ADVANCES IN THE TECHNIQUE OF MAMMOGRAPHY - BIMETAL ANODE MATERIAL ANDSELECTIVE FILTERING TECHNIQUE

The use of molybdenum (Mo) as material for anodes and filters in mammo graphy has been a result of contrast optimisation for breasts of low t o medium radiation absorption. To penetrate denser breasts the kV must be increased, thus increasing the fraction of the harder radiation co mponent and deteriorating image contrast. Besides this an increased ra diation exposure to the patient must be accepted. In these cases the f lexible use of rhodium (Rh) as anode and filter material is promising. A newly developed mammographic equipment (Senographe DMR, General Ele ctric-CGR) offers these features. With selective rhodium filtering and anode material our measurements confirm a reduced radiation exposure (less than 50 %) in dense breasts with significantly improved image co ntrast compared with the conventional molybdenum technique.