title: CT findings of intraductal papillary neoplasm of the bile duct: assessment with multiphase contrast-enhanced examination using multi-detector CT.
abstract: OBJECTIVE
  To evaluate multi-detector computed tomography (MDCT) findings of intraductal papillary neoplasm of the bile duct (IPNB), a neoplasm that is considered to be the biliary counterpart of pancreatic intraductal papillary mucinous neoplasm.
  
  
  METHODS
  Two radiologists retrospectively evaluated multiphase contrast-enhanced CT images with 0.5 or 1mm collimation in 37 consecutive patients with resected IPNB diagnosed by a single pathologist. The CT findings were correlated with the pathological findings concerning invasion of the surrounding organs and vessels.
  
  
  RESULTS
  All patients showed bile duct dilatation. An intraductal mass was detected in 36 patients and the following findings were observed: extensive infiltration along the bile duct more than 20mm (n=32), compared with normal hepatic parenchyma, isodense or hyperdense during the late arterial phase (n=31), not hyperdense during the portal-venous and delayed phases (n=36), and intense enhancement rim at the base of the mass during the portal-venous or delayed phase (n=27). Parenchymal invasion of the surrounding organs was seen in eight of 16 tumours showing irregular or bulging margins. Vascular invasion was false positive in four of eight tumours.
  
  
  CONCLUSIONS
  IPNB exhibits relatively characteristic findings with multiphase contrast-enhanced examination using MDCT. A tendency to overestimate invasion of the surrounding organs and vessels was seen.
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan. ogawa.hiroshi@h.mbox.nagoya-u.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Ogawa
authors.forename: S
authors.initials: S
authors.lastname: Itoh
authors.forename: T
authors.initials: T
authors.lastname: Nagasaka
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Ota
authors.forename: S
authors.initials: S
authors.lastname: Naganawa
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000000981:diagnostic imaging*; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging*; D001653:Bile Ducts, Intrahepatic / Q000000981:diagnostic imaging*; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging*; D018281:Cholangiocarcinoma / Q000000981:diagnostic imaging*; D003287:Contrast Media; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media