THE IMPACT OF ANATOMIC VARIATIONS ON ABSORBED RADIATION-DOSES IN MAMMOGRAPHY

Variations in breast anatomy influence the radiographic performance an d have to be considered in optimisation procedures. In order to gain k nowledge on this subject the following data for 4442 women of age 40-6 9 undergoing screening with mammography were recorded: age, breast thi ckness under film compression, breast pattern according to Wolfe, expo sure data and optical film density. The individual mean absorbed dose to the glandular tissue was estimated from the measured exposure data using published conversion factors. Correlations were established betw een the above mentioned parameters. The suitability of PMMA as breast substitute material was investigated by deducing the phantom thickness that matches film density and exposure for different breast thickness es and for the mammographic techniques involved. Suggestions for the d esign of standard phantoms to be used in daily clinical practice are g iven.