title: Accuracy of CO(2) angiography in vessel diameter assessment: a comparative study of CO(2) versus iodinated contrast material in a porcine model.
abstract: OBJECTIVE
  To compare, with use of intravascular ultrasound (IVUS) as an internal reference standard in a porcine model, arterial diameters measured from arteriograms obtained with use of CO(2) to those obtained with use of iodinated contrast material (ICM).
  
  
  METHODS
  In nine pigs, digital subtraction angiograms (DSAs) were obtained in the aorta and iliac arteries to compare vessel diameters measured with use of CO(2) to those measured with use of ICM. These measurements were divided by measurements made with use of intravascular ultrasound (IVUS) to yield a DSA/IVUS ratio. Differences between ICM and CO(2) were compared with analysis of variance to assess the effect of location (aorta vs iliac), contrast material used (ICM vs CO(2)), and position (posteroanterior, right anterior oblique, or left anterior oblique). Secondary analysis compared measurements of dependent and nondependent iliac arteries and compared the use of hand-injected CO(2) to that of CO(2) injected by an injector.
  
  
  RESULTS
  The DSA/IVUS ratio was 70.7% +/- 4.4% with ICM use and 69.6% +/- 6.3% with CO(2) use, which did not represent a significant difference (P =.311). Animal position had no effect (P =.477). Underestimation was worse in the iliac arteries than in the aorta (67.4% +/- 1.5% vs 71.4% +/- 1.7%; P =.038). There was no difference in nondependent (P =.163) arteries, but CO(2) underestimated dependent iliac artery size more than ICM did (66.3% +/- 4.8% vs 70.3% +/- 5.4%; P =.051). Vessel diameter was underestimated more with the CO(2) injector than with hand-injected CO(2) (64.3% +/- 2.3% vs 71.7% +/- 1.7%; P <.0001).
  
  
  CONCLUSIONS
  There is no difference in diameter underestimation between CO(2) and ICM in this animal model. Hand-injection of CO(2) causes less underestimation of vessel diameter than does the CO(2) injector.
authors.affiliation: Department of Radiology, Indiana University School of Medicine, University Hospital Room 0279, 550 N. University Blvd., Indianapolis, IN 46202-5253, USA. gmclenna@iupui.edu
authors.forename: G
authors.initials: G
authors.lastname: McLennan
authors.forename: K P
authors.initials: KP
authors.lastname: Moresco
authors.forename: N H
authors.initials: NH
authors.lastname: Patel
authors.forename: A
authors.initials: A
authors.lastname: Trobridge
authors.forename: J
authors.initials: J
authors.lastname: Dreesen
authors.forename: J
authors.initials: J
authors.lastname: Tennery
authors.forename: R
authors.initials: R
authors.lastname: Seshadri
authors.forename: C S
authors.initials: CS
authors.lastname: Johnson
mesh_terms: D000792:Angiography / Q000379:methods*; D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000648:ultrastructure*; D002245:Carbon Dioxide; D003287:Contrast Media; D006168:Guinea Pigs; D007083:Iliac Artery / Q000000981:diagnostic imaging*; D007455:Iodine; D023421:Models, Animal; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D002245:Carbon Dioxide; D007455:Iodine