1 Department of Radiology, University College London Hospital, 235 Euston Road, London, NW1 2BU, UK.
2 Department of Radiology, Royal United Hospitals Bath NHS Foundation Trust, Combe Park, Bath, BA1 3NG, UK.
3 Department of Radiology, Royal Free London NHS Trust, Pond Street, London, NW3 2QJ, UK.
4 Department of Radiology, Southmead Hospital, North Bristol NHS Trust, Southmead Road, Bristol, BS10 5NB, UK.
5 Department of Radiology, The Royal Brompton & Harefield NHS Foundation Trust London, SW3 6NP, UK.
6 Department of Respiratory Medicine, University College London, London, NW1 2BU, UK; Centre for Medical Image Computing, University College London, London, NW1 2BU, UK.
7 Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds General Infirmary, Great George Street, Leeds, LS1 3EX, UK.
8 Department of Radiology, Freeman Hospital, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Freeman Road, Newcastle Upon Tyne, NE7 7DN, UK.
9 Department of Radiology, Norfolk and Norwick University Hospital, Colney Lane, Norwich, NR4 7UY, UK.
10 Department of Radiology, Royal United Hospitals Bath NHS Foundation Trust, Combe Park, Bath, BA1 3NG, UK. Electronic address: grobinson1@nhs.net.