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Sample records for 2-d imaging diagnostics

  1. A 2-D ECE Imaging Diagnostic for TEXTOR

    Wang, J.; Deng, B. H.; Domier, C. W.; Luhmann, H. Lu, Jr.

    2002-11-01

    A true 2-D extension to the UC Davis ECE Imaging (ECEI) concept is under development for installation on the TEXTOR tokamak in 2003. This combines the use of linear arrays with multichannel conventional wideband heterodyne ECE radiometers to provide a true 2-D imaging system. This is in contrast to current 1-D ECEI systems in which 2-D images are obtained through the use of multiple plasma discharges (varying the scanned emission frequency each discharge). Here, each array element of the 20 channel mixer array measures plasma emission at 16 simultaneous frequencies to form a 16x20 image of the plasma electron temperature Te. Correlation techniques can then be applied to any pair of the 320 image elements to study both radial and poloidal characteristics of turbulent Te fluctuations. The system relies strongly on the development of low cost, wideband (2-18 GHz) IF detection electronics for use in both ECE Imaging as well as conventional heterodyne ECE radiometry. System details, with a strong focus on the wideband IF electronics development, will be presented. *Supported by U.S. DoE Contracts DE-FG03-95ER54295 and DE-FG03-99ER54531.

  2. Diesel combustion and emissions formation using multiple 2-D imaging diagnostics

    Dec, J.E. [Sandia National Labs., Livermore, CA (United States)

    1997-12-31

    Understanding how emissions are formed during diesel combustion is central to developing new engines that can comply with increasingly stringent emission standards while maintaining or improving performance levels. Laser-based planar imaging diagnostics are uniquely capable of providing the temporally and spatially resolved information required for this understanding. Using an optically accessible research engine, a variety of two-dimensional (2-D) imaging diagnostics have been applied to investigators of direct-injection (DI) diesel combustion and emissions formation. These optical measurements have included the following laser-sheet imaging data: Mie scattering to determine liquid-phase fuel distributions, Rayleigh scattering for quantitative vapor-phase-fuel/air mixture images, laser induced incandescence (LII) for relative soot concentrations, simultaneous LII and Rayleigh scattering for relative soot particle-size distributions, planar laser-induced fluorescence (PLIF) to obtain early PAH (polyaromatic hydrocarbon) distributions, PLIF images of the OH radical that show the diffusion flame structure, and PLIF images of the NO radical showing the onset of NO{sub x} production. In addition, natural-emission chemiluminescence images were obtained to investigate autoignition. The experimental setup is described, and the image data showing the most relevant results are presented. Then the conceptual model of diesel combustion is summarized in a series of idealized schematics depicting the temporal and spatial evolution of a reacting diesel fuel jet during the time period investigated. Finally, recent PLIF images of the NO distribution are presented and shown to support the timing and location of NO formation hypothesized from the conceptual model.

  3. Process to generate a synthetic diagnostic for microwave imaging reflectometry with the full-wave code FWR2D.

    Ren, X; Domier, C W; Kramer, G; Luhmann, N C; Muscatello, C M; Shi, L; Tobias, B J; Valeo, E

    2014-11-01

    A synthetic microwave imaging reflectometer (MIR) diagnostic employing the full-wave reflectometer code (FWR2D) has been developed and is currently being used to guide the design of real systems, such as the one recently installed on DIII-D. The FWR2D code utilizes real plasma profiles as input, and it is combined with optical simulation tools for synthetic diagnostic signal generation. A detailed discussion of FWR2D and the process to generate the synthetic signal are presented in this paper. The synthetic signal is also compared to a prescribed density fluctuation spectrum to quantify the imaging quality. An example is presented with H-mode-like plasma profiles derived from a DIII-D discharge, where the MIR focal is located in the pedestal region. It is shown that MIR is suitable for diagnosing fluctuations with poloidal wavenumber up to 2.0 cm(-1) and fluctuation amplitudes less than 5%. PMID:25430276

  4. Precise 2D-imaging color filter spectrograph with wedged optical filters in femtosecond systems diagnostics

    Divoký, Martin; Straka, Petr

    Arcachon: N, 2009, 246-247. ISBN N. [UltraFast Optics ( UFO VII) and High Field Short Wavelength (HFSW XIII) meetings. Arcachon (FR), 31.08.2009-04.09.2009] R&D Projects: GA MŠk(CZ) LC528 Grant ostatní: EC - LASERLAB-EUROPE(XE) RII3-CT-2003-506350 Institutional research plan: CEZ:AV0Z10100523 Keywords : imaging spectrograph * angular dispersion * spatial dispersion Subject RIV: BH - Optics, Masers, Lasers

