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Related papers: Thermoacoustic Tomography in Elastic Media

200 papers

We present a collection of well-conditioned integral equation methods for the solution of electrostatic, acoustic or electromagnetic scattering problems involving anisotropic, inhomogeneous media. In the electromagnetic case, our approach…

Numerical Analysis · Mathematics 2018-05-15 Lise-Marie Imbert-Gerard , Felipe Vico , Leslie Greengard , Miguel Ferrando

Model-based computational elasticity imaging of tissues can be posed as solving an inverse problem over finite elements spanning the displacement image. As most existing quasi-static elastography methods count on deterministic formulations…

Image and Video Processing · Electrical Eng. & Systems 2020-10-22 Narges Mohammadi , Marvin M. Doyley , Mujdat Cetin

We study the inverse problem of recovery a non-linearity $f(x,u)$, which is compactly supported in $x$, in the semilinear wave equation $u_{tt}-\Delta u+ f(x,u)=0$. We probe the medium with either complex or real-valued harmonic waves of…

Analysis of PDEs · Mathematics 2021-07-20 Antônio Sá Barreto , Plamen Stefanov

Consider the scattering of a time-harmonic acoustic plane wave by a bounded elastic obstacle which is immersed in a homogeneous acoustic medium. This paper concerns an inverse acoustic-elastic interaction problem, which is to determine the…

Numerical Analysis · Mathematics 2020-04-22 Heping Dong , Jun Lai , Peijun Li

Let $(\Omega,g)$ be a smooth compact two-dimensional Riemannian manifold with boundary, $\Lambda_g: f\mapsto \partial_\nu u|_{\partial\Omega}$ its DN map, where $u$ obeys $\Delta_g u=0$ in $\Omega$ and $u|_{\partial \Omega}=f$. The Electric…

Mathematical Physics · Physics 2020-09-18 M. I. Belishev , D. V. Korikov

We consider the reconstruction of the diffusion and absorption coefficients of the diffusion equation from the internal information of the solution obtained from the first step of the inverse photoacoustic tomography (PAT). In practice, the…

Analysis of PDEs · Mathematics 2021-09-22 Faouzi Triki , Qi Xue

In case of non-dissipative tissue the inverse problem of thermoacoustic imaging basically consists of two inverse problems. First, a function $\phi$ depending on the \emph{electromagnetic absorption function}, is estimated from one of three…

Analysis of PDEs · Mathematics 2010-09-23 Richard Kowar

Quantitative photoacoustic tomography (qPAT) is an imaging technique aimed at estimating chromophore concentrations inside tissues from photoacoustic images, which are formed by combining optical information and ultrasonic propagation. The…

Computational Physics · Physics 2019-12-23 Hwan Goh , Timo Lahivaara , Tanja Tarvainen , Aki Pulkkinen , Owen Dillon , Ruanui Nicholson , Jari Kaipio

In acousto-electric tomography the goal is to reconstruct the electric conductivity in a domain from electrostatic boundary measurements of corresponding currents and voltages, while the domain is penetrated by a time-dependent acoustic…

Medical Physics · Physics 2024-02-01 Bjørn Jensen , Adrian Kirkeby , Kim Knudsen

The amplitude equation for an unstable electrostatic wave is analyzed using an expansion in the mode amplitude $A(t)$. In the limit of weak instability, i.e. $\gamma\to 0^+$ where $\gamma$ is the linear growth rate, the nonlinear…

patt-sol · Physics 2009-10-30 John David Crawford , Anandhan Jayaraman

This paper is concerned with the problem of scattering of a time-harmonic electromagnetic field by a three-dimensional elastic body. General transmission conditions are considered to model the interaction between the electromagnetic field…

Analysis of PDEs · Mathematics 2019-08-27 Tielei Zhu , Jiaqing Yang , Bo Zhang

This is a continuation of our study [Uhlmann-Zhai, JMPA, 2021] on an inverse boundary value problem for a nonlinear elastic wave equation. We prove that all the linear and nonlinear coefficients can be recovered from the…

Analysis of PDEs · Mathematics 2024-01-25 Gunther Uhlmann , Jian Zhai

The time reversal method in thermoacoustic tomography is used for approximating the initial pressure inside a biological object using measurements of the pressure wave made on a surface surrounding the object. This article presents error…

Analysis of PDEs · Mathematics 2009-03-18 Yulia Hristova

In this work, the inverse problem of quantitative thermoacoustic tomography is studied. In quantitative thermoacoustic tomography, dielectric parameters of an imaged target are estimated from an absorbed energy density induced by an…

Computational Physics · Physics 2024-10-10 Teemu Sahlström , Timo Lähivaara , Tanja Tarvainen

Thermo- and photo- acoustic tomography require reconstructing initial acoustic pressure in a body from time series of pressure measured on a surface surrounding the body. For the classical case of free space wave propagation, various…

Analysis of PDEs · Mathematics 2015-06-23 B. Holman , L. Kunyansky

We consider the inverse source problem of thermo- and photoacoustic tomography, with data registered on an open surface partially surrounding the source of acoustic waves. Under the assumption of constant speed of sound we develop an…

Analysis of PDEs · Mathematics 2020-04-17 Mtthias Eller , Philip Hoskins , Leonid Kunyansky

This paper is concerned with time reversal in \emph{photoacoustic tomography} (PAT) of dissipative media that are similar to water. Under an appropriate condition, it is shown that the time reversal method in \cite{Wa11,AmBrGaWa11} based on…

Analysis of PDEs · Mathematics 2013-08-05 Richard Kowar

In photoacoustic imaging, ultrasound waves generated by a temperature rise after illumination of light absorbing structures are measured on the sample surface. These measurements are then used to reconstruct the optical absorption. We…

Applied Physics · Physics 2018-12-05 Oliver Lang , Peter Kovacs , Christian Motz , Mario Huemer , Thomas Berer , Peter Burgholzer

Standard photoacoustic tomography (PAT) provides data that consist of time-dependent signals governed by the wave equation, which are measured on an observation surface. In contrast, the measured data from the recently invented full-field…

Numerical Analysis · Mathematics 2024-06-10 Ngoc Do , Markus Haltmeier , Richard Kowar , Linh V. Nguyen , Robert Nuster

We derive closed-form solutions for reverberant elastography in anisotropic elastic media by adapting the framework used in electromagnetic theory to treat transverse isotropic materials. Different sample-setup geometries are analyzed,…

Medical Physics · Physics 2020-11-12 Luis A. Aleman-Castaneda , Fernando Zvietcovich , Kevin J. Parker