision loss.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Variant 6: Visual loss. Intraocular mass, optic nerve, or pre-chiasm symptoms. Initial imaging. Monocular visual loss may be due to an intraocular mass, such as melanoma [57], or may involve the intraorbital, intracanalicular, or pre-chiasm segments of the optic nerve. This includes lesions intrinsic to the nerve, such as an optic nerve glioma, or extrinsic to the nerve resulting in mass effect, such as an optic nerve sheath meningioma. The differential diagnosis varies based on the age of the patient.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. MRI MRI provides excellent soft-tissue resolution of structures within the orbit, including the globe, muscles, tendons, nerves, and vascular structures. MRI of the orbits without and with contrast is the preferred modality in evaluating soft-tissue pathology within and around the orbit, particularly in mass characterization, optic nerve pathology, and assessing disease within the globe and orbit [1,7,58]. If contrast cannot be given, a noncontrast orbit MR may still provide useful information. If there is a significant intracranial component, additional MRI of the brain without and with contrast may be indicated to evaluate for intracranial spread of disease.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. CT CT is superior to MRI for foreign body assessment, calcification detection, and osseous evaluation [43]. Orbital CT is complementary to MRI in evaluating patients with ocular, orbital, and skull base neoplasms. In patients presenting with clinical suspicion for an intraorbital mass lesion, orbital CT with contrast may be complementary to MRI in providing additional information about adjacent bone involvement, including bone erosion, sclerosis, or periosteal reaction that may not be readily seen with MRI [2,7].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. If contrast cannot be given, a noncontrast orbit CT may still add useful information. CT imaging of the head with contrast may also be appropriate if more extensive skull or skull-base involvement is suspected. Precontrast and postcontrast orbital imaging is typically not necessary in evaluating these patients as the precontrast images do not add significant diagnostic information in this scenario.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. CTA, MRA, Arteriography CTA or MRA are complementary and may be added to routine CT or MRI scans if there is a suspicion for an intraorbital vascular lesion [35,36]. MRA without and with contrast may be preferred over CTA if time-resolved information is needed in lesion characterization. DSA is not a first-line test in this scenario.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Radiography Orbital or skull radiographs are insufficient to detect pathology in patients presenting with monocular vision loss.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Variant 7: Nonischemic visual loss. Chiasm or post-chiasm symptoms. Initial imaging. If a patient presents with a junctional scotoma or bitemporal hemianopia, a parasellar lesion is suspected, with mass effect on the optic chiasm affecting the crossing temporal fibers. Lesions may arise from the pituitary gland, hypothalamus, or adjacent dura, and accompanying endocrine abnormalities may also be present.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Slowly progressive binocular visual defect findings suggest an intracranial or skull-base abnormality, including primary neoplasms and metastatic lesions. Mass effect from other intracranial pathology, including abscess, multiple sclerosis, or vascular lesions such as arteriovenous malformations and cerebral aneurysms, may also present with a similar visual field deficit.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Orbits, Vision and Visual Loss MRI Patients with a junctional scotoma or bitemporal visual defect are best assessed with an MRI of the brain without and with contrast, which includes the thin-slice profile needed to evaluate the pituitary gland and any suprasellar mass effect [43]. Detailed assessment of the optic chiasm and its relationship to an underlying mass are easily seen with an MRI of the brain without and with contrast. If contrast cannot be given, an MRI of the brain without contrast may be appropriate.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Patients presenting with a homonymous hemianopia or quadrantanopia defect are best assessed with an MRI of the brain without and with contrast [2,7,59-61]. Because the defect is most likely in a post-chiasm location, additional smaller field-of-view images of the orbit are typically not necessary.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. CT For lesion characterization in and around the sella, CT of the head may be complementary to MRI and add additional information on the characteristics of the lesion, including the presence of calcification such as in a craniopharyngioma [7,59,62]. In patients with post-chiasm symptoms, an MRI of the brain is typically preferred over CT, particularly in a subacute, slowly progressive presentation. In the acute setting, a noncontrast head CT is reasonable for initial imaging. If a patient is unable or unwilling to have MRI, then a CT of the head without and with contrast may be an appropriate alternative.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. If a mass such as a meningioma is identified in close proximity to the sagittal sinus, additional MRV or CTV imaging may be indicated to assess the integrity of the dural venous sinus. Postcontrast MRV and CTV are complementary in their utility in evaluating the dural venous sinuses. Noncontrast MRV may be performed in the event that contrast cannot be administered.


