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  Subjects -> ENGINEERING (Total: 1962 journals)
    - CHEMICAL ENGINEERING (151 journals)
    - CIVIL ENGINEERING (149 journals)
    - ELECTRICAL ENGINEERING (82 journals)
    - ENGINEERING (1119 journals)
    - ENGINEERING MECHANICS AND MATERIALS (290 journals)
    - HYDRAULIC ENGINEERING (45 journals)
    - INDUSTRIAL ENGINEERING (52 journals)
    - MECHANICAL ENGINEERING (74 journals)

ENGINEERING (1119 journals)            First | 3 4 5 6 7 8 9 10 | Last

Journal of Applied Science and Technology     Full-text available via subscription  
Journal of Applied Sciences     Open Access   (Followers: 5)
Journal of Architectural Engineering     Full-text available via subscription   (Followers: 5)
Journal of ASTM International     Full-text available via subscription   (Followers: 3)
Journal of Aviation Technology and Engineering     Open Access   (Followers: 6)
Journal of Biological Dynamics     Open Access   (Followers: 1)
Journal of Biomedical Science     Open Access   (Followers: 2)
Journal of Biomolecular NMR     Hybrid Journal   (Followers: 3)
Journal of Biosciences     Open Access  
Journal of Catalysis     Hybrid Journal   (Followers: 5)
Journal of Central South University     Hybrid Journal  
Journal of China Universities of Posts and Telecommunications     Full-text available via subscription   (Followers: 2)
Journal of China University of Mining and Technology     Full-text available via subscription  
Journal of Cleaner Production     Hybrid Journal   (Followers: 10)
Journal of Coal Science and Engineering (China)     Hybrid Journal  
Journal of Cold Regions Engineering     Full-text available via subscription   (Followers: 3)
Journal of Combinatorial Designs     Hybrid Journal   (Followers: 2)
Journal of Combustion     Open Access   (Followers: 5)
Journal of Communications     Open Access   (Followers: 17)
Journal of Computational and Nonlinear Dynamics     Full-text available via subscription   (Followers: 4)
Journal of Computational and Theoretical Nanoscience     Full-text available via subscription   (Followers: 1)
Journal of Computational Biology     Hybrid Journal   (Followers: 6)
Journal of Computational Electronics     Hybrid Journal   (Followers: 1)
Journal of Computing and Information Science in Engineering     Full-text available via subscription   (Followers: 2)
Journal of Dairy Science     Hybrid Journal   (Followers: 13)
Journal of Display Technology     Hybrid Journal   (Followers: 2)
Journal of Dynamic Systems, Measurement, and Control     Full-text available via subscription   (Followers: 7)
Journal of Dynamical and Control Systems     Hybrid Journal   (Followers: 3)
Journal of Earthquake Engineering     Hybrid Journal   (Followers: 6)
Journal of Elasticity     Hybrid Journal   (Followers: 2)
Journal of Electroceramics     Hybrid Journal  
Journal of Electromagnetic Waves and Applications     Hybrid Journal   (Followers: 1)
Journal of Electronic Imaging     Partially Free   (Followers: 2)
Journal of Electronic Testing     Hybrid Journal   (Followers: 1)
Journal of Electronics Cooling and Thermal Control     Open Access   (Followers: 1)
Journal of Electrostatics     Hybrid Journal  
Journal of Energy Engineering     Full-text available via subscription   (Followers: 6)
Journal of Energy Resources Technology     Full-text available via subscription   (Followers: 5)
Journal of Engineering     Open Access  
Journal of Engineering and Computer Innovations     Open Access  
Journal of Engineering and Technology     Open Access   (Followers: 5)
Journal of Engineering and Technology Research     Open Access  
Journal of Engineering Design     Hybrid Journal   (Followers: 13)
Journal of Engineering Education     Hybrid Journal  
Journal of Engineering Entrepreneurship, The     Full-text available via subscription   (Followers: 3)
Journal of Engineering for Gas Turbines and Power     Full-text available via subscription   (Followers: 9)
Journal of Engineering Mathematics     Hybrid Journal  
Journal of Engineering Mechanics     Full-text available via subscription   (Followers: 12)
Journal of Engineering Physics and Thermophysics     Hybrid Journal  
Journal of Engineering Thermophysics     Hybrid Journal  
Journal of Engineering, Computers and Applied Sciences     Open Access  
Journal of Engineering, Design and Technology     Hybrid Journal   (Followers: 13)
Journal of Environmental & Engineering Geophysics     Full-text available via subscription  
Journal of Environmental Engineering     Full-text available via subscription   (Followers: 23)
Journal of Environmental Engineering and Landscape Management     Hybrid Journal   (Followers: 7)
Journal of Experimental Nanoscience     Hybrid Journal   (Followers: 3)
Journal of Fire Sciences     Hybrid Journal   (Followers: 1)
Journal of Flood Risk Management     Hybrid Journal   (Followers: 7)
Journal of Fluids Engineering     Full-text available via subscription   (Followers: 12)
Journal of Fourier Analysis and Applications     Hybrid Journal  
Journal of Fuel Cell Science and Technology     Full-text available via subscription   (Followers: 2)
Journal of Functional Analysis     Full-text available via subscription   (Followers: 1)
Journal of Fundamental and Applied Sciences     Open Access  
Journal of Geological Research     Open Access   (Followers: 1)
Journal of Geotechnical and Geoenvironmental Engineering     Full-text available via subscription   (Followers: 14)
Journal of Global Optimization     Hybrid Journal   (Followers: 4)
Journal of Guidance, Control, and Dynamics     Full-text available via subscription   (Followers: 49)
Journal of Healthcare Engineering     Full-text available via subscription   (Followers: 2)
Journal of Heat Transfer     Full-text available via subscription   (Followers: 22)
Journal of Humanitarian Engineering     Open Access   (Followers: 1)
Journal of Hydraulic Engineering     Full-text available via subscription   (Followers: 14)
Journal of Hyperspectral Remote Sensing     Open Access  
Journal of Imaging Science and Technology     Full-text available via subscription  
Journal of Industrial and Production Engineering     Hybrid Journal   (Followers: 2)
Journal of Industrial Engineering and Management     Open Access   (Followers: 4)
Journal of Inequalities and Applications     Open Access  
Journal of Infrared, Millimeter and Terahertz Waves     Hybrid Journal   (Followers: 1)
Journal of Integrated Design and Process Science     Hybrid Journal   (Followers: 1)
Journal of Intelligent and Fuzzy Systems     Hybrid Journal   (Followers: 9)
Journal of Inverse and Ill-posed Problems     Full-text available via subscription   (Followers: 1)
Journal of Irrigation and Drainage Engineering     Full-text available via subscription   (Followers: 10)
Journal of K-Theory     Full-text available via subscription  
Journal of King Saud University - Engineering Sciences     Open Access  
Journal of Konbin     Open Access  
Journal of Liquid Chromatography & Related Technologies     Hybrid Journal   (Followers: 8)
Journal of Management in Engineering     Full-text available via subscription   (Followers: 10)
Journal of Manufacturing Science and Engineering     Full-text available via subscription   (Followers: 10)
Journal of Manufacturing Systems     Full-text available via subscription   (Followers: 8)
Journal of Manufacturing Technology Management     Hybrid Journal   (Followers: 5)
Journal of Mathematical Modelling and Algorithms     Hybrid Journal   (Followers: 1)
Journal of Metallurgy     Open Access   (Followers: 1)
Journal of Middle European Construction and Design of Cars     Open Access   (Followers: 1)
Journal of Molecular Catalysis B: Enzymatic     Hybrid Journal  
Journal of Motor Behavior     Hybrid Journal   (Followers: 5)
Journal of Multivariate Analysis     Hybrid Journal   (Followers: 4)
Journal of Nanoengineering and Nanomanufacturing     Full-text available via subscription   (Followers: 1)
Journal of Nanoparticle Research     Hybrid Journal   (Followers: 3)
Journal of Nanoscience     Open Access  
Journal of Nanoscience and Nanotechnology     Full-text available via subscription   (Followers: 11)
Journal of NanoScience, NanoEngineering & Applications     Full-text available via subscription  

