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Patterns of regional lung physiology in cystic fibrosis using ventilation MRI and MBW.

Research paper by Laurie J LJ Smith, Guilhem J GJ Collier, Helen H Marshall, Paul J C PJC Hughes, Alberto M AM Biancardi, Martin M Wildman, Ina I Aldag, Noreen N West, Alex A Horsley, Jim M JM Wild

Indexed on: 27 Oct '18Published on: 27 Oct '18Published in: European Respiratory Journal



Abstract

Hyperpolarised helium-3 (He) ventilation MRI and multiple-breath washout (MBW) are sensitive methods for detecting lung disease in cystic fibrosis (CF). We aimed to explore their relationship across a broad range of CF disease severity and patient age, as well as assess the effect of inhaled lung volume on ventilation distribution.32 children and adults with CF underwent MBW and He-MRI at a lung volume of end-inspiratory tidal volume (EIVt). 28 patients also performed He-MRI at total lung capacity (TLC). He-MRI were quantitatively analysed for; ventilation defect percentage (VDP), ventilation heterogeneity index (VH), and the number and size of individual contiguous ventilation defects. From MBW, the lung clearance index (LCI), S and S were calculated.VDP and VH at EIVt strongly correlated with LCI (r=0.89, r=0.88 respectively), S (r=0.84, r=0.82) and FEV (r=-0.79, r=-0.78). Two distinct He-MRI patterns were highlighted; patients with abnormal FEV had significantly (p<0.001) larger, but fewer contiguous defects than those with normal FEV who tended to have numerous small volume defects. These two MRI patterns were delineated by a VDP of approximately 10%. At TLC, when compared to EIVt, VDP and VH reduced in all subjects (p<0.001), demonstrating improved ventilation distribution and also regions of volume-reversible and non-reversible ventilation abnormalities. Copyright ©ERS 2018.