Orbits Vision and Visual Loss


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Variant 8: Ophthalmoplegia or diplopia. Initial imaging. Ophthalmoplegia is paralysis of one or more extraocular muscles. This may be caused by impaired motility of the muscles, disrupted nerve conduction along the neuromuscular junction, or from denervation of the affected cranial nerve or brainstem nucleus. Ophthalmoplegia may also be related to granulomatous, inflammatory, neoplastic, and traumatic abnormalities that primarily affect the extraocular muscles. Traumatic orbital injury is covered in Variant 1 of this document.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Patients with isolated cranial nerve III palsies can be divided into pupil-involving or pupil-sparing, suggesting vascular compression versus vasculopathic etiologies, respectively. Isolated cranial nerve IV palsies are most often caused by trauma [63] and rarely nerve sheath tumors. Isolated cranial nerve VI palsies may be caused by


Orbits Vision and Visual Loss

Orbits, Vision and Visual Loss

Orbits Vision and Visual Loss. Orbits, Vision and Visual Loss


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. lesions within the prepontine cistern, skull base, cavernous sinus, or sella. Isolated cranial nerve VI palsies may also be seen in the setting of increased intracranial pressure without direct compression of the nerve [64]. Multiple ipsilateral cranial nerve palsies that affect cranial nerves III, IV, and VI suggest a lesion at the cavernous sinus or orbital apex [65] and can occur with pathology in the basilar subarachnoid space, as seen in infectious meningitis (TB, fungal, Lyme disease) or noninfectious causes (sarcoid, neoplasm, perineural, or leptomeningeal tumor spread). In patients with internuclear ophthalmoplegia, a brain-stem lesion affecting the medial longitudinal fasciculus should be suspected. A demyelinating plaque in the setting of multiple sclerosis is a primary consideration in younger patients and stroke in older patients presenting with an acute internuclear ophthalmoplegia [66]. Other likely considerations include tumor, hemorrhage, and infection [66].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. MRI MRI of the orbits without and with contrast is preferred [67] if ophthalmoplegia is felt to be related to a primary disease process within the orbit affecting the extraocular muscles or if there is history of trauma, enophthalmos, proptosis, orbital inflammation, or chemosis. An MRI of the orbits with the globes imaged during different gaze positions may aid in identifying a potential muscular slip or pulley abnormality [68].


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. CT In patients with ophthalmoplegia or diplopia with associated secondary signs of proptosis, orbital inflammation, or trauma, a dedicated orbit CT is typically indicated to evaluate the extraocular muscles. Contrast is often indicated in the setting of orbital inflammation assessment but not indicated in the acute traumatic setting, as specified in Variant 1. CT is superior to MRI for foreign body assessment, calcification detection, and osseous evaluation [43]. Although CT imaging of the orbits is preferred, CT imaging of the head may be appropriate if an intracranial abnormality is suspected. Precontrast and postcontrast imaging of the orbits is typically not necessary in evaluating these patients as the precontrast images do not add significant diagnostic information in this scenario.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Radiography Orbital or skull radiographs are insufficient to detect pathology in patients presenting with proptosis and have primarily been supplanted by CT.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Summary of Recommendations Orbital trauma is best assessed with a noncontrast orbit CT and/or noncontrast CT of the head, which are often complementary. Orbital asymmetry, exophthalmos, or enophthalmos can be evaluated with contrast-enhanced orbit CT or contrast-enhanced orbit MRI, which are often complementary. Contrast-enhanced CT or contrast-enhanced MRI are both appropriate in evaluating orbital cellulitis, uveitis, or scleritis, with CT often performed first during the initial assessment. Optic neuritis is best assessed with a contrast-enhanced MRI of the orbits and contrast-enhanced MRI of the head, which are often performed in conjunction with one another.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Although there are references that report on studies with design limitations, 4 well-designed or good-quality studies provide good evidence.


