18),19) Fig. 1 The patterns of delayed hyperenhancement of the heart. HCM: hypertrophic cardiomyopathy, RV: right ventricle, DCM: dilated cardiomyopathy. Although DHE sequences on CMR is widely utilized for assessing regional myocardial fibrosis/scarring this relies on the relative difference in signal intensity between scarred

and the presumed normal adjacent myocardium to generate image contrast. Scar formation in infarcted myocardium is due to replacement of the myocardium with collagen. Such areas of dense fibrosis have a much slower washout rate of gadolinium-based contrast than healthy myocardium, thus resulting in markedly increased signal intensity Inhibitors,research,lifescience,medical on T1-weighted Inhibitors,research,lifescience,medical imaging within the infarcted myocardium. A key shortcoming to delayed contrast-enhanced CMR is that it relies on the assumption that the surrounding and remote myocardium is truly normal and that there is a distinct difference in gadolinium washout kinetics. Because collagen deposition in nonischemic cardiomyopathy is commonly diffuse, the technique of delayed contrast enhancement often shows no regional scarring. However, T1 mapping allows for the calculation of the relaxation time of each pixel within a parametric

image, which can detect subtle differences in regional tissue characteristics. Therefore, Inhibitors,research,lifescience,medical contrast resolution not dependent on relative differences in signal intensity as it is with DHE scar imaging. Therefore, this newer CMR technique may prove to be useful in evaluating various reversible cardiomyopathies. Several techniques for measuring myocardial T1 to identify myocardial fibrosis with T1 mapping have been described in the literature.18),20),21) Reversible Cardiomyopathies Acute myocarditis Myocarditis, immune Inhibitors,research,lifescience,medical and viral mediated cardiac damage, is about 15% of the patients with a new onset Inhibitors,research,lifescience,medical dilated cardiomyopathy or heart failure.22) Despite

up to 50% of patients have no identifiable etiology with a full and complete evaluation, the determination of the etiology is important in the treatment and prediction of the prognosis.22) Acute viral myocarditis Acute viral myocarditis is a common cause aminophylline of acute myocarditis and Coxsackie B virus is the most common cardiotropic virus. Although the clinical presentations are variable, the majority of patients have antecedent flulike symptoms. Echocardiographic examination is helpful in the RAD001 purchase detection of heart failure. All cardiac chambers can be dilated in the severe and diffuse myocarditis. LV dysfunction with segmental involvement reflects the focal involvement of myocarditis. Echocardiography can detect other structural abnormalities including intracardiac thrombi, valvular regurgitation, and pericardial involvement. Endomyocardial biopsy showed myocardial inflammation and edema. CMR is a good diagnostic modality in the detection of acute myocarditis.