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

Abstract

Abstract.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.

Medical robotics and computer-integrated interventional medicine

“…A few recent examples from the CISST ERC include the use of intraoperative ultrasound elastography to monitor RF ablation of tumors 51 , intraoperative x-rays coregistered to trans-rectal ultrasound for assessment of prostate brachytherapy seed placement e.g., 88,89 , and the use of 2D and 3D intraoperative x-rays to assess orthopaedic procedures. Figure 7(Left) shows reconstruction of injected cement in femoroplasty from four intraoperative x-ray using a novel deformable level-set method 86 , comparing the result with a ground truth obtained from segmented CT of the femur and the results from simple intersection of segmented 2D images. Figure 7(Right) shows the use of registration of uncalibrated postoperative x-rays to a prior 3D model to assess tunnel position in anterior cruciate ligament (ACL) repair surgery.…”