1. Department of Radiology, University College London Hospitals NHS Foundation Trust , 235 Euston Road, London NW1 2BU , United Kingdom
2. Department of Gastroenterology, Northern Hospital , Epping, Melbourne , Australia
3. Department of Cardiology, Harefield Hospital, Royal Brompton and Harefield NHS Foundation Trust , Uxbridge, UB9 6JH , United Kingdom
4. Department of Gastroenterology, Whipps Cross University Hospital, Barts Health NHS Trust , Whipps Cross Road, London E11 1NR , United Kingdom
5. Department of Gastroenterology, Heartlands Hospital, University Hospitals Birmingham NHS Foundation Trust , Bordesley Green East, Birmingham, B9 5SS , United Kingdom
6. Department of Medicine, University of Melbourne , Parkville, Melbourne , Australia