Spatial-Temporal Dynamics of Blood Flow in the Normal Human Lung

描述（由申请人提供）：这些研究的总体长期目标是了解控制肺血流的机制，以及该控制如何导致健康和疾病中的气体交换缺陷或优化。具体目标是使用一种新的MRI技术来量化正常人肺中血流的空间和时间动态。在许多生理系统中的时间异质性已被发现是健康功能的标志，但对人肺中血流的时间动力学知之甚少，因为用于测量时间异质性的适当工具还不可用。最近，我们开发了一种非侵入性MRI技术，该技术提供了定量测量肺血流的空间分辨率<1 cm 3，时间分辨率约为10 s，使我们能够首次检查人肺的时空异质性。特定目的旨在系统地探索时空异质性的正常谱，测试：1）健康受试者吸入气体（O2和CO2）改变的影响; 2）运动的影响; 3）衰老的影响;以及4）易患高原肺水肿受试者肺部O2和CO2改变的影响。这将是第一个系统的，定量的研究人类受试者的肺血流的空间和时间动力学，并将奠定基础，应用这些方法在早期检测和表征疾病。 公共卫生相关性：肺部血液的氧合取决于通气和血流的紧密匹配：新鲜气体和血流需要在同一时间和同一地点。我们已经开发出一种新的成像技术，用于测量人体肺中血流的分布，不仅在空间上，而且随着时间的推移，测量之前是不可能的。在这项工作中，我们将探索血流的正常动力学，作为应用这些方法来识别和更好地理解疾病的潜在机制的基础。

DESCRIPTION (provided by applicant): The overall long-term goal of these studies is to understand the mechanisms by which pulmonary blood flow is controlled, and how that control contributes to gas exchange defects or optimization in health and disease. The specific goal is to use a novel MRI technique to quantify the spatial and temporal dynamics of blood flow in the normal human lung. Temporal heterogeneity in a number of physiological systems has been found to be a mark of healthy function, yet little is known about the temporal dynamics of blood flow in the human lung because the appropriate tools for measuring temporal heterogeneity have not been available. Recently we developed a noninvasive MRI technique that provides quantitative measurements of pulmonary blood flow with a spatial resolution of <1 cm3 and a temporal resolution of ~10 s in the human lung, permitting us to examine spatial-temporal heterogeneity in the human lung for the first time. The Specific Aims are designed to systematically explore the normal spectrum of spatial-temporal heterogeneity, testing: 1) the effects of altered inspired gas (O2 and CO2) in healthy subjects; 2) the effects of exercise; 3) the effects of ageing; and 4) the effects of altered O2 and CO2 in the lungs of subjects susceptible to high altitude pulmonary edema. This will be the first systematic, quantitative study of the spatial and temporal dynamics of pulmonary blood flow in human subjects, and will lay a foundation for applying these methods in the early detection and characterization of disease. PUBLIC HEALTH RELEVANCE: Oxygenation of the blood in the lungs depends on a close matching of ventilation and blood flow: fresh gas and blood flow need to be at the same place and at the same time. We have developed a novel imaging technique for measuring the distribution of blood flow in the human lung not only spatially, but also over time, a measurement that has not been possible before. In this work we will explore the normal dynamics of blood flow as a foundation for applying these methods to identify, and to better understand, the underlying mechanisms of disease.