Ultrasound Contrast Agents

Contrast agents are injected intravenously and, through the process of expansion and contraction, they create backscatter and reflection, allowing one to differentiate between the highly echogenic agent and surrounding tissues/fluids. They were first introduced in echocardiography, but their materials (ex: low density gases) caused them to be very soluble in blood. Our poster outlines the new generation contrast agents, their composition, and also how their physical properties/behaviors now allow the sonographer to image in live time for longer. With advancement in technology, new generation agents are being used in site-specific drug delivery. The drugs are incorporated within the bubble, and specific ligands are attached to the bubble, which then attach to receptors in the targeted area. The sonographer plays a very key role in this application and, through the use of higher acoustic powers, he/she is able to burst the bubble, delivering the drug. We further outline how microbubbles act as cavitation nuclei. Although there are many advantages to using contrast agents, there are also a few disadvantages, such as a rise in body temperature, or cell injury.

keywords: drug-delivery, contrast agents, microbubbles, cavitation nuclei, backscatter