Fast cardiac T_1ρ,adiab mapping using slice-selective adiabatic spin-lock preparation pulses

Area of Science:

• Cardiovascular Magnetic Resonance Imaging
• Quantitative MRI Techniques

Background:

• Myocardial T1ρ mapping traditionally requires multiple images per slice within a single breathhold.
• Non-selective adiabatic pulses offer robust spin-lock preparation for T1ρ,adiab mapping.

Purpose of the Study:

• To develop and evaluate a rapid, multi-slice approach for myocardial T1ρ,adiab mapping.
• To accelerate whole-heart 2D T1ρ,adiab imaging using interleaved slice acquisition.

Main Methods:

• Implemented a novel sequence with slice-selective T1ρ,adiab preparation for acquiring multiple interleaved slices per breathhold.
• Quantitatively assessed the sequence in phantom experiments and 10 healthy volunteers.
• Demonstrated the sequence in two patients with myocardial scar.

Main Results:

• Phantom experiments showed minimal slice-to-slice variation (1.62% ± 1.05%) and high precision (4.51 ± 0.68 ms).
• The proposed sequence yielded lower mean relaxation times (137.7 ± 5.3 ms) and better spatial standard deviation (18.7 ± 1.8 ms) in volunteers compared to single-slice.
• Within-subject coefficient of variation was comparable (5.93% ± 1.57% vs. 6.31% ± 1.92%), with no significant slice variation effect.

Conclusions:

• The proposed multi-slice sequence achieves a twofold acceleration in myocardial T1ρ,adiab mapping.
• It demonstrates comparable within-subject variability to conventional 2D sequences.
• The technique offers significantly improved precision for cardiac T1ρ,adiab measurements.