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4th International Conference on Photonics and Imaging in Biology and Medicine

作者： Song, Zhiyuan Jiang, Jingying Wang, Ruikang K. Zhang, Fan Yao, Jianquan Tianjin Univ Inst Laser & Optoelect Coll Precis Instrument & Optoelect Engn Tianjin 300072 Peoples R China Oregon Hlth & Sci Univ Dept Biomed Engn Beaverton OR 97006 USA Tianjin Univ Coll Precis Instruments & Opto Elect Engn Dept Biomed Engn Tianjin 300072 Peoples R China

ISBN: (纸本)081946080X

The photoacoustic (PA) effect refers to the generation of acoustic waves by the modulated optical radiation. A novel tissue imaging technique, photoacoustic imaging is using the acoustic waves made in the PA effect to reconstruct the sample. It whose characteristic is combining the advantages of pure optical imaging and pure ultrasound imaging can map the high contrast and high spatial resolution tissue image. The PA imaging reconstruction algorithm performing the signal filtering operation first and then to reduce the signal data to the image, has the important influence on the quality of the image made by the experiment of PA. With the laser appearance in 1960s, the PA imaging technique made great advance and the reconstruction algorithm gains quick development. The prevalent PA reconstruction algorithms include Kruger's 3D inverse Radon transform, Frenz's Fourier transform, Lihong Wang's method based on the analytic solution. Nowadays, PA imaging technique develops to the real-time PA image. So to choose a suitable fast algorithm is significant to the PA imaging system's application. We will review the current PA imaging reconstruction algorithm and compare them in the aspect of the tissue imaging spatial resolution and so on.

关键词： pA imaging reconstruction algorithm spatial resolution tissue

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Improved reconstruction algorithm for luminescence optical tomography when background lumiphore is present

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APPLIED OPTICS 1998年第16期37卷 3547-3552页

作者： Chang, J Graber, HL Barbour, RL SUNY Hlth Sci Ctr Dept Pathol Brooklyn NY 11203 USA SUNY Hlth Sci Ctr Program Physiol & Biophys Brooklyn NY 11203 USA

We examine the impact of background lumiphore on image quality in luminescence optical tomography. A modification of a previously described algorithm [J. Chang, H. L. Graber, and R. L. Barbour, J. Opt. Sec. Am. A 14, 288-299 (1997);J. Chang, H. L. Graber, and R. L. Barbour, IEEE Trans. Biomed. Eng. 44, 810-822 (1997)] that estimates the background luminescence directly from the detector readings is developed. Numerical simulations were performed to calculate the diffusion-regime limiting form of forward-problem solutions for a specific test medium. We performed image reconstructions with and without white noise added to the detector readings, using both the original and the improved versions of the algorithm. The results indicate that the original version produces unsatisfactory reconstructions when background lumiphore is present, whereas the improved algorithm yields qualitatively better images, especially for small target-to-background luminescence yield ratios. (C) 1998 Optical Society of America.

关键词： reconstruction algorithm luminescence iodine reading image reconstruction white noise America Image quality PROBLEM SOLUTION

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Model-driven CT reconstruction algorithm for nano-resolution x-ray phase contrast imaging

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Chinese Physics B 2024年第7期33卷 646-650页

作者：谭雨航蔡学宝杨杰成苏婷郑海荣梁栋朱佩平葛永帅 Research Center for Medical Artificial Intelligence Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Institute of Electronic Paper Displays South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou 510006China Paul C Lauterbur Research Center for Biomedical Imaging Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

The low-density imaging performance of a zone plate-based nano-resolution hard x-ray computed tomography(CT)system can be significantly improved by incorporating a grating-based Lau interferometer. Due to the diffraction, however,the acquired nano-resolution phase signal may suffer splitting problem, which impedes the direct reconstruction of phase contrast CT(nPCT) images. To overcome, a new model-driven nPCT image reconstruction algorithm is developed in this study. In it, the diffraction procedure is mathematically modeled into a matrix B, from which the projections without signal splitting can be generated invertedly. Furthermore, a penalized weighted least-square model with total variation(PWLSTV) is employed to denoise these projections, from which nPCT images with high accuracy are directly *** experiments demonstrate that this new algorithm is able to work with phase projections having any splitting distances. Moreover, results also reveal that nPCT images of higher signal-to-noise-ratio(SNR) could be reconstructed from projections having larger splitting distances. In summary, a novel model-driven nPCT image reconstruction algorithm with high accuracy and robustness is verified for the Lau interferometer-based hard x-ray nano-resolution phase contrast imaging.

