Rapid innovations in cardiovascular magnetic resonance (CMR) now permit the 
routine acquisition of quantitative measures of myocardial and blood T1 which 
are key tissue characteristics. These capabilities introduce a new frontier in 
cardiology, enabling the practitioner/investigator to quantify biologically 
important myocardial properties that otherwise can be difficult to ascertain 
clinically. CMR may be able to track biologically important changes in the 
myocardium by: a) native T1 that reflects myocardial disease involving the 
myocyte and interstitium without use of gadolinium based contrast agents (GBCA), 
or b) the extracellular volume fraction (ECV)-a direct GBCA-based measurement of 
the size of the extracellular space, reflecting interstitial disease. The latter 
technique attempts to dichotomize the myocardium into its cellular and 
interstitial components with estimates expressed as volume fractions. This 
document provides recommendations for clinical and research T1 and ECV 
measurement, based on published evidence when available and expert consensus 
when not. We address site preparation, scan type, scan planning and acquisition, 
quality control, visualisation and analysis, technical development. We also 
address controversies in the field. While ECV and native T1 mapping appear 
destined to affect clinical decision making, they lack multi-centre application 
and face significant challenges, which demand a community-wide approach among 
stakeholders. At present, ECV and native T1 mapping appear sufficiently robust 
for many diseases; yet more research is required before a large-scale 
application for clinical decision-making can be recommended.