Breast Imaging-Reporting and Data System Assessment Category 4B

**Semantic type:** Classification

**Definition:** An assessment subcategory of the American College of Radiology Breast Imaging-Reporting and Data System (BI-RADS) that indicates that the findings of a breast imaging study are moderately suspicious for malignancy, with a 10-50% probability of malignancy.

**Synonyms:** - BI-RADS 4B