External Validation of O-RADS US Risk Stratification and Management System.

Background The Ovarian-Adnexal Reporting and Data System (O-RADS) US risk stratification and management system (O-RADS US) was designed to improve risk assessment and management of ovarian and adnexal lesions. Validation studies including both surgical and nonsurgical treatment as the reference standard remain lacking. Purpose To externally validate O-RADS US in women who underwent either surgical or nonsurgical treatment and to determine if incorporating acoustic shadowing as a benign finding improves diagnostic performance. Materials and Methods This retrospective study included consecutive women who underwent pelvic US between August 2015 and April 2017 at a tertiary referral oncology center. Two independent readers blinded to clinical and histologic outcome assigned an O-RADS risk category and an International Ovarian Tumor Analysis (IOTA) Assessment of Different NEoplasias in the adneXa (ADNEX) model risk of malignancy score to assessable lesions. Reference standards were surgical histopathology or 2-year imaging follow-up. Receiver operating characteristic (ROC) curve analysis was used to evaluate performance of the O-RADS US, ADNEX, and modified O-RADS models incorporating acoustic shadowing. Results In total, 227 women (mean age, 52 years ± 16 [SD]) with 262 ovarian or adnexal lesions were evaluated. Of these lesions, 187 (71%) were benign and 75 (29%) were malignant. The proportion of malignancy was 0% (0 of 100) for O-RADS 2, 3% (one of 32) for O-RADS 3, 35% (22 of 63) for O-RADS 4, and 78% (52 of 67) for O-RADS 5. The area under the ROC curve (AUC) for O-RADS and ADNEX was 0.91 (95% CI: 0.88, 0.94) and 0.95 (95% CI: 0.92, 0.97; P = .01), respectively. The addition of acoustic shadowing as a benign finding improved O-RADS AUC to 0.94 (95% CI: 0.91, 0.96; P = .01). Use of O-RADS 4 as a threshold yielded a sensitivity of 99% (74 of 75; 95% CI: 96, 100) and a specificity of 70% (131 of 187; 95% CI: 64, 77). Conclusion In a tertiary referral oncology center, the Ovarian-Adnexal Reporting and Data System US risk stratification and management system enabled accurate distinction of benign from malignant ovarian and adnexal lesions. Adding acoustic shadowing as a benign finding improved its diagnostic performance. © RSNA, 2022 See also the editorial by Levine in this issue.

O-RADS for Ultrasound: A User's Guide, From the AJR Special Series on Radiology Reporting and Data Systems.

The Ovarian-Adnexal Reporting and Data System (O-RADS) is a lexicon and risk stratification tool designed for the accurate characterization of adnexal lesions and is essential for optimal patient management. O-RADS is a recent addition to the American College of Radiology (ACR) reporting and data systems and consists of ultrasound (US) and MRI arms. Since most ovarian or adnexal lesions are first detected with US, O-RADS US is considered the primary assessment tool. Application of O-RADS US is recommended whenever a nonphysiologic lesion is encountered. Lesion characterization may be streamlined by use of an algorithmic approach focused on relevant features and an abbreviated version of the lexicon. Resources to expedite O-RADS US categorization and determination of a management recommendation include easy online access to the ACR color-coded risk stratification scorecards and an O-RADS US calculator that is available as a smartphone app. Reporting should be concise and include relevant features for risk stratification that adhere to lexicon terminology. Technical considerations include optimization of gray-scale and color Doppler technique and performance of problem-solving maneuvers to help avoid common pitfalls. This review provides a user-friendly summary of O-RADS US with practical tips for everyday clinical use.

Primary perivascular epithelioid cell tumors of the liver: CT/MRI findings and clinical outcomes.

