Survey of doses in screening mammography.

A survey was conducted over a period of several weeks to ascertain the mean glandular dose (MGD) to breast tissue arising from screening mammography. This survey found a MGD of 2.26 mGy per film for a sample of 2051 films and an average value of the MGD for each woman screened of 4.6 mGy for the 490 women included in the sample. The results revealed that there was a slight but significant trend towards lower MGD values with increasing age over 60. This study offers a method whereby from a knowledge of the X-ray tube potential, breast thickness and the recorded mAs a relatively reliable estimate of the MGD may be obtained for individual women.