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

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.

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.

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.

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.