Regional ventilation evaluation of abnormalities of the lung in cystic fibrosis (ReVEAL-CF Study)

Pulmonary Function Testing(PFT) is a valuable tool for assessing lung function however it does not provide information about regional ventilation. This study aims to investigate the potential of X-ray Velocimetry (XV, 4DMedical Limited, Australia) to quantify and spatially map specific ventilation in patients with Cystic Fibrosis(CF). In this cross-sectional study we aim to recruit 20 adults with stable CF(no medication changes or recent hospitalisation). 6 patients have been examined to date. XV allows for the measurement of ventilation heterogeneity, VH(interquartile range of regional volumes normalised by the mean volume) and low ventilation regions LVR(proportion of lung with regional tidal volumes less than 50μL) in each voxel. PFTs (spirometry, lung volumes, and DLCO) were also conducted. XV imaging highlighted ventilation heterogeneity and individual ventilation distribution patterns. VH ranged between 42 and 53% and LVR between 13 and 32% while PFTs indicated mild airflow limitation. Patient 6 illustrates the advantages of XV compared to spirometry; despite normal spirometry (FEV1: 99% predicted, FEV1/FVC:96% predicted), XV revealed high ventilation heterogeneity(VH:42%) and significant proportion of low ventilation regions(LVR:32%) <fig><object-id>erj;64/suppl_68/OA2907/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> XV offers a novel method to visualise and quantify individual variability in disease burden and may provide additional information about lung function to aid clinical management.