T1 and T2 mapping cardiovascular magnetic resonance imaging techniques reveal unapparent myocardial injury in patients with myocarditis

This study evaluated the ability of T1 and T2 mapping cardiovascular magnetic resonance (CMR) to detect myocardial injury in apparently normal myocardium of patients with myocarditis. We included 20 patients with “infarct-like” acute myocarditis who had typical focal myocardial lesions on late gadolinium enhancement (LGE) images as well as 20 healthy controls. The CMR protocol consisted of a standard myocarditis protocol which was combined with T1 (modified Look-Locker inversion recovery (MOLLI) with a 3(3)5 scheme and T2 mapping (hybrid gradient- and spin-echo multi-echo sequence, GraSE). First, LGE images were used to depict focal myocardial injury and apparently normal, remote myocardium. Second, native T1, T2 and ECV values were obtained in focal lesions but also in apparently normal myocardium. Third, native T1, T2 and ECV values ≥2 standard deviations above reference values obtained in healthy volunteers were used to quantify myocardial injury in patients with myocarditis. Apparently normal myocardium had significantly higher median native T1 [1095 (1055–1148) ms] and ECV [34 (32–35) %] values compared to reference values from healthy volunteers, which were 1051 (1021–1064) ms (p