Finite-element-based photoacoustic tomography: phantom and chicken bone experiments

Abstract

We describe a photoacoustic image reconstruction algorithm that is based on the finite-element solution to the photoacoustic wave equation in the frequency domain. Our reconstruction approach is an iterative Newton method coupled with combined Marquardt and Tikhonov regularizations that can extract the spatial distribution of optical-absorption property in heterogeneous media. We demonstrate this algorithm by using phantom and chicken bone measurements from a circular scanning photoacoustic tomography system. The results obtained show that millimeter-sized phantom objects and chicken bones and/or joints can be clearly detected using our finite-element-based photoacoustic tomography method.

Photoacoustic Tomography

“…Due to the use of an effective reconstruction algorithm, PAT is able to improve the resolution limitation and to realize quantitative imaging. Phantom and in vivo experiments have shown that model-based reconstruction methods, including k-space and finite element based, are able to recover both structural and functional information on biological tissues [18][19][20][21][22].…”

Quantitative photoacoustic tomography: recovery of optical absorption coefficient maps of heterogeneous media

“…The first is to obtain the map of absorbed optical energy density through a model-based reconstruction algorithm that is based on finite element solution to the PA wave equation in frequency domain subject to the radiation or absorbing boundary conditions (BCs). [12][13][14] The second step is to recover the distribution of optical absorption coefficient from the absorbed energy density obtained from the first step based on the finite element solution to the photon diffusion equation. Since our reconstruction algorithm for the first step has been described in detail elsewhere, 12-14 we give a brief outline here in order to couple the second step (i.e., the photon diffusion equation) with the first step.…”

“…12,14 Briefly, pulsed light from a Nd: YAG laser (wavelength: 532nm, pulse duration: 3-6ns) were coupled into the phantom via an optical subsystem and generated acoustic signals. The transducer and phantom were immersed in a water tank.…”

Three-dimensional photoacoustic tomography based on graphics-processing-unit-accelerated finite element method

“…Moreover, the heterogeneous acoustic wave equation cannot be solved analytically. To overcome these limitations, the finite element (FEM) based reconstruction algorithm was proposed by Yuan and co-workers [2,[7][8][9][10][11][12]. With the FEM-based method, arbitrary measurement configurations can be used for data collection.…”