Estimation of the Myocardial Extracellular Volume Fraction from Dynamic Contrast-Enhancement Measurements and Comparison with Partition Coefficient Measurements

Introduction: Recent studies have shown that myocardial T1 after administration of an extracellular Gd-based contrast agent and the myocardial partition coefficient represent novel biomarkers of diffuse fibrosis, which may be not recognized by standard methods for imaging delayed contrast enhancement [1-2]. Such novel markers of diffuse fibrosis and remodeling of the extracellular matrix could be useful for detecting and monitoring the progression of cardiac diseases and heart failure, and reduce the need for myocardial biopsies. The myocardial partition coefficient, when corrected by the blood hematocrit, provides an estimate of the extracellular volume fraction (vec), which is independent of the contrast dosage. It is nevertheless time-consuming to accurately measure the myocardial partition coefficient by multiple preand post-contrast T1 measurements. In this study we investigated the possibility of determining the vec with a single dynamic imaging acquisition at rest using a bolus injection of an extracellular contrast agent [3].