title: Carbon dioxide contrast agent for CT arteriography: results in a porcine model.
abstract: OBJECTIVE
  To test the feasibility of carbon dioxide (CO(2))-enhanced computed tomographic (CT)-arteriography in an animal model.
  
  
  METHODS
  Five domestic swine underwent digital subtraction angiography (DSA), conventional CT angiography with iodinated contrast material, and CO(2)-enhanced CT arteriography. For each CO(2)-enhanced DSA image series, 100 mL of pressurized CO(2) was injected at 1.3 bar. CT imaging was performed according to a standardized scan protocol (2 x 32 x 0.6 mm; 120 kV, 210 mAs(eff), 330 msec gantry rotation time). Iodinated contrast material was administered intravenously according to a biphasic injection protocol. For CO(2)-enhanced CT arteriography, CO(2) was administered intraarterially via a catheter placed in the juxtarenal aorta. An injection pressure of 0.65 bar (volume flow rate, 7.5 mL/sec) was applied. Images were assessed visually by two observers on a four-point grading scale. Absolute intraarterial attenuation values were measured.
  
  
  RESULTS
  Image quality was rated to be the best for standard DSA. CO(2)-enhanced DSA was rated slightly superior to CO(2)-enhanced CT arteriography. No examination was considered to be nondiagnostic. The average multislice spiral CT (MSCT) scan duration was 7.9 sec +/- 0.6. The average amount of gas required for CO(2)-enhanced CT arteriography was 104 mL +/- 4, compared with 400 mL for CO(2)-enhanced DSA. Absolute attenuation values were significantly higher with CO(2)-enhanced CT arteriography (aorta, -928 HU +/- 39) than with standard CT angiography (490 HU +/- 40; P < .0001).
  
  
  CONCLUSIONS
  CO(2)-enhanced CT arteriography is feasible. In a porcine model, this technique is capable of depicting the aortoperipheral vessels down to the lower limb. These results warrant further studies of the diagnostic value of CO(2)-enhanced MSCT arteriography for the detection of arterial pathologic processes.
authors.affiliation: Department of Diagnostic Radiology, University Hospital, RWTH Aachen University, Pauwelsstrasse 30, Aachen, Germany. mahnken@rad.rwth-aachen.de
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Mahnken
authors.forename: Philipp
authors.initials: P
authors.lastname: Bruners
authors.forename: Gottfried
authors.initials: G
authors.lastname: Mommertz
authors.forename: Georg
authors.initials: G
authors.lastname: Mühlenbruch
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Jacobs
authors.forename: Rolf W
authors.initials: RW
authors.lastname: Günther
authors.forename: Stephan
authors.initials: S
authors.lastname: Langer
mesh_terms: D000792:Angiography / Q000379:methods*; D015901:Angiography, Digital Subtraction; D000818:Animals; D001027:Aortography; D002245:Carbon Dioxide / Q000008:administration & dosage*; D003287:Contrast Media; D005240:Feasibility Studies; D005263:Femoral Artery / Q000000981:diagnostic imaging; D007083:Iliac Artery / Q000000981:diagnostic imaging; D007261:Infusions, Intra-Arterial; D007275:Injections, Intravenous; D007472:Iohexol / Q000008:administration & dosage / Q000031:analogs & derivatives; D035002:Lower Extremity / Q000098:blood supply; D023421:Models, Animal; D015203:Reproducibility of Results; D034421:Sus scrofa; D036542:Tomography, Spiral Computed
chemical_list: D003287:Contrast Media; D002245:Carbon Dioxide; D007472:Iohexol; C038192:iopromide