title: Characterization of biliary strictures using intraductal ultrasonography: comparison with percutaneous cholangioscopic biopsy.
abstract: BACKGROUND
  We determined the accuracy of intraductal ultrasonography (IDUS) in distinguishing between bile duct cancer and benign bile duct disease.
  
  
  METHODS
  Patients (n=42) who required bile duct biopsy using percutaneous transhepatic cholangioscopy (PTCS) to evaluate bile duct strictures or filling defects were studied. A thin-caliber ultrasonic probe (2.0 mm diameter and 20 MHz frequency) was inserted into the bile duct, and its images were prospectively reviewed before PTCS.
  
  
  RESULTS
  Disruption of the bile duct wall structure, seen on IDUS, was associated with malignancy in 25 of 26 patients. When IDUS demonstrated a lesion with normal bile duct structure, six of nine patients were found to have no malignancy. IDUS demonstrated no intraductal lesion in seven patients, and bile duct biopsy also did not indicate cancer in any of these patients. The accuracy, sensitivity, and specificity of IDUS for diagnosing bile duct cancer were 76%, 89%, and 50%, respectively. When used in tandem with IDUS, the sensitivity of bile cytology (64%) and PTCS (93%) improved to 96% and 100%, respectively.
  
  
  CONCLUSIONS
  The accuracy of IDUS for diagnosing bile duct cancer was less than that of PTCS (95%). However, the sensitivity for bile cytology, or bile duct biopsy improved when performed in combination with IDUS.
authors.affiliation: Department of Gastroenterology, Jichi Medical School, Tochigi, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tamada
authors.forename: N
authors.initials: N
authors.lastname: Ueno
authors.forename: T
authors.initials: T
authors.lastname: Tomiyama
authors.forename: A
authors.initials: A
authors.lastname: Oohashi
authors.forename: S
authors.initials: S
authors.lastname: Wada
authors.forename: T
authors.initials: T
authors.lastname: Nishizono
authors.forename: S
authors.initials: S
authors.lastname: Tano
authors.forename: T
authors.initials: T
authors.lastname: Aizawa
authors.forename: K
authors.initials: K
authors.lastname: Ido
authors.forename: K
authors.initials: K
authors.lastname: Kimura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001649:Bile Duct Diseases / Q000175:diagnosis*; D001650:Bile Duct Neoplasms / Q000175:diagnosis; D001707:Biopsy, Needle / Q000379:methods*; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging / Q000473:pathology; D003937:Diagnosis, Differential; D016145:Endoscopy, Digestive System; D019160:Endosonography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity