| Medicine is rapidly adopting new minimally invasive techniques, especially in the realm of vascular procedures. These new techniques require spatially complex operations while providing little or no hand-eye coordination. Image-based tracking, registration, and visualization may make it easier to understand and perform these procedures, possibly shortening procedures, improving outcomes, and allowing new, more complex techniques to be pursued. This dissertation will explore the calibration, tracking, and registration issues that need to be understood to develop a viable intraoperative guidance system.; To develop an understanding of the likely benefits of a complete system for intraoperative tracking and visualization, this dissertation will consider the methods, accuracy and effectiveness of several major components in such a system. The first part of this work presents a novel phantom for simultaneous calibration of two fluoroscopes, a set of methods for accurate calibration of such systems based on bundle adjustment, and the integration of high-order distortion correction and calibration into a single optimization method. Existing methods generally address single-view calibration and distortion correction as separate steps, with the best fluoroscopic methods producing mean errors of at least 1--2mm. The methods presented herein yield a mean reconstruction error of 0.44 mm from a single calibration process. The second part describes a real-time anatomical feature tracker based on maximum-likelihood feature selection. This method is then used to determine the motion of the liver in fluoroscopic image sets from real patients. The final innovation of this dissertation is a method for registering a 3D vascular model to two calibrated angiographic views simultaneously.; Overall, this work advances our understanding of the ways in which real-time fluoroscopy can be used to precisely track and model interventional procedures interactively. These results enable sub-millimeter reconstruction of anatomical features, instruments, or other features of interest in a practical and robust manner. |
