*2.9.6 Multimodal framework*

The advent of MRI has tremendously advanced the field of epilepsy surgery. Various MRI techniques providing information on function and connections of different areas of the brain have helped with surgical planning immensely. However, the clinical utility of these techniques in large patient population has not been studied. To this date, a significant number of patients with refractory partial epilepsy still do not have an identifiable lesion on MRI. In such cases results of structural MRI postprocessing need to be confirmed with modalities that can characterize the pathophysiologic features of suspicious imaging findings. Invasive intracranial monitoring is often required, despite which the outcome remains poor. In the context of presurgical evaluation, localization data acquired from seizure semiology, magnetic source imaging (MSI), EEG, MEG, PET and SPECT may help pinpoint the area of interest. Studies have shown combined features from MRI and PET outperformed MRI postprocessing by itself, PET postprocessing by itself, and multimodal visual analysis [101, 102]. Development of newer MR techniques in the future may also have the potential to improve the understanding of the cytoarchitectural and molecular abnormalities of the brain with a greater impact in the field of epilepsy. Understanding postprocessing-positive structural changes outside the assumed epileptogenic zone will require further correlative studies with electrophysiology, pathology, and long-term surgical follow-up.
