2D/3D Registration of a Preoperative Model with Endoscopic Video Using Colour-Consistency

摘要

Image-guided surgery needs an effective and efficient registration between 2D video images of the surgical scene and a preoperative model of a patient from 3D MRI or CT scans. Such an alignment process is difficult due to the lack of robustly trackable features on the operative surface as well as tissue deformation and specularity. In this paper, we propose a novel approach to perform the registration using PTAM camera tracking and colour-consistency. PTAM provides a set of video images with the corresponding camera positions. Registration of the 3D model to the video images can then be achieved by maximization of colour-consistency between all 2D pixels corresponding to a given 3D surface point. An improved algorithm for calculation of visible surface points is provided. It is hoped that PTAM camera tracking using a reduced set of points can be combined with colour-consistency to provide a robust registration. A ground truth simulation test bed has been developed for validating the proposed algorithm and empirical studies have shown that the approach is feasible, with ground truth simulation data providing a capture range of ±9mm/° with a TRE less than 2mm. Our intended application is robot-assisted laparoscopic prostatectomy.