THE DETECTION OF BREAST MICROCALCIFICATIONS WITH MEDICAL ULTRASOUND

Microcalcifications are small crystals of calcium apatites which form in human tissue through a number of mechanisms. The size, morphology, and distribution of microcalcifications are important indicators in th e mammographic screening for and diagnosis of various carcinomas in th e breast. Although x-ray mammography is currently the only accepted me thod for detecting microcalcifications, its efficacy in this regard ca n be reduced in the presence of dense parenchyma. Current ultrasound s canners do not reliably detect microcalcifications in the size range o f clinical interest. The results of theoretical, simulation, and exper imental studies focused on the improvement of the ultrasonic visualiza tion of microcalcifications are presented. Methods for estimating the changes in microcalcification detection performance which result from changes in aperture geometry or the presence of an aberrator are prese nted. An analysis of the relative efficacy of spatial compounding and synthetic receive aperture geometries in the detection of microcalcifi cations is described. The impact of log compression of the detected im age on visualization is discussed. Registered high resolution ultrasou nd and digital spot mammography images of microcalcifications in excis ed breast carcinoma tissue and results from the imaging of suspected m icrocalcifications in vivo are presented. (C) 1997 Acoustical Society of America.