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Non‐contrast myocardial infarct scar assessment using a hybrid native T 1 and magnetization transfer imaging sequence at 1.5T
Author(s) -
Duan Chong,
Zhu Yanjie,
Jang Jihye,
Rodriguez Jennifer,
Neisius Ulf,
Fahmy Ahmed S.,
Nezafat Reza
Publication year - 2019
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.27636
Subject(s) - magnetization transfer , contrast (vision) , gadolinium , myocardial infarction , nuclear magnetic resonance , magnetic resonance imaging , in vivo , nuclear medicine , medicine , steady state free precession imaging , materials science , biomedical engineering , physics , radiology , cardiology , optics , biology , microbiology and biotechnology , metallurgy
Purpose To develop a gadolinium‐free cardiac MR technique that simultaneously exploits native T 1 and magnetization transfer (MT) contrast for the imaging of myocardial infarction. Methods A novel hybrid T one and magnetization transfer (HYTOM) method was developed based on the modified look‐locker inversion recovery (MOLLI) sequence, with a train of MT‐prep pulses placed before the balanced SSFP (bSSFP) readout pulses. Numerical simulations, based on Bloch‐McConnell equations, were performed to investigate the effects of MT induced by (1) the bSSFP readout pulses, and (2) the MT‐prep pulses, on the measured, “apparent,” native T 1 values. The HYTOM method was then tested on 8 healthy adult subjects, 6 patients, and a swine with prior myocardial infarction (MI). The resulting imaging contrast between normal myocardium and infarcted tissues was compared with that of MOLLI. Late gadolinium enhancement (LGE) images were also obtained for infarct assessment in patients and swine. Results Numerical simulation and in vivo studies in healthy volunteers demonstrated that MT effects, resulting from on‐resonance bSSFP excitation pulses and off‐resonance MT‐prep pulses, reduce the measured T 1 in both MOLLI and HTYOM. In vivo studies in patients and swine showed that the HYTOM sequence can identify locations of MI, as seen on LGE. Furthermore, the HYTOM method yields higher myocardium‐to‐scar contrast than MOLLI (contrast‐to‐noise ratio: 7.33 ± 1.67 vs. 3.77 ± 0.66, P < 0.01). Conclusion The proposed HYTOM method simultaneously exploits native T 1 and MT contrast and significantly boosts the imaging contrast for myocardial infarction.