The Experts below are selected from a list of 138 Experts worldwide ranked by ideXlab platform
Kathryn R Nightingale - One of the best experts on this subject based on the ideXlab platform.
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acoustic radiation force impulse imaging of the mechanical properties of arteries in vivo and ex vivo results
Ultrasound in Medicine and Biology, 2004Co-Authors: Gregg E Trahey, Mark L Palmeri, Rex C Bentley, Kathryn R NightingaleAbstract:We present results of a pilot study of ex vivo and in vivo acoustic radiation force impulse (ARFI) imaging demonstrating measurements of the mechanical properties of the carotid and popliteal arteries. The results were obtained on a modified Commercial Scanner, providing coregistered B-mode and color Doppler images. 2D and 1D through time images are formed from the measurements of tissues' response to very brief and localized applications of radiation force. The images show good correlation with B-mode and, in ex vivo studies, pathology-based characterizations of vessel geometry and plaque stiffness. In vivo measurements of arterial response during both systole and diastole are presented. We address implementation issues and discuss potential applications of this new vascular imaging method.
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acoustic radiation force impulse imaging of the mechanical properties of arteries in vivo and ex vivo results
Ultrasound in Medicine and Biology, 2004Co-Authors: Gregg E Trahey, Mark L Palmeri, Rex C Bentley, Kathryn R NightingaleAbstract:Abstract We present results of a pilot study of ex vivo and in vivo acoustic radiation force impulse (ARFI) imaging demonstrating measurements of the mechanical properties of the carotid and popliteal arteries. The results were obtained on a modified Commercial Scanner, providing coregistered B-mode and color Doppler images. 2D and 1D through time images are formed from the measurements of tissues’ response to very brief and localized applications of radiation force. The images show good correlation with B-mode and, in ex vivo studies, pathology-based characterizations of vessel geometry and plaque stiffness. In vivo measurements of arterial response during both systole and diastole are presented. We address implementation issues and discuss potential applications of this new vascular imaging method. (E-mail: gregg.trahey@duke.edu
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the use of acoustic streaming in breast lesion diagnosis a clinical study
Ultrasound in Medicine and Biology, 1999Co-Authors: Kathryn R Nightingale, Phyllis J Kornguth, Gregg E TraheyAbstract:Results from a clinical study are presented, in which ultrasonically-induced acoustic streaming was successfully used to differentiate fluid-filled lesions (cysts) from solid lesions in the breast. In this study, high-intensity ultrasound pulses from a modified Commercial Scanner were used to induce acoustic streaming in cyst fluid, and this motion was detected using Doppler methods. Acoustic streaming was generated and detected in 14 of 15 simple cysts, and 4 of 14 sonographically indeterminate breast lesions. This lesion differentiation method appears to be particularly suited for diagnosis of small, possibly newer, cysts that appear indeterminate on conventional sonography due to their size. The results indicate that this method would be a useful adjunct to conventional sonography for the purpose of breast lesion classification.
Gregg E Trahey - One of the best experts on this subject based on the ideXlab platform.
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acoustic radiation force impulse imaging of the mechanical properties of arteries in vivo and ex vivo results
Ultrasound in Medicine and Biology, 2004Co-Authors: Gregg E Trahey, Mark L Palmeri, Rex C Bentley, Kathryn R NightingaleAbstract:We present results of a pilot study of ex vivo and in vivo acoustic radiation force impulse (ARFI) imaging demonstrating measurements of the mechanical properties of the carotid and popliteal arteries. The results were obtained on a modified Commercial Scanner, providing coregistered B-mode and color Doppler images. 2D and 1D through time images are formed from the measurements of tissues' response to very brief and localized applications of radiation force. The images show good correlation with B-mode and, in ex vivo studies, pathology-based characterizations of vessel geometry and plaque stiffness. In vivo measurements of arterial response during both systole and diastole are presented. We address implementation issues and discuss potential applications of this new vascular imaging method.
