3D free-breathing water-specific abdominal T1 and T2 mapping using Cartesian sampling with spiral profile ordering (CASPR)

Motivation: Look-Locker-based methods have shown great efficiency for abdominal T1 mapping, but the combination with preparation-based 3D T2 mapping is challenging due to increasing scan times. Goal(s): To develop an efficient, motion-robust and confounder-corrected method for simultaneous abdominal water-specific T1 (wT1) and T2 (wT2) mapping. Approach: A T2-prepared inversion Look-Locker scheme was combined with a large-FOV Cartesian acquisition with spiral profile ordering. wT1 and wT2 maps were estimated using a soft-gated subspace reconstruction, dual-echo water-fat separation and B0-specific dictionary matching. Results: Phantom and in vivo experiments show good quantification at 3T and demonstrate the reproducibility and flexibility of the proposed method at different resolutions. Impact: Simultaneous water T1 and T2 mapping is achieved in a scan time of 5min at isotropic resolution of 3mm using a T2-prepared Look-Locker scheme with large-FOV CASPR sampling. This technique may be valuable in assessing diffuse and focal abdominal diseases.