Document Detail


Spontaneous homogeneous nucleation, inertial cavitation and the safety of diagnostic ultrasound.
MedLine Citation:
PMID:  12467862     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Gas bubbles of sufficient size to serve as cavitation nuclei may form spontaneously in tissue in regions of very low interfacial tension. In the absence of an acoustic wave or other mechanical stress, such nuclei will quickly dissolve and disappear from the medium. Under the influence of an acoustic wave, however, these microbubbles may grow to many times their initial size and then collapse violently, a process known as inertial cavitation. In this work, the in vivo energetics and dynamics of the nucleation-cavitation process were modeled by treating tissue as a homogeneous fluid. The assumption of a viscosity of 10(-3) Pa s (i.e., that of water) resulted in the lowest acoustic rarefactional pressure threshold for nucleation-cavitation events, approximately 4.0 MPa, which was essentially frequency-independent over the range 1 to 15 MHz. The rarefactional pressure threshold for a viscosity of 5 x 10(-3) Pa s (that of blood) also was approximately 4.0 MPa at 1 MHz, but the threshold for this higher viscosity increased nearly linearly with frequency above approximately 5 MHz, never being more than approximately 0.2 MPa below the equivalent derated peak rarefactional pressure calculated assuming MI = 1.9, the current USFDA guideline.
Authors:
Charles C Church
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Ultrasound in medicine & biology     Volume:  28     ISSN:  0301-5629     ISO Abbreviation:  Ultrasound Med Biol     Publication Date:  2002 Oct 
Date Detail:
Created Date:  2002-12-06     Completed Date:  2003-04-24     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0410553     Medline TA:  Ultrasound Med Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  1349-64     Citation Subset:  IM    
Affiliation:
Acusphere, Inc., 500 Arsenal Street, Watertown, MA, USA. cchurch@olemiss.edu
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MeSH Terms
Descriptor/Qualifier:
Biomechanics
Humans
Safety
Ultrasonography / adverse effects*
Grant Support
ID/Acronym/Agency:
R37CA39230-28/CA/NCI NIH HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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