On the Use of In Vivo Measured Flow Rates as Boundary Conditions for Image-Based Hemodynamic Models of the Human Aorta: Implications for Indicators of Abnormal Flow
On the Use of In Vivo Measured Flow Rates as Boundary Conditions for Image-Based Hemodynamic Models of the Human Aorta: Implications for Indicators of Abnormal Flow
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DOI：
10.1007/s10439-011-0431-1
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发表时间：
2012-03-01
影响因子：
3.8
通讯作者：
Morbiducci, U.
中科院分区：
文献类型：
--
作者：
Gallo, D.;De Santis, G.;Morbiducci, U.
这项研究的目的是调查施加个性化的、非侵入性测量的血流速度作为边界条件(BCS)如何影响基于图像的人体主动脉血流动力学计算研究。我们从一名健康人的4D相位对比MRI采集中提取(1)具有主动脉上动脉的胸主动脉的几何形状和(2)所有边界的流速波形。进行了流动模拟，分析了基于实测流量的不同BC方案对基于壁面剪应力(WSS)的异常流动指标的影响。我们的结果表明，所采用的BC策略对主动脉多个出口之间的流量重分配以及基于WSS的指标的分布和大小都有很大的影响。以采用BC方案的血流动力学模型为参考，当采用其他BC方案时，基于WSS的指标差异高达49%，其中BC方案的计算值与实测值之间的一致性较好。总之，我们证明，在特定于受试者的人体主动脉计算血流动力学模型中，基于非侵入性测量的流速波形施加BC设置在很大程度上影响异常血流的指标。因此，当规定了流量等BCS时，必须应用BCS设置，以确保真实的、特定于对象的瞬时流量分布。
The purpose of this study is to investigate how the imposition of personalized, non-invasively measured blood flow rates as boundary conditions (BCs) influences image-based computational hemodynamic studies in the human aorta. We extracted from 4D phase-contrast MRI acquisitions of a healthy human (1) the geometry of the thoracic aorta with supra-aortic arteries and (2) flow rate waveforms at all boundaries. Flow simulations were carried out, and the implications that the imposition of different BC schemes based on the measured flow rates have on wall shear stress (WSS)-based indicators of abnormal flow were analyzed. Our results show that both the flow rate repartition among the multiple outlets of the aorta and the distribution and magnitude of the WSS-based indicators are strongly influenced by the adopted BC strategy. Keeping as reference hemodynamic model the one where the applied BC scheme allowed to obtain a satisfactory agreement between the computed and the measured flow rate waveforms, differences in WSS-based indicators up to 49% were observed when the other BC strategies were applied. In conclusion, we demonstrate that in subject-specific computational hemodynamics models of the human aorta the imposition of BC settings based on non-invasively measured flow rate waveforms influences indicators of abnormal flow to a large extent. Hence, a BCs set-up assuring realistic, subject-specific instantaneous flow rate distribution must be applied when BCs such as flow rates are prescribed.