Introduction: Preoperatively acquired diffusion tensor image (DTI) and blood oxygen level dependent (BOLD) have been proved to be effective in providing more anatomical and functional information; however, the brain deformation induced by brain shift and tumor resection severely impair the correspondence between image space and patient space in image-guided neurosurgery.
Methods: To address the deformation, we developed a hybrid non-rigid registration method to register high-field preoperative MRI with low-field intra-operative MRI in order to recover the deformation induced by brain shift and tumor resection. The registered DTI and BOLD are fused with intra-operative MRI in a commercial workstation in order to allow surgeons to visually learn the locations and relationships of the brain structures, of tumor and residual tumor, and of white matter fiber tracts and functional cortex after brain deformation.
Results: The proposed hybrid registration method was evaluated by comparing the landmarks predicted by the hybrid registration method with the landmarks measured by intra-operative MRI for 10 patients. The prediction error of the hybrid method was 1.98 ± 0.63 mm, and the compensation accuracy was 73.3 ± 5.0%. Compared to the landmarks far from the resection region, those near the resection region demonstrated a significantly higher compensation accuracy (P-value = .003) although these landmarks had larger initial displacements.
Conclusions: The hybrid registration method is able to compensate for the deformation induced by brain shift and tumor resection and bring preoperatively acquired BOLD and DTI into Operating Room to augment intra-operative MRI with rich anatomical and functional information.
Patient Care: This hybrid non-rigid registration method provide more information for surgeons and improve tumor resection rate and reduce morbidity.
Learning Objectives: By the conclusion of this session, participants should be able to identify an effective method to compensate for the deformation induced by brain shift and tumor resection.