Surface Reconstruction of Bone from X-ray Images and Point Distribution Model Incorporating a Novel Method for 2D-3D Correspondence

Surface reconstruction of bone from a few X-ray images and point distribution model (PDM) is discussed. We present a robust approach combining regularized morphing and shape deformation, and show its application to surface reconstruction of proximal femur. The robustness of the presented approach relies on the development of a novel method to establish correspondence between the X-ray images and the model estimated from the PDM. The correspondence is based on an iterative non-rigid twodimensional (2D) point matching process, which iteratively uses a symmetric injective nearest-neighbor mapping operator (SIN-MO) and 2D thin-plate splines (2D-TPS) based deformation to find a fraction of best matched 2D point pairs between edge points detected from the X-ray images and projections of the points on the apparent contours extracted from the estimated model. The advantages of this novel method include robustness with respect to outliers, and automatic exclusion of cross matching, which is an important property for preservation of topology. Initial quantitative and qualitative evaluation results are given which indicate the validity of our approach.