A diagnostic matrix of morphologies and distributions of calcifications enables their standardized classification into BI-RADS categories. 285/328/208/29 groups of calcifications were prospectively classified as BI-RADS 4A/4B/4C/5 correlating with a risk for malignancy of 16%/27%/55%/90%. Overall, 275/849 (32%) groups of calcifications were found to be malignant.