PURPOSE:Shear wave elastography (SWE) is a non-invasive technique for assessing median nerve (MN) stiffness in carpal tunnel syndrome (CTS). This study evaluated whether SWE measurements of the MN improve after corticosteroid injection (CSI) and correlate with symptom improvement in CTS. METHODS:Ten patients (18 wrists) with CTS underwent SWE, grip strength testing, and completed questionnaires before and six weeks after ultrasound-guided CSI. SWE measurements included pressure and velocity in longitudinal/transverse planes at two locations: proximal to and at the carpal tunnel. Progression to carpal tunnel release (CTR) was recorded. Multivariate analyses assessed associations between SWE and symptom scores, controlling for confounders. RESULTS:Functional Status Scale (FSS) and Symptom Severity Scale (SSS) scores improved post-injection (p=0.007 and p<0.001, respectively). Significant changes occurred in SWE carpal tunnel pressure and velocity (p<0.05). No significant association between SWE and CTR progression. Post-injection proximal MN pressure (p=0.005) and velocity (p=0.006) measured longitudinally were associated with FSS scores. CONCLUSION:SWE measurements change with CSI but do not consistently predict symptom relief or surgery need. Questionnaires on daily function and symptoms may be more reliable for outcome tracking.

An os subfibulare is an ossicle that is located distal to the lateral malleolus near the distal fibular tip and typically at the fibular attachment of the anterior talofibular ligament (ATFL). Although there is debate concerning whether these ossicles are unfused accessory ossification centers versus non-united ATFL avulsion fractures, they are seen frequently in the setting of ankle instability. We present a case of an active patient with an unstable os subfibulare contributing to painless "catching" of the ankle due to talar subluxation and locking. This report details the clinical presentation, radiological findings, including MRI and dynamic ultrasound in the "locked" position, and surgical treatment for this unusual presentation of this unstable ossicle. The case underscores the potential importance of the os subfibulare in a patient with ankle instability and highlights the role of advanced imaging in guiding effective treatment.

Pancreas transplant (PT) improves quality of life and longevity in patients with diabetes by restoring endocrine function, eliminating insulin use, and reducing long-term complications. The benefits of PT must be weighed against the risks, including postsurgical complications and long-term immunosuppression. Surgical advances and improved immunosuppression regimens in the past 2 decades have led to improved patient and allograft survival rates. Imaging a PT can be challenging because of the complex postsurgical anatomy and difficulty distinguishing the PT from adjacent bowel, particularly at US. Nevertheless, US is the first-line imaging modality for evaluating the allograft and vasculature for complications. Contrast-enhanced US is a useful next step to evaluate blood flow to the allograft when Doppler US findings are inconclusive. CT with oral contrast material is preferred for evaluating suspected bowel complications and is useful for evaluating fluid collections. CT angiography is a rapid way to evaluate vasculature and bleeding complications if iodinated contrast material is not contraindicated. MRI can be used as a problem-solving tool to further evaluate complications, particularly when iodinated contrast material is contraindicated or radiation risk is a concern. Ferumoxytol-enhanced MRI is advantageous for evaluating transplant vasculature because of the prolonged intravascular state of the contrast material. It is important for radiologists to understand the spectrum of normal imaging appearances of the pancreas allograft, as well as various posttransplant complications, to provide optimal care. The authors discuss surgical techniques and the anatomy of PT, review imaging evaluation, and describe complications. ©RSNA, 2025 Supplemental material is available for this article.

OBJECTIVE:To determine the proportion of cases of lower extremity symptoms attributable to underlying musculoskeletal (MSK) rather than thrombotic etiologies in emergency versus non-emergency settings. METHODS:We retrospectively reviewed all lower extremity Venous Doppler ultrasounds performed on emergency department (ED) and non-ED patients over a 1-year period at a single institution. Using radiology report data mining software, keywords including tear, tendon, hematoma, and muscle were used to identify cases of MSK pathology of the lower leg. All reports were also reviewed for findings of venous thrombosis. Statistical significance between ED and non-ED patients for both incidental MSK pathology and venous thrombosis was assessed using chi-squared tests. RESULTS:A total of 5714 lower extremity Doppler ultrasounds were performed at a single institution during the 1-year period, 1829 in the ED and 3885 in non-ED settings. Sixty-nine of 1829 (3.8%) ED patients had incidental MSK pathology of the lower extremity compared to 53/3885 (1.4%) in the non-ED setting (p < .001). Two hundred sixty-seven of 1829 (14.5%) ED patients had evidence of venous thrombosis and/or chronic post-thrombotic change. When combined with thrombotic pathology as positive cases, incidental MSK injury accounted for 69/336 (20.5%) of ED cases with positive sonographic findings. CONCLUSIONS:MSK pathology of the lower leg is significantly more likely to contribute to lower extremity symptoms in the ED compared to a non-ED setting. Therefore, a brief sonographic evaluation of the MSK apparatus may be beneficial in a subset of ED patients, particularly those with focal pain but no identifiable thrombotic etiology.

