Incidentally Detected Indeterminate Pulmonary Nodule PCAs. There are advantages of using CT as the first step in the characterization of pulmonary nodules detected on radio- graphs. Overlapping structures that might be causing pseudonodules are removed. Certain nodule characteristics suggestive of benign etiology are better appreciated by CT and can avoid additional workup. For example, diffuse, central, laminated, or popcorn calcifications patterns are predictors of benign etiology (odds ratio [OR] = 0.07-0.20) [28]. Macroscopic fat is another indicator of benign etiology typical of hamartomas, which cannot be appreciated on radiographs. The mean attenuation value of indeterminate benign and malignant nodules on unenhanced CT is not significantly different and therefore not useful in their differentiation. However, multiple imaging features that increase the risk of malignancy are best characterized on CT, including nodule size, morphology, location, multi- plicity, or the presence of emphysema or fibrosis. Unsuspected associated processes such as lymphadenopathy can sometimes be detected on CT, and CT can help with planning next steps such as biopsy when indicated [2].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. CT Chest Without and With IV Contrast There is no relevant literature to support the use of dynamic contrast-enhanced CT in the initial evaluation of incidentally detected indeterminate pulmonary nodules on chest radiographs. IV contrast is not required to identify or initially characterize pulmonary nodules on CT [27].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. CT Chest With IV Contrast There is no relevant literature to support the use of contrast-enhanced CT in the initial evaluation of incidentally detected indeterminate pulmonary nodules on chest radiographs. IV contrast is not required to identify or initially characterize pulmonary nodules on CT [27]. Cancer staging, an incidental mass workup, and nodules with associated lymphadenopathy fall outside of the scope of this document.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. FDG-PET/CT Whole Body There is no relevant literature to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT in the initial evaluation of incidentally detected indeterminate pulmonary nodules on chest radiographs.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. FDG-PET/MRI Whole Body There is no relevant literature to support the use of FDG-PET/MRI in the evaluation of incidentally detected indeterminate pulmonary nodules.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Image-Guided Transthoracic Needle Biopsy There is no relevant literature to support the use of image-guided transthoracic needle biopsy (TNB) in the initial evaluation of incidentally detected indeterminate pulmonary nodules on chest radiographs.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest in the initial evaluation of incidentally detected indeterminate pulmonary nodules on chest radiographs.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Incidentally Detected Indeterminate Pulmonary Nodule MRI Chest Without and With IV Contrast There is no relevant literature to support the use of dynamic MRI chest in the initial evaluation of incidentally detected indeterminate pulmonary nodules on chest radiographs.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Radiography Chest About 20% of suspected nodules on chest radiographs prove to be pseudonodules. These are generally caused by rib fractures, skin lesions, anatomic variants, or overlapping structures [25]. Repeat radiographs with nipple markers, chest fluoroscopy, oblique chest views, and dual-energy subtraction radiography have been described to help distinguish between a pulmonary nodule and a pseudonodule to avoid additional or invasive workup [25]. There is insufficient literature to support their widespread use, and validation studies are needed to measure the effectiveness of newer techniques like dual-energy subtraction. Despite the lack of sufficient literature supporting these methods, the panel consensus was that a repeat chest radiograph is a common practice and may be a useful next step when a pseudonodule is suspected on a radiograph.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. When encountering indeterminate solid nodules on chest radiograph, ACCP guidelines recommend thin-section chest CT as the next step unless prior imaging is available to prove stability over 2 years (grade 1C recommendation) [2]. The purpose is to better characterize the nodule and asses its malignant potential. To our knowledge, there is no relevant literature describing effective ways to discriminate between benign and malignant nodules on radiographs [2].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. The mean attenuation value of indeterminate benign and malignant nodules on unenhanced CT is not significantly different and therefore not useful in their differentiation. However, multiple imaging features that increase the risk of malignancy are best characterized on CT including nodule size, morphology, location, multiplicity, or the presence of emphysema or fibrosis. Even though nodules <6 mm have a malignancy risk <1%, an optional follow- up CT can be recommended if some of these features are present (see Appendix 1).


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. CT Chest With IV Contrast There is no relevant literature to support the use of contrast-enhanced CT in the evaluation of incidentally detected indeterminate pulmonary nodules measuring <6 mm on chest CT. IV contrast is not required to identify or determine stability of pulmonary nodules [27].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest in the evaluation of incidentally detected indeterminate pulmonary nodules measuring <6 mm on chest CT.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of dynamic MRI chest in the evaluation of incidentally detected indeterminate pulmonary nodules measuring <6 mm on chest CT.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Female sex is included in the Brock University prediction model as a predictor of lung cancer [28]. Our literature search included a study by Chilet-Rosell et al [33] evaluating management differences between 545 men and 347 women from two institutions following the detection of incidental pulmonary nodules over 5 years. If the nodule was detected by CT, men were more likely to have immediate testing than women (P < .001), and women were followed-up more frequently than men (P < .001). In the multivariate analysis adjusted by age, smoking status, chronic obstructive pulmonary disease, and nodule characteristics, women were still more likely than men to be followed-up (P = .002). The median time between nodule detection and those diagnosed with lung cancer was 1.5 months for men and 4.2 months for women (no statistical difference). Authors raise the question that management variability could be related to a false belief that lung cancer is considered a disease of men. This was a small study, and further research exploring management differences are warranted to better understand the impact of sex in the management of lung nodules.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Vascularity differences between benign and malignant nodules have been described showing that malignant nodules are more vascular [30]. Nodule enhancement, which reflects vascularity, can be quantified with dynamic contrast- enhanced CT. This technique is highly sensitive in detecting malignant nodules but is nonspecific, mainly because of active inflammatory and infectious nodules also showing high vascularity [2,28]. Different enhancement cut-off values have been proposed to help with this problem. Lower cut-offs generally come with higher sensitivity but decreased specificity. Perfusion values are also influenced by technique, highlighting the need to be cautious when generalizing study results [34].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Incidentally Detected Indeterminate Pulmonary Nodule


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. selection bias. Radiation dose was also discussed, suggesting their technique might not be appropriate for women with low pretest probability of malignancy [29]. Several other series have reported low specificity values [2,32].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Although enhancement patterns of solid nodules have been widely studied, this is not the case for part-solid nodules. Cohen et al [35] retrospectively studied the differences in semiautomated attenuation measurements on unenhanced and enhanced CTs of 53 adenocarcinomas presenting as part-solid nodules. The study showed that most parameters were significantly increased on enhanced CT, including longest transverse diameter of the whole nodule, the solid component, nodule volume and mass, solid component volume and mass, and nodule attenuation. The only parameter that was not significantly elevated was the solid component attenuation, highlighting that caution must be taken when comparing part-solid nodules obtained on studies with and without IV contrast.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. The role of FDG-PET/CT in the differentiation of benign from malignant nodules has been extensively studied and relies on measuring glucose metabolism, which is typically elevated on malignant lesions. Reported sensitivities and specificities range from 88% to 96% and 77% to 88%, respectively [1,5,32]. Given PET limited spatial resolution, its use in the management of incidental pulmonary nodules is suggested for nodules >0.8 cm [2,9,40]. Nodule size (generally >0.8 cm), nodule attenuation, selected patient cohorts, how a malignant nodule is defined,


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Incidentally Detected Indeterminate Pulmonary Nodule and technical factors vary by study and should be considered when making conclusions about reported sensitivities and specificities.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. PET/CT and contrast-enhanced CT have been compared for the evaluation of solitary pulmonary nodules on small series, with results favoring PET/CT over dynamic CT. Christensen et al [36] showed sensitivities and specificities of 96% and 76% for PET/CT versus 100% and 29% for dynamic CT. Yi et al showed sensitivity, specificity, and accuracy of 96%, 88%, and 93% for PET/CT versus 81%, 93%, and 85% for dynamic CT, respectively [5,32].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. False-negative results on PET/CT go beyond small nodule size (<0.8 cm). Certain malignant tumors show low metabolic activity including carcinoid and adenocarcinoma regardless of size (those with predominant ground-glass component, small solid components, and mucinous type). PET/CT is not a reliable test to distinguish benign from malignant ground-glass nodules (or part-solid nodules with small solid components). Because of the indolent behavior of ground-glass nodules, PET/CT sensitivity is low and follow-up chest CT is preferred [9,26-28]. Defective technique can also result in false-negative studies [4,41,42].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. False-positive results on PET/CT also exist, mostly infectious and inflammatory lesions and less frequently sarcoidosis and rheumatoid nodules. Decreased FDG-PET/CT specificity to differentiate benign from malignant nodules has been recognized in regions with high prevalence of lung infections and reported as low as 25% in areas of endemic tuberculosis [40,43]. A meta-analysis of 70 studies showed FDG-PET/CT specificity adjusted for endemic infectious lung disease was 61% (95% CI, 49%-72%) compared to nonendemic regions 77% (95% CI, 73%-80%) [40,44]. Reyes et al [45] conducted a retrospective study comparing 351 biopsy-proven granulomatous and malignant nodules in a coccidioidal endemic region. Authors found that an elevated maximum standardized uptake value (SUVmax) was the only distinguishing feature between benign and malignant nodules. All nodules with SUVmax >5.9 were malignant, but there was overlap in nodules with SUVmax <5.9. Using an SUVmax <5.9, the sensitivity and specificity were 69% and 100%, respectively. This limitation should be recognized in endemic areas because it could alter the choice of next steps to more conservative options such as short-term follow-up CT.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. FDG-PET/MRI Whole Body There is no relevant literature to support the use of PET/MRI in the initial evaluation of incidentally detected pulmonary nodules. The use of FDG-PET/MRI in humans was first described in the early 2000s. PET/MRI integrates anatomic and functional MRI data with the metabolic information of PET. Interest around PET/MRI includes functional information and higher soft-tissue contrast resolution. An international survey of active whole- body PET/MRI sites showed oncology as its main application. Perceived challenges to its widespread use included study duration (2 times longer than a typical PET/CT), lack of standardized protocols, and challenges with interpretation (>80% sites had radiologist and nuclear medicine physicians jointly reporting as opposed to 40% for PET/CT) [46]. When imaging the lungs, PET/MRI faces the same challenges as lung MRI. Small nonavid nodules are usually missed, and finding precise anatomic correlates for areas of lung uptake can be difficult.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. 9 Incidentally Detected Indeterminate Pulmonary Nodule


