Carbon Dioxide Angiography
Carbon dioxide (CO2) gas is used as an alternative contrast to iodinated contrast material. When injected into a blood vessel, carbon dioxide bubbles displace blood, allowing vascular imaging. Because of the lack of nephrotoxicity and allergic reactions, CO2 is increasingly used as a contrast agent for diagnostic angiography and vascular interventions.
CO2 is particularly useful in patients with renal insufficiency or a history of hypersensitivity to iodinated contrast medium. Also, it is safe as CO2 is effectively eliminated by means of respiration.
Disadvantage: CO2 is less dense than iodinated contrast medium, and the overall quality of the CO2 vascular image is less than the contrast medium.
Cautions:
- CO2 should not be used as a contrast agent in the coronary and cerebral circulations because of the possibility of adverse effects secondary to a gas embolism. Safely, CO2 should be avoided in vessels above the diaphragm.
- In patients with pulmonary insufficiency or pulmonary hypertension because of amount diagnostic doses of CO2 pulmonary arterial pressure may increase.
- In right-to-left shunts Co2 may cause paradoxical gas embolism.
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Carbon Dioxide Angiography - emedicine.com
