Integration of functional magnetic resonance imaging supported by magnetoencephalography in functional neuronavigation

OBJECTIVE: In this study, the intraoperative visualization of functional da ta provided by functional magnetic resonance imaging (fMRI) and magnetoence phalography (MEG) leading to functional neuronavigation is demonstrated in surgery around the motor strip. METHODS: in seven patients with lesions adjacent to the central region, fMR I was performed with a 1.5-Tesla magnetic resonance system, using axial ech o-planar imaging with a motor and a sensory task. Somatosensory and motor e voked fields were recorded with a biomagnetometer. fMRI and MEG were matche d to an anatomic three-dimensional magnetic resonance image set by a contou r fit. Then this three-dimensional image data set was transferred to the na vigation microscope and displayed in the eyepieces of the microscope during surgery. Additionally, intraoperative recording of somatosensory evoked po tentials was performed for verification of the central sulcus, RESULTS: In all cases, the projection of fMRI and MEG data into the operati ng viewing field allowed easy identification of the central region, which w as confirmed by phase reversal of somatosensory evoked potentials in each c ase. fMRI and MEG measurements yielded corresponding results in each patien t. CONCLUSION: Functional neuronavigation with integration of fMRI and MEG all ows the fast identification of eloquent brain areas. The widespread availab ility of fMRI will result in a broad availability of functional neuronaviga tion, which will, in turn, contribute to the successful surgery of lesions in eloquent brain areas with lower morbidity.