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. 21.4% of the missed nodules were rated malignant. This resulted in one patient being upstaged from tumor stage I to IV [50].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Further advances on PET/MRI are needed before it is implemented in clinical practice, and current research points toward its use in oncology as opposed to incidental pulmonary nodule characterization.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. The most common complication of TNB is pneumothorax, and rates vary in series based on technique and study design. Two meta-analysis reported pooled rates of pneumothorax and hemoptysis of 19% to 25.3% and 4.1% to 12%, respectively [52,56]. Other studies report pneumothorax in 16% to 45% of cases and pneumothorax requiring a chest tube in 1.8% to 15% [52,53,56]. A meta-analysis of 46 studies from 2010-2015 described complication rates of CT-guided core-needle and FNA biopsy. They found that minor complications were more common in FNA, major complications were rare, and that smaller nodules, larger needle diameter, and increased transverse lung were risk factors for FNA complications. Complication rate for core biopsy was 38.8% versus 24.0% for FNA (P < .001). Major complications were 5.7% and 4.4% for core biopsy and FNA, respectively (no statistical significance). Pooled complication rates for CT-guided core-needle biopsy included pneumothorax 25.3%, pneumothorax requiring intervention 5.6%, pulmonary hemorrhage 18.0%, and hemoptysis 4.1%. For FNA, complication rates were lower: 18.8%, 4.3%, 6.4%, and 1.7%, respectively [56]. A retrospective single-institution study of 550 patients found no statistical differences between pneumothorax rates between 18-G and 20-G CT-guided pulmonary nodule biopsies (25.6% versus 28.7%, respectively). Chest tube insertion rate for 18-G and 20-G was 4.8% versus 5.6%,


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. 10 Incidentally Detected Indeterminate Pulmonary Nodule


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest in the evaluation of incidentally detected indeterminate pulmonary nodules. MRI has been increasingly studied as an alternative method in the evaluation of incidental pulmonary nodules over the last decades, with reported sensitivities ranging from 26% to 96% for various MRI sequences [54]. Major limitations for accurate nodule characterization include artifact from respiratory and cardiac motion and poor image contrast in lung MRI.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Motion artifact in pulmonary MRI results from longer sequence acquisition times compared to CT. Faster sequences and techniques have been studied to address this problem [57]. A small series by Heye et al [58] using a fast sequence reported a nodule detection rate of 45.5% compared to CT, along with a high number of false-positive nodules related to motion artifact. Nodule size is another well-known limiting factor for many MRI sequences.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Overall, MRI might have a future role as a complementary tool in the stratification of incidental pulmonary nodules, possibly multiparametric MRI, but further research and validation studies are required before MRI is implemented in clinical practice. Current pulmonary nodule guidelines do not include MRI in the management algorithms for incidental pulmonary nodules [2,9].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of dynamic MRI chest in the evaluation of incidentally detected indeterminate pulmonary nodules. MRI has been increasingly studied as an alternative method in the evaluation of incidental pulmonary nodules over the last decades, with reported sensitivities ranging from 26% to 96% for various MRI sequences [54]. Major limitations for accurate nodule characterization include artifact from respiratory and cardiac motion and poor image contrast in lung MRI, which are addressed on the MRI Chest Without IV Contrast section.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Similar to dynamic contrast-enhanced CT, dynamic MRI techniques have been proposed to differentiate benign from malignant pulmonary nodules. Reported sensitivities range from 52% to 100%, specificities from 17% to 100%, and accuracies from 58% to 96% [54,64]. Factors contributing to the wide ranges include variable study design, different sequences studied, and lower performance in cohorts living in areas with high prevalence of active infection. The authors have looked into improving the performance of dynamic contrast-enhanced MRI by adding semiquantitative analysis [65] or combining it with additional sequences, with a small series showing improved specificity and minimal improved accuracy in differentiating benign from malignant solitary nodules [54,66].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Incidentally Detected Indeterminate Pulmonary Nodule Overall, MRI might have a future role as a complementary tool in the stratification of incidental pulmonary nodules, possibly multiparametric MRI, but further research and validation studies are required before MRI is implemented in clinical practice. Current pulmonary nodule guidelines do not include MRI in the management algorithms for incidental pulmonary nodules [2,9].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Radiography Chest There is no relevant literature to support the use of chest radiographs in the evaluation or follow-up of incidentally detected indeterminate pulmonary nodules on chest CT. Radiograph sensitivity for detecting nodules is low, with a significant number of nodules missed [5]. Most nodules <1 cm are not visible in chest radiographs [9]. In addition, radiographs lack the resolution to adequately characterize nodules.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Variant 4: Adult greater than or equal to 35 years of age. Incidentally detected indeterminate pulmonary nodule on incomplete thoracic CT (eg, CT abdomen, neck, spine, etc). Next imaging study. Lungs are partially seen on CT from other body parts including neck, spine, heart, and abdomen. Pulmonary nodules are frequently encountered on these studies and are described as the most common incidental finding by some authors [67-69]. Reported nodule incidence ranges from 8% to 23% for coronary CT angiography [7,69,70], 16.4% to 28.2% for patients undergoing CT for transcatheter aortic valve implantation [67,68,71], and 2.5% to 39.1% for abdominal CTs [72-74].


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. The most updated Fleischner Society guidelines address the management of nodules found on incomplete thoracic CT. Please refer to Appendix 3 for details.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. CT Chest Without and With IV Contrast There is no relevant literature to support the use of dynamic contrast-enhanced CT in the evaluation of incidentally detected indeterminate pulmonary nodules encountered on incomplete thoracic CT.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Incidentally Detected Indeterminate Pulmonary Nodule CT Chest With IV Contrast There is no relevant literature to support the use of contrast-enhanced CT in the evaluation of incidentally detected indeterminate pulmonary nodules encountered on incomplete thoracic CT. Cancer staging, an incidental mass workup, and nodules with associated lymphadenopathy fall outside of the scope of this document.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. FDG-PET/CT Whole Body There is no relevant literature to support the use of FDG-PET/CT in the evaluation of incidentally detected indeterminate pulmonary nodules encountered on incomplete thoracic CT.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. Image-Guided Transthoracic Needle Biopsy There is no relevant literature to support the use of image-guided TNB in the evaluation of incidentally detected indeterminate pulmonary nodules encountered on incomplete thoracic CT.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. MRI Chest Without IV Contrast There is no relevant literature to support the use of MRI chest without IV contrast in the evaluation of incidentally detected indeterminate pulmonary nodules encountered on incomplete thoracic CT.


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. MRI Chest Without and With IV Contrast There is no relevant literature to support the use of dynamic MRI chest in the evaluation of incidentally detected indeterminate pulmonary nodules encountered on incomplete thoracic CT.


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


Incidentally Detected Indeterminate Pulmonary Nodule PCAs. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. Introduction/Background Acute onset of a cold, painful leg, also known as acute limb ischemia (ALI), describes the sudden loss of perfusion to the lower extremity and carries significant risk of morbidity and mortality. The pathophysiology primarily relates to acute arterial ischemia, in which there is often insufficient vascular collateralization to perfuse the lower extremity. A minority of cases may be related to a severe presentation of venous thrombotic disease. Known as phlegmasia cerulea dolens, this condition presents with lower extremity dusky discoloration, massive swelling, and pain. These clinical differences allow for differentiation from acute arterial ischemia.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. ALI requires rapid identification and treatment. The objectives of diagnostic imaging include confirmation of diagnosis, identifying the location and extent of vascular occlusion, and preprocedural/presurgical planning. The published literature regarding imaging of peripheral artery disease (PAD) focuses almost exclusively on patients with chronic PAD. This includes asymptomatic PAD, leg pain with exertion (ie, intermittent claudication), and critical limb ischemia (defined as chronic leg or foot pain at rest, skin ulceration, or gangrene). By comparison, the literature on imaging patients with ALI is very limited. Consequently, the following discussion relies heavily on studies of patients with chronic PAD. This document has separated imaging appropriateness based on the clinical scenario of suspected ALI for which signs and symptoms may include pain, pallor, paresthesia/paralysis, poikilothermia, and pulselessness, or more rarely with symptoms of phlegmasia cerulea dolens as described above, acknowledging that some patients may present with any combination of the above or other comorbidities that may require imaging. Additionally, compartment syndrome also induces acute ischemia via a separate mechanism of tissue pressurization within a fixed volume, often in the setting of trauma or other injury. This entity may manifest overlapping symptomatology with ALI and should be excluded clinically before consideration of imaging modalities.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. 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.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. Reprint requests to: publications@acr.org


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold, Painful Leg

Sudden Onset of Cold Painful Leg. Sudden Onset of Cold, Painful Leg


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. Linear gadolinium-based agents used in contrast-enhanced MRI have previously been associated with nephrogenic systemic fibrosis (NSF) in patients with underlying renal dysfunction. However, in patients with acute kidney injury or stage 4/5 chronic kidney disease with current generation macrocyclic and linear agents (group II, ie, gadobenate dimeglumine, gadobutrol, gadoterate meglumine, gadoteridol, gadoxetic acid disodium) the risk of NSF is suggested to be so low that the potential harm of delaying or withholding contrast is likely to outweigh the risk of NSF in most clinical situations [5]. Group III agents (ie, gadoxetic acid disodium) have thus far demonstrated no unconfounded cases of NSF, although evidence is still limited. Of note, there is increasing evidence that gadolinium deposition occurs within the brain parenchyma, namely, within the dentate nuclei and globus pallidus, although with unknown clinical significance; this remains a topic of interest within MRI contrast safety [6].


