Emphysema Index Based on Hyperpolarized 3He or 129Xe Diffusion MRI: Performance and Comparison with Quantitative CT and Pulmonary Function Tests

• DOI: 10.1148/radiol.2020192804
• Publication Date: 2020-08-11T14:08:27Z
• Authors: Sina Tafti; William J. Garrison; John P. Mugler; Y. Michael Shim; Talissa A. Altes; Jaime F. Mata; Eduard E. de Lange; Gordon D. Cates; Alan M. Ropp; Chengbo Wang; G. Wilson Miller
• Keywords: Rank correlation

Background Apparent diffusion coefficient (ADC) maps of inhaled hyperpolarized gases have shown promise in the characterization emphysema 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 framework which to characterize burden based on helium 3 (3He) xenon 129 (129Xe) ADC compare its diagnostic performance CT-based metrics function tests (PFTs). Materials Methods Twenty-seven mild, moderate, or severe COPD 13 age-matched healthy control subjects participated this retrospective study. Participants underwent CT multiple b value diffusion-weighted 3He 129Xe MRI examinations PFTs between August 2014 November 2017. ADC-based index was computed separately for each gas as fraction lung voxels values greater than group 99th percentile. The resulting were compared results (relative area <−950 HU) reference standard. Diagnostic included under receiver operating characteristic curve (AUC). Spearman rank correlations Wilcoxon sum performed ADC-, CT-, PFT-based metrics, intraclass correlation repeated measurements. Results Thirty-six participants evaluated (mean age, 60 years ± 6 [standard deviation]; 20 women). highly repeatable (intraclass > 0.99) strongly correlated (r = 0.86, P < .001 3He; r 0.85, 129Xe) high AUC (≥0.93; 95% confidence interval [CI]: 1.00). indices also percentage predicted diffusing capacity carbon monoxide −0.81, −0.80, residual volume divided by total 0.65, 0.61, 129Xe). Conclusion Emphysema provides measure burden, independent value, similar metrics. © RSNA, 2020 Online supplemental material is available article. See editorial Schiebler Fain issue.