Intraoperative assessment of aneurysm clipping using magnetic resonance angiography and diffusion-weighted imaging: technical case report

OBJECTIVE AND IMPORTANCE: To use intraoperative magnetic resonance imaging, including magnetic resonance angiography and diffusion-weighted imaging, to monitor the surgical treatment of a patient with an intracranial aneurysm. TECHNIQUE: Intraoperative imaging was performed with a ceiling-mounted, mobile, 1.5-T magnet (developed in collaboration with Innovative Magnetic Resonance Imaging Systems, Inc., Winnipeg, MB, Canada) that included high-performance 20-mT/m gradients. Pre- and postclipping, intraoperative, T1-weighted, angiographic and diffusion-weighted magnetic resonance images were obtained from a patient with an incidental, 8-mm, anterior communicating artery aneurysm. RESULTS: T1-weighted images demonstrated brain anatomic features, with visible shifts induced by surgery. Magnetic resonance angiography demonstrated the aneurysm and indicated that, after clipping, the A1 and A2 anterior cerebral artery branches were patent. Diffusion-weighted studies demonstrated no evidence of brain ischemia. CONCLUSION: For the first time, intraoperative magnetic resonance imaging has been used to monitor the surgical treatment of a patient with an intracranial aneurysm.