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. Contrast-enhanced ultrasound (US) using microbubble-based intravenous (IV) contrast is being applied to a growing number of scenarios to demonstrate findings typically seen on contrast-enhanced CT and MRI. Early evidence has suggested the potential use of contrast-enhanced 3-D US to create targeted volumetric mapping of patent lower extremity arteries [7]. Using CT angiography (CTA), novel techniques such as 3-D fluoroscopy-CT fusion software have demonstrated potential to augment intraprocedural arterial navigation [8]. Investigations into combined noncontrast CT and MR angiography (MRA) fusion have also been undertaken, combining the vessel wall detail of CT with the luminal detail of MRI in preprocedural vessel mapping [9]. However, evidence remains limited for these techniques in the diagnosis of ALI.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold, Painful Leg


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. Discussion of Procedures by Variant Variant 1: Sudden onset of cold, painful leg. Suspected vascular compromise. Initial imaging. Arteriography Lower Extremity Catheter arteriography (digital subtraction angiography [DSA]) performed with iodinated contrast remains the definitive method for anatomic evaluation of lower extremity peripheral arterial disease, providing dynamic, time- resolved evaluation of vascular anatomy and vascular flow [11]. However, noninvasive cross-sectional angiography techniques (ie, CTA and MRA) are increasingly performed to confirm disease with a high degree of accuracy before the decision to catheterize and perform angiographic intervention [12-18]. Catheter arteriography is typically performed in the intraprocedural setting for interventional planning and imaging confirmation of therapeutic objectives [19,20].


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. The main disadvantages of arteriography are related to the invasive nature of the procedure, which imparts risks of vascular injury, infection, bleeding, and other complications [11,21], and which may require additional interventions and prolonged hospital stay. Arteriography has been criticized for its imperfect evaluation of outflow vessels, specifically for limited visualization of pedal vasculature and patent distal vessels beyond significant obstructive lesions [22]. Preprocedural examinations including duplex US, MRA, or CTA may provide useful information given these considerations and to inform preprocedural/presurgical planning [8].


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. CTA Abdomen and Pelvis with Bilateral Lower Extremity Runoff With IV Contrast CTA is useful in the diagnosis of ALI and peripheral arterial disease [12-18]. CTA in multiple meta-analyses has demonstrated sensitivity and specificity for detecting hemodynamically significant arterial stenosis of up to 96% and 96%, respectively, relative to DSA [15,18,23,24]. This cross-sectional imaging technique has several advantages over catheter arteriography via the manipulation of acquired imaging data, which includes thin axial, multiplanar, 3-D volume rendering, and maximum intensity projection reconstructions [25]. Additionally, poststenotic or postocclusive vascular anatomy and collateralization may be better demonstrated using CTA than by catheter arteriography.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. Compared to MRA, CTA demonstrates superior spatial resolution and shorter scan time, contributing to lower likelihood of motion degradation. CTA generally also is less susceptible to severe image degradation due to metal artifact.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. A major disadvantage of CTA is its limited ability to depict the lumen in heavily calcified arteries. Artifact induced by calcium can lead to an overestimation of stenosis [26]. Dual-energy CTA can be employed to reduce beam- hardening artifact from calcium or vascular stents [27,28].


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. CTA of the abdomen and pelvis can be obtained in addition to the lower extremity when aortoiliac disease is a concern or if the aorta and iliac arteries have not already been imaged and to assess for vascular suitability before endovascular intervention. CTA is considered the diagnostic reference standard over catheter angiography for aortic imaging [29,30].


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. CTA Lower Extremity with IV Contrast CTA is useful in the diagnosis of ALI and peripheral arterial disease [12-18]. CTA in multiple meta-analyses has demonstrated sensitivity and specificity for detecting hemodynamically significant arterial stenosis of up to 96% and 96%, respectively, relative to DSA [15,18,23,24]. This cross-sectional imaging technique has several advantages over catheter arteriography via the manipulation of acquired imaging data, including thin axial, 3-D volume rendering, and maximum intensity projection reconstructions [25]. Additionally, poststenotic or postocclusive vascular anatomy and collateralization may be better demonstrated using CTA than by catheter arteriography.


Sudden Onset of Cold Painful Leg


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. CTA of the abdomen and pelvis can be obtained in addition to the lower extremity when aortoiliac disease is a concern or if the aorta and iliac arteries have not already been imaged. The lack of visualization of the abdominal


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. Sudden Onset of Cold, Painful Leg aorta and iliac vessels precludes evaluation for suitability before endovascular intervention or if pathology extends cranially beyond the lower extremities.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. MRA Abdomen and Pelvis with Bilateral Lower Extremity Runoff With IV Contrast The widespread adoption of 3T magnets has allowed for higher spatial resolution and signal-to-noise ratio acquisitions. In multiple meta-analyses and prospective studies, contrast-enhanced MRA for the detection of hemodynamically significant arterial stenosis has yielded a sensitivity and specificity up to 97% and 96%, respectively, when compared to DSA [31-34].


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. Compared to CTA, MRA does not suffer from artifact related to calcium within small vessels. In addition, time- resolved sequences allow for dynamic visualization and separation of arterial and venous flow, allowing for increased diagnostic accuracy. In a study comparing to DSA, contrast-enhanced, time-resolved MRA at 3T with calf compression to prevent venous contamination demonstrated superior visualization of below-the-knee arterial vasculature than DSA [35]. Contrast-enhanced MRA may be an optimal imaging modality for patients at high risk for calcification of the distal arterial vessels, particularly patients with suspected significant arterial calcific plaque burden [16,36].


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. The imaging-related disadvantages of MRA include low signal-to-noise ratio, limited spatial resolution, longer acquisition times, and a greater potential for artifact-related image degradation, namely, from motion and susceptibility from metal stents and orthopedic hardware; techniques have been developed to address some of these issues [37-40]. Safety risks inherent to MRI should also be considered, such as magnetic field bioeffects.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. MRA of the abdomen and pelvis can be obtained in addition to bilateral lower extremity runoff when aortoiliac disease is a concern or if the aorta and iliac arteries have not already been imaged and to assess for vascular suitability before endovascular intervention.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. MRA Abdomen and Pelvis with Bilateral Lower Extremity Runoff Without IV Contrast Noncontrast MRA techniques have been in use for decades in the form of 2-D and 3-D time-of-flight. However, noncontrast MRA is rarely used in the setting of PAD or ALI because of long acquisition times relative to contrast- enhanced MRA and CTA. However, hardware advances and faster, novel sequences such as quiescent interval slice- selective MRA and flow-sensitive dephasing have demonstrated comparable diagnostic accuracies to contrast- enhanced MRA in the evaluation of PAD in multiple prospective studies and trials [41-43].


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. The imaging-related disadvantages of MRA relative to CTA include lower signal-to-noise ratio, limited spatial resolution, longer acquisition times, and a greater potential for artifact-related image degradation, namely, from motion and susceptibility from metal stents and orthopedic hardware; techniques have been developed to address some of these issues [37-40].


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. MRA of the abdomen and pelvis can be obtained in addition to bilateral lower extremity runoff when aortoiliac disease is a concern or if the aorta and iliac arteries have not already been imaged and to assess for vascular suitability for endovascular intervention.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. MRA Lower Extremity Without and With IV Contrast The widespread adoption of 3T magnets has allowed for higher spatial resolution and signal-to-noise ratio acquisitions. In multiple meta-analyses and prospective studies, contrast-enhanced MRA for the detection of hemodynamically significant arterial stenosis has yielded a sensitivity and specificity up to 97% and 96%, respectively, when compared to DSA [31-34].


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. Sudden Onset of Cold, Painful Leg MRA of the abdomen and pelvis can be obtained in addition to bilateral lower extremity runoff when aortoiliac disease is a concern or if the aorta and iliac arteries have not already been imaged. The lack of visualization of the abdominal aorta and iliac vessels precludes evaluation for suitability before endovascular intervention or if pathology extends cranially beyond the lower extremities.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. MRA Lower Extremity Without IV Contrast The imaging-related disadvantages of MRA relative to CTA include lower signal-to-noise ratio, limited spatial resolution, longer acquisition times, and a greater potential for artifact-related image degradation, namely, from motion and susceptibility from metal stents and orthopedic hardware; numerous techniques have been developed to address some of these issues [37-40].


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. Compared to MRA abdomen and pelvis with bilateral lower extremity runoff without IV contrast, the lack of visualization of the abdominal aorta and iliac vessels precludes evaluation for suitability for possible endovascular intervention or if pathology extends cranially beyond the lower extremities.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. US Duplex Doppler Aorta Abdomen Duplex Doppler US is a noninvasive, portable imaging modality that can be quickly performed and repeated without potential risk. Duplex Doppler US of the aorta and abdomen may suggest evidence of a proximal cause of sudden onset, cold, painful leg, for example, due to an acute aortic dissection or aortic thrombus; however, there is no relevant literature to support its use as an initial imaging modality to diagnose ALI.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. US Duplex Doppler Lower Extremity Duplex Doppler US is a noninvasive, portable imaging modality that can be quickly performed and repeated without potential risk. Duplex Doppler US of the lower extremity is potentially useful as an initial imaging procedure to confirm the absence of distal arterial flow in cases of suspected ALI. However, it is limited in diagnostic accuracy, poor accessibility of vessels, and shadowing from vascular calcifications [14,44,45], and is not useful as a standalone examination. The lack of visualization of the abdominal aorta and common iliac vessels precludes evaluation of pathology extending cranially beyond the lower extremities.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. 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.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold Painful Leg. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Sudden Onset of Cold Painful Leg

Sudden Onset of Cold, Painful Leg

Sudden Onset of Cold Painful Leg. Sudden Onset of Cold, Painful Leg


Fibroids

Fibroids. Introduction/Background Uterine fibroids (leiomyomas or myomas) are the most common neoplasm of the uterus. They are composed of benign smooth muscle cells embedded in an extracellular matrix of collagen, fibronectin, and proteoglycan [1]. The prevalence of fibroids varies with race. Black women have an estimated incidence of fibroids by age 50 exceeding 80%, whereas White women have an incidence approaching 70% [2]. Although incompletely understood, fibroid etiology is multifactorial. A combination of genetic alterations and endocrine, autocrine, environmental, and other factors such as race, age, parity, and body mass index all play a role in fibroid development. Black women are more likely to develop clinically significant disease at an earlier age and are subject to racial disparities, including higher rates of surgical intervention when compared with medical therapy, as well as lower rates of minimally invasive approaches [3-6].


