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

Purpose: We sought to use non-contrast-enhanced T mapping to determine the native T 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 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 value was measured in each segment. The T values of septal segments with LGE were compared with those of the septal segments without LGE, the minimum T value of each patient, and the T values of the normal septal myocardium.

Results: Late gadolinium-enhancement was present in 12 septal segments (24.0%) from 10 patients (40.0%). T 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 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 mapping can be used for assessment of myocardial fibrosis associated with DCM by using the appropriate threshold.