1. Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
2. Thoracic radiology, Imaging and Physiology, Karolinska University Hospital, Stockholm, Sweden
3. Department of Radiology, Imperial College NHS Trust, Hammersmith Hospital, London, Britain
4. Department of Clinical Sciences, Karolinska Institutet, Danderyds Hospital, Stockholm, Sweden
5. Division of Medicine, Danderyds Hospital, Stockholm, Sweden