title: CT imaging of biliary enteric fistula.
abstract: BACKGROUND
  To define the signs useful for differentiating between gallbladder-enteric fistula (GB-EF) and common bile duct-enteric fistula (CBD-EF) on computed tomography (CT) because the prognosis and management of the two are different.
  
  
  METHODS
  CT scans in 13 patients with pneumobilia, who had not had surgical biliary-enteric anastomosis and endoscopic sphincterotomy, were reviewed. The presence of fistula itself, the location of air in the biliary system, and the appearance of the gallbladder were assessed.
  
  
  RESULTS
  The causes of pneumobilia were GB-EF in seven patients, CBD-EF in three patients, emphysematous cholecystitis (EC) in one patient, gallbladder cancer (GBC) in one patient, and incompetent sphincter of Oddi in one patient. In three of seven GB-EF patients (43%) and in none of the three CBD-EF patients (0%), the fistula itself was detected. Air was detected in the common bile duct in four of seven GB-EF (57%) and in all three CBD-EF (100%) patients, and GBC. In six of seven GB-EF (86%) and in one of three CBD-EF (33%) patients, the gallbladder was contracted. Thus, the location of air and the contraction of gallbladder were useful signs to differentiate GB-EF from CBD-EF.
  
  
  CONCLUSIONS
  CT can distinguish between GB-EF and CBD-EF.
authors.affiliation: Department of Radiology, Kyoto City Hospital, Kyoto, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Shimono
authors.forename: K
authors.initials: K
authors.lastname: Nishimura
authors.forename: K
authors.initials: K
authors.lastname: Hayakawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001658:Biliary Fistula / Q000000981:diagnostic imaging*; D003137:Common Bile Duct Diseases / Q000000981:diagnostic imaging; D005260:Female; D005705:Gallbladder Diseases / Q000000981:diagnostic imaging; D006801:Humans; D007412:Intestinal Fistula / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed