Figure 1

Model comparison. Curve (a) Trapped tracer activity (in arbitrary unit) versus time (in minutes) from Equation 3, assuming irreversible trapping, and the input function of Vriens et al. for ¹⁸F-FDG was used [15]. Curve (b) (full line) Z-F function, i.e. A_Tot(t = 60) * exp(−λt) (the value for A_Tot(t=60) was taken from curve a). Curve (c) (dotted line) Z-F function with A_Tot(t = 84) (instead of A_Tot(t = 60)) that gives similar AUC for the two models.