Real-time three-dimensional (3D) visualization of fusion image for accurate subdural electrodes placement of epilepsy surgery.

INTRODUCTION: The perfect match between pre-surgical estimated seizure onset zone and subdural electrodes (SEs) position is requested for epilepsy surgery. However, post-surgical neuro images sometimes disappoint physicians due to SEs malposition. To place SEs, we used to use intraoperative photograph and fluoroscopy. With this procedure, we just recognized approximate location of SEs during surgery. The purpose of the study is to perform precise SEs location intraoperatively using intra operative computer tomography (CT) and image-guidance.

PATIENTS AND METHODS: There were 12 patients with intractable epilepsy. The age ranged from 5years old to 42years old. They underwent SEs placement. The patients intraoperatively underwent brain CT. Their CT images were automatically fused onto their 3D magnetic resonance image (MRI) brain image at the monitor of the image-guidance. In case of malposition or under coverage, neurosurgeons revised or add SEs along with advice of epileptologists and neurophysiologists.

RESULT: Patients underwent intraoperative CT scans once to three times. Epileptologists, neurophysiologists and surgeons could intraoperatively recognize the relationship between the SEs and the 3D MRI brain surface. We could intraoperatively discuss the localization of SEs and correct the position or add more SEs to cover estimated seizure onset zone along with real-time visualized image. We could avoid postoperative malposition of the SEs, so there were no another SEs operation for revision.

CONCLUSION: The intraoperative real-time visualization of SEs on 3D brain surface image helped us to perform accurate electrodes placement and could avoid the electrode malposition.