| Analysis of Index Modulation of Doppler Microembolic Signals Part II: In Vitro Discrimination. | |
| | |
MedLine Citation:
|
PMID: 21144961 Owner: NLM Status: In-Data-Review |
Abstract/OtherAbstract:
|
The purpose of this study was to validate through experiments that frequency modulation (FM) of microembolic signatures was principally due to the radiation force. Several experiments were required to prove that such a frequency modulation originates from microdisplacements induced by the radiation force acting on microbubbles. The first experiment was performed to verify that the diffraction effects due to the presence of a skull did not disturb the acoustic field appreciably and to validate that a radiation force in the brain was sufficient to create a detectable microdisplacement. A second in vitro experiment using a single gate transcranial Doppler (TCD) system was conducted to show discrimination feasibility and to check that microembolic frequency modulation signatures (FMS) and frequency modulation index (FMI) were the same as those observed in vivo and those calculated by simulation. A final in vitro experiment was performed using a multigate multichannel TCD system to confirm the second experiment by directly measuring the microdisplacement induced by the radiation force. A new parameter, to be known as the position modulation index (PMI), is proposed. We showed that the radiation force is sufficient to induce detectable microdisplacements despite the presence of the skull. We also showed that the diffraction effects due to the skull induced a decrease in the ultrasound beam of 7.6 dB. Finally, we showed by using FMI and PMI that it is possible to discriminate gaseous from formed elements (<100 microns) despite the presence of the skull. The discrimination based on the FMI is an off-line technique allowing the analysis of standard TCD recordings. However, discrimination based on the PMI requires recordings obtained exclusively from a multi-gate system. (E-mail: jean-marc.girault@univ-tours.fr). |
| | |
Authors:
|
Jean-Marc Girault; Denis Kouamé; Sébastien Ménigot; Francesco Guidi; Grégrory Souchon; Jean-Pierre Remenieras |
Publication Detail:
|
Type: Journal Article |
Journal Detail:
|
Title: Ultrasound in medicine & biology Volume: 37 ISSN: 1879-291X ISO Abbreviation: Ultrasound Med Biol Publication Date: 2011 Jan |
Date Detail:
|
Created Date: 2010-12-14 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 0410553 Medline TA: Ultrasound Med Biol Country: England |
Other Details:
|
Languages: eng Pagination: 102-11 Citation Subset: IM |
Copyright Information:
|
Copyright © 2011 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved. |
Affiliation:
|
Université François Rabelais de Tours, UMRS "Imaging and Brain" U930 and CNRS ERL 3106, Tours, France. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Examining and analyzing subcellular morphology of renal tissue treated by histotripsy.
Next Document: Design and characterization of targeted ultrasound microbubbles for diagnostic use.