Document Detail


Combination of thermal and cavitation effects to generate deep lesions with an endocavitary applicator using a plane transducer: ex vivo studies.
MedLine Citation:
PMID:  14962614     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In the high-intensity focused ultrasound (US), or HIFU, field, it is well-known that the cavitation effect can be used to induce lesions of larger volume. The principle is based on the increase in the equivalent attenuation coefficient of the tissue in the presence of the bubbles created by cavitation. The elementary lesions produced by combination of cavitation and thermal effects, using focused transducers, were spherical and developed upstream of the focal point. This paper presents a method that combines cavitation with a thermal effect to obtain deeper lesions using a plane transducer, rather than a focused one. The cavitation effect was produced by delivering intensities of 60 W/cm2 at the face of the transducer for 0.5 s. The applicator was then rotated through 90 degrees at a constant speed of between 0.5 and 1.5 degrees /s. During this rotation, ex vivo tissues were exposed continuously to an acoustic intensity of 14 W/cm2 to combine the cavitation effect with a thermal effect. The necroses were, on average, twice as deep when the cavitation effect was used as those obtained with a thermal effect alone. Observed macroscopically, the lesions have a very well-delimited geometry. Temperature measurements made at different angles of treatment have shown that they were coagulation necroses.
Authors:
David Melodelima; Jean Yves Chapelon; Yves Theillère; Dominique Cathignol
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Ultrasound in medicine & biology     Volume:  30     ISSN:  0301-5629     ISO Abbreviation:  Ultrasound Med Biol     Publication Date:  2004 Jan 
Date Detail:
Created Date:  2004-02-13     Completed Date:  2004-06-03     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0410553     Medline TA:  Ultrasound Med Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  103-11     Citation Subset:  IM    
Affiliation:
INSERM Unit 556, Lyon, France. melodelima@lyon.inserm.fr
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MeSH Terms
Descriptor/Qualifier:
Acoustics
Animals
Electronics, Medical
Equipment Design
Hot Temperature
Liver / pathology
Necrosis
Swine
Transducers
Ultrasonic Therapy / instrumentation,  methods*

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


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