Geometric Surrogates for Clinical Management of Abdominal Aortic Aneurysms

 描述（由申请人提供）：本提案将研究以下假设：与最大动脉瘤直径的临床标准相比，预测随后的峰值壁破裂风险指数（PWRRI）的几何替代物的量化将提供动脉瘤破裂风险的改进估计。因此，我们建议高度创新地使用放射学和非放射学临床成像来开发一种计算工具，该工具可以比当前临床标准更准确地评估AAA破裂风险。这种工具将允许准确量化单个AAA几何结构， 实现本研究的主要目标，即识别作为患者特异性PWRRI替代物的患者特异性AAA几何结构特征。在所提出的方法中，我们将首先计算一个真正个性化的PWRRI的基础上的创新方法称为基于图像的血管力学表征技术（iV-MeCh）。与PWRRI高度相关的几何特征将被视为该基于生物力学的指数的替代物。研究的第二阶段将是用实际临床结果验证替代物，这将产生破裂的准确预测因子。这种方法，没有复杂的有限元建模，并基于一个快速的，几乎自动化的几何量化计算工具，将提供一个特殊的理由需要手术干预，并具有重大的临床意义。因此，在项目期间将完成以下具体目标，以解决上述假设：（1）用于估计患者特定时空AAA壁应力的iV-MeCh;（2）使用iV-MeCh计算高和低破裂AAA风险的个体PWRRI;（3）识别作为PWRRI替代品的个体几何特征;和（4）评估几何替代物对预测AAA破裂风险的临床意义。本研究的主要结果是能够消除或揭开AAA破裂风险的神秘面纱，因为标准治疗（最大直径）不是评估其风险状况的准确指标。与推荐择期修复的传统最大直径截止值相比，PWRRI的几何替代物被假设为减少假阳性和假阴性。此外，PWRRI是通过一种新的、新颖的技术（iV-MeCh）来预测的，该技术通过非放射性临床成像来估计动脉瘤中的壁应力，而不使用构成性软组织力学。

 DESCRIPTION (provided by applicant): This proposal will investigate the following hypothesis: that the quantification of geometric surrogates, which predict the ensuing peak wall rupture risk index (PWRRI), will provide an improved estimate of aneurysm rupture risk compared to the clinical standard of maximum aneurysm diameter. We thus propose the highly innovative use of both radiological and non-radiological clinical imaging to develop a computational tool that can assess AAA risk of rupture with greater accuracy than the current clinical standard. Such a tool will allow the accurate quantification of individual AAA geometry to achieve the main goal of the study, which is to identify the patient-specific AAA geometry characteristics that are surrogates for patient-specific PWRRI. In the proposed approach, we will first compute a truly individualized PWRRI based on an innovative method called image-based Vascular Mechanical Characterization technology (iV-MeCh). The geometry characteristics highly correlated with PWRRI will be considered the surrogates of this biomechanics-based index. A second phase of the study will be the validation of the surrogates with actual clinical outcomes, which will yield the accurate predictors of rupture. This approach, devoid of complex finite element modeling and based on a fast, nearly automated computational tool for geometry quantification, would provide an exceptional rationale for the need for surgical intervention and be of major clinical significance. Therefore, the following specific aims are to be completed during the project period to address the aforementioned hypothesis: (1) Validate iV-MeCh for estimating patient-specific spatio-temporal AAA wall stress; (2) Calculate individual PWRRI using iV-MeCh for high and low risk of rupture AAA; (3) Identify the individual geometry characteristics that are surrogates of PWRRI; and (4) Assess the clinical significance of geometric surrogates for the prediction of AAA rupture risk. The primary outcome of this research will be the ability to disambiguate or demystify rupture risk in AAA for which the standard of care (maximum diameter) is not an accurate metric for assessing their at-risk condition. The geometric surrogates of PWRRI are hypothesized to reduce false positives and false negatives compared to the conventional maximum diameter cut-off for recommending elective repair. In addition, PWRRI is predicted by means of a new, novel technique (iV-MeCh), which estimates wall stress in aneurysms by means of non-radiological clinical imaging and without the use of constitutive soft tissue mechanics.