Native myocardial T1 mapping using inversion recovery T1-weighted turbo field echo sequence.

Abstract

This study proposes the use of the inversion recovery T₁-weighted turbo field echo (IR-T₁TFE) sequence for myocardial T₁ mapping and compares the results obtained with those of the modified Look-Locker inversion recovery (MOLLI) method for accuracy, precision, and reproducibility. A phantom containing seven vials with different T₁ values was imaged, thereby comparing the T₁ measurements between the inversion recovery spin-echo (IR-SE) technique, MOLLI, and the IR-T₁TFE. The accuracy, precision, and reproducibility of the T₁-mapping sequences were analyzed in a phantom study. Fifteen healthy subjects were recruited for the in vivo comparison of native myocardial T₁ mapping using MOLLI and IR-T₁TFE sequences. After myocardium segmentation, the T₁ value of the entire myocardium was calculated. In the phantom study, excellent accuracy was achieved using IR-T₁TFE for all T₁ ranges. MOLLI displayed lower accuracy than IR-T₁TFE (p =0.016), substantially underestimating T₁ at large T₁ values (> 1000 ms). In the in vivo study, the first mean myocardial T₁ values ± SD using MOLLI and IR-T₁TFE were 1306 ± 70 ms and 1484 ± 28 ms, respectively, and the second were 1297 ± 68 ms and 1474 ± 43 ms, respectively. The native myocardial T₁ obtained with MOLLI was lower than that of IR-T₁TFE (p < 0.001). The reproducibility of native myocardial T₁ mapping within the same sequence was not statistically significant (p = 0.11). This study demonstrates the utility and validity of myocardial T₁ mapping using IR-T₁TFE, which is a common sequence. This method was found to have high accuracy and reproducibility.