1. Paracelsus-Elena-Klinik; Kassel and University Medical Center; Göttingen Germany
2. Clinical Ageing Research Unit, Institute for Ageing and Health, Campus for Ageing and Vitality; Newcastle University Newcastle upon Tyne; United Kingdom
3. Department of Neurology; Perelman School of Medicine at the University of Pennsylvania, Hospital of the University of Pennsylvania; Philadelphia Pennsylvania USA
4. Department of Medicine; Imperial College London. Hammersmith Hospital; London United Kingdom
5. Department of Nuclear Medicine; Aarhus University; Nørrebrogade Aarhus Denmark