Ultrasound-guided injections are safe and effective meth-ods to achieve intra-articular and/or bursal access. This paper reviews common approaches for targeting the hip, knee, ankle, and subtalar joints, as well as the iliopsoas and greater trochanteric bursae. The discussion highlights the critical periarticular and juxta-bursal anatomy to be aware of to optimize the approach and minimize the risk of complications. Tactics to employ during complex and/or technically challenging cases are shared.

ObjectivesTo combine sonographic Murphy sign (SMS) with clinical parameters to effectively stratify patients into risk groups for acute cholecystitis.MethodsConsecutive emergency department patients from April 1, 2019 to August 31, 2022 with possible acute cholecystitis were grouped using patient age, sex, and white blood cell count to determine the rate of acute cholecystitis found in subgroups. Three distinct clinical risk groups were established and then regrouped by prospective assessment of SMS into three non‐imaging risk groups. Differences in the rate of acute cholecystitis for clinical parameters, clinical risk groups, and non‐imaging risk groups were statistically analyzed.ResultsOf 1231 patients (mean [SD] age, 51.2 [19.5]; 476 [38.7%] male), 156 had acute cholecystitis (mean [SD] age, 62.0 [15.4]; 85 [54.5%] male). Rates differed based on sex (9.4% female vs 17.9% male, P < .001), age group (1.8% for patients <30 years, 9.0% for patients 30–59 years, 22.3% for patients ≥60 years; P < .001), and white blood cell count (23.1% elevated vs 6.6% not elevated; P < .001). The low, average, and high non‐imaging risk groups had acute cholecystitis rates of 1.8%, 14.0%, and 43.1%, respectively. Relative risk (95% CI) for the low non‐imaging group compared with others was 0.07 (0.04, 0.12; P < .001); relative risk for the high non‐imaging risk group compared with others was 7.05 (5.32, 9.43; P < .001).ConclusionsSonographic Murphy sign assessment combined with patient age, sex, and white blood cell count effectively stratifies acute care patients into distinct acute cholecystitis risk groups.

The sonographic diagnosis of acute cholecystitis presents challenges. In our practice, we enhance diagnostic accuracy by determining a patient’s risk of acute cholecystitis using four non-image parameters and five imaging parameters. The non-image risk assessment is based on patient age, sex, leukocytosis, and the presence of a sonographic Murphy sign. The imaging risk stratification is derived from evaluating gallbladder (GB) distention, GB wall thickness, GB contents, pericholecystic irregular collections, and hepatic artery peak systolic velocity (HAv). By applying a standardized scoring framework, patients are stratified into one of four diagnostic categories for acute cholecystitis: (1) practically excluded (< 1

BACKGROUND:The authors examined whether ultrasound sensitivity, specificity, and accuracy in identifying intact repairs or flexor tendon gapping after zone 2 repair are affected by the number of suture strands crossing the repair or gap or imaging modality (static versus dynamic). METHODS:A total of 144 fresh-frozen cadaveric digits (thumbs excluded) were randomized to either an intact repair (0-mm gap) or simulated failed repair (4-mm gap), as well as to either a two- or eight-strand locked-cruciate repair of a zone 2 flexor digitorum profundus tendon laceration using 4-0 Fiberwire. Examinations were performed by a blinded musculoskeletal ultrasonographer in static and dynamic modes using an 18-MHz transducer. Gaps were remeasured after scanning, and the final gap width recorded. McNemar exact test was used to determine whether there were differences in sensitivity, specificity, and accuracy affected by modality (static versus dynamic), and chi-square test was used to compare sensitivity, specificity, and accuracy between number of strands (two versus eight) crossing the intact repair or repair gap (≥4 mm). RESULTS:Sensitivity, specificity, and accuracy improved with increased number of suture strands crossing the repair or gap (eight versus two), irrespective of modality (static versus dynamic), and dynamic compared with static scanning modes, irrespective of number of suture strands crossing the repair or gap site. CONCLUSIONS:The most sensitive and accurate means of assessing flexor tendon repair integrity and gapping were seen using the dynamic scanning mode. Increased number of suture strands did not negatively affect sensitivity, specificity, or accuracy, regardless of scanning mode (dynamic or static).

