Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . CTU Without and With IV Contrast With urinary tract opacification, CTU confirms the ureteral location of a calculus, distinguishing from stone mimics such as an adjacent phlebolith or vascular calcification. CTU can better confirm the degree of obstruction caused by a ureteral stone and potentially also aid in diagnosing a radiolucent stone that may not be visualized with


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . Acute Onset Flank Pain-Suspicion of Stone Disease noncontrast CT. However, there is no relevant literature documenting the benefit of additional CTU in a patient with known current stone disease, diagnosed on recent imaging with recurrent symptoms of stone disease.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . MRI Abdomen and Pelvis Without and With IV Contrast There is no relevant literature documenting the additional benefit of MRI without and with IV contrast in a patient with known current stone disease, diagnosed on recent imaging with recurrent symptoms of stone disease.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature documenting the additional benefit of MRI without IV contrast in a patient with known current stone disease, diagnosed on recent imaging with recurrent symptoms of stone disease.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . MRU Without and With IV Contrast There is no relevant literature documenting the additional benefit of MRU without and with IV contrast in a patient with known current stone disease, diagnosed on recent imaging with recurrent symptoms of stone disease. However, MRU has been shown in the setting of initial stone detection to be more sensitive than noncontrast CT in the detection of secondary signs of obstruction in the presence of urolithiasis, although this has not been specifically assessed in this clinical scenario [28].


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . MRU Without IV Contrast There is no relevant literature documenting the additional benefit of MRU without IV contrast in a patient with known current stone disease, diagnosed on recent imaging with recurrent symptoms of stone disease.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . Radiography Abdomen and Pelvis If a stone was initially radiopaque on initial KUB and/or CT, a follow-up KUB could indicate whether a stone has migrated/changed in position. However, there is no relevant literature documenting the benefit of KUB in a patient with known current stone disease, diagnosed on recent imaging with recurrent symptoms of stone disease.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . Radiography Intravenous Urography With urinary tract opacification, IVU may confirm the ureteral location of a calculus, distinguishing from stone mimics such as an adjacent phlebolith or vascular calcification. However, there is no relevant literature specifically assessing its use/benefit in this clinical scenario.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . US Color Doppler Kidneys and Bladder Retroperitoneal There is no evidence to support the use of dedicated US color Doppler in the evaluation of patients with known current stone disease, diagnosed on recent imaging with recurrent symptoms of stone disease. This procedure is intended for evaluation of vasculature.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . US Kidneys and Bladder Retroperitoneal Using grayscale techniques, US demonstrates variable performance in the detection of renal calculi depending on the clinical scenario but is used to assess for associated complications such as hydronephrosis. In one study, using US to guide clinical decision-making for patients with known residual calculi is limited by low sensitivity and the inability to size the stone accurately, which can lead to inappropriate counseling for patients [36].


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . Variant 3: Pregnant patient. Acute onset flank pain. Suspicion of stone disease. Initial or follow-up imaging. Stones can be a source of abdominal pain in pregnant patients. Urolithiasis can also be associated with hydronephrosis if there is a component of obstruction; however, the differential diagnosis of hydronephrosis in the pregnant patient is confounded by ph ysiologic hy dronephrosis o f pregnancy, which is thought to be caused by compression of the ureters between the gravid uterus and the linea terminalis [46]. Physiologic hydronephrosis of pregnancy occurs in >80% of pregnant patients, more commonly occurs on the right than the left, and is generally seen beginning in the second trimester [46].


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . CT Abdomen and Pelvis With IV Contrast There is no relevant literature documenting the additional benefit of CT abdomen and pelvis with IV contrast, relative to noncontrast CT, in the pregnant patient for the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature documenting the additional benefit of CT abdomen and pelvis without and with IV contrast, relative to noncontrast CT alone, in the pregnant patient for the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . Acute Onset Flank Pain-Suspicion of Stone Disease CT Abdomen and Pelvis Without IV Contrast CT abdomen and pelvis without IV contrast has been shown to be a sensitive and specific test for diagnosing stones in pregnant patients [47]. The key consideration in CT studies for pregnant patients with suspected urolithiasis is mitigating effects of radiation dose by optimizing dose in each study and reducing the overall number of imaging studies to the lowest number possible.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . CTU Without and With IV Contrast There is no relevant literature documenting the additional benefit of CTU without and with IV contrast, relative to noncontrast CT alone, in the pregnant patient for the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature documenting the additional benefit of MRI without IV contrast without dedicated urographic imaging, relative to noncontrast MRU, in the pregnant patient for the evaluation of stones; however, it can be helpful in follow-up imaging for stones and/or hydronephrosis, particularly if US is limited.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . MRI Abdomen and Pelvis Without and With IV Contrast There is no relevant literature documenting the additional benefit of MRI without and with IV contrast, relative to noncontrast MRU, in the pregnant patient for the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . MRU Without and With IV Contrast There is no relevant literature documenting the additional benefit of MRU without and with IV contrast, relative to noncontrast MRU, in the pregnant patient for the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . MRU Without IV Contrast With a goal of avoiding irradiation of the fetus, MRU has also been advocated for the detection of ureteral calculi at some centers [48] as well as hydronephrosis or other cause of renal obstruction. However, in a study by Shokeir et al [49] in nonpregnant patients, the site of stone impaction was identified by noncontrast CT in 146 of 146 renal units (100% sensitivity) and by MRU in only 101 of 146 renal units (69% sensitivity). A survey of academic medical centers found that radiologists are more likely to image for suspected renal calculus with CT than with MR in the second (35% versus 20%) and third (48% versus 18%) trimesters [50].


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . Radiography Abdomen and Pelvis There is no relevant literature documenting the benefit of KUB in the pregnant patient for the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . Radiography Intravenous Urography Limited IVU (example: scout radiograph, film at 30 seconds and film at 20 minutes) has also been used to diagnose ureteral obstruction in pregnant patients [51].


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . US Color Doppler Kidneys and Bladder Retroperitoneal There is no evidence to support the use of dedicated US color Doppler in the evaluation of pregnant patients with suspicion of stone disease. This procedure is intended for evaluation of vasculature.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . US Kidneys and Bladder Retroperitoneal US is frequently used as a screening examination, because US is a sensitive and specific test for diagnosing hydronephrosis and does not expose the patient or fetus to ionizing radiation [52-54].


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . Variant 4: Acute onset flank pain. Suspicion of stone disease. CT without contrast is inconclusive for the presence of stones. Next imaging study. In clinical practice, a no ncontract CT may b e inconclusive for stones when it is unclear whether an identified calcification is located within the ureter or an adjacent structure. Common mimics of ureteral stones in clude phleboliths or arterial calcifications. This uncertainty can be exacerbated in thin patients with a lack of sufficient fat planes separating the ureters from adjacent structures.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . Acute Onset Flank Pain-Suspicion of Stone Disease enhanced CT does also allow for the evaluation of other etiologies of flank pain [43]. In studies evaluating the use of CT abdomen and pelvis with IV contrast following a noncontrast CT, contrast-enhanced CT provided additional information or revealed a new diagnosis in 5% to 18% of cases, while ultimately changing clinical management in only 2% to 3% of cases [44,45].


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature documenting the additional benefit of repeat noncontrast CT followed by CT abdomen and pelvis with IV contrast after an inconclusive CT without IV contrast in the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . CT Abdomen and Pelvis Without IV Contrast There is no relevant literature documenting the additional benefit of repeat noncontrast CT after an inconclusive CT without IV contrast in the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . CTU Without and With IV Contrast With urinary tract opacification, CTU confirms the ureteral location of a calculus, distinguishing from stone mimics such as an adjacent phlebolith or vascular calcification. CTU can better confirm the degree of obstruction caused by a ureteral stone and potentially also aid in diagnosing a radiolucent stone that may not be visualized with noncontrast CT and can also detect urothelial masses on the excretory phase. However, there is no relevant literature documenting the additional benefit of additional CTU after an inconclusive CT without IV contrast in the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . MRI Abdomen and Pelvis Without and With IV Contrast There is no relevant literature documenting the additional benefit of MRI without and with IV contrast after an inconclusive CT without IV contrast in the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature documenting the additional benefit of MRI without IV contrast after an inconclusive CT without IV contrast in the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . MRU Without and With IV Contrast There is no relevant literature documenting the additional benefit of MRU without and with IV contrast after an inconclusive CT without IV contrast in the evaluation of stones. However, MRU has been shown in the setting of initial stone detection to be more sensitive than noncontrast CT in the detection of secondary signs of obstruction in the presence of urolithiasis, although this has not been specifically assessed in this clinical scenario [28].


