[1] Univ Cologne, Dept Neurol, Cologne, Germany
[2] Forschungszentrum Julich, Inst Neurosci & Med, D-52425 Julich, Germany
[3] Univ Cologne, CIO, Cologne, Germany
[4] Univ Bonn, Cologne, Germany
[5] Univ Copenhagen, Rigshosp, Dept Clin Physiol Nucl Med & PET, Copenhagen, Denmark
[6] Univ Calif Los Angeles, David Geffen Sch Med, Dept Radiol Sci, Los Angeles, CA 90095 USA
[7] Univ Navarra, Clin Univ Navarra, Dept Nucl Med, Pamplona, Spain
[8] Univ Aachen, Dept Nucl Med, Aachen, Germany