Linked Life Data

16471440

Source:http://linkedlifedata.com/resource/pubmed/id/16471440

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2006-2-13
pubmed:abstractText
Ultrasound contrast agents (UCA), created originally for visualization and diagnostic purposes, recently have been suggested as efficient enhancers of ultrasonic power deposition in tissue. The ultrasonic energy absorption by the contrast agents, considered as problematic in diagnostic imaging, might have beneficial impact in therapeutic applications such as targeted hyperthermia-based or ablation treatments. Introduction of gas microbubbles into the tissue to be treated can improve the effectiveness of current treatments by limiting the temperature rise to the treated site and minimizing the damage to the surrounding healthy tissues. To this end, proper assessment of the governing parameters of energy absorption by ultrasonically induced stabilized bubbles is important for both diagnostic and therapeutic ultrasound applications. The current study was designed to predict theoretically and measure experimentally the dissipation and heating effects of encapsulated UCA in a well-controlled and calibrated environment. The ultrasonic effects of the microbubble concentration, transmitted intensity, and frequency on power dissipation and stability of the UCA have been studied. The maximal temperature elevation obtained during 300 s experiments was 21 degrees C, in a 10 ml volume target containing UCA, insonifled by unfocused 3.2 MHz continuous wave (CW) at spatial average intensity of 1.1 W/cm2 (182 kPa). The results also suggest that higher frequencies are more efficiently absorbed by commonly used UCA. In particular, for spatial average intensity of 1.1 W/cm2 and concentration of 5 x 10(6) microspheres/cm3, no significant reduction of UCA absorption was noticed during the first 150 s for insonation at 3.2 MHz and the first 100 s for insonation at 1 MHz. In addition, when lower average intensity of 0.5 W/cm2 (160 kPa) at 3.2 MHz was used, the UCA absorptivity sustained for almost 200 s. Thus, when properly activated, UCA may be suitable for localized hyperthermic therapies.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0885-3010
pubmed:author
pubmed:issnType
Print
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
137-47
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Enhanced heat deposition using ultrasound contrast agent--modeling and experimental observations.
pubmed:affiliation
Department of Biomedical, Technion-Israel Institute of Technology, Haifa 32000, Israel. danir@tx.technion.ac.il
pubmed:publicationType
Journal Article, Comparative Study, Evaluation Studies