Mammographic detectability of breast microcalcifications

Controlled in vitro studies of breast microcalcification detectability were done comparing a wide variety of standard and state-of-the-art mammography techniques (conventional and microfocal spot x-ray tubes, screen-film and xeroradiographic recording systems, contact and magnification techniques). Results confirmed previous observations that geometric unsharpness is the limiting factor in microcalcification detectability for most conventional mammography systems. Results also indicated superior microcalcification detection for: xeroradiographic over screen-film recording systems, positive-mode over negative-mode xeroradiography, microfocal spot contact over conventional contact techniques, and microfocal spot magnification over all contact techniques. No differences were found between a standard screen-film technique and a screen-film technique requiring about one-half the radiation exposure. On the other hand, although there was no differences between standard xeroradiography and a modest-added-filtration (reduced-dose) xeroradiographic technique, standard xeroradiography demonstrated superior microcalcification detection over a reduced-dose technique that used large amounts of added beam filtration. The clinical applicability of these findings is discussed.