T2-weighted and delayed enhancement MRI of eosinophilic myocarditis: relationship with clinical phases and global cardiac function

To evaluate the usefulness of magnetic resonance imaging (MRI) for detection and quantification of myocardial damage related to clinical phases and cardiac function during eosinophilic myocarditis. Four eosinophilic myocarditis patients received seven MRI studies. The left ventricular myocardium was divided into 48 layers, and we quantified the extent of abnormal intensity detected by T2-weighted or delayed enhancement MRI relative to the clinical phase and global cardiac function. T2-weighted imaging detected extensive myocardial hyperintensity during the acute phase of eosinophilic myocarditis. Diffuse myocardial delayed enhancement was observed in one patient during the acute phase, but not in the other. Little or no hyperintensity was detected by T2-weighted imaging or myocardial delayed enhancement during the convalescent phase. The extent of hyperenhancing myocardial layers was inversely correlated with the ejection fraction (EF) (r = -0.87). MRI can evaluate the presence and extent of myocardial damage related to the clinical phases and EF during eosinophilic myocarditis.