Faculty Bibliography

Uterine sarcomas are a group of rare uterine tumors comprised of multiple subtypes with different histologic characteristics, prognoses, and imaging appearances. Identification of uterine sarcomas and their differentiation from benign uterine disease on imaging is of critical importance for treatment planning to guide appropriate management and optimize patient outcomes. Herein, we review the spectrum of uterine sarcomas with a focus on the classification of primary sarcoma subtypes and presenting the typical MR imaging appearances.

Current disparities in the access to diagnostic imaging for Black patients and the underrepresentation of Black physicians in radiology, relative to their representation in the general U.S. population, reflect contemporary consequences of historical anti-Black discrimination. These disparities have existed within the field of radiology and professional medical organizations since their inception. Explicit and implicit racism against Black patients and physicians was institutional policy in the early 20th century when radiology was being developed as a clinical medical field. Early radiology organizations also embraced this structural discrimination, creating strong barriers to professional Black radiologist involvement. Nevertheless, there were numerous pioneering Black radiologists who advanced scholarship, patient care, and diversity within medicine and radiology during the early 20th century. This work remains important in the present day, as race-based health care disparities persist and continue to decrease the quality of radiology-delivered patient care. There are also structural barriers within radiology affecting workforce diversity that negatively impact marginalized groups. Multiple opportunities exist today for antiracism work to improve quality of care and to apply standards of social justice and health equity to the field of radiology. An initial step is to expand education on the disparities in access to imaging and health care among Black patients. Institutional interventions include implementing community-based outreach and applying antibias methodology in artificial intelligence algorithms, while systemic interventions include identifying national race-based quality measures and ensuring imaging guidelines properly address the unique cancer risks in the Black patient population. These approaches reflect some of the strategies that may mutually serve to address health care disparities in radiology. ^© RSNA, 2023 See the invited commentary by Scott in this issue. Quiz questions for this article are available in the supplemental material.

MR imaging plays a key role in the characterization of adnexal lesions of indeterminate malignant potential found at ultrasound. Recently, the Ovarian-Adnexal Reporting and Data Systems (O-RADS) MRI lexicon and scoring system was developed to aid in standardization of reporting and interpretation of adnexal lesions, allowing for risk stratification based on MR imaging findings. This in turn can help improve communication between radiologists and referring providers, and potentially aid the selection of optimal treatment options. This article provides a detailed review of the lexicon and the scoring rubric of the O-RADS MRI risk stratification system.

Laparoscopic myomectomy, a common gynecologic operation in premenopausal women, has become heavily regulated since 2014 following the dissemination of unsuspected uterine leiomyosarcoma (LMS) throughout the pelvis of a physician treated for symptomatic leiomyoma. Research since that time suggests a higher prevalence than previously suspected of uterine LMS in resected masses presumed to represent leiomyoma, as high as one in 770 women (0.13%). Though rare, the dissemination of an aggressive malignant neoplasm due to noncontained electromechanical morcellation in laparoscopic myomectomy is a devastating outcome. Gynecologic surgeons' desire for an evidence-based, noninvasive evaluation for LMS is driven by a clear need to avoid such harms while maintaining the availability of minimally invasive surgery for symptomatic leiomyoma. Laparoscopic gynecologists could rely upon the distinction of higher-risk uterine masses preoperatively to plan oncologic surgery (ie, potential hysterectomy) for patients with elevated risk for LMS and, conversely, to safely offer women with no or minimal indicators of elevated risk the fertility-preserving laparoscopic myomectomy. MRI evaluation for LMS may potentially serve this purpose in symptomatic women with leiomyomas. This evidence review and consensus statement defines imaging and disease-related terms to allow more uniform and reliable interpretation and identifies the highest priorities for future research on LMS evaluation.

Intrauterine devices (IUDs) are one of the most common forms of long-term contraception used by patients around the world. Many studies have been performed over the past few decades demonstrating the safety of many common hormonal and metallic intrauterine devices in Magnetic Resonance (MR) imaging; however, the stainless steel ring IUD (often termed the "Chinese" IUD) is still considered MR Unsafe. This device was used in the 1980s and 1990s in China, where as many as 60 million women in China were using an IUD by 1988, and approximately 90% of those were stainless steel ring IUDs. In a major metropolitan area hospital such as ours with a large immigrant population, we encounter females with this ring IUD several times a year. As this population ages, the need for medical care (and concomitantly, MR imaging) is projected to increase. The purpose of this case review is to examine the imaging and clinical course of patients with stainless-steel ring intrauterine devices who safely received 1.5T Brain MR scans at our institution for clinically necessary diagnostic imaging.

