1. Faculty of Health Sciences, University of Tromsø, Breivika 9037, Tromsø, Norway.
2. Department of Radiology, University Hospital of North Norway, Tromsø, Norway.
3. Department for Radiology and Intervention, Oslo University Hospital, Oslo, Norway.
4. Department of Radiology, Haukeland University Hospital, Bergen, Norway.
5. Department of Clinical Medicine, University of Bergen, Bergen, Norway.