Time domain reconstruction of sound speed and attenuation in ultrasound computed tomography using full wave inversiona)

2017 ◽  
Vol 141 (3) ◽  
pp. 1595-1604 ◽  
Author(s):  
M. Pérez-Liva ◽  
J. L. Herraiz ◽  
J. M. Udías ◽  
E. Miller ◽  
B. T. Cox ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Time Domain ◽  
Sound Speed ◽  
Full Wave ◽  
Ultrasound Computed Tomography

scholarly journals Breast Acoustic Parameter Reconstruction Method Based on Capacitive Micromachined Ultrasonic Transducer Array

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 963
Author(s):  
Yu Pei ◽  
Guojun Zhang ◽  
Yu Zhang ◽  
Wendong Zhang
Keyword(s):  
Computed Tomography ◽  
Time Reversal ◽  
Sound Speed ◽  
Ultrasonic Transducer ◽  
Reconstruction Method ◽  
Propagation Theory ◽  
Speed Distribution ◽  
Ultrasound Computed Tomography ◽  
Wide Range ◽  
Capacitive Micromachined Ultrasonic Transducer

Ultrasound computed tomography (USCT) systems based on capacitive micromachined ultrasonic transducer (CMUT) arrays have a wide range of application prospects. For this paper, a high-precision image reconstruction method based on the propagation path of ultrasound in breast tissue are designed for the CMUT ring array; that is, time-reversal algorithms and FBP algorithms are respectively used to reconstruct sound speed distribution and acoustic attenuation distribution. The feasibility of this reconstruction method is verified by numerical simulation and breast model experiments. According to reconstruction results, sound speed distribution reconstruction deviation can be reduced by 53.15% through a time-reversal algorithm based on wave propagation theory. The attenuation coefficient distribution reconstruction deviation can be reduced by 61.53% through FBP based on ray propagation theory. The research results in this paper will provide key technological support for a new generation of ultrasound computed tomography systems.

A Prior-Information-Based Combination Solution for Picking the Difference of Time-of-Flight in Ultrasound Computed Tomography

2020 ◽  
Vol 10 (3) ◽  
pp. 763-768 ◽  
Author(s):  
Xiaoyue Fang ◽  
Junjie Song ◽  
Kuolin Liu ◽  
Yun Wu ◽  
Qiude Zhang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Sound Speed ◽  
Mean Squared Error ◽  
Median Filter ◽  
Time Of Flight ◽  
Disease Diagnosis ◽  
Phantom Experiment ◽  
Squared Error ◽  
Ultrasound Computed Tomography ◽  
The Difference

Sound speed imaging is one modal of ultrasound computed tomography (USCT) which is helpful for early breast disease diagnosis. One of the most critical processes of sound speed reconstruction is time-of-flight picking. As each of the traditional time-of-flight picking methods has shortcomings for real data, in this study, a practical priorinformation-based combination (PIBC) solution for picking the difference of time-of-flight between the reference data and the object data (DTOF) is proposed to enhance the reconstruction accuracy and uniformity. By using DTOF, some system bias will be effectively alleviated. Firstly, by analyzing the signal-amplitude, the "penetrating-through-the-object" and the "bypassing-the-object" signals are distinguished. Then for the "penetrating-throughthe-object" signals, based on the 'majority rule,' the consistency of DTOF picked by different methods are calculated as a basis to combine the advantages of different picking methods; for the "bypassing-the-object" signals, the DTOF closest to zero is chosen. Finally, the DTOFs are post-processed to suppress the noise by a median filter and to fix the deficiency of the system by an interpolation operator. The new solution is verified by in vitro breast phantom experiment conducted on the home-made USCT system "Lucid." The proposed PIBC solution can quantitatively decrease Root Mean Squared Error (RMSE) and Mean Squared Error (MSE) of DTOF picking and enhance the image quality of reconstructed sound speed images with higher accuracy and uniformity. This work is significant for ray-based sound speed reconstruction and can provide a fine initial solution for high-resolution wave-based reconstruction.

scholarly journals Combating acoustic heterogeneity in photoacoustic computed tomography: A review

2020 ◽  
Vol 13 (03) ◽  
pp. 2030007 ◽  
Author(s):  
Tong Wang ◽  
Wen Liu ◽  
Chao Tian
Keyword(s):  
Computed Tomography ◽  
Sound Speed ◽  
Imaging Modality ◽  
Biological Tissues ◽  
Research Progress ◽  
Joint Reconstruction ◽  
Ultrasound Computed Tomography ◽  
Acoustic Inversion ◽  
Heterogeneity Correction ◽  
Imaging Performance

Based on the energy conversion of light into sound, photoacoustic computed tomography (PACT) is an emerging biomedical imaging modality and has unique applications in a range of biomedical fields. In PACT, image formation relies on a process called acoustic inversion from received photoacoustic signals. While most PACT systems perform this inversion with a basic assumption that biological tissues are acoustically homogeneous, the community gradually realizes that the intrinsic acoustic heterogeneity of tissues could pose distortions and artifacts to finally formed images. This paper surveys the most recent research progress on acoustic heterogeneity correction in PACT. Four major strategies are reviewed in detail, including half-time or partial-time reconstruction, autofocus reconstruction by optimizing sound speed maps, joint reconstruction of optical absorption and sound speed maps, and ultrasound computed tomography (USCT) enhanced reconstruction. The correction of acoustic heterogeneity helps improve the imaging performance of PACT.

Handwriting With Sound-Speed Imaging Using Ultrasound Computed Tomography

2021 ◽  
Vol 5 (10) ◽  
pp. 1-3
Author(s):  
Panagiotis Koulountzios ◽  
Tomasz Rymarczyk ◽  
Manuchehr Soleimani
Keyword(s):  
Computed Tomography ◽  
Sound Speed ◽  
Ultrasound Computed Tomography
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