1. Royal Free Unit for Endoscopy, The Royal Free Hospital and University College London (UCL) Institute for Liver and Digestive Health, London, United Kingdom
2. Depatment of Radiology, The Royal Free Hospital and UCL Institute for Liver and Digestive Health, London, United Kingdom
3. Academic Department of Cellular Pathology, The Royal Free Hospital and UCL Institute for Liver and Digestive Health, London, United Kingdom