关键词： splitting phase image reconstruction algorithm grating interferometer

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A reconstruction algorithm for electrical impedance tomography based on sparsity regularization

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INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 2012年第3期89卷 337-353页

作者： Jin, Bangti Khan, Taufiquar Maass, Peter Texas A&M Univ Dept Math College Stn TX 77843 USA Texas A&M Univ Inst Appl Math & Computat Sci College Stn TX 77843 USA Clemson Univ Dept Math Sci Clemson SC 29634 USA Univ Bremen Ctr Ind Math D-28334 Bremen Germany

This paper develops a novel sparse reconstruction algorithm for the electrical impedance tomography problem of determining a conductivity parameter from boundary measurements. The sparsity of the inhomogeneity with respect to a certain basis is a priori assumed. The proposed approach is motivated by a Tikhonov functional incorporating a sparsity-promoting l1-penalty term, and it allows us to obtain quantitative results when the assumption is valid. A novel iterative algorithm of soft shrinkage type was proposed. Numerical results for several two-dimensional problems with both single and multiple convex and nonconvex inclusions were presented to illustrate the features of the proposed algorithm and were compared with one conventional approach based on smoothness regularization. Copyright (c) 2011 John Wiley & Sons, Ltd.

关键词： electrical impedance tomography reconstruction algorithm sparsity regularization

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Image reconstruction algorithm based on the extended regularised total least squares method for electrical capacitance tomography

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IET SCIENCE MEASUREMENT & TECHNOLOGY 2008年第5期2卷 326-336页

作者： Lei, J. Liu, S. Li, Z. H. Sun, M. Chinese Acad Sci Inst Engn Thermophys Beijing 100080 Peoples R China N China Elect Power Univ Sch Energy & Power Engn Beijing 102206 Peoples R China

Electrical capacitance tomography (ECT) is a non-invasive imaging technology that aims at the visualisation of the cross-sectional permittivity distribution of a dielectric object based on the measured capacitance data. Successful applications of ECT depend greatly on the precision and speed of the image reconstruction algorithms. ECT image reconstruction is a typical ill-posed problem, and its solution is unstable, that is, the solution is sensitive to noises in the input data. Methods that ensure the stability of a solution while enhancing the quality of the reconstructed images should be used to obtain a meaningful reconstruction result. An image reconstruction algorithm based on the regularised total least squares (TLS) method that considers the errors in both the sensitivity field matrix and the capacitance data for ECT is presented. The regularised TLS method is extended using a combination robust estimation technique and an extended stabilising functional according to the ill-posed characteristics of ECT, which transforms the image reconstruction problem into an optimisation problem. In addition, the Newton algorithm is employed to solve the objective functional. Numerical simulations indicate that the algorithm is feasible and overcomes the numerical instability of ECT image reconstruction;for the cases of the reconstructed objects considered here, the spatial resolution of the reconstructed images obtained using the algorithm is enhanced;as a result, an efficient method for ECT image reconstruction is introduced.

关键词： image reconstruction Electrical capacitance tomography algorithms reconstruction algorithm

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Sizing of Defect Using Magnetic Memory Signal Based on the reconstruction algorithm

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IEEE ACCESS 2018年 6卷 58543-58548页

作者： Li, Hongmei Wang, Yu Huang, Ranran Zhang, Fuchen Yang, Bin North Minzu Univ Sch Mech Engn Yinchuan 750021 Peoples R China

A metal magnetic memory (MMM) testing technique is an extensively used qualitative method for locating the position of possible damages in ferromagnetic metal structures. The mechanism of the MMM technique is described by the magnetomechanical effect under the constant magnetizing field of the Earth. Discontinuous defect remarkably affects MMM signals. For the exploration of the influences of defect on MMM signals and the determination of a method to size the defect, experimentation and reconstruction calculation were performed in this paper. Stress was imported into a specimen fabricated with a circular defect to generate the stress-induced MMM signal. The defect size and the residual magnetic field of the specimen were measured after loading. The stress-induced magnetization inside the specimen was reconstructed with measured magnetic field signals using a reconstruction algorithm. The influences of the discontinuous defect on the stress-induced magnetization were quantitatively analyzed. A method for defect imaging and sizing using the MMM technique was proposed. Results corroborate that the reconstructed defect width is congruent with the actual defect width, thereby confirming the effectiveness and applicability of the proposed method.

