scholarly journals The Application of Adaptive Time Gain Compensation in an Improved Breast Ultrasound Tomography Algorithm

2019 ◽  
Vol 9 (12) ◽  
pp. 2574
Author(s):  
Chang Liu ◽  
Binzhen Zhang ◽  
Chenyang Xue ◽  
Guojun Zhang ◽  
Wendong Zhang ◽  
...  
Keyword(s):  
Attenuation Coefficient ◽  
Ultrasonic Transducer ◽  
Correlation Method ◽  
Reconstruction Algorithm ◽  
Ultrasound Tomography ◽  
Attenuation Coefficients ◽  
Gain Compensation ◽  
Adaptive Time ◽  
Pulse Echo ◽  
Horizontal Slice

In order to better detect information about a mass in breast tissue, an ultrasound tomography algorithm based on adaptive time gain compensation (TGC) was designed. Field II was utilized to automatically evaluate the phantom attenuation coefficient and compensate for the attenuated image. The image reconstruction algorithm process is presented here. Furthermore, the experimental setup with the cylindrical motion of a piezoelectric micromachined ultrasonic transducer (PMUT) linear array was used to detect the mass in the breast model. The attenuation coefficient was evaluated by using the spectral cross-correlation method. According to the acquired attenuation coefficients, TGC compensates for the pulse-echo signal, and the horizontal slice image was reconstructed using the tomography algorithm. The experimental results show that this algorithm can evaluate the attenuation coefficient of the breast model and improve the ability to detect an internal mass. At the same time, the realization of attenuation compensation with software is beneficial to the development of portable medical equipment.

Backscatter Coefficient Measurements Using a Reference Phantom to Extract Depth-Dependent Instrumentation Factors

1990 ◽  
Vol 12 (1) ◽  
pp. 58-70 ◽  
Author(s):  
Lin Xin Yao ◽  
James A. Zagzebski ◽  
Ernest L. Madsen
Keyword(s):  
Attenuation Coefficient ◽  
Time Domain ◽  
Reduction Method ◽  
Processing Technique ◽  
Processing Method ◽  
Backscatter Coefficient ◽  
Attenuation Coefficients ◽  
Reference Phantom ◽  
Dependent Signal ◽  
Data Reduction Method

In previous work, we demonstrated that accurate backscatter coefficient measurements are obtained with a data reduction method that explicitly accounts for experimental factors involved in recording echo data. An alternative, relative processing method for determining the backscatter coefficient and the attenuation coefficient is presented here. This method involves comparison of echo data from a sample with data recorded from a reference phantom whose backscatter and attenuation coefficients are known. A time domain processing technique is used to extract depth and frequency dependent signal ratios for the sample and the reference phantom. The attenuation coefficient and backscatter coefficient of the sample are found from these ratios. The method is tested using tissue-mimicking phantoms with known scattering and attenuation properties.

Theoretical Study of the Photon Interaction for Zirconium Alloy at 1 keV to 100 MeV

2016 ◽  
Vol 675-676 ◽  
pp. 730-733
Author(s):  
Chumphon Khobkham ◽  
W. Chaiphaksa ◽  
P. Limkitjaroenporn ◽  
P. Prongsamrong ◽  
P. Wiwatkanjana ◽  
...  
Keyword(s):  
Attenuation Coefficient ◽  
Total Mass ◽  
Zirconium Alloy ◽  
Gamma Ray ◽  
Mass Attenuation Coefficient ◽  
Chemical Compositions ◽  
Electron Densities ◽  
Attenuation Coefficients ◽  
Effective Atomic Numbers ◽  
Mass Attenuation

In this work, the total mass attenuation coefficient and partial interactions of the zirconium alloy have been calculated by WinXCom program at 1 keV-100 MeV gamma ray energies. Zr2(Fe,Ni) alloys was studied for the mass attenuation coefficients, photoelectric absorption, incoherent, coherent and pair production processes. The effective atomic numbers and electron densities were also calculated. The calculated results show that the total mass attenuation coefficient decreased with increasing of gamma rays energy. The value of total mass attenuation coefficient of each material was different, which depend on chemical compositions of alloy. The partials interactions, effective atomic numbers and electron densities were also calculated and discussed.

Gamma Ray Attenuation Coefficient Measurement in Energies 1172 keV and 1332 keV for Neutron Absorbent Saturated Solutions

2006 ◽  
Author(s):  
Majid Jalali
Keyword(s):  
Attenuation Coefficient ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Neutron Absorption ◽  
Attenuation Coefficients ◽  
Neutron Sources ◽  
Coefficient Measurement ◽  
Gamma Ray Attenuation ◽  
Mass Attenuation Coefficients ◽  
Saturated Solutions

The compounds, Na2B4O7, H3BO3, CdCl2 and NaCl and their solutions, attenuate gamma rays in addition to neutron absorption. These compounds are widely used in shielding of neutron sources, reactor control and neutron converters. Mass attenuation coefficients of gamma related to saturated solutions of the above four compounds, in energies 1172 keV and 1332 keV have been measured by NaI detector and agree very well with the results obtained by Xcom code. Experiment and computation show that, H3BO3 has the highest gamma ray attenuation coefficient among the aforementioned compounds.

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.

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