Intraoperative imaging with open magnetic resonance imaging and neuronavigation

The Erlangen-concept of image-guided-surgery is based on the installation o f an open magnetic resonance (MR) scanner (Magnetom Open, 0.2 T, Siemens AG ) in a twin operating room in combination with two neuronavigation systems (Stealth NeuroStation, Sofamor Danek, MKM Zeiss). Since March 1996 this met hod has been used for a total of 402 patients, among them 44 children. In 2 14 patients, mainly with gliomas or pituitary adenomas or who needed surger y for epilepsy, we performed intraoperative MR imaging to monitor the exten t of resection, allowing a second look for possible tumor remnants and also compensating for brain shift by an intraoperative update of neuronavigatio n. Functional neuronavigation, i.e. the combination of anatomical neuronavi gation with functional imaging [e.g. magnetoencephalography (MEG) and funct ional magnetic resonance imaging (fMRI)] was used in patients with lesions in brain areas such as the motor and speech areas. For MEG we used a MAGNES II biomagnetometer (Biomagnetic Technologies, San Diego, Calif.) and for f MRI a 1.5 T Siemens Symphony MR scanner. So far we have treated 89 patients with functional neuronavigation. Our preliminary experience indicates that intraoperative MR imaging, especially in combination with functional neuro navigation, allows more radical resections with lower morbidity.