Shortened Modified Look-Locker Inversion recovery (ShMOLLI) for clinical myocardial T1-mapping at 1.5 and 3 T within a 9 heartbeat breathhold

By S. Piechnik, V. Ferreira, E. Dall’Armellina, L. Cochlin, A. Greiser, S. Neubauer, M. Robson. Journal of Cardiovascular Magnetic Resonance, 2010

671 citations recorded by the source corpus.

BackgroundT1 mapping allows direct in-vivo quantitation of microscopic changes in the myocardium, providing new diagnostic insights into cardiac disease. Existing methods require long breath holds that are demanding for many cardiac patients. In this work we propose and validate a novel, clinically applicable, pulse sequence for myocardial T1-mapping that is compatible with typical limits for end-expiration breath-holding in patients.Materials and methodsThe Shortened MOdified Look-Locker Inversion recovery (ShMOLLI) method uses sequential inversion recovery measurements within a single short breath-hold. Full recovery of the longitudinal magnetisation between sequential inversion pulses is not achieved, but conditional interpretation of samples for reconstruction of T1-maps is used to yield accurate measurements, and this algorithm is implemented directly on the scanner. We performed computer simulations for 100 ms<T1 < 2.7 s and heart rates 40-100 bpm followed by phantom validation at 1.5T and 3T. In-vivo myocardial T1-mapping using this method and the previous gold-standard (MOLLI) was performed in 10 healthy volunteers at 1.5T and 3T, 4 volunteers with contrast injection at 1.5T, and 4 patients with recent myocardial infarction (MI) at 3T.ResultsWe found good agreement between the average ShMOLLI and MOLLI estimates for T1 < 1200 ms. In contrast to the original method, ShMOLLI showed no dependence on heart rates for long T1 values, with estimates characterized by a constant 4% underestimation for T1 = 800-2700 ms. In-vivo, ShMOLLI measurements required 9.0 ± 1.1 s (MOLLI = 17.6 ± 2.9 s). Average healthy myocardial T1 s by ShMOLLI at 1.5T were 966 ± 48 ms (mean ± SD) and 1166 ± 60 ms at 3T. In MI patients, the T1 in unaffected myocardium (1216 ± 42 ms) was similar to controls at 3T. Ischemically injured myocardium showed increased T1 = 1432 ± 33 ms (p < 0.001). The difference between MI and remote myocardium was estimated 15% larger by ShMOLLI than MOLLI (p < 0.04) which suffers from heart rate dependencies for long T1. The in-vivo variability within ShMOLLI T1-maps was only 14% (1.5T) or 18% (3T) higher than the MOLLI maps, but the MOLLI acquisitions were twice longer than ShMOLLI acquisitions.ConclusionShMOLLI is an efficient method that generates immediate, high-resolution myocardial T1-maps in a short breath-hold with high precision. This technique provides a valuable clinically applicable tool for myocardial tissue characterisation.

Subfields: Cardiology and Cardiovascular Medicine, Radiology, Nuclear Medicine and Imaging

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Citations in the corpus

T1-mapping in the heart: accuracy and precision (2014, methodology): “Loss of resolution due to cardiac motion maps acquired using MOLLI 5s(3s)3s, ShMOLLI, and SASHA eart is apparent due to variation in SNR from surface coil sensitivity ximate nature of the Look-Locker correction and due to magnetization stimation; 3-parameter fitting is more accurate but has signific”
What are normal relaxation times of tissues at 3 T? (2017, methodology): “[29] developed a Shortened Modified Look–Locker Inversion Recovery (ShMoLLI) method to compute the T1 values of the myocardium within a 9-heartbeat breath-hold.”
Clinical recommendations for cardiovascular magnetic resonance mapping of T1, T2, T2* and extracellular volume: A consensus statement by the Society for Cardiovascular Magnetic Resonance (SCMR) endorsed by the European Association for Cardiovascular Imaging (EACVI) (2017, background): “Piechnik SK, Ferreira VM, Lewandowski AJ, Ntusi N. a B, Banerjee R, Holloway C, et al. Normal variation of magnetic resonance T1 relaxation times in the human population at 1.5 T using ShMOLLI.”
Myocardial T1 mapping and extracellular volume quantification: a Society for Cardiovascular Magnetic Resonance (SCMR) and CMR Working Group of the European Society of Cardiology consensus statement (2013, background): “that are available to users as research “sequences” [7,51,56,80,82-85].”
Noncontrast T1 mapping for the diagnosis of cardiac amyloidosis. (2013, methodology): “For T1 mapping, a midventricular short-axis and a 4-chamber long-axis plane were acquired using the shortened modified look-locker inversion recovery (ShMOLLI) sequence, as previously described (16).”
Cardiac T1 Mapping and Extracellular Volume (ECV) in clinical practice: a comprehensive review (2016, methodology): “The Shortened MOLLI (ShMOLLI) scheme uses sequential inversion-recovery measurements with a single breath hold of only nine successive heart beats [7] and a conditional fitting algorithm to account for the short recovery period between inversion pulses.”