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acoustic radiation force impulse imaging of the mechanical properties of arteries in vivo and ex vivo results
Ultrasound in Medicine and Biology, 2004Co-Authors: Gregg E Trahey, Mark L Palmeri, Rex C Bentley, Kathryn R NightingaleAbstract:Abstract We present results of a pilot study of ex vivo and in vivo acoustic radiation force impulse (ARFI) imaging demonstrating measurements of the mechanical properties of the carotid and popliteal arteries. The results were obtained on a modified Commercial Scanner, providing coregistered B-mode and color Doppler images. 2D and 1D through time images are formed from the measurements of tissues’ response to very brief and localized applications of radiation force. The images show good correlation with B-mode and, in ex vivo studies, pathology-based characterizations of vessel geometry and plaque stiffness. In vivo measurements of arterial response during both systole and diastole are presented. We address implementation issues and discuss potential applications of this new vascular imaging method. (E-mail: gregg.trahey@duke.edu
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the use of acoustic streaming in breast lesion diagnosis a clinical study
Ultrasound in Medicine and Biology, 1999Co-Authors: Kathryn R Nightingale, Phyllis J Kornguth, Gregg E TraheyAbstract:Results from a clinical study are presented, in which ultrasonically-induced acoustic streaming was successfully used to differentiate fluid-filled lesions (cysts) from solid lesions in the breast. In this study, high-intensity ultrasound pulses from a modified Commercial Scanner were used to induce acoustic streaming in cyst fluid, and this motion was detected using Doppler methods. Acoustic streaming was generated and detected in 14 of 15 simple cysts, and 4 of 14 sonographically indeterminate breast lesions. This lesion differentiation method appears to be particularly suited for diagnosis of small, possibly newer, cysts that appear indeterminate on conventional sonography due to their size. The results indicate that this method would be a useful adjunct to conventional sonography for the purpose of breast lesion classification.
Mark L Palmeri - One of the best experts on this subject based on the ideXlab platform.
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4k 5 shear wave velocity estimation using acoustic radiation force impulsive excitation in liver in vivo
Internaltional Ultrasonics Symposium, 2006Co-Authors: Kathy Nightingale, Liang Zhai, Jeremy J Dahl, K Frinkley, Mark L PalmeriAbstract:Acoustic radiation force can be used to mechanically excite tissue in remote, focused locations, and the tissue response can be monitored using ultrasonic correlation based methods. The speed with which the resulting shear waves propagate away from the focal region can be estimated and used to quantify the material shear modulus, as originally proposed by Sarvazyan et. al. (1998). This imaging approach has been implemented by Bercoff et. al. (2004), using a highly parallel custom ultrasound system, and Helmholtz reconstructions. We have developed a system that is implemented on a Commercial Scanner using 4:1 parallel processing, and a new algorithm for estimating shear wave speed, which does not require 2nd order temporal and spatial differentiation of displacement data. The method is robust and generates consistent measurements over multiple acquisitions. The goal of our work is to develop this system for the purpose of staging liver fibrosis. The method was used to measure elastic moduli of liver in vivo in healthy human volunteers, and in a rat model, and the moduli obtained with this method are consistent with those reported in the literature
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acoustic radiation force impulse imaging of the mechanical properties of arteries in vivo and ex vivo results
Ultrasound in Medicine and Biology, 2004Co-Authors: Gregg E Trahey, Mark L Palmeri, Rex C Bentley, Kathryn R NightingaleAbstract:Abstract We present results of a pilot study of ex vivo and in vivo acoustic radiation force impulse (ARFI) imaging demonstrating measurements of the mechanical properties of the carotid and popliteal arteries. The results were obtained on a modified Commercial Scanner, providing coregistered B-mode and color Doppler images. 2D and 1D through time images are formed from the measurements of tissues’ response to very brief and localized applications of radiation force. The images show good correlation with B-mode and, in ex vivo studies, pathology-based characterizations of vessel geometry and plaque stiffness. In vivo measurements of arterial response during both systole and diastole are presented. We address implementation issues and discuss potential applications of this new vascular imaging method. (E-mail: gregg.trahey@duke.edu
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acoustic radiation force impulse imaging of the mechanical properties of arteries in vivo and ex vivo results
Ultrasound in Medicine and Biology, 2004Co-Authors: Gregg E Trahey, Mark L Palmeri, Rex C Bentley, Kathryn R NightingaleAbstract:We present results of a pilot study of ex vivo and in vivo acoustic radiation force impulse (ARFI) imaging demonstrating measurements of the mechanical properties of the carotid and popliteal arteries. The results were obtained on a modified Commercial Scanner, providing coregistered B-mode and color Doppler images. 2D and 1D through time images are formed from the measurements of tissues' response to very brief and localized applications of radiation force. The images show good correlation with B-mode and, in ex vivo studies, pathology-based characterizations of vessel geometry and plaque stiffness. In vivo measurements of arterial response during both systole and diastole are presented. We address implementation issues and discuss potential applications of this new vascular imaging method.
