2-[fluorine-18] fluoro-2-deoxy-D-glucose PET scan of the brain in maple syrup urine disease

2-[fluorine-18] fluoro-2-deoxy-D-glucose positron emission tomography (F-18 FDG PET) and MRI brain scans revealed bilateral basal ganglia, thalami, and brain-stem involvement in a 6-year-old girl with maple syrup urine disease, an autosomal-recessive disorder caused by the deficiency of branched-chain ketoacid dehydrogenase. She had acute metabolic decompensation as a neonate and later showed a slowly progressive encephalopathic course. The F-18 FDG PET study showed functional changes that were more extensive than the structural abnormalities shown by MRI and proved to be more sensitive and accurate in delineating the areas involved and better correlated with the patient's clinical course.