DURING the past few years, there has been improvement of mammographic technology, enabling reduction of radiation dose, enhancement of image quality, and increased detection of breast cancers at an early curable stage. These advances are the result of two new imaging systems: (1) reduced-dose xeromammography, an electrostatic process using highly filtered x-rays to record on special paper an image composed of blue toner particles (Fig 1 and 2), and (2) screen-film combinations specifically designed for mammography.
Formerly, all mammographic examinations were performed with nonscreen film, and skin exposure doses of 7 to 15 rads per exposure were necessary. Now, skin doses are reduced to 0.5 to 0.9 rads per exposure. The relationship between skin exposure dose and absorbed breast tissue dose was difficult to assess, but now it can be accurately measured by refined dosimetric techniques. For a typical two-view examination, the midbreast tissue dose is 0.08 to