Performance evaluation of a stereoscopic based 3D surface localiser for image-guided neurosurgery

This paper reports the performance evaluation of a method for visualisation and quantification of intraoperative cortical surface deformations. This method consists in the acquisition of 3D surface meshes of the operative field directly in the neuronavigator's coordinate system by means of stereoscopic reconstructions, using two cameras attached to the microscope oculars. The locations of about 300 surfaces are compared to the locations of two reference surfaces from a physical phantom: a segmented CT scan with image-to-physical fiducial-based registration, used to compute the overall system performance, and a cloud of points acquired with the neuronavigator's optical localiser, used to compute the intrinsic error of our method. The intrinsic accuracy of our method was shown to be within 1 mm.