Locating back position of the relatively elastically deformed three-dimensional images by corresponding surfaces

摘要

An 3D imaging method registers relatively deformed first and second volumetric images of an object which may be obtained from different imaging modalities, and/or at different times by performing an elastic geometric transformation on one of the volumetric images. The method includes extracting first and second corresponding surfaces from the respective first and second images, which surfaces delineate the same feature, such as a bone/tissue interface. This is done by extracting a stack of contours for each surface. The first surface is iteratively warped toward alignment with the second surface to arrive at a global translation vector and a set of residual surface distortion vectors. Volume distortion vectors, determined by applying a weighting function to the residual surface distortion vectors, are used to indicate the locations in the second volumetric image of voxel centers whose interpolated intensities are to be moved to lattice points. The weighting function includes a constant indicative of elastic stiffness of the second volume. The extraction of the first surface, surface warping, and volume distortion vector determination steps are repeated in successive iterations until a measure of mis-registration between the volumetric images is less than a predetermined value, with the elastic stiffness constant being decreased each time.