Differentiating malignant from benign common bile duct stricture with multiphasic helical CT.
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.
Choi
Seung Hong
SH
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.
Han
Joon Koo
JK
Lee
Jeong Min
JM
Lee
Kyoung Ho
KH
Kim
Se Hyung
SH
Lee
Jae Young
JY
Choi
Byung Ihn
BI
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