Reconstruction of rotary DSA vessel axis based on the matching of multiple projections

A novel method of the matching and reconstruction of DSA vessel axis is proposed based on the redundant information from multiple two-dimensional (2-D) projections of the object. First, a correlation scheme on pixels gray level is used to extract the vessel structure on every projection. Through this way, we acquire a binary image. Secondly, Hit-Miss Transform (HMT) is applied on the binary image to produce a vessel axis image. Thirdly, an arbitrary projection is chosen as base image, and others are chosen as reference images. For each key point in the base image, the matching points are found from the key points of the reference images according to epipolar geometry and the topological linking relations of vessel branches. The matching segments are determined from matched key points. If one segment of vessel axis in the base image is confirmed to be matching with one in the reference image, an interpolation process may be used to find out the corresponding relationship of points on these two segments. Then we can get a continuous 3-D segment of DSA vessel axis according to reconstruction the matched points between two views. The whole process is executed repeatedly when another image is selected as base image. The experiment result shows that this method may provide satisfactory reconstruction even the vessel extraction result is not very accurate.