2D-3D registration of human ankle using X-ray and CT images

In this paper, we introduce a new framework for registering pre-operative 3D volumetric data to intra-operative 2D images. We are particularly interested in examining the problem of aligning CT volumes to corresponding X-ray images. Our objective is to apply the 2D-3D registration in the field of orthopedics, specifically on ankle surgery. The long-term goal of this work is to apply this technique to ankle fusion surgery to determine the proper size and orientation of the screws which are used for fusing the bones together. In addition, we try to localize the best bone region to fix these screws. Our framework adopts the shear-warp factorization method to generate synthetic 2D images from the given 3D volume. Also, the alignment score is determined according to Exponential Correlation (EC) as a new similarity measure. We used a variety of methods to evaluate registration quality of our system. It has been tested on 15 clinical CT datasets. Evaluation results indicate the degree of accuracy of our registration framework.