RT Journal Article SR Electronic T1 Validating PET Scanner Calibration for Multicenter Trials JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 997 OP 998 DO 10.2967/jnumed.109.069989 VO 51 IS 6 A1 Lilli Geworski A1 Bernd Knoop YR 2010 UL http://jnm.snmjournals.org/content/51/6/997.abstract AB