scholarly journals Detection of velocity and attenuation inclusions in the medical ultrasound tomography

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Victoria Filatova ◽  
Leonid Pestov ◽  
Alina Poddubskaya
Keyword(s):  
Acoustic Waves ◽  
Medical Ultrasound ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Amplitude Analysis ◽  
Ultrasound Tomography ◽  
Time Migration ◽  
Medical Diagnostic ◽  
Boundary Measurements ◽  
Energy Version

Abstract The paper is devoted to numerical research of the medical ultrasound tomography problem. This problem consists in finding small inclusions in the breast tissue by boundary measurements of the acoustic waves generated by sources located on the boundary. For medical diagnostic, it is important to recover the image of the acoustical medium and to determine the values of velocity, attenuation and density. In the paper, we describe a numerical experiment of visualization of several inclusions using the energy version of the reverse time migration (RTM). Certainly, the RTM image does not separate velocity and attenuation inclusions. However, kinematic and amplitude analysis gives a possibility to estimate values of the velocity and attenuation. As a result, we split the RTM image into two ones. Note that in this paper we consider the scalar value of sound velocity.

scholarly journals Phaseless Imaging by Reverse Time Migration: Acoustic Waves

2017 ◽  
Vol 10 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Zhiming Chen ◽  
Guanghui Huang
Keyword(s):  
Acoustic Waves ◽  
Numerical Experiments ◽  
Cross Correlation ◽  
Scattering Data ◽  
Imaging Method ◽  
Total Field ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Time Migration ◽  
Imaging Results

AbstractWe propose a reliable direct imaging method based on the reverse time migration for finding extended obstacles with phaseless total field data. We prove that the imaging resolution of the method is essentially the same as the imaging results using the scattering data with full phase information when the measurement is far away from the obstacle. The imaginary part of the cross-correlation imaging functional always peaks on the boundary of the obstacle. Numerical experiments are included to illustrate the powerful imaging quality

Reverse time migration of acoustic waves for imaging based defects detection for concrete and CFST structures

2019 ◽  
Vol 117 ◽  
pp. 210-220 ◽  
Author(s):  
Hai Liu ◽  
Huiyan Xia ◽  
Mingwei Zhuang ◽  
Zhijun Long ◽  
Chao Liu ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Time Migration

Reverse Time Migration Using the Pseudospectral Time-Domain Algorithm

2016 ◽  
Vol 24 (02) ◽  
pp. 1650005 ◽  
Author(s):  
Jiangang Xie ◽  
Zichao Guo ◽  
Hai Liu ◽  
Qing Huo Liu
Keyword(s):  
Time Domain ◽  
Acoustic Waves ◽  
Fdtd Method ◽  
Pseudospectral Method ◽  
Imaging Method ◽  
Processing Unit ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Eighth Order ◽  
Time Migration

We propose a pre-stack reverse time migration (RTM) seismic imaging method using the pseudospectral time-domain (PSTD) algorithm. Traditional pseudospectral method uses the fast Fourier transform (FFT) algorithm to calculate the spatial derivatives, but is limited by the wraparound effect due to the periodicity assumed in the FFT. The PSTD algorithm combines the pseudospectral method with a perfectly matched layer (PML) for acoustic waves. PML is a highly effective absorbing boundary condition that can eliminate the wraparound effect. It enables a wide application of the pseudospectral method to complex models. RTM based on the PSTD algorithm has advantages in the computational efficiency compared to traditional methods such as the second-order and high order finite difference time-domain (FDTD) methods. In this work, we implement the PSTD algorithm for acoustic wave equation based RTM. By applying the PSTD-RTM method to various seismic models and comparing it with RTM based on the eighth-order FDTD method, we find that PSTD-RTM method has better performance and saves more than 50% memory. The method is suitable for parallel computation, and has been accelerated by general purpose graphics processing unit.

scholarly journals Reverse time migration for extended obstacles: acoustic waves

2013 ◽  
Vol 29 (8) ◽  
pp. 085005 ◽  
Author(s):  
Junqing Chen ◽  
Zhiming Chen ◽  
Guanghui Huang
Keyword(s):  
Acoustic Waves ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Time Migration

3D angle gathers with plane-wave reverse-time migration

Geophysics ◽  
2013 ◽  
Vol 78 (2) ◽  
pp. S117-S123 ◽  
Author(s):  
Bing Tang ◽  
Sheng Xu ◽  
Yu Zhang
Keyword(s):  
Plane Wave ◽  
Low Cost ◽  
Seismic Events ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Amplitude Analysis ◽  
Time Migration ◽  
Shallow Seismic ◽  
Small Incidence ◽  
Promising Solution

Angle domain common image gathers (ADCIGs) from reverse-time migration (RTM) provide new tools for imaging complex geologic structures, such as salt flank or subsalt areas, characterized by multiarrivals. Compared with common image gathers from Kirchoff or Beam migration, the ADCIGs from RTM have the advantage of relying on wave propagation, providing a more reliable input for tomography or amplitude analysis. In practice however, most current wide azimuth surveys (e.g., deep-water regions of the Gulf of Mexico) are acquired with coarsely sampled shot and receiver locations on the surface, which leads to severe angular undersampling. This phenomenon is frequently observed on shallow seismic events in high-resolution 3D ADCIGs from common-shot RTM. In addition, because small offsets are frequently not recorded, seismic events are missing at small incidence angles in angle gathers. We have made a detailed study of the angular sampling issue in 3D angle gathers. We then used plane-wave RTM to generate 3D angle gathers. Plane-wave RTM, with its low-cost and automatic angular interpolation, is a promising solution for improving the quality of 3D angle gathers.

Finite‐element prestack reverse‐time migration for elastic waves

Geophysics ◽  
1989 ◽  
Vol 54 (9) ◽  
pp. 1204-1208 ◽  
Author(s):  
Yu‐chiung Teng ◽  
Ting‐fang Dai
Keyword(s):  
Acoustic Waves ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Initial Value ◽  
Depth Migration ◽  
Time Migration ◽  
Surface Data ◽  
Zero Offset ◽  
Dip Angle ◽  
Well Posed

Reverse‐time migration of zero‐offset data for acoustic waves has been successfully implemented by Whitmore (1983), Baysal et al. (1983), McMechan (1983), and Loewenthal and Mufti (1983). In reverse‐time migration, data recorded on the surface are used as the boundary condition and are extrapolated backward in time (Whitmore, 1983; Levin, 1984). Reverse‐time migration is mathematically a well‐posed problem. This is in contrast to conventional depth‐extrapolation‐migration schemes, in which the surface data are initial‐value conditions for solving the wave equation. Reverse‐time migration may offer improvements over conventional depth migration due to its freedom from dip‐angle limitations.

Determination of salt proximity by wave‐field imaging of transmitted energy

Geophysics ◽  
1988 ◽  
Vol 53 (8) ◽  
pp. 1109-1112 ◽  
Author(s):  
George A. McMechan ◽  
Liang‐Zie Hu ◽  
Douglas Stauber
Keyword(s):  
Acoustic Waves ◽  
Seismic Profile ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Vertical Seismic Profile ◽  
Wave Fields ◽  
Time Migration ◽  
Vsp Data ◽  
Field Imaging

Prestack reverse‐time migration for acoustic waves has recently been developed for vertical seismic profile (VSP) data (Chang and McMechan, 1986) and for cross‐hole (CH) data (Hu et al., 1988). Both sets of authors use the same migration software and produce images from the scattered (reflected and diffracted) energy in the recorded wave fields.

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