In Vivo IVUS Image-Based Modeling for Human Coronary Plaque Assessment

项目描述（由申请人提供）：本项目旨在将各向异性计算模型与体内血管内超声（IVUS）、血管造影、离体磁共振成像（MRI）、力学测试和病理组织学分析相结合，分析动脉粥样硬化易损斑块，确定关键血流和斑块应力/应变指标，定量评估冠状动脉斑块易损。长期目标是：a)开发计算机械图像分析工具，以更准确地评估斑块，并可能对目前美国心脏协会（AHA）斑块分类方案进行定量改进；B)识别可监测的关键血流和应激/应变斑块易损性风险指标，用于相关心血管疾病的早期预测、诊断、治疗和预防。假设是：(1)斑块的临界应力/应变条件与斑块易损密切相关，可作为进一步区分AHA高级斑块分类（V- VIII型）斑块的指标，并为评估斑块破裂风险提供更定量的方法；(2)体内IVUS成像、压力和流量测量与三维各向异性多组分流固相互作用（FSI）和循环弯曲模型相结合，将提高冠状动脉斑块力学分析的准确性，从而更准确地评估体内斑块易损性。这个项目有四个具体目标。目标1：开发和整合体内IVUS成像、血流和压力测量技术、血管造影、多对比离体MRI、组织学分析和双轴力学测试技术，以量化斑块形态、组织成分、曲率、病变部位冠状动脉内血流和压力状况，以及各向异性血管材料特性。目的2：针对100个人类冠状动脉斑块（50个体内IVUS， 50个离体MRI），在循环弯曲和冠状动脉内血流和压力条件下（仅IVUS）建立三维各向异性多组分FSI模型，获得三维血流剪切应力和斑块应力/应变数据；目标3：对冠状动脉斑块进行三维机械图像分析，确定临界应力/应变条件（潜在风险指标）与斑块形态和组成、血管力学特性和血流压力条件（患者数据）之间的相关性。计算模型将通过体内IVUS和体外实验数据进行验证。目的4：引入定量的体内/离体/组织学斑块易损性评估方案，并与AHA基于组织学的斑块分类进行比较，以可能对AHA方案进行定量改进和潜在的筛选实践。该项目的成功将导致更准确的斑块易损性评估和预测可能的斑块破裂风险，从而可以做出更好的治疗决策，从而改善公众健康并降低医疗保险成本。机械图像分析和软件添加，以增强MRI/IVUS成像技术的临床应用是可能的，未来大规模的患者研究验证。

DESCRIPTION (provided by applicant): The objective of this project is to combine anisotropic computational modeling with in vivo intravascular ultrasound (IVUS), angiography, ex vivo Magnetic Resonance Imaging (MRI), mechanical testing, and pathohistological analysis to analyze vulnerable atherosclerotic coronary plaques and identify critical blood flow and plaque stress/strain indicators for quantitative coronary plaque vulnerability assessment. The long term goals are: a) develop computational mechanical image analysis tools for more accurate plaque assessment and possible quantitative improvement to the current American Heart Association (AHA) plaque classification scheme; b) identify critical flow and stress/strain plaque vulnerability risk indicators which could be monitored for early prediction, diagnosis, treatment, and prevention of related cardiovascular diseases. The hypotheses are: (1) Critical plaque stress/strain conditions correlate closely with plaque vulnerability and may be used as indicators to further differentiate plaques within AHA advanced plaque classifications (types V- VIII) and provide more quantitative methods to assess plaque rupture risk; (2) Combination of in vivo IVUS imaging, pressure and flow measurements and 3D anisotropic multi-component models with fluid-structure interactions (FSI) and cyclic bending will improve the accuracy of mechanical analysis for coronary plaques and lead to more accurate in vivo plaque vulnerability assessment. This project has four specific aims. Aim 1: Develop and integrate in vivo IVUS imaging, flow and pressure measurements techniques, angiography, multi-contrast ex vivo MRI, histological analysis, and biaxial mechanical testing techniques to quantify plaque morphology, tissue components, curvature, intra-coronary flow and pressure conditions at the lesion site, and anisotropic vessel material properties. Aim 2: Develop 3D anisotropic multi-component FSI models for 100 human coronary plaques (50 in vivo IVUS, 50 ex vivo MRI) with cyclic bending and intra-coronary flow and pressure conditions (IVUS only) to obtain 3D flow shear stress and plaque stress/strain data; Aim 3: perform 3D mechanical image analysis for coronary plaques and identify correlations between critical stress/strain conditions (potential risk indicators) and plaque morphology and composition, vessel mechanical properties and blood flow pressure conditions (patient data). Computational models will be validated by both in vivo IVUS and in vitro experimental data. Aim 4: Introduce quantitative in vivo/ex vivo/histological plaque vulnerability assessment schemes and compare with AHA histology-based plaque classifications for possible quantitative improvements on AHA scheme and potential screening practice. Success of this project will lead to more accurate plaque vulnerability assessment and predictions for possible plaque rupture risk so that better decisions for treatment can be made leading to better public health and reduced costs of Medicare. Mechanical image analysis and software additions to enhance MRI/IVUS imaging technology for clinical applications are possible with future large-scale patient study validations. PUBLIC HEALTH RELEVANCE: Many cardiovascular events (such as heart attack and stroke) are caused by atherosclerotic plaque rupture which may happen without any warning signals. Success of this project will lead to more accurate in vivo coronary plaque vulnerability assessment and predictions for possible plaque rupture risk so that better and timely decisions for treatment can be made leading to better public health and reduced costs of Medicare. Commercialization of the research results is possible with the automation of model construction and data analysis procedures.