Diagnostic value of cardiovascular magnetic resonance in children with myocarditis

Abstract

Objective To determine the diagnostic value of cardiovascular magnetic resonance (CMR) in children with myocarditis. Methods A total of 27 children with myocarditis were examined with cardiac MRI, including 16 new-onset cases and 11 chronic cases, as well as 14 cases with non-myocarditis. Sequences included SSFP in axial, two chamber, four chamber and short axis, T2-weighted triple inversion recovery, T1-weighted spin echo before and after gadolinium injection, and inversion recovery-gradient echo after gadolinium injection(late gadolinium enhancement, LGE) in axial and short axis. Qualitative and quantitative image analysis was performed to obtain focal T2 signal intensity and early enhancement signal intensity(SI) ratio of myocardium to skeletal muscleon EGE and LGE.The sensitivity, specificity and accuracy were calculated.Mann-Whitney and χ2 test were used for statistical comparison. Results The median value of EF was 60.20% (44.40%, 70.20%), median value of T2W SI ratio was 2.50(2.04, 3.79),and there were 13 cases with LGE positive findings in myocarditis group. The median value of EF was 73.60% (65.40%, 75.85%), the median value of T2WI SI ratio was 1.85(1.77, 2.15), and one case presented LGE positive sign in non-myocarditis group. There were significant statistical differences between the two groups (Z=-2.94,-2.52, χ2=5.19, P<0.05). The sensitivities for T2WI, EGE, LGE were 81.5%(22/27), 14.8% (4/27) and 48.1% (13/27) respectively. The specificities for T2WI, EGE, LGE were 57.1% (8/14), 100.0% (14/14) and 92.9%(13/14) respectively. The diagnostic accuracies for T2WI, EGE, LGE were 73.2%(30/41), 43.9%(18/41) and 63.4%(26/41) respectively. The best diagnostic performance was obtained when any-two of the three sequences were positive in the same patient, yielding a 51.9%(14/27)sensitivity, 92.9%(13/14) specificity, and 65.9% (27/41) diagnostic accuracy. Conclusions The combined CMR approach using T2- weighted imaging, early and late gadolinium enhancement, provides a high diagnostic accuracy and is a useful tool in the diagnosis and assessment of children with myocarditis. Key words: Magnetic resonance imaging; Myocarditis; Child