颅内囊性动脉瘤虚拟壁厚和破裂风险相关性研究

发布时间：2018-05-05 03:35

本文选题：颅内动脉瘤 + 囊状　；参考：《苏州大学》2014年博士论文

【摘要】：目的以个体特异性动脉瘤模型为基础，探索计算机数值模拟颅内囊性动脉瘤“虚拟壁厚”分布的方法，分析“虚拟壁厚”与动脉瘤破裂风险之间的关系，为未破裂动脉瘤临床预防和治疗提供理论依据。方法 1.以动脉瘤患者头颅CTA扫描获取的DICOM图像为基础，使用VMTK血管建模工具包，在Pypepad中应用移动立方体提取剪切感兴趣区，使用水平集法等建立动脉瘤血管段的三维表面模型。 2.使用VMTK血管建模工具包结合Python软件，通过计算表面三维模型的Voronoi图、计算中心线、重建中心线、切割Voronoi图、修补Voronoi图和重建等步骤，建立动脉瘤形成前的原始载瘤血管三维模型。 3.动脉瘤三维表面模型和重建的载瘤动脉在Geomagic Studio中分别处理为模具和型坯，在前处理器Gambit中进行网格划分、定义边界和计算域，使用ANSYSPOLYFLOW软件数值模拟分析“虚拟壁厚”分布。 4.采用Geomagic Studio逆向建模软件，通过一系列的切割、复制、缩放、变形、组合和测量等操作，达到连续修改某一几何参数，建立多个局部几何特征改变的系列三维表面模型。对各个系列的三维几何变形模型分别进行“虚拟壁厚”数值模拟计算，分析单个几何参数和“虚拟壁厚”的之间的相关性，，初步验证“虚拟壁厚”的科学性。 5.对80个破裂及未破裂动脉瘤分别进行“虚拟壁厚”数值模拟分析，评估“虚拟壁厚”和动脉瘤破裂风险之间的关系；并通过15名新诊治动脉瘤患者对“虚拟壁厚”参数进行初步临床验证；尝试分析“虚拟壁厚”参数和蛛网膜下腔出血量（Fisher分级）的相关性。结果 1.使用VMTK血管建模工具包能顺利建立动脉瘤三维表面模型，重建后能较好显示动脉瘤表面的小疱等微小几何结构。 2.在VMTK血管工具包和Python软件中，通过人机互动的方式，计算机能自动重建去除动脉瘤后的载瘤血管模型。 3.型坯、模具在Gambit软件中能顺利划分网格、定义边界和计算域，并可以通过Polyflow软件进行“虚拟壁厚”数值模拟。 4.使用逆向建模软件的各种编辑功能，在仅改变单个几何参数的情况下顺利建立瘤高变化系列模型、瘤宽变化系列模型、瘤颈变化系列模型和体积变化系列模型。“虚拟壁厚”和单个几何参数的变化曲线显示两者具有相关性。 5.破裂组和未破裂组的最薄“虚拟壁厚”变薄倍数有统计学差异（P0.05），ROC曲线下面积为0.807（95％信心区间[CI]，0.711-0.904），评估破裂风险能力明显优于AR和SR；相对最佳临界值为19.94倍，临床初步验证有效；“虚拟壁厚”参数和蛛网膜下腔出血量有相关性。结论探索出了一种计算机数值模拟颅内动脉瘤“虚拟壁厚”的技术方法，“虚拟壁厚”和几何特征参数之间，以及和动脉瘤破裂风险之间均存在相关性，“虚拟壁厚”可以作为评估动脉瘤破裂风险的一个参数。
[Abstract]:Purpose Based on the individual specific aneurysm model, the computer simulation method of "virtual wall thickness" distribution of intracranial cystic aneurysm was explored, and the relationship between "virtual wall thickness" and the risk of aneurysm rupture was analyzed. To provide theoretical basis for clinical prevention and treatment of unruptured aneurysms. Method 1. Based on the DICOM images obtained by CTA scan of aneurysm patients, the 3D surface model of aneurysm vascular segment was established by using the VMTK vascular modeling kit, the moving cube was used to extract the region of interest in shear in Pypepad, and the horizontal set method was used to establish the three-dimensional surface model of the aneurysm vascular segment. 2. Using VMTK vascular modeling tool kit and Python software, by calculating the Voronoi diagram of 3D surface model, calculating the center line, reconstructing the center line, cutting Voronoi diagram, repairing Voronoi diagram and reconstructing, etc. A three-dimensional model of primordial aneurysm carrying vessels was established before the formation of aneurysms. 3. The three-dimensional surface model of the aneurysm and the reconstructed aneurysm carrying artery are treated as molds and billets in Geomagic Studio respectively. The pre-processor Gambit is used to mesh the aneurysm, define the boundary and compute domain, and use ANSYSPOLYFLOW software to simulate and analyze the "virtual wall thickness" distribution. 4. Through a series of operations, such as cutting, copying, scaling, deforming, combining and measuring, Geomagic Studio reverse modeling software is used to continuously modify a certain geometric parameter and establish a series of 3D surface models with local geometric features changing. The three dimensional geometric deformation models of each series are simulated and calculated respectively, and the correlation between the single geometric parameter and the virtual wall thickness is analyzed, and the scientific nature of the virtual wall thickness is preliminarily verified. 5. The "virtual wall thickness" of 80 ruptured and unruptured aneurysms was analyzed to evaluate the relationship between the "virtual wall thickness" and the risk of aneurysm rupture. The "virtual wall thickness" parameters were preliminarily verified in 15 newly diagnosed and diagnosed aneurysms, and the correlation between the "virtual wall thickness" parameters and the subarachnoid hemorrhage volume (Fisher grade) was analyzed. Result 1. The three-dimensional surface model of the aneurysm can be successfully established by using the VMTK vascular modeling kit, and the small geometric structure such as the vesicles on the surface of the aneurysm can be well displayed after reconstruction. 2. In the VMTK vascular toolkit and Python software, the computer can automatically reconstruct the tumor carrying vessel model after the removal of aneurysm by man-machine interaction. 3. The billet and die can be meshed smoothly in Gambit software, and the boundary and calculation field can be defined, and the "virtual wall thickness" numerical simulation can be carried out by Polyflow software. 4. Using various editing functions of reverse modeling software, the series models of tumour height change, tumour width change, neck change and volume change are successfully established under the condition of changing only a single geometric parameter. The virtual wall thickness and the variation curve of a single geometric parameter show a correlation between the two. 5. The thinning times of the thinnest "virtual wall thickness" of rupture group and unruptured group were statistically different. The area under ROC curve was 0.807 ~ 95% confidence interval [CI] 0.711-0.904, the ability to assess rupture risk was obviously superior to that of AR and SRS, the relative optimum critical value was 19.94 times, and the clinical preliminary verification was effective. There was a correlation between the parameters of virtual wall thickness and the amount of subarachnoid hemorrhage. Conclusion A computer numerical simulation method for the "virtual wall thickness" of intracranial aneurysms has been developed. There is a correlation between "virtual wall thickness" and geometric characteristic parameters, as well as with the risk of aneurysm rupture. Virtual wall thickness can be used as a parameter to assess the risk of aneurysm rupture.
【学位授予单位】：苏州大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R743.3

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