[1] Birmingham Heartlands Hosp, W Midlands Adult Cyst Fibrosis Ctr, Birmingham B9 5SS, W Midlands, England
[2] Univ Toronto, St Michaels Hosp, Toronto Adult CF Program, Toronto, ON M5B 1W8, Canada
[3] Univ Hosp Coventry, Dept Radiol, Coventry, W Midlands, England
[4] Warwickshire NHS Trust, Coventry, W Midlands, England
[5] Li Ka Shing Knowledge Inst, Toronto, ON, Canada
[6] Univ Toronto, Hosp Sick Children, Res Inst, Toronto, ON M5G 1X8, Canada