Compare HAv to non-Doppler ultrasound observations for diagnosing acute cholecystitis in a large consecutive cohort of emergency department (ED) patients and establish a method to combine HAv assessment with non-Doppler observations for diagnosing acute cholecystitis. Consecutive ED patients at one institution undergoing gallbladder (GB) ultrasound (US) for acute cholecystitis between 1/1/2020 and 8/31/2022 had assessments of GB diameter, GB wall thickness, GB contents, pericholecystic irregular collection, and hepatic artery peak systolic velocity (HAv). The non-Doppler observations were scored and summed. Non-Doppler risk categorization was based on rate of acute cholecystitis associated with summed scores. The impact of HAv stratification on the rate of acute cholecystitis in the non-Doppler risk categories was evaluated, with regrouping when subgroups had changes in the acute cholecystitis rate; the regrouping established the HAv-adjusted risk model. Receiver-operator curves for acute cholecystitis diagnosis for individual parameters, the non-Doppler risk categorization, and the HAv-adjusted risk model were compared using area-under-curve (AUC) calculations. Of the 885 patients in the study cohort, 117 (13.2

Ultrasound (US) is the imaging modality of choice for evaluation of superficial palpable lesions. A large proportion of these lesions have characteristic sonographic appearance and can be confidently diagnosed with US without the need for biopsy or other intervention. The Society of Radiologists in Ultrasound (SRU) recently published a Consensus Conference Statement on superficial soft tissue masses. The goal of this manuscript is (a) to serve as a sonographic pictorial review for palpable lesions based on the SRU statement, (b) present the typical sonographic features of palpable lesions that can be confidently diagnosed with US, and (c) provide an overview of other palpable lesions with a framework to interpret the US studies and advise on appropriate further management.

Gallbladder (GB) polyps are a common incidental finding on sonography, but only a small fraction of polyps become GB cancer. The Society of Radiologists in Ultrasound (SRU) consensus committee recently performed an extensive literature review and published guidelines for GB polyp follow-up/management to provide clarity among the many heterogeneous recommendations that are available to clinicians. As these guidelines have become adopted into clinical practice, challenging clinical scenarios have arisen including GB polyps in primary sclerosing cholangitis (PSC), high risk geographic/genetic patient populations, shrinking polyps, pedunculated vs sessile polyps, thin vs thick stalked polyps, vascular polyps and multiple polyps. According to the SRU guidelines, clinicians should refer to gastroenterology guidelines when managing GB polyps in patients with known PSC. If patients at high geographic/genetic risk develop GB polyps, ‘extremely low risk’ polyps may be managed as ‘low risk’ and 10–14 mm ‘extremely low risk’ or ‘7–14 mm’ low risk polyps that decrease in size by ≥ 4 mm require no follow-up. Thin-stalked or pedunculated polyps are ‘extremely low risk’ and thick-stalked pedunculated polyps are ‘low risk’. Sessile polyps are ‘low risk’ but should receive immediate specialist referral if features suggestive of GB cancer are present. Neither polyp multiplicity nor vascularity impact risk of GB cancer and follow up should be based on morphology alone.

Objectives Early, accurate diagnosis is crucial for the prognosis of patients with soft tissue sarcomas. To this end, standardization of imaging algorithms, technical requirements, and reporting is therefore a prerequisite. Since the first European Society of Musculoskeletal Radiology (ESSR) consensus in 2015, technical achievements, further insights into specific entities, and the revised WHO-classification (2020) and AJCC staging system (2017) made an update necessary. The guidelines are intended to support radiologists in their decision-making and contribute to interdisciplinary tumor board discussions. Materials and methods A validated Delphi method based on peer-reviewed literature was used to derive consensus among a panel of 46 specialized musculoskeletal radiologists from 12 European countries. Statements were scored online by level of agreement (0 to 10) during two iterative rounds. Either “group consensus,” “group agreement,” or “lack of agreement” was achieved. Results Eight sections were defined that finally contained 145 statements with comments. Overall, group consensus was reached in 95.9%, and group agreement in 4.1%. This communication contains the first part consisting of the imaging algorithm for suspected soft tissue tumors, methods for local imaging, and the role of tumor centers. Conclusion Ultrasound represents the initial triage imaging modality for accessible and small tumors. MRI is the modality of choice for the characterization and local staging of most soft tissue tumors. CT is indicated in special situations. In suspicious or likely malignant tumors, a specialist tumor center should be contacted for referral or teleradiologic second opinion. This should be done before performing a biopsy, without exception. Clinical relevance The updated ESSR soft tissue tumor imaging guidelines aim to provide best practice expert consensus for standardized imaging, to support radiologists in their decision-making, and to improve examination comparability both in individual patients and in future studies on individualized strategies. Key Points • Ultrasound remains the best initial triage imaging modality for accessible and small suspected soft tissue tumors. • MRI is the modality of choice for the characterization and local staging of soft tissue tumors in most cases; CT is indicated in special situations. Suspicious or likely malignant tumors should undergo biopsy. • In patients with large, indeterminate or suspicious tumors, a tumor reference center should be contacted for referral or teleradiologic second opinion; this must be done before a biopsy.

