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BRL Abstracts Database |
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Your search for ultrasound produced 3296 results. Page 67 out of 330
| Title |
Clinical results with scanned, intensity-modulated, focused ultrasound (SIMFU) system. |
| Author |
Lele PP, Goddard J, Blanter M. |
| Journal |
Proc Seventy-third Sci Assemb Annu Meet Radiol Soc N Am |
| Volume |
|
| Year |
1987 |
| Abstract |
No abstract available. |
| Title |
Clinical spectra-color ultrasonography. |
| Author |
Purnell EW, Sokollu A, Holasek E, Cappaert WE. |
| Journal |
J Clin Ultrasound |
| Volume |
|
| Year |
1975 |
| Abstract |
Results of preliminary clinical trials of spectra-color ultrasonography are presented. The instrumentation is calibrated so that normal ocular tissues produce a near-white display. Scans of eyes with various diseases differ from the scans of normal eyes, indicating a variation in frequency responses. |
| Title |
Clinical ultrasound in neoplastic disease: Echography for tumor diagnosis. |
| Author |
Kobayashi T. |
| Journal |
J Univ Occup Environ Health Jpn |
| Volume |
|
| Year |
1979 |
| Abstract |
Ultrasonic echography has been recently highlighted for the clinical diagnosis of malignant neoplasm and other benign tumors beacause it is a noninvasive method and has no physical hazard as is the case with the radiological technique. It is a useful technique because it will offer considerable diagnostic information on the visualization of soft tissue pathology. Such information was rather difficult to obtain by the radiological method, and especially difficult was the visualization of malignant or benign tumors of soft tissue origin. Currently used techniques for ultrasonic echography are classified as compound contact scanning, arc-scanning through water-immersion, radial scanning (PPI), and recently developed high-speed real time electronic linear or sector scanning. These techniques can be applied to the clinincal diagnosis of brain tumors, tumors of the orbit techniques can be applied to the clinical diagnosis of brain tumors, tumors of the orbit and eye, ENT tumors, thyroid tumors, abdominal tumors including pelvic tumors, breast tumors, urogenital tumors or soft tissue tumors of the extremities. Clinical usefulness of echography by the sensitivity graded method for breast cancer and gray scale image was highly appraised because of its diagnostic accuracy rates: T1 81%, T2 93%, and T3 100% according to the tumor size of TNM classification, and 97% for scirrhous carcinoma, 87% for medullary carcinoma, and 78% for papillary carcinoma. These rates may be considered to be better than those achieved by mammography. For echographic diagnosis of abdominal tumors, the technique can be used for neoplastic lesions in soft tissue organs such as the liver, gallbladder, pancreas, spleen, kidney, uterus, ovary and retroperitoneal space. It is especially useful in determining whether such lesions are cystic or a solid mass, for visualization of the tumor mass in anatomical relation to various intraabdominal organs, the preoperative determination of the tumor size, and it may also offer some important diagnostic imformation on whether the mass is malignant or benign in some instances. Those diagnostic information can be also obtained for the soft tissue tumors in the extremities. The technique may be a useful clincal auxiliary aid for differential diagnosis of neoplastic lesions, especially cancer detection in various organs. Therefore, this review focused on the viewpoint of cancer and medical ultrasonics, especially the current status of clinical echography in demonstrating the typical echograms of various neoplasms. |
| Title |
Clinical use of ultrasound biomicroscopy. |
| Author |
Pavlin CJ, Harasiewicz K, Sherar MD, Foster FS. |
| Journal |
Ophthalmology |
| Volume |
|
| Year |
1991 |
| Abstract |
The authors have developed a method of obtaining images of cross-sections of the intact anterior globe at microscopic resolution. High-frequency ultrasound transducers (50-100 MHz) have been developed and incorporated into a clinical B-scan device capable of producing images in the living human eye to a depth of approximately 4 mm at an axial and lateral resolution approaching 20 microns. Clinical use of this instrument is no more difficult than conventional immersion ultrasonography. The authors' results in a series of 14 clinical cases have shown that this method can provide information unavailable from any other imaging technique. Anterior segment tumors difficult to define with conventional ultrasound can be measured and the extent of invasion determined. Differentiation of tissue on the basis of internal acoustic characteristics is aided by the very fine backscatter speckle patterns at these frequencies. Pathology behind anterior segment opacities can be imaged in detail and the ability to image angle structures in cross-section allows a new quantitative method of gonioscopy. The ability to define the relationship of the iris, posterior chamber, zonules, ciliary body, and lens is potentially helpful in understanding mechanisms of glaucoma. Ocular structures can be measured with increased accuracy. Clinical ultrasound biomicroscopy (UBM) has shown significant potential as an aid in diagnoses of ocular disease. |
| Title |
Clinical utility of contrast-enhanced ultrasound in neurosonology. |
| Author |
Droste DW. |
| Journal |
Eur Neurol |
| Volume |
|
| Year |
2008 |
| Abstract |
