Redistribution of inhaled hyperpolarized 3He gas during breath-hold differs by asthma severity
Redistribution of inhaled hyperpolarized 3He gas during breath-hold differs by asthma severity
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DOI：
10.1152/japplphysiol.00197.2015
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发表时间：
2016-03-01
影响因子：
3.3
通讯作者：
Fain, Sean B.
中科院分区：
文献类型：
--
作者：
Hahn, Andrew D.;Cadman, Robert V.;Fain, Sean B.
这项工作的目的是量化的呼吸加权信号在哮喘受试者在屏气期间使用高时空分辨率的超极化（HP）He-3 MRI的肺中的再分布。采用HP He-3 MRI获得39例健康/非疾病（n = 14）、轻中度哮喘（n = 17）或重度哮喘（n = 8）受试者屏气期间肺通气的时间分辨容积图像。将信号标准化为标准肺体积，以便将所有39名受试者的肺内体素作为一个组进行分析，以增加统计功效，并将体素半自动分类为5种通气水平类别之一（从缺陷到高信号）。使用ANOVA比较了5种通气类别中每一种的吸气末通气分布和平均信号变化的时间速率。假设信号变化的时间速率代表潜在的气体再分布过程，可能受到疾病的影响。我们发现，轻中度哮喘患者的信号变化率最大，尽管重度哮喘患者的吸气末通气异质性最大。观察到的结果支持存在局部差异的气道阻力与不同的阻塞模式，在肺中的重度与轻度至中度哮喘受试者。
The purpose of this work was to quantify the redistribution of ventilation-weighted signal in the lungs of asthmatic subjects during a breath-hold using high temporal-spatial resolution hyperpolarized (HP) He-3 MRI. HP He-3 MRI was used to obtain time-resolved, volumetric images of lung ventilation during breath-hold in 39 human subjects classified as either healthy/nondiseased (n = 14), mild-tomoderate asthmatic (n = 17), or severely asthmatic (n = 8). Signals were normalized to a standard lung volume, so that voxels within the lung from all 39 subjects could be analyzed as a group to increase statistical power and enable semiautomated classification of voxels into 1 of 5 ventilation level categories (ranging from defect to hyperintense). End-inspiratory ventilation distribution and temporal rates of mean signal change for each of the five ventilation categories were compared using ANOVA. Time rates of signal change were hypothesized to represent underlying gas redistribution processes, potentially influenced by disease. We found that mild-to-moderate asthmatic subjects showed the greatest rate of signal change, even though those with severe asthma had the greatest end-inspiration ventilation heterogeneity. The observed results support the existence of local differences in airway resistances associated with the different obstructive patterns in the lungs for severe vs. mild-to-moderate asthmatic subjects.