1. Stroke unit, Department of Neurology, Oslo University Hospital, Oslo, Norway
2. Unit for hyperbaric medicine, Department of Anaesthesiology, Oslo University Hospital, Oslo, Norway
3. Department of Radiology, Elverum Hospital, Elverum, Norway
4. Neuroscience Research Group, Stavanger University Hospital, Stavanger, Norway
5. Department of Radiology, Oslo University Hospital, Oslo, Norway