Key results of a T1 mapping (A) and equilibrium contrast MRI (B) study performed by Iles et al. and Flett et al, respectively. Both studies show the correlation between the used technique and collagen content in the myocardium. In the graph of the T1 mapping study (A) the mean post-contrast T1 time, of the myocardium after a bolus injection of a Gd-based CA is plotted against the myocardial collagen content obtained by biopsy. In the graph of the equilibrium contrast study (B) the calculated volume of distribution in the myocardium, based on the mean T1 determined by T1 mapping under continuously infusion of a Gd-based CA during the whole experiment, is plotted against the myocardial collagen volume fraction obtained from biopsy samples