Emphysema Index Based on Hyperpolarized 3He or 129Xe Diffusion MRI: Performance and Comparison with Quantitative CT and Pulmonary Function Tests
Emphysema Index Based on Hyperpolarized 3He or 129Xe Diffusion MRI: Performance and Comparison with Quantitative CT and Pulmonary Function Tests
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DOI：
10.1148/radiol.2020192804
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发表时间：
2020-10-01
期刊：
影响因子：
19.7
通讯作者：
Miller, G. Wilson
中科院分区：
文献类型：
--
作者：
Tafti, Sina;Garrison, William J.;Miller, G. Wilson
背景资料：吸入超极化气体的表观扩散系数（ADC）图在慢性阻塞性肺疾病（COPD）患者肺气肿的表征中显示出希望，但尚未建立超出平均值和标准差的易于解释的定量度量。目的：介绍一种基于超极化氦3（He-3）和氙129（Xe-129）表征肺气肿负荷的定量框架ADC地图和比较其诊断性能与CT为基础的肺气肿指标和肺功能测试（PFTs）。材料和方法：27例轻度，中度或重度COPD患者和13名年龄匹配的健康对照者参加了这项回顾性研究。参与者在2014年8月至2017年11月期间接受了CT和多个B值扩散加权He-3和MRI检查以及标准PFT。分别计算每种气体和B值的基于ADC的肺气肿指数，b值是ADC值大于健康组第99百分位数的肺体素的分数。将所得值与定量CT结果进行比较（相对肺面积0.93; 95%置信区间[CI]：0.85，1.00）。ADC肺气肿指数也与预测的一氧化碳肺弥散量百分比相关（He-3的r = 20.81，P < .001; Xe-129的r = 20.80，P < .001）和预测残余肺容量除以总肺容量的百分比结论：基于超极化氦3或氙129扩散MRI的肺气肿指数提供了肺气肿负荷的可重复测量，与气体或B值无关，具有与定量CT或肺功能指标相似的诊断性能。(C)RSNA，2020年
Background: Apparent diffusion coefficient (ADC) maps of inhaled hyperpolarized gases have shown promise in the characterization of emphysema in patients with chronic obstructive pulmonary disease (COPD), yet an easily interpreted quantitative metric beyond mean and standard deviation has not been established.Purpose: To introduce a quantitative framework with which to characterize emphysema burden based on hyperpolarized helium 3 (He-3) and xenon 129 (Xe-129) ADC maps and compare its diagnostic performance with CT-based emphysema metrics and pulmonary function tests (PFTs).Materials and Methods: Twenty-seven patients with mild, moderate, or severe COPD and 13 age-matched healthy control subjects participated in this retrospective study. Participants underwent CT and multiple b value diffusion-weighted He-3 and Xe-129 MRI examinations and standard PFTs between August 2014 and November 2017. ADC-based emphysema index was computed separately for each gas and b value as the fraction of lung voxels with ADC values greater than in the healthy group 99th percentile. The resulting values were compared with quantitative CT results (relative lung area 0.93; 95% confidence interval [CI]: 0.85, 1.00). ADC emphysema indices were also correlated with percentage of predicted diffusing capacity of lung for carbon monoxide (r = 20.81, P < .001 for He-3; r = 20.80, P < .001 for Xe-129) and percentage of predicted residual lung volume divided by total lung capacity (r = 0.65, P < .001 for He-3; r = 0.61, P < .001 for Xe-129).Conclusion: Emphysema index based on hyperpolarized helium 3 or xenon 129 diffusion MRI provides a repeatable measure of emphysema burden, independent of gas or b value, with similar diagnostic performance as quantitative CT or pulmonary function metrics. (C) RSNA, 2020