Post-processing techniques of 4D flow MRI: velocity and wall shear stress

by   Qi Gao, et al.

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).



page 17

page 18

page 21


Accurate quantification of blood flow wall shear stress using simulation-based imaging: a synthetic, comparative study

Simulation-based imaging (SBI) is a blood flow imaging technique that op...

Predicting the near-wall region of turbulence through convolutional neural networks

Modelling the near-wall region of wall-bounded turbulent flows is a wide...

Surface-sampled simulations of turbulent flow at high Reynolds number

A new approach to turbulence simulation, based on a combination of large...

Non-invasive hemodynamic analysis for aortic regurgitation using computational fluid dynamics and deep learning

Changes in cardiovascular hemodynamics are closely related to the develo...

Clipping over dissipation in turbulence models

Clipping refers to adding 1 line of code A=minA,B to force the variable ...

Proper tangential vector field for the wall shear stress evaluation in numerical blood flow simulations in human carotis tree

In numerical simulations of the cardiovascular system the realistic depi...

Numerical implementation of efficient grid-free integral wall models in unstructured-grid LES solvers

Two zonal wall-models based on integral form of the boundary layer diffe...
This week in AI

Get the week's most popular data science and artificial intelligence research sent straight to your inbox every Saturday.