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BRL Abstracts Database |
Your search for ultrasound produced 3296 results. Page 263 out of 330
Title |
The physics of breast echography. |
Author |
Kossoff G, Jellins J. |
Journal |
Semin Ultrasound |
Volume |
|
Year |
1982 |
Abstract |
No abstract available. |
Title |
The possibility of genetic hazard from ultrasonic radiation. |
Author |
Thacker J. |
Journal |
Curr Top Radiat Res Q |
Volume |
|
Year |
1973 |
Abstract |
Ultrasound can degrade DNA in solution, and it is reported to cause chromosome breakage and genetic effects. The increasing use of ultrasound in medicine has prompted this review of the evidence for a genetic hazard in such applications. Consideration of the possible mechanisms for reported effects suggests that disruption of the genetic material in vivo arises as a part of general intracellular disruption and cell death. Positive genetic effects have been reported, but the most convincing of these are at apparently high intensities of irradiation where it is difficult or impossible to exclude heat shock. While certain interactions of ultrasound and tissue resulting in mutagenesis can be envisaged, and there is a need for study of genetic effects on appropriate multicellular organisms, the present evidence does not point to a high risk of such effects from the medical applications of ultrasound. Despite some claims to the contrary, it would seem that current diagnostic procedures are very unlikely to result in a genetic hazard. |
Title |
The possibility of harmful biological effects in ultrasonic diagnosis. |
Author |
Wells PN. |
Journal |
Proc Int Symp Janssen Pharm |
Volume |
|
Year |
1973 |
Abstract |
The conditions which justify the use of ultrasound to obtain diagnostic information are considered. The factors which specify the physical characteristics of ultrasonic irradiation are enumerated, and the mechanisms of ultrasonically induced effects in living systems are discussed. Published data are reviewed particularly with respect to the frequency dependence of biological effects, the cumulative effects of pulsed irradiation, and intensity-time relationships in biological effects. Epidemiological data are mentioned. Recommendations are made of conditions which seem to be ?safe?, outside which ultrasonic diagnosis should not be permitted. |
Title |
The possibility of harmful effects in using ultrasound for medical diagnosis. |
Author |
Connolly C, Pond J. |
Journal |
Biomed Eng |
Volume |
|
Year |
1967 |
Abstract |
There are undoubtedly several mechanisms by which ultrasonic radiation may affect animal tissue. Moreover, experience in X-radiology has shown that is unwise to assume that absence of immediate effects always implies that no damage has occurred. In this paper the authors consider the character of the ultrasonic disturbance, indicate a logical approach to the question of damage mechanisms, discuss some research pertinent to ultrasonic damage, and finally outline theoretical treatment of a mechanism-tissue shearing stress-which may be a very important factor in the production of biological damage even at diagnostic levels of ultrasound. |
Title |
The possibility of hazard in medical and industrial applications of ultrasound. |
Author |
Hill CR |
Journal |
Br J Radiol |
Volume |
|
Year |
1968 |
Abstract |
No abstract available. Publication Type: Review |
Title |
The possibility of measuring the coefficient of ultrasound attenuation in a one-side accessible layered medium. |
Author |
Mansfel'd AD, Reiman AM. |
Journal |
Acoustical Physics |
Volume |
|
Year |
2011 |
Abstract |
The possibility of measuring the ultrasound attenuation coefficient and its frequency dependence in a one-side accessible medium is considered under the assumption that the medium contains reflectors with unknown reflection coefficients and the measurements are performed in the reflection geometry. The possibility of measuring the reflection coefficients themselves is indicated. All the above parameters can be measured even when the reflector has the form of a layered structure. |
Title |
The potential of transskull ultrasound therapy and surgery using the maximum available skull surface area. |
Author |
Sun J, Hynynen K. |
Journal |
J Acoust Soc Am |
Volume |
|
Year |
1999 |
Abstract |
Based on previous studies, the transskull ultrasound field is re-examined by utilizing the maximum available skull surface area. The source is assumed to be in direct contact with the skull outer surface, and phase correction is adopted to obtain a sharp focus at a desired location. A digitized skull profile was obtained from Magnetic Resonance (MR) scan images of a volunteer. Two driving frequencies (0.5 and 1.0 MHz) within the appropriate frequency range for transskull ultrasound therapy and surgery are investigated. With no phase correction, there is no apparent transskull focus. With phase correction, a sharp transskull focus is obtained at the desired location. Both pressure and specific absorption rate (SAR) gains (ratios of pressure amplitude and SAR at the focal point compared to those on the outer skull surface) are examined, and it is shown that the skull heating problem can be overcome by utilizing the maximum available skull surface area. By specifying the phase correction for different locations, the focus can be successfully moved inside the deep brain volume without significantly compromising the pressure and SAR gains; however, the sidelobes may be of concern at superficial sites. |
Title |
The potential of ultrasound visualization for detecting the presence of abnormal structures within the female breast. |
Author |
Kelly-Fry E, Kossoff G, Hindman HA Jr. |
Journal |
Proc Ultrason Symp IEEE |
Volume |
|
Year |
1972 |
Abstract |
At the present stage of knowledge regarding successful treatment of breast malignancies, early detection is the most significant factor in the survival of the patient. The extent to which ultrasound visualization methods can act as an adjunct to present techniques is discussed in this paper. |
Title |
The potential of ultrasound visualization for detecting the presence of abnormal structures within the female breast. |
Author |
Kelly Fry E, Kossoff G, Hindman HA Jr. |
Journal |
Proc Ultrason Symp IEEE |
Volume |
|
Year |
1971 |
Abstract |
At the present stage of knowledge regarding sucessful treatment of breast malignancies, early detection is the most significant factor in the survival of the patient. The extent to which ultrasound visualization methods can act as an adjunct to present techniques is discussed in this paper. |
Title |
The present status of the safety of ultrasonic diagnosis in the area of obstetrics - the effect of ultrasound irradiation on pregnant mice as indicated in their fetuses. |
Author |
Tachihana M, Tachihana Y, Suzuki M. |
Journal |
Supersonic Med |
Volume |
|
Year |
1977 |
Abstract |
No abstract available. |
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