Renal Mass Imaging with MRI Clear Cell Likelihood Score: A User's Guide.

Small solid renal masses (SRMs) are frequently detected at imaging. Nearly 20% are benign, making careful evaluation with MRI an important consideration before deciding on management. Clear cell renal cell carcinoma (ccRCC) is the most common renal cell carcinoma subtype with potentially aggressive behavior. Thus, confident identification of ccRCC imaging features is a critical task for the radiologist. Imaging features distinguishing ccRCC from other benign and malignant renal masses are based on major features (T2 signal intensity, corticomedullary phase enhancement, and the presence of microscopic fat) and ancillary features (segmental enhancement inversion, arterial-to-delayed enhancement ratio, and diffusion restriction). The clear cell likelihood score (ccLS) system was recently devised to provide a standardized framework for categorizing SRMs, offering a Likert score of the likelihood of ccRCC ranging from 1 (very unlikely) to 5 (very likely). Alternative diagnoses based on imaging appearance are also suggested by the algorithm. Furthermore, the ccLS system aims to stratify which patients may or may not benefit from biopsy. The authors use case examples to guide the reader through the evaluation of major and ancillary MRI features of the ccLS algorithm for assigning a likelihood score to an SRM. The authors also discuss patient selection, imaging parameters, pitfalls, and areas for future development. The goal is for radiologists to be better equipped to guide management and improve shared decision making between the patient and treating physician. © RSNA, 2023 Quiz questions for this article are available in the supplemental material. See the invited commentary by Pedrosa in this issue.

Second-opinion interpretation of outside facility general ultrasound studies: rate of discrepancies and management change.

BACKGROUND: Second-opinion reads on imaging studies are common for CT and MRI, but many institutions are hesitant to implement a workflow for second read of ultrasound studies performed at other facilities due to quality considerations. OBJECTIVE: The purpose of this study was to assess discrepancy rates between initial and second-opinion general ultrasound reports METHODS: We reviewed all requests of second-opinion US studies referred to our tertiary care center between 02/01/2020 and 06/23/2022. We evaluated percentage of exams that were interpreted versus archived. Whenever the original report was available (n = 196 studies), we evaluated any discrepancy in findings, interpretation, and potential management change based on second report compared to the initial report as evaluated by consensus agreement of 3 subspecialized radiologists. RESULTS: A total of 586 ultrasound studies for 533 patients were nominated for consult. After excluding 58 studies for technical reasons (e.g., duplicate nomination, images for procedure guidance, modality is not ultrasound) and 282 studies that were archived by the reading radiologist due to various objective (e.g., studies such as echocardiography not interpreted by the abdominal imagers or more recent study available obviating need for consultation) and subjective (e.g., suboptimal image quality, lack of cine clips) reasons, a total of 246 studies were reinterpreted and were further analyzed. Only 21/246 patients (8.5%) got repeat ultrasound of the same body part within 3 months of original study date. The original (first-read) report was available for 196/246 studies, with discrepancy present between the first and second reads in 74/196 (37.8%) studies, with potential management change in 51/196 (26.0%) studies. CONCLUSION: Second-opinion interpretation of outside ultrasound examinations by subspecialized radiologists can result in recommended management change in 26% of studies indicating potential for added value to reinterpreting ultrasound studies despite the concerns for quality control.