Evaluation of Aortic Hemodynamics and Compliance in Aortic Stenosis

主动脉瓣狭窄的主动脉血流动力学和顺应性评估

• 批准号: 10057223
• 负责人: Michael Baran Scott
• 金额: $ 4.11万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-30 至 2023-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10057223
• 关键词: 3-Dimensional; 4D MRI; Address; Affect; Anatomy; Aneurysm; Angiography; Aorta; Aortic Aneurysm; Aortic Valve Stenosis; Area; Automation; Biological Markers; Blood; Blood Vessels; Breathing; Caliber; Cardiac; Clinical; Clinical Research; Collaborations; Complex; Complication; Congenital Heart Defects; Consumption; Data; Defect; Development; Diastole; Dilatation - action; Dimensions; Disease; Electrocardiogram; Ensure; Evaluation; Geometry; Goals; Growth; Guidelines; Heart Valves; Image; Impairment; Interobserver Variability; Interruption; Lead; Light; Magnetic Resonance Imaging; Manuals; Measurement; Measures; Methods; Operative Surgical Procedures; Outcome; Patient Recruitments; Patients; Phenotype; Pilot Projects; Population; Protocols documentation; Reference Standards; Reproducibility; Resolution; Resources; Respiration; Risk Assessment; Scanning; Severities; Speed; Staging; Systole; Techniques; Testing; Thoracic aorta; Three-dimensional analysis; Time; Tissues; Ultrasonography; Validation; Valsalva sinus; analysis pipeline; aortic valve; aortic valve disorder; ascending aorta; automated analysis; base; bicuspid aortic valve; clinical care; clinical imaging; clinical translation; cloud based; contrast enhanced; data analysis pipeline; hemodynamics; improved; indexing; method development; neuroimaging; patient population; respiratory; shear stress; translational scientist; volunteer

Project Summary Bicuspid aortic valve (BAV) is the most common congenital heart defect, and it predisposes patients to complications such as aortic stenosis (AS, most common cause) and aortic aneurysm. Current metrics are ineffective at distinguishing patients with BAV and TAV and concomitant AS, and management of AS in patients with BAV and trileaflet aortic valves (TAV) is nearly identical under current guidelines. Current clinical care involves ultrasound as well as CT or contrast enhanced MRI to generate angiograms, and surgical thresholds are based on diameters and growth rates in the ascending aorta. The goal of this project is to develop a high-resolution self-navigating bSSFP sequence and then combine it with 4D flow data in an automated pipeline to allow improved characterization of the anatomy and hemodynamics of the aorta. While 4D flow, a method pioneered in our lab, enables acquisition of temporally and spatially resolved 3D flow velocity without using contrast, the technique could be improved by incorporating higher-resolution scans with improved blood-tissue contrast. Delineation of the volume of the aorta in patients with AS from 4D flow data alone has also historically proven more challenging due to the presence of a high-speed flow jet. Clinical translation of 4D flow is also limited by a time-intensive analysis workflow, so this project includes both the sequence development aims as well as the goal of developing an automated cloud-based analysis pipeline for the data. Close collaboration with clinicians will ensure that calculated metrics are relevant and presented in a manner that could be useful in the clinical staging or management of these patients. The first aim of this proposal is development and validation of a balanced steady-state free-precession (bSSFP) sequence to collect improved anatomic data with high resolution and blood-tissue contrast to improve diameter measurements of the ascending aorta and enable segmentation of the aorta at several time points in the cardiac cycle. This will allow calculation of relative area change as a surrogate for aortic compliance and examination of the wall shear stress dynamics over the cardiac cycle. The second aim will incorporate this higher-resolution data and 4D flow data into a highly automated pipeline that will enable rapid segmentation of the aorta and calculation of the wall shear stress dynamics and relative area changes. In the third aim, 20 BAV and 20 TAV patients with AS will be recruited from the patient population at Northwestern, then imaged and analyzed using the new protocol. This will demonstrate the feasibility of using the method in a clinical setting, while also contributing to answering the question of if AS is a separate clinical entity in BAV and TAV patients. Clinical collaborators will help guide the project to fulfil the ultimate goal of improving clinical imaging and staging of these complex patients.

项目摘要 二叶式主动脉瓣（BAV）是最常见的先天性心脏病， 并发症，如主动脉瓣狭窄（AS，最常见的原因）和主动脉瘤。目前的指标是 在区分BAV和TAV患者以及合并AS时无效， 根据当前指南，BAV和三叶主动脉瓣（TAV）患者几乎相同。当前临床 护理包括超声以及CT或对比增强MRI以生成血管造影片， 阈值基于升主动脉中的直径和生长速率。该项目的目标是 开发高分辨率自导航bSSFP序列，然后将其与4D流数据联合收割机结合， 自动化流水线，以改善主动脉解剖结构和血液动力学的表征。 而4D流，一种在我们实验室开创的方法，能够采集时间和空间分辨的3D流 在不使用对比度的情况下，该技术可以通过将更高分辨率的扫描与 改善血液组织对比度。从4D血流数据描绘AS患者的主动脉容积 由于高速流动射流的存在，历史上也已经证明单独使用更具有挑战性。临床 4D流的翻译也受到时间密集型分析工作流程的限制，因此该项目包括 序列开发的目标以及开发自动化的基于云的分析管道的目标， 数据。与临床医生的密切合作将确保计算的指标是相关的，并以 这种方法可能有助于这些患者的临床分期或管理。 本建议的第一个目的是发展和验证一个平衡的稳态自由进动 （bSSFP）序列，以收集具有高分辨率和血液-组织对比度的改进解剖数据， 测量升主动脉的直径，并能够在几个时间点分割主动脉， 心动周期。这将允许计算相对面积变化作为主动脉顺应性的替代， 检查心动周期内的壁剪切应力动力学。第二个目标将包括这一点 更高分辨率的数据和4D流数据到一个高度自动化的管道，这将使快速分割的 并计算主动脉壁面剪应力的动态变化及相对面积。在第三个目标中，20 BAV 将从西北大学的患者人群中招募20名患有AS的TAV患者，然后进行成像， 使用新协议进行分析。这将证明在临床环境中使用该方法的可行性， 同时也有助于回答AS是否是BAV和TAV患者的独立临床实体的问题。 临床合作者将帮助指导该项目，以实现改善临床成像的最终目标， 对这些复杂的患者进行分期。