...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Biomechanics >Realistic non-Newtonian viscosity modelling highlights hemodynamic differences between intracranial aneurysms with and without surface blebs
【24h】

Realistic non-Newtonian viscosity modelling highlights hemodynamic differences between intracranial aneurysms with and without surface blebs

机译：逼真的非牛顿粘度模型强调了颅内动脉瘤在有或没有表面起泡时的血流动力学差异

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Most computational fluid dynamic (CFD) simulations of aneurysm hemodynamics assume constant (Newtonian) viscosity, even though blood demonstrates shear-thinning (non-Newtonian) behavior. We sought to evaluate the effect of this simplifying assumption on hemodynamic forces within cerebral aneurysms, especially in regions of low wall shear stress, which are associated with rupture. CFD analysis was performed for both viscosity models using 3D rotational angiography volumes obtained for 26 sidewall aneurysms (12 with blebs, 12 ruptured), and parametric models incorporating blebs at different locations (inflow/outflow zone). Mean and lowest 5% values of time averaged wall shear stress (TAWSS) computed over the dome were compared using Wilcoxon rank-sum test. Newtonian modeling not only resulted in higher aneurysmal TAWSS, specifically in areas of low flow and blebs, but also showed no difference between aneurysms with or without blebs. In contrast, for non-Newtonian analysis, blebbearing aneurysms showed significantly lower 5% TAWSS compared to those without (p = 0.005), despite no significant difference in mean dome TAWSS (p=0.32). Non-Newtonian modeling also accentuated the differences in dome TAWSS between ruptured and unruptured aneurysms (p < 0.001). Parametric models further confirmed that realistic non-Newtonian viscosity resulted in lower bleb TAWSS and higher focal viscosity, especially when located in the outflow zone. The results show that adopting shearthinning non-Newtonian blood viscosity in CFD simulations of intracranial aneurysms uncovered hemodynamic differences induced by bleb presence on aneurysmal surfaces, and significantly improved discriminant statistics used in risk stratification. These findings underline the possible implications of using a realistic model of blood viscosity in predictive computational hemodynamics. (C) 2014 Elsevier Ltd. All rights reserved.
机译：即使血液显示出剪切稀化（非牛顿）行为，大多数动脉瘤血流动力学的计算流体动力学（CFD）模拟都假定粘度恒定（牛顿）。我们试图评估这种简化假设对脑动脉瘤内血液动力的影响，尤其是在低壁切应力区域（与破裂有关）中。对两种粘度模型都进行了CFD分析，使用的是为26个侧壁动脉瘤（12个有气泡，12个破裂）获得的3D旋转血管造影体积，以及在不同位置（流入/流出区域）合并有气泡的参数模型。使用Wilcoxon秩和检验比较了在球顶上计算的时间平均壁切应力（TAWSS）的平均值和最低5％值。牛顿模型不仅导致较高的动脉瘤TAWSS，特别是在低流量和起泡区域，而且还显示出有或没有起泡的动脉瘤之间没有差异。相比之下，对于非牛顿分析，尽管平均穹顶TAWSS没有显着差异（p = 0.32），但有斑点的动脉瘤显示出5％的TAWSS相比没有明显的降低（p = 0.005）。非牛顿模型也突显了破裂和未破裂的动脉瘤之间穹顶TAWSS的差异（p <0.001）。参数模型进一步证实，实际的非牛顿粘度导致较低的气泡TAWSS和较高的粘滞粘度，尤其是位于流出区域时。结果表明，在颅内动脉瘤的CFD模拟中采用剪切稀化的非牛顿血液粘度可发现动脉瘤表面存在气泡引起的血流动力学差异，并显着改善了用于风险分层的判别统计数据。这些发现强调了在预测的计算血流动力学中使用现实的血液粘度模型可能产生的影响。 （C）2014 Elsevier Ltd.保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号