Fig. 2.

Feature group structure for mass Data set M (mass lesions). The features of the mass data set consisted of mammogram features, sonogram features, and patient history features. The mammogram features comprised both BI-RADS features and radiologist-interpreted findings. The sonogram features consisted of ultrasound BI-RADS features, Stavros features, and other ultrasound mass descriptors. All image features were radiologist-extracted features. The mass data set was heterogeneous in including both mammogram and sonogram views of the breast. Both mammogram and sonogram feature sets were as well as including patient history features.