This 3-tissue compartment model separates free tracer C1(t) and non-specifically bound tracer C3(t) in the non-displaceable compartment. K1 and k2 describe the exchange between arterial plasma and tissue, k3 and k4 between free and specifically bound tracer C2(t) in tissue, and k5 and k6 between free and non-specifically bound tracer.
Differential Equation of the Mass Balance
with input curve Cp(t).
Operational Model Curve
with the concentration CB(t) of tracer in whole blood, and the blood volume fraction vB.
Parameter Fitting using Distribution Volumes
This variant of the 3-Tissue Compartment Model uses three distribution volumes as fitting parameters: the distribution volume of free tracer (K1/k2), of non-specifically bound tracer Vns (= (K1*k5)/(k2*k6)), and specifically bound tracer Vs (=(K1*k3)/(k2*k4)) instead of k2, k4 and k6.