Impact of reversible trapping of tracer and the presence of blood metabolites on measurements of myocardial glucose utilization performed by PET and 18F-fluorodeoxyglucose using the Patlak method.

In this study we demonstrated that significant egress of FDG from myocardium occurs within the first hour after tracer injection leading to nonlinear Patlak plots. There are also significant amounts of acidic FDG metabolites present in the blood. However, the impact of these metabolites on the estimates of myocardial glucose utilization (MGU) is negligible. Although further studies will be required to elucidate the reason for the egress of tracer from myocardium, not accounting for it will result in erroneous estimates of MGU.