  First | 3 4 5 6 7 8 9 10 | Last

Journal of X-Ray Science and Technology
   Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0895-3996 - ISSN (Online) 1095-9114
     Published by IOS Press Homepage  [93 journals]   [SJR: 0.41]   [H-I: 20]
  • Integration of 3D scale-based pseudo-enhancement correction and partial
           volume image segmentation for improving electronic colon cleansing in CT
           colonograpy
    • Abstract: Orally administered tagging agents are usually used in CT colonography (CTC) to differentiate residual bowel content from native colonic structures. However, the high-density contrast agents tend to introduce pseudo-enhancement (PE) effect on neighboring soft tissues and elevate their observed CT attenuation value toward that of the tagged materials (TMs), which may result in an excessive electronic colon cleansing (ECC) since the pseudo-enhanced soft tissues are incorrectly identified as TMs. To address this issue, we integrated a 3D scale-based PE correction into our previous ECC pipeline based on the maximum a posteriori expectation-maximization partial volume (PV) segmentation. The newly proposed ECC scheme takes into account both the PE and PV effects that commonly appear in CTC images. We evaluated the new scheme on 40 patient CTC scans, both qualitatively through display of segmentation results, and quantitatively through radiologists' blind scoring (human observer) and computer-aided detection (CAD) of colon polyps (computer observer). Performance of the presented algorithm has shown consistent improvements over our previous ECC pipeline, especially for the detection of small polyps submerged in the contrast agents. The CAD results of polyp detection showed that 4 more submerged polyps were detected for our new ECC scheme over the previous one.
      Content Type Journal Article
      Pages 271-283

      DOI 10.3233/XST-140424

      Authors
      Hao Zhang, Department of Radiology, State University of New York at Stony Brook, Stony Brook, NY, USA
      Lihong Li, Department of Engineering Science and Physics, City University of New York at College of Staten Island, Staten Island, NY, USA
      Hongbin Zhu, Department of Radiology, State University of New York at Stony Brook, Stony Brook, NY, USA
      Hao Han, Department of Radiology, State University of New York at Stony Brook, Stony Brook, NY, USA
      Bowen Song, Department of Radiology, State University of New York at Stony Brook, Stony Brook, NY, USA
      Zhengrong Liang, Department of Radiology, State University of New York at Stony Brook, Stony Brook, NY, USA
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 2 / 2014
      PubDate: Thu, 03 Apr 2014 15:43:13 GMT
       
