Structure and function imaging in primary ciliary dyskinesia: cross-sectional study with 129Xe ventilation/1H anatomical magnetic resonance imaging.

BACKGROUND

In primary ciliary dyskinesia (PCD), impaired mucociliary clearance leads to respiratory infections. Whilst forced expiratory volume in 1 s (FEV1) is commonly used to evaluate lung function in PCD its sensitivity to detect abnormalities in mild disease is limited. This study explores the utility of 129Xe ventilation and 1H anatomical magnetic resonance imaging (MRI) to assess lung health in children with PCD.

METHODS

This prospective cohort study assessed clinically stable children with PCD (aged 5-18 years) using 129Xe MRI, 1H MRI and spirometry during one session. Ventilation defect percentage (VDP) was the primary metric calculated from 129Xe MRI.

RESULTS

35 children were assessed (mean±sd age 12.3±3.3 years, FEV1 z-score -1.5±1.7). Most children had visible ventilation abnormalities and 82.8% had an abnormal 129Xe VDP (median (interquartile range) 129Xe VDP 6.3% (1.3-16.1%)). 16 participants had a normal FEV1 (z-score > -1.6); however, 12 of these individuals had abnormal 129Xe VDP. 1H MRI found 55.9% participants had a region of collapse, 61.3% had bronchiectasis and 50.0% had evidence of air trapping.

CONCLUSIONS

129Xe MRI can identify early lung function abnormalities in children with PCD and demonstrates that the extent of ventilation distribution abnormalities in PCD varies between individuals. 1H MRI provides complementary diagnostic information on structural abnormalities.