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: 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=615286
• 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.

使用常规和吸入气体磁共振成像（MRI）的肺成像的最新进展已加速了获得高分辨率，三维非侵入性体内肺测量的获取，直到现在到目前为止一直无法使用。 我们目前对肺组织结构和形态学的理解来自对切除的组织的立体研究，通常来自尸体或接受移植患者的肺部肺部。此类测量通常集中在患病的肺部，并且由于用于生成这些样品的方法而可能存在偏差。另一种方法涉及离体组织样品的微CT，这提供了3维采样的优势。不幸的是，切除的样品的组织学和微分组都不能用于正常生理学和发育中的肺部大型研究，因为它们依赖于高度侵入性并带有一些风险的切除样品。另一种方法是将肺部成分建模为一个区域均匀的气道系统（电阻）和空域（电容器）。这种肺微机械模型主要是使用口腔处的压力和流量测量或使用在切除肺部气管末端植入的逆行导管得出的。尽管这些方法的重要性及其提供了巨大基础的大量工作，但不可能将区域功能性肺部信息纳入询问这些模型或协助其发展。这是一个关键的局限性，因为众所周知，肺实际上是一个区域异质器官。 因此，数十年来一直存在着对肺部区域形态学信息的巨大需求，这些信息是从生理上与体内相关的体内测量中得出的，以纳入肺微力学的数学模型。为了直接解决这个数十年历史的问题，我们建议开发新的方法来生成和纳入气道和空域结构中的体内肺成像测量结果中，以纳入现有的肺部生长，开发和微力学模型，并开发新模型并使用区域成像进行测试信息。 因此，在此提案中，我们将开发新的方法来使用肺成像测量来生成肺发育和生物力学模型。在5年的时间内，我们将：1）使用新型脉冲序列，2）在不同的肺状态和条件下提出肺泡尺寸，以及4）将肺泡尺寸改善肺动脉MRI的空间和时间分辨率，4）将和验证区域成像测量纳入计算型号。这项研究提供了一种方法来测试和验证成像测量值，以生成学术界的新型微型机械模型和高素质的人员，以及医学成像中的私营部门，MR脉冲序列发展，肺组织产生，分子建模和计算机科学。