RT Journal Article SR Electronic T1 Have You Been Smoking Something That Is Biologically Active? JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 240 OP 242 VO 27 IS 2 A1 Harry J. Cloft YR 2006 UL http://www.ajnr.org/content/27/2/240.abstract AB