Pressure responses of different lipid-shelled microbubbles: A perspective on pressure dependent stability and subharmonic response

Le résumé fourni par la source

Microbubbles are widely used as ultrasound contrast agents because of their high echogenicity and nonlinear oscillatory behaviors. Under sufficiently strong acoustic excitations, they generate multiple harmonic components, including a subharmonic response. The subharmonic exhibits a strong correlation with ambient pressure, whereas the fundamental and second harmonics show little to no sensitivity. In this study, we investigate the characteristics and pressure-dependent behaviors of several microbubble formulations. These include commercially available polydisperse contrast agents, such as Definity, Sonazoid, and SonoVue, a new monodisperse agent, and polydisperse microbubbles produced in-house containing different gases (SF6, C3F8, and C4F10). Each microbubble type was characterized by attenuation and size measurements. We developed a new optical microscopy imaging setup to observe the stability of these microbubbles under static overpressure. Finally, we measured the ambient pressure sensitivity of subharmonic responses from each microbubble type. The findings offer new insights into the stability and pressure-dependent behaviors of different classes of microbubbles, which are critical for further development of subharmonic-aided pressure estimation (SHAPE).

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.