Abstract
BACKGROUND: Cardiovascular magnetic resonance (CMR) imaging relies on T(2) mapping to assess myocardial tissue properties. However, T(2) maps are subject to motion artifacts and signal interference, prompting exploration of techniques such as gradient-spin-echo (GraSE) sequences, heart phase acquisition, and dark blood (DB) imaging to improve image quality and reliability. PURPOSE: This prospective study evaluates the T(2) relaxation time (T(2)) variability and the image quality of T(2) maps obtained in end-systole and end-diastole with and without fat saturation (FS), using GraSE sequence in CMR imaging. Furthermore, improved motion-sensitized driven-equilibrium (iMSDE) was compared with double inversion recovery (DIR) as an alternative DB technique. MATERIALS AND METHODS: Five variants of the DB GraSE sequence were developed and performed on a 1.5 Tesla MRI scanner. Forty-four healthy volunteers prospectively underwent the following sequences: GraSE in end-diastole (GraSE-ED), GraSE-ED with FS (GraSE-ED-FS), GraSE in end-systole (GraSE-ES), GraSE-ES with FS (GraSE-ES-FS), and commercial GraSE-ED (GraSE-CO). Four GraSE variants utilized iMSDE technique, while GraSE-CO used DIR for blood suppression. T(2), image quality, and visual artifacts were measured. RESULTS: Ten volunteers were excluded due to image artifacts or missing datasets. Among the remaining 34 participants, the mean global T(2) was measured. No significant differences were seen among all variants (P > .05 for all comparisons). Intra- and inter-reader agreement of global T(2) values for all GraSE sequence were very good (r > 0.8 for both). Image quality was rated moderate or good for all variants of GraSE sequences. A lower incidence of artifacts was observed in end-systolic compared to end-diastolic imaging. CONCLUSION: All variants of GraSE sequence are highly reproducible and myocardial T(2) values did not significantly differ with heart phase. iMSDE is feasible as an alternative DB technique for T(2) mapping enabling acquisition in systole, which shows a lower incidence of artifacts compared to diastole.