MRI of Structure and Function in Assessing Hemodynamic Impact on AAA Evolution

结构和功能 MRI 评估血流动力学对 AAA 进化的影响

• 批准号: 8717462
• 负责人: David A Saloner
• 金额: $ 45.61万
• 依托单位: NORTHERN CALIFORNIA INSTITUTE/RES/EDU
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-08 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8717462
• 关键词: Abdominal Aortic Aneurysm; Address; Affect; Age; Aneurysm; Aorta; Aortic Aneurysm; Aortic Diseases; Biochemical; Biological Markers; Biomechanics; Blood; Blood Vessels; Blood flow; Caliber; Cardiac; Caring; Characteristics; Clinical; Community Practice; Complex; Computer Simulation; Data Reporting; Data Set; Descriptor; Diagnosis; Disease; Disease Progression; Ensure; Evolution; FDA approved; Functional Imaging; Geometry; Growth; Guidelines; Image; Individual; Inflammation; Intervention; Kinetics; Liquid substance; Location; Longitudinal Studies; Magnetic Resonance Imaging; Measurement; Measures; Mediating; Methods; Modeling; Monitor; Morphology; Natural History; Operative Surgical Procedures; Outcome; Patient Monitoring; Patient observation; Patients; Phase; Physiologic pulse; Physiology; Play; Population; Prevalence; Procedures; Process; Recruitment Activity; Risk; Role; Rupture; Ruptured Aneurysm; Simulate; Staging; Stents; Structure; Thrombus; Time; Uncertainty; Vascular Diseases; Velocimetries; base; cohort; hemodynamics; in vitro Model; in vivo; iron oxide; non-compliance; premature; public health relevance; response; shear stress; simulation; tool

DESCRIPTION (provided by applicant): Abdominal Aortic Aneurysm (AAA) is a condition with potentially devastating outcomes if the aneurysm progresses to rupture. Although the evolution of AAA is a complex process that is likely mediated by an interplay of biochemical and biomechanical factors, and despite the geometrical and structural variability of the entity itself, current clinical criteria hinge on a single parameter - the maximal lumenal diameter. Under clinical guidelines, there is a large population of individuals who harbor aneurysms that have not yet reached a size (5.5 cms) where the benefit from surgical intervention (either open surgery or endovascular stent-graft placement) exceeds the risk of the procedure. These patients are then followed with watchful waiting. It is the hypothesis of this project that hemodynamic factors play an important role in determining whether a given aneurysm will progress more rapidly than would be estimated on the basis of maximal lumenal diameter alone. The project will develop advanced MRI capabilities to measure the geometric morphology of the vascular lumen and of any intralumenal thrombus that might be present. Imaging of functional characteristics such as vascular compliance and turbulent kinetic energy will also be implemented. Similarly, advanced Computational Fluid Dynamics (CFD) simulations will be performed to simulate, on a patient-specific basis, the velocity fields in these aneurysms. The simulations will include fluid-structur interactions, non-laminar effects, and non- Newtonian terms. Consistency of these methods will be checked in cross-comparison with one another, and against experimental flow models. A cohort of patients with aneurysms in the range from 3.5 to 5.0 cms will be recruited for bi-annual imaging. Interval data sets will be co-registered with each other and changes in aneurysm morphology will be measured. These changes will then be correlated with hemodynamic descriptors calculated for that specific aneurysm. Particular care will be taken to ensure that the project is formulated to provide data reporting and guidance that is directly relevant to the clinician in community practice. It is the hypothesis of this proposal that regions of reduced wall shear stress will correlate with regions of more rapid aneurysm growth. If this is indeed demonstrated to be the case, this project will provide the tools to identify patients who, despite relatively small aneurysm size, might be rapid progressors, and conversely, cases where patients with larger aneurysms might have relatively stable conditions. That information would be important in ensuring that rapid progressors are treated before they progress to rupture, and that patients with stable aneurysms can be spared premature surgeries.

描述（由申请人提供）：腹部主动脉瘤（AAA）是一种疾病，如果动脉瘤发展到破裂，则可能会有毁灭性的结果。尽管AAA的演变是一个复杂的过程，它可能是由生物化学和生物力学因素相互作用介导的，尽管实体本身的几何和结构可变性，但 当前的临床标准取决于单个参数 - 最大腔直径。根据临床指南，有大量的个体携带动脉瘤尚未达到尺寸（5.5 cms），其中手术干预受益（开放手术或血管内支架移植物的放置）超过了该手术的风险。然后随后等待这些患者。该项目的假设是，血液动力学因子在确定给定动脉瘤是否会比仅基于最大腔直径估算的要快的速度起着重要作用。该项目将开发高级MRI功能，以测量可能存在的任何可能存在的血管内管道的几何形态和任何肿瘤内血栓的形态。还将实施功能特征（例如血管合规性和湍流动能）的成像。同样，将进行高级计算流体动力学（CFD）模拟，以在患者特定的基础上模拟这些动脉瘤中的速度场。模拟将包括流体结构相互作用，非线中效应和非牛顿术语。这些方法的一致性将在彼此的交叉比较和实验流模型中进行检查。在3.5至5.0 cms的范围内，将招募一组动脉瘤患者进行双年成像。间隔数据集将彼此共同注册，并将测量动脉瘤形态的变化。这些变化将与针对该特定动脉瘤计算的血液动力学描述符相关。要特别注意确保 项目旨在提供与临床医生在社区实践中直接相关的数据报告和指导。这一提议的假设是壁还原区域 剪切应力将与动脉瘤生长更快的区域相关。如果确实证明情况确实如此，该项目将提供工具来识别患者，尽管动脉瘤大小相对较小，但可能是快速进步者，相反，患有较大动脉瘤的患者可能具有相对稳定的病例。该信息对于确保快速进步之前对其进行破裂的快速治疗将很重要，并且患有稳定动脉瘤的患者可以保留过早的手术。