A proof of concept report of ASL MRI and 18F-FDG pet in limbic encephalitis

Autoimmune limbic encephalitis (LE) is a condition characterized by seizures and cognitive dysfunction. Fluorine-18 Fluorodeoxyglucose (18F-FDG PET) has proved to be an important diagnostic and prognostic tool because it may detect brain metabolism in the earlier phases of the disease. Two main 18F-FDG PET patterns have been reported: a neurodegenerative one and a mixed hypermetabolic/hypometabolic. Arterial Spin Labelling (ASL) MRI reveals brain perfusion, that matches brain metabolism because they are strongly coupled. The aim of the present study was to evaluate patients with LE with both techniques.