Pulmonary Gas Flow Measurement by 3He MRI

描述(由申请人提供)： 远期目标：发展使用超极化3He MRI测量局部肺气体流量和容量的方法。与健康相关：小气道疾病是相当大的发病率和死亡率的原因。目前评估肺部疾病的方法要么是全球性的，而不是区域性的，要么是揭示了肺的解剖结构，而不是功能，因此往往用途有限，特别是在评估小气道疾病方面。该项目将开发一种潜在的更敏感的方法来评估区域肺功能。具体目标：1)发展动态图像配准方法，将呼吸周期不同点采集的图像投影到单个参考系上。2)将基于指示剂稀释理论的算法应用于气体流量的测量。研究设计：1)SPAM标记质子磁共振和肺活量测定相结合的方法，用于测量呼吸周期中的肺位置。然后应用仿射变换将肺部位置映射到参考图像帧。2)超极化3He吸入过程中进行动态螺旋3He磁共振扫描。标准指示剂稀释算法将被应用于动态3He图像，以逐个像素的基础上计算气体流量和体积。

DESCRIPTION (provided by applicant): Broad long-term objectives: To develop methods of measuring regional pulmonary gas flow and volume using hyperpolarized 3He MRI. Health Relatedness: Small airway disease is responsible for considerable morbidity and mortality. Current methods of assessing lung disease are either global rather than regional or reveal lung anatomy rather than function and are therefore often of limited use, particularly in assessment of small airway disease. This project will develop a potentially much more sensitive method of assessing regional lung function. Specific Aims: 1) To develop methods of dynamic image co-registration to project images acquired at different points in the breathing cycle onto a single reference frame. 2) To adapt algorithms based on indicator dilution theory to the measurement of gas flow. Research Design: 1) A combination SPAMM tagged proton MRI and spirometry will be used to measure lung position during the respiratory cycle. Affine transformations will then be applied to map lung positions to a reference image frame. 2) Dynamic spiral 3He MRI will be performed during inhalation of hyperpolarized 3He. Standard indicator dilution algorithms will be applied to the dynamic 3He images to calculate gas flow and volume on a pixel by pixel basis.