In this paper we present a algorithm for the real-time enhancement and detection of blood vessels in medical images. The algorithm is based on a set of linear lters sensitive to vessels of dierent orientation and thickness. Such lters are obtained as linear combinations of properly shifted Gaussian kernels. The output of multiple oriented vessel-enhancing lters can be integrated to obtain images in which vessels are highly enhanced independently of their direction and thickness. To avoid spurious responses in the presence of step edges or to enhance the skeletons of vessels, the output of directional lters can be validated before integration. Skeleton detection and vessel segmentation can be performed via thresholding with hysteresis. Experimental results on synthetic images and real coronary arteriograms are reported. Keywords Vessel Enhancement, Vessel Detection, Realtime Processing, Skeleton Detection, Vessel Segmentation. Address for Correspondence Riccardo Poli...