AIF plus TRF calculated for K
= 0.3 ml/min/ml, k
= 0.5 /min, k
= 0.08 /min. The TRF does not become linear at later times but exhibits a visible curvature. However, the slope at some time point t
0 = 60 min in this example) is nearly identical to the slope of the secant connecting the boundary points of a finite time interval centered at t
0. The AIF is scaled such that c
0) = 1. The data accessible in a DTP measurement are indicated by the square plotting symbols. For further details, see the main text.