RT Journal Article SR Electronic T1 Composite addition technique: a new method in CT scanning of the posterior fossa. JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 686 OP 688 VO 12 IS 4 A1 J M Levy A1 R Hupke YR 1991 UL http://www.ajnr.org/content/12/4/686.abstract AB