Standardized evaluation of 2D-3D registration

In the past few years a number of 2D-3D registration algorithms have been introduced. However, these methods have not been directly compared or only work for specific applications. Understanding and evaluating their performance is therefore an open and important issue. To address this challenge we introduce a standard evaluation method, which can be used for all types of methods and different applications. Our method uses the geometry of the 3D Rotational Xray (3DRX) imaging system in combination with 3D-3D registration for attaining a highly accurate ground truth for 2D multiple X-ray to 3D MR/CT/3DRX registration. The data and ground truth transformations will be made available on the Internet. Furthermore, we propose starting positions and failure criteria to allow future researchers to directly compare their methods. As an illustration, the proposed method has been used to evaluate the performance of two 2D-3D registration techniques, viz. a gradient-based and an intensity-based method, in spinal applications.