Free‐running 3D whole‐heart T ₁ and T ₂ mapping and cine MRI using low‐rank reconstruction with non‐rigid cardiac motion correction

Purpose: To introduce non-rigid cardiac motion correction into a novel free-running framework for the simultaneous acquisition of 3D whole-heart myocardial T-1 and T-2 maps and cine images, enabling a similar to 3-min scan. Methods: Datawere acquired using a free-running 3D golden-angle radial readout interleaved with inversion recovery and T-2-preparation pulses. After correction for translational respiratorymotion, non-rigid cardiac-motion-corrected reconstruction with dictionary-based low-rank compression and patch-based regularization enabled 3D whole-heart T-1 and T-2 mapping at any given cardiac phase aswell aswhole-heart cardiac cine imaging. The frameworkwas validated and compared with established methods in 11 healthy subjects. Results: Good quality 3D T-1 and T-2 maps and cine images were reconstructed for all subjects. Septal T-1 values using the proposed approach (1200 +/- 50 ms) were higher than those from a 2D MOLLI sequence (1063 +/- 33 ms), which is known to underestimate T-1, while T-2 values from the proposed approach (51 +/- 4 ms) were in good agreement with those from a 2D GraSE sequence (51 +/- 2 ms). Conclusion: The proposed technique provides 3D T-1 and T-2 maps and cine images with isotropic spatial resolution in a single similar to 3.3-min scan.