[T1 and T2 mapping: new perspectives in cardiac magnetic resonance imaging]

Cardiac magnetic resonance (MR) imaging is currently considered the gold standard for characterizing changes in myocardial structure, in particular to assess myocardial edema and focal fibrosis. In spite of this potential capability, the traditional MR sequences usually employed for these purposes have significant limitations and provide only qualitative information. Recent developments in cardiac MR imaging techniques currently provide clinically-feasible mapping of T1 and T2 relaxation times, thus providing a quantitative assessment of the parameters of interest. Myocardial edema can be evaluated using T2 mapping techniques. These have shown a superior performance compared to the traditional T2-weighted and STIR sequences, both in acute inflammatory cardiomyopathies and in acute ischemic injury. T1 mapping techniques, performed both with and without contrast medium, enable to quantify diffuse myocardial fibrosis and to assess myocardial edema and infiltration. This article will review current methodologies for cardiac T1 and T2 parametric mapping and their potential and limitations in the assessment of myocardial damage.