RT Journal Article SR Electronic T1 Sigmoidal Curves—Reply JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 2196 OP 2196 VO 39 IS 12 A1 Pat Zanzonico A1 George Sgouros YR 1998 UL http://jnm.snmjournals.org/content/39/12/2196.3.abstract AB