Xerographic recording of mammograms

Abstract

In xeroradiography the X-ray intensity transmitted by an object is recorded as a charge density pattern on the surface of a semi-conducting selenium plate. The characteristics of the apparatus used are described and the reasons for the peculiar “edge contrast” pattern which the powder development method yields is explained. This edge contrast enhances the visibility of any fibrous or vascular structures within soft tissue and is thus particularly suitable for mammography. Numerous examples of xeromammograms are presented. In fatty breasts the blood vessels are very clearly outlined. Cysts are readily distinguished from malignant tumours. Xeroradiography of operation specimens is useful for confirming that the whole lesion has been removed and if stereo views are taken the vascular network in and around the tumour, brought into prominence by edge contrast, can be viewed in three dimensions.