Histological validation of dynamic-equilibrium CMR. Short-axis pixelwise T1 relaxation time maps at basal (A and B; colors correspond to T1 relaxation time according to colour bar legends), mid (D and E) and apical (G and H) ventricular levels before (A, D, G) and 15-minutes after a bolus of 0.20mmol/Kg Gd-DTPA contrast (B, E, H), were determined from modified Look Locker inversion recovery imaging in order to determine segmental myocardial extracellular volume fraction. Subsequently, patients underwent heart transplantation. Explanted hearts were immediately fixed in 10% buffered formalin and cut at corresponding basal (C), mid (F) and apical (I) ventricular levels. Tissue blocks were taken from each segment before being embedded in paraffin and stained with picrosirius red in order to determine segmental histological collagen volume fraction.