Dosage evaluation in mammography.

Estimates of breast dose per view are needed for selection of mammographic techniques and verification of their proper use. However, accurate dosimetry requires standardization of both the methodology and the assumed breast composition. Because several different methods have been reported, the authors developed a simple and reproducible method using a reference "average breast" composition of 50/50% water/fat by weight. Working curves were derived for average glandular and whole-breast dose per unit of exposure in air vs. HVL and thickness. When these curves are combined with on-site measurements of exposure per view, one obtains values of dose per view for each technique. Factors were also computed to correct dosage from the reference composition to other breast compositions.