Registration of multi-modal brain images using the rigidity constraint

A template-matching approach to registration of volumetric images is described. The process automatically selects about a dozen highly detailed and unique templates (cubic or spherical subvolumes) from the target volume and locates the templates in the reference volume. The centroids of four correspondences best satisfying the rigidity constraint are then used to determine the transformation matrix that resamples the target volume to overlay the reference volume. Different similarity measures used in template matching are discussed and experimental results are presented. The proposed registration method produces a median error of 2.8 mm when registering Venderbilt brain image data sets and an average registration time of 2.5 minutes on a 400 MHz PC.