Abstract: Objective: To study the use of ¹¹C-FMZ PET in detecting residual neuronal function in vegetative state patients after traumatic brain injury. Methods: Four cases of vegetative state patients after traumatic brain injury were enrolled,and 7 normal volunteers were served as controls. ¹¹C-FMZ PET was performed to detect the standardized uptake value（SUV） of cortex of both hemispheres. SUV ratio (SUVR ) was obtained when SUV of the cerebral hemispheres was divided by SUV value of reference tissue, the pons. SUVRs of affected side and unaffected side were compared, as well as between patients and volunteers. Results: SUVRs of cerebral cortex of affected side were significantly lower than those of unaffected side and those of normal controls (P<0.05): frontal lobe (4.70 vs. 5.08, 7.23); temporal lobe (4.56 vs. 4.88, 7.05); parietal lobe (4.80 vs. 5.13, 6.81); occipital lobe (4.97 vs. 5.38, 7.42); cerebral hemisphere (4.75 vs. 5.12, 7.12). Conclusions: ¹¹C-FMZ PET can be used to observe the residual neuronal function in vegetative state patients after traumatic brain injury.

Key words: Cerebral trauma, egetative state, ¹¹C-flumazenil positron emission tomography, Neuronal function