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）：小气道疾病是发病率和死亡率的重要原因。慢性阻塞肺疾病（COPD）和哮喘影响4000万美国人，每年耗资230亿美元的直接医疗保健支出。如果早期检测到，疾病进展可以通过去除因素和实施特定治疗方法来减慢或停止。为了有效地应用这些新疗法，需要评估小气道的治疗反应的手段，但是当前评估肺功能的方法是有限的。临床检查不敏感，通常是非特异性的，并且在全球但不是区域基础上鉴定疾病。肺功能测试（PFT）类似地仅鉴定出全球缺陷，对小气道疾病不敏感，实际上，有75％的气道未通过筛查肺活量测定来评估。高分辨率CT如果存在，可以识别区域解剖通风道的变化，但通常是非特异性的，不一定反映了功能变化的程度。气道功能障碍（例如哮喘）的许多原因可能被神秘为CT。氦3（3hemri）的MRI是一种可视化肺空间和气道的最近开发的方法。被超极化的受试者吸入以产生较大的磁矩和3m的3 mr图像。 HEMRI对降低空气流动的区域非常敏感。然而，尽管在吸入和呼气过程中，尽管他的图像是动态获取的，但尚未出现最佳方法3用于将体积动态成像与气流定量相结合。该提案的总体目标是开发使用吸入超极化氦气的磁共振成像评估肺功能的多回声方法。特定目标1：确定使用新型移动的K-3空间成像（SKIM）序列进行二维动态平行成像的可行性。假设1.1：不足采样的略读性采集具有与常规全面采样的自旋波波采集相同的（即使不是更高）的信噪比。假设1.2：未采样的脱脂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合并脱脂和并行成像来进行。具体目标2：确定使用新相对比方法来表征气流的可行性。研究将在流幻象和正常志愿者中进行。假设2.1：所提出的相比方法可以在3HE流幻像研究中绘制气流速度，其编码速度（Venc）为100 cm/s。假设2.2：这种方法可用于绘制正常人中的气管，主茎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开发一种敏感，可靠的方法来检测患病肺中气体流量减少的最终目标至关重要。该建议将代表用于肺部流量和功能评估的第一种方法，因此将允许对整个肺功能进行定量评估。小气道疾病是发病率和死亡率的重要原因。如果早期检测到，疾病进展可以通过去除因素和实施特定治疗方法来减慢或停止。但是，当前评估肺功能的方法是有限的。我们的建议将代表用于对肺的流量和功能评估开发的第一种方法，并将允许对整个肺功能进行定量评估。