T1 Mapping in Heart Failure

Cardiovascular magnetic resonance (CMR) is increasingly used in the assessment of heart failure and cardiomyopathy because it offers uniquely precise noninvasive phenotypic characterization. Beyond enabling highly accurate and reproducible quantification of ventricular volumes and ejection fraction, the power of this technique was further established by the application of late gadolinium enhancement to identify scar, which has both diagnostic and prognostic use. Although this regional replacement fibrosis can be identified by late gadolinium enhancement and is clearly associated with adverse outcome in several cardiomyopathies,1,2 it is mostly irreversible. In contrast, reactive interstitial fibrosis, generally a precursor of replacement fibrosis, is potentially reversible. In reality, reactive fibrosis and replacement fibrosis are on a continuum. It is appreciated that a significant myocardial process is not identified by conventional late gadolinium enhancement CMR (in the absence of adequate expansion of the extracellular space) in a variety of cardiac conditions and that this undetected common pathology is diffuse interstitial fibrosis.Article see p 1056T1 mapping to assess extracellular volume (ECV) as a biomarker for diffuse myocardial fibrosis is currently a hot topic in the literature because this technique has emerged from its infancy and developed during the past decade, proliferating during the past 3 years.2 T1 maps can be produced of the native T1 value of tissue (informing with regard to both the myocyte and the interstitium) or after gadolinium contrast administration (enabling quantification of the extracellular space). The current gold standard technique for ECV quantification is equilibrium contrast CMR as described by Flett et al,3 with continuing development.4,5 T1 mapping may be sensitive to myocardial involvement under several conditions long before other changes are evident by biochemical, imaging or clinical …