Longitudinal monitoring of disease progression in children with mild CF using hyperpolarised gas MRI and LCI

Introduction: FEV 1 is insensitive to early changes in lung disease in cystic fibrosis (CF). Hyperpolarised gas ventilation MRI (HP-MRI) is more sensitive than FEV 1 , CT and the lung clearance index (LCI) at detecting early lung disease in CF and therefore may be more sensitive to longitudinal change. Aim: To assess changes in lung disease using HP-MRI, LCI and spirometry in a group of children with mild CF at 2 year intervals. Methods: 7 children with CF and FEV 1 u003e-1.64 z-score were assessed at baseline and 2 years later. Results: Subjects FEV 1 did not significantly change (Figure 1). 2/7 subjects had an abnormal LCI at baseline. At 2 years, LCI had increased significantly (p=0.03) and 5/7 subjects had an abnormal LCI. All subjects had ventilation defects evident on HP-MRI, which significantly worsened at 2 years - ventilated volume (VV) % reduced (p=0.01) and the coefficient of variance (CV) (inter-voxel ventilation heterogeneity) increased (p=0.03). Conclusion: In CF subjects with non-clinical lung disease, HP gas ventilation MRI is more sensitive at detecting longitudinal lung function deterioration than both LCI and FEV 1 .