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BRL Abstracts Database |
Your search for ultrasound produced 3296 results. Page 92 out of 330
Title |
Distortions of ultrasonic field introduced by the rib cage in echocardiography. |
Author |
Savakus AD, Shung KK, Miller NB. |
Journal |
J Clin Ultrasound |
Volume |
|
Year |
1982 |
Abstract |
In ultrasonic examination of the heart, the anatomy and motion of heart structures can be observed by placing the ultrasonic transducer over an intercostal window adjacent to the sternum. The ultrasonic beam may be reflected, refracted, or scattered from its path by the ribs and soft tissues before reaching the target of interest. This interaction between the tissues and ultrasound beam, which introduces significant changes in ultrasonic beam characteristics, may result in considerable degradation of the lateral resolution of the ultrasonic system, determined largely by the beam width. In this paper, the effect of rib cage on the beam characteristics is examined. It is shown that the rib cage can produce severe distortions of the ultrasonic beam, namely, asymmetry in beam cross-section, alteration in beam diameter, and deflection of the beam from its central path. It is also demonstrated that this distortion is dependent upon transducer diameter, width of the intercostal window, and transducer angulation relative to the breast plate. |
Title |
Divergent beam ultrasound computed tomography for differential thermography. |
Author |
Haney MJ. |
Journal |
Thesis(PhD): Univ of Illinois |
Volume |
|
Year |
1985 |
Abstract |
The applications of divergent beam ultrasound computed tomography for noninvasively estimating temperature change in biological tissue were examined. This study was prompted by the recognition that both ultrasound speed of propagation and frequency dependent attenuation (two physical properties measurable by ultrasound tomography) are temperature sensitive. Speed generally increases with temperature, and attenuation coefficient generally decreases with temperature, for nonfatty tissue. |
Title |
DNA damage from pulsed sonication of human leukocytes in vitro. |
Author |
Pinamonti S, Caruso A, Mazzeo N, Zebini E, Rossi A. |
Journal |
IEEE Trans UFFC |
Volume |
|
Year |
1986 |
Abstract |
Pulsed echo sonication of human leukocytes in vitro results in a delayed response to the PHA reproductive stimulus and in damage to the DNA. The electrophoretic mobility, the sensitivity to nuclease S1 and the electron microscopy analysis of the DNA isolated from sonicated cells strongly suggest that pulsed ultrasound caused in vitro single strand breaks in DNA. |
Title |
DNA-loaded albumin microbubbles enhance ultrasound-mediated transfection in vitro. |
Author |
Frenkel PA,Chen S,Thai T,Shohet RV,Grayburn PA. |
Journal |
Ultrasound Med Biol |
Volume |
|
Year |
2002 |
Abstract |
Ultrasound (US), with or without microbubbles, enhances gene transfer in cultured cells, but the effect is modest. We tested if attaching DNA to albumin microbubbles during bubble synthesis could enhance gene expression. Plasmid DNA was loaded on the albumin shell over a range of concentrations (500 to 10,000 µg/mL). Optimal gene expression occurred with loading doses of 4000 µg DNA/mL (4k-loaded bubbles). These microbubbles had diameters of 2.4 +/- 0.7 µm and carried 40 pg DNA/microbubble. DNA-loaded microbubbles had optimal transfection at higher delivered doses of DNA than unloaded bubbles mixed with plasmid. The 4k-loaded bubbles demonstrated a fivefold (p = 0.0003) increase in luciferase reporter expression over that with unloaded bubbles. Similarly, transfection efficiency was better for 4k-loaded microbubbles than unloaded microbubbles (41 +/- 3% vs. 9 +/- 3%, p < 0.0001). DNA loading of microbubbles enhances gene expression and transfection efficiency in US-targeted transfection in vitro and may represent an improved avenue for therapeutic gene delivery in vivo. |
Title |
Doctor advises training in use of ultrasound. |
Author |
Unknown. |
Journal |
Burlington Free Press |
Volume |
|
Year |
1981 |
Abstract |
No abstract available. |
Title |
Doctors question ultrasound. |
Author |
Unknown. |
Journal |
Chicago Sun-Times |
Volume |
|
Year |
1982 |
Abstract |
No abstract available. |
Title |
Doctors questioning cost, safety of ultrasound. |
Author |
Wolinsky H. |
Journal |
Chicago Sun-Times |
Volume |
|
Year |
1982 |
Abstract |
No abstract available. |
Title |
Does ointment plus ultrasound clear genital herpes? |
Author |
Unknown. |
Journal |
Med World News |
Volume |
|
Year |
1978 |
Abstract |
No abstract available. |
Title |
Does prenatal sonography affect intellectual performance? |
Author |
Kieler H, Haglund B, Cnattingius S, Palmgren J, Axelsson O. |
Journal |
Epidemiology |
Volume |
|
Year |
2005 |
Abstract |
BACKGROUND:
Little is known about potential risks of ultrasound during pregnancy. The developing brain is susceptible to environmental influences, and prenatal ultrasound has been reported to affect cognitive abilities in animals.
METHODS:
To assess a possible association between prenatal ultrasound and intellectual performance, we studied men born in Sweden from 1973 to 1978 who enrolled for military service from 1991 to 1996. Intellectual scores (mean +/- standard deviation = 5 +/- 2) were measured by a test battery at enrollment, and subnormal performance was defined as a score of 3 or less. We estimated differences in mean intellectual score between ultrasound-exposed and ultrasound-unexposed using linear regression, and we calculated relative risks of subnormal performance using logistic regression analysis.
RESULTS:
There were 7999 eligible men born in a hospital (Malmo) that included ultrasound scanning in standard antenatal care (exposed) and 197,829 men born in hospitals without ultrasound scanning programs (unexposed). We found lower intellectual performance scores (mean difference = -0.16; 95% confidence interval = -0.21 to -0.11) and an increased risk of subnormal performance (odds ratio = 1.28; CI = 1.18 to 1.38) among ultrasound-exposed compared with unexposed. However, men born in Malmo before scanning was introduced also had lower scores, and the decrease in test scores after the introduction of ultrasound was small. Moreover, we found no differences in intellectual performance within pairs of brothers as a result of ultrasound exposure.
CONCLUSIONS:
This study failed to demonstrate a clear association between ultrasound scanning and intellectual performance. |
Title |
Does ultrasound induce sister chromatid exchanges? |
Author |
Miller MW. |
Journal |
Ultrasound Med Biol |
Volume |
|
Year |
1985 |
Abstract |
No abstract available. |
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