<title>Multimodality image registration based on hierarchical shape representation</title>

Abstract

Image registration is a correlation procedure that allows either the complementary study of images obtained from different modalities, or enables the analysis of images obtained by the same modality but at different times. Applied to a variety of clinical and investigational problems, image registration can offer a major advance in diagnostic imaging. In this paper, we present an automated multi-modality registration algorithm based on hierarchical feature extraction. Two kinds of shape representations -- edges and surfaces (skin surface, inner skull surface, and outer brain surface) -- are extracted hierarchically from different image modalities. The registration is then performed using the user- specified (but automatically extracted) corresponding features. Both the robustness of the algorithm and the registration accuracy using different registration features are compared in this paper. The preliminary results show that the use of edge and surface features could succeed over a large range of geometric displacements. The results also indicate that neither the edge nor the surface feature is clearly superior in terms of registration accuracy. Using the edge feature could, however, have the advantage of eliminating the surface segmentation step which requires extra complexity, variability, and time cost. We have shown the proposed 3D registration algorithm provides a simple and fast method for automatic registration of CT and MR image modalities. Preliminary results using our registration algorithm are comparable to those obtained by other techniques.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.