Multimodal Navigation in Glioma Surgery

Neuronavigation has become a useful tool in neurosurgical operating-theatres, displaying tumor outlines in the navigation-monitor (segmented preoperatively in the 3D-MRI dataset) and the operating-microscope. Furthermore, preoperatively assessed functional data can also be integrated: Functional MRI (fMRI) and magnetoencephalography (MEG) enable the visualization of eloquent cortical areas. MR-Spectroscopy (MRS), positron emission computed tomography (PET) and single-photon-emission-computed-tomography (SPECT) demonstrate metabolic data. Fiber-tractography, today mostly based on a diffusion-weighted image data set (DTI), enables us to outline subcortical major white matter tracts, for example the corticospinal tract or the speech-associated tracts. A combination of these methods is today known as multimodal imaging. Multimodal imaging contributes to maximum resection of intracerebral lesions such as malignant gliomas without an aggravation of postoperative morbidity, especially in combination with intraoperative MRI to overcome the problem of the so called “brain-shift”.