Abstract

Purpose: To develop a 3D free-breathing cardiac multi-parametric mapping framework that is robust to confounders of respiratory motion, fat, and B1+ inhomogeneities and validate it for joint myocardial T1 and T1? mapping at 3T. Methods: An electrocardiogram-triggered sequence with dual-echo Dixon readout was developed, where nine cardiac cycles were repeatedly acquired with inversion recovery and T1? preparation pulses for T1 and T1? sensitization. A subject-specific respiratory motion model relating the 1D diaphragmatic navigator to the respiration-induced 3D translational motion of the heart was constructed followed by respiratory motion binning and intra-bin 3D translational and inter-bin non-rigid motion correction. Spin history B1+ inhomogeneities were corrected with optimized dual flip angle strategy. After water-fat separation, the water images were matched to the simulated dictionary for T1 and T1? quantification. Phantoms and 10 heathy subjects were imaged to validate the proposed technique. Results: The proposed technique achieved strong correlation (T1: R2 = 0.99; T1?: R2 = 0.98) with the reference measurements in phantoms. 3D cardiac T1 and T1? maps with spatial resolution of 2 × 2 × 4 mm were obtained with scan time of 5.4 ± 0.5 min, demonstrating comparable T1 (1236 ± 59 ms) and T1? (50.2 ± 2.4 ms) measurements to 2D separate breath-hold mapping techniques. The estimated B1+ maps showed spatial variations across the left ventricle with the septal and inferior regions being 10%–25% lower than the anterior and septal regions. Conclusion: The proposed technique achieved efficient 3D joint myocardial T1 and T1? mapping at 3T with respiratory motion correction, spin history B1+ correction and water-fat separation. © 2024 International Society for Magnetic Resonance in Medicine.