2D cine vs. 3D free-breathing self-navigated whole heart for aortic root measurements in congenital heart disease

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac magnetic resonance is considered the method choice for determination aortic root diameters in congenital heart disease. Usually, a cross-sectional 2D cine stack acquired perpendicular to vessel’s axis. However, this requires considerable patient collaboration and precise planning image planes. This study compares recently introduced free-breathing high-resolution 3D self-navigating whole sequence (3D self nav) technique diameters. Methods Two observers measured on nav planes (figure A B), 1.5T scanner, cusp-commissure (CuCo) cusp-cusp (CuCu) enddiastolic B C). Asymmetry was evaluated by ratio minimal maximum CuCu diameter. were compared transthoracic echocardiographic (TTE) Results 65 exams 58 patients (mean age 32 ± 15y) included. spatial resolution 1.4x4.5-6mm 1.1³mm, respectively. yielded larger than CuCo, respectively (table). Intra- interobserver variabilities excellent both techniques ( bias -0.5 1.0 mm). Intra-observer variability experienced observer better (F-test p < 0.05). Aortic asymmetry more pronounced with bicuspid valve (BAV: 0.73 (0.69; 0.78) vs. 0.93 (0.9; 0.96), 0.001), which associated difference TTE diameters: 5.5 3.3 3.8 mm, = 0.03. Conclusion Both, allow reliable measurement should be privileged avoid underestimation diameter, particularly asymmetric roots and/or BAV CuCo min mid max Mean diameter (mm) 33.5 34.8 36.2 33.4 37.6 38.5 34.5 35.9 37.2 34.3 39.7 -1.0 -1.1 -0.8 -1.3 -1.2 95% Limits agreement -5.1 3.2 -5.3 3.1 -5.5 3.5 -4.7 2.0 2.3 Standard deviation 2.1 2.4 1.7 1.8 Variance (mm2) 4.5 5.2 5.6 2.9 Pearson’s correlation (r) 0.952 0.954 0.945 0.944 0.972 0.951 P value (t-test) 0.003 0.001 0.006 0.005 <0.001 Figure.