Three-compartment modeling of chronic myocardial infarction gadolinium kinetics

Introduction The mechanism behind late gadolinium-enhanced (LGE) chronic myocardial infarct (MI) imaging is widely thought to be an increased gadolinium (Gd) concentration due to fibrotic tissue. Several groups have employed T1 measurements to measure the partition coefficient (ratio of tissue-to-blood Gd-concentrations) using a twocompartment model. A three-compartment model yields not only information about flow of Gd from the capillaries to the intracellular space, but in the case of chronic MI to fibrotic tissue and in the case of acute MI in the myocytes themselves. With model inputs of the LV bloodpool and tissue Gd-concentrations, the model yields transfer constants (K) between the compartments, compartment fractional volumes (v) and Gd-concentrations curves for tissue blood plasma, the extravascular extracellular space (EES) and fibrotic tissue. A detailed model may not only be useful to detect and characterize MI, but non-ischemic cardiomyopathies with global or diffuse fibrosis.