Clinical evaluation of interictal fluorine-18-fluorodeoxyglucose PET in partial epilepsy

Interictal [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) is useful in presurgical evaluation of medically refractory partial epilepsies. Limited replicability of image interpretation may restrict this application. We investigated interpretation replicability in 241 18F-FDG studies performed with three different tomographs in partial epilepsy patients. Two investigators independently interpreted the studies with a standardized evaluation protocol and without knowledge of the subjects. Replicability of these unbiased interpretations in detection of regional hypometabolism was best for studies performed with the highest performance tomograph. Interictal 18F-FDG studies performed with this tomograph revealed regional hypometabolism in 62% of patients who had normal cerebral magnetic resonance imaging (MRI). Replicability of interpretations in detecting regional hypometabolism was adequate for clinical application of interictal 18F-FDG studies performed with any of the tomographs.