Hyperpolarised gas ventilation MRI detects early lung ventilation heterogeneity in children with primary ciliary dyskinesia

Abstract

Introduction: Assessment of lung disease in primary ciliary dyskinesia (PCD) is challenging. As lung disease is progressive, early detection would inform early intervention and treatment. Hyperpolarised gas ventilation MRI (HP-MRI) has been shown to be more sensitive than FEV 1 , HRCT and LCI at detecting early lung disease in cystic fibrosis and may have a similar role in PCD. Aim: To assess HP-MRI as a modality to detect early lung disease in PCD. Methods: Children with confirmed PCD were assessed using HP-MRI, LCI calculated using 0.2% SF 6 and spirometry during a single visit. The quantitative HP-MRI metrics of ventilated defect % (VD) and coefficient of variation (CV) (a measure of ventilation heterogeneity) were calculated. Results: 5 children of median (range) age=12.2 (10.1-17.0) years were assessed. All subjects had ventilation defects visible on HP-MRI (VD=2.9 (2.1-13.2)%, CV=13.4 (10.8-19.1)%) but only 1 child had abnormal lung function (FEV 1 z-score=-2.11, LCI=8.08). 4/5 children had normal FEV 1 (z-score >-1.64) and LCI ( Conclusion: HP-MRI has the sensitivity to detect early lung ventilation heterogeneity in PCD when both FEV 1 and LCI are normal. HP-MRI in 2 subjects with PCD. Subject A has clear ventilation heterogeneity with multiple defects present and abnormal FEV1 and LCI. Ventilation defects are also present in Subject B (white arrows), with normal FEV1 and LCI.