RT Journal Article SR Electronic T1 Three-Dimensional Imaging Characteristics of the HEAD PENN-PET Scanner JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 636 OP 643 VO 38 IS 4 A1 Joel S. Karp A1 Richard Freifelder A1 Michael J. Geagan A1 Gerd Muehllehner A1 Paul E. Kinahan A1 Robert M. Lewitt A1 Lingxiong Shao YR 1997 UL http://jnm.snmjournals.org/content/38/4/636.abstract AB