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . MRU Without IV Contrast There is no relevant literature documenting the additional benefit of MRU without IV contrast after an inconclusive CT without IV contrast in the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . Radiography Abdomen and Pelvis There is no relevant literature documenting the additional benefit of KUB after an inconclusive CT without IV contrast in the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . Radiography Intravenous Urography With urinary tract opacification, IVU may confirm the ureteral location of a calculus, distinguishing from stone mimics such as an adjacent phlebolith or vascular calcification. However, there is no relevant literature documenting the additional benefit of IVU after an inconclusive CT without IV contrast in the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . US Color Doppler Kidneys and Bladder Retroperitoneal There is no evidence to support the use of dedicated US color Doppler after an inconclusive CT without IV contrast in the evaluation of stones. This procedure is intended for the evaluation of vasculature.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . US Kidneys and Bladder Retroperitoneal There is no relevant literature documenting the additional benefit of US after an inconclusive CT without IV contrast in the evaluation of stones.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . 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.


Acute Onset Flank Pain Suspicion of Stone Disease Urolithiasis . For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Suspected Lower Extremity Deep Vein Thrombosis. It is clinically important to determine the location and extent of DVT [3,6]. DVT that is limited to the infrapopliteal calf veins (ie, below-the-knee or distal DVT) often resolves spontaneously and is rarely associated with pulmonary embolism or other adverse outcomes [3,7,8]. Above-the-knee or proximal DVT, on the other hand, is strongly associated with an increased risk for pulmonary embolism. The treatment of choice for DVT is anticoagulation to reduce the risk of DVT extension, recurrent DVT, pulmonary embolism, and post-thrombotic syndrome. It is generally accepted that the benefits of anticoagulation therapy in patients with proximal DVT outweigh its risks [3,6]. Because below-the-knee DVT rarely results in pulmonary embolism, the role of anticoagulation therapy in patients with distal DVT remains controversial [3,6,9]. However, because one-sixth of patients with distal DVT experience extension of thrombus proximally above the knee, serial imaging to exclude proximal DVT extension is recommended at 1 week if anticoagulation therapy is not initiated at presentation [3,6]. This issue is complicated by the variability in evaluation for below-the-knee DVT as part of a routine examination.


Suspected Lower Extremity Deep Vein Thrombosis. Classically, a patient with symptomatic lower extremity DVT presents with either local pain or tenderness or with edema and swelling of the lower extremity. However, approximately one-third of patients with DVT do not have any symptoms [10]. Often, symptoms are not apparent until there is involvement above the knee [3]. The clinical diagnosis of DVT using clinical risk-stratification scores (eg, Wells score) alone has, therefore, been less than ideal [10]. Wells et al [11,12] suggested using a clinical DVT-prediction score (aka, Wells score) in combination with a blood evaluation for plasma D-dimer, a degradation product of cross-linked fibrin that is elevated during thromboembolic events. DVT is unlikely if the clinical prediction score is low and the D-dimer levels are normal [3,6,10-12]. However, the highly variable nature of DVT presentation, numerous potential pathologic mimics for DVT, and variations in D-dimer assay performances in certain populations limit the reliability of diagnosis solely on the clinical DVT prediction score and D-dimer testing. DVT screening of select high-risk patients in intensive care units because of prolonged immobility has also shown benefit [13,14]. Lower extremity ultrasound (US) has also been included in an algorithm for the workup of patients who have a fever of unknown origin after more common causes have been excluded [15,16].


Suspected Lower Extremity Deep Vein Thrombosis. Imaging is frequently required to definitively exclude DVT and properly document the extent of venous thrombosis, which is critical for proper therapeutic management of DVT. Moreover, the clinical-prediction score


Suspected Lower Extremity Deep Vein Thrombosis. 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.


Suspected Lower Extremity Deep Vein Thrombosis. Reprint requests to: publications@acr.org


Suspected Lower Extremity DVT

Suspected Lower Extremity Deep Vein Thrombosis. Suspected Lower Extremity DVT


Suspected Lower Extremity Deep Vein Thrombosis. and D-dimer level are often unreliable for diagnosing recurrent DVT and are not useful for diagnosing alternative conditions, such as an intact or ruptured Baker cyst, cellulitis, lymphedema, chronic venous disease, and various musculoskeletal disorders that can clinically mimic DVT.


Suspected Lower Extremity Deep Vein Thrombosis. Discussion of Procedures by Variant Variant 1: Suspected lower extremity deep vein thrombosis. Initial imaging. Catheter Venography Pelvis and Lower Extremity Contrast catheter venography is the historic and de facto gold standard for diagnosing DVT [3,6,10,11]. With this technique, proximal compression tourniquets are applied, and a series of overlapping radiographs are obtained following an iodine-containing contrast medium injection into a dorsal vein in the foot. DVT is present if a distinct filling defect is present in a deep vein, typically in the calf or thigh, but it can often extend to or involve more proximal veins, such as those in the pelvis. Less specific findings for DVT include an abrupt contrast cut- off, the absence of contrast filling, or the presence of collateral venous vessels. Although the techniques have evolved to catheter-directed venography using fluoroscopy, the risks and benefits are felt to be the same.


Suspected Lower Extremity Deep Vein Thrombosis. MR Venography Lower Extremity and Pelvis MR venography (MRV) is a noninvasive alternative to contrast catheter venography. MRV does have inherent advantages over US, especially in its ability to delineate extravascular anatomy. MRV can help identify potential sources of extrinsic venous compression (ie, May-Thurner syndrome or a mass) that can be an underlying cause for DVT or suggest alternative diagnoses that mimic DVT.


Suspected Lower Extremity DVT


Suspected Lower Extremity Deep Vein Thrombosis. specificity, 95.2%) comparable to that of US for diagnosing proximal DVT [23]. CTV can also be incorporated into a comprehensive examination that includes pulmonary CT angiography for evaluating both pulmonary embolism and proximal DVT [26], but it should not be performed routinely in all patients who are being evaluated for pulmonary embolism [27]. There is little evidence to support the use of CTV to diagnose DVT; however, based on the published experience with pulmonary embolism, CTV may be considered a reasonable alternative to MRV for pelvic DVT or when US is nondiagnostic.


Suspected Lower Extremity Deep Vein Thrombosis. Summary of Recommendations Variant 1: US duplex Doppler lower extremity is the recommended initial imaging examination for patients with suspected lower extremity DVT.


Suspected Lower Extremity Deep Vein Thrombosis. Although there are references that report on studies with design limitations, 6 well-designed or good-quality studies provide good evidence.


Suspected Lower Extremity Deep Vein Thrombosis. Appropriateness Category Names and Definitions Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, because of both organ sensitivity and longer life expectancy (relevant to the long latency that appears to accompany radiation exposure). For these reasons, the RRL dose estimate ranges for pediatric examinations are lower as compared with those specified for adults (see Table below). Additional


Suspected Lower Extremity Deep Vein Thrombosis. Supporting Documents For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Second and Third Trimester Screening for Fetal Anomaly. Introduction/Background Major congenital anomalies occur in 3% to 4% and minor anomalies occur in 7% to 10% of the population [1-3]. Anomalies increase the risk of aneuploidy, syndromes, and poor outcome [2]. Congenital anomalies account for 22.1% of infant deaths, with fetal malformations causing increased morbidity and mortality in the neonatal/postnatal period [3].


Second and Third Trimester Screening for Fetal Anomaly. 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.


Second and Third Trimester Screening for Fetal Anomaly. Reprint requests to: publications@acr.org


Second and Third Trimester Screening for Fetal Anomaly. Second and Third Trimester Screening for Fetal Anomaly Special Imaging Considerations Transvaginal US The transvaginal US scan can be performed to supplement a transabdominal US scan where a fetal body part is close to the cervix and cannot be visualized transabdominally. Transvaginal US at 12 to 16 weeks can improve evaluation of fetal anatomy in obese women [8,10,21,22].


Second and Third Trimester Screening for Fetal Anomaly. 3-D and 4-D US Both 3-D and 4-D US have been helpful to further evaluate anatomy, especially facial clefts, spine anomalies such as hemivertebra, and midline brain anomalies such as agenesis of the corpus callosum or abnormalities of the posterior fossa [23,24]. In addition, 3-D and 4-D US [25] can be used as an adjunct to fetal echocardiography [26].


Second and Third Trimester Screening for Fetal Anomaly. CT CT has an extremely limited role to play in evaluation of the fetus, predominantly restricted to some cases of skeletal anomalies [27].


Second and Third Trimester Screening for Fetal Anomaly. OR Discussion of Procedures by Variant Variant 1: Second and third trimester screening for fetal anomaly. Low-risk pregnancy. Initial imaging. In the developed world, US is usually performed at least once during pregnancy [28]. A review of 11 randomized trials and quasi-randomized trials looked at outcomes for US performed routinely versus selective US at <24 weeks. Although perinatal mortality was not affected, there was increased detection of fetal anomalies, improved detection of multiple gestations, and lower rates of induction for postdates. Long-term follow-up of children exposed to US in utero showed no detrimental effects on cognitive or physical development, supporting the safety of US [9]. There are several systematic reviews and large studies, which report fetal anomaly detection rates between 16% and 56% on US performed prior to 24 weeks [5,8,9]. The rate of detection of lethal anomalies is higher, up to 84% [8,29].


