Digital angiographic apparatus

摘要

A digital angiographic apparatus for reducing exposure of patients to X-ray radiation, and completely eliminating a slip or deviation between mask image and live image. A radiographic image is picked up by emitting X rays through a selected site of a patient injected with a contrast medium. The radiographic image is converted to digital data to obtain a basic image. The basic image is used as a live image retaining high frequency components reflecting blood vessels and the like into which the contrast medium is injected. The basic image is subjected to appropriate frequency processing to remove high frequency components (reflecting the blood vessels and the like), thereby to obtain a mask image. A control unit subtracts the mask image from the live image to obtain a subtraction image extracting a blood vessel image.