title: Diagnosis of intrahepatic and common duct stones: combined unenhanced and contrast-enhanced helical CT in 1090 patients.
abstract: BACKGROUND
  We determined the accuracy of combined unenhanced and contrast-enhanced helical computed tomography (CT) for diagnosis of bile duct stones.
  
  
  METHODS
  During a 12-month period, 1090 patients who underwent combined CT and endoscopic retrograde cholangiography (ERC) or percutaneous transhepatic cholangioscopy (PTC) were enrolled in this study. The results of prospective CT interpretation regarding the presence of bile duct stones were compared with results of endoscopic stone removal, PTC and with surgical results. In 70 patients, detectability of stones on CT was evaluated depending on stone types.
  
  
  RESULTS
  Of 1090 study patients, 175 and 299 patients were confirmed to have intrahepatic and common duct stones, respectively. The sensitivity and specificity of combined CT were 73% and 98% for diagnosis of intrahepatic stones and 71% and 97% for common duct stones. Of 70 patients 24, 25, and 21 patients had cholesterol, black pigment, and brown pigment stones, respectively. Eleven of 24 cholesterol stones, 21 of 25 black pigment stones, and 15 of 21 brown pigment stones were detected on combined CT.
  
  
  CONCLUSIONS
  Combined CT is of limited sensitivity for detection of bile duct stones, especially in Western countries where cholesterol stones predominate. It may be of greater value in populations with a higher incidence of pigment stones. Other complementary imaging modalities are needed for patients with negative CT findings who are highly suspected to have biliary stones.
authors.affiliation: Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnab-dong, Songpa-ku, Seoul, 138-736, Korea.
authors.forename: Jeong Kyong
authors.initials: JK
authors.lastname: Lee
authors.forename: Tae Kyoung
authors.initials: TK
authors.lastname: Kim
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Byun
authors.forename: Ah Young
authors.initials: AY
authors.lastname: Kim
authors.forename: Hyun Kwon
authors.initials: HK
authors.lastname: Ha
authors.forename: Pyo Nyun
authors.initials: PN
authors.lastname: Kim
authors.forename: Moon-Gyu
authors.initials: MG
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D001653:Bile Ducts, Intrahepatic / Q000000981:diagnostic imaging*; D002760:Cholangiopancreatography, Endoscopic Retrograde; D002765:Cholecystography; D003287:Contrast Media; D005260:Female; D042882:Gallstones / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed / Q000379:methods*
chemical_list: D003287:Contrast Media