The role of blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) combined with diffusion tensor imaging (DTI) in surgery for tumors involving motor pathways

Blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) in combination with diffusion tensor imaging (DTI) can clearly show the specific relationship between brain tumors and motor pathways. The purpose of this study was to investigate the role of this combination in surgery for brain tumors involving motor pathways.

From September 2018 to March 2019, preoperative BOLD-fMRI and DTI examinations were performed in patients with brain tumors involving motor pathways who were being treated in a neurosurgery department. The patients were divided into two groups according to the combined examination results. In one group, the motor pathways were intact; in the other, motor pathways were infiltrated by tumors. The surgical plan was total resection of the tumor as far as possible and with no damage to the motor pathway. The preoperative and postoperative motor dysfunction and the rate of total resection in the two groups were compared.

Of the 20 patients with intact motor pathways, 15 had normal preoperative motor function, and 5 had preoperative motor dysfunction; of those 5 patients, 3 exhibited postoperative aggravation of motor dysfunction. Total excision was performed in 16 patients with intact motor pathways and incomplete excision in 4. Of the 22 patients with motor pathway infiltration, 8 had normal preoperative motor function and 14 had preoperative motor dysfunction; of those 14, 10 exhibited a postoperative increase in motor dysfunction. Total excision was performed in 8 patients with infiltrated motor pathways and incomplete excision in 14. Statistical analysis showed that there were significant differences between the two groups in preoperative motor function, postoperative changes in motor function, and total surgical resection rate (all p < 0.05).

First, whether tumors invade the motor pathway is an important factor affecting the degree of preoperative motor dysfunction. Second, the risk for postoperative motor dysfunction was lower in patients with intact motor pathways than in patients with infiltrated motor pathways. Third, the rate of total tumor resection was higher in patients with intact motor pathways than in patients with infiltrated motor pathways. Last, the combination of BOLD-fMRI and DTI aided in the decision to perform total resection.