Liu Siyu, Wang Sai, Tian Hongan, Xue Junzhen, Guo Yuxin, Yang Jingxi, Jiang Haobin, Yang Jian Bao, Zhang Yang
School of Public Health and Nursing, Xianning Medical College, Hubei University of Science and Technology, Xianning, China.
The First Affiliated Hospital of Hubei University of Science and Technology, Xianning, China.
PeerJ. 2025 Apr 28;13:e19336. doi: 10.7717/peerj.19336. eCollection 2025.
Carotid atherosclerotic vascular disease significantly contributes to strokes, presenting a heightened risk of early recurrent ischemia. Computational fluid dynamics (CFD) has shown potential in predicting subsequent stroke recurrence in patients with carotid stenosis.
This study aims to investigate the differences in computational time and accuracy of four key hemodynamic indices-wall shear stress (WSS), time-averaged wall shear stress (TAWSS), Oscillatory Shear Index (OSI), and relative residence time (RRT)-across different viscosity models, thereby providing optimal model selection for clinical cases and offering guidance for clinicians' decision-making.
A three-dimensional vessel model was established using computed tomography angiography (CTA), followed by CFD simulations to calculate WSS, TAWSS, OSI, and RRT. The accuracy of the simulations was validated by comparing the results with those from Razavi et al. (10.1016/j.jbiomech.2011.04.023). Numerical errors in different parameters under varying stenosis levels and viscosity models were analyzed.
In the transient state, when degree of stenosis is 38%, 72%-84%, the performance difference between the two is less than 6%. For TAWSS, the difference is 0% when degree of stenosis is 12%, 18%, 26%, 54%, and 76%. For OSI, the difference is 0% when stenosis is 16%, 18%, 26%. For RRT, the difference between the two is 0% when degree of stenosis is 18% and 84%. WSS exhibited an increasing trend with higher degrees of stenosis. TAWSS demonstrated significant variation in moderate to severe stenosis, while OSI increased markedly in cases of moderate to severe stenosis. High RRT values in severely stenotic regions indicated a propensity for atherosclerotic lesion development.
This study systematically quantified the discrepancies between Newtonian and non-Newtonian blood viscosity models in predicting hemodynamic parameters across different degrees of carotid artery stenosis. Statistical analyses revealed significant differences between the two models in WSS, TAWSS, OSI, and RRT ( < 0.001 for all parameters). Newtonian models, while computationally efficient, overestimated TAWSS, OSI, and RRT while underestimating WSS, particularly in moderate to severe stenosis. In contrast, non-Newtonian models provided more physiologically accurate predictions, especially in regions with high shear stress variations. The results emphasize the importance of selecting appropriate viscosity models for CFD-based patient-specific risk assessment, particularly in stroke prediction, plaque evaluation, and surgical planning. Non-Newtonian models should be prioritized in high-risk patients where flow disturbances are more pronounced, whereas Newtonian models remain suitable for early screening and rapid assessments.
颈动脉粥样硬化性血管疾病是中风的重要成因，会显著增加早期复发性缺血的风险。计算流体动力学（CFD）在预测颈动脉狭窄患者后续中风复发方面已显示出潜力。
本研究旨在探究不同粘度模型下四个关键血流动力学指标——壁面切应力（WSS）、时间平均壁面切应力（TAWSS）、振荡切变指数（OSI）和相对停留时间（RRT）——在计算时间和准确性上的差异，从而为临床病例提供最佳模型选择，并为临床医生的决策提供指导。
使用计算机断层血管造影（CTA）建立三维血管模型，随后进行CFD模拟以计算WSS、TAWSS、OSI和RRT。通过将模拟结果与Razavi等人（10.1016/j.jbiomech.2011.04.023）的结果进行比较来验证模拟的准确性。分析了不同狭窄程度和粘度模型下不同参数的数值误差。
在瞬态状态下，当狭窄程度为38%、72%-84%时，两者的性能差异小于6%。对于TAWSS，当狭窄程度为12%、18%、26%、54%和76%时，差异为0%。对于OSI，当狭窄程度为16%、18%、26%时，差异为0%。对于RRT，当狭窄程度为18%和84%时，两者的差异为0%。WSS随狭窄程度的增加呈上升趋势。TAWSS在中度至重度狭窄时表现出显著变化，而OSI在中度至重度狭窄病例中显著增加。严重狭窄区域的高RRT值表明有动脉粥样硬化病变发展的倾向。
本研究系统地量化了牛顿和非牛顿血液粘度模型在预测不同程度颈动脉狭窄的血流动力学参数方面的差异。统计分析显示，两种模型在WSS、TAWSS、OSI和RRT方面存在显著差异（所有参数P<0.001）。牛顿模型虽然计算效率高，但高估了TAWSS、OSI和RRT，同时低估了WSS，特别是在中度至重度狭窄时。相比之下，非牛顿模型提供了更符合生理的准确预测，尤其是在剪切应力变化较大的区域。结果强调了为基于CFD的患者特异性风险评估选择合适粘度模型的重要性，特别是在中风预测、斑块评估和手术规划中。在血流紊乱更明显的高危患者中，应优先选择非牛顿模型，而牛顿模型仍适用于早期筛查和快速评估。
