Multiresolution Search Strategy for Elastic Registration of X-Ray Angiography Images

Digital subtraction angiography (DSA) is now a widely used X-ray technique for vascular imaging. However, due to unavoidable motions, the subtraction images often suffer from misregistration artifacts. To cope with this problem and improve the diagnostic value of DSA, registration algorithms are often employed before subtraction. In this paper, a novel elastic registration algorithm for registration of the angiographic images is presented. This algorithm is built upon a multiresolution search strategy in which the global transformation is calculated iteratively based on local search in coarse and fine sub-image blocks, and local searches are accomplished in a differential multiscale framework. Experimental results with several clinical data sets show that this approach is highly effective.