Comparison of CT findings of biliary tract changes with autoimmune pancreatitis and extrahepatic bile duct cholangiocarcinoma.
OBJECTIVE
To retrospectively evaluate criteria for differentiating biliary tract changes in autoimmune pancreatitis (AIP-BTC) from extrahepatic cholangiocarcinoma (ECCA) based on CT findings and to determine predictors for differentiation between the two disorders.


METHODS
CT findings of 22 patients with AIP-BTC and 45 patients with ECCA, both with positive CT findings in the biliary system, were retrospectively assessed. The images were assessed for presence of biliary obstruction, diameter of the maximally dilated biliary duct, maximum thickness of the involved duct, presence of masses inside or around the involved ducts, lengths of the biliary lesions, concentricity of wall thickening, multifocality of the lesion, and degree of lesion enhancement.


RESULTS
Compared with AIP-BTC, ECCA was significantly more frequently associated with biliary obstruction (p = 0.0037), shorter lengths of the biliary lesions (p = 0.0036), and masses (p < 0.001). No significant differences were found for other items.


CONCLUSIONS
Presence of obstructive dilatation of the bile ducts and intraluminal or peri-ductal masses and length of the thickened wall may help differentiate between AIP-BTC and ECCA.
Department of Radiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. emaeda-tky@umin.ac.jp
Eriko
E
Maeda
Masaaki
M
Akahane
Naoki
N
Yoshioka
Hidemasa
H
Takao
Izuru
I
Matsuda
Kouhei
K
Kamiya
Kenji
K
Hirano
Minoru
M
Tada
Hiroshi
H
Ohtsu
Noriyoshi
N
Fukushima
Kuni
K
Ohtomo
D000368:Aged; D001327:Autoimmune Diseases / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D017734:Bile Ducts, Extrahepatic; D018281:Cholangiocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010195:Pancreatitis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media