title: An Optimized Spline-Based Registration of a 3D CT to a Set of C-Arm Images.
abstract: We have developed an algorithm for the rigid-body registration of a CT volume to a set of C-arm images. The algorithm uses a gradient-based iterative minimization of a least-squares measure of dissimilarity between the C-arm images and projections of the CT volume. To compute projections, we use a novel method for fast integration of the volume along rays. To improve robustness and speed, we take advantage of a coarse-to-fine processing of the volume/image pyramids. To compute the projections of the volume, the gradient of the dissimilarity measure, and the multiresolution data pyramids, we use a continuous image/volume model based on cubic B-splines, which ensures a high interpolation accuracy and a gradient of the dissimilarity measure that is well defined everywhere. We show the performance of our algorithm on a human spine phantom, where the true alignment is determined using a set of fiducial markers.
authors.affiliation: Biomedical Imaging Group, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne VD CH-1015, Switzerland  ;  Institut de Minéralogie et de Physique des Milieux Condensés, Université Pierre et Marie Curie, Paris 75015, France.
authors.forename: S
authors.initials: S
authors.lastname: Jonić
authors.forename: P
authors.initials: P
authors.lastname: Thévenaz
authors.forename: G
authors.initials: G
authors.lastname: Zheng
authors.forename: L-P
authors.initials: LP
authors.lastname: Nolte
authors.forename: M
authors.initials: M
authors.lastname: Unser