Baseline and Follow-Up Cardiac Magnetic Resonance Imaging Findings in Children with Acute Myocarditis and Factors Associated with Late Gadolinium Enhancement

<b>Objectives</b>: Cardiac magnetic resonance (CMR) plays a central role in the diagnosis and follow-up of acute myocarditis (AM). In this study, we aimed to evaluate baseline and follow-up CMR findings and associated factors in children with AM. <b>Methods</b>: A retrospective analysis of CMR in pediatric patients with clinical presentations suggestive of myocarditis was performed. Patients' demographic characteristics, clinical data, and diagnostic test results, as well as CMR imaging results, were evaluated. <b>Results</b>: All 28 pediatric patients with acute myocarditis included in this study had late gadolinium enhancement (LGE) on initial CMR imaging. Additionally, 14 (50%) patients had increased extracellular volume (ECV), 4 (50%) patients had focal high-intensity areas on T2 STIR images, 15 (53.6%) patients had increased T1 relaxation time, and 17 (60.7%) patients had increased T2 relaxation time. At a median follow-up CMR of 6 months, 24 (85.7%) patients had LGE, 5 (17.9%) patients had increased ECV, and 7 (25%) patients had increased T1 relaxation time, while other parameters showed complete recovery. Baseline troponin and CRP levels, T1 relaxation time, T2 relaxation time, and increased ECV were found to be factors associated with the resolution of LGE. <b>Conclusions</b>: Baseline troponin and CRP levels, as well as T1 relaxation time, T2 relaxation time, and increased ECV, were effective parameters that seemed to predict the resolution of LGE. Larger and multicenter experiences would confirm these hypotheses.