PURPOSE/OBJECTIVE:Symptomatic peripheral vascular lesions in adults are often clinically diagnosed as benign vascular anomalies and may receive MRI/MRA for pre-treatment vascular mapping. Malignant neoplasms are difficult to distinguish from benign vascular anomalies on MRI/MRA. This study was performed to determine if there are imaging signs that can distinguish malignancies from benign vascular anomalies in adults imaged with MRI/MRA. MATERIALS AND METHODS/METHODS:A radiology database was retrospectively searched for ISSVA classification terms in MRI/MRA reports from 1/1/2002-1/1/2019. Adult patients (n = 50, 52 corresponding lesions) with contrast-enhanced MRI/MRA, peripheral soft tissue based lesion (s), and available pathology or long-term (>1 year) imaging follow-up were included. MRI/MRA images were reviewed by 3 readers for the following lesional characteristics: morphology (marginal lobulation, internal septations, distinct soft tissue mass), peri-articular location, T2-weighted characteristics (hyperintensity, heterogeneity, perilesional edema, and adjacent triangular T2-peaks), bulk fat, hemorrhage, enhancement pattern (peripheral, diffuse, or absent), neovascularity, low-flow venous malformation type enhancement, arterial enhancement within 6 s, enhancement curve (progressive, plateau, or washout), measured size, and multifocality. The MRI/MRA features' associated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. To identify factors predictive of malignancy, a two-stage multivariable analysis was performed. RESULTS:23% (12/52) of the lesions, corresponding to 22% (11/50) of the patients, were malignant neoplasms. No single imaging feature reliably predicted malignancy (PPV ≤ 60%). Absence of distinct soft tissue mass excluded malignancy (NPV 100%). Multivariate analysis derived a summary score based on the five strongest predictors of malignancy: adjacent T2 peaks, age ≥ 70 years, distinct soft tissue mass, lesion size ≥ 5 cm, and absence of septations. A score ≥ 3 resulted in sensitivity of 92% and specificity of 85%. CONCLUSION/CONCLUSIONS:Extremity MRI/MRA rarely differentiates malignant from benign soft-tissue vascular tumors in adults. However, MRI/MRA can suggest malignancy when patient age and multiple imaging features are considered. Periodic clinical follow-up after the planned endovascular or operative procedure should be performed to avoid missing a malignancy.

Background Solid small renal masses (SRMs) (≤4 cm) represent benign and malignant tumors. Among SRMs, clear cell renal cell carcinoma (ccRCC) is frequently aggressive. When compared with invasive percutaneous biopsies, the objective of the proposed clear cell likelihood score (ccLS) is to classify ccRCC noninvasively by using multiparametric MRI, but it lacks external validation. Purpose To evaluate the performance of and interobserver agreement for ccLS to diagnose ccRCC among solid SRMs. Materials and Methods This retrospective multicenter cross-sectional study included patients with consecutive solid (≥25% approximate volume enhancement) SRMs undergoing multiparametric MRI between December 2012 and December 2019 at five academic medical centers with histologic confirmation of diagnosis. Masses with macroscopic fat were excluded. After a 1.5-hour training session, two abdominal radiologists per center independently rendered a ccLS for 50 masses. The diagnostic performance for ccRCC was calculated using random-effects logistic regression modeling. The distribution of ccRCC by ccLS was tabulated. Interobserver agreement for ccLS was evaluated with the Fleiss κ statistic. Results A total of 241 patients (mean age, 60 years ± 13 [SD]; 174 men) with 250 solid SRMs were evaluated. The mean size was 25 mm ± 8 (range, 10-39 mm). Of the 250 SRMs, 119 (48%) were ccRCC. The sensitivity, specificity, and positive predictive value for the diagnosis of ccRCC when ccLS was 4 or higher were 75% (95% CI: 68, 81), 78% (72, 84), and 76% (69, 81), respectively. The negative predictive value of a ccLS of 2 or lower was 88% (95% CI: 81, 93). The percentages of ccRCC according to the ccLS were 6% (range, 0%-18%), 38% (range, 0%-100%), 32% (range, 60%-83%), 72% (range, 40%-88%), and 81% (range, 73%-100%) for ccLSs of 1-5, respectively. The mean interobserver agreement was moderate (κ = 0.58; 95% CI: 0.42, 0.75). Conclusion The clear cell likelihood score applied to multiparametric MRI had moderate interobserver agreement and differentiated clear cell renal cell carcinoma from other solid renal masses, with a negative predictive value of 88%. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Mileto and Potretzke in this issue.