Marjolin's ulcer is a cutaneous malignancy that arises from previously damaged skin, long-standing scars, chronic wounds such as burns, chronic venous ulcers, pressure ulcers, chronic osteomyelitis, or sinuses. Burn scars are the most common lesion leading to this malignancy. Marjolin's ulcer affects 1% to 2% of all burn scars. We present a case of Marjolin's ulcer occurring in an old burn scar in a 46-year-old female, focusing on the high-resolution ultrasound features and its role in its management. Ultrasound was found to be helpful not only in evaluating the extent and depth of the lesion, but also in indicating the likelihood of malignant transformation. Histopathology confirmed it to be a squamous cell carcinoma. A wide excision with skin grafting was done. To the best of our knowledge, there is no literature reporting the ultrasound evaluation and findings of Marjolin's ulcer.

Colectomy for ulcerative colitis can be followed by ileal pouch formation to enable restoration of bowel continuity. Patients with familial adenomatous polyposis may also undergo pouch formation. The most common long-term problem with pouches is pouchitis, though this can often be treated with antibiotics. Stomas come in many forms but the most common types are ileostomy or colostomy, both of which can be permanent or temporary. The indications and complications of each are discussed. The expertise of a stoma nurse is vital to the management of these patients.

Journal of Ultrasound in MedicineEarly View Practice ParameterFree Access The AIUM Practice Parameter for the Performance of the Extended Focused Assessment With Sonography for Trauma (EFAST) First published: 10 June 2022 https://doi.org/10.1002/jum.16027AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Introduction The American Institute of Ultrasound in Medicine (AIUM) is a multidisciplinary association dedicated to advancing the safe and effective use of ultrasound in medicine through professional and public education, research, development of clinical practice parameters, and accreditation of practices performing ultrasound examinations. The AIUM practice parameter for the performance of the extended focused assessment with sonography for trauma (EFAST) was developed and revised by the AIUM in collaboration with other organizations whose members use ultrasound for performing this diagnostic test (see “Acknowledgments”). Recommendations for personnel requirements, the request for the examination, documentation, quality assurance, and safety may vary among the organizations and may be addressed by each separately. This practice parameter is intended to provide the medical ultrasound community with recommendations for the performance and recording of high-quality ultrasound examinations. The parameters reflect what the AIUM considers the appropriate criteria for this type of ultrasound examination but are not intended to establish a legal standard of care. Examinations performed in this specialty area are expected to follow the parameter with recognition that deviations may occur depending on the clinical situation. This practice parameter has been developed to provide assistance to practitioners performing EFAST. During the last 3 decades, particularly with its widespread growth in the early 1990s, the FAST included assessments of the peritoneal cavity, and analysis of the pericardial and pleural spaces for hemorrhage. In the early 2000s, the extended FAST (EFAST) added rapid evaluation of the chest for detection of pneumothorax, and this more thorough trauma examination is taught and used in standard practice today. The EFAST is a diagnostic test of information not otherwise obtained by physical examination. The EFAST is a proven and useful diagnostic test for the evaluation of the torso and abdomen after traumatic injury, particularly in the setting of hemodynamic instability. The examination has been shown to be highly specific, with varying sensitivity, in the identification of free intraperitoneal and intrathoracic fluid. Evidence indicates that ultrasound imaging is more sensitive for pneumothorax than supine plain-film chest radiography. It is important to note that the EFAST examination is a screening test, and false-negative examinations may occur, particularly early in the course of management. False-positive examinations for free fluid may also be encountered in patients with a history of ascites, those receiving peritoneal dialysis, and patients with concurrent pleural effusions. Before its development, more invasive procedures were required to evaluate these patients, including diagnostic peritoneal lavage and, at times, laparotomy. In the management of the trauma patient, adherence to the following parameter will maximize the probability of detecting free fluid in the acutely injured patient. The EFAST allows the analysis for possible hemopericardium, hemothorax, pneumothorax, and hemoperitoneum. The portability of ultrasound equipment allows the EFAST to be performed at the patient's bedside or in the rapid triaging of multiple individuals in mass casualty situations, including assessments in the field. Emergency medical services personnel have begun to use EFAST in several areas worldwide for these purposes. The use of ultrasound in a particular institution or setting must be based on access to equipment and appropriately trained or supervised personnel, and should be subject to an