PT - JOURNAL ARTICLE AU - Derdeyn, Colin P. AU - Grubb Jr., Robert L. AU - Powers, William J. TI - Reply DP - 2001 Jan 01 TA - American Journal of Neuroradiology PG - 227--0227 VI - 22 IP - 1 4099 - http://www.ajnr.org/content/22/1/227.short 4100 - http://www.ajnr.org/content/22/1/227.full SO - Am. J. Neuroradiol.2001 Jan 01; 22