1. Institute
of Neuroscience and Medicine, INM-5: Nuclear Chemistry, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
2. Institute
of Radiochemistry and Experimental Molecular Imaging, University Clinic Cologne, Cologne 50937, Germany
3. Max Planck Institute for Metabolism Research, Cologne 50931, Germany
4. Department
of Nuclear Medicine, University Clinic Cologne, Cologne 50937, Germany