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Appropriateness Category Names and Definitions Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at


Orbits Vision and Visual Loss

Orbits, Vision and Visual Loss


Orbits Vision and Visual Loss

Orbits Vision and Visual Loss. Supporting Documents For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Introduction/Background Osteoporosis is a systemic skeletal condition characterized by reduced bone density and deterioration of osseous tissue that leads to bone fragility and increased susceptibility to fracture [1]. Bone strength is a product of bone mineral density (BMD), a quantifiable property, and the integrity of trabecular microarchitecture. Currently, the consensus approach to screening and monitoring osteoporosis in the population is measurement of BMD, which is an effective way to identify patients who are at risk for fracture. An estimated 10.2 million adults in the United States >50 years of age have osteoporosis; however, the aging of the population is projected to increase this number by >30% by 2030, even though most experts agree that osteoporosis is generally underdiagnosed [2,3]. Approximately one-half of women and nearly one-third of men >50 years of age will sustain an osteoporotic fracture [4]. The yearly number of fractures is projected to increase from 1.9 million in 2018 to over 3.2 million fractures by 2040, with direct medical costs increasing from $48.8 billion to $81.5 billion during the same time range [5,6]. When indirect societal costs are also considered, the total projected cost could exceed $95 billion by 2040 [6].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Osteoporotic fractures are associated with subsequent fractures and premature mortality. In patients who have sustained a fracture, 10% will have another within 1 year, 18% within 2 years, and 31% within 5 years [7]. The first-year mortality rate is 20%, but there is also a 3- to 4-fold increased risk of mortality in the subsequent 5 years following any fragility fracture [8]. It is highest after sustaining a hip fracture, where there is a 1-year mortality of 24% in women and 38% in men [9]. Fragility fractures are also associated with a decrease in quality of life, diminished physical function, and reduced independence [10]. Given the proven efficacy of pharmacologic therapy, the role of imaging to appropriately identify and monitor high-risk individuals is critical in substantially reducing osteoporosis-associated morbidity and mortality.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Special Imaging Considerations Dual-energy X-ray absorptiometry (DXA) is the mainstay of bone densitometry to screen for osteopenia and osteoporosis. Because this modality relies on precision, it is essential for patients to be scanned on the same DXA machine because differences in vendor technologies prohibit a direct comparison unless cross calibration has been performed [11,12].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. CT is a cross-sectional-based X-ray technology that uses tomographic technique coupled with computer processing to generate a cross-sectional image. CT has a higher sensitivity to subtle differences in electron densities than radiography and therefore creates an image with markedly improved contrast.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Quantitative CT (QCT) is performed on a standard clinical scanner and is highly accurate in determining tissue density within a region of interest. Scanning sites for QCT include the lumbar spine and hip. Several studies have assessed using conventional CT scans for measurement of bone density by establishing threshold Hounsfield unit levels that are diagnostic for osteopenia and osteoporosis, but this concept remains an opportunistic use of CT and not a screening tool [13-15]. High-resolution peripheral QCT uses the same technology in a smaller dedicated machine and focuses on the distal radius and tibia. Currently, peripheral QCT studies are not approved for diagnosis


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. aThe Ohio State University Wexner Medical Center, Columbus, Ohio. bResearch Author, Ohio State University, Columbus, Ohio. cPanel Chair, Mayo Clinic Arizona, Phoenix, Arizona. dUniversity of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. eMayo Clinic, Rochester, Minnesota. fHospital for Special Surgery, New York, New York. gThe Ohio State University Wexner Medical Center, Columbus, Ohio, Primary care physician. hMedical University of South Carolina, Charleston, South Carolina; North American Spine Society. iDuke University Medical Center, Durham, North Carolina. jUniversity of Missouri Health Care, Columbia, Missouri. kCleveland Clinic, Cleveland, Ohio. lPenn State Milton S. Hershey Medical Center, Hershey, Pennsylvania, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania; Commission on Nuclear Medicine and Molecular Imaging. mPenn State Milton S. Hershey Medical Center, Hershey, Pennsylvania and Uniformed Services University of the Health Sciences, Bethesda, Maryland. nSpecialty Chair, University of Kentucky, Lexington, Kentucky.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. 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.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Reprint requests to: publications@acr.org


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Osteoporosis and Bone Mineral Density


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. of osteoporosis, although it has research applications in determining alterations in the bone architecture. It should be noted that peripheral QCT is commonly performed in children [16].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Additional risk factors for osteoporosis include: a. Estrogen deficiency b. A history of maternal hip fracture that occurred after the age of 50 years c. Low body mass (<127 lb or 57.6 kg) d. History of amenorrhea (>1 year before 42 years of age) 3. Women <65 years of age or men <70 years of age who have additional risk factors, including:


