PURPOSE Delayed myocardial enhancement (DE) in the hypertrophic areas of HCMP that likely represent fibrosis has been recently reported. The purpose of our study was to evaluate the relationship of DE to regional left ventricular function using myocardial tagging method. METHOD AND MATERIALS Cine imaging, gadolinium enhancement imaging with inversion recovery fast gradient echo sequence and myocardial tagging (CSPAMM) MRI were performed in 13 patients with HCMP. We analyzed 33 slices of the 13 patients, dividing each slice into 6 segments (total 198 segments). Location (6 segments), degree (mild or high), and pattern of DE were evaluated. End diastolic wall thickness (EDWT) and systolic wall thickening (SWT= end systolic WT-EDWT/EDWT) were measured in each segment on cine MRI. For the evaluation of regional LV function, circumferential strain (Ecc; circumferential shortening) was calculated by analyzing CSPAMM images with HARP software. RESULTS DE occurred in 11(84.6%) of the 13 patients and in 103 (52%) of the 198 segments, with a high frequency of localization in septum and regions where the right ventricle was attached. Circumferential strain (Ecc) was significantly low at the enhanced segments, compared with non-enhanced segments (-13.5짹0.60 vs -19.5짹0.38, p<0.0001). In each segment, Ecc of the group with DE was significantly lower than that of the group without DE (p<0.05). EDWT was thicker and SWT was less degree in enhanced segments than in non-enhanced segments (EDWT: 17.9짹0.59 mm vs 14.4짹0.46 mm, p< 0.0001, SWT: 0.42짹0.03 vs 0.50짹0.03, p= 0.0472). The degree of DE and Ecc shows an inverse correlation. The pattern of DE (ill-defined patchy, focal nodular, or circumferential) is not correlated with Ecc. CONCLUSIONS Delayed myocardial enhancement with various patterns and degrees is commonly found in the patients with HCMP. DE characteristically occurs in hypertrophied areas and the junctions of the septum and RV wall, and correlates inversely with regional LV function by myocardial tagging analysis.