Time reversal elastography: A correlation tomography of complex shear wave field in soft solids.

2010 ◽  
Vol 127 (3) ◽  
pp. 1730-1730 ◽  
Author(s):  
Thomas Gallot ◽  
Stefan Catheline ◽  
Philippe Roux ◽  
Javier Brum ◽  
Carlos Negreira
Keyword(s):  
Wave Field ◽  
Shear Wave ◽  
Time Reversal ◽  
Soft Solids ◽  
Complex Shear

In‐vivo time reversal blastography: A passive correlation tomography of complex shear wave field within in soft tissues.

2010 ◽  
Vol 127 (3) ◽  
pp. 1730-1730
Author(s):  
Stefan Catheline ◽  
Thomas Gallot ◽  
Philippe Roux ◽  
Javier Brum ◽  
Carlos Negreira
Keyword(s):  
Wave Field ◽  
Shear Wave ◽  
Time Reversal ◽  
Soft Tissues ◽  
Complex Shear

1-D elasticity assessment in soft solids from shear wave correlation: the time-reversal approach

2009 ◽  
Vol 56 (11) ◽  
pp. 2400-2410 ◽  
Author(s):  
N. Benech ◽  
S. Catheline ◽  
J. Brum ◽  
T. Gallot ◽  
C. Negreira
Keyword(s):  
Shear Wave ◽  
Time Reversal ◽  
Soft Solids

Multiple sources array controls shear-wave field in soft tissue using time reversal

2018 ◽  
Vol 63 (18) ◽  
pp. 18NT02
Author(s):  
C Zemzemi ◽  
J Aichele ◽  
S Catheline
Keyword(s):  
Soft Tissue ◽  
Wave Field ◽  
Shear Wave ◽  
Time Reversal ◽  
Multiple Sources

An initial study of complete 2D shear wave dispersion images using a reverberant shear wave field

2019 ◽  
Vol 64 (14) ◽  
pp. 145009 ◽  
Author(s):  
Juvenal Ormachea ◽  
Kevin J Parker ◽  
Richard G Barr
Keyword(s):  
Wave Field ◽  
Shear Wave ◽  
Wave Dispersion ◽  
Initial Study

scholarly journals Shear Wave Elastography Based on Noise Correlation and Time Reversal

2021 ◽  
Vol 9 ◽  
Author(s):  
Javier Brum ◽  
Nicolás Benech ◽  
Thomas Gallot ◽  
Carlos Negreira
Keyword(s):  
Shear Wave ◽  
Time Reversal ◽  
Shear Waves ◽  
Shear Wave Elastography ◽  
Noise Correlation ◽  
Elasticity Imaging ◽  
Physiological Noise ◽  
Wave Source ◽  
Imaging Device ◽  
Shear Elasticity

Shear wave elastography (SWE) relies on the generation and tracking of coherent shear waves to image the tissue's shear elasticity. Recent technological developments have allowed SWE to be implemented in commercial ultrasound and magnetic resonance imaging systems, quickly becoming a new imaging modality in medicine and biology. However, coherent shear wave tracking sets a limitation to SWE because it either requires ultrafast frame rates (of up to 20 kHz), or alternatively, a phase-lock synchronization between shear wave-source and imaging device. Moreover, there are many applications where coherent shear wave tracking is not possible because scattered waves from tissue’s inhomogeneities, waves coming from muscular activity, heart beating or external vibrations interfere with the coherent shear wave. To overcome these limitations, several authors developed an alternative approach to extract the shear elasticity of tissues from a complex elastic wavefield. To control the wavefield, this approach relies on the analogy between time reversal and seismic noise cross-correlation. By cross-correlating the elastic field at different positions, which can be interpreted as a time reversal experiment performed in the computer, shear waves are virtually focused on any point of the imaging plane. Then, different independent methods can be used to image the shear elasticity, for example, tracking the coherent shear wave as it focuses, measuring the focus size or simply evaluating the amplitude at the focusing point. The main advantage of this approach is its compatibility with low imaging rates modalities, which has led to innovative developments and new challenges in the field of multi-modality elastography. The goal of this short review is to cover the major developments in wave-physics involving shear elasticity imaging using a complex elastic wavefield and its latest applications including slow imaging rate modalities and passive shear elasticity imaging based on physiological noise correlation.

scholarly journals Shear-wave generation from cavitation in soft solids

2019 ◽  
Vol 114 (12) ◽  
pp. 123702 ◽  
Author(s):  
J. Rapet ◽  
Y. Tagawa ◽  
C. D. Ohl
Keyword(s):  
Shear Wave ◽  
Wave Generation ◽  
Soft Solids

scholarly journals Finite-difference modelling to evaluate seismic P-wave and shear-wave field data

