[1] Univ Hosp Cologne, Dept Radiol, D-50937 Cologne, Germany
[2] Univ Bonn, German Ctr Neurodegenerat Dis DZNE, Dept Psychiat, D-53105 Bonn, Germany
[3] Univ Med Ctr Mainz, Dept Psychiat & Psychotherapy, D-55131 Mainz, Germany
[4] Univ Hosp Cologne, Dept Nucl Med, Kerpener St 62, D-50937 Cologne, Germany