Photoacoustic Impulse Response of Lipid-Coated Ultrasound Contrast Agents

IEEE Trans Ultrason Ferroelectr Freq Control. 2021 Jun;68(6):2311-2314. doi: 10.1109/TUFFC.2021.3052140. Epub 2021 May 25.

Abstract

The utility of ultrasound imaging and therapy with microbubbles may be greatly enhanced by determining their impulse-response dynamics as a function of size and composition. Prior methods for microbubble characterization utilizing high-speed cameras, acoustic transducers and laser-based techniques typically scan a limited frequency range. Here, we report on the use of a novel photoacoustic technique to measure the impulse response of single microbubbles. Individual microbubbles are driven with a broadband photoacoustic wave generated by a nanosecond-pulse laser illuminating an optical absorber. The resulting microbubble oscillations were detected by following transmission of a second laser as it passes twice through the microbubble. The system could even resolve oscillations resulting from a single-shot. As a proof-of-concept study, the size-dependent, linear impulse response of lipid-coated microbubbles was characterized using this technique. This unique method of microbubble characterization with exceptional spatiotemporal resolution opens new avenues for capturing and analyzing microbubble system dynamics.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acoustics
  • Contrast Media*
  • Lipids
  • Microbubbles*
  • Ultrasonography

Substances

  • Contrast Media
  • Lipids