1. Department of Medicine, Haukeland Universitetssjukehus, Bergen, Norway
2. Department of Clinical Medicine, University of Bergen, Norway
3. Department of Clinical Medicine, Universitetet i Bergen Det Matematisk-naturvitenskapelige Fakultet, Bergen, Norway
4. Department of Clinical Medicine, Universitetet i Bergen Det medisinsk-odontologiske fakultet, Bergen, Norway
5. National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, Bergen, Norway