  • Removing streak artifacts from ECG-gated reconstructions using
           deconvolution
    • Abstract: BACKGROUND: 4D cardiac computed tomography aims at reconstructing the beating heart from a series of 2D projections and the simultaneously acquired electrocardiogram. Each cardiac phase is reconstructed by exploiting the subset of projections acquired during this particular cardiac phase only. In these conditions, the Feldkamp, Davis and Kress method (FDK) generates large streak artifacts in the reconstructed volumes, hampering the medical interpretation. These artifacts can be substantially reduced by deconvolution methods.OBJECTIVE: The aim of this paper is to compare two 4D cardiac CT reconstruction methods based on deconvolution, and to evaluate their practical benefits on two applications: cardiac micro CT and human cardiac C-arm CT.METHODS: The first evaluated method builds upon inverse filtering. It has been proposed recently and demonstrated on 4D cardiac micro CT. The second one is an iterative deconvolution method, and turns out equivalent to an ECG-gated Iterative Filtered Back Projection (ECG-gated IFBP).RESULTS: Results are presented on simulated data in 2D parallel beam, 2D fan beam and 3D cone beam geometries.CONCLUSIONS: Both methods are efficient on the cardiac micro CT simulations, but insufficient to handle 4D human cardiac C-Arm CT simulations. Overall, ECG-gated IFPB largely outperforms the inverse filtering method.
      Content Type Journal Article
      Pages 253-270

      DOI 10.3233/XST-140423

      Authors
      Cyril Mory, Université de Lyon, CREATIS, INSA-Lyon, Université Lyon 1, Villeurbanne Cedex, France
      Vincent Auvray, Philips Research Medisys, Suresnes, France
      Bo Zhang, Philips Research Medisys, Suresnes, France
      Michael Grass, Philips Research, Röntgenstrasse, Hamburg, Germany
      Dirk Schäfer, Philips Research, Röntgenstrasse, Hamburg, Germany
      Simon Rit, Université de Lyon, CREATIS, Lyon, France
      Françoise Peyrin, Université de Lyon, CREATIS, INSA-Lyon, Université Lyon 1, Villeurbanne Cedex, France
      Philippe Douek, Université de Lyon, CREATIS, INSA-Lyon, Université Lyon 1, Hospices Civils de Lyon, Lyon, France
      Loïc Boussel, Université de Lyon, CREATIS, INSA-Lyon, Université Lyon 1, Hospices Civils de Lyon, Lyon, France
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 2 / 2014
      PubDate: Thu, 03 Apr 2014 15:42:39 GMT
       
  • Multi-energy image sequence fusion based on variable energy X-ray imaging
    • Abstract: For complicated structural components characterized by wide X-ray attenuation ranges, the conventional fixed-energy imaging mode cannot obtain all structural information using a single tube voltage. This limitation results in information shortage, because the effective thickness of components along the orientation of the X-ray penetration exceeds the limit of the dynamic range of the X-ray imaging system. To solve this problem, multi-energy image sequence fusion technology has been advanced. In this new method, the tube voltage is adjusted several times by matching the voltage and the effective thickness to obtain all the effective local information on an object. Then, the subset sequences in the multi-energy image sequence are extracted based on the recursive template, and that are fused to reconstruct the full projection information based on linear weighting. An accompanying experiment demonstrates that the new technology can extend the dynamic range of X-ray imaging and provide a complete representation of the internal structure of complicated structural components.
      Content Type Journal Article
      Pages 241-251

      DOI 10.3233/XST-140422

      Authors
      Bin Liu, National Key Laboratory for Electronic Measurement Technology, North University of China, Taiyuan, Shannxi, China
      Yan Han, National Key Laboratory for Electronic Measurement Technology, North University of China, Taiyuan, Shannxi, China
      Jinxiao Pan, National Key Laboratory for Electronic Measurement Technology, North University of China, Taiyuan, Shannxi, China
      Ping Chen, National Key Laboratory for Electronic Measurement Technology, North University of China, Taiyuan, Shannxi, China
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 2 / 2014
      PubDate: Thu, 03 Apr 2014 15:41:46 GMT
       
  • Iterative CT reconstruction via minimizing adaptively reweighted total
           variation
    • Abstract: BACKGROUND: Iterative reconstruction via total variation (TV) minimization has demonstrated great successes in accurate CT imaging from under-sampled projections. When projections are further reduced, over-smoothing artifacts appear in the current reconstruction especially around the structure boundaries.OBJECTIVE: We propose a practical algorithm to improve TV-minimization based CT reconstruction on very few projection data.METHOD: Based on the theory of compressed sensing, the L-0 norm approach is more desirable to further reduce the projection views. To overcome the computational difficulty of the non-convex optimization of the L-0 norm, we implement an adaptive weighting scheme to approximate the solution via a series of TV minimizations for practical use in CT reconstruction. The weight on TV is initialized as uniform ones, and is automatically changed based on the gradient of the reconstructed image from the previous iteration. The iteration stops when a small difference between the weighted TV values is observed on two consecutive reconstructed images.RESULTS: We evaluate the proposed algorithm on both a digital phantom and a physical phantom. Using 20 equiangular projections, our method reduces reconstruction errors in the conventional TV minimization by a factor of more than 5, with improved spatial resolution.CONCLUSIONS: By adaptively reweighting TV in iterative CT reconstruction, we successfully further reduce the projection number for the same or better image quality.
      Content Type Journal Article
      Pages 227-240

      DOI 10.3233/XST-140421

      Authors
      Lei Zhu, Nuclear and Radiological Engineering and Medical Physics Programs, The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
      Tianye Niu, Nuclear and Radiological Engineering and Medical Physics Programs, The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
      Michael Petrongolo, Nuclear and Radiological Engineering and Medical Physics Programs, The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 2 / 2014
      PubDate: Thu, 03 Apr 2014 15:41:46 GMT
       
