Intraoperative image fusion to ascertain adequate lead placement

Background: In order to view the position of the deep brain stimulator (DBS) lead in relation to the stereotactic target on 3-tesla magnetic resonance (3T-MR) images prior to the conclusion of the procedure, intraoperative postimplantation computed tomography (CT) images were fused with preoperative 3T-MR images. The method to do this is described and discussed in this paper. Methods: Over the last year, this method was used for 8 procedures: 6 for subthalamic nucleus and 2 for ventral-intermediate nucleus of the thalamus. The procedures were done on the CT table in a stereotactic frame. CT and MR images plus coordinates from the Schaltenbrand atlas were used to plan the target. After the lead had been placed at the target, intraoperative CT images were obtained and fused with preoperative 3T-MR images prior to the conclusion of the procedure. If error was detected in the lead position, it was corrected. Results: Errors in the x-coordinate were detected in 2 patients. These errors were corrected prior to the conclusion of the procedures. Conclusion: This is a simple method to intraoperatively visualize DBS lead position on high-quality 3T-MR images. It gives the surgeon the capability to detect errors and correct them prior to the conclusion of the procedure.