Myocardial T1 and T2 Mapping at 5.0 T: Feasibility and Comparison with 3.0-T MRI

BackgroundMyocardial T1 and T2 mapping provide a non-invasive quantitative assessment of cardiac tissue. While established at 1.5-T and 3.0-T MRI, the mapping performance and reference values at 5.0-T MRI remain to be investigated. This study aims to evaluate the feasibility and establish reference values for cardiac T1 and T2 mapping at 5.0-T MRI in healthy subjects. MethodsIn this prospective study, 50 healthy volunteers underwent cardiac MRI at both 3.0-T and 5.0-T MRI systems from February to April 2025. Mapping protocols included MOdified Look Locker Inversion recovery (MOLLI, T1), T2-prepared gradient-echo (T2-prep-GRE, T2), and a simultaneous multi-parametric mapping technique (Multimap, T1 and T2). At 3.0-T MRI, both balanced steady-state free precession (bSSFP) and fast low-angle shot (FLASH) readouts were employed, while only the FLASH readout was used at 5.0-T MRI. Intra-observer, inter-observer, and scan-rescan reproducibility were assessed. Statistical analyses included coefficient of variation (CoV), intraclass correlation coefficient (ICC), and Bland-Altman analysis. ResultsAll techniques at 5.0-T MRI yielded high-quality, artifact-free images. Native T1 values were significantly higher at 5.0 T than at 3.0-T MRI (MOLLI: 1452.9 {+/-} 33.2 ms vs. 1305.9 {+/-} 38.3 ms, P < 0.0001), while T2 values were significantly lower (T2-prep-GRE: 37.53 {+/-} 1.74 ms vs. 43.97 {+/-} 2.95 ms, P < 0.0001). Scan-rescan reproducibility at 5.0 T (ICC: 0.87-0.92; CoV: 2.41%-3.25%) was comparable to 3.0-T MRI. The measurement precision of 5.0 T was higher than 3.0-T MRI with FLASH readout and slightly inferior to bSSFP-based techniques. Multimap achieved efficient, simultaneous T1 and T2 quantification with acceptable reproducibility at 5.0-T MRI. ConclusionMyocardial T1 and T2 mapping at 5.0-T MRI are reliable and reproducible in healthy individuals, offering reference values for normal myocardium at this field strength. The good measurement reproducibility and precision of 5.0-T cardiac mapping support its clinical potential for myocardial tissue characterization.