A computer-aided diagnosis system for breast ultrasound based on weighted BI-RADS classes.

•A computer-aided diagnosis (CAD) system for breast ultrasound based on weighted BI-RADS classes is proposed.•The BI-RADS categories are weighted by pathological information to form three classes: benign, probably benign, and malignant.•The imbalance between benign and malignant classes is reduced and the sensitivity is increased without degrading the specificity.•The classification performance of the conventional CAD system trained only with pathological information is improved by the proposed approach.•The proposed CAD system has the advantage of providing a multiclass outcome related to radiologists’ recommendations.