Solid Earth ◽  
2015 ◽  
Vol 6 (1) ◽  
pp. 33-47 ◽  
Author(s):  
T. Burschil ◽  
T. Beilecke ◽  
C. M. Krawczyk
Keyword(s):  
Wave Field ◽  
Shear Wave ◽  
Field Data ◽  
P Wave ◽  
Sh Wave ◽  
Surface Shear ◽  
Near Surface ◽  
Reflection Seismic ◽  
Surface Shear Wave ◽  
Seismic Measurements

Abstract. High-resolution reflection seismic methods are an established non-destructive tool for engineering tasks. In the near surface, shear-wave reflection seismic measurements usually offer a higher spatial resolution in the same effective signal frequency spectrum than P-wave data, but data quality varies more strongly. To discuss the causes of these differences, we investigated a P-wave and a SH-wave seismic reflection profile measured at the same location on the island of Föhr, Germany and applied seismic reflection processing to the field data as well as finite-difference modelling of the seismic wave field. The simulations calculated were adapted to the acquisition field geometry, comprising 2 m receiver distance (1 m for SH wave) and 4 m shot distance along the 1.5 km long P-wave and 800 m long SH-wave profiles. A Ricker wavelet and the use of absorbing frames were first-order model parameters. The petrophysical parameters to populate the structural models down to 400 m depth were taken from borehole data, VSP (vertical seismic profile) measurements and cross-plot relations. The simulation of the P-wave wave-field was based on interpretation of the P-wave depth section that included a priori information from boreholes and airborne electromagnetics. Velocities for 14 layers in the model were derived from the analysis of five nearby VSPs (vP =1600–2300 m s-1). Synthetic shot data were compared with the field data and seismic sections were created. Major features like direct wave and reflections are imaged. We reproduce the mayor reflectors in the depth section of the field data, e.g. a prominent till layer and several deep reflectors. The SH-wave model was adapted accordingly but only led to minor correlation with the field data and produced a higher signal-to-noise ratio. Therefore, we suggest to consider for future simulations additional features like intrinsic damping, thin layering, or a near-surface weathering layer. These may lead to a better understanding of key parameters determining the data quality of near-surface shear-wave seismic measurements.

Validation of Magnetic Resonance Elastography by Dynamic Shear Testing in the Shear Wave Regime

2010 ◽  
Author(s):  
Ruth J. Okamoto ◽  
Erik H. Clayton ◽  
Kate S. Wilson ◽  
Philip V. Bayly
Keyword(s):  
Magnetic Resonance ◽  
Shear Modulus ◽  
Shear Wave ◽  
Shear Force ◽  
Magnetic Resonance Elastography ◽  
Dynamic Shear ◽  
Complex Shear Modulus ◽  
Shear Testing ◽  
Complex Shear ◽  
Propagating Shear

Magnetic resonance elastography (MRE) is a novel experimental technique for probing the dynamic shear modulus of soft biological tissue non-invasively and in vivo. MRE utilizes a standard MRI scanner to acquire images of propagating shear waves through a specimen that is subject to external harmonic mechanical actuation; commonly at frequencies in excess of 200Hz. At steady state, the wavelength of the propagating shear wave can be used to estimate the shear modulus of the tissue. Dynamic shear testing (DST) is also used to characterize soft biomaterials. Thin samples of the material are subject to oscillatory shear strains. Shear force is measured, and converted to shear stress — analysis of this data of a range of frequencies gives a complex shear modulus. The data analysis method assumes that the shear displacement is linear and shear strain is constant through the thickness of the sample. In soft tissues, very thin samples are typically used to avoid inertial effects at higher frequencies. As the thickness of the sample decreases, it is more difficult to cut samples of uniform thickness and to maintain structural integrity of the sample. Thus in practice, measurements of brain tissue properties using DST without inertial correction are limited to low frequencies. In this work, we bridge the frequency regimes of DST and MRE by testing thick samples using DST over a range of frequencies that generates a shear wave in the sample, with a corresponding peak in the measured shear force. The frequency and magnitude of this peak give additional information about the complex shear modulus of the material being tested, and these DST results are interpreted using a finite element (FE) model of the sample. Using this method, we can obtain an estimate of shear modulus in an intermediate frequency regime between that of standard DST and MRE.

Study of elastic nonlinearity of soft solids with transient elastography: Landau coefficients and finite amplitude shear wave

2002 ◽  
Vol 112 (5) ◽  
pp. 2404-2405
Author(s):  
Stefan Catheline ◽  
Jean‐Luc Gennisson ◽  
Sana Chaffa ◽  
Mathias Fink
Keyword(s):  
Shear Wave ◽  
Transient Elastography ◽  
Finite Amplitude ◽  
Soft Solids ◽  
Elastic Nonlinearity
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