  5. A synthetic diagnostic to modelled expected 2-D radiation power loss profile for the infrared imaging video bolometer of the Aditya tokamak

    A 'synthetic diagnostic' has been developed to theoretically estimate the radiation from the ADITYA tokamak plasma using Infrared Imaging Video Bolometer (IRVB). These theoretical results will then be compared with the results obtained experimentally. The IRVB is a two dimensional (2-D) plasma radiation imaging diagnostic IRVB is used to measure time resolved 2-D profile of radiation power loss with wide field of view (FOV). The synthetic IRVB assumes symmetry in the tokamak. In poloidal cross-section it assumes symmetric parabolic profiles of plasma temperature, plasma density and impurity density. The IRVB system is essentially a pinhole camera system. It traces the line of sights of each bolometer pixel through the plasma volume and calculates local power emissivity at each volume element in space using the radiative cooling rates of plasma impurity. Finally line integrated emissivity 2-D profile provides a brightness profile at each bolometer pixel. This brightness profile is the expected IRVB image at foil location By considering the system etendue the power loss profile can be computed. Using the synthetic diagnostic, spatial response of the experimental diagnostic, FOV, expected signal level and Signal to Noise ratio can be determined. The synthetic IRVB used to simulate ADITYA-IRVB diagnostic and results were compared with experimental results. (author)

  6. Design and implementation of gas puff imaging diagnostic to investigate 2D turbulence in the plasma of the COMPASS tokamak

    Cavalier, Jordan; Weinzettl, Vladimír; Varju, Jozef; Pánek, Radomír

    Prague: Czech Technical University in Prague, Faculty of Electrical Engineering, 2014. s. 21. [SPPT 2014 - 26th Symposium on Plasma Physics and Technology/26./. 16.06.2014-19.06.2014, Prague] Keywords : Tokamak edge plasma * gas-puff imaging * diagnostic Subject RIV: BL - Plasma and Gas Discharge Physics

  7. Diagnostic Imaging

    Diagnostic imaging lets doctors look inside your body for clues about a medical condition. A variety of machines and ... and activities inside your body. The type of imaging your doctor uses depends on your symptoms and ...

  8. Automatic Contour Extraction from 2D Image

    Panagiotis GIOANNIS

    2011-03-01

    Full Text Available Aim: To develop a method for automatic contour extraction from a 2D image. Material and Method: The method is divided in two basic parts where the user initially chooses the starting point and the threshold. Finally the method is applied to computed tomography of bone images. Results: An interesting method is developed which can lead to a successful boundary extraction of 2D images. Specifically data extracted from a computed tomography images can be used for 2D bone reconstruction. Conclusions: We believe that such an algorithm or part of it can be applied on several other applications for shape feature extraction in medical image analysis and generally at computer graphics.

  9. 2D electron cyclotron emission imaging at ASDEX Upgrade (invited)

    Classen, I. G. J. [Max Planck Institut fuer Plasmaphysik, 85748 Garching (Germany); FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Boom, J. E.; Vries, P. C. de [FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Suttrop, W.; Schmid, E.; Garcia-Munoz, M.; Schneider, P. A. [Max Planck Institut fuer Plasmaphysik, 85748 Garching (Germany); Tobias, B.; Domier, C. W.; Luhmann, N. C. Jr. [University of California at Davis, Davis, California 95616 (United States); Donne, A. J. H. [FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Jaspers, R. J. E. [Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Park, H. K. [POSTECH, Pohang, Gyeongbuk, 790-784 (Korea, Republic of); Munsat, T. [University of Colorado, Boulder, Colorado 80309 (United States)

    2010-10-15

    The newly installed electron cyclotron emission imaging diagnostic on ASDEX Upgrade provides measurements of the 2D electron temperature dynamics with high spatial and temporal resolution. An overview of the technical and experimental properties of the system is presented. These properties are illustrated by the measurements of the edge localized mode and the reversed shear Alfven eigenmode, showing both the advantage of having a two-dimensional (2D) measurement, as well as some of the limitations of electron cyclotron emission measurements. Furthermore, the application of singular value decomposition as a powerful tool for analyzing and filtering 2D data is presented.

  10. 2D microwave imaging reflectometer electronics.