  • Simulation analysis of airflow alteration in the trachea following the
           vascular ring surgery based on CT images using the computational fluid
           dynamics method
    • Abstract: This study presents a computational fluid dynamics (CFD) model to simulate the three-dimensional airflow in the trachea before and after the vascular ring surgery (VRS). The simulation was based on CT-scan images of the patients with the vascular ring diseases. The surface geometry of the tracheal airway was reconstructed using triangular mesh by the Amira software package. The unstructured tetrahedral volume meshes were generated by the ANSYS ICEM CFD software package. The airflow in the tracheal airway was solved by the ESI CFD-ACE+ software package. Numerical simulation shows that the pressure drops across the tracheal stenosis before and after the surgery were 0.1789 and 0.0967 Pa, respectively, with the inspiratory inlet velocity 0.1 m/s. Meanwhile, the improvement percentage by the surgery was 45.95%. In the expiratory phase, by contrast, the improvement percentage was 40.65%. When the inspiratory velocity reached 1 m/s, the pressure drop became 4.988~Pa and the improvement percentage was 43.32%. Simulation results further show that after treatment the pressure drop in the tracheal airway was significantly decreased, especially for low inspiratory and expiratory velocities. The CFD method can be applied to quantify the airway pressure alteration and to evaluate the treatment outcome of the vascular ring surgery under different respiratory velocities.
      Content Type Journal Article
      Pages 213-225

      DOI 10.3233/XST-140420

      Authors
      Fong-Lin Chen, Institute of Medicine, Chung Shang Medical University, Taichung, Taiwan
      Tzyy-Leng Horng, Department of Applied Mathematics, Feng Chia University, Taichung, Taiwan
      Tzu-Ching Shih, Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 2 / 2014
      PubDate: Thu, 03 Apr 2014 15:41:09 GMT
       
  • The convergence of block cyclic projection with underrelaxation parameters
           for compressed sensing based tomography
    • Abstract: The block cyclic projection method in the compressed sensing framework (BCPCS) was introduced for image reconstruction in computed tomography and its convergence had been proven in the case of unity relaxation (λ=1). In this paper, we prove its convergence with underrelaxation parameters λ∈(0,1). As a result, the convergence of compressed sensing based block component averaging algorithm (BCAVCS) and block diagonally-relaxed orthogonal projection algorithm (BDROPCS) with underrelaxation parameters under a certain condition are derived. Experiments are given to illustrate the convergence behavior of these algorithms with selected parameters.
      Content Type Journal Article
      Pages 197-211

      DOI 10.3233/XST-140419

      Authors
      Fangjun Arroyo, Department of Mathematics, Francis Marion University, Florence, SC, USA
      Edward Arroyo, School of Science Technology, American Public University System, Manassas, VA, USA
      Xiezhang Li, Department of Mathematical Sciences, Georgia Southern University, Statesboro, GA, USA
      Jiehua Zhu, Department of Mathematical Sciences, Georgia Southern University, Statesboro, GA, USA
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 2 / 2014
      PubDate: Thu, 03 Apr 2014 15:40:59 GMT
       
  • Flexible methods for segmentation evaluation: Results from CT-based
           luggage screening
    • Abstract: BACKGROUND: Imaging systems used in aviation security include segmentation algorithms in an automatic threat recognition pipeline. The segmentation algorithms evolve in response to emerging threats and changing performance requirements. Analysis of segmentation algorithms' behavior, including the nature of errors and feature recovery, facilitates their development. However, evaluation methods from the literature provide limited characterization of the segmentation algorithms. OBJECTIVE: To develop segmentation evaluation methods that measure systematic errors such as oversegmentation and undersegmentation, outliers, and overall errors. The methods must measure feature recovery and allow us to prioritize segments. METHODS: We developed two complementary evaluation methods using statistical techniques and information theory. We also created a semi-automatic method to define ground truth from 3D images. We applied our methods to evaluate five segmentation algorithms developed for CT luggage screening. We validated our methods with synthetic problems and an observer evaluation.RESULTS: Both methods selected the same best segmentation algorithm. Human evaluation confirmed the findings. The measurement of systematic errors and prioritization helped in understanding the behavior of each segmentation algorithm.CONCLUSIONS: Our evaluation methods allow us to measure and explain the accuracy of segmentation algorithms.
      Content Type Journal Article
      Pages 175-195

      DOI 10.3233/XST-140418

      Authors
      Seemeen Karimi, University of California, San Diego, CA, USA
      Xiaoqian Jiang, University of California, San Diego, CA, USA
      Pamela Cosman, University of California, San Diego, CA, USA
      Harry Martz, Lawrence Livermore National Laboratories, Livermore, CA, USA
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 2 / 2014
      PubDate: Thu, 03 Apr 2014 15:40:59 GMT
       
