PURPOSE: With contrast-enhanced MRI (ceMRI), Normal myocardium to null the signal of is difficult to decide if diffuse and mild myocardial enhancement is present. We studied the characteristics of enhancement in DCMP by ceMRI with a fixed inversion time (TI). METHOD AND MATERIALS: Thirty nine patients (male 26, female 13, mean age 59짹12 yrs) with DCMP and normal coronary artery proven by conventional coronary angiography and 30 patients with myocardial infarction underwent ceMRI. TI was fixed at 280 ms to apply the same nulling effect on normal myocardium 10 minutes after contrast administration of Gd-DPTA at 0.2mmol/kg. The signal intensity of skeletal muscles on the chest wall (SIsm) was used as reference. The ratio of SI of remote myocardium (SIrm) from hyperenhanced infarction to SIsm was compared with the ratio of SI of abnormally enhanced myocardium (SIem) to SIsm and the ratio of SI of nonenhanced myocardium (SInem) to SIsm in DCMP. RESULTS: Visual assessement of the myocardium in patients with DCMP resulted in no enhancement in 13 (33%) patients, and enhancement in 26 (67%), while all patients with infarction showed hyperenhancement on the infarcted region. Enhancement in DCMP was mild to moderate in 18 (46%), strong in 4 (10%) and both in 4 (10%). The SIem/SIsm in DCMP was 4.02짹2.46 in average, while the SIrm/SIsm in infarction showed 0.79짹0.91 which was nearly same as SInem/SIsm of 0.79짹0.67 in DCMP without enhancement. The SIem/SIsm of mild to moderate enhancement in DCMP was 3.68짹1.78 and that of hyperenhancement was 5.55짹3.38. In 26 patients with myocardial enhancement, enhancement was frequent on basal (42.3%) and septal (42.3%) area. Diffuse transmural enhancement (46.2%) was more frequent than middle layer enhancement (34.6%). EF and EDV of the LV showed no significant correlation with the presence, degree, and pattern of abnormal myocardial enhancement in DCMP. CONCLUSIONS: The mild to moderate degree of diffuse transmural or middle layer enhancement especially on the basal septum is a frequent and characteristic enhancement pattern of myocardium in DCMP patients.