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. DXA DXA DXA is recommended for osteoporosis screening or initial imaging of clinically suspected low BMD. It is a clinically proven method of measuring BMD in the lumbar spine, proximal femur, forearm, and whole body. BMD measurements derived from DXA has been shown to accurately predict fracture risk [18,19]. Epidemiological studies have demonstrated that BMD correlates to population fracture risk and amount of force necessary to fracture bone [20,21].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. In a routine DXA study, 2 sites (the lumbar spine and hip) are reported. In the spine, a frontal projection measures up to 4 vertebral bodies from L1 to L4, and in the hip, a frontal projection measures 2 regions: the femoral neck and total hip [17]. In the event of a falsely elevated BMD of the lumbar spine caused by fracture, facet joint osteoarthritis, or spondylosis, up to 2 vertebral levels may be excluded from analysis. However, if exclusion of more than 2 vertebral body levels is necessary, then the second hip can be scanned as a substitute for the spine [22]. Alternatively, the distal one-third radius of the nondominant arm may be used as a third site in situations in which only one hip is available. Otherwise, the distal one-third radius is used primarily in patients with hyperparathyroidism. Primary hyperparathyroidism preferentially decreases mineralization at cortical-rich sites such as the hip and mid radius, in contrast to the predominantly cancellous bone of the lumbar spine [22].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Although DXA is an accurate screening tool, it remains underused. According to 2 recent reports, only 6.7% of patients underwent evaluation with DXA 6 months after sustaining a fragility fracture in 1 study, and only 8% of patients on long-term glucocorticoid therapy had follow-up DXAs [29,30]. Underutilization may lead to under- treatment in approximately 70% of these patients, and patients who are not adequately treated are at increased risk of incurring additional fractures in their lifetime [7,29].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. QCT QCT QCT also provides volumetric BMD (vBMD), and both the trabecular and cortical bone compartments can be assessed [31,32]. QCT can be performed on a vast majority of commercially available CT scanners, provided they include densitometry analysis software and a calibration phantom. When interpreting QCT vBMD results, it is important to recognize 2 important differences to DXA. Z- and T-scores can be calculated from the vBMD, but the T-scores do not apply to the WHO definition of osteoporosis or osteopenia [31]. The exclusive application of the WHO classification is inherent to projectional BMD [25]. The ACR QCT cutoff values for low bone mass or osteopenia are 80 to 120 mg/mL and <80 mg/mL for osteoporosis [12]. Another major difference between QCT and DXA is related to monitoring. Spine BMD values measured by QCT demonstrate higher rates of bone loss with advancing age, principally because of the exclusive measurement of cancellous bone. The rate of change in cancellous bone is significantly greater than that of cortical bone. By contrast, the projectional properties of DXA summate the cortically predominant end plates and posterior elements with the cancellous vertebral body measurements, thereby decreasing their rate of change over time [31].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Indications for utilization of QCT as a screening modality are the same as DXA. However, in the setting of screening or initial imaging, QCT is regarded as a secondary tool to DXA. QCT may be considered as a primary imaging modality in certain conditions. Cases in which QCT is considered superior to DXA include extremes in height (very tall and very small patients), patients with obesity (BMI >35 kg/m2), patients with severe degenerative spine disease, and when an increased sensitivity to small changes in trabecular bone density is desired (parathyroid hormone and glucocorticoid treatment monitoring) [34]. It was recently reported that opportunistic QCTs of the lumbar spine was more predictive of spine fractures in neurological and oncologic patients than reference DXA scans, but there were only 84 patients in this study [35].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. QUS There is insufficient evidence to support the current use of quantitative ultrasound (QUS) as a screening tool in patients suspected of having osteoporosis or low BMD. Dense structural complexity demonstrates increased attenuation, whereas osteoporotic bone demonstrates lower velocities. The limitations of QUS are a lack of precision and sensitivity [36]. Dedicated QUS scanners are available for the calcaneus, phalanx, and tibia. However, the heel represents the only validated site for the clinical use of QUS. QUS does not measure BMD, and therefore, the WHO


