Bubble contrast, formally known as ultrasound contrast agent, consists of microscopic gas-filled bubbles, typically 1 to 10 micrometers in diameter, encapsulated in a thin shell of protein, lipid, or polymer. When injected intravenously, these microbubbles circulate through the bloodstream and strongly reflect ultrasound waves, dramatically enhancing the visibility of blood vessels and blood flow on the ultrasound image. Contrast-enhanced ultrasound is increasingly used to characterize liver lesions, evaluate cardiac perfusion, detect vesicoureteral reflux in children, and assess organ transplant viability. Unlike CT and MRI contrast agents, ultrasound contrast does not affect the kidneys and is not associated with allergic reactions to iodine.
Sonography Term