Diagnostic approach and role of MRI in the assessment of acute myocarditis.

The diagnosis of acute myocarditis can be challenging, primarily because of the clinical diversity at presentation, the nonspecificity of traditional noninvasive tests, as well as the poor diagnostic yield and potential complications inherent with endomyocardial biopsy. Contrast-enhanced and nonenhanced cardiac magnetic resonance imaging (MRI) is emerging as an imaging modality of choice to diagnose and monitor the progression of myocarditis. MRI is nonionizing, non-nephrotoxic, and in comparison to coronary angiography, allows the clinician to rapidly eliminate irreversible ischemic injury (acute coronary syndrome) from the differential diagnosis. This timely review discusses the advantages and limitations of cardiac MRI over alternative diagnostic modalities and offers a practical approach to the contemporary diagnosis and assessment of acute myocarditis.