Film-screen mammography: comparison of views.

The authors performed oblique, mediolateral, and cephalocaudal film-screen mammographic views for all 9,662 patients examined at the UCLA Medical Center from January 1, 1980 to December 31, 1985. In these patients, biopsies yielded 172 cancers; 87 were nonpalpable. There was a mammographic mass in 113, only calcifications in 38, and distortion or asymmetry of breast parenchyma in 12. We retrospectively determined how each view contributed to depiction of tumors: 125 cancers were seen on all views, 10 on none, 11 on the oblique only, 4 on the mediolateral only, and 3 on the cephalocaudal only. The remaining cancers were detected on various combinations of views. Cancers were missed in individual views because of overlying dense tissue or because the tumor was outside the area depicted in the film. Breast cancer screening is performed with two views of each breast. Oblique-cephalocaudal two-view mammograms showed 158 cancers; mediolateral-cephalocaudal two-view mammograms showed 151 cancers.