L. Yang et Ma. Bettmann, Identification of the portal vein: Wedge hepatic venography with CO2 or iodinated contrast medium, ACAD RADIOL, 6(2), 1999, pp. 89-93
Rationale and Objectives. The purpose of this study was to evaluate the uti
lity of CO2 versus iodinated contrast medium for wedge hepatic venography i
n identifying portal vein anatomy during transjugular intrahepatic portosys
temic shunt (TIPS) procedures.
Materials and Methods. Wedge hepatic venograms obtained with CO2 or iodinat
ed contrast medium and direct portograms of 43 patients undergoing TIPS pro
cedures were analyzed retrospectively, Wedge venography was performed in 23
patients with CO2 and in 21 with iodinated contrast medium; direct portogr
aphy was subsequently performed in 42 of 44 patients with iodinated contras
t medium and in one with CO2. All cases were reviewed systematically to com
pare portal vein anatomy and completeness of anatomic identification betwee
n direct portography and wedge venography, and the results with CO2 were co
mpared to those with iodinated contrast material.
Results. On the basis of opacification of the main portal trunk, branches,
or both, the portal vein appearance (definition of the portal bifurcation)
was good to excellent in 21 of 23 patients imaged with CO2 but in only two
of 20 patients imaged with iodinated contrast medium. Wedge venograms agree
d with direct portograms in 91% (21 of 23) of the CO2 cases and in 10% (two
of 20) of the iodinated contrast medium cases. The two patients with poor
opacification using CO2 had poor delineation of the main portal trunk, bran
ches, and varices. TIPS could not be created in three patients, In two, abn
ormal morphology was identified at CO2 venography; in the third, wedge veno
graphy was not performed,
Conclusion. Wedge hepatic venography with CO2 compared with iodinated contr
ast medium has a substantially higher likelihood of correctly and completel
y identifying the location and anatomy of the portal vein.