Key result
The improved divergence-free smoothing method greatly reduced divergence error and allowed for more accurate calculation of aortic wall shear stress from 4D flow MRI compared to computational fluid dynamics.
Why the study?
Traditional divergence-free smoothing for 4D flow MRI cannot handle flow in the vessel near-wall region or satisfy no-slip boundary conditions, and coarse resolution underestimates near-wall velocity gradients.
Does an improved divergence-free smoothing method improve the accuracy of velocity and wall shear stress calculations in 4D flow MRI compared to traditional methods?
Does an improved divergence-free smoothing method improve the accuracy of velocity and wall shear stress calculations in 4D flow MRI compared to traditional methods?
An improved divergence-free smoothing method for 4D flow MRI significantly reduces divergence errors and improves the accuracy of wall shear stress calculations compared to traditional methods.
May support refined aortic hemodynamics research with 4D flow MRI; leaves open clinical validation.
As the original velocity field obtained from four-dimensional (4D) flow magnetic resonance imaging (MRI) contains considerable amount of noises and errors, the available Divergence-free smoothing (DFS) method can be used to process the 4D flow MRI data for reducing noises, eliminating errors, fixing missing data and eventually providing the smoothed flow field. However, the traditional DFS does not have the ability to deal with the flow in the near wall region of vessel, especially for satisfying the no-slip boundary condition. In this study, therefore, an improved DFS method with specific near wall treatment is introduced for processing with 4D flow MRI inner flow with curved wall boundary as the blood flows. On the other hand, due to the coarse resolution of 4D flow MRI, velocity gradients in the near wall region are normally underestimated. As a result, a special wall function is required for accurately computing wall shear stress (WSS).
No takes yet. Share an insight, caveat, or question.
Gao et al. (2019) studied Ascending aortic aneurysm with aortic regurgitation (n=1). Improved Divergence-Free Smoothing (DFS) method vs. Traditional DFS / Computational Fluid Dynamics (CFD) was evaluated on Divergence error reduction and Wall Shear Stress (WSS) calculation accuracy. The improved divergence-free smoothing method greatly reduced divergence error and allowed for more accurate calculation of aortic wall shear stress from 4D flow MRI compared to computational fluid dynamics.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: