Although objective assessment of perioperative imaging provides a rigorous evaluation method of neurosurgical techniques in epilepsy, its use remains far from mainstream. Open surgery remains the gold standard for treatment of mesial temporal lobe epilepsy (MTLE); however, stereotactic laser ablation is a promising minimally invasive alternative. Nevertheless, the variables that may affect seizure outcome in stereotactic laser amygdalohippocampectomy (SLAH) remain unclear. While an objective endpoint such as ablated mesial temporal volumes may be significant, a standard methodology for calculating such volumes has yet to be proposed.


To formulate and test a methodology, which can aid in critical evaluation of laser trajectories, and ablation cavities in seizure patients.


We performed a retrospective study involving 16 patients undergoing SLAH our institution’s approved IRB protocol. Preoperative MRIs were processed and segmented. Postoperative MRIs were co-registered to preoperative MRIs. Laser trajectories and ablation cavities were segmented from this co-registered image. Segmented trajectories, and cavities were superimposed upon the initial MRI. The percentage of each structure affected was calculated, using a voxel by voxel comparison.


We were successfully able to determine ablation volumes and critically evaluate laser placement.


This semi-automated methodology showcases a systematic workflow that objectively evaluates perioperative imaging in neurosurgical patients.

Pages: 16-25