Second and Third Trimester Screening for Fetal Anomaly. MRI Fetal Without and With IV Contrast There is no relevant literature to support the use of fetal MRI with and without intravenous (IV) contrast for screening of a fetal anomaly in a low-risk pregnancy.


Second and Third Trimester Screening for Fetal Anomaly. MRI Fetal Without IV Contrast There is no relevant literature to support the use of fetal MRI without IV contrast for screening of a fetal anomaly in a low-risk pregnancy.


Second and Third Trimester Screening for Fetal Anomaly. US Echocardiography Fetal There is no relevant literature to support the use of fetal echocardiography for screening of a fetal anomaly in a low- risk pregnancy.


Second and Third Trimester Screening for Fetal Anomaly. US Pregnant Uterus Transabdominal Detailed Scan There is no relevant literature to support the use of US pregnant uterus transabdominal detailed scan for screening of a fetal anomaly in a low-risk pregnancy.


Second and Third Trimester Screening for Fetal Anomaly. Second and Third Trimester Screening for Fetal Anomaly US Pregnant Uterus Transabdominal Anatomy Scan The Eunice Kennedy Shriver National Institute of Child Health and Human Development hosted a fetal imaging workshop in December 2012, resulting in a multispecialty panel recommending that at least one US be offered routinely to all pregnant women between 18 and 20 weeks of gestation [8]. The components of the standard fetal examination at 18 to 20 weeks have been agreed upon by several organizations and outlined in the ACR-ACOG- AIUM-SMFM-SRU Practice Parameter for the Performance of Standard Diagnostic Obstetrical Ultrasound [8,30].


Second and Third Trimester Screening for Fetal Anomaly. A routine diagnostic US may be used in the third trimester, either selectively or in the setting of a late arrival for assessment. Bricker et al [31] reviewed 13 trials with 34,980 patients and showed no evidence of improved antenatal, obstetric, or neonatal outcome or morbidity in those screened in the third trimester versus controls. A study by Manegold et al [32]; however, showed third trimester US to have utility for perinatal management and postnatal follow-up, with 15% of all anomalies found only in the third trimester in a study of 8,074 fetuses.


Second and Third Trimester Screening for Fetal Anomaly. Variant 2: Second and third trimester screening for fetal anomaly. High-risk pregnancy. Initial imaging. Detailed fetal anatomic examinations are performed in high-risk pregnancy instances where there is increased risk for anatomic or karyotypic fetal abnormality based on maternal factors (including age, use of in vitro fertilization, drug dependence, infection, or other maternal medical conditions) or abnormality of screening testing (including the quad screen, NIPT, or US findings). The category of high risk also includes family history of genetic disease or abnormality, multi-gestational pregnancies, and teen pregnancies [33]. A German study looked at teenage pregnancies in a database of all pregnancies from 2000 to 2011 and found 638 pregnancies in women <20 years of age, with a total of 9.2% of patients having anomalies or aneuploidy [34].


Second and Third Trimester Screening for Fetal Anomaly. Obese patients deserve special consideration as rates of congenital anomalies are increased, particularly involving neural tube defects, cardiovascular anomalies, cleft lip or palate, anorectal atresia, hydrocephaly, and limb reduction anomalies [35,36]. Several studies demonstrate decreased detection of fetal anomalies with increasing body mass index (likely related to suboptimal visualization) on routine and detailed examinations [36-40]. An anatomic survey in obese women should be considered at 20 to 22 weeks (about 2 weeks later than women of normal weight), and if incomplete, a repeat follow-up US should be considered in 2 to 4 weeks [8,40-44].


Second and Third Trimester Screening for Fetal Anomaly. There is emerging evidence that anatomic studies performed earlier in gestation with transvaginal imaging may be helpful [36-39]. A recent Canadian publication has demonstrated that performing early anatomic evaluation by transvaginal technique in combination with routine transabdominal study at 18 to 22 weeks can result in completion rates of the anatomic study that are comparable to those in nonobese populations [21]. This method should especially be considered in completion of the anatomic study in the high-risk obese population.


Second and Third Trimester Screening for Fetal Anomaly. MRI Fetal Without and With IV Contrast MRI abdomen and pelvis with IV contrast is not recommended for fetal evaluation. There are no documented fetal indications for the use of MRI contrast, but there may be rare instances where contrast is potentially helpful in evaluating maternal anatomy or pathology, to be decided on a case by case basis [45].


Second and Third Trimester Screening for Fetal Anomaly. MRI Fetal Without IV Contrast The International Society of Ultrasound in Obstetrics and Gynecology current guidelines recommend that fetal MRI is generally indicated following an US examination in which the information about the abnormality is incomplete. Although MRI is usually reserved for patients with a known or suspected anomaly, MRI can be helpful in screening fetuses with a family risk for brain abnormalities, as well as for assessment of fetal brain development [8,45-47]. If performed, this is ideally done at or after 22 weeks gestation [8], although an MRI performed between 18 to 22 weeks may be of value in certain clinical indications and settings [48].


Second and Third Trimester Screening for Fetal Anomaly. US Echocardiography Fetal The decision for the performance of fetal echocardiography, a subspecialized examination, is based on parental and fetal risk factors, as well as abnormal fetal cardiac screening examination. These risk factors include maternal genetic disease or risk, current medical conditions, and chemical exposures, as well as fetal factors such as known or suspected anomaly or cardiac abnormality [49-51].


Second and Third Trimester Screening for Fetal Anomaly. US Pregnant Uterus Transabdominal Detailed Scan High-risk patients should have a detailed scan, which is an indication-driven examination performed for a known or suspected fetal anatomic abnormality, known fetal growth disorder, genetic abnormality, or increased risk for a fetal anatomic or genetic abnormality [33,52]. Second and Third Trimester Screening for Fetal Anomaly


Second and Third Trimester Screening for Fetal Anomaly. US Pregnant Uterus Transabdominal Anatomy Scan There is no relevant literature to support the use of US pregnant uterus transabdominal anatomy scan for the second and third trimester screening for fetal anomaly in high-risk patients [33]. However, if the chorionic villous sampling, amniocentesis, or NIPT are normal, then the risk is diminished and a routine scan could be performed [8].


Second and Third Trimester Screening for Fetal Anomaly. Variant 3: Second and third trimester screening for abnormal finding on ultrasound: soft markers. Next imaging study. Soft markers are minor sonographic findings that have little or no pathologic significance, but may be associated with aneuploidy, most commonly trisomies 21 and 18, and other syndromes or pathologies. Soft markers have been used to recalculate the age-related trisomy risk and decrease the need for invasive testing when identified on the anatomy US examination [8,53,54].


Second and Third Trimester Screening for Fetal Anomaly. MRI Fetal Without and With IV Contrast There is no relevant literature to support the use of fetal MRI with and without IV contrast in the evaluation of fetuses with soft markers.


Second and Third Trimester Screening for Fetal Anomaly. MRI Fetal Without IV Contrast There is no relevant literature to support the use of fetal MRI without IV contrast in the evaluation of fetuses with soft markers.


Second and Third Trimester Screening for Fetal Anomaly. US Pregnant Uterus Transabdominal Follow-up If one or more required structures are not adequately demonstrated during the detailed fetal anatomic examination, if the study is considered incomplete, or if there is reason for follow-up of an anomaly identified on the screening or detailed examination, the patient may be brought back for a focused follow-up assessment [33]. Even if the fetus is euploid, follow-up US is recommended at 32 weeks for the following soft markers: pyelectasis, short humerus length, short femur length, and echogenic bowel [8,17,59,62,63].


Second and Third Trimester Screening for Fetal Anomaly. US Pregnant Uterus Transabdominal Detailed Scan If a soft marker is found on the anatomy scan, a detailed US examination can be performed at the same time to look for additional markers and anomalies, or may be scheduled for the near future. For soft markers that relate only to aneuploidy risk, such as echogenic intracardiac focus and choroid plexus cyst, a detailed scan is optional to be certain the finding is isolated. For other soft markers, such as renal pyelectasis, short humerus and femur, nuchal thickening, echogenic bowel, and short or absent nasal bone, a detailed scan is usually indicated [8,17,52,59,61]. Second and Third Trimester Screening for Fetal Anomaly


Second and Third Trimester Screening for Fetal Anomaly. MRI Fetal Without IV Contrast The International Society of Ultrasound in Obstetrics and Gynecology current guidelines recommend that fetal MRI is generally indicated following an US examination in which the information about the abnormality is incomplete [48]. Under these circumstances, MRI may provide important information that may confirm or complement the US findings and alter or modify patient management [79,84-88]. Fetal MRI is especially helpful for central nervous system anomalies, planning for prenatal and postnatal intervention, and for airway management in fetuses with neck masses [4,8,11]. Other indications for fetal MRI include evaluation of cranial, facial, thoracic, abdominal, retroperitoneal, and pelvic anomalies, as well as complications of monochorionic gestations [89].


