Computational study of rupture of the cerebral aneurysms

蛛网膜下腔出血的主要原因是脑动脉瘤破裂。一旦发生蛛网膜下腔出血，死亡风险很高。当发现脑动脉瘤时，由于在目前情况下无法预测其破裂，因此通常对其进行手术。然而，脑动脉瘤的手术是困难的，并且不仅给患者带来身体负担，而且给患者带来经济负担。因此，预测个体动脉瘤破裂的危险因素，以防止不必要的手术是非常重要的。本研究旨在探讨脑血管几何形状和血流动力学之间的关系，以预测脑动脉瘤的破裂和创建。该项目的研究人员一直在开发一个数值模拟系统，该系统包括基于医学图像的几何建模，网格生成，有限元流体模拟和科学可视化。设计了一个数据库系统，用于组织和分析医学图像 ...更多信息 es、生理学和计算机图形或数字结果的电影，用于循证医学。此外，由于仿真系统假设动脉壁为刚性壁，因此研究了数值方法来处理血流-动脉壁相互作用问题的有效方法。本研究项目集中在以下三个主题：1）基于医学图像的仿真和数据库系统的开发2）血流-动脉壁相互作用的数值模拟3）数值结果与临床数据的比较对于主题1），对大脑中动脉（MCA）交界处进行了19例数值模拟。使用血管几何参数构建数据库系统，并使用19个病例的结果进行多变量分析以估计最大壁剪切应力。结果表明，与数值分析结果吻合较好。结果发现，MCA的直径，分支的直径比，MCA的，和分叉的角度之间的MCA和brunching动脉是重要的几何因素，在确定最大壁面剪应力。对于第二个问题，本文发展了一种血流与动脉壁相互作用的数值方法。将该方法应用于弯管模型和颈内动脉模型。结果发现，尽管动脉壁的变形很小，但弹性动脉壁对壁剪力分布的影响是显著的。最后，对于主题3），在帝京大学进行了20年的调查，并总结了结果，以研究未破裂动脉瘤与蛛网膜下腔出血之间的关系。少

A main cause of subarachnoidal hemorrhages is rupture of a cerebral aneurysm. Once the subarachnoidal hemorrhage occurs, there is a high risk of death. When the cerebral aneurysm is found, it is usually operated because its rupture can not be predicted under the present circumstance. However, an operation of the cerebral aneurysm is difficult and gives not only physical but also financial burdens to a patient. Thus it is quite important to predict a risk factor of individual aneurysm's rupture in order to prevent unnecessary surgeries.The research aims to investigate the relationship between cerebrovascular geometry and hemodynamics in order to predict rupture and creation of cerebral aneurysms. The investigators of the project have been developing a numerical simulation system, which consists of medical image-based geometric modeling, grid generation, finite element fluid simulation, and scientific visualization. A database system is designed so as to organize and analyze medical imag … More es, physiological, and computer graphics or movies of numerical results for the purpose of evidence-based medicine. In addition, since the simulation system assumes the arterial walls as rigid walls, numerical methods are investigated for an effective way to treat blood flow-arterial wall interaction problems.The present research project focuses on the following three topics : 1) Development of medical image-based simulation and database system 2) Numerical simulation of blood flow-arterial wall interaction 3) Comparison of numerical results with clinical dataAs for the topics 1), a total of 19 cases of numerical simulations are conducted for the middle cerebral artery (MCA) junction. The database system was constructed using vascular geometric parameters, and the multivariate analysis is performed using the results of 19cases to estimate a maximum wall shear stress. The results are compared and show good agreement with those of numerical analysis. It is found that diameter of the MCA, ratio of diameter of branching to that of the MCA, and difurcation angle between the MCA and brunching arteries are important geometric factors in determining maximum wall shear stresses. As for the topics 2), a numerical mothod for interaction between blood flow and arterial wall is developed. The method was applied to the curved pipe model and the Intermal Carotid artery model. As a result, it is found that effects of elastic arterial wall on the wall shear distribution is significant despite a small deformation of the arterial wall. Finally, for the topics 3), the survey had been conducted for 20 years at Teikyo University, and the results were summarized to study the relationship between unrupture aneurysms and subarachnoidal homerrhages. Less