基于CT的脑动脉瘤双向流固耦合数值模拟研究

Numerical simulation study on bi-directional fluid-solid coupled model of aneurysm based on computed tomography angiography

摘要:

目的：探讨基于动脉瘤壁与动脉血管壁厚度不一的脑动脉瘤双向流固耦合数值模型的建模方法。方法：用MIMICS16.0软件提取1例患者颅内动脉瘤CT影像DICOM数据，获得动脉瘤体的初步模型。将该模型导入逆向工程软件Geomagic Studio 12，以及UGS NX 8.5进一步处理后，得到厚度不一的脑动脉瘤三维几何模型。运用ANSYS Workbench 15.0软件进行双向流固耦合计算，并分析瘤体内血流特性及动脉瘤壁所受应力应变情况。结果：快速准确地建立了厚度不一的动脉瘤双向流固耦合模型，清晰地模拟出1个心动周期内动脉瘤表面剪切应力、表面变形及速度流线的变化情况。结论：应用上述方法能够快速准确地建立动脉瘤的双向流固耦合模型，且相较于刚性模型和厚度一致的动脉瘤体模型更准确和实用。可以为动脉瘤介入治疗模拟研究提供优良的模型参数。

Abstract:

Objective：To explore the method of establishing the bi-directional fluid-solid coupled numerical model based on different thicknesses of aneurysms and arterial wall. Methods：The data series of aneurysm in a patient were got by computed tomography an－giography（CTA） image data. The data series were processed to obtain a surface model of the aneurysm’s vessel segment using MIM－ICS 16.0. The surface model was imported into Geomagic Studio 12.0 and UGS NX 8.5，which were processed to get the bi-directional fluid-solid coupled numerical model of aneurysm. ANSYS Workbench 15.0 software was used to calculate and to evaluate the charac－teristics of intratumoral blood and the stress and strain that Aneurysm wall suffered. Results：The bi-directional fluid-solid coupled model of aneurysm was established successfully and accurately，and it also clearly simulated the blood flow of the intracranial aneurysm，the deformation of the solid wall and velocity of flow lines in a cardiac cycle. Conclusion：Using the above method，the bi-directional fluid-solid coupled model of the aneurysm is established quickly and accurately，which is more accurate and useful than the rigid model and the same thickness aneurysm model. It can also provide excellent model parameters for simulating study of inter－ventional therapy of aneurysm.