Technical and dosimetric aspects of quality control in mammography

Mammography is an effective method for early detection of breast cancer. Before screening programmes using mammography are implemented, a risk (financial cost)/benefit analysis has to be made and a quality-control programme for the technical and dosimetric aspects has to be adopted. This should include daily checks on the film processing and the total mammography procedure. The installation of a mAs meter is essential for daily checks and can be used for determination of the absorbed dose. Accurate determination of the tube voltage is essential with regard to absorbed dose variations. The focal spot size should be measured rather than relying on the value specified by the manufacturer. The determination of the focal charge (mAs) value for actual radiographs of female breasts combined with a measurement of the compressed breast thickness provides information on the absorbed dose values for actual radiographs. An approximately 50 mm thick poly(methyl methacrylate) phantom can be used for determination of absorbed dose in mammography. (author)