Novel MR imaging and analysis of the dynamic microvascular network

动态微血管网络的新型 MR 成像和分析

• 批准号: RGPIN-2019-06137
• 负责人: Cheng, HaiLing
• 金额: $ 2.48万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=738734
• 关键词: Novel; MR; imaging; analysis; dynamic

The small blood vessel (microvascular) network is a highway connecting all the cells in our body, controlling blood pressure and allowing the exchange of nutrients and wastes. Even more sophisticated than an urban roadway network, the microvascular network can adaptively increase or reduce "speed limits" and the number of open "roads" and "lanes" to ensure the most efficient transport of sufficient goods to where it is needed in the body. Platforms that open a window on the microvasculature and enable detailed characterization in vivo are absolutely critical to our understanding of how mature microvessels are regulated and how new ones grow during development and repair. Existing whole-body imaging technologies such as magnetic resonance imaging (MRI), CT, and ultrasound can assess blood flow but not vasomodulation (change in vessel diameter), a much more complex phenomenon whereby local blood flow is adjusted in response to altered physiological demands. A technology gap currently exists, because just as we cannot say a two-lane highway can prevent traffic congestion at all times, we also cannot judge the performance of the microvascular network on perfusion status alone. In this NSERC application, we propose a research program to fill this gap by building on our long-standing expertise in microvascular MRI to augment the capabilities of a transformative platform we recently developed for assessing vasomodulation - the first ever dynamic MRI technology for perturbing and measuring vasomodulation in deep tissue. We will generalize our technology to the whole body by tackling the two remaining organs that are challenging for different reasons: the rapidly beating heart (challenge: motion) and skeletal muscle (challenge: low perfusion). Specifically, we will design novel acquisitions for near real-time cardiac MRI of the heart, develop mathematical models to sensitize measurements in low perfusion settings, and integrate these capabilities to understand how blood flow is adjusted synchronously in different organs to maintain normal blood pressure. Collectively, this work will advance the state-of-the-art in quantitative physiological imaging of the microvascular network, creating new technologies with broad applications in fundamental physiology studies, diagnostic medical imaging, and novel tissue engineering and regeneration paradigms. Furthermore, the proposed research offers exceptional opportunities for training graduate and undergraduate students in the core natural sciences and engineering (electrical engineering, mathematics, physiology) within an interdisciplinary context. The scientific knowledge and skills they acquire will enable them to make long-term impact and to lead their own initiatives at the interface of engineering and the life sciences.

小血管(微血管)网络是连接我们体内所有细胞的高速公路，控制血压，允许营养物质和废物的交换。微血管网络甚至比城市道路网更复杂，它可以自适应地增加或减少“限速”以及开放的“道路”和“车道”的数量，以确保将足够的货物以最有效的方式运输到身体需要的地方。打开微血管系统的窗口并在体内进行详细表征的平台对于我们理解成熟的微血管是如何受到调控以及新的微血管在发育和修复过程中如何生长至关重要的。现有的全身成像技术，如磁共振成像(MRI)、CT和超声波，可以评估血液流动，但不能评估血管调节(血管直径变化)，这是一种更复杂的现象，即局部血流量根据改变的生理需求进行调整。目前存在一个技术空白，因为正如我们不能说双车道高速公路可以一直防止交通拥堵一样，我们也不能仅凭血流状态来判断微血管网络的性能。在NSERC的这一应用中，我们提出了一个研究计划来填补这一空白，方法是在我们在微血管MRI方面的长期专业知识的基础上，增强我们最近开发的用于评估血管调节的变革性平台的能力-这是有史以来第一项用于扰动和测量深层组织血管调节的动态MRI技术。我们将把我们的技术推广到整个身体，解决因不同原因而面临挑战的两个剩余器官：快速跳动的心脏(挑战：运动)和骨骼肌(挑战：低灌注)。具体地说，我们将为心脏的近实时心脏MRI设计新的采集，开发数学模型来提高低灌注环境下的测量灵敏度，并集成这些功能来了解不同器官的血流是如何同步调节以维持正常血压的。总而言之，这项工作将推动微血管网络的定量生理成像的最新技术，创造在基础生理学研究、诊断医学成像以及新的组织工程和再生范例中广泛应用的新技术。此外，拟议的研究为在跨学科背景下培训核心自然科学和工程(电气工程、数学、生理学)的研究生和本科生提供了难得的机会。他们获得的科学知识和技能将使他们能够产生长期影响，并在工程学和生命科学的交汇处领导自己的倡议。