Fibroids

Fibroids. Fibroid-associated symptoms peak in the perimenopausal years and decline after menopause. Menorrhagia is the most frequent symptom and often results in iron deficiency anemia. Other common symptoms include dysmenorrhea, pelvic pain and pressure, urinary urgency and frequency, and constipation. Fibroids may also impair fertility and/or cause obstetric complications [7]. Despite the high prevalence and protean symptoms, there are few randomized trials to guide therapy. Patient preferences and symptom severity help inform treatment choice with options ranging from medical therapy to surgery. Hysterectomy is curative. One-half to one-third of the approximately 600,000 hysterectomies performed annually in the United States are for symptomatic fibroids [1,4]. Uterine sparing therapies include medical therapy (eg, GnRH agonists, levonorgestrel-releasing intrauterine devices, contraceptive steroid hormones, and tranexamic acid), myomectomy, endometrial ablation, uterine fibroid embolization (UFE), MR-guided focused ultrasound (MRgFUS), and laparoscopic radiofrequency ablation. Of these, myomectomy and UFE are the most common, and in a recent multicenter, randomized, open-label trial comparing myomectomy to UFE, both therapies resulted in equivalent symptomatic improvement at 2 years [8].


Fibroids

Fibroids. Special Imaging Considerations Saline infusion sonohysterography (SIS), a minimally invasive procedure distending the endometrial cavity with saline, enables better delineation between endometrial pathologies (polyps, hyperplasia, synechiae, etc) and submucosal fibroids. Studies have shown an overall good agreement (kappa 0.80) between 3-D SIS and diagnostic hysteroscopy to classify submucosal fibroids [9,10]. SIS has also been shown to accurately depict the percentage intracavitary component of submucosal fibroids, a finding that often has treatment implications [11,12].


Fibroids

Fibroids. Three-dimensional transvaginal ultrasound (3-D TVUS) is a reconstruction of the US volumetric data into high- resolution multiplanar imaging, including real-time surface rendered images [13]. In initial assessment, 3-D US has been used along with 2-D US for uterine pathologies, mostly submucosal fibroids, and endometrial polyps. A study of 139 cases comparing 3-D US against hysteroscopy in diagnosing uterine cavity abnormalities showed a sensitivity and specificity of 87% and 100% in diagnosing submucosal leiomyoma [14]. However, another study showed no significant advantage of 3-D US over 2-D US in estimating intracavitary protrusion of submucosal


Fibroids

Fibroids. Reprint requests to: publications@acr.org


Fibroids

Fibroids. Fibroids fibroid with a reference standard of hysteroscopy and a moderate interobserver agreement of 3-D US for submucosal fibroid [15].


Fibroids

Fibroids. US elastography/sonoelastography is a technique that measures tissue strain. Strain elastography used with routine TVUS has shown increased diagnostic accuracy in identifying myometrial pathologies (fibroids and adenomyosis) from normal myometrium [16,17]. On sonoelastography, foci of adenomyosis are seen as brighter irregular shaped lesions (because of the presence of endometrial glands and stroma implanted within the myometrium), whereas fibroids are seen as well-delineated dark areas (secondary to stiffer/compressed smooth muscle fibers) [18,19]. Compression sonoelastography is a method of applying gentle compression causing alteration in size and shape of the lesion based on the tissue stiffness, which can be qualitatively (as a color map) or quantitatively recorded. Studies have shown high interobserver and intermethod agreement for the measurement of uterine and fibroid volumes on compression elastography [19] and excellent agreement between elastography-based diagnosis of fibroids and adenomyosis with MRI-based diagnosis [18].


Fibroids

Fibroids. The role of artificial intelligence in imaging fibroids is currently under investigation. There are several studies evaluating machine learning with textural analysis to improve the diagnostic accuracy of differentiating fibroids from sarcomas [20].


Fibroids

Fibroids. OR Discussion of Procedures by Variant Variant 1: Clinically suspected fibroids. Initial imaging. CT Pelvis There is no relevant literature to support the use of pelvic CT without or with intravenous (IV) contrast as initial imaging modality for clinically suspected fibroids.


Fibroids

Fibroids. MRI Pelvis MRI excels at identifying and mapping fibroids [21-25]. When MRI is clinically useful, the use of a gadolinium- based IV contrast agent is preferred for identification of fibroid vascularity and other characteristics [26]. Please see the ACR Manual on Contrast Media for additional information [27].


Fibroids

Fibroids. Signal intensity and contrast enhancement allow diagnosis of fibroids to include size, number and location, and assessment of vascularity and to help characterize them as classic, degenerated (hyaline, carneous, hydropic, fatty, cystic, and myxoid), cellular, or atypical [28-30]. Conventional MRI, however, cannot accurately differentiate fibroids from sarcomas, a critical distinction for surgical planning and optimizing outcomes [31-33]. Diffusion- weighted imaging with apparent diffusion coefficient (ADC), especially when incorporated into an MRI algorithm, has shown promising results in distinguishing the two entities [20,34-40]. In a large, case-controlled retrospective study of women with atypical uterine masses, a diagnostic algorithm based on enlarged lymph nodes, peritoneal implants, high diffusion MRI signal, and low ADC values was developed and validated. The resulting algorithm achieved a 98% sensitivity and a 96% specificity in the training set and 83% to 88% sensitivity and 97% to 100% specificity in the validation sets [34]. Machine learning with texture analysis is under investigation and may have the potential to improve diagnostic accuracy [20].


Fibroids

Fibroids. MRI can differentiate fibroids from alternative or comorbid conditions such as adenomyosis and endometriosis that often cause similar symptoms [41,42].


Fibroids

Fibroids. US Pelvis Transabdominal A combination of transabdominal US (TAUS) and TVUS of the pelvis is the most useful modality in the initial evaluation of suspected uterine fibroid or abnormal uterine bleeding [43-45]. TAUS is often useful in significantly


Fibroids

Fibroids. Fibroids enlarged fibroid uterus or large subserosal/pedunculated fibroids that may render poor visualization on TVUS because of limited field-of-view from poor acoustic penetration. A potential limitation of TAUS is the poor acoustic window from decompressed urinary bladder, retroverted uterus, large body habitus, and bowel gas [46].


Fibroids

Fibroids. US Pelvis Transvaginal TVUS provides higher contrast and spatial resolution and should be combined with the TAUS whenever possible to evaluate suspected uterine fibroid [46,47]. TVUS has a reported sensitivity of 90% to 99% for detecting uterine fibroids and a sensitivity of 90% and specificity of 98% for the diagnosis of submucosal fibroids [43,48,49]. Three- dimensional TAUS and TVUS along with Doppler has shown high accuracy in differentiating uterine fibroids from adenomyosis with a sensitivity, specificity, and negative predictive value of 93%, 96%, and 88% for fibroids and 96%, 93%, and 98% for adenomyosis [50].


Fibroids

Fibroids. In a meta-analysis by Bittencourt et al [51], the pooled sensitivity and specificity of 2-D TVUS with SIS in diagnosing submucosal fibroids was 94% and 81%, respectively. The limitations of TVUS are a limited depth of penetration and a shallow focal length that can limit the evaluation of large or subserosal/pedunculated fibroids.


Fibroids

Fibroids. US Duplex Doppler Pelvis Although Doppler imaging is labeled under separate imaging procedure per ACR methodology, this document considers it to be a standard component of pelvic US. Color Doppler is routinely used in pelvic US examinations to evaluate internal vascularity of pelvic/uterine findings and to differentiate between vascular and nonvascular tissue [47].


Fibroids

Fibroids. US duplex Doppler evaluation may also help in differentiating submucosal/intracavitary fibroids from endometrial polyps. Visualization of a vascular pedicle on transvaginal color Doppler imaging has a specificity of 95% to 98% and a negative predictive value of 81% to 94% for the detection of endometrial polyps [57,58].


Fibroids

Fibroids. Variant 2: Known fibroids. Treatment planning. Initial imaging. CT Pelvis There is no relevant literature to support the use of pelvic CT without or with IV contrast as initial imaging in treatment planning for symptomatic fibroids. CT, however, can better delineate calcified fibroids relative to US and MRI that may have treatment implications.


Fibroids

Fibroids. MRI Pelvis MRI is superior to US (transabdominal followed by transvaginal) for identifying and mapping fibroids and may alter management in up to 28% of patients [22-25,59-61]. When MRI is clinically useful, the use of a gadolinium- based IV contrast agent is preferred [26]. Please see the ACR Manual on Contrast Media for additional information [27].


