流固耦合分析分层的腹主动脉瘤模型

Layered abdominal aortic aneurysm model based on fluid-structure interaction

目的应用基于CT图像的三维重构技术,分别构建血管壁3层模型和单层模型,并应用流固耦合计算流体力学方法对这两种模型进行数值模拟。通过比较两者的血流动力学结果,讨论了两种应力模型的优劣,为深入研究血液流动状态与动脉疾病的关系提供帮助。方法采集腹主动脉瘤(AAA)临床CT图像,格式为DICOM,层间距为0.5mm,每片图像的平面分辨率为512×512,像素大小为0.5mm。应用医学图像后处理软件构建血管壁3层模型和单层模型,并应用流固耦合方法进行血流动力学模拟计算。结果经过多次迭代耦合计算,获得血管壁形变、等效应力等相关血流动力学参数。血管壁位移比较,单层血管壁模型B部分区域的血管壁变形情况略高于3层血管壁模型A,如腹主动脉分叉处模型A变形为1.041×10-3m,而模型B变形为1.171×10-3 m。血管壁应力分布比较,相同位置的3层血管壁模型的Von Mises值明显高于单层血管壁模型。结论通过对血管壁的变形及等效压力的分析,以及与单层血管壁模型的流固耦合模拟结果对比,得出了血管壁中层结构的变形和受力情况是AAA的形成和破裂的关键,为深入研究血流动力学与AAA疾病的关系提供帮助。

Objective To construct 2 models of three layered vessel wall and single layered vessel wall based on three-dimensional CT image reconstruction technique and perform numerical simulation by fluid-structure interaction（FSI）, and study the advantages and disadvantages of 2 models for further research on hemodynamic and the relationship of abdominal arterial aneurysm（AAA） diseases. Methods The clinical CT image of AAA was adopted, the format was DICOM, and layer distance of0.5 mm, plane resolution of 512 × 512 and pixel size of 0.5 mm. The medical image post-processing software was applied to reconstruct the three layered vessel wall model and the single layered vessel wall model for hemodynamic simulation based on fluid-structure interaction（FSI） method. Results After several interactions coupling calculation, obtained the hemodynamic parameters of vessel wall deformation, Von Mises and so on. Conclusion It is demonstrated that in analyzing deformation and Von Mises of vessel wall, and discusses differences of 2 model results, which confirm the media layer deformation and stress distribution of blood vessel walls are the key to the formation and rupture of AAA. It is provides technical support for further research on hemodynamic and the relationship of AAA diseases.