A NEW METHOD OF ESTIMATING CORONARY-ARTERY DIAMETER USING DIRECTION CODES IN ANGIOGRAPHIC IMAGES

The conventional method requires a centerline of a vessel to estimate the vessel diameter. Two methods of estimating the centerline of vesse ls have been reported: One is to manually define the centerline of the vessel. This potentially contributes to inter-and intra-observer vari ability. The orientation of the centerline has an effect on the diamet er function since diameters are computed perpendicular to the centerli ne. And the other is to automatically detect the centerline of the ves sel. But this is a very complicated method. In this paper, we propose a new method of estimating vessel diameter using direction codes witho ut detecting centerline. Since this method detects the vessel boundary and direction code at the same time, it simplifies the procedure and reduces execution time in estimating the vessel diameter. Compared to a method that automatically estimates the vessel diameter using center line, a proposed method provides an improved accuracy in image with po or contrast, branching or obstructed vessels. Also, this provides a go od compression of boundary description. Our experiments demonstrate th e usefulness of the technique using direction code for quantitative an giography. Experimental results justify the validity of the proposed m ethod.