NONINVASIVE QUANTITATIVE FLUORODEOXYGLUCOSE PET STUDIES WITH AN ESTIMATED INPUT FUNCTION DERIVED FROM A POPULATION-BASED ARTERIAL BLOOD CURVE

The authors have developed a technique to estimate input functions fro m a population-based arterial blood curve in positron emission tomogra phy (PET) studies with fluorine-18 fluorodeoxyglucose (FDG). A standar dized pump injection was used in 34 subjects. A population-based blood curve was generated based on the first 10 subjects. In the remaining 24 subjects, an estimated input function (EIFa) was obtained by scalin g the population-based curve with two arterial blood samples, one obta ined at 10 minutes and the other at 45. Time integrals for EIFa and th e real arterial input function (RIF) were in excellent agreement (r = .998, P < .0001). Cerebral metabolic rates for glucose calculated with EIFa and RIF and the autoradiographic method also correlated excellen tly (r = .992, P < .0001). Analogous correlations were achieved with a rterialized venous samples as scaling factors. These results suggest t hat individually scaled, population-derived input functions may serve as an adequate alternative to continuous arterial blood sampling in qu antitative FDG-PET imaging.