organized quality assurance program. Indications Indications for the EFAST primarily evaluate the torso and abdomen for evidence of traumatic injury in the peritoneal, pericardial, and pleural cavities (American College of Emergency Physicians [ACEP] guideline/ACEP Imaging Compendium). There are no absolute contraindications, although if it is clear that the patient requires emergent surgical intervention, then a relative contraindication to performing the test may exist. For example, it still may be necessary to exclude pericardial tamponade or pneumothorax before transferring a patient to the operating room for emergent surgery. Qualifications and Responsibilities of Personnel Physicians interpreting or performing this type of ultrasound examination should meet the specified AIUM Training Guidelines in accordance with AIUM accreditation policies. Sonographers performing the ultrasound examination should be appropriately credentialed in the specialty area in accordance with AIUM accreditation policies. Physicians not personally performing the examination must provide supervision, as defined by the Centers for Medicare and Medicaid Services Code of Federal Regulations 42 CFR §410.32. The EFAST examination provides information to aid in decision-making regarding further evaluation or testing, clinical management, and therapeutic interventions. Rapid provision and interpretation of such examinations are critical for appropriate patient care. The clinical care of patients in life-threatening situations should always take precedence over these guidelines. Physicians from a variety of medical specialties may perform the EFAST examination. If appropriately trained, advanced practice providers, emergency medical personnel, and sonographers can obtain the ultrasound images. Image interpretation should be performed by a supervising physician. Training of physicians in the diagnostic interpretation of EFAST examinations should be in accordance with specialty-specific guidelines. Physicians who supervise nonphysician sonographers should render a diagnostic interpretation in a time frame consistent with the management of acute trauma. Specification of the Examination The objective of the abdominal portion of the diagnostic study is to analyze the peritoneal cavity for free fluid. This requires examination of the abdomen (right upper and left upper quadrants as well as the pelvis), the pericardium, and if performing an EFAST, the bilateral pleura in the thorax. The ability to denote free fluid in the pelvis is aided by the presence of a fluid-filled bladder. As with all ultrasound examinations, orthogonal images (transverse, longitudinal, and coronal planes) help elucidate areas of concern seen in any single plane, and all areas of interest should be scanned through completely using a fanning motion in each plane. Changes in transducer angle and position can help improve analysis of a given area. Images may be obtained through anterior, lateral, or other approaches to denote free fluid in the evaluated areas. As with most imaging and ultrasound examinations, techniques evolve over time and with increased clinical and imaging experience. More specifically, primary ultrasound windows for the EFAST include the following: The Right Upper Quadrant View (also known as the Perihepatic, Morison Pouch, or Right Flank View)—This uses the liver as an ultrasound window to interrogate the hepatorenal space (Morison Pouch) for free fluid. The transducer is placed in a coronal orientation on the patient's right side with the probe marker pointed toward the patient's head. Slight cephalad movement of the transducer allows imaging of the right pleural space for free fluid. Care should be taken to carefully insonate the area between the dome of the liver and diaphragm to identify subdiaphragmatic free fluid. Caudal probe movement allows visualization of the inferior pole of the right kidney, the caudal liver tip, and right pericolic gutter for free fluid assessment. The transducer should be fanned throughout the anterior and posterior directions to interrogate the entire field. The Left Upper Quadrant View (also known as the Perisplenic or Left Flank View)—This uses the spleen as a window to interrogate the spleen and the perisplenic space above the spleen, below the diaphragm, and the splenorenal recess. The transducer is placed in a coronal orientation on the patient's posterior left side, with the probe marker pointed toward the patient's head. Scanning cephalad allows visualization of the left pleural space. Scanning caudad allows visualization of the inferior pole of the left kidney, the caudal spleen tip, and the left pericolic gutter. Again, the transducer should be fanned throughout the anterior–posterior space to interrogate the entire field. The Pleural Space Views—Each pleural space may be investigated via angulation and cephalad movement of the transducer along the ipsilateral flank. This can be performed in conjunction with the right and left upper quadrant views. Abnormal fluid collections in the pleural space are visualized as anechoic collections above the echogenic diaphragm. Visualization of the thoracic spine (a “spine sign”) also indicates fluid or consolidation in the pleural space. At times, fluid that may be hemorrhagic, proteinaceous, or infectious will appear more echogenic or complex in nature. An upright or slight reverse Trendelenburg position of the