1. Faculty of Health Studies, University of Bradford , Richmond Road, Bradford, BD7 1DP, United Kingdom
2. Department of Medical Physics & Engineering, Leeds Teaching Hospitals NHS Trust , Leeds, West Yorkshire, LS1 3EX, United Kingdom
3. Wolfson Institute of Preventive Medicine, Queen Mary University of London , EC1M 6BQ, United Kingdom
4. Barts Clinical Trials Unit, Wolfson Institute of Population Health, Queen Mary University of London , EC1M 6BQ, United Kingdom
5. Department of Radiology, Leeds Teaching Hospitals NHS Trust , Leeds, LS1 3EX, United Kingdom
6. Division of Infection, Immunity & Respiratory Medicine, University of Manchester , M13 9NT, United Kingdom
7. Department of Respiratory Medicine, Leeds Teaching Hospitals NHS Trust , Leeds, LS1 3EX, United Kingdom