Improving the computational modeling of coiled cerebral aneurysms through synchrotron microtomography

通过同步加速器显微断层扫描改进盘绕脑动脉瘤的计算模型

• 批准号: 10301590
• 负责人: Michael Robert Levitt
• 金额: $ 8.73万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10301590
• 关键词: 3D Print; Anatomy; Aneurysm; Blood flow; Brain Aneurysms; Brain hemorrhage; Cerebral Aneurysm; Cessation of life; Clinical; Complex; Computer Models; Computing Methodologies; Equation; European; Funding; Future; Geometry; Goals; Health Care Costs; Hospitalization; Image; In Vitro; Liquid substance; Measurement; Measures; Methods; Modeling; Patients; Permeability; Porosity; Predictive Value; Prevalence; Prognosis; Recurrence; Reference Standards; Resolution; Retreatment; Risk; Rupture; Scanning; Source; Structure; Synchrotrons; Techniques; Three-Dimensional Image; Treatment Efficacy; Treatment Failure; Treatment outcome; United States National Institutes of Health; base; clinically relevant; disability; hemodynamics; high standard; improved; microCT; novel; research facility

Here we seek to improve the accuracy of hemodynamic modeling of coiled cerebral aneurysms. This goal is significant due to the prevalence of cerebral aneurysms, their dismal prognosis when ruptured, and treatment failure rates (resulting in aneurysm recurrence and risk of either brain hemorrhage or need for retreatment) of up to 25%. Hemodynamic forces are thought to influence aneurysm treatment outcomes, but the standard method of computational fluid dynamics (CFD) modeling of such forces within coiled aneurysms (termed the “porous medium technique”) is error-prone. Improving the accuracy of CFD modeling of coiled aneurysms will strengthen the predictive value of patient-specific CFD, which could improve aneurysm treatment efficacy and reduce death and disability, as well as health care costs associated with multiple hospitalizations. This project builds on our ongoing NIH-funded expertise at creating CFD models of brain aneurysms, and a partnership with the European Synchrotron Research Facility, to develop an improved method of CFD modeling of coiled cerebral aneurysms that can be applied in a clinical setting. First, we will create high-fidelity 3D-printed aneurysm models based on patient-specific aneurysm anatomy, and place the same commercially- available aneurysm coils used in actual patient treatment into each model. These coiled aneurysm models will be scanned at 12 µm resolution using synchrotron x-ray microtomography, providing detailed 3D images of the complex coil geometry. These images will be incorporated into CFD models of clinically relevant hemodynamic variables, and will be considered a reference standard to which other modeling techniques are compared. Then, we will create a new set of CFD models of the same aneurysms, using the standard porous medium technique to represent the coil mass. This technique simplifies the complex coil geometry into a material of uniform porosity, which our preliminary analysis suggests is a source of significant error in the calculation of hemodynamic variables. We will quantify this error by comparing these CFD models to the reference standard CFD models created using microtomography. Then, we will employ the homogenization of multiple scale expansions technique, in which the complex structure of the coil mass is represented by macroscopic equations that better approximate permeability. We will develop a set of corrective factors (a “coil modeling toolkit”) that can be used in future CFD models of coiled aneurysms with better accuracy than the standard porous medium technique. Finally, we will determine the improved accuracy of this technique by using the coil modeling toolkit to create CFD models of a new set of aneurysms, for which 3D-printing and microtomography are not required. We will compare these results to the reference standard (both using CFD and using in vitro flow measurements through 3D-printed models) and quantify the improvement in accuracy gained using the coil modeling toolkit. This improved accuracy will strengthen the clinical impact of CFD studies of aneurysm treatment.

在这里，我们寻求提高盘绕脑动脉瘤血流动力学建模的准确性。这个目标是 由于脑动脉瘤的普遍存在、破裂后的不良预后以及治疗方法，这一点非常重要 失败率（导致动脉瘤复发和脑出血或需要再治疗的风险） 高达 25%。血流动力学被认为会影响动脉瘤的治疗结果，但标准 计算流体动力学 (CFD) 方法对盘绕动脉瘤内的此类力进行建模（称为 “多孔介质技术”）很容易出错。提高盘绕动脉瘤 CFD 建模的准确性将 增强患者特异性 CFD 的预测价值，从而提高动脉瘤治疗效果 减少死亡和残疾，以及与多次住院相关的医疗费用。 该项目建立在我们持续的 NIH 资助的创建脑动脉瘤 CFD 模型的专业知识的基础上， 并与欧洲同步加速器研究机构合作，开发改进的 CFD 方法 可应用于临床环境的盘绕脑动脉瘤建模。首先，我们将打造高保真 基于患者特定动脉瘤解剖结构的 3D 打印动脉瘤模型，并将相同的商业化 每个模型中都有实际患者治疗中使用的可用动脉瘤弹簧圈。这些盘绕动脉瘤模型将 使用同步加速器 X 射线显微断层扫描以 12 µm 分辨率进行扫描，提供详细的 3D 图像 复杂的线圈几何形状。这些图像将被纳入临床相关血流动力学的 CFD 模型中 变量，并将被视为与其他建模技术进行比较的参考标准。 然后，我们将使用标准多孔模型创建一组新的相同动脉瘤的 CFD 模型 中等技术来表示线圈质量。该技术将复杂的线圈几何形状简化为 均匀孔隙率的材料，我们的初步分析表明这是显着误差的来源 血流动力学变量的计算。我们将通过将这些 CFD 模型与 使用显微断层扫描创建的参考标准 CFD 模型。 然后，我们将采用多尺度扩展的同质化技术，其中复杂的 线圈质量的结构由更能近似磁导率的宏观方程表示。我们 将开发一套可用于未来 CFD 模型的校正因子（“线圈建模工具包”） 与标准多孔介质技术相比，具有更好的准确性。 最后，我们将通过使用线圈建模工具包来确定该技术提高的准确性 创建一组新动脉瘤的 CFD 模型，不需要 3D 打印和显微断层扫描。 我们将这些结果与参考标准进行比较（使用 CFD 和体外流量测量） 通过 3D 打印模型）并量化使用线圈建模工具包所获得的精度改进。 这种准确性的提高将增强 CFD 研究对动脉瘤治疗的临床影响。