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Osteoporosis and Bone Mineral Density classification system cannot be used and a diagnosis of osteoporosis cannot be made. Discordance between QUS and central DXA is not infrequent [37]. A recent meta-analysis conducted to assess the role of QUS in inflammatory rheumatic diseases came to the conclusion that the current literature does not support the substitution of QUS for DXA in the diagnosis and monitoring of osteoporosis in rheumatic diseases [38].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Radiography Appendicular Skeleton There is insufficient evidence to support the current use of radiography as a screening tool in patients suspected of having osteoporosis or low BMD. Radiography is a projectional X-ray-based technology that is widely used in current medical practice for rapid image acquisition for an extensive number of indications. Radiography use differences in electron density to generate contrast between different tissues, including bone. Although there are several standards used to identify demineralized bone on radiographs, radiography has a substantially lower sensitivity to bone loss than DXA. Osteopenia is not a reliable finding until 30% to 40% of the bone has been lost [39]. Patients who have radiographic evidence of osteopenia and/or fragility fractures should be referred to DXA for further characterization.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Radiography Axial Skeleton There is insufficient evidence to support the current use of radiography as a screening tool in patients suspected of having osteoporosis or low BMD. Reportedly, patients with a low second metacarpal index may have a higher risk for developing hip fractures [40]. A recent study using artificial intelligence to segment metacarpal morphometry has shown potential as a screening tool with a sensitivity of 82.4% and specificity of 95.7% and a pipeline accuracy of nearly 94% [41]. Patients who have radiographic evidence of demineralization and/or fragility fractures should be referred to DXA for further characterization.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. SXA There is insufficient evidence to support the current use of single X-ray (SXA) in patients suspected of having osteoporosis or low BMD. SXA is a projectional X-ray-based technology that used one X-ray tube as a photon source and was shown to precisely measure BMD at the forearm. It is no longer widely used in current practice and has been supplanted by DXA.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. TBS Although DXA provides an accurate evaluation of BMD, it is not always an accurate predictor of fracture risk because there is considerable overlap between BMD values in individuals with and without fractures. Trabecular bone score (TBS) is an independent predictor of fracture risk because TBS values quantify bone microarchitecture, a determinant of bone strength [42]. This analytical tool performs textural analysis on 2-D lumbar spine DXA images and captures information by measuring grey-level variations from one pixel to adjacent pixels, providing 3- D bone characteristics such as trabecular number, trabecular separation, and the connectivity density [43]. There is evidence that TBS can differentiate between two 3-D microarchitectures that exhibit identical BMD measurements bone quality rather than bone quantity as measured by DXA, QCT, and ultrasound. Elevated values of TBS correlate with fracture resistance, whereas porous osteoporotic bone depict lower values than normal bone [44]. The advantages of TBS are that it can be assessed retrospectively from previously obtained DXA scans providing longitudinal data, and it is not impacted by the presence of overlying calcifications or degenerative changes in the spine [45].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. In the setting of screening or initial imaging, TBS is regarded as an adjunct tool to DXA. However, TBS should not be used alone in clinical practice either to screen for osteoporosis or for treatment decisions [17]. TBS may be useful in certain populations. TBS when used in conjunction with BMD, clinical risk factors, and/or FRAX consistently enhances their accuracy [46-50]. Significantly reduced TBSs are associated with fragility fractures in secondary osteoporosis. In these patients, TBS has been found to have a substantially higher association with fracture risk than BMD [51,52]. TBSs in patients with type 2 diabetes, chronic renal disease, glucocorticoid therapy, rheumatoid arthritis, and hyperparathyroidism have demonstrated increased fracture risk, even in the setting of normal BMD [47,53].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Variant 2: Follow-up imaging of patients demonstrated to have risk for fracture or surveillance of established low bone mineral density. Follow-up imaging is recommended in patients who have increased risk for fracture, been previously diagnosed with osteopenia or osteoporosis, or initiated treatment for osteoporosis. Additionally, as outlined in Variant 3, vertebral fracture assessment (VFA) may be considered in patients with documented spine fractures or if they have


