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We study the inverse problem of determining both the source of a wave and its speed inside a medium from measurements of the solution of the wave equation on the boundary. This problem arises in photoacoustic and thermoacoustic tomography,…

Analysis of PDEs · Mathematics 2019-06-18 Christina Knox , Amir Moradifam

Quantitative Photoacoustic tomography (QPAT) is an emerging medical imaging modality which offers the possibility of combining the high resolution of the acoustic waves and large contrast of optical waves by quantifying the molecular…

Numerical Analysis · Mathematics 2014-10-30 Adriano De Cezaro , Fabiana Travessini De Cezaro

A novel approach to improving the performances of confocal scanning imaging is proposed. We experimentally demonstrate its feasibility using acoustic waves. It relies on a new way to encode spatial information using the temporal dimension.…

The inversion of linear systems is a fundamental step in many inverse problems. Computational challenges exist when trying to invert large linear systems, where limited computing resources mean that only part of the system can be kept in…

Distributed, Parallel, and Cluster Computing · Computer Science 2017-09-05 Yushan Gao , Thomas Blumensath

This paper surveys inverse problems arising in several coupled-physics imaging modalities for both medical and geophysical purposes. These include Photo-acoustic Tomography (PAT), Thermo-acoustic Tomography (TAT), Electro-Seismic…

Analysis of PDEs · Mathematics 2016-08-12 Ilker Kocyigit , Ru-Yu Lai , Lingyun Qiu , Yang Yang , Ting Zhou

An efficient and accurate image reconstruction algorithm for ultrasound tomography (UST) is described and demonstrated, which can recover accurate sound speed distribution from acoustic time series measurements made in soft tissue. The…

Numerical Analysis · Mathematics 2021-11-17 Ashkan Javaherian , Ben Cox

Exterior inverse problem for the circular means transform (CMT) arises in the intravascular photoacoustic imaging (IVPA), in the intravascular ultrasound imaging (IVUS), as well as in radar and sonar. The reduction of the IPVA to the CMT is…

Analysis of PDEs · Mathematics 2013-08-29 Gaik Ambartsoumian , Leonid Kunyansky

Objective:Optoacoustic (photoacoustic) tomography is aimed at reconstructing maps of the initial pressure rise induced by the absorption of light pulses in tissue. In practice, due to inaccurate assumptions in the forward model, noise and…

Medical Physics · Physics 2019-01-21 Jaya Prakash , Subhamoy Mandal , Daniel Razansky , Vasilis Ntziachristos

In photoacoustic imaging the objective is to determine the optical properties of biological tissue from boundary measurement of the generated acoustic wave. Here, we propose a restriction to piecewise constant media parameters. Precisely we…

Analysis of PDEs · Mathematics 2024-07-09 Yavar Kian , Faouzi Triki

We propose a new reverse time migration method for reconstructing extended obstacles in the planar waveguide using acoustic waves at a fixed frequency. We prove the resolution of the reconstruction method in terms of the aperture and the…

Classical Physics · Physics 2015-10-28 Zhiming Chen , Guanghui Huang

The problem of object restoration in the case of spatially incoherent illumination is considered. A regularized solution to the inverse problem is obtained through a probabilistic approach, and a numerical algorithm based on the statistical…

Optics · Physics 2009-11-13 Enrico De Micheli , Giovanni Alberto Viano

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

Motivated by applications in imaging nonlinear optical absorption by photoacoustic tomography (PAT), we study in this work inverse coefficient problems for a semilinear radiative transport equation and its diffusion approximation with…

Analysis of PDEs · Mathematics 2021-07-20 Ru-Yu Lai , Kui Ren , Ting Zhou

We investigate the problem of recovering the initial displacement f for a solution u of a linear, isotropic, non-homogeneous elastic wave equation, given measurements of u on [0,T] x \partial \Omega, where \Omega\subset\R^3 is some bounded…

Analysis of PDEs · Mathematics 2015-05-28 Justin Tittelfitz

We describe a new algorithm to solve a particular phase retrieval problem, that has wide applications in audio processing: the reconstruction of a function from its scalogram, that is from the modulus of its wavelet transform. It is a…

Optimization and Control · Mathematics 2017-04-11 Irène Waldspurger

We consider a particular approach to the regularization of the inverse problem of computerized tomography. This approach is based on notions pertaining to Fourier synthesis. It refines previous contributions, in which the preprocessing of…

Optimization and Control · Mathematics 2014-01-30 Pierre Maréchal , Abdelhadi Elasmai

We consider the problem of signal reconstruction for computed tomography (CT) under a nonlinear forward model that accounts for exponential signal attenuation, a polychromatic X-ray source, general measurement noise (e.g., Poisson shot…

Image and Video Processing · Electrical Eng. & Systems 2026-02-12 Mengqi Lou , Kabir Aladin Verchand , Sara Fridovich-Keil , Ashwin Pananjady

Hyperspectral neutron computed tomography is a tomographic imaging technique in which thousands of wavelength-specific neutron radiographs are measured for each tomographic view. In conventional hyperspectral reconstruction, data from each…

We develop a mathematical and numerical framework to solve state estimation problems for applications that present variations in the shape of the spatial domain. This situation arises typically in a biomedical context where inverse problems…

Numerical Analysis · Mathematics 2023-03-14 Felipe Galarce , Damiano Lombardi , Olga Mula

We study the uniqueness and accuracy of the numerical solution of the problem of reconstruction of the shape and trajectory of a reflecting obstacle moving in an inhomogeneous medium from travel times, start and end points, and initial…

Data Structures and Algorithms · Computer Science 2014-01-17 Kamen M. Lozev
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