Carbon Dioxide Digital Subtraction Angiography: Everything You Need to Know and More

Automated CO2 angiography: Injection pressure and volume settings

The purpose of this work was to outline some practical rules for pressure and volume settings in automatic CO₂ injection angiographic procedures focusing on the iliac arterial system, since, in current clinical practice, each operator uses his personal experience to obtain imaging results which are not always easy to compare. A theoretical model was thus developed and then verified by a mechanical simulator of the aortoiliac vascular system, with constant and pulsatile blood flow. The conditions of forward and reverse flows have been described, both for constant and pulsatile regimens and pressures, flows, and optical images of the bubbles in glass vessels were simultaneously acquired, analyzed and compared. Our results demonstrated that "good" radiological images (adequate to patient's conditions and clinical need) are strictly related to appropriate settings of gas injection pressure and flow, in accordance with two simple operative rules. These rules prescribe that the patient's pressure, the blood flow in the vessel, and the hydraulic resistance of the gas injection line be known: the first two parameters may be estimated, while the third must be experimentally measured. By following these rules, it is possible to obtain the best results for each clinical setting, a more standardized approach and better imaging during angiographic procedures with carbon dioxide as contrast medium.

Physiology of Intraluminal Administration of Carbon Dioxide as a Contrast Medium

BACKGROUND

Carbon dioxide (CO2) exists in nature around us. In the middle of the 20th century, the intraluminal injection of CO2 demonstrated similar results to those of Digital Subtraction Angiography (DSA) with an iodinated contrast agent (ICA). Since then, the technology behind CO2 DSA has developed significantly.

OBJECTIVE

The aim of this study is to inform physicians about the unique properties of CO2 and its physiology after intraluminal injection.

METHODS

An extensive search for English literature on the properties of CO2 and the physiology of intraluminal administration was conducted using Pubmed.

RESULTS

There is sufficient literature on the properties of CO2 and the physiology of CO2 DSA. A review of this literature explains what happens to the human organism after the injection of CO2.

CONCLUSION

There is enough evidence that CO2 DSA is both effective, diagnostic and safe, but the properties of CO2 should be taken under consideration as complications occur, although rarely.