Depth-buffer targeting for spatially accurate 3-D visualization of medicalimages

During interactive image-guided surgery (IIGS), a surgeon uses data from me dical images to help guide the surgical procedure. At Vanderbilt University , an IIGS software system called Orion has been developed which is capable of displaying up to four 512 x 512 images and the current surgical position using an active optical tracking system, Orion is capable of displaying da ta from any tomographic image volume and from any NTSC video image. An addi tional display module has been implemented to display three-dimensional inf ormation as well as the tomographic slices, This provides the surgeon with valuable anatomical information that is not readily obtained from the tomog raphic slices alone. Before the surgery, a set of rendered images is create d, each with a different angular view of the tomographic volume in order to surround the site of surgical interest. The major objectives of the displa y module are to display the appropriate rendered image from the set, identi fy the current probe position on the selected image, and provide an indicat ion of distance between the probe and the physical point of the anatomy ind icated on the image, This can provide the surgeon with vital information su ch as distance to blood vessels, tumors, or other critical structures.