MRI-guided endoscopy in the brain: a feasability study

For neuronavigation in neuroendoscopy conventional navigation systems cannot exclude tissue movements caused by loss of cerebrospinal fluid (CSF). Open MRI can serve as a real-time navigation system if special conditions of endoscopic instruments and equipment are followed. We adapted an endoscopic system to the MRI and installed a miniaturized laser guidance system to project the central transaxial and coronal planes onto the phantom. A human cadaveric model was examined with a flexible microendoscope marked with a titanium wire inside the open magnet. The procedures were guided by gradient echo sequences refreshing the image every 4.5 seconds to control position of the endoscope. Endoscopic and corresponding MRI-findings are presented. Results and technical conditions are discussed.