BI-RADS for sonography: Positive and negative predictive values of sonographic features

OBJECTIVE. The purpose of this study was to assess the positive predictive value (PPV) and negative predictive value (NPV) of features described in the new sonographic BI-RADS lexicon for evaluating solid masses with known histologic diagnoses. MATERIALS AND METHODS. Sonograms of 403 solid lesions were analyzed by one of three dedicated breast radiologists. Each lesion was described using features from the sonographic BI-RADS lexicon. Lesion description and biopsy results were correlated. PPV and NPV were calculated. RESULTS. Histologic results showed that 141 (35%) of 403 masses were malignant. Sonographic BI-RADS descriptors showing high predictive value for malignancy include spiculated margin (86%,19/22), irregular shape (62%,102/164), and nonparallel orientation (69%,75/109). Sonographic BI-RADS descriptors highly predictive of benign lesions include circumscribed margin (90%,160/178), parallel orientation (78%, 228/294), and oval shape (84%,200/237). For the sonographic BI-RADS features of mass margin, shape, orientation, lesion boundary, echo pattern, and posterior acoustic features, descriptors chosen were significantly (p < 0.001) different for malignant and benign masses. CONCLUSION. Descriptors from the new sonographic BI-RADS lexicon can be useful in differentiating benign from malignant solid masses.