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BRL Abstracts Database |
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Your search for ultrasound produced 3296 results. Page 220 out of 330
| Title |
Response to "Comment on ultrasound-induced lung hemorrhage is not caused by inertial cavitation." |
| Author |
Frizzell LA, Kramer JM, Zachary JF, O'Brien WD Jr. |
| Journal |
J Acoust Soc Am |
| Volume |
|
| Year |
2001 |
| Abstract |
No abstract available. |
| Title |
Response to sublethal heat treatment of prostatic tumor cells and of prostatic tumor infiltrating T-cells. |
| Author |
Kramer G, Steiner GE, Gröbl M, Hrachowitz K, Reithmayr F, Paucz L, Newman M, Madersbacher S, Gruber D, Susani M, Marberger M. |
| Journal |
Prostate |
| Volume |
|
| Year |
2004 |
| Abstract |
BACKGROUND: To investigate the possibilities offered by high intensity focused ultrasound (HIFU) in the field of tumor vaccination, we analyzed how prostatic cancer (CaP) cells react towards heat treatment and whether increased access to CaP cells by the immune system would be the result. METHODS: Heat/stress response of CaP cells in situ and of CaP cell lines was analyzed by immunohistochemistry, Western blotting, and Atlas array. A heat-induced change in immune recognition was analyzed functionally using human T-helper (Th)1 and Th2-cytokine release with tumor infiltrating T-lymphocytes (TIL) as responder and autologous CaP cells either heated or untreated as stimulator cells. RESULTS: Transcription of 68 out of 500 genes was upregulated by sublethal heat in LNCaP and PC3 cells. Significantly upregulated stress protein (SP) expression (HSP-72, -73, GRP-75, -78) was seen at the border zone of HIFU treatment. Remarkably, even untreated benign prostatic hyperplasia (BPH) specimens revealed relative overexpression of heat shock protein (HSP)-72, -73 and glucose regulated protein (GRP)-75, -78. Heated CaP cells increased Th1-cytokine (IL-2, IFN-gamma, TNF-alpha) release but decreased Th2-cytokine (IL-4, -5, -10) release of TIL. CONCLUSIONS: HIFU treatment may alter the presentation of prostate tissue and tumor antigens and this presentation is most likely stimulatory. HSP-72/73 overexpression in untreated BPH may suggest a mechanism by which BPH can incite inflammation. Copyright 2003 Wiley-Liss, Inc. |
| Title |
Restoration of medical ultrasound images using two-dimensional homomorphic deconvolution. |
| Author |
Taxt T. |
| Journal |
IEEE Trans UFFC |
| Volume |
|
| Year |
1995 |
| Abstract |
Describes how two-dimensional (2D) homomorphic deconvolution can be used to improve the lateral and radial resolution of medical ultrasound images recorded by a sector scanner. The recorded radio frequency ultrasound image in polar coordinates is considered as a 2D sequence of angle and depth convolved with a 2D space invariant point-spread function (PSF). Each polar coordinate sequence is transformed into the 2D complex cepstrum domain using the fast Fourier transform for Cartesian coordinates. The low-angle and low-depth portion of this sequence is taken as an estimate of the complex cepstrum representation of the PSF. It is transformed back to the Fourier frequency domain and is used to compute the deconvolved angle and depth sequence by 2D Wiener filtering. Two-dimensional homomorphic deconvolution produced substantial improvement in the resolution of B-mode images of a tissue-mimicking phantom in vitro and of several human tissues in vivo. It was better than lateral or radial homomorphic deconvolution alone, and better than 2D Wiener filtering with a PSF recorded in vitro |
| Title |
Results of breast echographic examinations in Sydney, Australia. 1972-1979. |
| Author |
Jellins J, Reeve TS, Croll J, Kossoff G. |
| Journal |
Semin Ultrasound |
| Volume |
|
| Year |
1982 |
| Abstract |
No abstract available. |
| Title |
Reversible block of nerve conduction by ultrasound. |
| Author |
Young RR, Henneman E. |
| Journal |
Arch Neurol |
| Volume |
|
| Year |
1961 |
| Abstract |
No abstract available. |
| Title |
Reversible effects of ultrasound on spinal reflexes. |
| Author |
Shealy CN, Henneman E. |
| Journal |
Arch Neurol |
| Volume |
|
| Year |
1962 |
| Abstract |
No abstract available. |
| Title |
Review of quantitative ultrasound: Envelope statistics and backscatter coefficient imaging and contributions to diagnostic ultrasound |
| Author |
Oelze ML, Mamou J |
| Journal |
IEEE TUFFC |
| Volume |
|
| Year |
2016 |
| Abstract |
Conventional medical imaging technologies, including ultrasound, have continued to improve over the years. For example, in oncology, medical imaging is characterized by high sensitivity, i.e., the ability to detect anomalous tissue
