Department of Mechanical, Materials and Aerospace Engineering, Illinois Institute of Technology, 10 W 32nd St, Chicago, IL 60616, USA.
Ann Biomed Eng. 2012 Apr;40(4):860-70. doi: 10.1007/s10439-011-0447-6. Epub 2011 Oct 21.
This paper compares numerical predictions of turbulence intensity with in vivo measurement. Magnetic resonance imaging (MRI) was carried out on a 60-year-old female with a restenosed aortic coarctation. Time-resolved three-directional phase-contrast (PC) MRI data was acquired to enable turbulence intensity estimation. A contrast-enhanced MR angiography (MRA) and a time-resolved 2D PCMRI measurement were also performed to acquire data needed to perform subsequent image-based computational fluid dynamics (CFD) modeling. A 3D model of the aortic coarctation and surrounding vasculature was constructed from the MRA data, and physiologic boundary conditions were modeled to match 2D PCMRI and pressure pulse measurements. Blood flow velocity data was subsequently obtained by numerical simulation. Turbulent kinetic energy (TKE) was computed from the resulting CFD data. Results indicate relative agreement (error ≈10%) between the in vivo measurements and the CFD predictions of TKE. The discrepancies in modeled vs. measured TKE values were within expectations due to modeling and measurement errors.
本文比较了湍流强度的数值预测与体内测量。对一位患有再狭窄主动脉缩窄的 60 岁女性进行了磁共振成像 (MRI)。采集时相对比 (PC) MRI 数据以实现湍流强度估计。还进行了对比增强磁共振血管造影 (MRA) 和时相对比 2D PCMRI 测量，以获取进行后续基于图像的计算流体动力学 (CFD) 建模所需的数据。从 MRA 数据构建了主动脉缩窄和周围血管的 3D 模型，并对生理边界条件进行建模以匹配 2D PCMRI 和压力脉冲测量。随后通过数值模拟获得血流速度数据。从所得 CFD 数据计算出湍流动能 (TKE)。结果表明，体内测量值与 TKE 的 CFD 预测值之间存在相对一致性（误差≈10%）。由于建模和测量误差，模型与测量 TKE 值之间的差异在预期范围内。
