A pattern-based approach to assessment of delayed enhancement in nonischemic cardiomyopathy at MR imaging

Although delayed contrast material-enhanced cardiac magnetic resonance (MR) imaging has traditionally been used to evaluate ischemic disease and myocardial viability, it is increasingly being used in the evaluation of nonischemic cardiomyopathies. Unlike myocardial infarction, which demonstrates subendocardial or transmural delayed contrast enhancement in a vascular distribution, nonischemic cardiomyopathies demonstrate enhancement that is not limited to a vascular territory. In combination with other cardiac MR imaging features, the location (subendocardial, transmural, subepicardial, or mesocardial) and pattern (patchy or diffuse) of abnormal delayed myocardial enhancement allow differentiation between ischemic (infarct-related) and nonischemic cardiomyopathies and, in cases of nonischemic cardiomyopathy, narrowing of the differential diagnosis. With use of a structured approach, delayed contrast-enhanced cardiac MR imaging can be helpful in the early detection and appropriate treatment of nonischemic cardiomyopathies.