Automated registration of brain images using edge and surface features

We present an automated multimodality (CT & MRI) registration algorithm based on hierarchical feature extraction. Two kinds of shape representations-edge and surface-are extracted hierarchically from different image modalities. The registration then is performed using least-squares matching of the user-specified (but automatically extracted) corresponding features. In our implementation, the 3-D version of the Canny edge detector is employed in the extraction of corresponding edge information. An automatic segmentation algorithm is introduced to extract the corresponding surfaces from the edges efficiently. The geometric matching of those extracted shape features then is performed using the iterative closest-point matching method.