3D Free-breathing T1, T2, T2* and PDFF mapping in the kidneys with Dictionary-Patch regularized Low Rank Motion Corrected Rosette MRF

Motivation: We aim to develop 3D multi-property mapping for quantitative tissue characterization of the kidneys, enabling objective evaluation of focal disease. Goal(s): To achieve whole-kidney coverage mapping of T1, T2, T2* and PDFF in a single free-breathing scan. Approach: 3D free-breathing stack-of-rosettes MRF data were acquired and reconstructed with Low Rank Motion Correction, regularized with a dictionary-patch based approach (LRMC-DP). Results: The proposed 3D free-breathing LRMC-DP MRF framework reduces respiratory motion artefacts, improving precision over conventional Low Rank MRF and producing similar T1/T2/T2*/PDFF maps to standard 2D breath-held MOLLI, T2prep-bSSFP and 6-echo GRE. In one patient, benign cysts were identified with the proposed LRMC-DP. Impact: 3D mapping of T1/T2/T2*/PDFF over the whole kidney is feasible with the proposed LRMC-DP in a single ~9 minute free-breathing scan. This method could enable objective characterization of focal diseases in the kidney, such as the classification of indeterminate masses.