Abstract

Purpose: To develop a novel, free-breathing, 3D joint (Formula presented.) / (Formula presented.) / (Formula presented.) mapping sequence with Dixon encoding to provide co-registered 3D (Formula presented.), (Formula presented.), and (Formula presented.) maps and water-fat volumes with isotropic spatial resolution in a single (Formula presented.) min scan for comprehensive contrast-agent-free myocardial tissue characterization and simultaneous evaluation of the whole-heart anatomy. Methods: An interleaving sequence over 5 heartbeats is proposed to provide (Formula presented.), (Formula presented.), and (Formula presented.) encoding, with 3D data acquired with Dixon gradient-echo readout and 2D image navigators to enable (Formula presented.) respiratory scan efficiency. Images were reconstructed with a non-rigid motion-corrected, low-rank patch-based reconstruction, and maps were generated through dictionary matching. The proposed sequence was compared against conventional 2D techniques in phantoms, 10 healthy subjects, and 1 patient. Results: The proposed 3D (Formula presented.), (Formula presented.), and (Formula presented.) measurements showed excellent correlation with 2D reference measurements in phantoms. For healthy subjects, the mapping values of septal myocardial tissue were (Formula presented.), (Formula presented.), and (Formula presented.) for the proposed sequence, against (Formula presented.), (Formula presented.), and (Formula presented.) for 2D MOLLI, 2D (Formula presented.) -prep bSSFP and 2D (Formula presented.) -prep bSSFP, respectively. Promising results were obtained when comparing the proposed mapping to 2D references in 1 patient with active myocarditis. Conclusion: The proposed approach enables simultaneous 3D whole-heart joint (Formula presented.) / (Formula presented.) / (Formula presented.) mapping and water/fat imaging in (Formula presented.) 7 min scan time, demonstrating good agreement with conventional mapping techniques in phantoms and healthy subjects and promising results in 1 patient with suspected cardiovascular disease. © 2025 The Author(s). Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.