[1] Hosp Univ Penn, Dept Radiol, Philadelphia, PA 19104 USA
[2] Tata Mem Hosp, Radiat Med Ctr BARC, Bombay 400012, Maharashtra, India
[3] Uppsala Univ, Dept Biochem & Organ Chem, Uppsala, Sweden
[4] Univ So Denmark, Dept Nucl Med, Odense, Denmark
[5] Univ London Imperial Coll Sci Technol & Med, Ctr Pharmacol & Therapeut, Neuropsychopharmacol Unit, London, England