title: Helical CT cholangiography with three-dimensional volume rendering using an oral biliary contrast agent: feasibility of a novel technique.
abstract: OBJECTIVE
  We evaluated the feasibility and image quality of a new noninvasive biliary imaging technique: helical CT cholangiography with three-dimensional volume rendering using an oral biliary contrast agent.
  
  
  METHODS
  Nineteen subjects including five healthy volunteers and 14 patients underwent helical CT cholangiography. Subjects ingested 6.0 g of iopanoic acid 6-10 hr before undergoing imaging. Axial data were used to construct three-dimensional volume-rendered cholangiograms. Two radiologists, an endoscopist, and a laparoscopic surgeon reviewed the images and evaluated overall image quality. In the 14 patients, findings from CT cholangiography were compared with those from ERCP, surgery, and intraoperative cholangiography.
  
  
  RESULTS
  All segments of the biliary tree were opacified in all volunteers except one, in whom the intrahepatic ducts were not opacified. Image quality was good to excellent in all volunteers. Anomalous cystic duct insertions were seen in two volunteers. Opacification of the biliary tree was rated as acceptable to excellent in nine patients and suboptimal in five. In five patients with good or excellent opacification, the biliary anatomy correlated with findings on intraoperative cholangiography or ERCP. CT cholangiography revealed additional conditions (gallbladder varices and acute pancreatitis) and variant anatomy in three patients.
  
  
  CONCLUSIONS
  Results of this pilot project suggest that obtaining CT cholangiograms using an oral biliary contrast agent is a feasible, noninvasive method for revealing biliary anatomy. However, visualization of the biliary tree was suboptimal in 36% of the patients, which represents a limitation of this technique.
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: E M
authors.initials: EM
authors.lastname: Caoili
authors.forename: E K
authors.initials: EK
authors.lastname: Paulson
authors.forename: L E
authors.initials: LE
authors.lastname: Heyneman
authors.forename: M S
authors.initials: MS
authors.lastname: Branch
authors.forename: W S
authors.initials: WS
authors.lastname: Eubanks
authors.forename: R C
authors.initials: RC
authors.lastname: Nelson
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001660:Biliary Tract Diseases / Q000000981:diagnostic imaging*; D002758:Cholangiography / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007480:Iopanoic Acid / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007480:Iopanoic Acid