[1] Univ Cologne, Fac Med, Dept Nucl Med, Cologne, Germany
[2] Univ Cologne, Univ Hosp Cologne, Cologne, Germany
[3] Univ Cologne, Dept Nucl Med, Cologne, Germany
[4] INM 5, Julich, Germany
[5] Univ Cologne, Inst Radiochem & Expt Mol Imaging, Cologne, Germany
[6] Forschungszentrum Julich, Nucl Chem, Inst Neurosci & Med INM 5, Julich, Germany
[7] Univ Hosp Cologne, Dept Nucl Med, Cologne, Germany
[8] Inst Neurosci & Med INM 2, Mol Org Brain, Julich, Germany