A Multi-view Active Contour Method for Bone Cement Reconstruction from C-Arm X-Ray Images

A novel algorithm is presented to segment and reconstruct injected bone cement from a sparse set of X-Ray images acquired at arbitrary poses. The Sparse X-Ray Multi-view Active Contour (SxMAC – pronounced “smack”) can (1) reconstruct objects for which the background partially occludes the object in X-Ray images, (2) use X-Ray images acquired on a non-circular trajectory, and (3) incorporate prior CT information. The algorithm’s inputs are pre-processed X-Ray images, their associated pose information, and prior CT, if available. The algorithm initiates automated reconstruction using visual hull computation from a sparse number of x-ray images. It then improves the accuracy of the reconstruction by optimizing a geodesic active contour. A cadaver experiment demonstrates SxMAC’s ability to reconstruct high contrast bone cement that has been injected into a femur and achieve sub-millimeter accuracy with 4 images.