Comparison of patient-specific inlet boundary conditions in the numerical modelling of blood flow in abdominal aortic aneurysm disease
Comparison of patient-specific inlet boundary conditions in the numerical modelling of blood flow in abdominal aortic aneurysm disease
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DOI：
10.1002/cnm.2535
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发表时间：
2013-02-01
影响因子：
2.1
通讯作者：
Hoskins, Peter R.
中科院分区：
文献类型：
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作者：
Hardman, David;Semple, Scott I.;Hoskins, Peter R.
从相衬MRI中获得三个入口边界条件数据集：(i)中心线速度数据使用Womersley方程（Womersley）转换为二维（2D）速度剖面，（ii）具有一个轴向速度分量的二维速度剖面（1CV）， （iii）具有三个速度分量的二维速度剖面（3CV）。计算流体动力学使用刚性壁方法和从计算机断层扫描数据集中提取的几何数据进行。螺旋流在1CV和3CV模拟中都存在，3CV情况下的螺旋流模式更为复杂。沃默斯利方法在没有螺旋流的情况下产生了简化的流动模式。定量指标（螺旋流动指数、平均壁面剪应力、振荡指数）的平均值与3CV进气道数据进行了比较。Womersley进气道数据（28%,71%,56%）和1CV进气道数据（9%,24%,69%）的这些数据都较低。结论：基于中心线速度的进气口方法，如多普勒超声可获得的进气口方法，可显著简化腹主动脉瘤血流动力学，因此不推荐使用。当需要一般流动特征和空间壁面剪切应力时，MRI的单速度分量（轴向）数据可能就足够了。理想情况下，二维MRI速度剖面与3速度分量数据是首选，以充分说明螺旋流。版权所有：John Wiley & Sons， Ltd。
Three inlet boundary condition datasets were derived from phase-contrast MRI: (i) centre line velocity data converted to two-dimensional (2D) velocity profile using Womersley equations (Womersley), (ii) 2D velocity profile with one axial component of velocity (1CV), (iii) 2D velocity profile with three components of velocity (3CV). Computational fluid dynamics was performed using a rigid wall approach with geometry data extracted from the computed tomography dataset. Helical flow was present in the 1CV and 3CV simulations, with more complex patterns for the 3CV case. The Womersley method produced simplified flow patterns with an absence of helical flow. Mean values of quantitative indices (helical flow index, mean wall shear stress, oscillatory index) were compared with the 3CV inlet data. These were lower for both the Womersley inlet data (28%, 71%, 56%) and the 1CV inlet data (9%, 24%, 69%). It was concluded that inlet methods based on centre line velocity, such as might be obtained from Doppler ultrasound, lead to significantly simplified abdominal aortic aneurysm haemodynamics and thus are not recommended. Single velocity component (axial) data from MRI might suffice when general flow characteristics and spatial wall shear stress are required. Ideally 2D MRI velocity profiles with 3-velocity component data are preferred to fully account for helical flow. Copyright (c) 2012 John Wiley & Sons, Ltd.