Abstract
This study was aimed at analyzing the breast compositions of 807 patients included in the database of digital mammography, and to clarify the relationship between compositional differences and the mean glandular dose (MGD).
Mammographic images of the breast composition of 807 patients, obtained us-ing 5 models of equipment at 4 facilities, were evaluated at four points according to established mam-mography guidelines. The images revealed four types of breast composition, which were divided into further groups: high-density breasts and non-high-density breasts. Furthermore, the effects of differ-ences in the breast composition on the MGD were analyzed.
The study revealed that 9.5% of the 807 breasts were almost entirely fatty, 43% had scattered areas of fibroglandular densities, 40% were heterogeneously dense, and 7.5% were extremely dense, and that with increasing age of the women, the proportion of almost entirely fatty breasts, as well as of breasts with scattered areas of fibroglandular densities increased, whereas that of the heterogeneously dense breasts and extremely dense breasts decreased. It was also found that the MGD became approxi-mately 16% to 20% higher in high-density breasts than in non-highdensity breasts.
The results of breast composition analysis showed the same trend as those reported previ-ously in Japan. However, it was revealed that high-density breasts have a higher MGD than the nonhigh-density breasts.
