1. HUS Diagnostic Center, Radiology, University of Helsinki and Helsinki University Hospital, Finland
2. Radiation and Nuclear Safety Authority – STUK, Helsinki, Finland
3. Department of Physics, University of Helsinki, Helsinki, Finland
4. Department of Medical Physics, Kymsote, Kymenlaakso Central Hospital, Helsinki, Finland
5. HUS Abdominal Center, Endoscopy Department, University of Helsinki and Helsinki University Hospital, Finland