Garrison William J, Qing Kun, He Mu, Zhao Li, Tustison Nicholas J, Patrie James T, Mata Jaime F, Shim Y Michael, Ropp Alan M, Altes Talissa A, Mugler John P, Miller G Wilson
From the Departments of Biomedical Engineering (W.J.G., J.P.M., G.W.M.), Radiology and Medical Imaging (K.Q., N.J.T., J.F.M., A.M.R., J.P.M., G.W.M.), Medicine (M.H., Y.M.S.), Public Health Sciences (J.T.P.), and Physics (G.W.M.), University of Virginia, 480 Ray C. Hunt Dr, Box 801339, Charlottesville, VA 22908; Department of Radiation Oncology, City of Hope National Medical Center, Duarte, Calif (K.Q.); Department of Biomedical Engineering, Zhejiang University, Hangzhou, China (L.Z.); and Department of Radiology, University of Missouri, Columbia, Mo (T.A.A.).
Radiol Cardiothorac Imaging. 2023 Jun 22;5(3):e220096. doi: 10.1148/ryct.220096. eCollection 2023 Jun.
To assess the effect of lung volume on measured values and repeatability of xenon 129 (Xe) gas uptake metrics in healthy volunteers and participants with chronic obstructive pulmonary disease (COPD).
This Health Insurance Portability and Accountability Act-compliant prospective study included data (March 2014-December 2015) from 49 participants (19 with COPD [mean age, 67 years ± 9 (SD)]; nine women]; 25 older healthy volunteers [mean age, 59 years ± 10; 20 women]; and five young healthy women [mean age, 23 years ± 3]). Thirty-two participants underwent repeated Xe and same-breath-hold proton MRI at residual volume plus one-third forced vital capacity (RV+FVC/3), with 29 also undergoing one examination at total lung capacity (TLC). The remaining 17 participants underwent imaging at TLC, RV+FVC/3, and residual volume (RV). Signal ratios between membrane, red blood cell (RBC), and gas-phase compartments were calculated using hierarchical iterative decomposition of water and fat with echo asymmetry and least-squares estimation (ie, IDEAL). Repeatability was assessed using coefficient of variation and intraclass correlation coefficient, and volume relationships were assessed using Spearman correlation and Wilcoxon rank sum tests.
Gas uptake metrics were repeatable at RV+FVC/3 (intraclass correlation coefficient = 0.88 for membrane/gas; 0.71 for RBC/gas, and 0.88 for RBC/membrane). Relative ratio changes were highly correlated with relative volume changes for membrane/gas ( = -0.97) and RBC/gas ( = -0.93). Membrane/gas and RBC/gas measured at RV+FVC/3 were significantly lower in the COPD group than the corresponding healthy group ( ≤ .001). However, these differences lessened upon correction for individual volume differences ( = .23 for membrane/gas; = .09 for RBC/gas).
Dissolved-phase Xe MRI-derived gas uptake metrics were repeatable but highly dependent on lung volume during measurement. Blood-Air Barrier, MRI, Chronic Obstructive Pulmonary Disease, Pulmonary Gas Exchange, Xenon © RSNA, 2023.
评估肺容积对健康志愿者和慢性阻塞性肺疾病（COPD）参与者中氙129（Xe）气体摄取指标测量值及重复性的影响。
这项符合《健康保险流通与责任法案》的前瞻性研究纳入了49名参与者的数据（2014年3月至2015年12月），其中19名患有COPD（平均年龄67岁±9岁[标准差]；9名女性）；25名老年健康志愿者（平均年龄59岁±10岁；20名女性）；以及5名年轻健康女性（平均年龄23岁±3岁）。32名参与者在残气量加三分之一用力肺活量（RV+FVC/3）时接受了重复的Xe和同屏质子MRI检查，其中29名还在肺总量（TLC）时接受了一次检查。其余17名参与者在TLC、RV+FVC/3和残气量（RV）时接受了成像检查。使用具有回波不对称性和最小二乘估计的水和脂肪分层迭代分解法（即IDEAL）计算膜、红细胞（RBC）和气相区室之间的信号比率。使用变异系数和组内相关系数评估重复性，使用Spearman相关性和Wilcoxon秩和检验评估容积关系。
在RV+FVC/3时气体摄取指标具有可重复性（膜/气的组内相关系数=0.88；RBC/气的组内相关系数=0.71，RBC/膜的组内相关系数=0.88）。膜/气和RBC/气的相对比率变化与相对容积变化高度相关（膜/气的相关系数=-0.9
