title: Upper-extremity venography: CO2 versus iodinated contrast material.
abstract: OBJECTIVE
  To determine prospectively the diagnostic performance of CO(2) venography, by using conventional venography with iodinated contrast material as the reference standard, for the preoperative evaluation of upper-limb and central veins before creation of fistulas for hemodialysis access.
  
  
  METHODS
  The study was approved by the institutional review board, and informed consent was obtained from all patients. Twenty-two patients underwent comparative CO(2) and conventional venography of upper-extremity and central veins. Two independent observers evaluated the opacification of the veins and grade of stenosis, if present. Interobserver agreements were estimated with the Cohen kappa coefficient. Calculations of sensitivity, specificity, and accuracy were used for intertechnique observations.
  
  
  RESULTS
  For CO(2) venography, global interobserver agreement was good, with a kappa value of 0.90 (range, 0.71-1.00; 95% confidence interval: 0.84, 0.95). A kappa value of 0.96 (range, 0.86-1.00; 95% confidence interval: 0.93, 0.99) was calculated for global interobserver agreement for conventional venography. The sensitivity, specificity, and accuracy of CO(2) venography for all vein segments were 97%, 85%, and 95%, respectively.
  
  
  CONCLUSIONS
  CO(2) venography had a sensitivity of 97% and a specificity of 85% in the assessment of upper-limb and central vein patency and stenosis, with conventional venography used as the reference standard.
authors.affiliation: Department of Radiology, University Hospitals Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium. sam.heye@uz.kuleuven.ac.be
authors.forename: Sam
authors.initials: S
authors.lastname: Heye
authors.forename: Geert
authors.initials: G
authors.lastname: Maleux
authors.forename: Guy J
authors.initials: GJ
authors.lastname: Marchal
mesh_terms: D000368:Aged; D001132:Arm / Q000098:blood supply*; D001166:Arteriovenous Shunt, Surgical; D002245:Carbon Dioxide; D003287:Contrast Media; D005260:Female; D006801:Humans; D007472:Iohexol; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010690:Phlebography / Q000379:methods*; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D002245:Carbon Dioxide; D007472:Iohexol