title: Carbon dioxide-based portography: an alternative to conventional imaging with the use of iodinated contrast medium.
abstract: OBJECTIVE
  To clarify the efficacy of carbon dioxide (CO(2)) as a contrast material to evaluate portal vein images by percutaneous transhepatic portography (PTP).
  
  
  METHODS
  Twenty patients (38-76 years; male 13, female 7) with chronic liver diseases were the subjects of this prospective study. Portal venous opacification by PTP was compared between CO(2)-based images and iodinated contrast medium (ICM)-based images by two independent reviewers, according to the three-grade scoring; 0 for none, 1 for weak and 2 for sufficient.
  
  
  RESULTS
  Total scores of extrahepatic portal veins (137 for CO(2), 93 for ICM), collateral vessels (64 for CO(2), 60 for ICM) and intrahepatic portal veins (69 for CO(2), 76 for ICM) were not statistically significant between CO(2)-based and ICM-based images (P = 0.0623). Sufficient opacification of superior mesenteric vein was more frequent on CO(2)-based images (none 0, weak 4, sufficient 16) than ICM-based images (none 19, weak 0, sufficient 1; P < 0.0001). The score was not statistically significant between CO(2)-based and ICM-based images in portal trunk, splenic vein, inferior mesenteric vein and other collateral vessels. Although opacification grade in the intrahepatic left portal vein was not statistically significant between CO(2)-based and ICM-based images (P = 0.1515), weak opacification was significantly frequent on CO(2)-based images (weak 10, sufficient 10) compared to ICM-based images (weak 0, sufficient 20; P = 0.0003) in the intrahepatic right portal vein. Inter-reviewer agreement was excellent between the two reviewers for CO(2)-based images (kappa = 0.913) and ICM-based images (kappa = 0.924).
  
  
  CONCLUSIONS
  Carbon dioxide may be a first-line contrast material for evaluating portal vein images by PTP.
authors.affiliation: Department of Medicine and Clinical Oncology, Chiba University Graduate School of Medicine, Chiba, Japan. maru-cib@umin.ac.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Maruyama
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Okugawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ishibashi
authors.forename: Masanori
authors.initials: M
authors.lastname: Takahashi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Yoshizumi
authors.forename: Osamu
authors.initials: O
authors.lastname: Yokosuka
mesh_terms: D000328:Adult; D000368:Aged; D002245:Carbon Dioxide / Q000008:administration & dosage; D003287:Contrast Media / Q000008:administration & dosage*; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006975:Hypertension, Portal / Q000000981:diagnostic imaging*; D007275:Injections, Intravenous; D007472:Iohexol / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D011169:Portal Vein / Q000000981:diagnostic imaging*; D011172:Portography / Q000379:methods*; D011446:Prospective Studies; D015203:Reproducibility of Results
chemical_list: D003287:Contrast Media; D002245:Carbon Dioxide; D007472:Iohexol