Myocardialmapping at 5T using multi-inversion recovery real-time spoiled GRE.

To develop an accurate myocardialmapping technique at 5T using Look-Locker-based multiple inversion-recovery with the real-time spoiled gradient echo (GRE) acquisition.The proposedmapping technique (mIR-rt) samples the recovery of inverted magnetization using the real-time GRE and the images captured during diastole are selected forfitting. Multiple-inversion recoveries are employed to increase the sample size for accurate fitting. Themapping method was validated using Bloch simulation, phantom studies, and in 16 healthy volunteers at 5T.In both simulation and phantom studies, thevalues measured by mIR-rt closely approximate the referencevalues, with errors less than 3%, while the conventional MOLLI sequence underestimatesvalues. The myocardialvalues at 5T are 1553 ± 52 ms, 1531 ± 53 ms, and 1526 ± 60 ms (mean ± standard deviation) at the apex, middle, and base, respectively. Thevalues measured by MOLLI (1350 ± 48 ms, 1349 ± 47 ms, and 1354 ± 45 ms at the apex, middle, and base) were significantly lower than those of mIR-rt with< 0.001 for all three layers. The mIR-rt sequence method used in our study provides high reproducibility, particularly in the middle slices, supporting its practical relevance for myocardialmapping.The proposed method is feasible for myocardialmapping at 5T and provides better accuracy than the conventional MOLLI sequence.