CO2 microbubble contrast enhancement in x-ray angiography.

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Radiology

Background:

• Conventional contrast agents for x-ray examinations can have limitations.
• Carbon dioxide (CO2) gas has been explored as an alternative contrast agent.
• Microbubble contrast agents offer unique properties for imaging.

Purpose of the Study:

• To evaluate the efficacy of carbon dioxide (CO2) microbubble contrast enhancement for depicting blood vessels in x-ray examinations.
• To demonstrate the feasibility of generating CO2 microbubbles for enhanced vascular visualization.

Main Methods:

• CO2 microbubbles were generated using an ejector-type generator by cavitating saline with CO2 gas.
• Optimal input pressures for microbubble generation were determined in a phantom study.
• Angiography was performed in swine using CO2 microbubbles, conventional CO2 gas, and iodinated contrast media.

Main Results:

• Specific input pressures (0.16 MPa for saline, 0.5 MPa for CO2 gas) yielded abundant CO2 microbubbles.
• Interventional radiologists confirmed visualization of arteries with CO2 microbubbles, conventional CO2, and iodinated contrast.
• Digital values in vessels enhanced with CO2 microbubbles were significantly higher than background levels.

Conclusions:

• CO2 microbubble contrast enhancement is effective for depicting blood vessels in x-ray angiography.
• The generation of a high concentration of CO2 microbubbles within blood vessels facilitates visualization.
• This technique presents a viable option for contrast enhancement in radiographic procedures.