Myocarditis comprises many clinical presentations ranging from asymptomatic to
sudden cardiac death. The history, physical examination, cardiac
biomarkers, inflammatory markers, and electrocardiogram are usually helpful in the initial assessment of suspected acute
myocarditis. Echocardiography is the primary tool to detect ventricular wall motion abnormalities,
pericardial effusion, valvular regurgitation, and impaired function. The advancement of cardiac magnetic resonance (CMR) imaging has been helpful in clinical practice for diagnosing
myocarditis. A recent Scientific Statement by the American Heart Association suggested CMR as a confirmatory test to diagnose acute
myocarditis in children. However, standard CMR parametric mapping parameters for diagnosing
myocarditis are unavailable in pediatric patients for consistency and reliability in the interpretation. The present review highlights the unmet clinical needs for standard CMR parametric criteria for diagnosing acute and chronic
myocarditis in children and differentiating dilated chronic
myocarditis phenotype from
idiopathic dilated cardiomyopathy. Of particular relevance to today's practice, we also assess the potential and limitations of CMR to diagnose acute
myocarditis in children exposed to
severe acute respiratory syndrome coronavirus-2
infections. The latter section will discuss the multi-inflammatory syndrome in children (MIS-C) and
mRNA coronavirus disease 19 vaccine-associated
myocarditis.