Tissue retraction for model-updated image-guided neurosurgery

With the adoption of neuronavigation techniques to aid in surgery, preoperative image-guidance has been used for the precise application of surgical instruments in the OR. However, the effect of intraoperative tissue motion on image registration has been recently quantified and shown to be significant. Given the wealth of preoperative imaging information and the availability of sparse inexpensive intraoperative data, the authors believe computational models can play a significant role in updating high resolution image databases during surgery. In order for model-updating to become a practical reality, the model must be able to account for hydrodynamic changes, gravity-induced shift, retraction and excision. In this paper, the authors illustrate a strategy for the retraction of tissue.