FIGURE 2.

(Top) Data are acquired at single bed position (left) and reconstructed into multiframe dynamic images (middle), on which regions of interest are drawn to create time–activity curves (right). Blood time–activity curve peaks early in scan (red arrow, corresponding to early dynamic frames), whereas tumor activity peaks later (blue arrow, corresponding to later dynamic frames). (Middle) In this schematic overview of the approach to kinetic analysis, raw whole-blood time–activity curve must be partitioned into plasma vs. red blood cell activity and corrected for metabolites to obtain plasma time–activity curve, which is then used as input to kinetic modeling process. Dynamic tissue time–activity curves act as standard of truth against which model estimates are compared in iterative process of kinetic parameter estimation. (Bottom) Kinetic parameter estimation (model-generated tissue curve) improves through model optimization as iterations increase.