1. Department of Gastroenterology, Akershus University Hospital, 1478 Lorenskog, Norway
2. Department of Pathology, Norwegian Radium Hospital, Oslo University Hospital, 0310 Oslo, Norway
3. Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0372 Oslo, Norway
4. Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7030 Trondheim, Norway
5. Department of Dermatology, St. Olavs Hospital, Trondheim University Hospital, 7030 Trondheim, Norway
6. Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China