Rex C Bentley - One of the best experts on this subject based on the ideXlab platform.
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acoustic radiation force impulse imaging of the mechanical properties of arteries in vivo and ex vivo results
Ultrasound in Medicine and Biology, 2004Co-Authors: Gregg E Trahey, Mark L Palmeri, Rex C Bentley, Kathryn R NightingaleAbstract:Abstract We present results of a pilot study of ex vivo and in vivo acoustic radiation force impulse (ARFI) imaging demonstrating measurements of the mechanical properties of the carotid and popliteal arteries. The results were obtained on a modified Commercial Scanner, providing coregistered B-mode and color Doppler images. 2D and 1D through time images are formed from the measurements of tissues’ response to very brief and localized applications of radiation force. The images show good correlation with B-mode and, in ex vivo studies, pathology-based characterizations of vessel geometry and plaque stiffness. In vivo measurements of arterial response during both systole and diastole are presented. We address implementation issues and discuss potential applications of this new vascular imaging method. (E-mail: gregg.trahey@duke.edu
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acoustic radiation force impulse imaging of the mechanical properties of arteries in vivo and ex vivo results
Ultrasound in Medicine and Biology, 2004Co-Authors: Gregg E Trahey, Mark L Palmeri, Rex C Bentley, Kathryn R NightingaleAbstract:We present results of a pilot study of ex vivo and in vivo acoustic radiation force impulse (ARFI) imaging demonstrating measurements of the mechanical properties of the carotid and popliteal arteries. The results were obtained on a modified Commercial Scanner, providing coregistered B-mode and color Doppler images. 2D and 1D through time images are formed from the measurements of tissues' response to very brief and localized applications of radiation force. The images show good correlation with B-mode and, in ex vivo studies, pathology-based characterizations of vessel geometry and plaque stiffness. In vivo measurements of arterial response during both systole and diastole are presented. We address implementation issues and discuss potential applications of this new vascular imaging method.
T.g. Strand - One of the best experts on this subject based on the ideXlab platform.
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the molecular structure conformation force field and potential function to internal rotation of 2 2 dichloroacetamide as studied by quantum chemical calculations and gas electron diffraction data from photographic plates using a Commercial Scanner
Journal of Molecular Structure, 2004Co-Authors: Snefrid Gundersen, Svein Samdal, Ragnhild Seip, T.g. StrandAbstract:Abstract A description of how we presently use a Commercial Scanner to obtain electron diffraction data from photographic plates is given. Compared to data previously obtained from a microdensitometer the R -factors and the derived standard deviations for the structure parameters were reduced with approximately 50%. Quantum chemical calculations have been made using HF, DFT and MP2 and the basis sets 6-311++G** and Aug-cc-pVTZ. The calculations are not entirely consistent in their predictions. A syn -like conformation is determined experimentally. The dihedral angle H–C–CO is about 18 degrees, i.e. the C–H bond is pointing towards the CO bond. The most important structure parameters referred to a planar structure with C s symmetry are: R (CO)=1.223(4), R (C–N)=1.358(5), R (C–C)=1.538(6), R (C–Cl)=1.776(5), ∠OCN=125.1(5), ∠CCCl=110.8(3), ∠CCN=116.3(5) where distances are in A and angles in degrees. Estimated error limits are three standard deviations from the least-squares refinement. The experimental results are essentially in agreement with the quantum chemical calculations.
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A Commercial Scanner Applied as a Microdensitometer for Gas Electron-Diffraction Photographic Plates
Journal of Applied Crystallography, 1996Co-Authors: S. Gundersen, T.g. StrandAbstract:The present state of the hardware and software of our Joyce-Loebl MK III CS 1970 microdensitometer is reported. The modifications to the existing software necessary for it to be applicable to the data from an Agfa Arcus II Commercial Scanner are described. The accuracies of the two instruments are compared by the measurement and analysis of photographic plates for two data sets of the short nozzle-to-plate distance of benzene. For about 30000 measured points on both devices, the two instruments give practically the same accuracy, except for very light plates where the Joyce-Loebl results seem to be the best ones. The ra(C–C) distance obtained from the Scanner data is systematically elongated by about 0.5%. Acceptable agreement of the root-mean-square vibrational amplitudes from the two instruments is obtained. A sixfold increase in the number of points applied from the Scanner does not improve the agreement very much. The conclusion is that the Scanner, in connection with the applied software, can be used as a microdensitometer for gas electron-diffraction plates.