OBJECTIVES: The purpose of our study was to describe the CT and MRI features of primary PEComas of the liver and to document the associated clinical outcomes. METHODS: Retrospective study included 20 patients with primary hepatic perivascular epithelioid cell tumors (PEComa) with pathology and clinical outcomes for correlation. RESULTS: Study group included 20 patients: 16 women, 4 men; mean age 53 (range 35-77) years. Initial pathology diagnoses were classic angiomyolipoma (AML) (n = 11), epithelioid AML (n = 7), and PEComa not otherwise specified (n = 2). Mean tumor size was 5.1 (range 1.3-15.0) cm. CT/MRI features included well-defined margins 20/20 (100%), arterial enhancement 18/19 (95%), subcapsular location 17/20 (85%), heterogeneous 16/20 (80%), dysmorphic vessels 14/20 (70%), fat 13/20 (65%), hemorrhage 4/20 (20%), cystic components 4/20 (20%), and calcification 1/20 (5%). At the time of discovery, 18 patients were asymptomatic and their tumors were incidentally detected on imaging, and 2 patients were symptomatic. Ultimately, 18 tumors were benign and 2 developed metastases. CONCLUSIONS: On CT/MRI, most primary hepatic PEComas were well-defined, arterial enhancing, subcapsular, heterogeneous masses that often had dysmorphic vessels and contained fat. Most tumors were benign but complications included local symptoms, bleeding, and malignant change.

CT following US for possible appendicitis: anatomic coverage.

OBJECTIVE: To determine superior-inferior anatomic borders for CT following inconclusive/nondiagnostic US for possible appendicitis. METHODS: Ninety-nine patients with possible appendicitis and inconclusive/nondiagnostic US followed by CT were included in this retrospective study. Two radiologists reviewed CT images and determined superior-inferior anatomic borders required to diagnose or exclude appendicitis and diagnose alternative causes. This "targeted" coverage was used to estimate potential reduction in anatomic coverage compared to standard abdominal/pelvic CT. RESULTS: The study group included 83 women and 16 men; mean age 32 (median, 29; range 18-73) years. Final diagnoses were: nonspecific abdominal pain 50/99 (51%), appendicitis 26/99 (26%), gynaecological 12/99 (12%), gastrointestinal 9/99 (10%), and musculoskeletal 2/99 (2%). Median dose-length product for standard CT was 890.0 (range, 306.3 - 2493.9) mGy.cm. To confidently diagnose/exclude appendicitis or identify alternative diagnoses, maximum superior-inferior anatomic CT coverage was the superior border of L2-superior border of pubic symphysis, for both reviewers. Targeted CT would reduce anatomic coverage by 30-55% (mean 39%, median 40%) compared to standard CT. CONCLUSIONS: When CT is performed for appendicitis following inconclusive/nondiagnostic US, targeted CT from the superior border of L2-superior border of pubic symphysis can be used resulting in significant reduction in exposure to ionizing radiation compared to standard CT. KEY POINTS: • When CT is used following inconclusive/ nondiagnostic ultrasound, anatomic coverage can be reduced. • CT from L2 to pubic symphysis can be used to diagnose/exclude appendicitis. • Reduced anatomic coverage for CT results in reduced exposure to ionizing radiation.

Guide to surgical procedures on hollow viscera: part 1--Esophageal, gastric, and restrictive bariatric procedures.

OBJECTIVE: The objective of this article is to explore with a surgical perspective the key radiologic features after common esophageal, gastric, and bariatric procedures. CONCLUSION: An understanding of procedures on the hollow viscera is essential for radiologists at any level. The ability to quickly recognize postoperative anatomy is critical to accurately and efficiently interpret routine imaging studies and to diagnose postoperative complications.

Guide to surgical procedures on hollow viscera: part 2--Colorectal, ostomy, and malabsorptive bariatric procedures.

OBJECTIVE: The objective of this article is to explore with a surgical perspective the key radiologic features of common bariatric, colorectal, and ostomy procedures. The images and diagrams show relevant postoperative anatomy. CONCLUSION: An understanding of procedures on the hollow viscera is essential for a radiologist at any level. The ability to quickly recognize postoperative anatomy is critical to accurately and efficiently interpret routine imaging studies and to diagnose postoperative complications.

