Magnetization-Prepared Golden-angle RAdial Sparse Parallel (MP-GRASP) MRI for Rapid Free-Breathing 3D T1 Mapping of Renal Allografts

This work demonstrates rapid free-breathing 3D T1 mapping of the kidney using Magnetization-Prepared Golden-angle RAdial Sparse Parallel imaging (GraspT1). The accuracy and performance of GraspT1was prospectively compared with B1-corrected variable flip angle (VFA) T1 mapping in phantom and in 13 patients with renal transplant. In phantom, both GraspT1 and VFA enabled accurate T1 estimation compared to the gold standard. In patients, free-breathing 3D GraspT1 provided better spatial resolution for improved cortico-medullary differentiation compared to the VFA method, while achieving whole-kidney coverage and similar T1 quantification, at the expense of longer acquisition time.