Objective: To explore the application value of positron emission tomography (PET) in the localization of magnetic resonance imaging (MRI)-negative epileptogenic focus.
Methods: Brain images of 18fluoro-2-deoxy-D-glucose (18F-FDG) and 13N-NH3·H2O-PET, MRI and video electroencephalography (VEEG) were obtained in 65 patients. Preoperative and postoperative localizations were compared in MRI-negative patients. And the results of PET and VEEG were compared between the MRI-positive and MRI-negative groups.
Results: MRI scans were normal in 26 cases and abnormal in 35 cases. Sixty-one patients had interictal epileptiform discharge on VEEG (brain regions, n = 12; multiple brain areas, n = 16; hemisphere, n = 13; unspecified location, n = 20) and interictal PET imaging (brain regions, n = 23; multiple brain areas, n = 28; hemisphere, n = 5; unspecified location, n = 6). And 17 MRI-negative patients underwent operations and 12 of them reached the Engels I-II level standard. Both PET and VEEG were compared between the MRI-positive and MRI-negative groups. No significant differences existed between two group (P < 0.05). A comparison of PET and VEEG showed statistical significance in two group (P > 0.05).
Conclusions: PET imaging is both sensitive and effective in the detection and localization of epileptogenic foci. Especially for MRI-negative cases, it is an indispensable tool of localizing epileptogenic foci.