Primary vaginal cancer is rare, comprising 1% to 2% of gynecologic malignancies and 20% of all malignancies involving the vagina. More frequently, the vagina is involved secondarily by direct invasion from malignancies originating in adjacent organs or by metastases from other pelvic or extrapelvic primary malignancies. Data on the use of imaging in vaginal cancer are sparse. Insights are derived from the study of imaging in cervical cancer and have reasonable generalizability to vaginal cancer due to similar tumor biology. Given the trend toward definitive chemoradiation for both cancers in all but early stage lesions, principles of postchemoradiation tumor response evaluation are largely analogous. Accordingly, many of the recommendations outlined here are informed by principles translated from the literature on cervical cancer. For pretreatment assessment of local tumor burden and in the case of recurrent vaginal cancer, MRI is the preferred imaging modality. PET/CT has demonstrated utility for the detection of nodal metastatic and unexpected distant metastatic disease. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

OBJECTIVE:This study aimed to evaluate the image quality, image artifacts, radiologist confidence, and ability to provide definitive diagnosis for all patients with magnetic resonance imaging (MRI) performed after an abdominal fluoroscopic examination and to determine the utility of MRI in this setting. METHODS:Thirty-one MRI examinations performed a median of 2 days after fluoroscopic bowel evaluation (barium, n = 13; iodine, n = 18), 20 within 3 days of MRI, were retrospectively reviewed. The image quality, artifact emanating from bowel, inhomogeneity artifact, radiologist confidence, ability to render a definitive diagnosis, and identification of emergent or important findings for all MRI examinations were assessed. These same features were evaluated on 5 computed tomographies performed after fluoroscopy (before the MRI) in the same cohort. RESULTS:All 31 MRI examinations performed after fluoroscopic studies with concentrated barium or iodine solutions were diagnostic for answering the clinical question according to radiologist and report review, regardless of magnet strength and type of fluoroscopic contrast ingested. Magnetic resonance imaging after fluoroscopy had excellent overall image quality (mean score, 4.74/5), minimal to no artifact emanating from bowel (mean, 4.63/5), minimal inhomogeneity artifact (mean, 4.38/5), and excellent diagnostic confidence (mean, 4.98/5). No additional imaging was necessary for diagnosis after MRI. Computed tomography after fluoroscopy had lower overall image quality, more image artifacts, and lower diagnostic confidence (P < 0.05). CONCLUSIONS:Magnetic resonance imaging is a useful tool for evaluating patients with retained concentrated enteric contrast from recent fluoroscopic examinations. In the absence of contraindication, MRI should be considered in the evaluation of urgent clinical problems in patients who recently underwent a fluoroscopic bowel evaluation.

Cystic renal masses are commonly encountered in clinical practice. In 2019, the Bosniak classification of cystic renal masses, originally developed for CT, underwent a major revision to incorporate MRI and is referred to as the Bosniak Classification, version 2019. The proposed changes attempt to (a) define renal masses (ie, cystic tumors with less than 25% enhancing tissue) to which the classification should be applied; (b) emphasize specificity for diagnosis of cystic renal cancers, thereby decreasing the number of benign and indolent cystic masses that are unnecessarily treated or imaged further; (c) improve interobserver agreement by defining imaging features, terms, and classes of cystic renal masses; (d) reduce variation in reported malignancy rates for each of the Bosniak classes; (e) incorporate MRI and to some extent US; and (f) be applicable to all cystic renal masses encountered in clinical practice, including those that had been considered indeterminate with the original classification. The authors instruct how, using CT, MRI, and to some extent US, the revised classification can be applied, with representative clinical examples and images. Practical tips, pitfalls to avoid, and decision tree rules are included to help radiologists and other physicians apply the Bosniak Classification, version 2019 and better manage cystic renal masses. An online resource and mobile application are also available for clinical assistance. An invited commentary by Siegel and Cohan is available online.^©RSNA, 2021.