BREAST-CANCER CALCIFICATION MEASUREMENTS USING DIRECT X-RAY-DETECTIONIN A MONOLITHIC SILICON PIXEL DETECTOR

A prototype monolithic silicon pixel detector, developed for high-prec ision tracking at the Superconducting Super Collider, has been used to measure, by direct detection of x-rays, aluminum oxide grains from an accreditation phantom, and calcifications from a tissue sample includ ing a calcification with a width of 100 mu m (about half the diameter of the smallest ones normally seen in clinical practice). A computer m odel indicates that a future sensor, using the same basic structure bu t optimized for mammography, has the potential of improving upon the a bilities of scintillator-film and scintillator-CCD systems by observin g individual x-rays, thus allowing the possibility of combining high r esolution digital information from more than one viewing angle or x-ra y energy.