In participants who underwent 3-T cardiac MRI with both MOLLI and ShMOLLI sequences, native T1 was higher with MOLLI than ShMOLLI, but ECV was consistent across sequences.
Reference native T1 values in healthy volunteers differed between MOLLI and ShMOLLI sequences at 3 T.
MOLLI yielded systematically higher native T1 values than ShMOLLI across all cardiovascular conditions and healthy volunteers.
ECV values were consistent between MOLLI and ShMOLLI for most disease groups.
Native T1 measurements showed strong intersequence correlation between MOLLI and ShMOLLI.
After standardization to sequence-specific baselines, pathologic deviations from normal were comparable between MOLLI and ShMOLLI.
Women showed higher native T1 values than men in healthy volunteers for both sequences.
A supplementary swine study supported the technical validity of both MOLLI and ShMOLLI sequences.
The study enrolled 1237 clinical participants spanning healthy volunteers and 13 cardiovascular pathology groups.
This research examined two commonly used heart MRI techniques — MOLLI and ShMOLLI — that measure a property of heart muscle tissue called T1 relaxation time, which can help detect various heart diseases. The study scanned 1,237 participants at 3 Tesla MRI strength, including healthy volunteers and people with 13 different heart conditions. It found that MOLLI consistently measured T1 values about 46 milliseconds higher than ShMOLLI across all groups, meaning the two techniques cannot be directly compared without accounting for this systematic difference. However, a related measurement called extracellular volume fraction (ECV), which reflects the amount of scar or fibrosis in heart tissue, was nearly identical between the two techniques for most conditions. This research suggests that when comparing T1 measurements between different hospitals or studies, it is critical to know which technique was used, since MOLLI and ShMOLLI give different absolute numbers even when measuring the same hearts. Despite this difference in raw T1 values, the ability of both techniques to distinguish diseased hearts from healthy ones was similar when measurements were compared against their own normal reference values. The study also found that women naturally have higher T1 values than men, highlighting the importance of using sex-specific reference ranges. Practically, this work provides a large set of reference values for both MOLLI and ShMOLLI at 3 Tesla MRI in a Chinese population across many heart conditions, filling an important gap since most prior reference data came from Western populations and often used only one technique. The findings support using ECV as a more sequence-independent measure and suggest that with proper baseline standardization, results from MOLLI and ShMOLLI can be meaningfully compared across clinical settings.
Zhang H, Cui C, Zhou W, Zheng T, Yang W, Zhou D, et al.. (2026). Myocardial T1 Mapping at 3 T: A Comparison of MOLLI and ShMOLLI across Healthy Volunteers and Various Cardiovascular Pathologies.. Radiology. https://doi.org/10.1148/radiol.252886