title: Comparison of the multidetector-row computed tomography findings of IgG4-related sclerosing cholangitis and extrahepatic cholangiocarcinoma.
abstract: OBJECTIVE
  To compare the multidetector-row computed tomography (MDCT) findings of IgG4-related sclerosing cholangitis (IgG4-SC) and extrahepatic cholangiocarcinoma (EH-CCA).
  
  
  METHODS
  Two radiologists who had no knowledge of the patients' clinical information retrospectively evaluated the CT findings of patients with IgG4-SC (n=33) and EH-CCA (n=39) on a consensus basis. Another radiologist measured the biliary lesions. IgG4-SC was diagnosed using the Japan Biliary Association criteria (2012) or the Mayo Clinic's HISORt criteria. EH-CCA was diagnosed based on surgical findings.
  
  
  RESULTS
  Compared with EH-CCA, IgG4-SC exhibited the following findings significantly more frequently: (a) wall thickening alone, (b) concentric wall thickening, (c) smooth inner margins, (d) homogeneous attenuation in the arterial phase, (e) a lesion involving the intrapancreatic bile duct, (f) smooth outer margins, (g) fully visible lumen, (h) a funnel-shaped proximal bile duct, (i) skip lesions, and (j) abnormal pancreatic findings. Conversely, (k) dual-layered attenuation in all phases was significantly more common in EH-CCA. The specificity values of parameters (e-k) were >80%. Regarding dimensions, (l) the biliary lesions were longer in IgG4-SC than in EH-CCA. (m) The diameters of the dilated proximal common bile duct and (n) the dilated proximal intrahepatic bile duct were smaller in IgG4-SC than in EH-CCA.
  
  
  CONCLUSIONS
  A number of CT findings are useful for differentiating between IgG4-SC and EH-CCA. CT findings (e-k) are particularly useful for this purpose.
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 466-8550, Japan. Electronic address: yata-m@med.nagoya-u.ac.jp.
authors.forename: M
authors.initials: M
authors.lastname: Yata
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 466-8550, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 466-8550, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Furuhashi
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 466-8550, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kawakami
authors.affiliation: Department of Diagnostic Radiology, Japanese Red Cross Nagoya Daiichi Hospital, 3-15 Michishita-cho, Nakamura-ku, Nagoya, Aichi 453-8511, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kawai
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 466-8550, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Naganawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging* / Q000276:immunology / Q000601:surgery; D017734:Bile Ducts, Extrahepatic; D018281:Cholangiocarcinoma / Q000000981:diagnostic imaging* / Q000276:immunology / Q000601:surgery; D015209:Cholangitis, Sclerosing / Q000000981:diagnostic imaging* / Q000276:immunology / Q000601:surgery; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D007074:Immunoglobulin G