Fibroids

Fibroids. Fibroid location, volume, number, T1- and T2-weighted signal intensity, and enhancement provide important pretreatment information [25,62-65]. Intracavitary fibroids may be amenable to hysteroscopic resection, whereas submucosal, intramural, and broad-based subserosal fibroids are amenable to UFE. Cervical fibroids may not respond as well or have a durable response to embolization. Submucosal and intramural fibroids that contact the endometrium may be expelled following successful UFE in 2.2% to 7.7% of cases [1,25,66]. Pedunculated fibroids, depending on location and stalk caliber, may be treated hysteroscopically, laparoscopically, or with UFE [25]. Postcontrast imaging allows assessment of fibroid viability, uterine artery anatomy, and detection of ovarian arterial collateral supply to the uterus [67-71]. Nonviable/autoinfarcted fibroids, found in up to 20% of UFE candidates, do not respond to UFE and are therefore important to identify at time of treatment planning [71]. A meta-analysis on the utility of ADC values concluded that, because of heterogeneity, it is unclear whether ADC values are useful to predict UFE response [72].


Fibroids

Fibroids. Conventional MRI, however, cannot accurately differentiate fibroids from sarcomas, a critical distinction for surgical planning and optimizing outcomes [31-33]. Diffusion-weighted imaging with ADC, especially when


Fibroids

Fibroids. Fibroids incorporated into an MRI algorithm, has shown promising results in distinguishing the two entities [20,34-40]. In a large, case-controlled retrospective study of women with atypical uterine masses, a diagnostic algorithm based on enlarged lymph nodes, peritoneal implants, high diffusion MRI signal, and low ADC values was developed and validated. The resulting algorithm achieved a 98% sensitivity and a 96% specificity in the training set and 83% to 88% sensitivity and 97% to 100% specificity in the validation sets [34]. Machine learning with texture analysis is under investigation and may have the potential to improve diagnostic accuracy [20].


Fibroids

Fibroids. For patients undergoing MRgFUS, prediction models and multivariate analyses have found that nonperfused volume, a surrogate of symptom improvement, is a function of fibroid signal intensity, peak and time to peak enhancement, subcutaneous fat thickness, and distance from spine. A nonperfused volume >80% predicted clinical success in more than 80% of patients [73-76].


Fibroids

Fibroids. US Pelvis Transabdominal A combination of TAUS and TVUS of the pelvis is a frequently used imaging modality in pretreatment evaluation of known uterine fibroids [77,78]. TAUS is often useful in significantly enlarged fibroid uterus or large subserosal/pedunculated fibroids that may render poor visualization on TVUS because of limited field-of-view from poor acoustic penetration. A limitation of TAUS is a poor acoustic window from decompressed urinary bladder, retroverted uterus, large body habitus, and bowel gas [46].


Fibroids

Fibroids. US Pelvis Transvaginal TVUS provides higher contrast and spatial resolution and should be combined with the TAUS whenever possible to evaluate suspected uterine fibroid [46,47]. TVUS has a reported sensitivity of 90% to 99% for detecting uterine fibroids and a sensitivity of 90% and specificity of 98% for the diagnosis of submucosal fibroids [43,48,49]. The limitations of TVUS are a limited depth of penetration and a shallow focal length that can limit the evaluation of large or subserosal/pedunculated fibroids. The presence of numerous fibroids may also pose challenge in clearly delineating and precisely measuring the fibroids because of too poor an acoustic window.


Fibroids

Fibroids. US Duplex Doppler Pelvis Although Doppler imaging is labeled under separate imaging procedure per ACR methodology, this document considers it to be a standard component of pelvic US. Color and spectral Doppler are routinely used in pelvic US examinations to evaluate internal vascularity of pelvic/uterine findings and to differentiate between vascular and nonvascular tissue [47].


Fibroids

Fibroids. The growth of a uterine fibroid is proportional to its vascularity, and determining growth potential of the fibroid is helpful in clinical decision making [79,80]. Uterine artery Doppler flow measurements with peak systolic velocity >64 cm/s in uteri with fibroids have been shown as a predictor of UFE failure [81]. In a study by Nieuwenhuis et al [82], fibroid vascularization evaluated by 3-D TVUS with power Doppler correlated with fibroid volume and predicted fibroid growth rate per year. However, MRI pelvis has a higher sensitivity and accuracy than US in identifying number, location, size, volume, and vascularity of uterine fibroids for treatment planning [24,49,59].


Fibroids

Fibroids. Variant 3: Known fibroids. Surveillance or posttreatment imaging. CT Pelvis Although CT pelvis has no direct role in routine surveillance or posttreatment follow-up of uterine fibroids, CT, preferably with IV contrast, may be used following UFE in patients with pelvic pain, fever for acute postprocedural complications such as infection, hemorrhage, or pelvic venous thrombosis [83]. The overall serious post-UFE complication rate is 1.25%, with pulmonary embolism and infection (endometritis, pyometra, pyomyoma) occurring in up to 0.25% and 2% of patients, respectively [25,41,83].


Fibroids

Fibroids. MRI Pelvis When MRI is clinically indicated, the use of a gadolinium-based IV contrast agent is preferred [26]. Please see the ACR Manual on Contrast Media for additional information [27].


Fibroids

Fibroids. Routine posttreatment surveillance is controversial, and there is no consensus when to image asymptomatic women postintervention. Most studies evaluate patients immediately, 3 months, and/or 12 months after treatment and rely on T1-weighted, T2-weighted, and postcontrast sequences. Parameters commonly assessed include uterine volume, fibroid volume, percent infarcted/nonperfused volume, ovarian arterial collateral supply to the uterus, and fibroid location [25,41,67,70,83-87]. Following technically successful UFE, >90% fibroid infarction on postcontrast imaging correlates with better symptom control and fewer reinterventions [88]. Fibroid location after treatment is also important, especially in cases of suspected fibroid expulsion, which occurs in 2.2% to 7.7% of cases [1,25,66].


Fibroids

Fibroids. Fibroids Specifically, intracavitary devascularized fibroid location predisposes to fibroid expulsion. Several studies show an association between diffusion-weighted imaging and ADC values and fibroid devascularization after UFE and MRgFUS [89-94]. Quantitative perfusion parameters have also been used to predict immediate MRgFUS ablation response [95].


Fibroids

Fibroids. US Pelvis Transabdominal A combination of TAUS and TVUS of the pelvis is a frequently used imaging modality in surveillance and posttreatment follow-up of known uterine fibroids [77,78]. TAUS is often useful in significantly enlarged fibroid uterus or large subserosal/pedunculated fibroids that can have poor visualization on TVUS because of limited field- of-view from poor acoustic penetration. Another potential limitation of TAUS is a poor acoustic window from decompressed urinary bladder, retroverted uterus, large body habitus, and bowel gas [46].


Fibroids

Fibroids. US Duplex Doppler Pelvis Although labeled under separate imaging procedure per ACR methodology, this document considers Doppler imaging to be a standard component of pelvic US. Color Doppler has been routinely used in pelvic US examinations to evaluate internal vascularity of pelvic/uterine findings and differentiate between vascular and nonvascular tissue [47]. UFE results in a marked reduction in fibroid size and disappearance of intrafibroid vascularity without a reduction in uterine vascularization that can be assessed with Doppler US [100]. In a retrospective study of 227 patients treated with UFE for fibroids, Doppler evaluation showed a significant decrease in uterine artery peak systolic velocity (mean, 21.85 cm/s) relative to pre-embolization peak systolic velocity (mean, 40.33 cm/s) and correlated with a decrease in fibroid size and volume [81].


Fibroids

Fibroids. 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.


Fibroids

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


Chronic Liver Disease

Chronic Liver Disease. Introduction/Background Chronic liver disease encompasses a variety of causes of chronic liver injury, including nonalcoholic fatty liver disease, hepatitis C, hepatitis B, alcohol-related liver disease, primary sclerosing cholangitis, autoimmune hepatitis, and others. These diseases can progress to hepatic fibrosis and cirrhosis, with associated complications of portal hypertension, gastrointestinal hemorrhage, refractory ascites, hepatic encephalopathy, and primary liver cancer [1- 3]. Liver disease accounts for approximately 2 million deaths per year worldwide, 1 million due to complications of cirrhosis and 1 million due to viral hepatitis and hepatocellular carcinoma. Cirrhosis and liver cancer account for 3.5% of all deaths worldwide [4]. In the United States, the leading cause of cirrhosis is hepatitis C, with approximately 1.3% of the population having chronic hepatitis C infection [1-3], and mortality related to cirrhosis and liver cancer is underestimated and may be increasing [5,6].


Chronic Liver Disease

Chronic Liver Disease. The progression of hepatic fibrosis to compensated cirrhosis to decompensated cirrhosis can be slow and clinically silent. Although the standard for diagnosis of hepatic fibrosis and cirrhosis is liver biopsy, this technique is costly, plagued by sampling errors, can be morbid, and is not well accepted for longitudinal disease monitoring [7,8]. Thus, accurate noninvasive methods are desperately needed for establishing and grading severity of liver fibrosis as well as monitoring disease progression or response to therapy. Although a variety of serum markers exist for this purpose, they are inaccurate for intermediate stages of fibrosis, and imaging by conventional ultrasound (US), CT, and MRI is frequently performed to assess for cirrhosis and its complications in this patient population [9]. More advanced techniques such as MR elastography and US have been shown to be more accurate than conventional morphological imaging methods and are gaining acceptance for these applications.


Chronic Liver Disease

Chronic Liver Disease. Hepatocellular carcinoma (HCC) is the most common primary liver cancer arising in patients with cirrhosis, and the American Association for the Study of Liver Disease (along with other major international guidelines) recommends surveillance for HCC in patients with cirrhosis who would benefit from early detection of HCC [10,11].


Chronic Liver Disease

Chronic Liver Disease. Imaging plays a central role in detection, staging, and treatment guidance for HCC. Surveillance has traditionally been performed with conventional US, followed by contrast-enhanced CT or MRI used for definitive diagnosis and staging of HCC [12,13]. However, there may be an emerging role for MRI-based surveillance in patients whose livers are poorly assessed by US. Contrast-enhanced US (CEUS) is becoming established as an accurate technique for assessment of liver masses, including HCC [14].


