Review the definition and epidemiology of myocarditis. Present the respective values of complementary non-imaging examinations. Define and illustrate MR scan capabilities in diagnosing acute myocarditis. Discuss the clinical interest of systematic MR scan examination.

Myocarditis : definition Inflammation of the myocardium [1] Acute, subacute, or chronic Focal or diffuse Dallas pathological criteria (1986) = first attempt to standardize the histopathological classification of myocarditis. [1] Active myocarditis = inflammatory cellular infiltrate with evidence of myocyte necrosis Inflammatory infiltrate predominantly lymphocytic (55%) Incidence and symptoms Autopsy series have reported myocarditis in up to 22% of young adults presenting with sudden death. [1, 2] Important underlying etiology of dilated cardiomyopathy (9%) [2] Extreme diversity of clinical manifestations ranging from non specific systemic...

Cardiac Magnetic Resonance (CMR) First description of T2-weighted CMR findings in children with myocarditis by Gagliardi et al in 1991 [2] Offers anatomical visualization, quantitative accuracy with interobserver consistency and myocardial tissue analysis. Sensitivity of cardiac magnetic resonance is best within the first 2 weeks of disease onset. [5] Indications (CMR) Consensus for performing CMR if: [2] symptomatic new or persisting symptoms suggestive of myocarditis (dyspnea, orthopnea, palpitations, effort intolerance, malaise, chest pain) clinical evidence for myocarditis Evidence for recent/ongoing myocardial injury (ie, ventricular dysfunction,...

Cardiac magnetic resonance imaging has become a powerful tool in evaluation of patients with suspected acute myocarditis, by being able to identify the presence of edema, hyperemia, necrosis and fibrosis, and by assessing functional and morphological status. Its sensitivity is best within the first two weeks of disease onset. To achieve best diagnostic accuracy for identifying presence of inflammation, systematic use of the Diagnostic CMR Lake Louise Consensus Criteria for myocarditis (presence of ≥ 2 criteria) is recommended. Since some of the abnormalities are typically...

Caroline Lacroix, MD is currently a third-year resident in diagnostic radiology at Centre Hospitalier Universitaire de Sherbrooke. Danny Bélanger, MD, M.Sc is currently a fourth-year resident in diagnostic radiology at Centre Hospitalier Universitaire de Sherbrooke. Philippe Martin, MD is currently a third-year resident in infectious diseases at Centre Hospitalier Universitaire de Sherbrooke. Paul Farand, MD, M.Sc is a cardiologist and an assistant professor at Centre Hospitalier Universitaire de Sherbrooke . François Belzile, MD, is an interventional radiologist, an assistant professor and the director of the...

1. Childs, H. and M.G. Friedrich, Cardiovascular magnetic resonance imaging in myocarditis. Prog Cardiovasc Dis, 2011. 54(3): p. 266-75. 2.Friedrich, M.G., et al., Cardiovascular magnetic resonance in myocarditis: A JACC White Paper. J Am Coll Cardiol, 2009. 53(17): p. 1475-87. 3.Cooper, L.T., Jr., Myocarditis. N Engl J Med, 2009. 360(15): p. 1526-38. 4.Lauer, B., et al., Cardiac troponin T in patients with clinically suspected myocarditis. J Am Coll Cardiol, 1997. 30(5): p. 1354-9. 5.Wassmuth, R. and J. Schulz-Menger, Cardiovascular magnetic resonance imaging of myocardial inflammation....