| In vitro characterization of perfluorocarbon droplets for focused ultrasound therapy. | |
| | |
MedLine Citation:
|
PMID: 20693614 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Focused ultrasound therapy can be enhanced with microbubbles by thermal and cavitation effects. However, localization of treatment is difficult as bioeffects can occur outside of the target region. Spatial control of bubbles can be achieved by ultrasound-induced conversion of liquid perfluorocarbon droplets to gas bubbles. This study was undertaken to determine the acoustic parameters for bubble production by droplet conversion and how it depends on the acoustic conditions and droplet physical parameters. Lipid-encapsulated droplets containing dodecafluoropentane were manufactured with sizes ranging from 1.9 to 7.2 microm in diameter and diluted to a concentration of 8 x 10(6) droplets mL(-1). The droplets were sonicated in vitro with a focused ultrasound transducer and varying frequency and exposure under flow conditions through an acoustically transparent vessel. The sonications were 10 ms in duration at frequencies of 0.578, 1.736 and 2.855 MHz. The pressure threshold for droplet conversion was measured with an active transducer operating in pulse-echo mode and simultaneous measurements of broadband acoustic emissions were performed with passive acoustic detection. The results show that droplets cannot be converted at low frequency without broadband emissions occurring. However, the pressure threshold for droplet conversion decreased with increasing frequency, exposure and droplet size. The pressure threshold for broadband emissions was independent of the droplet size and was 2.9, 4.4 and 5.3 MPa for 0.578, 1736 and 2.855 MHz, respectively. In summary, we have demonstrated that droplet conversion is feasible for clinically relevant sized droplets and acoustic exposures. |
| | |
Authors:
|
Kelly C Schad; Kullervo Hynynen |
Related Documents
:
|
3624634 - The application of a capacitive probe technique for direct observation of electromechan... 7462474 - Spontaneous narrowband acoustic signals emitted by human ears. 16411804 - Detection of hearing loss using 2f2-f1 and 2f1-f2 distortion-product otoacoustic emissi... 19015514 - Enhancement of sensitivity gain and frequency tuning by coupling of active hair bundles. 10627324 - Theory of small vertebral motions: an analytical model compared to data. 15246344 - Acclimation of haslea ostrearia to light of different spectral qualities - confirmation... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2010-08-06 |
Journal Detail:
|
Title: Physics in medicine and biology Volume: 55 ISSN: 1361-6560 ISO Abbreviation: Phys Med Biol Publication Date: 2010 Sep |
Date Detail:
|
Created Date: 2010-08-17 Completed Date: 2010-11-24 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 0401220 Medline TA: Phys Med Biol Country: England |
Other Details:
|
Languages: eng Pagination: 4933-47 Citation Subset: IM |
Affiliation:
|
Imaging Research, Sunnybrook Health Sciences Centre, 2075 Bayview Ave, Toronto, Ontario M4N 3M5, Canada. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Acoustics* Capsules / chemistry, pharmacology Fluorocarbons / chemistry*, pharmacology Gases Lipids / chemistry, pharmacology Solutions / chemistry* Time Factors Ultrasonic Therapy* |
| Chemical | |
Reg. No./Substance:
|
0/Capsules; 0/Fluorocarbons; 0/Gases; 0/Lipids; 0/Solutions; 678-26-2/perfluoropentane |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Determination of average LET of therapeutic proton beams using Al2O3:C optically stimulated luminesc...
Next Document: An investigation of the trade-off between the count level and image quality in myocardial perfusion ...