Detection of urothelial tumors: comparison of urothelial phase with excretory phase CT urography--a prospective study.

PURPOSE: To compare contrast material-enhanced computed tomographic (CT) urography 60 seconds after injection of contrast material (urothelial phase [UP]) after intravenous administration of a diuretic with the standard 5-minute delayed excretory phase (EP) in a high-risk population for upper tract tumors. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. Eighty CT urographic examinations in 77 patients known to have or at high risk for urothelial malignancy were included. After intravenous administration of a diuretic, dual-phase CT urography was performed at 60 seconds (UP) and 5 minutes (EP) after intravenous administration of contrast material. Two experienced abdominal radiologists independently interpreted each phase more than 1 month apart to minimize recall bias. Urinary tract distention and location and size of all lesions suspected of being urothelial tumors were recorded. Standard of reference was obtained from prospective study interpretation and surgical histopathologic findings. Generalized estimating equations for logistic regression were used to compare performance measures and adjust for the correlation of repeated measures within patients. RESULTS: There were 23 upper and 61 lower urinary tract tumors confirmed in 15 and 32 patients, respectively. For detection of bladder tumors, there was higher sensitivity for the UP than the EP (89.3% [109 of 122] vs 70.5% [86 of 122], respectively; P<.0001). For detection of upper tract tumors, there was higher sensitivity for the UP than the EP (82.6% [38 of 46] vs 69.6% [32 of 46], respectively; P=.0194). Distention of all upper urinary tract segments was better during the EP than the UP (P<.0001). CONCLUSION: UP CT urography after injection of a diuretic has a higher lesion detection rate than the EP for both upper and lower urinary tract tumors, which suggests its possible use as a single-phase protocol for evaluation of the entire urinary tract in patients at high risk for urothelial tumors.

The role of cross-sectional imaging in male infertility: a pictorial review.

Infertility is a common problem. The role of imaging in assisting clinical evaluation is discussed. Ultrasound and magnetic resonance imaging are first-line, noninvasive imaging techniques that provide accurate definition of anatomical causes of infertility. This affords an opportunity to deliver timely and appropriate treatment. This pictorial review illustrates normal imaging anatomy and various causes of male infertility, and focuses on congenital and acquired testicular abnormalities and post-testicular obstruction, such as congenital absence of the vasa deferentia, seminal vesicle cysts, prostatic utricle cysts, Mullerian cysts, ejaculatory duct cysts (Wolffian cysts), and epididymal obstruction.

Renal cortical lesions in patients with autoimmune pancreatitis: a clue to differentiation from pancreatic malignancy.

AIM: To describe the occurrence of renal cortical lesions (RCLs) in patients with autoimmune pancreatitis (AIP). METHODS: This retrospective study was approved by our research ethics board; informed consent was waived. Systematic search of CT scan reports in 5-year interval yielded 17 patients with AIP (male:female; 11:6, age 18-80 years). A consecutive group of 22 patients with pancreatic adenocarcinoma was used as control (male:female; 10:12, age 42-76 years). The CT scans of the two groups were mixed and randomized. Two blinded radiologists independently reviewed the kidneys for the presence of wedge-shaped RCLs. Fisher's exact test was used to determine statistical significance. Consensus review of all imaging of positive patients with AIP and RCLs and three additional patients identified anecdotally was performed. RESULTS: Both readers independently identified the same 6/17 (35%) patients in the study group and 0/22 in the control group with two or more RCLs. This difference was statistically significant (p=0.004). The sensitivity, specificity, positive and negative predictive values of RCLs in the differentiation of AIP from pancreatic adenocarcinoma were 35%, 100%, 100%, and 67%, respectively. To the six AIP patients with RCLs, we added three more identified anecdotally. In 7/9, >5 RCLs were seen which were wedge-shaped and cortical-based, ranging from <1 to 4cm. Typical pancreatic findings of AIP were noted in all, with the gland affected focally in 5/9 patients. CONCLUSION: We have shown the presence of multiple renal cortical lesions which occur in approximately 35% of our AIP patient population.