Fig. 1.

Compartment models for describing hepatic [¹¹C]erlotinib disposition. X_blood, X_liv, X_hep, X_ih, and X_eBD/GB represent the amount of [¹¹C]erlotinib in the blood, liver tissue, hepatocyte compartment, intrahepatic bile duct, and compartment representing the extrahepatic bile duct and gall bladder, respectively. The rate constants defining the exchange of [¹¹C]erlotinib between blood and liver tissue are defined by k₁ (min⁻¹) and k₂ (min⁻¹). a In the four-compartment model (4C model), k₃ (min⁻¹) is the rate constant describing transfer from liver tissue to the intrahepatic bile duct, and k₅ (min⁻¹) is the rate constant describing transfer from the intrahepatic bile duct to the extrahepatic bile duct and the gall bladder. This model is divided into two main regions of interest: the liver, composed of the blood, hepatocyte, and intrahepatic bile duct compartments; and the extrahepatic bile duct and gall bladder (eBD/GB), composed of the extrahepatic bile duct and gall bladder compartment. b In the three-compartment model (3C model), k₃ (min⁻¹) is the rate constant describing transfer from the liver to the extrahepatic bile duct and gall bladder. The 3C model is divided into two main regions of interest: the liver, composed of blood and liver tissue compartments; and eBD/GB, which is composed of the extrahepatic bile duct and gall bladder compartment