Chronic Liver Disease

Chronic Liver Disease. Discussion of Procedures by Variant Variant 1: Chronic liver disease. Diagnosis and staging of liver fibrosis. Initial imaging. Patients with chronic liver disease can present with findings of frank cirrhosis and portal hypertension, including jaundice and ascites. However, in many patients, the severity of liver disease is not apparent based on clinical or laboratory findings. In general, imaging can be helpful to confirm the presence of cirrhosis based on morphological


Chronic Liver Disease

Chronic Liver Disease. aDuke University Medical Center, Durham, North Carolina. bPanel Vice Chair, Northwestern University, Chicago, Illinois. cPanel Chair, Johns Hopkins University School of Medicine, Baltimore, Maryland. dUniversity of Arizona, Banner University Medical Center, Tucson, Arizona. eBaylor University Medical Center, Dallas, Texas; American Association for the Study of Liver Diseases. fMontefiore Medical Center, Bronx, New York. gUMass Medical School, Worcester, Massachusetts. hUniversity of Florida College of Medicine, Gainesville, Florida. iNew York University Medical Center, New York, New York. jStanford University Medical Center, Stanford, California. kUniversity of Alabama Medical Center, Birmingham, Alabama. lUniversity of Alabama Medical Center, Birmingham, Alabama. mJohns Hopkins Bayview Medical Center, Baltimore, Maryland. nUniversity of Illinois College of Medicine, Chicago, Illinois; American College of Physicians. oJohns Hopkins Hospital, Baltimore, Maryland. pSpecialty Chair, Virginia Commonwealth University Medical Center, Richmond, Virginia.


Chronic Liver Disease

Chronic Liver Disease. 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.


Chronic Liver Disease

Chronic Liver Disease. Reprint requests to: publications@acr.org


Chronic Liver Disease

Chronic Liver Disease

Chronic Liver Disease. Chronic Liver Disease


Chronic Liver Disease

Chronic Liver Disease. features. For patients without cirrhosis, determining the presence and severity of earlier stages of liver fibrosis may help guide management.


Chronic Liver Disease

Chronic Liver Disease. CT Abdomen Noncontrast CT has limited utility in the assessment of hepatic fibrosis because it relies on the demonstration of gross structural changes, which are typically not present until very advanced stages of the disease. Contrast- enhanced CT can be more useful because it can demonstrate parenchymal heterogeneity and enhancement of lattice- like macroscopic bands of fibrosis throughout the hepatic parenchyma [21,22]. CT perfusion has been described for the assessment of hepatic fibrosis and cirrhosis, predominantly relying on increased proportion of arterial blood supply to the liver as fibrosis progresses [23]. However, this methodology is highly technique dependent and requires substantial postprocessing and therefore is not considered a clinical standard method for establishing the diagnosis of cirrhosis. There is no relevant literature that demonstrates incremental value of combining noncontrast with contrast-enhanced CT for this application.


Chronic Liver Disease

Chronic Liver Disease. FDG-PET/CT Skull Base to Mid-Thigh Fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET is not a useful test for detecting liver fibrosis. Data are limited regarding its utility, and no advantage over alternative imaging or serum tests has been demonstrated.


Chronic Liver Disease

Chronic Liver Disease. MR Elastography Abdomen MR elastography is currently the most accurate imaging modality for the diagnosis and staging of hepatic fibrosis [24,25]. MR elastography compares favorably with US shear wave elastography (SWE), in part, because of improved performance in patients with obesity [26]. MR elastography does have limitations in patients with hepatic iron deposition and patients imaged at 3T due to susceptibility artifacts, which can result in undersampling of the liver or nondiagnostic evaluations. Stiffness measurement may also be confounded by parenchymal edema, inflammation, cholestasis, cardiogenic hepatic congestion, recent meal, and other factors [27].


Chronic Liver Disease

Chronic Liver Disease. MRI Abdomen Conventional MRI can be used to assess the same structural changes as those visualized on CT, with the added advantage of greater visibility of bands of fibrosis on both noncontrast and contrast-enhanced sequences [28]. However, its utility for detecting early liver fibrosis remains limited because these changes do not occur until fibrosis has progressed to a very advanced stage.


Chronic Liver Disease

Chronic Liver Disease. A number of advanced MRI techniques have been assessed for detecting liver fibrosis. Diffusion-weighted imaging has been used to assess the restriction of free water proton movement in the hepatic parenchyma as a marker of collagen deposition, the microscopic manifestation of liver fibrosis. A meta-analysis of studies on diffusion- weighted imaging for this application showed that diffusion-weighted imaging was most useful for detecting advanced fibrosis but had lower performance for detecting early fibrosis (sensitivity 77%, specificity 78%) [29]. Additionally, questions about the optimal acquisition technique and image processing methodologies (apparent diffusion coefficient, intravoxel incoherent motion, etc) remain unresolved.


Chronic Liver Disease

Chronic Liver Disease. MR perfusion techniques have been described and found to be relatively accurate for the diagnosis and staging of liver fibrosis [30]. However, like CT perfusion, these are dependent on details of the acquisition and processing techniques and can be quite laborious, so they are not broadly used in clinical practice.


Chronic Liver Disease

Chronic Liver Disease. US Abdomen Conventional US can be used in the assessment of liver fibrosis for detecting ultrastructural changes such as surface nodularity, coarsened echotexture, and lobar atrophy/hypertrophy, similar to conventional CT and MRI [24,33,34].


Chronic Liver Disease

Chronic Liver Disease


Chronic Liver Disease

Chronic Liver Disease. US has an advantage in that high spatial resolution imaging of the liver surface can be performed with high frequency transducers, which can demonstrate subtle surface nodularity.


Chronic Liver Disease

Chronic Liver Disease. US Abdomen with IV Contrast US abdomen with IV contrast or CEUS has been assessed for evaluation of liver fibrosis. Similar to CT and MRI perfusion techniques, CEUS uses contrast media transit characteristics to make deductions about liver hemodynamics that relate to the presence and severity of liver fibrosis [35,36]. Although early data on the utility of CEUS for assessing liver fibrosis and portal hypertension are promising, this is an area of ongoing research at this time.


Chronic Liver Disease

Chronic Liver Disease. US Duplex Doppler Abdomen Doppler US can demonstrate hemodynamic alterations indicative of portal hypertension, though these are typically only seen in the setting of long-standing fibrosis or cirrhosis [40,41]. Though only moderately sensitive for advanced fibrosis/cirrhosis, it can be used for initial assessment of patients with suspected long-standing chronic liver disease in combination with conventional grayscale US.


Chronic Liver Disease

Chronic Liver Disease. Cirrhosis due to vascular conditions is a special case in which surveillance for HCC is more complex. Underlying vascular conditions include Budd-Chiari syndrome, hepatic congestion particularly in the setting of congenital heart disease, hereditary hemorrhagic telangiectasia, and others. The utility of imaging for diagnosis of cirrhosis and accuracy for characterizing HCC is less well established, particularly because these patients often develop benign regenerative liver nodules. Optimal utilization of imaging in these patients must be established for each condition based on available data and is not addressed in this document.


Chronic Liver Disease

Chronic Liver Disease. in whom the utility of US may be limited. Little value has been demonstrated for the addition of noncontrast to contrast-enhanced CT in this setting.


Chronic Liver Disease

Chronic Liver Disease. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT is not a useful test for screening or surveillance for HCC. FDG uptake by HCC is highly variable, and combined with high background liver FDG uptake, the PET portion of these examinations adds little to multiphase contrast-enhanced CT [49].


Chronic Liver Disease

Chronic Liver Disease. MR Elastography Abdomen MR elastography has been investigated for the assessment of focal liver lesions with modest success [50]. However, limited spatial resolution and coverage of MR elastography renders it of limited utility for screening and surveillance.


Chronic Liver Disease

Chronic Liver Disease. MRI Abdomen Dynamic contrast-enhanced MRI has been shown to be the most accurate modality in detecting and characterizing HCC, with sensitivity reported between 47% to 95% even for lesions <2 cm [46-48,51-54]. MRI most commonly serves as a second-line confirmatory diagnostic test for assessing nodules detected with US, though it may have a role for screening and surveillance of patients in whom US is expected to be of lower utility [55]. Because the detection and characterization of HCC relies mainly on the perfusion features of liver lesions, MRI without IV contrast is not typically performed for this purpose. MRI with hepatobiliary contrast agents has been shown to be similarly sensitive for detection of HCC compared with extracellular agents, and potentially more sensitive (up to 96% in a recent meta-analysis but only 88% in a more recent study) for detection of small lesions [56]. However, challenges with transient respiratory motion artifacts, judging washout, and other technical limitations must be considered [57,58].


Chronic Liver Disease

Chronic Liver Disease. US Abdomen with IV Contrast CEUS has been shown to be highly sensitive for the diagnosis of HCC at centers of excellence [14,67,68]. However, CEUS requires focused observation of a single region of interest, and although the ability to reinject after a period of washout allows for more than one region to be evaluated during a single examination, this may not be well-suited for whole-liver assessment as is needed for screening and surveillance [69].


Chronic Liver Disease

Chronic Liver Disease

Chronic Liver Disease. Chronic Liver Disease


Chronic Liver Disease

Chronic Liver Disease. US Shear Wave Elastography Abdomen The use of SWE has been described for assessment of focal liver lesions in a limited number of small studies [70,71]. However, SWE assessments are typically performed slice by slice; thus, the technique is poorly suited to whole- liver surveillance. To date, most reported investigations on the application of SWE in the liver have focused on liver fibrosis assessment and, to a lesser extent, on differentiating benign from malignant focal lesions.


