TLD measurements of in vivo mammographic exposures and the calculated mean glandular dose across the United States.

An analysis is presented of the exposures received by TLDs placed on the breasts of 4400 women obtaining mammograms at 170 institutions across the United States. Mean glandular dose and exposure were examined as a function of compressed breast thickness. The exposure and mean glandular dose were found to increase linearly with breast thickness. The mean glandular dose typically delivered by the institutions was well below the limit of 3.0 mGy for the 4.5-cm breast. However, some institutions tend to uniformly give higher doses. In such institutions approximately 25% of 4.5-cm-thick breasts received a mean glandular dose exceeding 3.0 mGy.