Second and Third Trimester Screening for Fetal Anomaly. Although available data are still inconclusive, MRI for parental reassurance regarding the absence of associated pathologies in fetuses with apparently isolated conditions may be recommended in fetuses with the following sonographic findings: isolated ventriculomegaly, agenesis of the corpus callosum, absent cavum septi pellucidi, and cerebellar or vermian anomalies [48]. If fetal MRI is performed, this is ideally done at or after 22 weeks gestation [8], although an MRI performed between 18 to 22 weeks may be of value in certain clinical indications and settings [48].


Second and Third Trimester Screening for Fetal Anomaly. US Echocardiography Fetal The decision for the performance of fetal echocardiography, a subspecialized examination, is based on parental and fetal risk factors, as well as abnormal fetal cardiac screening examination. These risk factors include maternal genetic disease or risk, current medical conditions, and chemical exposures, as well as fetal factors such as known anomaly or cardiac abnormality [49-51].


Second and Third Trimester Screening for Fetal Anomaly. US Pregnant Uterus Transabdominal Follow-up If one or more required structures are not adequately demonstrated during the detailed fetal anatomic examination, if the study is considered incomplete, or there is reason for follow-up of an anomaly identified on the screening examination, the patient may be brought back for a focused assessment [33]. Additionally, repeat transabdominal US is also performed for growth, delivery, and postnatal planning/management in the setting of an identified anomaly if the pregnancy is continued.


Second and Third Trimester Screening for Fetal Anomaly. US Pregnant Uterus Transabdominal Detailed Scan If an anomaly is seen or suspected on a first trimester US or a second trimester routine US, then a detailed second trimester US (or third trimester detailed US if finding is detected later) is indicated, according to the AIUM Consensus Report on the Detailed Fetal Anatomic Ultrasound Examination [33,52].


Second and Third Trimester Screening for Fetal Anomaly. 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 Screening for Fetal Anomaly. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Imaging of Suspected Intracranial Hypotension PCAs. Introduction/Background The clinical syndrome of intracranial hypotension refers to the symptoms caused by cerebrospinal fluid (CSF) hypovolemia and is primarily characterized by postural headaches [1,2]. According to the International Classification of Headache Disorders, third edition, the low CSF pressure headache is typically orthostatic in nature, is caused by low CSF pressure (<6 cm H2O) or CSF leakage, and remits after normalization of CSF pressure or a successful sealing of the CSF leak [3]. The onset of symptoms may be spontaneous or secondary depending on a temporal relation to a presumed cause, such as a recent procedural dural puncture. Headache symptoms may be accompanied by additional symptomatology to include nausea, vomiting, neck pain, tinnitus, changes in hearing, and photophobia [4].


Imaging of Suspected Intracranial Hypotension PCAs. It is estimated that spontaneous intracranial hypotension (SIH) occurs with an incidence of approximately 5 per 100,000 individuals annually [5]. The true incidence of this condition may be higher, because SIH is thought to be both highly underdiagnosed and a misdiagnosed disorder [4,6-8]. Clinical risk factors for the development of SIH include spinal osteophytes that can perforate the dura, weakened ectatic dura/meningeal cysts as can be seen with collagen vascular disease, and a history of bariatric surgery in which it is postulated that rapid loss of epidural fat may weaken the dura and predispose to CSF leakage [4,9-12]. Secondary intracranial hypotension symptoms related to dural puncture are thought to occur with a frequency of approximately 2% to 8% of cases, with risk factors in part related to needle type and gauge used [13-15].


Imaging of Suspected Intracranial Hypotension PCAs. The pathophysiologic mechanism of headache symptoms and various neurological deficits in patients with intracranial hypotension is not well understood but likely multifactorial and may be attributed to 1) compensatory venodilitation, blood volume expansion, and dural sinus stretching as the body attempts to maintain a stable intracranial volume in response to decreased CSF volume; and 2) downward traction on the meninges, nerves, and brain parenchyma as the brain loses buoyancy and begins to sag in response to decreased CSF volume. The findings of venodilitation and brain sagging have well-defined imaging findings and have been shown to resolve along with clinical improvement of headache symptoms [16,17].


Imaging of Suspected Intracranial Hypotension PCAs. The 3 main causes of intracranial hypotension are CSF leakage through a dural defect, leaking meningeal diverticulum, and CSF-venous fistula [18-20]. It is important to note that in the upright position, intracranial hydrostatic pressure is slightly negative relative to atmosphere, whereas hydrostatic pressure in the spine is positive relative to atmosphere [21]. Consequently, the spine has been shown to represent the anatomical source of most symptomatic CSF leaks and venous fistulas, such that the imaging investigation of leak source should be directed primarily toward the spine and not intracranially [22].


Imaging of Suspected Intracranial Hypotension PCAs. Imaging plays a critical role in the diagnostic evaluation of intracranial hypotension. The goals of imaging are 2- fold: 1) to confirm the diagnosis of intracranial hypotension and 2) to localize the source of leak for targeted therapy such as epidural blood patch, percutaneous fibrin glue treatment, endovascular venous fistula embolization, and surgical dural repair or venous fistula ligation [23,24]. Intracranial imaging features suggestive of intracranial


Imaging of Suspected Intracranial Hypotension PCAs. aMayo Clinic Arizona, Phoenix, Arizona. bPanel Chair, Mallinckrodt Institute of Radiology, Saint Louis, Missouri. cThe Ohio State University Wexner Medical Center, Columbus, Ohio. dMontefiore Medical Center, Bronx, New York. eWashington University School of Medicine, Saint Louis, Missouri. fEmory University School of Medicine, Atlanta, Georgia; American Association of Neurological Surgeons/Congress of Neurological Surgeons. gHospital of the University of Pennsylvania, Philadelphia, Pennsylvania. hUniversity of Utah Health, Salt Lake City, Utah. iUniversity of Rochester Medical Center, Rochester, New York; American Academy of Neurology. jThomas Jefferson University Hospital, Philadelphia, Pennsylvania. kJacobi Medical Center, Bronx, New York. lBrigham & Women's Hospital, Boston, Massachusetts; Committee on Emergency Radiology-GSER. mUniversity of California San Francisco, San Francisco, California. nSchmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida; American College of Emergency Physicians. oUniversity of Cincinnati, Cincinnati, Ohio; Commission on Nuclear Medicine and Molecular Imaging. pSpecialty Chair, University of Iowa Hospitals and Clinics, Iowa City, Iowa. 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.


Imaging of Suspected Intracranial Hypotension PCAs. Reprint requests to: publications@acr.org


Imaging of Suspected Intracranial Hypotension PCAs. Imaging of Suspected Intracranial Hypotension hypotension include qualitative signs (engorgement of venous sinuses, pachymeningeal enhancement, midbrain descent, superficial siderosis, subdural hygroma or hematoma, and convex superior surface of the pituitary) and quantitative signs (pituitary height, pontomesencephalic angle, suprasellar cistern, prepontine cistern, midbrain descent, venous-hinge angle, mamillopontine angle, tonsillar descent, and area cavum veli interpositi) [4,16,25-27]. The cumulative presence of these intracranial findings has been shown to correlate with a likelihood of finding a spinal leak source [16]. The spinal imaging findings associated with SIH include direct evidence of CSF leakage via epidural fluid collections and CSF-venous fistula as well as secondary indirect signs of CSF leakage such as dilated epidural venous plexus, subdural hygromas, and dural enhancement [24,28-30]. It should be noted that CSF pressure can be normal in patients with SIH, and the absence of a low CSF pressure should not exclude this condition [31,32]. It also bears mentioning that the diagnosis of SIH is challenging, and in some cases SIH cannot be definitely diagnosed or excluded until a full diagnostic workup with invasive imaging (myelography) has been performed. In cases in which symptoms persist after a negative full imaging workup, the possibility of SIH mimicking pathologies such as positional orthostatic tachycardia syndrome, cervicogenic headaches, migraines, or new daily persistent headache syndromes should be considered [33].


Imaging of Suspected Intracranial Hypotension PCAs. Using the best available evidence, this document provides diagnostic imaging recommendations for intracranial hypotension across various clinical presentations. In cases in which conservative/medical management or a therapeutic procedural intervention may be a more appropriate first step over imaging, the evidence to support such practices is discussed in the variant narrative.


Imaging of Suspected Intracranial Hypotension PCAs. OR Discussion of Procedures by Variant Variant 1: Adult. Orthostatic headache from suspected intracranial hypotension, without recent spinal intervention that could cause CSF leakage. Initial imaging. This clinical scenario refers to a patient who demonstrates postural orthostatic headaches with or without additional secondary SIH symptoms. The absence of a recent spinal intervention such as a dural puncture is relevant because orthostatic headaches are known, usually self-limiting sequelae of such procedures that do not typically require an imaging workup [4,13]. Orthostatic headaches without a temporal relation to dural puncture usually require 2 initial imaging examinations: brain imaging to help confirm a suspected SIH diagnosis and spine imaging to assist in localizing a potential source of CSF leak [4].


