A new graphic plot method for determination of neuroreceptor binding in PET studies

In positron emission tomography (PET) studies with radioligands for neuroreceptors, the kinetics of tracers has been described by the standard two-tissue compartment model which includes compartments of nondisplaceable binding and specific binding to receptors. Previously, we have developed a graphic plot method to determine the influx rate constant (K1) and distribution volume for tracers which show kinetics according to the one-tissue compartment model [1]. In this plot, Y(t) is the ratio of brain tissue activity (CT) to time-integrated arterial input function (CP), and X(t) is the ratio of time-integrated brain tissue activity to time-integrated arterial input function. The y-intercept of linear regression of plots represents the K1, and x-intercept represents the distribution volume. In the present study, we have applied this graphic plot method to PET data of [C-11]FLB457 which is a radioligand for extrastriatal dopamine D2 receptors in order to determine the nondisplaceable and specific binding.Neuroreceptor Mapping 200