Figure 2.

Two-compartment kinetic model used to describe the kinetics of contrast media transport from the plasma space into the interstitial fluid. The endothelial transfer coefficient K^PS [μL/(min · 100 cm³)] denotes the clearance of contrast medium from plasma to interstitial water. Potential reflux of contrast media molecules from interstitial fluid back to plasma, denoted as the rate constant k (min⁻¹), was not resolvable in the short, one hour time course of these experiments and was therefore set to zero. The box around the plasma compartment denotes a forcing function representing the mono-exponential disappearance of MMCM from the blood. The combined kinetics of both compartments, when considered together, reflect the dynamic response of the entire tissue/tumor to contrast medium enhancement.