Abstract

Estimating the focal size and position of a high-intensity focused ultrasound (HIFU) transducer remains a challenge since traditional methods, such as hydrophone scanning or schlieren imaging, cannot tolerate high pressures, are directional, or provide low resolution. The difficulties increase when dealing with the complex beam pattern of a multielement HIFU transducer array, e.g., two transducers facing each other. In the present study we show a novel approach to the visualization of the HIFU focus by using shockwave-generated bubbles and a diagnostic B-mode scanner. Bubbles were generated and pushed by shock waves toward the HIFU beam, and were trapped in its pressure valleys. These trapped bubbles moved along the pressure valleys and thereby delineated the shape and size of the HIFU beam. The main and sidelobes of 1.1- and 3.5 MHz HIFU beams were clearly visible, and could be measured with a millimeter resolution. The combined foci could also be visualized by observing the generation of sustained inertial cavitation and enhanced scattering. The results of this study further demonstrate the possibility of reducing the inertial cavitation threshold by the local introduction of shock wave-generated bubbles, which might be useful when bubble generation and cavitation-related bioeffects are intended within a small region in vivo.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.