1. Nuclear Chemistry (INM-5), Institute of Neuroscience and Medicine, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
2. Institute of Radiochemistry and Experimental Molecular Imaging, University of Cologne, Faculty of Medicine, and University Hospital Cologne, 50937 Cologne, Germany
3. Nuclear Medicine Department, University of Cologne, Faculty of Medicine, and University Hospital Cologne, 50937 Cologne, Germany
4. Max Planck Institute of Metabolism Research, 50931 Cologne, Germany