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A novel reconstruction algorithm based on density clustering for cosmic-ray muon scattering inspection

NUCLEAR ENGINEERING AND TECHNOLOGY 2021年第7期53卷 2348-2356页

作者： Hou, Linjun Zhang, Quanhu Yang, Jianqing Cai, Xingfu Yao, Qingxu Huo, Yonggang Chen, Qifan Xian Res Inst Hitech Xian 710025 Peoples R China Spallat Neutron Source Sci Ctr Dongguan 523803 Guangdong Peoples R China

As a relatively new radiation imaging method, the cosmic-ray muon scattering imaging technology can be used to prevent nuclear smuggling and is of considerable significance to nuclear safety. Proposed in this paper is a new reconstruction algorithm based on density clustering, aiming to improve inspection quality with better performance. Firstly, this new algorithm is introduced in detail. Then in order to eliminate the inequity of the density threshold caused by the heterogeneity of the muon flux in different positions, a new flux correction method is proposed. Finally, three groups of simulation experiments are carried out with the help of Geant4 toolkit to optimize the algorithm parameters, verify the correction method and test the inspection quality under shielded condition, and compare this algorithm with another common inspection algorithm under different conditions. The results show that this algorithm can effectively identify and locate nuclear material with low misjudging and missing rates even when there is shielding and momentum precision is low, and the threshold correcting method is universally effective for density clustering algorithms. (c) 2021 Korean Nuclear Society, Published by Elsevier Korea LLC. This is an open access article under the CC BY-NC-ND license (http://***/licenses/by-nc-nd/4.0/).

关键词： Radiation imaging reconstruction algorithm Cosmic-ray muon Nuclear safety

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Channel Estimation Based on Dual-path reconstruction algorithm 2021

Channel Estimation Based on Dual-path Reconstruction Algorit...

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2nd International Conference on Artificial Intelligence and Information Systems (ICAIIS )

作者： Han, Mingzhi An, Chengquan Gao, Bo Harbin Engn Univ Coll Informat & Commun Engn Harbin Peoples R China

ISBN: (纸本)9781450390200

In the sparse channel estimation of Orthogonal Frequency Division Multiplexing (OFDM) systems, for any delay of the multipath channels, most of the channel estimation algorithms based on Compressed Sensing (CS) have only one estimate. In view of this situation, a Dual-path reconstruction (DR) algorithm is proposed based on the Orthogonal Matching Pursuit with Binary-search Refinement (OMPBR) algorithm. When locating a time delay in the actual channel, the algorithm provides two estimators to estimate the time delay. Ideally, the actual time delay is in the middle of the two estimators, and the errors of the two estimators cancel each other out. Through theoretical analysis and simulation results, it is confirmed that the accuracy of channel estimation achieved by the DR algorithm is higher than that achieved by the OMPBR algorithm.

关键词： OFDM channel estimation compressed sensing reconstruction algorithm

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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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Ordered subset expectation maximisation vs Bayesian penalised likelihood reconstruction algorithm in 18F-PSMA-1007 PET/CT

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ANNALS OF NUCLEAR MEDICINE 2020年第3期34卷 192-199页

作者： Witkowska-Patena, Ewa Budzynska, Anna Gizewska, Agnieszka Dziuk, Miroslaw Walecka-Mazur, Agata Mil Inst Med Dept Nucl Med 128 Szaserow St PL-04141 Warsaw Poland Affidea Mazovian PET CT Med Ctr 128 Szaserow St PL-04349 Warsaw Poland Synektik Pharma Kielce Poland

Background The aim of the study was to compare widely used ordered subset expectation maximisation (OSEM) algorithm with a new Bayesian penalised likelihood (BPL) *** algorithm in 18F-PSMA-1007 PET/CT. Methods We retrospectively assessed 25 18F-PSMA-1007 PET/CT scans with both OSEM and *** reconstructions available. Each scan was independently reported by two physicians both in OSEM and ***. SUVmax, SUVmean and tumour-to-background ratio (TBR) of each lesion were measured. Reports were also compared for their final conclusions and the number and localisation of lesions. Results In both reconstructions the same 87 lesions were reported. Mean SUVmax, SUVmean and TBR were higher for *** than OSEM (7.01 vs 6.53 [p = 0.052], 4.16 vs 3.84 [p = 0.036] and 20.2 vs 16.8 [p < 0.00001], respectively). Small lesions (< 10 mm) had statistically significant higher SUVmax, SUVmean and TBR in *** than OSEM (5.37 vs 4.79 [p = 0.032], 3.08 vs 2.70 [p = 0.04] and 15.5 vs 12.5 [p = 0.00214], respectively). For lesions >= 10 mm, no significant differences were observed. Findings with higher tracer avidity (SUVmax >= 5) tended to have higher SUVmax, SUVmean and TBR values in *** (11.6 vs 10.3 [p = 0.00278], 7.0 vs 6.7 [p = 0.077] and 33.9 vs 26.7 [p < 0.00001, respectively). Mean background uptake did not differ significantly between *** and OSEM (0.42 vs 0.39, p = 0.07). Conclusions In 18F-PSMA-1007 PET/CT, *** SUVs and TBR tend to be higher (regardless of lesion localisation), especially for small and highly avid lesions. Increase in SUVs is also higher for lesions with high tracer uptake. Still, *** does not affect 18F-PSMA-1007 PET/CT specificity and sensitivity.