关键词： Defect sizing metal magnetic memory testing magneto-mechanical effect reconstruction algorithm

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VOIR, a volumetric image reconstruction algorithm based on Fourier techniques for inversion of the 3-D radon transform

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IEEE TRANSACTIONS ON IMAGE PROCESSING 1996年第1期5卷 121-131页

作者： Dusaussoy, NJ Advanced Research and Application Corporation Sunnyvale CA USA

A novel volumetric image reconstruction algorithm known as VOIR is presented for inversion of the 3-D Radon transform or its radial derivative, The algorithm is a direct implementation of the projection slice theorem for plane integrals, It generalizes one of the most successful method in 2-D Fourier image reconstruction involving concentric-square rasters to 3-D;in VOIR, the spectral data, which is calculated by fast Fourier techniques, lie on concentric cubes and are interpolated by a bilinear method on the sides of these concentric cubes. The algorithm has great computational advantages over bite red-backprojection algorithms;for images of side dimension N, the numerical complexity of VOIR is O(N-3 log N) instead of O(N-4) for backprojection techniques, An evaluation of the image processing performance is reported by comparison of reconstructed images from simulated cone-beam scans of a contrast and resolution test object, The image processing performance is also characterized by an analysis of the edge response from the reconstructed images.

关键词： reconstruction algorithm algorithms image reconstruction Radon transforms Fourier Three Dimensions Cube Inversion

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An implementation of the reconstruction algorithm of A Nachman for the 2D inverse conductivity problem

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INVERSE PROBLEMS 2000年第3期16卷 681-699页

作者： Siltanen, S Mueller, J Isaacson, D Helsinki Univ Technol FIN-02150 Espoo Finland Rensselaer Polytech Inst Troy NY USA

The 2D inverse conductivity problem requires one to determine the unknown electrical conductivity distribution inside a bounded domain Omega subset of R-2 from knowledge of the Dirichlet-to-Neumann map. The problem has geophysical, industrial, and medical imaging (electrical impedance tomography) applications. In 1996 A Nachman proved that the Dirichlet-to-Neumann map uniquely determines C-2 conductivities. The proof, which is constructive, outlines a direct method for reconstructing the conductivity. In this paper we present an implementation of the algorithm in Nachman's proof. The paper includes numerical results obtained by applying the general algorithms described to two radially symmetric cases of small and large contrast.

关键词： .assume Inverse Problems reconstruction algorithm conductivities inverse conductivity electrical impedance Dirichlet-to-Neumann algorithm of Nachman uniquely Nachman proof

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Research on 3D reconstruction algorithm of Medical CT Image Based on Parallel Contour

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IEEE SENSORS JOURNAL 2020年第20期20卷 11828-11835页

作者： Zhao, Wei Wang, Lina Qiqihar Med Univ Affiliated Hosp 3 Radiol Dept Qiqihar 161000 Peoples R China Qiqihar Med Univ Affiliated Hosp 3 Dept Hematol Oncol Qiqihar 161000 Peoples R China

The current three-dimensional reconstruction algorithm of medical CT images still has certain drawbacks, and it is difficult to apply it effectively to clinical practice. In view of this, based on the parallel contour line, this paper studies the three-dimensional reconstruction algorithm of medical CT image, and realizes the three-dimensional reconstruction of the aortic dissection by surface drawing and volume rendering. At the same time, through the three modules of image preprocessing, aortic segmentation, dissection segmentation and three-dimensional reconstruction, the three-dimensional reconstruction of the patient's aortic dissection is realized. The reconstructed three-dimensional aortic dissection model can observe the shape of the internal sandwich model directly through the aortic wall, and the display of the three-dimensional structure of the interlayer is more intuitive and clearer. Finally, this paper designs experiments to analyze the performance of the algorithm. The research indicates that the three-dimensional reconstruction algorithm of medical CT images proposed in this paper has certain clinical effects and can provide theoretical reference for subsequent related research.

关键词： Image reconstruction Three-dimensional displays Medical diagnostic imaging Image segmentation Computed tomography Solid modeling reconstruction algorithm medical diagnosis image processing

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New reconstruction algorithm for moire tomography in flow field measurements

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OPTICAL ENGINEERING 2006年第11期45卷 117002-1-117002页

作者： Zhang, Bin Song, Yang Song, Yizhong He, Anzhi Nanjing Univ Sci & Technol Dept Informat Phys & Engn Nanjing 210094 Peoples R China

A new iterative reconstruction algorithm is developed and applied to moire deflection tomography for flow field measurements. The algorithm is derived from the basic deflection formula and based on a modified algebraic reconstruction technique. The precision and convergence of the algorithm are analyzed through a numerical simulation. To capture multidirectional projection data, a rotatable deflectometric system is developed. The efficacy of the new algorithm is assessed by reconstructing an asymmetric temperature field. Furthermore, the algorithm is employed to investigate the image of a cross section of a free jet containing steep gradients and to reconstruct the density field of the rocket exhausted jet. (c) 2006 Society of Photo-Optical Instrumentation Engineers.

关键词： reconstruction algorithm moire deflectometry tomography flow field

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