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. been diagnosed with osteopenia and meet certain age criteria, have experienced height loss or undocumented vertebral fractures (VFs), or have a history of use of glucocorticoid medication for >3 months.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. When a nontreated patient has a statistically significant decrease in BMD on follow-up DXA, therapy initiation may be considered in the setting of confirmed primary osteoporosis or when there is clinical correlation identifying potential secondary causes of osteoporosis [57]. Serial BMD testing combined with clinical risk factors, bone turnover markers, and other factors such as height loss and TBS may also be used to determine whether treatment should be initiated. Patients receiving treatment who demonstrate decreasing BMD on follow-up scans may require an adjustment in their pharmacotherapy regimen [24].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. In the majority of patients, the time interval for monitoring is based on the change rate of bone mineralization, which is typically about 2 years; however, it is preferable for this interval to be shorter (1 to <2 years) after therapy has been initiated [23]. Patients who are at high risk for a more rapid decline of bone mass, such as those receiving glucocorticoid therapy, also require shorter intervals between imaging; 1-year intervals after initiation or change of therapy is appropriate with progressively longer intervals once therapeutic effect is established [58]. Scan intervals <1 year are discouraged [24]. Serial BMD testing is encouraged in individuals after cessation of pharmacologic therapy for osteoporosis as well.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. DXA VFA In this setting, use of VFA is not supported. This differs from variant 3 in which VFA may be considered in patients with documented spine fractures or if they have been diagnosed with osteopenia and meet certain age criteria, have experienced height loss or undocumented VFs, or have a history of use of glucocorticoid medication for >3 months [17].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. QCT QCT is regarded as a secondary or adjunct tool to DXA. QCT may be useful in unique populations in which there is a need for added precision. QCT demonstrates excellent precision and reproducibility to changes and can be used for the monitoring of BMD in untreated and treated patients provided that there is routine calibration [22]. QCT is more sensitive to change than DXA because it detects mineralization in the cancellous bone, the portion of bone most sensitive to rapid changes, as well as at the cortex, such as newly formed bone in the cortical and subcortical compartments [61-63]. Femoral neck and total hip T-scores calculated from follow-up projectional QCT data are equivalent to corresponding DXA T-scores for monitoring of osteoporosis in accordance to the WHO criteria, and can be used longitudinally [22].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. QUS There is insufficient evidence to the support the routine use of QUS for monitoring of untreated and treated patients.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. SXA There is insufficient evidence to the support the routine use of SXA for monitoring of untreated and treated patients.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Osteoporosis and Bone Mineral Density TBS TBS is regarded as an adjunct tool to DXA. TBS may be useful in a small population where there is a need to look at marginal changes beyond BMD. TBS may be of benefit stratifying risk in individuals with relatively normal or osteopenic BMD values because most fractures occur in this subset of nonosteoporotic patients. Multiple studies have shown associations of TBS with fractures in postmenopausal women as well as a few fractures in men [64- 68].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. DXA Follow-up DXA is supported for monitoring patients who have low BMD and VF risk factors [56].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. DXA VFA In their 2019 guidelines, the ISCD recommended that densitometric spine imaging, or VFA, be considered for the listed indications in this variant [17]. VFA is a feature of DXA scanners in which a lateral thoracic and lumbar spine image from T5 to L5 is provided for the purpose of detecting vertebral body deformities; most VFs occur between the T7 and L4 levels [77]. This procedure is complementary to DXA; the image is obtained during the DXA session and represents a point-of-care service. A semiquantitative visual method used for diagnosis characterizes the morphology based on shape (wedge, concave, or crush) and location (anterior, posterior, and/or middle) and the total number of involved vertebrae [78,79]. In general, grade 2 fractures (moderate or 26%-40% reduction) and grade 3 fractures (severe or >40% reduction) are more predictive of future fractures than grade 1 fractures (mild or 20%-25% reduction), which have a greater overlap with nonfracture deformities [80]. A solitary, asymptomatic grade 1 fracture is likely to be minimal to no clinical significance, whereas a grade 3 fracture is an important predictor of fracture risk not only in the spine but also in nonvertebral sites [81].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. It is estimated that two-thirds of radiographically evident VFs are not recognized clinically and are incidentally detected [82]. Numerous epidemiologic studies have provided the incidence and prevalence of VFs in different populations [83-85]. The risk for developing a VF rises substantially in women after >70 years of age and in men >80 years of age [86-88]. In patients with chronic exposure to glucocorticoid medication, the prevalence of VF is >50% in those >70 years of age, approximately 17% in patients treated for autoimmune disease, and 22% in patients with Crohn disease [89-91]. The incidence is 2 to 2.5 times higher in women than in men [77].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. The utility of VFA is identifying patients who would not otherwise qualify for treatment under the guidelines of the NOF, which are based solely on BMD measurements. Multiple studies have demonstrated populations of patients who were reclassified because of detection of VFs [92-95]. A study in the Netherlands demonstrated that 60% of patients with a fracture on VFA were in the nonosteoporotic range, and of these, 74% were previously unknown to have fractures [92]. In another recent study of postmenopausal women, 17.2% of patients had their diagnosis upgraded to severe osteoporosis owing to VFs diagnosed on VFA [96]. A meta-analysis based on VFA-detected VFs reported that among women who had prevalent VFs, up to 43% had low BMD (osteopenia), and up to 32% had normal bone density [76]. Detection of unknown VFs influences initiating therapy in asymptomatic patients as well as guides therapeutic decisions in treated patients whose BMD may have remained stable or shown improvement on DXA [97].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Osteoporosis and Bone Mineral Density QCT QCT is regarded as a secondary or adjunct tool to DXA. It may be considered as a primary modality in cases in which there is severe degenerative disease of the spine or significant scoliosis (see Variant 6) and when it is desirable to have higher spatial resolution to optimize bone detail.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. QUS There is insufficient evidence to support the use of QUS to image the spine.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Radiography Appendicular Skeleton There is insufficient evidence to support the use of appendicular radiography to image the spine.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Radiography Axial Skeleton Lateral radiographs of the spine may be considered when VFA is not diagnostic or when images cannot be adequately derived. Additionally, radiographs of the spine may be considered as an alternative to VFA in patients who have low BMD and risk factors for developing VFs [17]. The benefit of radiography over VFA is superior spatial resolution. The sharp delineation of the end plates and cortical margins affirms confident detection of subtle Genant grade 1 fractures [98]. When reporting the severity of a vertebral body defect, the semiquantitative methodology by Genant should be used [78].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. SXA There is insufficient evidence to support the use of SXA to image the spine.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. TBS TBS is regarded as an adjunct tool to DXA. TBS may be useful in a small population in which there is a need to look at marginal changes beyond BMD. TBS enhances FRAX in patients whose BMD level lies close to the intervention threshold and may provide data that facilitates treatment decisions, but TBS should not be used by itself in monitoring patients with VF risk factors [47].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Variant 4: Initial imaging for premenopausal females or males less than 50 years of age. Individual with risk factors that could alter bone mineral density. 1. Individuals with medical conditions that could alter BMD, such as:


