Steps Toward a Stereo-Camera-Guided Biomechanical Model for Brain Shift Compensation

Surgical navigation systems provide the surgeon with a display of preoperative and intraoperative data in the same coordinate system. However, the systems currently in use in neurosurgery are subject to inaccuracy caused by intraoperative brain movement (brain shift) since they typically assume that the intracranial structures are rigid. Experiments show brain shift of up to one centimeter, making it the dominant error in the system. We propose a system that compensates for this error. It is based on a continuum 3D biomechanical deformable brain model guided by intraoperative data. The model takes into account neuro-anatomical constraints and is able to correspondingly deform all preoperatively acquired data. The system was tested on two sets of intraoperative MR scans, and an initial validation indicated that our approach reduced the error caused by brain shift.