Imaging of Suspected Intracranial Hypotension PCAs. CT Complete Spine With IV Contrast There is no relevant literature to support the use of CT complete spine with intravenous (IV) contrast in the initial imaging of suspected SIH.


Imaging of Suspected Intracranial Hypotension PCAs. CT Complete Spine Without and With IV Contrast There is no relevant literature to support the use of CT complete spine without and with IV contrast in the initial imaging of suspected SIH.


Imaging of Suspected Intracranial Hypotension PCAs. CT Complete Spine Without IV Contrast There is no relevant literature to support the use of CT complete spine without IV contrast in the initial imaging of suspected SIH.


Imaging of Suspected Intracranial Hypotension PCAs. CT Head Cisternography There is no relevant literature to support the use of CT head cisternography in the initial imaging of suspected SIH. The spine has been shown to represent the anatomical source of most symptomatic CSF leaks and venous fistulas,


Imaging of Suspected Intracranial Hypotension PCAs. Imaging of Suspected Intracranial Hypotension such that the imaging investigation of leak source should be directed primarily toward the spine and not intracranially [22].


Imaging of Suspected Intracranial Hypotension PCAs. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging of suspected SIH.


Imaging of Suspected Intracranial Hypotension PCAs. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of suspected SIH.


Imaging of Suspected Intracranial Hypotension PCAs. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast in the initial imaging of suspected SIH.


Imaging of Suspected Intracranial Hypotension PCAs. CT Myelography Complete Spine Although CT myelography complete spine can detect epidural contrast collections suggestive of dural defect or leaking meningeal diverticulum, MRI complete spine optimized with fluid sensitive sequences has been shown to detect epidural collections with equal sensitivity and is a preferred initial imaging option over CT myelography complete spine because it avoids the need for lumbar puncture [34-36].


Imaging of Suspected Intracranial Hypotension PCAs. CT Myelography Dynamic Complete Spine There is no relevant literature to support the use of dynamic CT myelography complete spine in the initial imaging of suspected SIH. Dynamic CT myelography plays an important role in the subsequent imaging workup of SIH after the initial brain and spine imaging [37,38]. Results from an initial spine MRI or conventional CT myelogram provide useful information on how a subsequent dynamic CT myelogram will be performed, such as prone positioning for suspected ventral dural defect or decubitus positioning for suspected leaking meningeal diverticulum or CSF-venous fistula [24,37-39]. Dynamic CT myelography involves an initial scan followed by delayed phase scans in immediate succession and, when performed in the decubitus position, may require 2 separate contrast injections due to the transient temporal characteristics associated with CSF-venous fistula visualization as well as limitations in contrast dosing [40-44].


Imaging of Suspected Intracranial Hypotension PCAs. DTPA Cisternography Although diethylenetriamine pentaacetate (DTPA) cisternography can detect epidural collections suggestive of dural defect or leaking meningeal diverticulum, MRI complete spine optimized with fluid sensitive sequences is typically the preferred initial imaging option over DTPA cisternography complete spine because it avoids the need for lumbar puncture and has superior spatial resolution for lesion localization [45,46].


Imaging of Suspected Intracranial Hypotension PCAs. MR Myelography Complete Spine There is no relevant literature to support the use of MR myelography complete spine in the initial imaging of suspected SIH. An MR myelogram with intrathecal gadolinium administration has been used in several studies as a subsequent follow-up imaging examination after initial spine imaging to increase sensitivity for the detection of slow leaking dural and meningeal diverticular defects [47-49]. Some limited evidence suggests a potential role for MR myelography in the detection of CSF-venous fistulas [50]. It should be noted that intrathecal use of gadolinium is currently off label. Although studies have suggested that intrathecal gadolinium can be administered safely in small doses, the safety profile of such imaging is not formally approved for such use, and special dosing caution is required to avoid potential of gadolinium induced neurotoxicity [51].


Imaging of Suspected Intracranial Hypotension PCAs. MRI Complete Spine With IV Contrast There is no relevant literature to support the use of MRI complete spine with IV contrast in the initial imaging of suspected SIH.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Complete Spine Without and With IV Contrast MRI complete spine without and with IV contrast can be useful in the initial evaluation of suspected SIH. The noncontrast component of this examination optimized with fluid sensitive sequences is most useful, particularly when performed with 3-D T2-weighted fat saturated sequences, which increases sensitivity for detecting fluid collections outside of the thecal sac [52]. It can detect with a high degree of accuracy the presence of epidural fluid collections and meningeal diverticula that can inform positioning and regions of interest for subsequent CSF leak localization imaging examinations, such as dynamic CT myelogram complete spine and digital subtraction myelography complete spine [25,34-36]. The contrast component of this examination may demonstrate dural


Imaging of Suspected Intracranial Hypotension PCAs. Imaging of Suspected Intracranial Hypotension


Imaging of Suspected Intracranial Hypotension PCAs. enhancement and engorged epidural venous plexus, which are also imaging features that support a diagnosis of SIH [28,29].


Imaging of Suspected Intracranial Hypotension PCAs. MRI Complete Spine Without IV Contrast MRI complete spine without IV contrast optimized with fluid sensitive sequences is most useful in the initial evaluation of suspected SIH, particularly when performed with 3-D T2-weighted fat saturated sequences, which increases sensitivity for detecting fluid collections outside of the thecal sac [52]. This examination can detect with a high degree of accuracy the presence of epidural fluid collections and meningeal diverticula that can inform positioning and regions of interest for subsequent CSF leak localization imaging examinations, such as dynamic CT myelogram complete spine and digital subtraction myelography complete spine [25,34-36].


Imaging of Suspected Intracranial Hypotension PCAs. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the initial imaging of suspected SIH.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Head Without and With IV Contrast MRI head without and with IV contrast is most useful in the initial evaluation of suspected SIH. Suggestive imaging features of SIH are best visualized on MRI head without and with IV contrast and include qualitative signs (engorgement of venous sinuses, pachymeningeal enhancement, midbrain descent, superficial siderosis, subdural hygroma or hematoma, and convex superior surface of the pituitary) and quantitative signs (pituitary height, pontomesencephalic angle, suprasellar cistern, prepontine cistern, midbrain descent, venous-hinge angle, mamillopontine angle, tonsillar descent, and area cavum veli interpositi) [16,25,26]. The cumulative presence of these intracranial findings has been shown to correlate with the likelihood of finding a spinal leak source [16].


Imaging of Suspected Intracranial Hypotension PCAs. MRI Head Without IV Contrast MRI head without IV contrast can be useful in the initial evaluation of suspected SIH. Although imaging features of suspected SIH are best visualized on MRI head without and with IV contrast, some imaging features such as midbrain descent, superficial siderosis, subdural hygroma or hematoma, convex superior surface of the pituitary, pituitary height, pontomesencephalic angle, suprasellar cistern, prepontine cistern, midbrain descent, venous-hinge angle, mamillopontine angle, tonsillar descent, and area cavum veli interpositi may be evaluated on noncontrast MRI sequences [16,25,26]. The cumulative presence of these intracranial findings has been shown to correlate with likelihood of finding a spinal leak source [16].


Imaging of Suspected Intracranial Hypotension PCAs. Radiographic Myelography Digital Subtraction Complete Spine There is no relevant literature to support the use of dynamic digital subtraction myelography in the initial imaging of suspected SIH. Dynamic digital subtraction myelography plays an important role in the subsequent imaging workup of SIH after initial brain and spine imaging [53]. Results from an initial spine MRI or conventional CT myelogram provide useful information on how a subsequent dynamic digital subtraction myelogram will be performed, such as prone positioning for suspected ventral dural defect or decubitus positioning for suspected leaking meningeal diverticulum or CSF-venous fistula [24,53,54]. Dynamic digital subtraction myelography involves continuous real-time fluoroscopic x-ray imaging of the entire spine or of a focused region of the spine where there is suspicion for CSF leak. When performed in the decubitus position, 2 separate contrast injections may be required due to the transient temporal characteristics associated with CSF-venous fistula visualization as well as limitations in contrast dosing [40-44].


Imaging of Suspected Intracranial Hypotension PCAs. Variant 2: Adult. Orthostatic headache from suspected intracranial hypotension within 72 hours of dural puncture or other spinal intervention that could cause CSF leakage. Initial imaging. Leakage of CSF following a dural puncture may be of sufficient volume to elicit symptoms of intracranial hypotension. Postdural puncture headaches occur with an estimated frequency of 2% to 8% [13-15]. Risk factors for postdural puncture headaches include the use of a larger gauge needle, multiple attempts at dural puncture, the use of a cutting needle versus pencil point tip needle, needle orientation perpendicular rather than parallel to spine longitudinal axis (when using a cutting needle), and dural puncture in the sitting position as opposed to lateral decubitus positioning [55-58]. Imaging is not typically indicated in this clinical setting because postdural puncture headaches are typically self-limited, with most symptoms fully resolving within 1 week without any treatment [13]. The initial management of postdural puncture headaches is conservative medical management, with consideration of epidural blood patch if symptoms are severe or not beginning to resolve by 2 to 3 days postdural puncture [59- 61].


