Lung Volume Dependence and Repeatability of Hyperpolarized 129Xe MRI Gas Uptake Metrics in Healthy Volunteers and Participants with COPD

William J Garrison; Kun Qing; Mu He; Li Zhao; Nicholas J Tustison; James T Patrie; Jaime F Mata; Y Michael Shim; Alan M Ropp; Talissa A Altes; John P Mugler 3rd; G Wilson Miller

doi:10.1148/ryct.220096

Lung Volume Dependence and Repeatability of Hyperpolarized ¹²⁹Xe MRI Gas Uptake Metrics in Healthy Volunteers and Participants with COPD

Radiol Cardiothorac Imaging. 2023 Jun 22;5(3):e220096. doi: 10.1148/ryct.220096. eCollection 2023 Jun.

Authors

Affiliation

¹ 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.).

Abstract

Purpose: To assess the effect of lung volume on measured values and repeatability of xenon 129 (¹²⁹Xe) gas uptake metrics in healthy volunteers and participants with chronic obstructive pulmonary disease (COPD).

Materials and methods: 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 ¹²⁹Xe 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.

Results: 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 (r = -0.97) and RBC/gas (r = -0.93). Membrane/gas and RBC/gas measured at RV+FVC/3 were significantly lower in the COPD group than the corresponding healthy group (P ≤ .001). However, these differences lessened upon correction for individual volume differences (P = .23 for membrane/gas; P = .09 for RBC/gas).

Conclusion: Dissolved-phase ¹²⁹Xe MRI-derived gas uptake metrics were repeatable but highly dependent on lung volume during measurement.Keywords: Blood-Air Barrier, MRI, Chronic Obstructive Pulmonary Disease, Pulmonary Gas Exchange, Xenon Supplemental material is available for this article © RSNA, 2023.

Keywords: Blood-Air Barrier; Chronic Obstructive Pulmonary Disease; MRI; Pulmonary Gas Exchange; Xenon.

Grants and funding

R01 HL132177/HL/NHLBI NIH HHS/United States