An angiography system for angiographic examination of a patient is provided. The system has an x-ray emitter and an x-ray image detector attached to the ends of a C-arm, a patient support couch, a system control unit, an image system and a monitor. The system control unit generates a mask image that detects a reference image, effects a registration of the reference image to the C-arm, whereby if necessary a segmentation of the examination object is implemented in the reference image, contrasts image regions lying inside of the segmentation in order to generate a mask image, and subtracts the mask image from fluoroscopy live images acquired by the angiography system without contrast agent in order to form a roadmap image. The image system effects a reproduction of the roadmap images on the monitor.
