Pulmonary Gas Flow Measurement by 3He MRI

描述（由申请人提供）： 广泛的长期目标：开发使用超极化3He MRI测量局部肺气体流量和体积的方法。健康相关性：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局的而不是局部的，要么是揭示肺部解剖结构而不是功能，因此通常使用有限，特别是在小气道疾病的评估中。该项目将开发一种潜在的更敏感的评估局部肺功能的方法。具体目标：1）开发动态图像配准的方法，以将在呼吸周期中的不同点处采集的图像投影到单个参考帧上。2)使基于指示剂稀释理论的算法适用于气体流量的测量。研究设计：1）将使用SPAMM标记的质子MRI和肺活量测定的组合来测量呼吸周期期间的肺位置。然后将应用仿射变换以将肺部位置映射到参考图像帧。2)在吸入超极化3He期间进行动态螺旋3He MRI。标准指示剂稀释算法将应用于动态3He图像，以逐像素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.