Validation of numerical simulation methods in aortic arch using 4D Flow MRI.
Validation of numerical simulation methods in aortic arch using 4D Flow MRI.
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DOI：
10.1007/s00380-017-0979-2
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发表时间：
2017-08
影响因子：
1.5
通讯作者：
Yasukochi S
中科院分区：
文献类型：
--
作者：
Miyazaki S;Itatani K;Furusawa T;Nishino T;Sugiyama M;Takehara Y;Yasukochi S
计算流体动力学(CFD)是研究血流动力学的金标准。然而，CFD结果取决于边界条件和计算模型。本研究的目的是通过与四维(4D)血流磁共振成像(MRI)获得的血流向量的实际测量进行比较来验证CFD方法。对1例健康成人和1例儿童双主动脉弓患者行4D Flow MRI检查。主动脉腔被分割，以显示血流情况。基于三种湍流模型：层流、大涡模拟(LES)和重整化群k-ε模型(RNG k-ε)，对相同的几何形状进行了CFD分析。比较MRI和CFD结果的血流速度矢量分量，即壁面切应力(WSS)和血流能量损失(EL)。MRI结果在小血管中的流速被低估了，包括颈部血管。MRI观察到左心室扭转引起的升主动脉内螺旋血流。CFD和MRI均能很好地显示主动脉弓远端的二次血流。RNGk-ε模型的儿童MRI和CFD速度向量分量的平均相关系数最高(升主动脉0.530，主动脉弓0.768，降主动脉0.584)。MRI的WSS和EL值不到CFD的一半，但WSS的分布规律非常相似。由于涡动粘性，RNG、k-ε和LES的WSS和EL估计值均高于层流模式。CFD计算实现了主动脉弓远端的精确流动，并与4D Flow MRI的实际测量结果进行了比较，较好地模拟了WSS分布。然而，升主动脉内的螺旋流动没有得到模拟。湍流模型提高了计算精度，其中RNGk-ε模型与4D flow MRI的相关性最高。
Computational fluid dynamics (CFD) are the gold standard in studying blood flow dynamics. However, CFD results are dependent on the boundary conditions and the computation model. The purpose of this study was to validate CFD methods using comparison with actual measurements of the blood flow vector obtained with four-dimensional (4D) flow magnetic resonance imaging (MRI). 4D Flow MRI was performed on a healthy adult and a child with double-aortic arch. The aortic lumen was segmented to visualize the blood flow. The CFD analyses were performed for the same geometries based on three turbulent models: laminar, large eddy simulation (LES), and the renormalization group k–ε model (RNG k–ε). The flow-velocity vector components, namely the wall shear stress (WSS) and flow energy loss (EL), of the MRI and CFD results were compared. The flow rate of the MRI results was underestimated in small vessels, including the neck vessels. Spiral flow in the ascending aorta caused by the left ventricular twist was observed by MRI. Secondary flow distal to the aortic arch was well realized in both CFD and MRI. The average correlation coefficients of the velocity vector components of MRI and CFD for the child were the highest for the RNG k–ε model (0.530 in ascending aorta, 0.768 in the aortic arch, 0.584 in the descending aorta). The WSS and EL values of MRI were less than half of those of CFD, but the WSS distribution patterns were quite similar. The WSS and EL estimates were higher in RNG k–ε and LES than in the laminar model because of eddy viscosity. The CFD computation realized accurate flow distal to the aortic arch, and the WSS distribution was well simulated compared to actual measurement using 4D Flow MRI. However, the helical flow was not simulated in the ascending aorta. The accuracy was enhanced by using the turbulence model, and the RNG k–ε model showed the highest correlation with 4D Flow MRI.
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DOI：
10.1007/s10558-009-9074-3
发表时间：
2009-06-01
期刊：
CARDIOVASCULAR ENGINEERING
影响因子：
--
作者：
Zhang, Hongjun;Li, John K-J.
通讯作者：
Li, John K-J.
影响因子：
37.8
作者：
KILNER, PJ;YANG, GZ;LONGMORE, DB
通讯作者：
LONGMORE, DB
DOI：
10.1115/1.4023132
发表时间：
2013-01-01
影响因子：
1.7
作者：
Kousera, C. A.;Wood, N. B.;Xu, X. Y.
通讯作者：
Xu, X. Y.
影响因子：
3.3
作者：
Casas, Belen;Lantz, Jonas;Ebbers, Tino
通讯作者：
Ebbers, Tino
影响因子：
1.1
作者：
Antiga, Luca;Steinman, David A.
通讯作者：
Steinman, David A.