Ultrasound positive predictive values by BI-RADS categories 3-5 for solid masses: An independent reader study.

Objective: We assessed multiple readers' positive predictive values (PPVs) for ACR BI-RADS 3, 4a, 4b, 4c and 5 masses on ultrasound (US) pre- and post-proposed guidelines.

Methods: This retrospective, IRB-approved study included four American and four non-American readers who assigned BI-RADS categories for US images of 374 biopsy-proved masses. Readers were offered guidelines and re-classified the masses.