Principles, applications and projections of ultrasound contrast

Ultrasound contrast agents have evolved since their discovery in 1968, becoming safe and effective diagnostic tools thanks to their strictly intravascular nature and their ability to enhance ultrasound signals through stabilized gas microbubbles. This review explores their mechanisms of action, physical principles, chemical structure, and main clinical applications. The nonlinear oscillation of microbubbles under ultrasound and their controlled fragility enables real-time visualization of microvascularization, supporting their use in the diagnosis of various lesions and in image-guided interventional procedures. Their potential in pediatrics is also noteworthy, as their safety profile has expanded their use to new indications such as vesicoureteral reflux and blunt abdominal trauma. Despite certain limitations in sensitivity or anatomical resolution compared to other imaging techniques, contrast-enhanced ultrasound represents a non-invasive, radiation-free alternative with a promising future in both diagnostic and potential therapeutic applications.