  • Modulation of β-adrenergic receptor in rat lung after gamma
           irradiation
    • Abstract: OBJECTIVES: To study the effect of γ irradiation on β-adrenergic receptors of the lung.MATERIALS AND METHODS: Healthy Sprague-Dawley rats were used as an animal model. Cell membrane proteins of lung tissue were harvested after the whole lung received 20 Gy of ^{60}Co γ irradiation. ^{125}I-labeled iodopindolol (^{125}I-IPIN) was used as a ligand of β-adrenergic receptors. The numbers of the β-adrenergic receptors were determined by radioligand-receptor binding assay (RBA). Data were compared with irreversible blockage using antagonist bromoacetylalprenololmenthan (BAAM).RESULTS: The post-radiation RBA assay showed that the number of β-adrenergic receptors in lung tissue decreased at a steady rate. It decreased to 48% of the normal level at the 15th day after irradiation. At 40 days after radiation the level of β-adrenergic receptors started to increase at a steady rate and reached to the normal level around 70 days after radiation. There were significant differences in receptor synthesis, degradation and regeneration rates between irradiation group and BAMM group. CONCLUSIONS: The whole lung irradiation could severely affect the levels of β-adrenergic receptors. The potential clinical implications of radiation-induced changes of β-adrenergic receptors warrant further investigation.
      Content Type Journal Article
      Pages 165-173

      DOI 10.3233/XST-140417

      Authors
      Yong-Gang Qiang, Department of Experimental Nuclear Medicine, Guangzhou Medical University, Guangzhou, Guangdong, China
      Yong-Hua Liao, Department of Experimental Nuclear Medicine, Guangzhou Medical University, Guangzhou, Guangdong, China
      Xiu-Ping Zhang, Department of Radiation Oncology, Guangzhou Medical University, Guangzhou, Guangdong, China
      Jian Li, Department of Radiation Oncology, Guangzhou Medical University, Guangzhou, Guangdong, China
      Zheng Huang, School of Photonics and Electronic Engineering, Fujian Normal University, Fuzhou, Fujian, China
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 2 / 2014
      PubDate: Thu, 03 Apr 2014 15:40:22 GMT
       
  • A tensor PRISM algorithm for multi-energy CT reconstruction and
           comparative studies
    • Abstract: Different from the single-energy CT (SECT), multi-energy CT (MECT) acquires projection data at different energy spectra, which makes that the MECT has more sparsity among the data of separate energy and over energy. In order to maximize utilization of all these sparse characteristics, this paper proposed a new tensor PRISM model to consistently treat a priori knowledge of the low rank, intensity and sparsity with the higher-dimensional tensor technique. The priori knowledge of low rank corresponds to the stationary background and similarity over the energy, and the intensity and sparsity represents the rest of image features at single energy. Then, the regularization and convex minimization problem was solved by tensor unfolding and an extended tensor-based split-Bregman algorithm. Different from the previous PRISM algorithm, the new algorithm mixed and treated different constraints consistently. Numerical experiments have shown that our tensor PRISM approach performs much better than the popular l_{1} regularization algorithm in terms of image quality for MECT.
      Content Type Journal Article
      Pages 147-163

      DOI 10.3233/XST-140416

      Authors
      Liang Li, Department of Engineering Physics, Tsinghua University, Beijing, China
      Zhiqiang Chen, Department of Engineering Physics, Tsinghua University, Beijing, China
      Ge Wang, Biomedical Imaging Cluster, CBIS/BME, Rensselaer Polytechnic Institute, New York, NY, USA
      Jiyang Chu, Department of Engineering Physics, Tsinghua University, Beijing, China
      Hao Gao, Department of Mathematics, University of California, Los Angeles, CA, USA
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 2 / 2014
      PubDate: Thu, 03 Apr 2014 15:40:22 GMT
       
  • A new algorithm for calculating optimal viewing angles in coronary
           angiography based on 4-D cardiac computed tomography
    • Abstract: BACKGROUND: Coronary stenosis is the main cause of the coronary heart disease (CHD). However, coronary arteriography (CAG), which is considered as the 'gold standard' of determining the location and severity of CHD, hardly acquires a satisfactory image for some lesions by traditional viewing angles.OBJECTIVE: We proposed a new approach to calculate the optimal viewing angles of CAG system to observe vessel segment of interest.METHODS: Firstly, the 4-D coronary arteries are segmented to obtain a dynamic vessel model. Then, a "rendering" method in computer graphics is used to calculate the optimal viewing angles of the vessel segment in the entire cardiac cycle. At last, an intersection of these angles can be regarded as the optimal ones in the whole cardiac cycle.RESULTS: Within the constraint of 2% foreshortening, the single phase data show 1% foreshortening without overlapping at the optimal angles proposed by our method, compared with 1.8% foreshortening at working angles set by clinical experts. And the multi-phase experiments also have good results.CONCLUSIONS: The new approach can provide doctors optimal viewing angles of interested vessel segment in the whole cardiac cycle.
      Content Type Journal Article
      Pages 137-145

      DOI 10.3233/XST-140415

      Authors
      Xiaodong Chen, College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin, China
      Junwei Li, College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin, China
      Zhaoxia Zhang, College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin, China
      Yi Wang, College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin, China
      Zhongwei Jia, Department of Cardiovascular Medicine, People's Liberation Army 254 Hospital, Tianjin, China
      Kui Pu, Department of Cardiovascular Medicine, People's Liberation Army 254 Hospital, Tianjin, China
      Daoyin Yu, College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin, China
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 2 / 2014
      PubDate: Thu, 03 Apr 2014 15:39:02 GMT
       
