Non-contrast-enhanced T1 Mapping of Dilated Cardiomyopathy: Comparison between Native T1 Values and Late Gadolinium Enhancement

Purpose: We sought to use non-contrast-enhanced T-1 mapping to determine the native T-1 values required to identify myocardial fibrosis in patients with dilated cardiomyopathy (DCM). Methods: A total of 25 patients with DCM and 15 healthy controls were enrolled. All subjects underwent T-1 mapping using modified look-locker inversion recovery, and the patients underwent late gadolinium-enhancement (LGE) imaging. Basal and mid-ventricular levels were divided into eight segments and the T-1 value was measured in each segment. The T-1 values of septal segments with LGE were compared with those of the septal segments without LGE, the minimum T-1 value of each patient, and the T-1 values of the normal septal myocardium. Results: Late gadolinium-enhancement was present in 12 septal segments (24.0%) from 10 patients (40.0%). T-1 values were significantly higher in septal segments with LGE than in those without (1373.7 vs. 1288.0 ms; P = 0.035) or in normal septal myocardium (1209.1 ms; P < 0.01). A receiver operating characteristic analysis revealed the appropriate cutoff value of 1349.4 ms for identifying LGE with a sensitivity of 75% and specificity of 92.1%. When the minimum T-1 value + 1.2 standard deviation (SD) was used as the threshold, the sensitivity was 75% and specificity was 89.5%. Conclusion: Non-contrast-enhanced T-1 mapping can be used for assessment of myocardial fibrosis associated with DCM by using the appropriate threshold.