[1] Philipps Univ Marburg, Nucl Med Dept, Radiopharm, Marburg, Germany
[2] Tech Univ Munich, Dept Nucl Med, Munich, Germany
[3] Karolinska Inst, Dept Clin Neurosci, Stockholm, Sweden
[4] Uppsala Univ, Dept Phys & Astron, Uppsala, Sweden
[5] Philipps Univ Marburg, Nucl Med Dept, Marburg, Germany
[6] Ludwig Maximilians Univ Munchen, Munich, Germany