Intraoperative MR imaging guidance for intracranial neurosurgery: Experience with the first 200 cases

PURPOSE: To review preliminary experience with an open-bore magnetic resona nce (MR) imaging system for guidance in intracranial surgical procedures. MATERIALS AND METHODS: A vertically oriented, open-configuration 0.5-T MR i mager was housed in a sterile procedure room. Receive and transmit surface coils were wrapped around the patient's head, and images were displayed on monitors mounted in the gap of the magnet and visible to surgeons. During 2 years, 200 intracranial procedures were performed. RESULTS: There were ill craniotomies, 68 biopsies, 12 intracranial cyst eva luations, four subdural drainages, and five transsphenoidal pituitary resec tions performed with the intraoperative MR unit. In each case, the intraope rative MR system yielded satisfactory results by allowing the radiologist t o guide surgeons toward lesions and to assist in treatment. In two patients , hyperacute hemorrhage was noted and removed. The duration of the procedur e and the complication rate were similar to those of conventional surgery. CONCLUSION: Intraoperative MR imaging was successfully implemented for a va riety of intracranial procedures and provided continuous visual feedback, w hich cn be helpful in all stages of neurosurgical intervention without affe cting the duration of the procedure or the incidence of: complications. Thi s system has potential advantages over conventional frame-based and framele ss stereotactic procedures with respect tb the safety and:effectiveness of neurosurgical interventions.