<scp><sup>129</sup>Xe</scp> and Free‐Breathing <scp><sup>1</sup>H</scp> Ventilation <scp>MRI</scp> in Patients With Cystic Fibrosis: A Dual‐Center Study
Helen Marshall, Andreas Voskrebenzev, Laurie Smith, Alberto Biancardi, Agilo Luitger Kern, Guilhem Collier, Piotr A. Wielopolski, Pierluigi Ciet, Harm A.W.M. Tiddens, Jens Vogel‐Claussen, Jim M. Wild
Abstract
Background Free‐breathing 1 H ventilation MRI shows promise but only single‐center validation has yet been performed against methods which directly image lung ventilation in patients with cystic fibrosis (CF). Purpose To investigate the relationship between 129 Xe and 1 H ventilation images using data acquired at two centers. Study type Sequence comparison. Population Center 1; 24 patients with CF (12 female) aged 9–47 years. Center 2; 7 patients with CF (6 female) aged 13–18 years, and 6 healthy controls (6 female) aged 21–31 years. Data were acquired in different patients at each center. Field Strength/Sequence 1.5 T, 3D steady‐state free precession and 2D spoiled gradient echo. Assessment Subjects were scanned with 129 Xe ventilation and 1 H free‐breathing MRI and performed pulmonary function tests. Ventilation defect percent (VDP) was calculated using linear binning and images were visually assessed by H.M., L.J.S., and G.J.C. (10, 5, and 8 years' experience). Statistical Tests Correlations and linear regression analyses were performed between 129 Xe VDP, 1 H VDP, FEV 1 , and LCI. Bland–Altman analysis of 129 Xe VDP and 1 H VDP was carried out. Differences in metrics were assessed using one‐way ANOVA or Kruskal–Wallis tests. Results 129 Xe VDP and 1 H VDP correlated strongly with; each other ( r = 0.84), FEV 1 z‐score ( 129 Xe VDP r = −0.83, 1 H VDP r = −0.80), and LCI ( 129 Xe VDP r = 0.91, 1 H VDP r = 0.82). Bland–Altman analysis of 129 Xe VDP and 1 H VDP from both centers had a bias of 0.07% and limits of agreement of −16.1% and 16.2%. Linear regression relationships of VDP with FEV 1 were not significantly different between 129 Xe and 1 H VDP ( P = 0.08), while 129 Xe VDP had a stronger relationship with LCI than 1 H VDP. Data Conclusion 1 H ventilation MRI shows large‐scale agreement with 129 Xe ventilation MRI in CF patients with established lung disease but may be less sensitive to subtle ventilation changes in patients with early‐stage lung disease. Evidence Level 2 Technical Efficacy Stage 2