1 Clinical Effectiveness Research Group, University of Oslo, Oslo, Norway; Department of Transplantation Medicine, Oslo University Hospital, Oslo, Norway; Digestive Disease Center, Showa University Northern Yokohama Hospital, Yokohama, Japan.
2 Digestive Disease Center, Showa University Northern Yokohama Hospital, Yokohama, Japan.
3 Computer Science Department, Universitat Autònoma de Barcelona and Computer Vision Center, Barcelona, Spain.
4 Clinical Effectiveness Research Group, University of Oslo, Oslo, Norway; Department of Transplantation Medicine, Oslo University Hospital, Oslo, Norway.
5 Division of Gastroenterology, University of Kansas Medical Center, Kansas City, Kansas, USA.
6 Endoscopy Unit, Gastroenterology Department, Hospital Clínic, University of Barcelona, Barcelona, Spain.