title: Intrahepatic bile duct dilatation due to liver metastases from colorectal carcinoma.
abstract: OBJECTIVE
  The objective of our study was to assess the association between colorectal liver metastases and intrahepatic bile duct dilatation and compare its frequency with the frequency of intrahepatic bile duct dilatation in other common noncolorectal metastases and hepatocellular carcinoma (HCC).
  
  
  METHODS
  A retrospective review of the radiology database was performed to obtain the records of patients who underwent CT for staging of histologically proven colorectal carcinoma (n = 1,000), noncolorectal carcinomas (n = 1,000), and HCC (n = 226). The CT scans of the 2,226 patients were reviewed for the presence of liver metastases and masses, the presence of intrahepatic bile duct dilatation directly related to the masses, the size of the largest lesion, and the associated caliber of the dilated intrahepatic bile duct.
  
  
  RESULTS
  Of the 297 patients with colorectal liver metastases, 49 (16.5%) had intrahepatic bile duct dilatation, whereas of the 263 patients with noncolorectal liver metastases, only eight (3%) had dilated ducts. Thirteen (5.7%) of the 226 patients with HCC had intrahepatic bile duct dilatation. Intrahepatic bile duct dilatation was present in significantly more patients with colorectal liver metastases (p < 0.05) than those with noncolorectal and HCC metastases. The mean sizes of the lesions and mean caliber of the dilated bile duct from colorectal metastases, noncolorectal metastases, and HCC were 5.3, 3.9, and 5.6 cm, respectively, and 5.1, 4.6, and 4.8 mm, respectively. Overall lesion size irrespective of diagnosis had no significant correlation with the probability of bile duct dilatation (p = 0.16; odds ratio = 1.08; 95% CI, 0.97-1.20). Lesion size also did not have a significantly different effect on the probability of dilatation for the three diagnoses (p = 0.71). The caliber of bile duct dilatation did not significantly differ among the three groups of patients by diagnosis (p = 0.70).
  
  
  CONCLUSIONS
  Colorectal liver metastases have a significantly higher tendency to cause intrahepatic bile duct dilatation than noncolorectal metastases and HCC due to the characteristic features, such as cholangiocarcinoma, of intrabiliary growth. This association has important diagnostic, surgical, and prognostic implications that make it necessary to highlight this finding while communicating with clinical colleagues.
authors.affiliation: Abdominal Imaging Division, Department of Medical Imaging, University of Toronto, University Health Network and Mount Sinai Hospital, 610 University Ave., 3-957, Toronto, ON M5G 2M9, Canada. kartik.jhaveri@uhn.on.ca
authors.forename: Kartik S
authors.initials: KS
authors.lastname: Jhaveri
authors.forename: Jaydeep
authors.initials: J
authors.lastname: Halankar
authors.forename: Diego
authors.initials: D
authors.lastname: Aguirre
authors.forename: Masoom
authors.initials: M
authors.lastname: Haider
authors.forename: Gina
authors.initials: G
authors.lastname: Lockwood
authors.forename: Maha
authors.initials: M
authors.lastname: Guindi
authors.forename: Sandra
authors.initials: S
authors.lastname: Fischer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001653:Bile Ducts, Intrahepatic / Q000473:pathology*; D006528:Carcinoma, Hepatocellular / Q000150:complications* / Q000556:secondary*; D016009:Chi-Square Distribution; D015179:Colorectal Neoplasms / Q000473:pathology*; D003287:Contrast Media; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging / Q000209:etiology; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000150:complications* / Q000556:secondary*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014283:Triiodobenzoic Acids
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; C044834:iodixanol