Discordance between F-18 fluorodeoxyglucose uptake and contrast enhancement in a brain abscess.

A 29-year-old human immunodeficiency virus-negative intravenous drug abuser with a right hemispheric staphylococcal brain abscess underwent PET imaging of 18F-fluorodeoxyglucose (FDG) brain uptake. Diffuse right cortical hypometabolism was noted, as well as crossed cerebellar diaschisis. Unlike previous PET findings on FDG uptake in a brain abscess, however, the most intense uptake of FDG was found within the abscess and not in the contrast-enhancing walls.