RT Journal Article SR Electronic T1 The choice of contrast media: medical, ethical and legal considerations JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 1321 OP 1324 VO 147 IS 9 A1 D. J. Roy A1 B. M. Dickens A1 M. McGregor YR 1992 UL http://www.cmaj.ca/content/147/9/1321.abstract