Volumetric morphologic deformation method for intersubject image registration

An automated image processing method is proposed for anatomic standardization that can elastically map one subject's magnetic resonance image (MRI) to a standard reference MRI to enable intersubject and cross-group studies. In this method, linear transformations based on bicommissural stereotaxy are first applied to grossly align the input image to the reference image. Then, the candidate corresponding regions in the input image are identified based on the contour information from the presegmented reference image. Next, an active contour model is employed to refine the contour description of the input image. Based on the contour correspondence established in these previous steps, a nonlinear transformation is determined using the proposed weighted local reference coordinate systems to warp the input image. In this method, geometric correspondence established based on contour matching is used to control the warping and the actual image values corresponding to registered coordinates need not be similar. We tested this algorithm on various synthetic and real images for intersubject registration of MRIs.