Imaging of Suspected Intracranial Hypotension PCAs. Imaging of Suspected Intracranial Hypotension CT Complete Spine With IV Contrast There is no relevant literature to support the use of CT complete spine with IV contrast in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. CT Complete Spine Without and With IV Contrast There is no relevant literature to support the use of CT complete spine without and with IV contrast in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. CT Complete Spine Without IV Contrast There is no relevant literature to support the use of CT complete spine without IV contrast in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. CT Head Cisternography There is no relevant literature to support the use of CT head cisternography in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. CT Myelography Complete Spine There is no relevant literature to support the use of CT myelography complete spine in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. CT Myelography Dynamic Complete Spine There is no relevant literature to support the use of dynamic CT myelography complete spine in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. DTPA Cisternography There is no relevant literature to support the use of DTPA cisternography in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. MR Myelography Complete Spine There is no relevant literature to support the use of MR myelography complete spine in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Complete Spine With IV Contrast There is no relevant literature to support the use of MRI complete spine with IV contrast in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Complete Spine Without and With IV Contrast There is no relevant literature to support the use of MRI complete spine without and with IV contrast in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Complete Spine Without IV Contrast There is no relevant literature to support the use of MRI complete spine without IV contrast in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. Imaging of Suspected Intracranial Hypotension MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. Radiographic Myelography Digital Subtraction Complete Spine There is no relevant literature to support the use of dynamic digital subtraction myelography complete spine in the initial imaging of suspected intracranial hypotension within 72 hours of dural puncture.


Imaging of Suspected Intracranial Hypotension PCAs. Variant 3: Adult. Orthostatic headache from suspected intracranial hypotension without improvement post 72 hours of dural puncture or other spinal intervention that could cause CSF leakage. Initial imaging. This clinical variant refers to a patient with orthostatic headache in temporal relation to a dural puncture that is not improving following a trial of conservative management. Imaging is not usually warranted in this clinical scenario, because the next management step for such patients typically involves an epidural blood patch procedure directed at the level of dural puncture [59-61].


Imaging of Suspected Intracranial Hypotension PCAs. CT Complete Spine With IV Contrast There is no relevant literature to support the use of CT complete spine with IV contrast in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. CT Complete Spine Without and With IV Contrast There is no relevant literature to support the use of CT complete spine without and with IV contrast in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. CT Complete Spine Without IV Contrast There is no relevant literature to support the use of CT complete spine without IV contrast in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. CT Head Cisternography There is no relevant literature to support the use of CT head cisternography in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. CT Myelography Complete Spine There is no relevant literature to support the use of CT myelography complete spine in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. CT Myelography Dynamic Complete Spine There is no relevant literature to support the use of dynamic CT myelography complete spine in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. Imaging of Suspected Intracranial Hypotension DTPA Cisternography There is no relevant literature to support the use of DTPA cisternography in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. MR Myelography complete spine There is no relevant literature to support the use of MR myelography complete spine in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Complete Spine With IV Contrast There is no relevant literature to support the use of MRI complete spine with IV contrast in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Complete Spine Without and With IV Contrast There is no relevant literature to support the use of MRI complete spine without and with IV contrast in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Complete Spine Without IV Contrast There is no relevant literature to support the use of MRI complete spine without IV contrast in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. Radiographic Myelography Digital Subtraction Complete Spine There is no relevant literature to support the use of dynamic digital subtraction myelography complete spine in the initial imaging of suspected intracranial hypotension without improvement after 72 hours of dural puncture or other spinal intervention that could cause CSF leakage.


Imaging of Suspected Intracranial Hypotension PCAs. Variant 4: Adult. Obtundation with initial brain imaging features of suspected intracranial hypotension. Next imaging study. This clinical scenario represents a severe clinical manifestation of SIH, which may represent sequela of more severe mechanical traction forces from brain sagging in the setting of CSF hypovolemia [62,63]. There are some limited reports of successful acute management of these critically ill patients with intrathecal saline infusions via lumbar drains, which may serve as a temporizing measure to raise CSF pressure and reverse obtundation [64-67]. The subsequent management of such patients is otherwise similar to patients with SIH without impaired consciousness and focuses on spine imaging to localize a source of leak that may be targeted for definitive treatment [24].


Imaging of Suspected Intracranial Hypotension PCAs. CT Complete Spine With IV Contrast There is no relevant literature to support CT complete spine with IV contrast as a next imaging study in the clinical setting of obtundation with initial brain imaging features of suspected intracranial hypotension.


Imaging of Suspected Intracranial Hypotension PCAs. Imaging of Suspected Intracranial Hypotension CT Complete Spine Without and With IV Contrast There is no relevant literature to support CT complete spine without and with IV contrast as a next imaging study in the clinical setting of obtundation with initial brain imaging features of suspected intracranial hypotension.


Imaging of Suspected Intracranial Hypotension PCAs. CT Complete Spine Without IV Contrast There is no relevant literature to support CT complete spine without IV contrast as a next imaging study in the clinical setting of obtundation with initial brain imaging features of suspected intracranial hypotension.


Imaging of Suspected Intracranial Hypotension PCAs. CT Myelography Complete Spine Although CT myelography complete spine can detect epidural contrast collections suggestive of dural defect or leaking meningeal diverticulum, MRI complete spine optimized with fluid sensitive sequences has been shown to detect epidural collections with equal sensitivity and is a preferred initial imaging option over CT myelography complete spine because it avoids the need for lumbar puncture [34,35].


Imaging of Suspected Intracranial Hypotension PCAs. CT Myelography Dynamic Complete Spine There is no relevant literature to support the use of dynamic CT myelography complete spine as a next imaging study in the clinical setting of obtundation with initial brain imaging features of suspected intracranial hypotension. Dynamic CT myelography plays an important role in the subsequent imaging workup of SIH after initial brain and spine imaging [37,38]. Results from an initial spine MRI or conventional CT myelogram provide useful information on how a subsequent dynamic CT myelogram will be performed, such as prone positioning for suspected ventral dural defect or decubitus positioning for suspected leaking meningeal diverticulum or CSF-venous fistula [24,37- 39]. Dynamic CT myelography involves an initial scan followed by delayed phase scans in immediate succession and, when performed in the decubitus position, may require 2 separate contrast injections due to the transient temporal characteristics associated with CSF-venous fistula visualization as well as limitations in contrast dosing [40-44].


Imaging of Suspected Intracranial Hypotension PCAs. DTPA Cisternography Although DTPA cisternography can detect epidural collections suggestive of dural defect or leaking meningeal diverticulum, MRI complete spine optimized with fluid sensitive sequences is typically the preferred initial imaging option over DTPA cisternography complete spine because it avoids the need for lumbar puncture and has superior spatial resolution for lesion localization [45,46].


Imaging of Suspected Intracranial Hypotension PCAs. MR Myelography Complete Spine There is no relevant literature to support the use of MR myelography complete spine as a next imaging study in the clinical setting of obtundation with initial brain imaging features of suspected intracranial hypotension. An MR myelogram with intrathecal gadolinium administration has been used in several studies as a subsequent follow-up imaging examination after initial spine imaging to increase the sensitivity for detection of slow leaking dural and meningeal diverticular defects [47-49]. Some limited evidence suggests a potential role for MR myelography in the detection of CSF-venous fistulas [50]. It should be noted that intrathecal use of gadolinium is currently off label. Although studies have suggested that intrathecal gadolinium can be administered safely in small doses, the safety profile of such imaging is not formally approved for such use, and special dosing caution is required to avoid potential of gadolinium induced neurotoxicity [51].


Imaging of Suspected Intracranial Hypotension PCAs. MRI Complete Spine With IV Contrast There is no relevant literature to support the use of MRI complete spine with IV contrast as a next imaging study in the clinical setting of obtundation with initial brain imaging features of suspected intracranial hypotension.


Imaging of Suspected Intracranial Hypotension PCAs. MRI Complete Spine Without and With IV Contrast MRI complete spine without and with IV contrast can be useful as a next imaging study in the clinical setting of obtundation with initial brain imaging features of suspected intracranial hypotension. The noncontrast component of this examination optimized with fluid sensitive sequences is most useful, particularly when performed with 3-D T2-weighted fat saturated sequences, which increases the sensitivity for detecting fluid collections outside of the thecal sac [52]. It can detect with a high degree of accuracy the presence of epidural fluid collections and meningeal diverticula that can inform positioning and regions of interest for subsequent CSF leak localization imaging examinations, such as dynamic CT myelogram complete spine and digital subtraction myelography complete spine [25,34-36]. The contrast component of this examination may demonstrate dural enhancement and engorged epidural venous plexus, which are also imaging features that support a diagnosis of SIH [28,29].


