RT Journal Article SR Electronic T1 Coffee-bean sign JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 1657 OP 1657 DO 10.1503/cmaj.071760 VO 178 IS 13 A1 Yu-Sung Lee MD A1 Wei-Jing Lee MD YR 2008 UL http://www.cmaj.ca/content/178/13/1657.abstract