Discordance between FDG uptake and technetium-99m-HMPAO brain perfusion in acute traumatic brain injury

A 28-yr-old woman who sustained a mild traumatic brain injury had an 18F-fluorodeoxyglucose (FDG) PET brain study using coincidence imaging performed on a dual-head gamma camera (MCD version; ADAC, Milpitas, CA) followed 24 hr later by 99mTc-hexamethyl propyleneamine oxime SPECT brain perfusion imaging using a triple-head gamma camera (TRIONIX, Twinsburg, OH). The results of the SPECT brain perfusion study demonstrated decreased frontoparietal cortical brain perfusion, whereas 18F-FDG cerebral uptake was normal. Neuropsychological evaluation suggested frontal lobe involvement. This case demonstrates the possibility of discordance between brain perfusion and glucose uptake in acute mild traumatic brain injury.