Brain tumor resection: Intraoperative monitoring with high-field-strength MR imaging-initial results

PURPOSE: To investigate the challenges and benefits of magnetic resonance (MR) imaging during brain tumor resection. MATERIALS AND METHODS: A short-bore 1.5-T MR system equipped with echo-planar-capable gradients was used in resection of brain tumors in 30 patients. MR sequences and need for contrast material enhancement were determined on the basis of the targeted lesion. MR images were acquired before, during, and after surgery. Tissue obtained at biopsy or excised as a result of intraoperative MR findings was examined histopathologically. RESULTS: MR images of enhancing lesions proved to be the most challenging to interpret intraoperatively, and relative enhancement at the resection cavity boundary was not specific for residual tumor. The ability to detect residual tumor intraoperatively resulted in a radiologically complete resection in 24 (80%) of 30 patients. The frequency of complications was low, and no untoward effects related to the MR environment were observed. CONCLUSION: Intraoperative MR imaging provided valuable information on the completeness of resection, and resection progress was well demonstrated during surgery.