title: Accuracy of computed tomographic intravenous cholangiography (CT-IVC) with iotroxate in the detection of choledocholithiasis.
abstract: To determine the accuracy of computed tomographic intravenous cholangiography (CT-IVC) for detection of choledocholithiasis. Sixty-five patients undergoing endoscopic retrograde cholangiography (ERC) underwent CT-IVC prior to ERC, using a single detector helical CT following intravenous infusion of 100 ml iotroxate. Patients with bilirubin levels >3 times normal were excluded. ERC was indeterminate in three patients (4.7%) and CT-IVC in four (6.3%). Twenty-three patients had ductal calculi at ERC, and CT-IVC was positive in 22, with two false positives and one false negative: sensitivity 95.6%, specificity 94.3%. Stones were multiple in nine and solitary in 14. Of the 14 solitary stones, ten were <or=5 mm and eight were <or=4 mm. The bilirubin level in positive cases was within normal in 20. Maximum intensity projection (MIP) reformats showed stones in only 27% of cases and surface rendered (SR) reformats in none. CT-IVC is highly accurate for detection of ductal calculi, including single small calculi, with a normal or near normal serum bilirubin. Axial images should be used for interpretation rather than MIP or SR reformats.
authors.affiliation: Department of Radiology, Royal Melbourne Hospital, University of Melbourne, Mebourne, Victoria, 3050, Australia. r.gibson@unimelb.edu.au
authors.forename: Robert N
authors.initials: RN
authors.lastname: Gibson
authors.forename: Janette M
authors.initials: JM
authors.lastname: Vincent
authors.forename: Tony
authors.initials: T
authors.lastname: Speer
authors.forename: Neil A
authors.initials: NA
authors.lastname: Collier
authors.forename: Keith
authors.initials: K
authors.lastname: Noack
mesh_terms: D001663:Bilirubin / Q000097:blood; D002758:Cholangiography / Q000379:methods; D002760:Cholangiopancreatography, Endoscopic Retrograde; D042883:Choledocholithiasis / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007458:Iodipamide / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media; C012386:meglumine iotroxinate; D001663:Bilirubin; D007458:Iodipamide