  • The effect of detector size and energy resolution on image quality in
           multi-projection Compton scatter tomography
    • Abstract: The reconstructed electron density image quality is sensitive to the detector size and energy resolution, which contribute to the blurring and noise in the image. This work evaluates optimal values of the detector parameters for a realistic system through analytical simulations of the transverse slice of the dedicated breast CT system geometry. This study introduces a spectroscopic x-ray tomography technique which uses multiple projections to reconstruct electron density images by backprojecting scattered photons over isogonic curves. The reconstruction can be obtained using a single projection yet its quality degrades as the acquisition conditions i.e. detector size and energy resolution deviate from the ideal. The reconstruction quality becomes inconsistent throughout the image due to the data under sampling caused by the finite resolution of the detector. The extension to the multi-projection mode effectively fills-in the missing data space and improves the ability to reconstruct an object. This work demonstrates the possibility to obtain images in the presence of noise.
      Content Type Journal Article
      Pages 113-128

      DOI 10.3233/XST-130413

      Authors
      Tamar Chighvinadze, Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB, Canada
      Stephen Pistorius, Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB, Canada
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 1 / 2014
      PubDate: Tue, 21 Jan 2014 17:26:51 GMT
       
  • Ventricular hemodynamics using cardiac computed tomography and optical
           flow method
    • Abstract: Ventricular hemodynamics plays an important role in assessing cardiac function in clinical practice. The aim of this study was to determine the ventricular hemodynamics based on contrast movement in the left ventricle (LV) between the phases in a cardiac cycle recorded using an electrocardiography (ECG) with cardiac computed tomography (CT) and optical flow method. Cardiac CT data were acquired at 120 kV and 280 mA with a 350 ms gantry rotation, which covered one cardiac cycle, on the 640-slice CT scanner with ECG for a selected patient without heart disease. Ventricular hemodynamics (mm/phase) were calculated using the optical flow method based on contrast changes with ECG phases in anterior-posterior, lateral and superior-inferior directions. Local hemodynamic information of the LV with color coating was presented. The visualization of the functional information made the hemodynamic observation easy.
      Content Type Journal Article
      Pages 129-136

      DOI 10.3233/XST-130414

      Authors
      Yang-Hsien Lin, Department of Diagnostic Radiology, Peng Hu Hospital, Ministry of Health and Welfare, Taiwan
      Yung-Hui Huang, Department of Medical Imaging and Radiological Sciences, I-Shou University, Taiwan
      Kang-Ping Lin, Department of Electrical Engineering, Chung Yuan Christian University, Taiwan
      Juhn-Cherng Liu, Department of Radiology, China Medical University Hospital, Taiwan
      Tzung-Chi Huang, Department of Biomedical Imaging and Radiological Science, China Medical University, Taiwan
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 1 / 2014
      PubDate: Tue, 21 Jan 2014 17:26:51 GMT
       
  • Coherent soft X-ray high-order harmonics using tight-focusing laser pulses
           in the gas mixture
    • Abstract: We experimentally study the harmonics from a Xe-He gas mixture using tight-focusing femtosecond laser pulses. The spectrum in the mixed gases exhibits an extended cutoff region from the harmonic H21 to H27. The potential explanation is that the harmonics photons from Xe contribute the electrons of He atoms to transmit into the excited-state. Therefore, the harmonics are emitted from He atoms easily. Furthermore, we show that there are the suppressed harmonics H15 and H17 in the mixed gases. The underlying mechanism is the destructive interference between harmonics generated from different atoms. Our results indicate that HHG from Xe-He gas mixture is an efficient method of obtaining the coherent soft X-ray source.
      Content Type Journal Article
      Pages 105-111

      DOI 10.3233/XST-130412

      Authors
      Faming Lu, National Key Laboratory of Science and Technology on Tunable Laser, Institute of Opto-Electronics, Harbin Institute of Technology, Harbin, Heilongjiang, China
      Yuanqin Xia, National Key Laboratory of Science and Technology on Tunable Laser, Institute of Opto-Electronics, Harbin Institute of Technology, Harbin, Heilongjiang, China
      Sheng Zhang, National Key Laboratory of Science and Technology on Tunable Laser, Institute of Opto-Electronics, Harbin Institute of Technology, Harbin, Heilongjiang, China
      Deying Chen, National Key Laboratory of Science and Technology on Tunable Laser, Institute of Opto-Electronics, Harbin Institute of Technology, Harbin, Heilongjiang, China
      Yang Zhao, National Key Laboratory of Science and Technology on Tunable Laser, Institute of Opto-Electronics, Harbin Institute of Technology, Harbin, Heilongjiang, China
      Bin Liu, National Key Laboratory of Science and Technology on Tunable Laser, Institute of Opto-Electronics, Harbin Institute of Technology, Harbin, Heilongjiang, China
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 1 / 2014
      PubDate: Tue, 21 Jan 2014 17:26:18 GMT
       
  • Optimizing contrast agents with respect to reducing beam hardening in
           nonmedical X-ray computed tomography experiments
    • Abstract: Iodine is commonly used as a contrast agent in nonmedical science and engineering, for example, to visualize Darcy flow in porous geological media using X-ray computed tomography (CT). Undesirable beam hardening artifacts occur when a polychromatic X-ray source is used, which makes the quantitative analysis of CT images difficult. To optimize the chemistry of a contrast agent in terms of the beam hardening reduction, we performed computer simulations and generated synthetic CT images of a homogeneous cylindrical sand-pack (diameter, 28 or 56 mm; porosity, 39 vol.% saturated with aqueous suspensions of heavy elements assuming the use of a polychromatic medical CT scanner. The degree of cupping derived from the beam hardening was assessed using the reconstructed CT images to find the chemistry of the suspension that induced the least cupping. The results showed that (i) the degree of cupping depended on the position of the K absorption edge of the heavy element relative to peak of the polychromatic incident X-ray spectrum, (ii) _{53}I was not an ideal contrast agent because it causes marked cupping, and (iii) a single element much heavier than _{53}I (_{64}Gd to _{79}Au) reduced the cupping artifact significantly, and a four-heavy-element mixture of elements from _{64}Gd to _{79}Au reduced the artifact most significantly.
      Content Type Journal Article
      Pages 91-103

