High-frequency estimation of the ultrasonic attenuation coefficient slope obtained in human skin: simulation and in vivo results

1999 ◽  
Vol 25 (3) ◽  
pp. 421-429 ◽  
Author(s):  
Christelle Guittet ◽  
Frédéric Ossant ◽  
Jean-Pierre Remenieras ◽  
Léandre Pourcelot ◽  
Marceau Berson
Keyword(s):  
Human Skin ◽  
Attenuation Coefficient ◽  
High Frequency ◽  
Ultrasonic Attenuation ◽  
Frequency Estimation

Evaluation of Thermal Degradation of 2.25Cr-1Mo Steel by High Frequency Ultrasonic Attenuation Measurement

2005 ◽  
Vol 475-479 ◽  
pp. 257-260 ◽  
Author(s):  
Jai Won Byeon ◽  
C.S. Kim ◽  
S.I. Kwun ◽  
S.J. Hong
Keyword(s):  
Attenuation Coefficient ◽  
High Frequency ◽  
Ultrasonic Attenuation ◽  
Attenuation Coefficients ◽  
Low Frequencies ◽  
High Frequencies ◽  
Noticeable Increase ◽  
Mean Size ◽  
Longitudinal Ultrasonic Wave ◽  
Degradation Time

It was attempted to assess nondestructively the degree of isothermal degradation of 2.25Cr-1Mo steel by using high frequency longitudinal ultrasonic wave. Microstructural parameter (mean size of carbides), mechanical property (Vickers hardness) and ultrasonic attenuation coefficient were measured for the 2.25Cr-1Mo steel isothermally degraded at 630°C for up to 4800 hours in order to find the correlation among these parameters. The ultrasonic attenuation coefficients at high frequencies (over 35MHz) were observed to increase rapidly in the initial 1000 hours of degradation time and then slowly thereafter, while the ones at low frequencies showed no noticeable increase. Ultrasonic attenuation at high frequencies increased as a function of mean size of carbides. Ultrasonic attenuation coefficient was found to have a linear correlation with the hardness, and suggested accordingly as a potential nondestructive evaluation parameter for assessing the mechanical strength reduction of the isothermally degraded 2.25Cr-1Mo steel.

In vivo ultrasonic tissue characterization of human skin: Estimation of the slope of the attenuation coefficient

1998 ◽  
Vol 7 ◽  
pp. S46
Author(s):  
C. Guittet ◽  
F. Ossant ◽  
J.P. Remenieras ◽  
M. Berson ◽  
L. Pourcelot
Keyword(s):  
Human Skin ◽  
Attenuation Coefficient ◽  
Tissue Characterization

scholarly journals Synthetic Aperture Technique Applied to Tissue Attenuation Imaging

2011 ◽  
Vol 36 (4) ◽  
pp. 927-935 ◽  
Author(s):  
Ziemowit Klimonda ◽  
Jerzy Litniewski ◽  
Andrzej Nowicki
Keyword(s):  
Attenuation Coefficient ◽  
Frequency Estimation ◽  
Ultrasonic Pulse ◽  
Synthetic Aperture ◽  
Propagation Path ◽  
Single Spectrum ◽  
Mean Frequency ◽  
Ultrasonic Scanner

AbstractThe attenuating properties of biological tissue are of great importance in ultrasonic medical imaging. Investigations performedin vitroandin vivoshowed the correlation between pathological changes in the tissue and variation of the attenuation coefficient. In order to estimate the attenuation we have used the downshift of mean frequency (fm) of the interrogating ultrasonic pulse propagating in the medium. To determine thefmalong the propagation path we have applied thefmestimator (I/Q algorithm adopted from the Doppler mean frequency estimation technique). The mean-frequency shift trend was calculated using Single Spectrum Analysis. Next, the trends were converted into attenuation coefficient distributions and finally the parametric images were computed. The RF data were collected in simulations and experiments applying the synthetic aperture (SA) transmit-receiving scheme. In measurements the ultrasonic scanner enabling a full control of the transmission and reception was used. The resolution and accuracy of the method was verified using tissue mimicking phantom with uniform echogenicity but varying attenuation coefficient.

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