1. Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark
2. Department of Clinical Research, University of Southern Denmark, Odense, Denmark
3. Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA, USA
4. Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
5. Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA