Format

Send to:

Choose Destination
See comment in PubMed Commons below
Ultrasound Med Biol. 2013 Mar;39(3):449-65. doi: 10.1016/j.ultrasmedbio.2012.09.004. Epub 2013 Feb 4.

Probability of cavitation for single ultrasound pulses applied to tissues and tissue-mimicking materials.

Author information

  • 1Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA. adamdm@umich.edu

Abstract

In this study, the negative pressure values at which inertial cavitation consistently occurs in response to a single, two-cycle, focused ultrasound pulse were measured in several media relevant to cavitation-based ultrasound therapy. The pulse was focused into a chamber containing one of the media, which included liquids, tissue-mimicking materials, and ex vivo canine tissue. Focal waveforms were measured by two separate techniques using a fiber-optic hydrophone. Inertial cavitation was identified by high-speed photography in optically transparent media and an acoustic passive cavitation detector. The probability of cavitation (P(cav)) for a single pulse as a function of peak negative pressure (p(-)) followed a sigmoid curve, with the probability approaching one when the pressure amplitude was sufficient. The statistical threshold (defined as P(cav) = 0.5) was between p(-) = 26 and 30 MPa in all samples with high water content but varied between p(-) = 13.7 and >36 MPa in other media. A model for radial cavitation bubble dynamics was employed to evaluate the behavior of cavitation nuclei at these pressure levels. A single bubble nucleus with an inertial cavitation threshold of p(-) = 28.2 megapascals was estimated to have a 2.5 nm radius in distilled water. These data may be valuable for cavitation-based ultrasound therapy to predict the likelihood of cavitation at various pressure levels and dimensions of cavitation-induced lesions in tissue.

Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

PMID:
23380152
[PubMed - indexed for MEDLINE]
PMCID:
PMC3570716
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Write to the Help Desk