3D myocardial T1 mapping at 3T using variable flip angle method: pilot study

Abstract

Purpose: Myocardial T1 mapping is an emerging technique that could improve cardiovascular magnetic resonance diagnostic accuracy. In this study, a variable flip angle approach with B1 correction is proposed at 3T on the myocardium, employing standard 3D spoiled fast gradient echo and echo planar imaging sequences.

Methods: The method was tested on phantoms to determine the set of standard 3D spoiled fast gradient echo angles adapted to myocardial T1 measurements and was compared to the inversion-recovery spin-echo reference T1 method. Seven volunteers underwent magnetic imaging resonance to acquire myocardial T1 maps and T1 values of the human heart.

Results: This original method demonstrated good reproducibility in phantoms and a significant correlation between variable flip angle T1 values and reference inversion-recovery spin-echo T1 values. It yielded myocardial T1 values consistent with expected T1 and an increasing homogenization of myocardial segments owing to B1 correction. The mean myocardial T1 value was 1341 ± 42 ms.

Conclusion: Myocardial 3D T1 mapping using the variable flip angle approach can potentially be useful for evaluating fibrosis on the entire myocardium using a standard clinical sequence.