title: Differentiating malignant from benign common bile duct stricture with multiphasic helical CT.
abstract: OBJECTIVE
  To evaluate retrospectively the use of multiphasic helical computed tomography (CT) to differentiate malignant and benign common bile duct (CBD) strictures in patients with only a focal CBD stricture and to determine predictors for this differentiation.
  
  
  METHODS
  Institutional review board approval and informed patient consent were not required. Fifty patients (35 men, 15 women; age range, 35-87 years; mean age, 61.6 years) with only a focal CBD stricture comprised the sample for this study (32 malignant and 18 benign strictures). The diagnosis of all malignant and five benign CBD strictures was confirmed by reviewing patients' surgical and pathology records; in 13 benign CBD strictures, the diagnosis was confirmed by means of clinical features. Multiphasic CT findings were analyzed with regard to the wall thickness, location, length, and enhancement pattern of the involved CBD, the upstream CBD diameter, and other findings. CT features to identify benign and malignant CBD strictures were compared by means of univariate analysis and multivariable stepwise logistic regression analysis.
  
  
  RESULTS
  Malignant strictures were longer (17.9 mm +/- 6.6 [+/- standard deviation]) than benign strictures (8.9 mm +/- 6.8) (P < .0001), and upstream CBD diameters were larger in malignant cases (22.0 mm +/- 5.4) than in benign cases (17.8 mm +/- 4.6) (P = .033). The involved wall thickness was more than 1.5 mm in 26 malignant cases and three benign cases (P < .0001). During both hepatic arterial and portal venous phases, greater enhancement than that in the normal CBD were more frequently observed in malignant cases (in 27 and 30 patients for hepatic arterial and portal venous phase scans, respectively) than in benign cases (in two and three patients, respectively) (P < .0001). Results of multivariable stepwise logistic regression analysis showed that hyperenhancement of the involved CBD during the portal venous phase was the only variable that could be used to independently differentiate malignant from benign strictures.
  
  
  CONCLUSIONS
  Hyperenhancement of the involved CBD during the portal venous phase is the main factor distinguishing malignant from benign CBD strictures.
authors.affiliation: Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Clinical Research Institute, Seoul National University Hospital, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Korea.
authors.forename: Seung Hong
authors.initials: SH
authors.lastname: Choi
authors.forename: Joon Koo
authors.initials: JK
authors.lastname: Han
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Kyoung Ho
authors.initials: KH
authors.lastname: Lee
authors.forename: Se Hyung
authors.initials: SH
authors.lastname: Kim
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Byung Ihn
authors.initials: BI
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D003137:Common Bile Duct Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D003138:Common Bile Duct Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D036542:Tomography, Spiral Computed