129Xe MRI radiofrequency coil for in vivo measurements of airways and alveoli to generate novel lung biomechanical models

129Xe MRI 射频线圈用于气道和肺泡的体内测量，以生成新型肺生物力学模型

• 批准号: RTI-2017-00240
• 负责人: Parraga, Grace
• 金额: $ 10.93万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=616606
• 关键词: 129Xe; MRI; radiofrequency; coil; vivo

Our current understanding of lung microstructure and biomechanics derives mainly from stereological and micro-CT investigations of excised tissue from cadavers or explanted lungs. However, neither histology, nor micro-CT may be considered for large-scale studies of normal lung physiology because they rely on excised samples which is highly invasive and carries some risk. In silico mathematical lung models have also been constructed as a system with airways (resistors) and alveoli (capacitors) using pressure and flow measurements made at the mouth or catheters implanted at the trachea. These global lung measurements ignore very recent work that showed that the normal healthy lung is regionally heterogenous and this heterogeneity is enhanced in lung disease. In other words, there are non-stochastic differences and abnormalities that must be considered. Unfortunately, a lack of regional lung structural and functional information has made it difficult to incorporate regional dependencies into lung micromechanical models, and made it impossible to validate them. To directly address this decades-old problem, Dr Parraga’s lab and her collaborators are developing new ways to incorporate in vivo lung imaging measurements into existing models of lung micromechanics, to develop new micromechanical models and to test and validate them. To accomplish this important goal, we require a state-of-the art radiofrequency (RF) MRI coil for high spatial resolution 129Xe inhaled-gas ventilation and diffusion-weighted measurements. This critically-needed infrastructure will drive the development and validation of novel lung imaging biomarkers the team will use to generate models of lung development and biomechanics. Daily access to a similar (and now catastrophically failed) radiofrequency coil has already played a critical role in our local and transnational research program. The new radiofrequency coil, once commissioned, will accelerate: 1) improved spatial and temporal resolution of pulmonary MRI using novel pulse sequences, 2) the acquisition of alveolar and airway dimensions in different lung states and conditions, and, 3) the incorporation and validation of regional imaging measurements into computational models. Due to the high throughput nature of our collaborative research, a custom-designed multichannel 129Xe MRI coil is required. Conversely, the lack of such equipment would significantly compromise our innovative basic research that aims to generate novel lung micromechanical models of normal and regenerated lung tissue in vivo. Moreover, this infrastructure will accelerate the training of highly qualified personnel for academia and the private sector in medical imaging, MR physics, lung tissue regeneration, molecular modelling and computer science including graduate students and postdoctoral fellows at Western, McMaster and Dalhousie Universities.

我们目前对肺微结构和生物力学的了解主要来源于对身体或移植肺切除组织的体视学和显微CT研究。然而，无论是组织学，还是微型CT，都不能被考虑用于正常肺生理的大规模研究，因为它们依赖于切除的样本，这是高度侵入性的，并带有一定的风险。在计算机数学中，肺模型也被构建为具有呼吸道(电阻器)和肺泡(电容器)的系统，使用在口腔或在气管植入的导管进行的压力和流量测量。这些全球肺测量忽略了最近的工作，即正常健康肺在区域上是异质性的，这种异质性在肺部疾病中得到加强。换句话说，必须考虑非随机差异和异常。不幸的是，由于缺乏区域肺结构和功能信息，使得将区域相关性纳入肺微机械模型变得困难，并且无法对其进行验证。 为了直接解决这个几十年来的问题，帕拉加博士的实验室和她的合作者正在开发新的方法，将活体肺成像测量纳入现有的肺微观力学模型，开发新的微机械模型，并对其进行测试和验证。为了实现这一重要目标，我们需要最先进的射频(RF)磁共振线圈，用于高空间分辨率的129Xe吸入气体通风和扩散加权测量。这一急需的基础设施将推动开发和验证新的肺成像生物标记物，该团队将使用这些标记物来生成肺发育和生物力学模型。每天都能接触到一个类似的射频线圈(现在已经灾难性地失败了)，这已经在我们的本地和跨国研究计划中发挥了关键作用。一旦投入使用，新的射频线圈将加速：1)使用新的脉冲序列提高肺部MRI的空间和时间分辨率；2)获取不同肺部状态和条件下的肺泡和呼吸道尺寸；3)将区域成像测量纳入计算模型并进行验证。由于我们合作研究的高通量性质，需要定制设计的多通道129Xe磁共振线圈。相反，缺乏这样的设备将极大地损害我们的创新基础研究，该研究旨在产生体内正常和再生肺组织的新的肺微机械模型。此外，这一基础设施将加快为学术界和私营部门培训医学成像、磁共振物理学、肺组织再生、分子建模和计算机科学方面的高素质人才，包括西方大学、麦克马斯特大学和达尔豪西大学的研究生和博士后研究员。