Can fMRI metrics lateralize epileptogenic hypometabolic FDG-PET regions? A simultaneous PET/MR investigation in focal epilepsy

Locally reduced glucose metabolism (i.e. hypometabolism) derived from the 18-FDG positron emission tomography (FDG-PET) is considered to be a valuable biomarker for epileptogenic zone localization. Spontaneous fluctuations in blood-oxygen-level-dependent fMRI (BOLD fMRI) can indirectly measure neuronal activity. Studies have suggested that the fMRI-derived metrics may be indicative of the epileptogenic zone localization, however the potential for fMRI to reflect and lateralize the hypometabolic FDG-PET regions remains underdetermined. Here, both static and dynamic fMRI-derived metrics were calculated and we assessed their potential for lateralizing the hypometabolic FDG-PET regions in patients with unilateral focal epilepsy.