Extracranial and transcranial colour-coded duplex sonography (TCCD) are used routinely in clinical practice to assess physiologic and pathologic arterial blood flow to the brain. Such investigations are straightforward, safe, and cost effective, and can be repeated frequently for patient follow-up. In addition, the portability of extracranial colour-coded duplex sonography and TCCD provides the option of bedside investigations, particularly useful for evaluation of the critically ill patient. However, duplex ultrasound can be hampered by insufficient acoustic penetration, an unfavourable insonation angle, or by conditions of low or no flow. Echocontrast agents capable of surviving pulmonary and capillary transit have been developed, and such agents increase the Doppler signal and, therefore, the success rate of neurosonographic investigations. Approximately 20% of TCCD studies involve poor insonation conditions and, therefore, the use of echocontrast agents is of particular interest for this application. Levovist and SonoVue are the two agents currently approved for use in neurosonography. Such agents have a relatively long-lasting effect (up to 7 min), and can be administered as a single injection or, alternatively, a fractionated injection protocol can be used, depending on the quality of the window. |
| Title |
Coded excitation for ultrasound tissue harmonic imaging. |
| Author |
Song J, Kim S, Sohn HY, Song TK, Yoo YM. |
| Journal |
Ultrasonics |
| Volume |
|
| Year |
2010 |
| Abstract |
Coded excitation can improve the signal-to-noise ratio (SNR) in ultrasound tissue harmonic imaging (THI). However, it could suffer from the increased sidelobe artifact caused by incomplete pulse compression due to the spectral overlap between the fundamental and harmonic components of ultrasound signal after nonlinear propagation in tissues. In this paper, three coded tissue harmonic imaging (CTHI) techniques based on bandpass filtering, power modulation and pulse inversion (i.e., CTHI-BF, CTHI-PM, and CTHI-PI) were evaluated by measuring the peak range sidelobe level (PRSL) with varying frequency bandwidths. From simulation and in vitro studies, the CTHI-PI outperforms the CTHI-BF and CTHI-PM methods in terms of the PRSL, e.g., -43.5dB vs. -24.8dB and -23.0dB, respectively. |
| Title |
Coded excitation using biphase-coded pulse with mismatched filters for high-frequency ultrasound imaging. |
| Author |
Hu C-H, Liu R, Zhou Q, Yen J, Shung KK. |
| Journal |
Ultrasonics |
| Volume |
|
| Year |
2006 |
| Abstract |
A scheme of using phase-coded excitation and mismatched filter compression for high-frequency ultrasound imaging is presented in this paper. Biphase-coded pulses were constructed to excite the transducer. Received signals were compressed with mismatched filters optimized by minimizing peak-sidelobe-level (PSL). Both simulation and experiments were carried out to demonstrate the advantage of this technique. The simulation results demonstrated a possible sidelobe reduction (<−90 dB) with a slightly decrease of the signal-to-noise ratio of less than 1 dB compared with the compression using matched filters alone. The experimental results showed about 14 dB SNR improvement as well as −40 dB sidelobe level when the Barker-13 code excitation with 3-cycle sinusoidal wave carrier was used. |
| Title |
Coherent high-resolution ultrasound reflection mode CT imaging. |
| Author |
Ylitalo J, Greenleaf JF, Bahn RC. |
| Journal |
Proc Ultrason Symp IEEE |
| Volume |
|
| Year |
1986 |
| Abstract |
A coherent ultrasound reflection mode CT imaging method has been developed to image small, 10 mm x 10 mm, areas in objects such as liver. Since we use only a single radial scan and straight-line CT reconstruction, the processing time and computer as well as hardware requirements are reduced considerably compared to those of ordinary transmission or reflection CT. The main limitation of the method is the need for correction for speed variations in intervening medium. This is done by tracing "brightest" sinusoids in the Radon space of the data to obtain estimates of the time shifts. Images of simulated objects, real phantoms, and liver specimens are presented and compared to images obtained by compound B-scans from the same objects. These images show that the resolution of the imaging method is about 0.3 mm using a commercial 3.5 MHz medium focused transducer. |
| Title |
Coherent high-resolution ultrasound reflection mode CT imaging. |
| Author |
Ylitalo J, greenleaf JF, Bahn RC. |
| Journal |
Proc IEEE Ultrasonic Symposium |
| Volume |
|
| Year |
1986 |
| Abstract |
A coherent high-resolution ultrasound reflection mode CT imaging method has been developed for imaging small restricted areas Inside objects such as liver. The high spatial resolution of the method results from a large, fully enclosing imaging aperture and coherent signal processing. Since only a single radial scan and common straight-line CT reconstruction are required, the processing time and computer as well as hardware requirements are reduced considerably compared to those of ordinary transmission or reflection CT. The main limitation of the method is the need for correction for speed variations in an intervening medium. This is done by tracing "brightest" sinusoids in the Radon space of the data to obtain estimates of the time shifts.
Images of simulated objects, real phantoms, and liver specimens are presented and, in experiments with tissues, compared to images obtained by compound B-scans from exactly the same cross-sectional planes of the object. Experiments show that the new imaging method is operational and that the spatial resolution of about 0.3 mm can be achieved using a commercial 3.5 MHz transducer. |
| Title |
Coherent speckle in ultrasound images. |
| Author |
Magnin PA. |
| Journal |
Hewlett-Packard Journal |
| Volume |
|
| Year |
1983 |
| Abstract |
No abstract available. |
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