关键词： 18F-PSMA-1007 PET CT Prostate cancer Q Clear OSEM reconstruction algorithm

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A super-resolution reconstruction algorithm for two-photon fluorescence polarization microscopy

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OPTICS COMMUNICATIONS 2021年 499卷 127116-127116页

作者： Xu, Dongdong Wang, Xiao Xu, Zhibing Zhou, Wenxia Yin, Jianhua Nanjing Univ Aeronaut & Astronaut Dept Biomed Engn Nanjing 210016 Jiangsu Peoples R China

Two-photon fluorescence polarization microscopy is widely used to monitor the orientation and structural information of biomolecules labeled by fluorescence dipoles, while suffering from the spatial resolution limitation. In this paper, we propose an effective reconstruction algorithm for two-photon fluorescence polarization microscopy to reconstruct the super-resolution image and obtain the finer orientation information of dipoles at corresponding super-resolution scale. First, a conventional statistic model is employed to characterize the orientation distribution of dipole-clusters. By combining the model with the two-photon microscope imaging theory, then an optimization model is proposed and the reconstruction algorithm is developed based on conjugate gradient least square method and applied to various samples. The reconstruction results demonstrate that the imaging resolution of 90 nm can be reached and the finer orientation distribution information of dipole-clusters at the corresponding resolution can be obtained. Finally, Monte Carlo analysis has been performed, which verifies that the algorithm has high accuracy in reconstructing the parameters of the finer orientation distribution of dipole-clusters. The analysis of sample noise proves that the reconstruction algorithm can be utilized to actual samples within the appropriate noise range.

关键词： Two-photon fluorescence polarization Super resolution Dipole orientation distribution reconstruction algorithm

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A least squares support vector regression coupled linear reconstruction algorithm for ECT

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FLOW MEASUREMENT AND INSTRUMENTATION 2021年 77卷 101874-101874页

作者： Xie, Huangjun Xia, Tao Tian, Zenan Zheng, Xudong Zhang, Xiaobin Zhejiang Univ Inst Refrigerat & Cryogen Hangzhou 310027 Peoples R China Zhejiang Univ Microsatellite Res Ctr Hangzhou 310027 Peoples R China

Linearization error of the simplified linear electrical capacitance tomography (ECT) model is one of the leading causes of ECT reconstruction errors. In this paper, the least squares support vector regression (LSSVR) is used to fit the correlation between the capacitance vector and the linearization error. And it is trained by the training samples of typical phase distributions. When removing the linearization error from equations derived by the linear model, the reconstruction problem becomes an exact linear inverse problem because the nonlinearity of ECT is completely included in the linearization error. Then a reconstruction algorithm combining the LSSVR and the Landweber iteration is proposed. Numerical results show that the proposed algorithm achieves significantly better reconstruction accuracies than the linear back projection and the Landweber algorithm for both the noise free and noisy cases. Compared with the Landweber algorithm, The image errors of the reconstructions are reduced by about 23%-68%, and the correlation coefficient increased by about 0.04-0.14. And the calculation time of the proposed algorithm for all the tested cases is about 0.4-0.6s, which makes it have the potential for real-time imaging. Static experimental results show that the reconstructions of the proposed algorithm have more accurate phase boundary shapes and fewer artifacts.

关键词： ECT Least squares support vector regression Linearization error Nonlinear inverse problem reconstruction algorithm

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Evaluation of Backpropagation reconstruction algorithm for 3D Microwave Imaging of Body Part Anomalies

Evaluation of Backpropagation Reconstruction Algorithm for 3...

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IEEE International Symposium on Antennas and Propagation (IEEE AP-S) / IEEE USNC-CNC-URSI Radio Science Meeting

作者： Migliaccio, Claire Pichot, Christian Platt, Ian Tan, Adrian Woodhead, Ian Univ Cote Azur CNRS LEAT F-06903 Sophia Antipolis France Lincoln Agritech Ltd Canterbury New Zealand

We investigate the performance of a fast reconstruction algorithm based a Backpropagation algorithm for 3D Microwave Imaging of Body Part Anomalies.

ISBN: (纸本)9781728166704

We investigate the performance of a fast reconstruction algorithm based a Backpropagation algorithm for 3D Microwave Imaging of Body Part Anomalies.

