title: Mass-forming cholangiocarcinoma and adenocarcinoma of unknown primary: can they be distinguished on liver MRI?
abstract: OBJECTIVE
  To determine MR features suggestive of mass-forming cholangiocarcinoma (CCA) or liver metastases of adenocarcinoma of unknown primary (AUP), and to compare the ability of two experienced radiologists to establish the correct diagnosis.
  
  
  METHODS
  61 patients with CCA or AUP, with MRIs were placed into two groups: population 1, 28 patients with certain diagnosis of either CCA or AUP; and population 2, 33 patients with uncertain diagnosis. Using population 1 with known diagnosis, two investigators formulated imaging criteria for CCA or AUP, which represented phase 1 of the study. In phase 2, two independent radiologists categorized the patients in populations 1 and 2 as CCA or AUP using the formulated criteria. This categorization was compared with the patient medical records and pathologist review. Findings were tested for statistical significance.
  
  
  RESULTS
  In phase 1, solitary lesion, multifocal lesions with dominant lesion, capsule retraction, and porta hepatis lymphadenopathy were features of CCA; multifocal lesions with similar size, and ring enhancement were features of AUP. The number of lesions, capsule retraction, and early tumor enhancement pattern were observed to be significant features (P < 0.05). In phase 2, agreement between the two radiologists was good (k = 0.663). For population 1, the agreement was good (k = 0.659), and was fair for population 2 (k = 0.293). Concordance between the two radiologists, medical record, and the pathologist was found in 41/61 (67%) patients.
  
  
  CONCLUSIONS
  Distinctive features of CCA and AUP are identifiable on MRI images, which may aid the radiologist to establish the correct diagnosis.
authors.affiliation: Department of Radiology, University of North Carolina at Chapel Hill, CB 7510 - 2001 Old Clinic Bldg, Chapel Hill, NC, 27599-7510, USA.
authors.forename: Najwa
authors.initials: N
authors.lastname: Al Ansari
authors.forename: Bong Soo
authors.initials: BS
authors.lastname: Kim
authors.forename: Saowanee
authors.initials: S
authors.lastname: Srirattanapong
authors.forename: Charles T A
authors.initials: CT
authors.lastname: Semelka
authors.forename: Miguel
authors.initials: M
authors.lastname: Ramalho
authors.forename: Ersan
authors.initials: E
authors.lastname: Altun
authors.forename: John T
authors.initials: JT
authors.lastname: Woosley
authors.forename: Benjamin
authors.initials: B
authors.lastname: Calvo
authors.forename: Richard C
authors.initials: RC
authors.lastname: Semelka
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000175:diagnosis*; D001653:Bile Ducts, Intrahepatic / Q000473:pathology*; D018281:Cholangiocarcinoma / Q000175:diagnosis*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008099:Liver / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives; D008875:Middle Aged; D015588:Observer Variation; D009942:Organometallic Compounds; D015203:Reproducibility of Results
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine