Preoperative blood oxygen level-dependent functional magnetic resonance imaging in patients with gliomas involving the motor cortical areas

Background Blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) plays an important role in identifying functional cortical areas of the brain, especially in patients with gliomas. This study aimed to assess the value of fMRI in presurgical planning and functional outcome of patients with gliomas in the motor cortical areas. Methods Twenty-six patients with gliomas in the motor cortex were recruited in the study. Before operation, fMRI was performed in each patient to obtain the mapping of bilateral hands area on the primary sensorimotor cortex. This examination was performed on a 3.0T scanner with a bilateral hands movement paradigm. During microsurgery under awake anesthesia, the motor area was identified using direct electrical stimulation and compared with preoperative mapping. Finally the tumor was resected as much as possible with the motor cortex preserved in each patient. Karnofsky performance status (KPS) was evaluated in all patients before and after operation. Results Twenty-three patients showed a successful fMRI mapping. Among them, 19 were calssified to be grade III; 4, grade II; 3, grade I. The operation time was about 7 hours in the 23 patients, 8.5 hours in the other 3. The pre- and postoperative KPS score was 82.3 +/- 8.6 and 94.2 +/- 8.1, respectively. Conclusions Preoperative fMRI of the hand motor area shows a high consistency with intraoperative cortical electronic stimulation. Combined use of the two methods shows a maximum benefit in surgical treatment.