Surgically appropriate MIPs of tomographic angiograms

In Interactive Image Guided Surgery (IIGS), the current surgical position is indicated on sets of tomographic image volumes. To accurately visualize and localize vascular structures, modalities such as magnetic resonance angiography (MRA) and computed tomography angiography (CTA) are used in IIGS. Maximum Intensity Projection (MIP) is a post-processing technique used to visualize these vascular structures. In this method, projection rays are cast through the image and the maximum intensity is preserved. Conventional MIPs are taken from one side and cast across the volume. For more surgically appropriate images, the rays originate from a boundary plane whose location is based on the center of mass. This plane is used to help remove unnecessary and confusing information from the side opposite to the viewpoint. Individual rays are constrained within a slice, limiting the surgeon to one set of viewpoints level to the slice plane. It would be beneficial to find viewpoints that could simulate the many trajectories that might be used during a procedure. This study examines the feasibility of creating MIPs with rays extending through slices, allowing for almost any viewpoint conceivable and better planning before surgery. Special sets of MIPS can also be generated for navigation during Interactive Image Guided Surgery