      DOI 10.3233/XST-130411

      Authors
      Yoshito Nakashima, National Institute of Advanced Industrial Science and Technology, Geological Survey of Japan, Tsukuba, Ibaraki, Japan
      Tsukasa Nakano, National Institute of Advanced Industrial Science and Technology, Geological Survey of Japan, Tsukuba, Ibaraki, Japan
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 1 / 2014
      PubDate: Tue, 21 Jan 2014 17:25:58 GMT
       
  • Adaptive zooming in X-ray computed tomography
    • Abstract: BACKGROUND: In computed tomography (CT), the source-detector system commonly rotates around the object in a circular trajectory. Such a trajectory does not allow to exploit a detector fully when scanning elongated objects. OBJECTIVE: Increase the spatial resolution of the reconstructed image by optimal zooming during scanning. METHODS: A new approach is proposed, in which the full width of the detector is exploited for every projection angle. This approach is based on the use of prior information about the object's convex hull to move the source as close as possible to the object, while avoiding truncation of the projections. RESULTS: Experiments show that the proposed approach can significantly improve reconstruction quality, producing reconstructions with smaller errors and revealing more details in the object. CONCLUSIONS: The proposed approach can lead to more accurate reconstructions and increased spatial resolution in the object compared to the conventional circular trajectory.
      Content Type Journal Article
      Pages 77-89

      DOI 10.3233/XST-130410

      Authors
      Andrei Dabravolski, iMinds-Vision Lab, University of Antwerp, Antwerpen, Belgium
      Kees Joost Batenburg, iMinds-Vision Lab, University of Antwerp, Antwerpen, Belgium
      Jan Sijbers, iMinds-Vision Lab, University of Antwerp, Antwerpen, Belgium
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 1 / 2014
      PubDate: Tue, 21 Jan 2014 17:25:46 GMT
       
  • X-ray strain tensor imaging: FEM simulation and experiments with a
           micro-CT
    • Abstract: In tissue elasticity imaging, measuring the strain tensor components is necessary to solve the inverse problem. However, it is impractical to measure all the tensor components in ultrasound or MRI elastography because of their anisotropic spatial resolution. The objective of this study is to compute 3D strain tensor maps from the 3D CT images of a tissue-mimicking phantom. We took 3D micro-CT images of the phantom twice with applying two different mechanical compressions to it. Applying the 3D image correlation technique to the CT images under different compression, we computed 3D displacement vectors and strain tensors at every pixel. To evaluate the accuracy of the strain tensor maps, we made a 3D FEM model of the phantom, and we computed strain tensor maps through FEM simulation. Experimentally obtained strain tensor maps showed similar patterns to the FEM-simulated ones in visual inspection. The correlation between the strain tensor maps obtained from the experiment and the FEM simulation ranges from 0.03 to 0.93. Even though the strain tensor maps suffer from high level noise, we expect the x-ray strain tensor imaging may find some biomedical applications such as malignant tissue characterization and stress analysis inside the tissues.
      Content Type Journal Article
      Pages 63-75

      DOI 10.3233/XST-130409

      Authors
      Jae G. Kim, Department of Biomedical Engineering, Kyung Hee University, Yongin-si, Korea
      So E. Park, Department of Biomedical Engineering, Kyung Hee University, Yongin-si, Korea
      Soo Y. Lee, Department of Biomedical Engineering, Kyung Hee University, Yongin-si, Korea
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 1 / 2014
      PubDate: Tue, 21 Jan 2014 17:25:36 GMT
       
  • EDART, a discrete algebraic reconstructing technique for experimental data
           obtained with high resolution computed tomography
    • Abstract: A novel reconstruction method is presented to improve the image quality of three dimensional (3D) datasets for samples consisting of only one material and surrounding air, obtained with high resolution X-ray Computed Tomography (μCT). It combines discrete tomography with iterative reconstruction algorithms, it is applicable for routine μCT applications and is referred to as the Experimental Discrete Algebraic Reconstruction Technique (EDART). A fast and intuitive method to estimate the attenuation coefficient and segmentation threshold, in case these are unknown, is included. Experimental results illustrate that EDART allows the improvement of the reconstruction quality as compared to standard iterative reconstruction when few projections are available, without significantly increasing the reconstruction time.
      Content Type Journal Article
      Pages 47-61

      DOI 10.3233/XST-130408

      Authors
      L. Brabant, Department of Physics and Astronomy, Ghent University, Gent, Belgium
      M. Dierick, Department of Physics and Astronomy, Ghent University, Gent, Belgium
      E. Pauwels, Department of Physics and Astronomy, Ghent University, Gent, Belgium
      M.N. Boone, Department of Physics and Astronomy, Ghent University, Gent, Belgium
      L. Van Hoorebeke, Department of Physics and Astronomy, Ghent University, Gent, Belgium
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 1 / 2014
      PubDate: Tue, 21 Jan 2014 17:25:26 GMT
       
