Figure 1 : Three compartment model used to quantify cardiac HED density and flux.

Cp = plasma activity, K1 = transfer constant from plasma to tissue for receptor-containing and reference tissues, respectively (ml/g/min), k2 = transfer constant from tissue to plasma for receptor-containing tissues (per minute), k3, k4 = transfer constants between second and third compartments (per minute). K3 = (1/V2) kon Bmax and  k4=koff.

Bmax (RATIO OF RECEPTOR DENSITY TO BINDING CONSTANT (Kd)