Dynamic 3HE MRI of the Lungs

肺部动态 3HE MRI

• 批准号: 7241427
• 负责人: Vinay Manjunath Pai
• 金额: $ 25.35万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7241427
• 关键词: Affect; Air; American; Anatomy; Area; Asthma; Breathing; Bronchi; Chronic; Clinical; Disease; Disease Progression; Early Diagnosis; Excision; Exhalation; Functional Imaging; Functional disorder; Gases; Goals; Health Expenditures; Helium; Human; Image; Left; Lung; Lung diseases; Magnetic Resonance Imaging; Magnetism; Maps; Methods; Monitor; Morbidity - disease rate; Morphologic artifacts; Noise; Obstruction; Phase; Phenotype; Pulmonary function tests; Resolution; Respiratory physiology; Sampling; Screening procedure; Signal Transduction; Spirometry; Techniques; Therapeutic; Three-Dimensional Image; Three-Dimensional Imaging; Trachea; base; cost; insight; mortality; novel; response; small airways disease; stem; volunteer

DESCRIPTION (provided by applicant): Small airway disease is a significant cause of morbidity and mortality. Chronic obstruction pulmonary disease (COPD) and asthma affect 40 million Americans and cost 23 billion dollars in direct health care expenditure annually. If detected early, disease progression can be slowed or halted by the removal of causative factors, and implementation of specific treatments. Means of assessing therapeutic response of the small airways are necessary to effectively apply these new treatments, but current methods of assessing lung function are limited. Clinical examination is not sensitive, is often non-specific, and identifies disease on a global but not regional basis. Pulmonary function tests (PFTs) similarly only identify global deficiencies and are insensitive to small airway disease, indeed 75% of the airways are not assessed with screening spirometry. High resolution CT can identify regional anatomic airway changes if present, but these are usually non-specific and do not necessarily reflect the degree of functional change. Many causes of airway dysfunction, such as asthma, may be occult to CT. MRI of helium-3 (3HeMRI) is a recently developed method of visualizing lung air spaces and airways. The subject inhales He that has been hyperpolarized to generate a large magnetic moment and an 3 MR image of the gas in acquired. HeMRI is exquisitely sensitive to areas of decreased air flow. However, 3 although He images have been acquired dynamically during inhalation and exhalation, no optimum method 3 has yet emerged for combining volumetric dynamic imaging with airflow quantification. The overarching goal of this proposal is to develop multiecho methods of assessing lung function using magnetic resonance imaging of inhaled hyperpolarized helium, He. SPECIFIC AIM 1: To determine the feasibility of using novel Shifted k- 3 space Imaging (SKIM) sequences for two- and three-dimensional dynamic parallel imaging. Hypothesis 1.1: Undersampled SKIM acquisitions have the same, if not higher, signal-to-noise ratios as conventional fully- sampled spin-warp acquisitions. Hypothesis 1.2: Any artifacts introduced by undersampled SKIM sequences have negligible effects on image quality. Hypothesis 1.3: Volumetric dynamic functional imaging of the lungs can be performed by combining SKIM and parallel imaging. SPECIFIC AIM 2: To determine the feasibility of using a new phase contrast approach for characterizing gas flow. Studies will be performed in flow phantoms and normal volunteers. Hypothesis 2.1: The proposed phase contrast approach can map gas flow velocities in 3He flow phantom studies with an encoding velocity (Venc) of 100 cm/s. Hypothesis 2.2: This approach can be used to map airflow velocities in the trachea, main stem bronchus and right and left bronchi in normal humans. The two aims of this proposal are essential to achieve our ultimate goal of developing a sensitive, reliable method of detecting decreased gas flow in the diseased lung. This proposal would represent the first method developed for flow and functional assessment of the lungs and as such will permit quantitative assessment of the whole lung function. Small airway disease is a significant cause of morbidity and mortality. If detected early, disease progression can be slowed or halted by the removal of causative factors, and implementation of specific treatments. However, current methods of assessing lung function are limited. Our proposal would represent the first method developed for flow and functional assessment of the lungs and will permit quantitative assessment of the whole lung function.

描述（由申请人提供）：小气道疾病是发病和死亡的重要原因。慢性阻塞性肺病 (COPD) 和哮喘影响 4000 万美国人，每年造成 230 亿美元的直接医疗保健支出。如果及早发现，可以通过消除致病因素并实施特定治疗来减缓或停止疾病进展。评估小气道治疗反应的方法对于有效应用这些新疗法是必要的，但目前评估肺功能的方法是有限的。临床检查不敏感，通常不具有特异性，并且在全球范围内而非区域范围内识别疾病。类似地，肺功能测试 (PFT) 只能识别整体缺陷，对小气道疾病不敏感，实际上 75% 的气道没有通过筛查肺活量测定法进行评估。高分辨率 CT 可以识别局部气道解剖变化（如果存在），但这些变化通常是非特异性的，不一定反映功能变化的程度。 CT 可能无法发现气道功能障碍的许多原因，例如哮喘。氦 3 MRI (3HeMRI) 是最近开发的一种可视化肺空间和气道的方法。受试者吸入已超极化的 He，产生大磁矩并获取该气体的 3 MR 图像。 HeMRI 对气流减少的区域非常敏感。然而，3 虽然 He 图像是在吸气和呼气过程中动态采集的，但尚未出现将体积动态成像与气流量化相结合的最佳方法 3。该提案的总体目标是开发使用吸入超极化氦气磁共振成像评估肺功能的多回波方法。具体目标 1：确定使用新颖的移位 k-3 空间成像 (SKIM) 序列进行二维和三维动态并行成像的可行性。假设 1.1：欠采样 SKIM 采集与传统的全采样自旋扭曲采集具有相同（如果不是更高）的信噪比。假设 1.2：欠采样 SKIM 序列引入的任何伪影对图像质量的影响都可以忽略不计。假设1.3：肺的体积动态功能成像可以通过结合SKIM和并行成像来进行。具体目标 2：确定使用新的相衬方法表征气流的可行性。研究将在流动模型和正常志愿者中进行。假设 2.1：所提出的相衬方法可以以 100 cm/s 的编码速度 (Venc) 绘制 3He 流模型研究中的气流速度。假设 2.2：这种方法可用于绘制正常人气管、主干支气管以及左右支气管的气流速度。该提案的两个目标对于实现我们的最终目标至关重要，即开发一种灵敏、可靠的方法来检测患病肺部的气流减少。该提案将代表为肺的流量和功能评估而开发的第一种方法，因此将允许对整个肺功能进行定量评估。小气道疾病是发病和死亡的重要原因。如果及早发现，可以通过消除致病因素并实施特定治疗来减缓或停止疾病进展。然而，目前评估肺功能的方法是有限的。我们的建议将代表第一种为肺的流量和功能评估而开发的方法，并将允许对整个肺功能进行定量评估。