patient may assist in the detection of pleural fluid. The Pelvic View (also known as the Retrovesical, and for female patients: Retrouterine, or Pouch of Douglas View)—This allows assessment of the most dependent space in the peritoneum for free fluid. Analysis through a fluid-filled bladder (which can be filled, if necessary, by fluid placed through a Foley catheter or clamping the Foley catheter) may help analysis for pelvic fluid. When free fluid is present, it is noted most often posterior or superior to the bladder and uterus in adults. The bladder should be scanned in its entirety in both the sagittal and transverse planes. The Pericardial View (also known as the Subcostal or Subxiphoid View)—Subxiphoid images can be obtained by placing the transducer on the upper abdomen and pointing superiorly midline or toward the left shoulder using the liver as an acoustic window. Alternative cardiac windows can be additive or may be necessary if an adequate subxiphoid view cannot be obtained in a particular patient. The parasternal long-axis view of the heart is typically the next most common view used; however, other views, including the apical 4-chamber, may be used, as long as the pericardium can be assessed circumferentially. The potential space of the pericardium is analyzed for the presence of any free fluid in anterior or posterior locations. The presence of free fluid prompts assessment for tamponade. The Anterior Thoracic View (Pleural Sliding Views)—The pleura normally oppose each other and slide against each other easily. The separation of the pleura by a pneumothorax and subsequent absence of this sliding may be imaged typically in a supine patient in the second or third intercostal space with a high-frequency transducer, although lower-frequency transducers may also be used. Other intercostal spaces may also be used for lung evaluation. Pleural sliding with reverberation artifacts (A-lines) is present in the normal lung. M-mode imaging may aid in the evaluation of the lung for pneumothorax. The identification of a lung point is highly specific for the diagnosis of pneumothorax and should be sought when time allows. A lung point represents the site where the lung adheres to the parietal pleura immediately adjacent to the pneumothorax. A lung pulse (subtle cardiac pulsation of the parietal pleura at the lung periphery) can differentiate the lack of ventilation, such as in apnea or main stem intubation, from pneumothorax. Additional dedicated views may include the following: The Right and Left Pericolic Gutter Views—Longitudinal and transverse views through peritoneal windows inferior to the level of the ipsilateral kidney and next to the ipsilateral iliac crest may reveal free fluid surrounding the bowel. These windows may be of limited use because of the absence of an acoustic window, such as a fluid-filled bladder or a solid organ. Air-filled bowel may also limit these views. The presence of larger amounts of fluid may aid in visualization. The images may be obtained laterally or from an anterior approach. The Parasternal View—The parasternal window allows visualization of the heart in the long or short axis. This view may be used when a patient's subcostal view is suboptimal. The Apical View—The apical view may allow visualization of pericardial fluid by placing the transducer around the nipple line at the left fifth intercostal space. This view may also be used when the subcostal view is not optimal. Supplemental views: Inferior Vena Cava (IVC) Views—Multiple views of the IVC are accessible by using either a subxiphoid or lateral approach. The lateral approach makes use of the liver as an acoustic window. The primary aim of IVC evaluation is to aid in the assessment of the intravascular volume status. IVC evaluation is particularly useful in those patients at the extreme ends of the spectrum: either hypovolemic (eg, secondary to massive hemorrhage) or severely fluid overloaded. Dynamic IVC evaluation has also been shown to be useful in assessing patients' response to volume resuscitation or transfusion of blood products. Other Considerations for the EFAST Examination Include the Following Points Trendelenburg positioning may increase the sensitivity of the ultrasound examination for visualizing free fluid in the right upper quadrant or left upper quadrant. Semi-Fowler positioning may increase the sensitivity of detection of a pneumothorax in the apical lung zones and detection of hemothorax at the lung bases. An EFAST examination is not designed to be performed only once, and it may be repeated during the patient's stay for reassessment of the patient's condition either routinely or as a consequence of clinical decompensation. As a caveat, one must remember that trauma ultrasound provides a picture of a patient's condition at one moment in time. It does not eliminate the possibility of injury or fluid collections that are below detectable thresholds. Acute hemorrhage appears as anechoic fluid collections described previously in this document. However, as the blood clots, fluid collections may appear complex, hypoechoic, or even isoechoic to surrounding structures. In some cases, areas within dense structures that are actively bleeding may appear hyperechoic to surrounding tissues. Contrast-enhanced ultrasound (CEUS) can be utilized in combination with the EFAST exam in the evaluation for solid organ injury in patients with abdominal