features, but the ability to classify these tissue features from images often lacks specificity. As a result, a large number of biopsies of tissues with suspicious image findings are performed each year with a vast majority of these biopsies resulting in a negative finding. To improve specificity of cancer imaging, quantitative imaging techniques can play an important role. Conventional ultrasound B-mode imaging is mainly qualitative in nature. However, quantitative ultrasound (QUS) imaging can provide specific numbers related to tissue features that can increase the specificity of image findings leading to improvements in diagnostic ultrasound. QUS imaging can encompass a wide variety of techniques including spectral-based parameterization, elastography, shear wave imaging, flow estimation, and envelope statistics. Currently, spectral-based parameterization and envelope statistics are not available on most conventional clinical ultrasound machines. However, in recent years, QUS techniques involving spectral-based parameterization and envelope statistics have demonstrated success in many applications, providing additional diagnostic capabilities. Spectral-based techniques include the estimation of the backscatter coefficient (BSC), estimation of attenuation, and estimation of scatterer properties such as the correlation length associated with an effective scatterer diameter (ESD) and the effective acoustic concentration (EAC) of scatterers. Envelope statistics include the estimation of the number density of scatterers and quantification of coherent to incoherent signals produced from the tissue. Challenges for clinical application include correctly accounting for attenuation effects and transmission losses and implementation of QUS on clinical devices. Successful clinical and preclinical applications demonstrating the ability of QUS to improve medical diagnostics include characterization of the myocardium during the cardiac cycle, cancer detection, classification of solid tumors and lymph nodes, detection and quantification of fatty liver disease, and monitoring and assessment of therapy. |
| Title |
Review: Absorption and dispersion of ultrasound in biological tissue. |
| Author |
Wells PNT. |
| Journal |
Ultrasound Med Biol |
| Volume |
|
| Year |
1975 |
| Abstract |
Absorption of ultrasound is the process of conversion of vibrational energy into heat. In biological soft tissues, the absorption coefficients are roughly proportional to the frequency; typically alpha =1 dB cm(^-1) MHz(^-1). The velocities in soft tissues are similar, being about 1500 msec(^-1). Classical viscosity theory cannot explain this form of absorption. A relaxation process is associated with a range of frequency over which there is dispersion in velocity-from a low value at low frequencies to a high value at high frequencies-and a maximum in the absorption per wavelength. Experimental data, particularly for haemoglobin solutions, indicate that absorption and dispersion in biological materials are due to relaxation processes distributed over a range of frequencies. The dispersion is small, and usually negligible in relation to variations and uncertainties of measurement. The natures of relaxation processes which are involved have yet to be resolved; possibilities include solvent-solute interactions and disturbances in H-bonding equilibria. Lung has a lower velocity than that of solid tissues, whereas that of bone is higher both have a higher value of absorption. |
| Title |
ROC analysis of ultrasound tissue characterization classifiers for breast cancer diagnosis. |
| Author |
Gefen S, Tretiak OJ, Piccoli CW, Donohue KD, Petropulu AP, Shankar PM, Dumane VA, Huang L, Kutay MA, Genis V, Forsberg F, Reid JM, Goldberg BB. |
| Journal |
IEEE Trans Med Imaging |
| Volume |
|
| Year |
2003 |
| Abstract |
Breast cancer diagnosis through ultrasound tissue characterization was studied using receiver operating characteristic (ROC) analysis of combinations of acoustic features, patient age, and radiological findings. A feature fusion method was devised that operates even if only partial diagnostic data are available. The ROC methodology uses ordinal dominance theory and bootstrap resampling to evaluate A/sub z/ and confidence intervals in simple as well as paired data analyses. The combined diagnostic feature had an A/sub z/ of 0.96 with a confidence interval of [0.93, 0.99] at a significance level of 0.05. The combined features show statistically significant improvement over prebiopsy radiological findings. These results indicate that ultrasound tissue characterization, in combination with patient record and clinical findings, may greatly reduce the need to perform biopsies of benign breast lesions. |
| Title |
Rochester center for biomedical ultrasound 1992 annual report. |
| Author |
Unknown. |
| Journal |
Rep Rochester Cent |
| Volume |
|
| Year |
1992 |
| Abstract |
No abstract available. |
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