  • Interior reconstruction method based on rotation-translation scanning
           model
    • Abstract: In various applications of computed tomography (CT), it is common that the reconstructed object is over the field of view (FOV) or we may intend to sue a FOV which only covers the region of interest (ROI) for the sake of reducing radiation dose. These kinds of imaging situations often lead to interior reconstruction problems which are difficult cases in the reconstruction field of CT, due to the truncated projection data at every view angle. In this paper, an interior reconstruction method is developed based on a rotation-translation (RT) scanning model. The method is implemented by first scanning the reconstructed region, and then scanning a small region outside the support of the reconstructed object after translating the rotation centre. The differentiated backprojection (DBP) images of the reconstruction region and the small region outside the object can be respectively obtained from the two-time scanning data without data rebinning process. At last, the projection onto convex sets (POCS) algorithm is applied to reconstruct the interior region. Numerical simulations are conducted to validate the proposed reconstruction method.
      Content Type Journal Article
      Pages 37-45

      DOI 10.3233/XST-130407

      Authors
      Xianchao Wang, Air Force Early Warning Academy, Wuhan, Hubei, China
      Ziyue Tang, Air Force Early Warning Academy, Wuhan, Hubei, China
      Bin Yan, National Digital Switching System Engineering and Technological Research Center, Zhengzhou, Henan, China
      Lei Li, National Digital Switching System Engineering and Technological Research Center, Zhengzhou, Henan, China
      Shanglian Bao, The Beijing City Key Lab of Medical Physics and Engineering, Peking University, Beijing, China
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 1 / 2014
      PubDate: Tue, 21 Jan 2014 17:24:56 GMT
       
  • Practical geometric calibration for helical cone-beam industrial computed
           tomography
    • Abstract: In helical cone-beam industrial computed tomography (ICT), the reconstructed images may be interfered by geometry artifacts due to the presence of mechanical misalignments. To obtain artifact-free reconstruction images, a practical geometric calibration method for helical scan is investigated based on Noo's analytic geometric calibration method for circular scan. The presented method is implemented by first dividing the whole ascending path of helical scan into several pieces, then acquiring the projections of a dedicated calibration phantom in circular scan at each section point, of which geometry parameters are calculated using Noo's analytic method. At last, the geometry parameters of each projection in a piece can be calculated by those of the two end points of the piece. We performed numerical simulations and real data experiments to study the performance of the presented method. The experimental results indicated that the method can obtain high-precision geometry parameters of helical scan and give satisfactory reconstruction images.
      Content Type Journal Article
      Pages 19-35

      DOI 10.3233/XST-130406

      Authors
      Feng Zhang, National Digital Switching System Engineering and Technology Research Center, Zhengzhou, Henan, China
      Bin Yan, National Digital Switching System Engineering and Technology Research Center, Zhengzhou, Henan, China
      Lei Li, National Digital Switching System Engineering and Technology Research Center, Zhengzhou, Henan, China
      Xiaoqi Xi, National Digital Switching System Engineering and Technology Research Center, Zhengzhou, Henan, China
      Hua Jiang, National Digital Switching System Engineering and Technology Research Center, Zhengzhou, Henan, China
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 1 / 2014
      PubDate: Tue, 21 Jan 2014 17:24:55 GMT
       
  • An improved distance-driven method for projection and backprojection
    • Abstract: Fast and accurate image reconstruction is the ultimate goal of iterative methods for limited-angle, few-view, interior problems, etc. Recently, a finite-detector-based projection model was proposed for iterative CT reconstructions, which was called area integral model (AIM) and has shown a high spatial resolution but with a high computational complexity. On the other hand, the distance-driven model (DDM) is the state-of-the-art technology to model forward projection and backprojection, which has shown a low computational complexity but relative low spatial resolution than AIM-based method. Inspired by the DDM, here we propose an improved distance-driven model (IDDM), which has a similar computational complexity with the DDM-based method and comparative spatial resolution with the AIM-based method. In an ordered-subset simultaneous algebraic reconstruction technique (OS-SART) framework, the AIM, IDDM and DDM are implemented and evaluated using a sinogram from a phantom experiment on a Discovery CT750 HD scanner. The results show that the computational cost of DDM- and IDDM-based methods is similar, which is 6 to 13~times faster than the AIM-based method assuming the same number of iterations. The spatial resolution of AIM- and IDDM-based method is comparable, which is better than DDM-based method in terms of full-width-of-half-maximum (FWHM).
      Content Type Journal Article
      Pages 1-18

      DOI 10.3233/XST-130405

      Authors
      Chuang Miao, Biomedical Imaging Division, VT-WFU School of Biomedical Engineering and Sciences, Wake Forest University, Winston-Salem, NC, USA
      Baodong Liu, Biomedical Imaging Division, VT-WFU School of Biomedical Engineering and Sciences, Wake Forest University, Winston-Salem, NC, USA
      Qiong Xu, Institute of Image Processing and Pattern Recognition, Xi'an Jiaotong University, Xi'an, Shaanxi, China
      Hengyong Yu, Biomedical Imaging Division, VT-WFU School of Biomedical Engineering and Sciences, Wake Forest University, Winston-Salem, NC, USA
      Journal Journal of X-Ray Science and Technology
      Online ISSN 1095-9114
      Print ISSN 0895-3996
      Journal Volume Volume 22
      Journal Issue Volume 22, Number 1 / 2014
      PubDate: Tue, 21 Jan 2014 17:24:53 GMT
       
 
 
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