Destruction of Definity® Microbubbles Used for Ultrasound Imaging and Drug Delivery

Microbubble based contrast agents improves medical ultrasound images. Destruction of contrast agent Definity® (Bristol Meyer-Squibb Imaging, North Ballerina, MA) is studied using broadband attenuation technique. Single-cycle ultrasound pulses are sent through a bubble suspension at different pulse repetition frequencies (PRF) and pressure amplitudes. For each PRF, there is a critical pressure amplitude (~1.1–1.2MPa for 50, 100, 200 Hz PRFs studied), below which there is no evidence of bubble destruction. Above the critical pressure amplitudes the rate of destruction depends on PRF and pressure. But at high pressure amplitudes (e.g. 2.97 MPa) destruction becomes independent at higher PRFs.