Virtual Reality in Medical Imaging for Image-Guided Surgery

With medical imaging equipment one can generate images of the inside of the body. The images can be used for diagnosis, but also for planning and simulation of radio-therapy, surgery and other types of interventions, as well as for guidance and navigation while intervening according to the pre-operative plan. Several registration techniques are available to transfer the pre-operative virtual plan onto the real patient on the operating table, so that planned positions, orientations and sizes can be found back. The position and orientation of surgical tools are measured so that they can be overlaid interactively onto images, showing the tools to the surgeon in relation to the patient’s anatomy and pathology. Such guidance greatly facilitates minimally invasive surgery, it improves surgical accuracy and speed, it reduces surgical risks, and it improves the surgeon’s confidence. A further step is the integration of intra-operative imaging (e.g. with microscopy, endoscopy, ultrasound, X-ray, CT and MR) to update pre-operative images for changes which have occurred, either as a result of surgery itself, or because of flexible anatomy. For microsurgery where a very high precision is needed, it is advantageous to augment the surgeon’s dexterity with the help of telemanipulators, to minify movements, to filter any remaining microtremor, and to limit the force (or degrees of freedom) of surgical instruments. Simulation of surgery is gaining acceptance for training of surgeons in the non-destructive use of laparoscopic and endoscopic surgical tools.