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. DXA The data providing imaging guidance in premenopausal women are few. The literature indicates that DXA remains the primary screening modality for evaluating bone mineralization in patients with these clinical scenarios [99]. Screening BMD should not be performed in premenopausal women. The 2 exceptions are young women with a history of fractures from minor trauma and those who have known causes of bone loss [100,101]. Chronic disease damage and low BMI are reported as risks factors for low BMD in premenopausal systemic lupus erythematosus patients, and early monitoring and/or treatment may prevent severe bone loss and future fractures [102]. In the 2017 American College of Rheumatology guidelines on glucocorticoid-induced osteoporosis, adults receiving


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Osteoporosis and Bone Mineral Density


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. glucocorticoid therapy for >3 months and who have had a prior fracture or other risk factors should have their BMD evaluated every 2 to 3 years [103]. In organ transplant patients, owing to rapid bone loss in the first 6 to 12 months after transplantation, the same imaging guideline was proposed [103].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. A baseline DXA should be considered in women age <40 years of age who experience premature menopause for any reason, especially when menopause was induced by chemotherapy. In untreated women undergoing initiation of an aromatase inhibitor, bone loss is most marked in the 12 to 24 months [104]. Men who undergo androgen deprivation therapy have substantially elevated risk of fracture. A baseline DXA study in men receiving androgen deprivation therapy should be considered after 6 months of therapy [105].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. QUS There is insufficient evidence to support the use of QUS as a screening study in this group of patients. The correlation between QUS parameters and DXA has been reported to be lower in premenopausal women than in postmenopausal women and not predictive of osteoporosis [109].


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Radiography Appendicular Skeleton There is insufficient evidence to support the use of radiography appendicular skeleton as a screening study in this group of patients.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Radiography Axial Skeleton There is insufficient evidence to support the use of radiography axial skeleton as a screening study in this group of patients.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. SXA There is insufficient evidence to support the use of SXA as a screening study in this group of patients.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. TBS There is insufficient evidence to support the use of TBS as a screening study in this group of patients.


Osteoporosis and Bone Mineral Density

Osteoporosis and Bone Mineral Density. Variant 5: Premenopausal females with risk factors. Males less than 50 years of age with risk factors. Follow- up to low bone mineral density. 1. Individuals with medical conditions that could alter BMD, such as: