High frequency attenuation measurements of lipid encapsulated contrast agents

High frequency attenuation measurements of lipid encapsulated contrast agents.

A number of recent studies have indicated the potential of ultrasound contrast agent imaging at high ultrasound frequencies. However, the acoustic properties of microbubbles at frequencies above 10 MHz remain poorly understood at present. In this study we characterize the high frequency attenuation properties of (1) BR14, (2) BR14 that has been mechanically filtered (1 and 2 microm pore sizes) ...

Quantification of Ultrasound Contrast Agents Using High Frequency Ultrasound

Ultrasound contrast agents (UCAs) are small microbubbles filled with gas. Because of their scattering properties, UCAs enhance the diagnostic capabilities of ultrasonic imaging. UCAs are associated with therapeutic or enhancing therapeutic applications of ultrasound and with possible adverse bioeffects. Quantification of the in vivo concentration of microbubbles is therefore essential to establ...

Acoustic characterisation of ultrasound contrast agents at high frequency

Excitation of polymer-shelled contrast agents with high-frequency ultrasound.

Few experimental and complementary theoretical studies have investigated high-frequency (>20 MHz) nonlinear responses from polymer-shelled ultrasound contrast agents. Three polymer agents with different shell properties were examined for their single-bubble backscatter when excited with a 40 MHz tone burst. Higher-order harmonic responses were observed for the three agents; however, their occur...

In-situ Attenuation Corrections for Radiation Force Measurements of High Frequency Ultrasound With a Conical Target

Radiation force balance (RFB) measurements of time-averaged, spatially-integrated ultrasound power transmitted into a reflectionless water load are based on measurements of the power received by the RFB target. When conical targets are used to intercept the output of collimated, circularly symmetric ultrasound sources operating at frequencies above a few megahertz, the correction for in-situ at...