Feasibility study of a single breath-hold, 3D mDIXON pulse sequence for late gadolinium enhancement imaging of ischemic scar

Background: Late gadolinium enhancement (LGE) imaging is well validated for the diagnosis and quantification of myocardial infarction (MI). 2D LGE imaging involves multiple breath-holds for acquisition of short-axis slices to cover the left ventricle (LV). 3D LGE methods cover the LV in a single breath-hold; however, breath-hold duration is typically long with images susceptible to motion artifacts.

Purpose/Hypothesis: To assess a single breath-hold 3D mDIXON LGE pulse sequence for image quality and quantitation of MI.

Study Type: Prospective.

Population: Ninety- two patients with prior MI.

Field Strength/Sequence: 1.5T cardiac MRI protocol using both conventional 2D phase sensitive inversion recovery and 3D mDIXON LGE imaging 10 minutes following contrast administration in random order to avoid bias.

Assessment: Data were analyzed qualitatively for image quality (three observers). Quantitative assessment of myocardial scar mass (full-width half-maximum), scar transmurality, and contrast-to-noise ratio measurements were performed. Time for 2D and 3D LGE imaging was recorded.

Statistical Tests: Paired Student's t-test, Wilcoxon rank test, Cohen κ statistic, Pearson correlation, linear regression, and Bland–Altman analysis.

Results: Image quality scores were comparable between 3D and 2D LGE (1.4 ± 0.6 vs. 1.3 ± 0.5; P = 0.162). 3D LGE was associated with greater scar tissue mass (3D: 18.9 ± 17.5 g vs. 2D: 17.8 ± 16.2 g P = 0.03), although this difference was less pronounced when scar tissue was expressed as %LV mass (3D: 13.4 ± 9.9% vs. 2D: 12.7 ± 9.5% P = 0.07). For 3D vs. 2D scar mass there was a strong and significant positive correlation; Bland–Altman analysis showed mean mass bias of 1.1 g (95% confidence interval [CI]: –5.7 to 7.9). Segmental level agreement of scar transmurality between 3D and 2D LGE at the clinical viability threshold of 50% transmurality was excellent (κ = 0.870). 3D image acquisition (15.6 ± 1.4 sec) was just 5% of time required for 2D images (311.6 ± 43.2 sec) P < 0.0001.

Data Conclusion: Single breath-hold 3D mDIXON LGE imaging allows quantitative assessment of MI mass and transmurality, with comparable image quality, in vastly shorter overall acquisition time compared with standard 2D LGE imaging.