Development of Airway Imaging Using HP 3He MRI

使用 HP 3He MRI 开发气道成像

• 批准号: 7064809
• 负责人: MITCHELL S ALBERT
• 金额: $ 1.81万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-15 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7064809
• 关键词: asthma; bioimaging /biomedical imaging; biomedical equipment development; clinical research; computed axial tomography; helium; human subject; lung; lung imaging /visualization /scanning; magnetic resonance imaging; methacholine; patient oriented research; pulmonary respiration; respiratory function

DESCRIPTION (provided by applicant): Historically, lung ventilation has been difficult to image. Although other imaging modalities provide insight into airway anatomy and reactivity (e.g., MDCT) or ventilation (e.g., dynamic CT, radio-nuclear imaging including PET), to date only CT can combine a view of both structure and function. However, the associated radiation, particularly in children, is driving a search for alternative methodologies. The unique work of our group forms an essential part of this effort to limit radiation exposure while improving our ability to depict the structural and functional mechanics of lung ventilation. To this end, we propose to establish HP 3He MRI as a clinically safe imaging modality that enables us to visualize ventilation function and airway constriction. However, a number of challenges regarding our ability to quantitate structure and function using this modality remain. As imaging moves into the arena of quantitative regional functional assessment of the lung, our drive to establish HP 3He MRI as an acceptable alternative or as a complimentary modality to current CT technologies could not be better timed. We further propose to combine HP 3He MRI with sensitive measures of airway function to determine the specific constriction conditions associated with asthma. We will test the hypothesis that HP 3He MRI provides similar airway resolution to MDCT, as well as additional functional ventilation information. This will entail 1) optimizing our current dynamic HP 3He MRI methodology to obtain high-resolution images of the airways; 2) developing both airway and ventilation quantification methods for the HP 3He MR images; 3) calculating HP 3He MRI airway diameters for both healthy and asthmatic subjects; and 4) comparing these measurements to those obtained from MDCT lung imaging and 3D airway reconstruction. We will then test the hypothesis that airway constriction in asthmatics is highly heterogeneous and is primarily characterized by airway closures in the small airways, and that airway dilation during a deep inspiration is diminished with increased asthma severity. Specifically, we will systematically investigate the distinctive nature of pulmonary airway narrowing and expansion in healthy versus asthmatic lungs both pre- and post-methacholine challenge using hyperpolarized (HP) 3He MRI and, as an overarching objective, discern its implication for the diagnosis and treatment of asthma. We will also investigate the frequency dependence of dynamic lung resistance and elastance and calculate the airway resistance during both normal breathing and a deep inspiration. Finally, we will correlate structural defects in airway constriction and ventilation with functional defects. At a minimum, successful proof-of-concept will establish HP 3He MRI as an important complement to MDCT. Indeed, by offering both functional information as well as a degree of airway resolution comparable to MDCT, all without the need for radiation exposure, we are confident the use HP 3He MRI will ultimately lead to improved asthma management across the spectrum--from diagnosis to treatment to enhanced quality of life.

描述（由申请人提供）： 从历史上看，肺通气一直难以成像。尽管其他成像模态提供了对气道解剖结构和反应性的洞察（例如，MDCT）或通气（例如，动态CT、包括PET的放射性核成像），迄今为止，只有CT能够将结构和功能的视图联合收割机结合起来。然而，相关的辐射，特别是对儿童的辐射，正在推动寻找替代方法。我们团队的独特工作是限制辐射暴露的重要组成部分，同时提高了我们描绘肺通气结构和功能机制的能力。为此，我们建议建立HP 3 He MRI作为一种临床安全的成像方式，使我们能够可视化通气功能和气道收缩。然而，一些挑战，我们的能力，定量的结构和功能，使用这种方式仍然存在。随着成像技术进入肺的定量区域功能评估的竞技场，我们将HP 3 He MRI确立为可接受的替代方案或作为当前CT技术的补充方式的努力可谓恰逢其时。 我们进一步建议将联合收割机HP 3 He MRI与气道功能的敏感测量相结合，以确定与哮喘相关的特定收缩条件。我们将检验HP 3 He MRI提供与MDCT相似的气道分辨率以及额外功能性通气信息的假设。这将需要1）优化我们目前的动态HP 3 He MRI方法，以获得气道的高分辨率图像; 2）为HP 3 He MR图像开发气道和通气定量方法; 3）计算健康和哮喘受试者的HP 3 He MRI气道直径; 4）将这些测量结果与MDCT肺成像和3D气道重建获得的测量结果进行比较。然后，我们将检验以下假设：哮喘患者的气道收缩是高度异质性的，主要特征是小气道的气道闭合，深吸气时的气道扩张随着哮喘严重程度的增加而减少。 具体来说，我们将系统地研究肺气道狭窄和扩张的独特性质，在健康与哮喘肺前和后乙酰甲胆碱的挑战，使用超极化（HP）3 He MRI，并作为一个首要目标，辨别其含义的诊断和治疗哮喘。我们还将研究动态肺阻力和弹性的频率依赖性，并计算正常呼吸和深吸气期间的气道阻力。最后，我们将把气道收缩和通气的结构缺陷与功能缺陷联系起来。 至少，成功的概念验证将使HP 3 He MRI成为MDCT的重要补充。事实上，通过提供功能信息以及与MDCT相当的气道分辨率，所有这些都不需要辐射暴露，我们相信HP 3 He MRI的使用最终将改善整个范围内的哮喘管理-从诊断到治疗再到提高生活质量。