Imaging of Suspected Intracranial Hypotension PCAs. Imaging of Suspected Intracranial Hypotension MRI Complete Spine Without IV Contrast MRI complete spine without IV contrast optimized with fluid sensitive sequences is most useful as a next imaging study in the clinical setting of obtundation with initial brain imaging features of suspected intracranial hypotension, particularly when performed with 3-D T2-weighted fat saturated sequences, which increases sensitivity for detecting fluid collections outside of the thecal sac [52]. This examination can detect with a high degree of accuracy the presence of epidural fluid collections and meningeal diverticula that can inform positioning and regions of interest for subsequent CSF leak localization imaging examinations, such as dynamic CT myelogram complete spine and digital subtraction myelography complete spine [25,34-36].


Imaging of Suspected Intracranial Hypotension PCAs. Radiographic Myelography Digital Subtraction Complete Spine There is no relevant literature to support the use of dynamic digital subtraction myelogram complete spine as a next imaging study in the clinical setting of obtundation with initial brain imaging features of suspected intracranial hypotension. Dynamic digital subtraction myelography plays an important role in the subsequent imaging workup of SIH after initial brain and spine imaging [53]. Results from an initial spine MRI or conventional CT myelogram provide useful information on how a subsequent dynamic digital subtraction myelogram will be performed, such as prone positioning for suspected ventral dural defect or decubitus positioning for suspected leaking meningeal diverticulum or CSF-venous fistula [24,53,54]. Dynamic digital subtraction myelography involves continuous real- time fluoroscopic x-ray imaging of the entire spine or of a focused region of the spine where there is suspicion for CSF leak. When performed in the decubitus position, 2 separate contrast injections may be required due to the transient temporal characteristics associated with CSF-venous fistula visualization as well as limitations in contrast dosing [40-44].


Imaging of Suspected Intracranial Hypotension PCAs. Variant 5: Adult. Chronic daily headache from suspected intracranial hypotension with negative initial brain and spine imaging, but with history and clinical examination suggesting CSF leakage. Next imaging study. Negative initial imaging should not preclude continued diagnostic workup in a patient with clinically suspected SIH [4,53]. Approximately 20% of initial brain MRIs and 46% to 67% of initial spine imaging in patients with clinically suspected SIH may have normal results [4]. Of note, CSF-venous fistulas and slow meningeal diverticular leaks are often subtle imaging findings that may not be readily detectable using conventional imaging techniques with limited temporal resolution and may require follow-up imaging with more advanced imaging procedures to definitely identify or exclude a more subtle spinal CSF leak source [7,53,68-70].


Imaging of Suspected Intracranial Hypotension PCAs. CT Head Cisternography There is no relevant literature to support the use of CT head cisternography in the subsequent imaging of suspected SIH. The spine has been shown to represent the anatomical source of most symptomatic CSF leaks and venous fistulas, such that the imaging investigation of leak source should be directed primarily toward the spine and not intracranially [22].


Imaging of Suspected Intracranial Hypotension PCAs. CT Myelography Dynamic Complete Spine Dynamic CT myelography plays an important role in the subsequent imaging workup of SIH after initial brain and spine imaging [37,38]. Results from an initial spine MRI or conventional CT myelogram provide useful information on how a subsequent dynamic CT myelogram will be performed, such as prone positioning for suspected ventral dural defect or decubitus positioning for suspected leaking meningeal diverticulum or CSF-venous fistula [24,37- 39]. Dynamic CT myelography involves an initial scan followed by delayed phase scans in immediate succession and, when performed in the decubitus position, may require 2 separate contrast injections due to the transient temporal characteristics associated with CSF-venous fistula visualization as well as limitations in contrast dosing [40-44].


Imaging of Suspected Intracranial Hypotension PCAs. DTPA Cisternography DTPA cisternography of the spine can detect CSF leaks with similar accuracy to conventional CT myelography [45]. Due to its limited spatial resolution, a positive DTPA cisternogram may require further investigation with subsequent dynamic CT myelography or dynamic digital subtraction myelography to definitively localize leak for treatment planning [45,46].


Imaging of Suspected Intracranial Hypotension PCAs. MR Myelography Complete Spine An MR myelogram with intrathecal gadolinium administration has been used in several studies to increase sensitivity for the detection of slow leaking dural and meningeal diverticular defects [47-49]. Some limited evidence suggests a potential role for MR myelography in the detection of CSF-venous fistulas [50]. It should be noted that intrathecal use of gadolinium is currently off label. Although studies have suggested that intrathecal gadolinium can


Imaging of Suspected Intracranial Hypotension PCAs. Imaging of Suspected Intracranial Hypotension be administered safely in small doses, the safety profile of such imaging is not formally approved for such use, and special dosing caution is required to avoid potential of gadolinium induced neurotoxicity [51].


Imaging of Suspected Intracranial Hypotension PCAs. Radiographic Myelography Digital Subtraction Complete Spine Dynamic digital subtraction myelography plays an important role in the subsequent imaging workup of SIH after initial brain and spine imaging [53]. Results from an initial spine MRI or conventional CT myelogram provide useful information on how a subsequent dynamic digital subtraction myelogram will be performed, such as prone positioning for suspected ventral dural defect or decubitus positioning for suspected leaking meningeal diverticulum or CSF-venous fistula [24,53,54]. Dynamic digital subtraction myelography involves continuous real-time fluoroscopic x-ray imaging of the entire spine or of a focused region of the spine where there is suspicion for CSF leak. When performed in the decubitus position, 2 separate contrast injections may be required due to the transient temporal characteristics associated with CSF-venous fistula visualization as well as limitations in contrast dosing [40-44].


Imaging of Suspected Intracranial Hypotension PCAs. Imaging of Suspected Intracranial Hypotension 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.


Imaging of Suspected Intracranial Hypotension PCAs. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Imaging of Suspected Intracranial Hypotension PCAs. 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


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. Current approaches to patients with penetrating neck injuries result from clinical evaluation and the findings of hard versus soft signs. Hard signs of vascular or aerodigestive injury include active hemorrhage, pulsatile or expanding hematoma, bruit or thrill in the region of the wound, hemodynamic instability, unilateral upper- extremity pulse deficit, massive hemoptysis or hematemesis, air bubbling in the wound, and airway compromise. These hard signs of injury are associated with an unstable or a potentially unstable patient and often mandate immediate operative evaluation and treatment without preoperative imaging. Symptoms related to cerebral ischemia are also hard signs of penetrating injury, but these patients may be stable enough to benefit from first performing imaging studies. Imaging of the brain in addition to the head and neck vasculature may be used to determine optimal surgical, endovascular, or medical therapy. Soft signs of vascular and aerodigestive injury include nonpulsatile or nonexpanding hematoma, venous oozing, dysphagia, dysphonia, and subcutaneous emphysema [6,7]. These commonly result in further evaluation, typically with imaging.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. Overview of Imaging Modalities CTA dominates the imaging landscape when it comes to the initial evaluation of patients with penetrating neck trauma who do not require immediate surgical exploration [2,6,8,11]. In early comparisons with catheter angiography, CTA demonstrated high sensitivity and specificity [5,11-16]. This held true in a prospective study in 2012 [5] for detecting vascular and aerodigestive injury by CTA, where sensitivity was 100% and specificity was 97.5%. Early adoption of CTA in the initial evaluation of patients with penetrating injuries to the neck led to a


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. 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.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. *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,


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. Department of Defense, or United States Government. Reprint requests to: publications@acr.org


Penetrating Neck Injury PCAs

Penetrating Neck Injury

Penetrating Neck Injury PCAs. Penetrating Neck Injury


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. decrease in overall neck explorations and negative neck explorations as well as the use of catheter angiography and esophagography [17]. A recent retrospective study [18] reviewed the selective nonoperative management of patients with clinical hard signs. Of patients with hard signs who were hemodynamically stable and had a stable airway, 74% who received a CTA were able to avoid surgical neck exploration.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. In patients for whom the risk of allergic reaction to iodinated contrast is high or unknown, premedication may be appropriate per ACR recommendations [19]. If there is a high risk for contrast reaction or if iodinated contrast cannot be given, unenhanced computed tomography (CT) imaging of the neck may be performed, but with the understanding the vasculature may be underevaluated.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. Ultrasound (US) is limited in its use in patients with penetrating neck injury, given the effect of overlying or adjacent soft-tissue injury. It may be complicated by a cervical collar or overlying skin dressings, provides limited evaluation of surrounding structures, and is of limited use in zone I and III injuries [4,13,14,22,23]. Early studies comparing US and catheter-based angiography demonstrated a sensitivity of 91%, a specificity of 98% to 100%, a positive predictive value of 100%, and a negative predictive value of 99% for patients with clinical soft signs imaged by US [24,25].


