The Promise of Myocardial Fibrosis Assessment by T1 Mapping

Two intertwined needs have promoted the development of T1 mapping in cardiac magnetic resonance (CMR) during the past decade. The first need relates to the desire for greater spatial granularity as investigators venture outside the infarct- and scar-sizing paradigm to probe the regional heterogeneity of myocardial damage associated with diverse disease processes (1-3), the substrate of arrhythmias (4,5), and the possibility of CMR-guided arrhythmia ablation (6), as well as stem cell therapy (7). The second need, also rooted in the desire to investigate tissue structure using CMR, results in large part from the dependence on contrast kinetics that imposes significant limitations to a more complete understanding of basic cardiac disease processes (8,9). In this issue of iJACC, the report by Puntmann et al. (10) gets us closer to both goals by demonstrating that T1 mapping, carefully performed at 3-T, not only advances our knowledge of differences in the size and/or type of myocardial extracellular space associated with different diseases, but perhaps allows us to perform such assessment without or before contrast administration.