US of breast masses categorized as BI-RADS 3, 4, and 5: pictorial review of factors influencing clinical management.

The Breast Imaging Reporting and Data System (BI-RADS) lexicon for ultrasonography (US) is based on the established lexicon used successfully in mammography and attempts to provide a common language to avoid ambiguity in interpreting, reporting, and teaching breast US. Proper and consistent use of the BI-RADS US lexicon has numerous advantages, including facilitating (a) communication of final assessment categories that clearly indicate management recommendations, (b) data tracking for self-audits, and (c) clinical review of outcome summaries. However, the literature to date does not include sufficient data on outcomes to validate clinical use of the BI-RADS US lexicon. In this article, a pictorial review of the BI-RADS US lexicon descriptors is provided, and specific cases from a retrospective review are used to highlight the challenges in using the BI-RADS US lexicon. With these examples, suggestions are offered for greater clarity in the use of this lexicon. The technical challenges in follow-up US imaging are described. The challenges in assigning final assessment categories are detailed, as well as the clinical factors that may influence decision making and the management of certain lesions.