Clinical applicability of 3He and 129Xe ventilation MRI in cystic fibrosis: longitudinal follow up

Abstract

Background: Hyperpolarised gas ventilation MRI (V-MRI) is highly sensitive to early lung disease in CF. Here we report longitudinal comparisons of V-MRI measured with two different inhaled gases; helium-3 (3He) and xenon-129 (129Xe), alongside detailed lung physiology in CF. Method: 28 children and adults with CF performed both 3He and 129Xe V-MRI, LCI and FEV1 on the same day, and at follow up (FU) (mean (SD) = 14.7 (3.8) months). Ventilation defect percentage (VDP) was used to quantify lung disease on V-MRI. Results: At baseline median (IQR); FEV1 = -1.2 (-4.1;-0.7) z-score; LCI = 8.7 (7.7;13.1); 3He VDP = 8.4% (3.0;33.4); 129Xe VDP = 7.1% (2.8;30.4). Baseline 3He and 129Xe VDP significantly correlated with FEV1 and LCI (both p Conclusion: ΔVDP over time most closely relates to LCI %change. However, ΔVDP was often large in patients with clinically stable FEV1 or LCI, demonstrating that V-MRI can assess changes in lung function not assessed by clinical gold standards. 129Xe MRI is comparable to 3He for assessment of regional ventilation changes and provides a clinically scalable alternative.