trauma. There are currently 3 FDA-approved ultrasound contrast agents, but CEUS in EFAST exams is not widespread and the use of contrast media may be off-label for certain views. It is only mentioned here to bring awareness of this application. Providing recommendations for the use of CEUS is not within the scope of these practice parameters. For more information, please refer to the AIUM Practice Parameter for the Performance of Contrast-Enhanced Ultrasound Examinations.1, 2 Limitations There are limitations to EFAST assessments, including reduced ability to detect free fluid in children or exact locations of injury to mesenteric structures, diaphragm, bowel, or solid organs. The EFAST is also limited in identifying retroperitoneal hemorrhage, although injuries can at times be seen. The potential false-positive diagnosis of free traumatic fluid in the peritoneum may be due to fluid present in patients for physiologic reasons, including ruptured ovarian cyst, as well as pathologic reasons, such as patients with ascites or inflammatory processes in the abdomen or pelvis. One must also be aware that free fluid is typically present intraperitoneally in patients with ventriculoperitoneal shunts, in those who undergo peritoneal dialysis, and in those after recent peritoneal lavage and surgery. It can be difficult to identify free fluid in patients with severe polycystic kidney or ovarian disease. Additionally, perinephric fat may also be mistaken for free fluid. Ultrasound may also be technically limited in the trauma patient due to bowel gas, obesity, subcutaneous or peritoneal emphysema, patient positioning, the degree of injury and rate of bleeding, adhesions from prior surgery, and often in patients who are either in pain or combative secondary to traumatic injury. Like many diagnostic ultrasound examinations, the main limitation of the EFAST is that the operator must be knowledgeable in its clinical use and limitations, and be aware that a negative EFAST does not exclude all injuries. Limitations to the pericardial assessment for hemopericardium include pericardial fat pads, cysts, and preexisting pericardial fluid. Limitations to pleural assessment for hemothorax include pleural fluid from preexisting pleural disease as well as extension of fluid into the pleural space from the pericardium or peritoneum. Finally, the limitations in the evaluation for pneumothorax include mistaking the absence of pleural sliding after a mainstem bronchus intubation for a pneumothorax as well as failure to recognize the associated presence of a lung pulse, and false-positive examinations after pleurodesis or in patients with severe chronic obstructive pulmonary disease. Other lung or chest wall pathologies may inhibit adequate visualization of pleural sliding. Although the sensitivity in the detection of pneumothorax is very high, it is important to note that small apical, mediastinal, non-pleural-based, or localized pneumothoraces may not be visualized in a focused thoracic ultrasound examination. Further information may be obtained by referring to the ACEP Emergency Ultrasound Imaging Criteria Compendium—Trauma.3 Documentation Accurate and complete documentation is essential for high-quality patient care. Written reports and ultrasound images/video clips that contain diagnostic information should be obtained and archived, with recommendations for follow-up studies if clinically applicable, in accordance with the AIUM Practice Parameter for Documentation of an Ultrasound Examination. The diagnostic interpretation of findings in an EFAST examination is limited to those areas assessed and imaged. In particular, an EFAST analysis does not allow the diagnostic evaluation of all abnormalities in the chest, abdomen, or pelvis. A guide for documentation may also be found in the ACEP standard reporting guidelines.4 Equipment Specification The EFAST examination may be conducted with any device that provides diagnostic quality. The equipment should be adjusted to operate at the highest clinically appropriate frequency, realizing that there is a trade-off between resolution and beam penetration. For most preadolescent pediatric patients, transducers with a smaller footprint (including phased array transducers) are preferred. In neonates and small infants, a higher-frequency transducer may be necessary. For adults, mean frequencies of 3.5 and 5 MHz are most commonly used. Occasionally, very large patients may require a lower frequency such as 2 MHz for analysis. Quality and Safety Policies and procedures related to quality assurance and improvement, safety, infection control, and equipment performance monitoring should be developed and implemented in accordance with the AIUM Standards and Guidelines for the Accreditation of Ultrasound Practices. ALARA (As Low as Reasonably Achievable) Principle The potential benefits and risks of each examination should be considered. The ALARA principle should be observed for factors that affect the acoustical output and by considering transducer dwell time and total scanning time. Further details on ALARA may be found in the current AIUM publication Medical Ultrasound Safety. Infection Control Transducer preparation, cleaning, and disinfection should follow manufacturer recommendations and be consistent with the AIUM Guidelines for Cleaning and Preparing External- and Internal-Use Ultrasound Transducers Between Patients, Safe Handling, and