Review of T1 Mapping Methods: Comparative Effectiveness Including Reproducibility Issues

Myocardial T1 mapping by cardiovascular magnetic resonance (CMR) is a key emerging biomarker for quantification of myocardial disease. Native myocardial T1 changes with fat content, iron content, and increased myocardial extracellular water (oedema, focal or diffuse fibrosis, amyloidosis). With the addition of a contrast agent, the extracellular volume (ECV) can be estimated, a robust measure of interstitial space expansion. A number of cardiac T1 mapping methods are currently being used; a selection of these is described. Factors affecting the accuracy, precision and reproducibility of these methods are discussed, including the impact these will have in certain clinical circumstances. Challenges for delivery of T1 mapping to healthcare are examined, including validation, quality control, and protocol transfer between MR systems. As the technique becomes established, key methodology considerations for early adopters are highlighted.