Inhaled gas and Ultra-short/zero-echo time MRI of pulmonary airways and airspaces for modelling the morphometry and biomechanical properties of pulmonary parenchyma and airways

吸入气体和肺气道和空腔的超短/零回波时间 MRI，用于模拟肺实质和气道的形态测量和生物力学特性

• 批准号: RGPIN-2016-04760
• 负责人: Parraga, Grace
• 金额: $ 4.37万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=690945
• 关键词: Inhaled; gas; Ultra; short; zero

Recent advances in lung imaging using conventional and inhaled gas magnetic resonance imaging (MRI) have accelerated the acquisition of high-resolution, three-dimensional non-invasive in vivo lung measurements that until now have never been possible. ******Our current understanding of lung tissue architecture and morphology derive from stereiological investigations of excised tissue, typically from cadavers or explanted lungs from patients undergoing transplant. Such measurements are typically focused on diseased lung and may be biased because of the methods used to generate these samples. Another approach involves micro-CT of ex vivo tissue samples and this provides the advantage of 3-dimensional sampling. Unfortunately, neither histology, nor micro-CT of excised samples can be used for large studies of normal physiology and the developing lung because they rely on the excised samples which is highly invasive and carries some risk. Another approach is to model the lung components as a regionally uniform system of airways (resistors) and airspaces (capacitors). Such lung micromechanical models have been derived mainly using pressure and flow measurements at the mouth or using retrograde catheters implanted at the end of the trachea of excised lungs. Despite the importance of these approaches and the huge body of work that provide their strong foundation, it has not been possible to incorporate regional functional lung information to interrogate these models or to assist in their development. This is a critical limitation because it is well understood that the lung is in fact, a regionally heterogeneous organ. ******Therefore there has been, for decades, a significant unmet need for lung regional morphological information derived from physiologically-relevant in vivo measurements for inclusion in mathematical models of lung micromechanics. To directly address this decades-old problem, we propose to develop new ways to generate and incorporate in vivo lung imaging measurements of airway and airspace structure into existing models of lung growth, development and micromechanics and to develop new models and test these using regional imaging information. ******Therefore, in this proposal we will develop new ways to use lung imaging measurements to generate models of lung development and biomechanics. Over 5 years, we will: 1) improve spatial and temporal resolution of pulmonary MRI using novel pulse sequences, 2) derive alveolar and 3) airway dimensions in different lung states and conditions, and, 4) incorporate and validate regional imaging measurements into computational models. This research provides a way to test and validate imaging measurements for the generation of novel micromechanical models of the lung and highly qualified personnel for academia and the private sector in medical imaging, MR pulse sequence development, lung tissue generation, molecular modelling and computer science. **

使用传统和吸入气体磁共振成像 (MRI) 的肺部成像的最新进展加速了高分辨率、三维非侵入性体内肺部测量的获取，这是迄今为止从未实现的。 ******我们目前对肺组织结构和形态的理解源自对切除组织的体视学研究，这些组织通常来自尸体或接受移植的患者的外植肺。 此类测量通常集中于患病肺部，并且由于用于生成这些样本的方法而可能存在偏差。 另一种方法涉及离体组织样本的显微 CT，这提供了 3 维采样的优势。 不幸的是，组织学和切除样本的显微 CT 都不能用于正常生理学和发育中肺部的大型研究，因为它们依赖于切除样本，而切除样本具有高度侵入性并带有一定的风险。 另一种方法是将肺组件建模为气道（电阻器）和空域（电容器）的区域统一系统。 这种肺微机械模型主要使用口腔的压力和流量测量或使用植入在切除肺的气管末端的逆行导管来推导。 尽管这些方法很重要，并且大量的工作为其提供了坚实的基础，但仍不可能合并区域功能性肺信息来询问这些模型或协助其开发。这是一个关键的限制，因为众所周知，肺实际上是一个区域异质的器官。 ******因此，几十年来，对于来自生理相关体内测量的肺区域形态信息的需求一直未被满足，这些信息包含在肺微力学的数学模型中。 为了直接解决这个已有数十年历史的问题，我们建议开发新方法来生成气道和空域结构的体内肺部成像测量并将其纳入现有的肺部生长、发育和微力学模型中，并开发新模型并使用区域成像来测试这些模型信息。 ******因此，在本提案中，我们将开发新的方法来使用肺部成像测量来生成肺部发育和生物力学模型。 在 5 年内，我们将：1) 使用新型脉冲序列提高肺部 MRI 的空间和时间分辨率，2) 导出肺泡和 3) 不同肺部状态和条件下的气道尺寸，4) 将区域成像测量纳入计算并进行验证模型。这项研究提供了一种测试和验证成像测量的方法，以生成新型肺部微机械模型，并为学术界和私营部门提供医学成像、MR脉冲序列开发、肺组织生成、分子建模和计算机科学方面的高素质人员。 **