Mammography is the most effective method for early detection of breast cancer and yet, 10% to 30% of women who have breast cancer and undergo mammography have negative mammograms. Furthermore, of the women who are sent to biopsy, only 20% to 40% actually have breast cancer, Quantitative analysis of the radiographic features of microcalcifications and masses may help radiologists improve their specificity. Copyright (C) 1997 by W.B. Saunders Company.