1. Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
2. Department of Research, Norwegian Air Ambulance Foundation, Norway
3. Department of Neurology, Oslo University Hospital, Oslo, Norway
4. Department of Health Science, Oslo Metropolitan University, Oslo, Norway
5. Department of Radiology, Østfold Hospital, Sarpsborg, Norway
6. Department of Medicine, Ringerike Hospital, Vestre Viken Hospital Trust, Honefoss, Norway
7. Division of Prehospital Services, Oslo University Hospital, Oslo, Norway