Cerebral glucose metabolic rates after 30 and 45 minute acquisitions: a comparative study

This study was undertaken to determine if measurements of absolute regional cerebral metabolic rate for glucose (rCMRglc) and variance of rCMRglc are independent of time between 30 and 45 min following injection of the radiotracer. Sixteen subjects received two sets of 18FDG PET scans commencing 30 and 45 min following intravenous injection of 18FDG. No statistically significant differences were detected in either absolute rCMRglc or rCMRglc variance between the two sets of scans. These data demonstrate that for most FDG PET studies, scanning can commence 30 min after injection of the radiotracer without compromising the metabolic data.