Use of Ultrasound Coupling Gel. Equipment Performance Monitoring Monitoring protocols for equipment performance should be developed and implemented in accordance with the AIUM Standards and Guidelines for the Accreditation of Ultrasound Practice. Policies and procedures related to image quality, equipment performance monitoring, infection control, and patient safety as well as patient education with regard to the EFAST should be developed and implemented in accordance with either the AIUM Standards and Guidelines for the Accreditation of Ultrasound Practices or the guidelines developed by specialty specific organizations such as the ACEP. Acknowledgments This parameter was developed by the AIUM in collaboration with the American College of Emergency Physicians (ACEP). We are indebted to the many volunteers who contributed their time, knowledge, and energy to developing this document. Collaborative Subcommittees AIUM Rachel Liu, MD Vivek Tayal, MD, FACEP, FAIUM Nova Panebianco, MD MPH Daniel Theodoro, MD MSCI Penelope Lema, MD ACEP Elaine Situ-LaCasse, MD Michael Gottlieb, MD AIUM Expert Advisory Group Alyssa Abo, MD AIUM Clinical Standards Committee James M. Shwayder, MD, JD, chair Rachel Bo-ming Liu, MD, vice chair Creagh T. Boulger, MD Bryann Bromley, MD Nirvikar Dahiya, MD John R. Eisenbrey, PhD Rob Goodman, MBBCh, MBA, BMSc Ethan J. Halpern, MD Oliver Daniel Kripfgans, PhD Jean Spitz, MPH, CAE, RDMS John Stephen Pellerito, MD Margarita Revzin, MD Original copyright 2007; Revised 2014, 2022 References 1AIUM practice parameter for the performance of contrast-enhanced ultrasound examinations. J Ultrasound Med 2020; 39: 421– 429. Wiley Online LibraryPubMedWeb of Science®Google Scholar 2Zhang Z, Hong Y, Liu N, Chen Y. 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Contrast-enhanced US (CEUS), similar to other radiologic modalities, requires specific technical considerations and is subject to image artifacts. These artifacts may affect examination quality, negatively impact diagnostic accuracy, and decrease user comfort when using this emerging technique. Some artifacts are related to commonly known gray-scale US artifacts that can also appear on the contrast-only image (tissue-subtracted image obtained with the linear responses from background tissues nulled). These may include acoustic shadowing and enhancement; reverberation, refraction, and reflection; and poor penetration. Other artifacts are exclusive to CEUS owing to the techniques used for contrast mode image generation and the unique properties of the microbubbles that constitute ultrasound-specific contrast agents (UCAs). UCA-related artifacts may appear on the contrast-only image, the gray-scale image, or various Doppler mode images. Artifacts related to CEUS may include nonlinear artifacts and unintentional microbubble destruction resulting in pseudowashout. The microbubbles themselves may result in specific artifacts such as pseudoenhancement, signal saturation, and attenuation and shadowing and can confound the use of color and spectral Doppler US. Identifying and understanding these artifacts and knowing how to mitigate them may improve the quality of the imaging study, increase user confidence, and improve patient care. The authors review the principles of UCAs and the sound-microbubble interaction, as well as the technical aspects of image generation. Technical considerations, including patient positioning, depth, acoustic window, and contrast agent dose, also are discussed. Specific artifacts are described, with tips on how to identify and, if necessary, apply corrective measures, with the goal of improving examination quality. © RSNA, 2022 Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Adenomyomatosis and cholesterolosis of the gallbladder, collectively termed hyperplastic cholecystosis, are commonly encountered incidental findings on imaging studies performed for a variety of indications including biliary colic or nonspecific abdominal pain. These pathologies are rarely the source of symptoms, generally considered benign and do not require further work-up. However, their imaging characteristics can overlap with more sinister conditions that should not be missed. In this review, the imaging findings of adenomyomatosis and cholesterolosis will be reviewed followed by other gallbladder pathologies that might mimic these conditions radiologically. Important differentiating factors will be discussed that can aid the radiologist in making a more confident imaging diagnosis.

Chronic venous insufficiency is a common condition caused by valvular incompetence and/or obstruction of the lower extremity venous system. Chronic venous insufficiency presents in a wide range of clinical presentations, ranging from mild pain or edema to the development of varicose veins and nonhealing venous ulcers. Doppler ultrasound is the preferred imaging modality in the assessment of this condition and provides both anatomical and functional information in a noninvasive, cost-effective, and radiation-free manner. Knowledge of the anatomy and nomenclature, pathophysiology, equipment requisites, scanning protocols, relevant findings, and reporting nuances is essential to the creation of an accurate and clinically actionable report. Evaluation of the superficial and deep venous system for degree and extent of reflux is necessary to establish the diagnosis and to institute appropriate treatment.