Accurate localization of the optic radiation is key to improving the surgical outcome for patients undergoing anterior temporal lobe resection for the treatment of refractory focal epilepsy. Current commercial interventional magnetic... more
Accurate localization of the optic radiation is key to improving the surgical outcome for patients undergoing anterior temporal lobe resection for the treatment of refractory focal epilepsy. Current commercial interventional magnetic resonance imaging (MRI) scanners are capable of performing anatomical and diffusion weighted imaging and are used for guidance during various neurosurgical procedures. We present an interventional imaging workflow that can accurately localize the optic radiation during surgery. The workflow is driven by a near real-time multichannel nonrigid image registration algorithm that uses both anatomical and fractional anisotropy pre- and intra-operative images. The proposed workflow is implemented on graphical processing units and we perform a warping of the pre-operatively parcellated optic radiation to the intra-operative space in under 3 min making the proposed algorithm suitable for use under the stringent time constraints of neurosurgical procedures. The method was validated using both a numerical phantom and clinical data using pre- and post-operative images from patients who had undergone surgery for treatment of refractory focal epilepsy and shows strong correlation between the observed post-operative visual field deficit and the predicted damage to the optic radiation. We also validate the algorithm using interventional MRI datasets from a small cohort of patients. This work could be of significant utility in image guided interventions and facilitate effective surgical treatments.
Current state of the art neurosurgical systems do not exploit the complementary information provided by structural and diffusion MRI when aligning pre-operative and intra-operative images. We propose a multivariate registration scheme... more
Current state of the art neurosurgical systems do not exploit the complementary information provided by structural and diffusion MRI when aligning pre-operative and intra-operative images. We propose a multivariate registration scheme where structural and fractional anisotropy data are combined in a single similarity measure. We formulate the normalised mutual information expression for the multichannel scheme and compute its analytical derivative. The method was validated using both a numerical phantom and clinical data using pre and post-operative images from patients who had undergone surgery for treatment of refractory focal epilepsy and shows correlation between visual field deficit and predicted damage to the optic radiation. This work could be of significant utility in image-guided interventions and facilitate effective surgical treatments.
