Free-breathing three-dimensional high-resolution Dixon late gadolinium enhancement imaging for chronic myocardial infarction assessment at 3T.

BACKGROUND: Late gadolinium enhancement (LGE) imaging is considered the imaging reference standard for the diagnosis of myocardial infarction and scarring. The aim of this study is to evaluate a free-breathing high-resolution three-dimensional (3D) Dixon LGE imaging prototype with image navigation (iNAV) in chronic myocardial infarction on a 3T system.

METHODS: Consecutive myocardial infarction patients were enrolled to undergo CMR examination between February 2024 and January 2025. LGE protocols included breath-hold two-dimensional (2D) phase-sensitive inversion recovery (PSIR) and free-breathing iNAV 3D Dixon acquisitions. Radiologist image quality scoring, contrast ratio (CR), quantitative LGE assessment, and scan time were obtained and reported. Paired t-tests, Wilcoxon signed-rank tests, and repeated-measures ANOVA were used for the comparison.

RESULTS: A total of 32 participants (50 years ± 11; 31 male, 1 female) were included. 3D LGE reduced scan time by 2m9s (3D: 4m34s [3m50s, 5m17s], 2D: 6m43s [5m17s, 7m41s], P<0.001). Overall image quality showed no difference (3D: 4 [3, 4], 2D: 4 [3, 5], P = 0.474). 3D LGE showed a trend toward higher image quality scores (3D: 4 [3, 4], 2D: 3 [2, 4], P = 0.053) in patients with respiratory motion artifacts on 2D images. LGE-to-blood CR was significantly higher in the 3D LGE than the 2D LGE images (P<0.001). LGE mass (P = 0.11) and LGE extent (P = 0.02) showed no significant difference between the 3D and 2D LGE datasets.

CONCLUSION: Free-breathing iNAV 3D Dixon LGE is feasible at 3T, achieving comparable image quality and scar quantification to 2D PSIR within shorter scan times. It improves CR and enables simultaneous assessment of myocardial fibrosis and fat infiltration.