Three-dimensional/two-dimensional registration and reconstruction in image-guided surgery

Percutaneous surgical guidance by 2D fluoroscopic images is impeded by the incomplete information available from projected views. 3D image guided surgery can provide better comprehension of 3D anatomy and present objects not apparent by fluoroscopy. However, current solutions for 3D surgical guidance typically rely on a small number of external markers or landmarks. This is convenient but can lead to navigational errors at the target site. This dissertation explores the feasibility of using the digital images of anatomical structures as navigational references for surgical guidance. A register-and-reconstruct paradigm is proposed. Fluoroscopic images are registered with preoperative patient CT. Given registered bi-plane images, the instrument pose can be reconstructed.; My 3D/2D registration algorithm uses the medial curves of tubular structures and has the advantage of mathematical and implementation simplicity. Theoretical analysis and experiments show this algorithm to be robust and accurate. A method for synthesizing tubular structures extends the algorithm, permitting arbitrary anatomical structures to be used. The synthesis is a novel application of the parallax effect on digitally reconstructed radiographs. A separate algorithm was developed for stereotactic instrument pose recovery from projection images. The method is based on the geometric properties of bi-plane imaging. An error model was developed to analyze performance characteristics. Both theoretical analysis and experiments using the Visible Human dataset and skull phantoms indicate that the register-and-reconstruct paradigm is accurate to at least 1.5mm, well within the requirements of the driving problem of percutaneous rhizotomy.