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. Fluoroscopic upper gastrointestinal tract examination has its role in the evaluation of penetrating neck injuries but is typically used as a problem-solving modality [2,6,8]. Barium swallow, preferably with water-soluble contrast, may miss significant oropharyngeal and hypopharyngeal injuries, although this imaging examination will typically detect esophageal injuries [27].


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. As arterial injury occurs in a proportion of patients with penetrating neck injury, one must be cognizant of the possibility of end-organ injury, particularly to the brain. Although not directly related to imaging of the neck in penetrating injuries, imaging of the brain and cerebral vasculature may be considered where cervical vascular injury is determined either by clinical examination, imaging, or surgery.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. Discussion of Procedures by Variant Variant 1: Penetrating neck injury. Clinical soft injury signs. Radiography Radiographs are ubiquitous in radiology and in some practices may be employed in the initial evaluation of acute trauma patients [28]. In the initial evaluation in the trauma bay, radiographs of the neck may demonstrate radio- opaque foreign bodies, soft-tissue swelling, airway competency, fractures, and subcutaneous emphysema. With the exception of patients exhibiting clear hard signs necessitating immediate surgical intervention, the initial radiographs are generally followed by a more detailed CT or CTA evaluation.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. CTA After the clinical determination is made regarding the need for immediate surgical exploration (eg, presence of hard versus soft signs), CTA is considered the first-line imaging evaluation, replacing catheter angiography as the preferred modality. Multiple studies have shown CTA to have high sensitivity, in the range of 90% to 100%; specificity ranging from 98.6% to 100%; a positive predictive value of 92.8% to 100%; and a negative predictive value of 98% to 100% [5,12,14] for evaluating vascular injury. In addition to identifying vascular injury, CTA simultaneously identifies extravascular soft-tissue and aerodigestive injuries with a sensitivity of 100% and a specificity ranging from 93.5% to 97.5% [2,5,6,8,12-14,17,29].


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. CT esophagography has been described for diagnosing suspected upper-digestive-tract injuries in the trauma setting. There are limited data on this imaging modality, which can be performed either in conjunction with the


Penetrating Neck Injury PCAs

Penetrating Neck Injury


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. Arteriography, MRI, MRA, US, and Esophagram Although catheter angiography, MRI, MRA, US, and fluoroscopic studies could be used in the initial evaluation of penetrating neck injury, these are typically relegated to problem solving for specific issues in contemporary trauma workups.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. Variant 2: Penetrating neck injury. Normal or equivocal CTA. Concern for vascular injury. Arteriography Catheter angiography was traditionally used in the evaluation of zones I and III but now is considered primarily in the evaluation of patients with a normal or equivocal CTA with a concerning penetrating foreign body trajectory [6,8] or when endovascular therapy is to be performed [1]. Catheter angiography may be performed in follow-up to equivocal CTA examinations, especially when a clinically significant vascular injury cannot be reliably excluded. A limitation of CTA is the potential for streak artifact from retained metallic foreign bodies; in this instance, digital subtraction catheter angiography may be more sensitive and appropriate for vascular evaluation [20,21].


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. US Studies in the 1990s demonstrated a high sensitivity and specificity, as well as positive and negative predictive values, of US in patients with penetrating injuries to the neck [24,25,31]. In considering the strengths of US evaluation versus the limitations as discussed, in only very specific circumstances may US provide additional diagnostic insight. For overall structural and functional assessment in the initial evaluation period, arteriography remains the preferred modality.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. MRA MRA may be feasible in the clinically stable patient for the evaluation of vascular injuries, although limitations such as potential retained foreign bodies and length of the examination may preclude its use [4,13,15,23]. In select and appropriate patients, MRI techniques, including 2-D and 3-D time-of-flight, contrast-enhanced time-resolved, and phase-contrast techniques, are available to evaluate the neck vasculature [32]. The 2-D and 3-D time-of-flight techniques do not require contrast for their technique.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. Variant 3: Penetrating neck injury. Normal or equivocal CTA. Concern for aerodigestive injury. Barium Swallow Various algorithms are present in practice for the use of esophagrams in the evaluation of aerodigestive injury in the patient with penetrating neck injury. These algorithms vary depending on factors such as whether or not the patient is symptomatic, the degree of clinical concern, the outcome of the initial CT or CTA, and the mechanism of injury [2,6,8,11]. Ahmed et al [27] argue that contrast fluoroscopic studies should not be used in the evaluation of oropharyngeal and hypopharyngeal injuries given that water-soluble and thin barium examinations missed 13 of 13 injuries in this area, compared with video endoscopy performed at the bedside. Water-soluble contrast is preferred, because there is the risk of extraluminal contrast extravasation. Panendoscopy with laryngoscopy, bronchoscopy, and esophagoscopy (flexible and rigid) is the gold standard to rule out oropharyngeal, hypopharyngeal, laryngotracheal, and esophageal injuries.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. MRI Overall, CT or CTA is preferred when evaluating for acute osseous and soft-tissue cervical injuries. MRI, in particular fat-suppressed T2-weighted imaging, is more sensitive for assessing potential cartilaginous and fibrous injuries but is relegated to specific problem-solving cases and is not routinely performed [26]. Standard MRI sequences to include short tau inversion recovery and T2, as well as gadolinium-enhanced T1 with fat saturation, may help further define the extent of injury of the soft tissues. In patients with penetrating neck injuries with clinical soft injury signs and in patients with hard signs of injury who do not require immediate surgical exploration, CTA of the neck is the preferred imaging procedure to evaluate the extent of injury.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. When there remains clinical concern for vascular injury despite a normal or equivocal CTA of the neck, catheter-based arteriography is useful for further evaluation. The benefit of arteriography is the ability to perform, in tandem, an endovascular procedure if needed. If there remains a concern for aerodigestive injury despite a normal or equivocal CTA of the neck, an x-ray single contrast esophagram may be considered, but it should be used in conjunction with direct visualization techniques.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. Although there are references that report on studies with design limitations, 3 well-designed or good-quality studies provide good evidence.


Penetrating Neck Injury PCAs

Penetrating Neck Injury PCAs. Supporting Documents For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Imaging of the Axilla

Imaging of the Axilla. Introduction/Background Unilateral or bilateral palpable or clinically suspicious axillary mass(es) have a broad differential diagnosis, including inflammatory, infectious, vascular, and malignant etiologies [1]. In most cases, an axillary mass confirmed on imaging is either normal tissue or of lymphoid or mammary origin. With the increased use of ultrasound (US) as a screening tool and as more advanced cross-sectional imaging detects incidental nonpalpable and clinically occult axillary findings, further evaluation with biopsy is often necessary to obtain a definitive diagnosis.


Imaging of the Axilla

Imaging of the Axilla. The clinically negative axilla is defined having no palpable nodes on physical examination [6]. If the clinical physical examination or imaging test(s) reveal a suspicious finding, then further investigation may involve US and breast MRI. If positive, percutaneous biopsy is often performed. The National Comprehensive Cancer Network (NCCN) guidelines do refer to the use of axillary US or MRI with possible biopsy to determine if there is ipsilateral axillary lymph node involvement in operable breast cancer patients prior to preoperative systemic therapy [7]. Several imaging modalities (mammography, tomosynthesis, US, CT, fluorine-18-2-fluoro-2-deoxy-D-glucose [FDG]-PET/CT, MRI) can visualize the axillary nodes and evaluate the size and morphology. In 2014, the American Society of Breast Surgeons published a consensus guideline on the management of the axilla in which SLNB has replaced ALND for clinically node-negative invasive breast cancer patients [6]. It is desirable to identify those patients who can safely receive SLNB and those who we can potentially omit SLNB. However, there is no standard radiologic imaging test for this purpose.


Imaging of the Axilla

Imaging of the Axilla. aThe University of Texas MD Anderson Cancer Center, Houston, Texas. bPanel Chair, Boston University School of Medicine, Boston, Massachusetts. cPanel Vice-Chair, New York University School of Medicine, New York, New York. dStanford University Medical Center, Stanford, California; Society of Surgical Oncology. eAlpert Medical School of Brown University, Providence, Rhode Island. fSmilow Cancer Hospital, Yale Cancer Center, New Haven, Connecticut; American College of Surgeons. gUniversity of California San Francisco, San Francisco, California. hSutter Medical Group and Sutter Cancer Center, Roseville, California. iUT Southwestern Medical Center, Dallas, Texas; American Society of Clinical Oncology. jEmory University Hospital, Atlanta, Georgia. kBoston Medical Center, Boston, Massachusetts, Primary care physician. lSanford Health of Northern Minnesota, Bemidji, Minnesota. mUniversity of Washington, Seattle, Washington. nMayo Clinic, Phoenix, Arizona. oPerelman School of Medicine of the University of Pennsylvania, Philadelphia, Pennsylvania. pSpecialty Chair, NYU Clinical Cancer Center, New York, New York.


Imaging of the Axilla

Imaging of the Axilla. 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.


Imaging of the Axilla

Imaging of the Axilla. Reprint requests to: publications@acr.org