Myocardial extracellular volume fraction (ECV) measurements based on T1-mapping in healthy monozygotic twins - another similarity or rather disagreement in twins?

Background The T1-mapping MOLLI technique has already proved to be a robust and reproducible technique for myocardial extracellular volume fraction (ECV) estimation in both healthy individuals and patients with different cardiomyopathies. Monozygotic twins share the same DNA information and frequently grow up in a similar environment. However, epigenetic as well as environmental factors may lead to major differences in clinical phenotype, organ function as well as character and behaviour. Therefore, monozygotic twins provide a very interesting and attractive research model regarding specific organ structure, metabolism and function. With this study, we aimed at evaluating possible ECV measurement variations within pairs of healthy monozygotic twins.