关键词： microwave imaging biomedical electromagnetic imaging diffraction backpropagation reconstruction algorithm

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Optimized Filtered Back-Projection Tomographic reconstruction algorithm for the Step-Shift Scanning of a Sample

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RESEARCH IN NONDESTRUCTIVE EVALUATION 2019年第3期30卷 179-187页

作者： Ozdiev, Ali Hosenovich Afornu, Bright Kwame Sednev, Dmitry Andreevich Tomsk Polytech Univ Sch Nondestruct Testing & Secur Tomsk Russia

The variety of modern X-ray sources opens possibilities to conduct measurements of a wide range of different specimens. The range includes objects with various properties such as the density, the amount and types of defects, and the size which can significantly change from sample to sample. Due to the development of portable high energy X-ray sources like betatrons, it is now possible to investigate objects of big sizes. Although, the fact that the dimensions of such objects can exceed the dimensions of X-ray setups requires to develop new types of scanning geometries and to adopt the algorithms of reconstruction and visualization. The scanning of an object along its longest dimension is one of the ways for investigating such objects. In this article, we present the step-shift scanning approach and the adaptation of filtered back-projection algorithm for this type of measurement. The developed algorithm allows to obtain the visualization of the whole volume of the object from the combination of all scanning steps or to visualize the separate parts of the object from the truncated dataset.

关键词： X-Ray tomography non-destructive testing reconstruction algorithm scanning approach

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reconstruction algorithm FOR OBTAINING THE BENDING DEFORMATION OF THE BASE OF HEAVY-DUTY MACHINE TOOL USING INVERSE FINITE ELEMENT METHOD

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METROLOGY AND MEASUREMENT SYSTEMS 2018年第4期25卷 727-741页

作者： Liu, Mingyao Zhang, Xiong Song, Han Wang, Jingliang Zhou, Shiguang Wuhan Univ Technol Sch Mech & Elect Engn Wuhan 430070 Hubei Peoples R China Hubei Digital Mfg Key Lab Wuhan 430070 Hubei Peoples R China

The field of mechanical manufacturing is becoming more and more demanding on machining accuracy. It is essential to monitor and compensate the deformation of structural parts of a heavy-duty machine tool. The deformation of the base of a heavy-duty machine tool is an important factor that affects machining accuracy. The base is statically indeterminate and complex in load. It is difficult to reconstruct deformation by traditional methods. A reconstruction algorithm for determining bending deformation of the base of a heavy-duty machine tool using inverse Finite Element Method (iFEM) is presented. The base is equivalent to a multi-span beam which is divided into beam elements with support points as nodes. The deflection polynomial order of each element is analysed. According to the boundary conditions, the deformation compatibility conditions and the strain data measured by Fiber Bragg Grating (FBG), the deflection polynomial coefficients of a beam element are determined. Using the coordinate transformation, the deflection equation of the base is obtained. Both numerical verification and experiment were carried out. The deflection obtained by the reconstruction algorithm using iFEM and the actual deflection measured by laser displacement sensors were compared. The accuracy of the reconstruction algorithm is verified.

关键词： inverse Finite Element Method bending deformation heavy-duty machine tool reconstruction algorithm statically indeterminate structure

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Effects of acquisition method and reconstruction algorithm for CT number measurement on standard-dose CT and reduced-dose CT: a QIBA phantom study

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JAPANESE JOURNAL OF RADIOLOGY 2019年第5期37卷 399-411页

作者： Ohno, Yoshiharu Fujisawa, Yasuko Fujii, Kenji Sugihara, Naoki Kishida, Yuji Seki, Shinichiro Yoshikawa, Takeshi Kobe Univ Grad Sch Med Dept Radiol Div Funct & Diagnost Imaging ResChuo Ku 7-5-2 Kusunoki Cho Kobe Hyogo 6500017 Japan Kobe Univ Grad Sch Med Adv Biomed Imaging Res Ctr Kobe Hyogo Japan Canon Med Syst Corp Otawara Tochigi Japan Kobe Univ Grad Sch Med Dept Radiol Div Radiol Kobe Hyogo Japan

PurposeTo compare the effect of different acquisition and reconstruction methods on the radiation dose and accuracy of CT number measurements, using a 320-detector row CT and a Quantitative Imaging Biomarker Alliance (QIBA) recommended *** and methodsAcquisitions were performed on a 320-detector row CT, as 64- and 80-detector row helical and wide detector step-and-shoot (i.e., wide volume) acquisitions with tube currents of 400mA, 100mA, 50mA, 20mA, and 10mA. Image was reconstructed with the filtered back projection (FBP), adaptive iterative dose reduction using 3D processing (AIDR 3D), and forward projected model-based iterative reconstruction (FIRST) methods. The difference between measured CT numbers and the actual -856HU value of the phantom insert was determined by each CT acquisition protocol. Differences in actual and measured CT numbers were compared among acquisitions and among reconstruction methods by means of Tukey's HSD *** CT number obtained with 64-detector row helical acquisition was significantly larger than that obtained with others (p<0.0001). At each tube current, the CT number reconstructed with FIRST was significantly smaller than that with others (p<0.0001).ConclusionAcquisition and reconstruction methods are significantly affecting radiation dose reduction and accuracy of CT number measurements on a phantom study.

关键词： Lung CT Radiation dose reconstruction algorithm Scanning method

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