Pontificia Universidad Católica de Chile Pontificia Universidad Católica de Chile
Sotelo J., Bächler P., Urbina J., Crelier G., Toro L., Ferreiro M., Valverde I., Andía M., Tejos C., Irarrázaval P. and Uribe S. (2017)

Quantification of pulmonary regurgitation in patients with repaired Tetralogy of Fallot by 2D phase-contrast MRI: Differences between the standard method of velocity averaging and a pixel-wise analysis

Revista : JRSM Cardiovascular Disease
Volumen : 6
Páginas : 1-8
Tipo de publicación : ISI Ir a publicación


Objectives: To compare the values of pulmonary regurgitation in patients with repaired Tetralogy of Fallot quantifiedfrom two-dimensional phase-contrast data, by using a new pixel-wise analysis and the standard velocity-averagingmethod.Design: Quantitative in silico and in vivo analysis.Setting: Hospital So´tero del Rı´o. The magnetic resonance images were acquired using a Philips Achieva 1.5T scanner.Participants: Twenty-five patients with repaired Tetralogy of Fallot who underwent cardiovascular magnetic resonanceimaging requested by their referring physicians were included in this study.Main outcome measures: Using a computational fluid dynamics simulation, we validated our pixel-wise method,quantifying the error of our method in comparison with the standard method. The patients underwent a standard twodimensionalphase-contrast magnetic resonance imaging acquisition for quantifying pulmonary artery flow. Pulmonaryregurgitation fraction was estimated by using our pixel-wise and the standard method. The two-dimensional flowprofiles were inspected looking for simultaneous antegrade and retrograde flows in the same cardiac phase.Statistical analysis was performed with t-test for related samples, Bland–Altman plots, and Pearson correlationcoefficient.Results: Estimation of pulmonary regurgitation fraction using the pixel-wise analysis revealed higher values comparedwith the standard method (39 16% vs. 30 22%, p-value <0.01). Eight patients (32%) had a difference of more than10% between methods. Analysis of two-dimensional flow profiles in these patients revealed simultaneous antegrade andretrograde flows through the pulmonary artery during systole–early diastole.Conclusion: Quantification of pulmonary regurgitation fraction in patients with repaired Tetralogy of Fallot through apixel-wise analysis yields higher values of pulmonary regurgitation compared with the standard velocity-averagingmethod.