Chronic Liver Disease

Chronic Liver Disease. US Duplex Doppler Abdomen Doppler US is typically performed in conjunction with conventional grayscale US assessment. The duplex Doppler component may add value to the grayscale examination, allowing tumor in vein to be more readily identified.


Chronic Liver Disease

Chronic Liver Disease. Variant 3: Chronic liver disease. Previous diagnosis of HCC. Post-treatment monitoring for HCC. Treatment options for patients with HCC may include liver transplantation, surgical resection, external beam radiation therapy, chemotherapy, and locoregional treatments, including percutaneous ablative and embolic modalities. After liver transplantation and surgical resection with negative margins, the goal of post-treatment monitoring is surveillance for new foci of HCC. After treatments in which the HCC is not actually removed, both monitoring of the treatment site as well as surveillance for distant foci of HCC must be accomplished. Thus, whole- liver surveillance remains an important goal after treatment.


Chronic Liver Disease

Chronic Liver Disease. CT Abdomen CT of the abdomen without and with IV contrast is an accurate method for detecting recurrence of HCC following locoregional therapy, resection, or transplantation. After locoregional therapy, including a precontrast phase, CT is strongly recommended because treatment can render a lesion or perilesional treatment zone high in attenuation (particularly when ethiodized oil is used in embolization), which can confound the interpretation of the hepatic arterial phase [72,73]. Noncontrast CT has a limited role because the detection of recurrent HCC relies primarily on detecting abnormal tumor perfusion. Dual-energy CT can be utilized to derive virtual unenhanced images and/or iodine maps for the same purpose as a dedicated precontrast acquisition. [74]. The National Comprehensive Cancer Network guidelines recommend CT or MRI every 3 to 6 months for 2 years and then every 6 to 12 months after HCC resection, whereas the European Association for the Study of the Liver recommends multiphase CT or MRI to assess response 1 month after resection or locoregional or systemic therapies, followed by one imaging technique every 3 months to complete at least 2 years, and then regular US every 6 months thereafter [75].


Chronic Liver Disease

Chronic Liver Disease. FDG-PET/CT Skull Base to Mid-Thigh The utility of FDG-PET/CT in HCC patients has primarily been investigated in the pretreatment setting; little data are available regarding post-treatment monitoring [76]. Because of the need for multiple repeated examinations and efficacy of multiphase contrast-enhanced CT and MRI, FDG-PET/CT is infrequently used for monitoring for HCC recurrence.


Chronic Liver Disease


Chronic Liver Disease

Chronic Liver Disease. MRI Abdomen MRI of the abdomen without and with IV contrast is highly sensitive for detecting HCC recurrence. Multiple contrast mechanisms (perfusion, diffusion, hepatobiliary agent uptake, intrinsic T1- and T2-weighted signal intensity) can be used for assessment; however, arterial phase hyperperfusion remains the mainstay for detection of HCC recurrence. Both the National Comprehensive Cancer Network and the European Association for the Study of the Liver recommend CT or MRI at regular intervals for at least 2 years for follow-up of patients with treated HCC [77]. The role of hepatobiliary MRI in this setting remains controversial. It has been shown to increase sensitivity for detection of small lesions, but may overdiagnose premalignant lesions [78]. In addition, imaging artifacts are more common with gadoxetate disodium, the primary agent used for hepatobiliary imaging, and use of hepatobiliary agents may reduce the yield of the early perfusion assessment of lesions [57].


Chronic Liver Disease

Chronic Liver Disease. Because the detection and characterization of HCC relies mainly on the perfusional features of liver lesions, MRI without IV contrast is not typically performed for this purpose. However, noncontrast MRI may be a reasonable modality for surveillance, because it offers the best differentiation between types of soft tissues of the available noncontrast modalities.


Chronic Liver Disease

Chronic Liver Disease


Chronic Liver Disease

Chronic Liver Disease. US Abdomen Because of the importance of vascular perfusion and the absence of morphological changes in early HCC recurrence, US is not typically utilized as the only surveillance modality for assessing for recurrent HCC following treatment. The European Association for the Study of the Liver recommends multiphase CT or MRI to assess response 1 month after resection or locoregional or systemic therapies, followed by one imaging technique every 3 months to complete at least 2 years, and then regular US every 6 months thereafter [77].


Chronic Liver Disease

Chronic Liver Disease. US Abdomen with IV Contrast CEUS has been shown to be highly sensitive for the diagnosis of HCC at centers of excellence [14,67,68]. CEUS requires focused observation of a single region of interest during contrast injection, and although the ability to reinject after a period of washout allows for more than one region to be evaluated in a single examination, this method may not be well-suited for whole-liver assessment as is needed for screening and surveillance [69]. Early clinical data suggest that CEUS could have utility in monitoring both for local recurrence of HCC after locoregional therapy and for secondary surveillance, particularly given that most recurrence occurs in the same segment as the originally treated nodule [79,80]. In addition, CEUS may be an effective alternative when MRI or CT results are inconclusive [81].


Chronic Liver Disease

Chronic Liver Disease. US Shear Wave Elastography Abdomen The use of SWE has been described for assessment of focal liver lesions in a limited number of small studies [70,71,82]. However, SWE assessments are typically performed slice by slice; thus, the technique is poorly suited to whole-liver surveillance. There is also a paucity of data regarding assessment of lesions that have undergone prior locoregional therapy. To date, most reported investigations on the application of SWE in the liver have focused on liver fibrosis assessment and, to a lesser extent on differentiating benign from malignant focal lesions.


Chronic Liver Disease

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


Chronic Liver Disease

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


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Introduction/Background Ultrasound (US) is the primary imaging modality in the evaluation of patients presenting with vaginal bleeding in the first trimester of pregnancy. Magnetic resonance imaging (MRI) and computed tomography (CT) play a minor role in problem-solving the causes of bleeding but may be useful when US is severely limited, for an unusual ectopic pregnancy, or when uncommon diagnoses are suspected. US correlated with serum human chorionic gonadotrophin (hCG) levels and clinical presentation can usually differentiate causes of first-trimester bleeding. These include normal intrauterine pregnancy (IUP) with or without a subchorionic hematoma, nonviable IUP, gestational trophoblastic disease (GTD), and ectopic pregnancy, which can all present with vaginal bleeding. Bleeding in the first trimester occurs in 7% to 27% of pregnancies, with an overall risk of miscarriage of approximately 12% [1]. US can usually differentiate an intrauterine from an ectopic pregnancy and a viable from a nonviable IUP. An overview of relevant US findings follows. Although it is important to diagnose ectopic pregnancies and nonviable IUPs, one should also guard against injury to normal pregnancies. Potential harm to a normal pregnancy can occur because of overinterpretation of a single US, misunderstanding the usefulness of the discriminatory level or serial values of hCG, and inappropriate treatment with methotrexate or dilation and curettage [2].


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Variant 1: First trimester vaginal bleeding. Positive urine or serum pregnancy test. US Transvaginal Intrauterine fluid collection The first visible US evidence of an IUP is a small spherical fluid collection with a hyperechoic rim, representing the gestational sac, located within the endometrium. Using high-frequency transvaginal transducers (generally about 7 MHz or higher), gestational sacs as small as 2 to 3 mm in mean sac diameter (MSD) may be visualized, corresponding to 4.5 to 5 weeks of gestation [3]. Prior to the identification of a yolk sac or embryo in the gestational sac, the intradecidual sign may be helpful to confirm an IUP. The intradecidual sign consists of an intrauterine fluid collection with a hyperechoic rim located in the endometrium separate from the central echogenic line that represents the collapsed endometrial cavity [4,5]. This sign, which can be visualized as early as 4.5 weeks, increases the probability of an IUP but is not reliable for diagnosing an IUP [6,7]. It can be difficult to apply the intradecidual sign in some patients, as the central echogenic line is not always evident. The double decidual sac sign, typically defined as two echogenic rings around the intrauterine fluid collection, is another finding that seems to increase the likelihood of an IUP but is not a reliable sign and is of limited usefulness for confirming an IUP [7-9]. The intradecidual sign and the double decidual sac sign both have poor interobserver agreement and neither is required for the diagnosis of an IUP [7].


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Before a yolk sac or embryo is seen, there has been concern that fluid in the endometrial cavity, sometimes termed a pseudogestational sac, might be confused for a gestational sac. However, pseudogestational sacs can usually be recognized based on their shape (acute angle at the edge), contents (internal echoes), or location (in the endometrial cavity) [10]. If a nonspecific fluid collection in the uterus does not have the features of a pseudogestational sac, it should be interpreted as likely representing a gestational sac, and one should generally


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Reprint requests to: publications@acr.org


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. First Trimester Vaginal Bleeding


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. not undertake a treatment that could cause unintended harm to an IUP [7,10]. Rarely, a decidual cyst [11] could be mistaken for a gestational sac but usually does not have an echogenic rim and is usually not adjacent to the central echogenic line of the collapsed endometrial cavity.


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. The discriminatory level of hCG refers to the level at which a gestational sac should always be seen on transvaginal US in a normal singleton IUP and has historically been suggested as 1,000 to 2,000 mIU/mL [12,13]. However, even a level of 2,000 mIU/mL has been found to be too low to exclude a normal IUP [14-16]. If there is no transvaginal US evidence of a gestational sac when a single serum hCG is 3,000 mIU/mL or higher, it is unlikely there will be a viable IUP [17]. For a hemodynamically stable patient with no sonographic evidence of an IUP or ectopic pregnancy, management decisions should generally not be made based on a single hCG level [16,17] . Follow-up hCG assay and US are usually appropriate in such a scenario.


