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

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Small solid renal masses (SRMs) are common, with up to 20% being benign.
• Accurate characterization of SRMs is crucial for appropriate management.
• Clear cell renal cell carcinoma (ccRCC) is the most frequent and potentially aggressive subtype.

Purpose of the Study:

• To introduce and explain the clear cell likelihood score (ccLS) system for MRI evaluation of SRMs.
• To standardize the assessment of ccRCC likelihood using specific imaging features.
• To guide radiologists in differentiating ccRCC from other renal masses and informing biopsy decisions.

Main Methods:

• Utilizing major MRI features (T2 signal, enhancement patterns, fat presence) and ancillary features (enhancement inversion, ratios, diffusion restriction).
• Applying the ccLS system, a Likert scale (1-5) for ccRCC likelihood.
• Illustrating the algorithm's application with case examples and discussing practical considerations.

Main Results:

• The ccLS system provides a standardized framework for categorizing SRMs based on MRI features.
• It helps assess the likelihood of ccRCC, aiding in differential diagnosis.
• The system aims to stratify patients for potential biopsy, optimizing diagnostic pathways.

Conclusions:

• The ccLS system enhances radiologists' ability to confidently identify ccRCC on MRI.
• Standardized evaluation improves management decisions and shared decision-making with patients.
• Further development and application of the ccLS system are expected to refine SRM characterization.