Abstract
Background: MRI of hyperpolarized 129Xenon (HP 129Xe) is increasingly utilized for investigating pulmonary function. The solubility of HP 129Xe in lung tissue, blood plasma (Barrier), and red blood cells (RBC), with unique chemical shifts, enables spectroscopic imaging of potential imaging biomarkers of gas exchange and microstructural pulmonary physiology. Purpose: To quantify global average and regional repeatability of Barrier:gas, RBC:gas, and RBC:Barrier ratios derived from dissolved-phase 129Xe imaging and their dependence on intervisit changes in lung inflation volume. Study Type: Prospective. Population: Fourteen healthy volunteers. One subject was unable to complete the study resulting in 13 subjects for analysis (eight female, five male, ages 24–69, 53.8 ± 13.9). Field Strength: 1.5T. Assessment: Subjects were imaged using a 3D radial 1-point Dixon method to separate Barrier and RBC component signals, at two different timepoints, with ~1 month between visits. RBC:Gas, Barrier:Gas, and RBC:Barrier measures were compared across time and with pulmonary function tests (PFTs). Statistical Tests: Repeatablilty was quantified using Bland–Altman plots, coefficient of repeatability, coefficient of variation (CV), and intraclass correlation coefficients (ICCs). Dependence of imaging measures on PFTs and lung volume was evaluated using Spearman and Pearson correlation coefficients, respectively. Statistical significance was determined by F-test for intraclass correlations, and t-test for Spearman correlations and regression. Results: Mean RBC:Gas, Barrier:Gas, and RBC:Barrier had CVs of 19.2%, 20.0%, and 11.5%, respectively, and had significant ICCs, equal to 0.78, 0.79, and 0.92, respectively. Intervisit differences in RBC:Barrier were significantly correlated with intervisit differences in DLCO (r = 0.93, P = 0.007). Significant correlations with intervisit lung volume differences and intervisit differences in mean RBC:Gas (r = –0.73, P = 0.005) and Barrier:Gas (r = –0.69, P = 0.009) were found. Data Conclusion: Three commonly used 129Xe MRI-based measures of gas-exchange show good repeatability, particularly the Barrier:RBC ratio, which did not depend on lung inflation volume and was strongly associated with intervisit changes in DLCO. Level of Evidence: 1. Technical Efficacy: Stage 1. J. Magn. Reson. Imaging 2019;50:1182–1190.
Original language | English (US) |
---|---|
Pages (from-to) | 1182-1190 |
Number of pages | 9 |
Journal | Journal of Magnetic Resonance Imaging |
Volume | 50 |
Issue number | 4 |
DOIs | |
State | Published - Oct 1 2019 |
Bibliographical note
Funding Information:Contract grant sponsor: NIH/NHLBI; Contract grant number: R01 HL126771; Contract grant sponsor: NIH/NCRR; Contract grant number: 1 S10 OD016394; Contract grant sponsor: NIH NCATS; Contract grant number: UL1 TR000427 (to UW ICTR). We thank the study coordinators and technologists who contributed to this work, including Haley Cilliers RT, Jan Yakey RN, CCRC, Janelle Fuller RT, Molly Ellertson RN, Sara John RT, and others.
Publisher Copyright:
© 2019 International Society for Magnetic Resonance in Medicine