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Definite intrauterine gestation The yolk sac, a thin-walled, spherical structure with an anechoic center, is the first sonographic feature that confirms an IUP [8]. It is usually visualized by transvaginal US in a gestational sac >8 mm in MSD [18]; however, in some normal pregnancies the gestational sac will be larger before a yolk sac is seen [19]. The embryo will initially appear as a thickened, linear echogenic structure at the edge of the yolk sac. With transvaginal US, the embryo is usually seen by about 6 weeks gestational age and by the time the gestational sac grows to a MSD of 16 mm; however, in some normal pregnancies the gestational sac will be larger before an embryo is seen [20].


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Once an IUP is definitely established by US, various US findings may be seen that are associated with a nonviable IUP. These include bradycardia [23,24], small gestational sac compared to embryo [25], enlarged amniotic cavity [26], empty amniotic cavity [27], absence of cardiac activity with visualization of the amnion [28], and abnormal size or shape of the yolk sac [29]. However, these findings are not definitive for a nonviable IUP, and in these situations, follow-up US in correlation with serial quantitative serum beta hCG measurements is often useful. Subchorionic hematomas are not an infrequent finding during the first trimester. They are usually small and not thought to substantially increase the risk of a nonviable pregnancy. Large (two-thirds or more of the gestational sac circumference) subchorionic hematomas may be associated with an increased risk of nonviable pregnancy [30].


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Ectopic pregnancy Whenever an IUP is not identified in a patient with a positive pregnancy test, extrauterine locations for the pregnancy should be carefully evaluated [31,32]. This involves identification of the ovaries and corpus luteum along with a careful search for any extraovarian mass that is not a paraovarian cyst or pedunculated fibroid because the vast majority of ectopic pregnancies are in the fallopian tube. Ectopic pregnancies are located ipsilateral to the corpus luteum in 70% to 80% of cases [33,34] and it is important to distinguish between the


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Although visualization of an extrauterine gestational sac with a live embryo is 100% specific for an ectopic pregnancy, this situation is uncommon [39]. More common, though slightly less specific, is an extrauterine mass with a fluid center and hyperechoic periphery, which has been termed a tubal ring [40,41]. Additionally, the ectopic pregnancy may appear as a nonspecific heterogeneous mass with no identifiable gestational sac within it. This latter appearance has been reported as the most common sonographic finding of a tubal pregnancy [39]. Even with such a nonspecific-appearing mass, tubal pregnancy is likely when the mass is outside the ovary (with no other obvious cause, such as a pedunculated fibroid or paraovarian cyst) in a patient with a positive serum hCG and no sonographic evidence of an IUP [41]. Given the potential for inappropriate management with methotrexate or surgical intervention, the diagnosis of ectopic pregnancy should generally be based on positive findings and not solely on the absence of an IUP.


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Assessment of any free intraperitoneal fluid is important in the evaluation for an ectopic pregnancy. In this setting, echoes within the free fluid are often due to blood. Trace anechoic free fluid in the pelvis is generally normal. The presence of more than a normal small amount of free fluid or echoes within the fluid, even without identification of an extraovarian mass, is concerning for an ectopic pregnancy [42-44]. However, this finding is not specific and can also occur for other reasons, such as rupture of a hemorrhagic ovarian cyst with an early, nonvisualized IUP.


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. A minority of ectopic pregnancies occur in locations other than the fallopian tube. The most common nontubal locations are interstitial, cervical, and within a Cesarean section scar. Three-dimensional US may be useful if an interstitial pregnancy is suspected but the diagnosis is uncertain based on 2-D US [45]. Rudimentary horn and abdominal pregnancies are less common, and ovarian ectopic pregnancy is rare. Coexisting intrauterine and extrauterine pregnancy (sometimes referred to as a heterotopic pregnancy) is rare, though is more likely to occur in women undergoing assisted reproduction techniques [46]. In general, for a woman with a spontaneously occurring pregnancy, identification of an IUP excludes a coexisting ectopic pregnancy with near complete certainty. However, the adnexa should still be routinely evaluated.


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Other causes of PUL include an early IUP (<4.5-5 weeks) or a nonvisualized ectopic pregnancy. A small minority of patients with PUL (probably about 7%-20% but likely more toward the lower end of that range), will later be diagnosed with an ectopic pregnancy [48]. Patients with a PUL can pose a diagnostic challenge. If the patient is hemodynamically stable, follow-up hCG and/or US should generally be performed before surgical or medical therapy is undertaken, regardless of the initial hCG level [15,16].


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Gestational trophoblastic disease When US does not show an intrauterine gestational sac, but rather a hyperechoic area in the endometrium with multiple cystic spaces [51], one should consider a complete molar pregnancy, the most common form of GTD. In the earlier part of the first trimester, this classic appearance may be absent and the sonographic findings more variable [52,53]. Complete molar pregnancy can sometimes appear similar to RPOC. Partial molar pregnancy can


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. be more difficult to diagnose sonographically than complete molar pregnancy [54,55] but should be considered if an embryo is present with cystic change in the early placenta. The US findings of partial molar pregnancy overlap those of a nonviable IUP with hydropic degeneration of the early placenta. The hCG is often, but not always, inappropriately elevated with GTD. Definitive diagnosis is based on histopathological evaluation of uterine contents.


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. US Transabdominal Most research studies have used transvaginal US, and there is little evidence in regards to diagnosis of nonviable IUP with transabdominal US alone. Transabdominal US may be adequate in some patients if the diagnosis is clear, such as when a viable IUP and normal adnexa are demonstrated in a patient with no risk factors for heterotopic pregnancy. Transabdominal US is more likely to be adequate later in the first trimester as opposed to the early first trimester.


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Ectopic pregnancy If an abnormal amount of free intraperitoneal fluid is identified in the pelvis, transabdominal US should be used to evaluate the flanks and dependent locations in the right upper (Morison pouch) and left upper quadrants. It is difficult to reliably predict tubal rupture by US [39]. Larger amounts of free intraperitoneal fluid correlate with ruptured ectopic pregnancy, but in about one-third of cases with a large amount of free intraperitoneal fluid, the fallopian tubes are intact [56]. Clotted blood in the pelvis can sometimes be mistaken for mesentery or blend in with adjacent organs such as the uterus and be difficult to recognize.


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. US Duplex Doppler When a normal or potentially normal IUP is present, pulsed Doppler US (whether spectral, color, or power Doppler) of the pregnancy should generally be avoided in the first trimester due to concerns about potential bioeffects in the developing embryo [57-59]. Documentation of embryonic cardiac activity is best done with M- mode US as the heart rate can be measured. Video clips can also be used to document embryonic cardiac activity.


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Once a normal IUP has been excluded, Doppler US may be useful when other diagnoses such as RPOC are suspected. Doppler US is not generally needed to make a diagnosis of GTD, but may be helpful as an ancillary tool in the management of some patients with GTD [60,61]. Doppler US is rarely useful for diagnosing tubal pregnancies as both the corpus luteum and a tubal pregnancy often have flow detected peripherally. Although Doppler US could conceivably be useful in some nontubal ectopic pregnancies such as cervical, interstitial, or Cesarean section scar pregnancies, its diagnostic utility for these diagnoses has not been well established in the literature.


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. MRI While an early pregnancy may be recognized on MRI, it generally is due to unintentional imaging of the pregnancy [67]. MRI is rarely needed for evaluating an IUP or tubal pregnancy. However, one may occasionally recognize tubal pregnancies on MRI [68], and MRI may be helpful as a problem-solving tool for nontubal ectopic pregnancies or GTD [69-71]. MRI may also help in cases of unusual implantation sites or in women with uterine anomalies. In pregnancy, gadolinium should be used with caution and only when critical and the potential benefits are felt to be justified [72]. Gadolinium is not generally recommended in a normal first-trimester pregnancy. MRI without gadolinium is thought to be safe in the first trimester of pregnancy [73].


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. First Trimester Vaginal Bleeding


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. RPOC may be identified by MRI, but MRI has little role in making the diagnosis of RPOC. RPOC and GTD may both manifest as an enhancing endometrial mass but are usually distinguishable on clinical grounds [74]. Contrast-enhanced pelvic MRI may be helpful to evaluate the extent of myometrial invasion and local extrauterine spread of GTD [75]. Uterine AVM can also be diagnosed with MRI [76].


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. CT An early IUP may be recognized on CT, but it is usually due to unintentional imaging of the pregnancy [67]. Because of its ionizing radiation, CT is generally not performed to evaluate vaginal bleeding in the first trimester of pregnancy. CT may identify an ectopic pregnancy [68], but reported cases of ectopic pregnancy diagnosed on CT were often performed for other reasons or in patients not known to be pregnant [77,78]. When a patient is clinically unstable, emergent care should generally not be delayed by additional imaging with CT or MRI. RPOC may be identified by CT, particularly when an enhancing mass is seen, but CT has little role in making the diagnosis of RPOC and the findings overlap those of GTD [74]. In patients with GTD, CT may be helpful in evaluating the extent of extrauterine spread [75].


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Summary of Recommendations Transvaginal and transabdominal US are the most appropriate imaging modalities in patients with abnormal vaginal bleeding in the first trimester of pregnancy. Transvaginal US is generally the preferred modality. Transabdominal US is often complementary to transvaginal US and may sometimes be adequate alone.


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Although there are references that report on studies with design limitations, 6 good-quality studies provide good evidence.


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. Safety Considerations in Pregnant Patients Imaging of the pregnant patient can be challenging, particularly with respect to minimizing radiation exposure and risk. For further information and guidance, see the following ACR documents: ACR Practice Guideline for Imaging Pregnant or Potentially Pregnant Adolescents and Women with Ionizing Radiation [79]


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding. ACR-ACOG-AIUM Practice Guideline for the Performance of Obstetrical Ultrasound [80] ACR Guidance Document for Safe MR Practices [81] ACR Manual on Contrast Media [72]


First Trimester Vaginal Bleeding

First Trimester Vaginal Bleeding


First Trimester Vaginal Bleeding

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