Introduction: To evaluate the clinical feasibility and efficacy of intraoperative neurophysiological monitoring (IONM) within a 3T intraoperative magnetic resonance imaging (iMRI) system.
Methods: MRI-safe electrode was chosen by assessing the safety and image quality of different electrodes implanted in a custom liquid phantom within 3T MRI environment. 57 patients with gliomas in motor areas underwent tumor resection assisted by iMRI and IONM. MRI-safe electrodes were attached to the patient’s scalp and muscles. Adverse effects caused by IONM and image distortions of iMRI were recorded; the monitoring waveform and MRI image datasets were analyzed offline. Tumor volume and motor function were assessed preoperatively and postoperatively.
Results: Al-Ti alloy electrode was demonstrated to be MRI-safe and further used in clinical study. IONM and MRI can be performed with good quality. No adverse effects caused by IONM or MRI scanning were observed. The rates of radiological gross total resection before and after continued resection following iMRI were 63.2% and 75.4%, respectively. A statistically significant difference before and after continued resection was observed in the residual tumor volume (P=0.003) and in the extent of resection (P=0.005). 8 patients (14.0%) experienced a transient postoperative motor deficit; 2 subjects (3.5%) suffered from post-op late motor deficits at the one-month follow-up.
Conclusions: IONM can be performed with standard quality within 3T iMRI environment with MRI-safe electrodes. The combined use of high-field iMRI and IONM can increase the extent of tumor resection and decrease subsequent motor deficits.
Patient Care: We managed to perform intraoperative neurophysiological monitoring with standard quality within 3.0T high-field iMRI by selecting and using MR-compatible electrodes. The combined use of high-field iMRI and IOM helps to increase the extent of tumor resection and decrease subsequent motor deficits.
Learning Objectives: By the conclusion of this session, participants should be able to:evaluate the clinical feasibility and efficiency of intraoperative neurophysiological monitoring (IOM) within 3.0T ultra high-field intraoperative magnetic resonance imaging (iMRI) system.