    Spear, A G; Domier, C W; Hu, X; Muscatello, C M; Ren, X; Tobias, B J; Luhmann, N C

    2014-11-01

    A 2D microwave imaging reflectometer system has been developed to visualize electron density fluctuations on the DIII-D tokamak. Simultaneously illuminated at four probe frequencies, large aperture optics image reflections from four density-dependent cutoff surfaces in the plasma over an extended region of the DIII-D plasma. Localized density fluctuations in the vicinity of the plasma cutoff surfaces modulate the plasma reflections, yielding a 2D image of electron density fluctuations. Details are presented of the receiver down conversion electronics that generate the in-phase (I) and quadrature (Q) reflectometer signals from which 2D density fluctuation data are obtained. Also presented are details on the control system and backplane used to manage the electronics as well as an introduction to the computer based control program. PMID:25430247

  11. 2D microwave imaging reflectometer electronics

    Spear, A. G.; Domier, C. W., E-mail: cwdomier@ucdavis.edu; Hu, X.; Muscatello, C. M.; Ren, X.; Luhmann, N. C. [Electrical and Computer Engineering, University of California, Davis, California 95616 (United States); Tobias, B. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2014-11-15

    A 2D microwave imaging reflectometer system has been developed to visualize electron density fluctuations on the DIII-D tokamak. Simultaneously illuminated at four probe frequencies, large aperture optics image reflections from four density-dependent cutoff surfaces in the plasma over an extended region of the DIII-D plasma. Localized density fluctuations in the vicinity of the plasma cutoff surfaces modulate the plasma reflections, yielding a 2D image of electron density fluctuations. Details are presented of the receiver down conversion electronics that generate the in-phase (I) and quadrature (Q) reflectometer signals from which 2D density fluctuation data are obtained. Also presented are details on the control system and backplane used to manage the electronics as well as an introduction to the computer based control program.

  12. Imaging Techniques for Microwave Diagnostics

    Tobias, B.; Donne, A. J. H.; Park, H. K.; Boom, J. E.; Choi, M. J.; Classen, I.G.J.; Domier, C.W.; Kong, X.; Lee, W.; Liang, T.; N C Luhmann Jr.,; Munsat, T.; Yu, L.; Yun, G. S.

    2011-01-01

    Imaging diagnostics, such as Electron Cyclotron Emission Imaging (ECEI) and Microwave Imaging Reflectometry (MIR), exhibit unique characteristics that make them particularly well suited to the validation of theoretical models for plasma instabilities and turbulent fluctuations. A 2-D picture of plas

  13. Upgrade of 2-D antenna array for microwave imaging reflectometry and ECE imaging

    Two types of 2-D Microwave Imaging, Microwave Imaging Reflectometry (MIR) and Electron Cyclotron Emission Imaging (ECEI) have been developed for the Large Helical Device (LHD). These are methods of 2-D / 3-D imaging diagnostics on electron density fluctuations and electron temperature for the investigation of micro-turbulence and magneto-hydrodynamic instabilities in magnetically confined plasmas. 1-D horn antenna array was developed for a 2-D receiver antenna array of the MIR (freq. range: 50 - 75 GHz). This antenna is also able to be used for a receiver of the ECEI (freq. range: 95 - 110 GHz). To apply the ECEI receiver, and to extend the measurement range of these diagnostics, the 1-D horn antenna array was upgraded. (author)

  14. Textbook of diagnostic imaging

    Three volumes provide information organized by major topics covering the state-of-the-art for all imaging procedures. It includes coverage of the fundamentals of diagnostic imaging, and a system-by-system approach

  15. 2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas

    Thomas, D.A.; Brunner, K.J.; Freethy, S.J.; Huang, B.K.; Shevchenko, V. F.; Vann, R. G. L.

    2016-01-01

    Doppler backscattering (DBS) is already established as a powerful diagnostic; its extension to 2D enables imaging of turbulence characteristics from an extended region of the cut-off surface. The Synthetic Aperture Microwave Imaging (SAMI) diagnostic has conducted proof-of-principle 2D DBS experiments of MAST edge plasma. SAMI actively probes the plasma edge using a wide (±40° vertical and horizontal) and tuneable (10–34.5 GHz) beam. The Doppler backscattered signal is digitised in vector for...

  16. Photorealistic image synthesis and camera validation from 2D images

    Santos Ferrer, Juan C.; González Chévere, David; Manian, Vidya

    2014-06-01

    This paper presents a new 3D scene reconstruction technique using the Unity 3D game engine. The method presented here allow us to reconstruct the shape of simple objects and more complex ones from multiple 2D images, including infrared and digital images from indoor scenes and only digital images from outdoor scenes and then add the reconstructed object to the simulated scene created in Unity 3D, these scenes are then validated with real world scenes. The method used different cameras settings and explores different properties in the reconstructions of the scenes including light, color, texture, shapes and different views. To achieve the highest possible resolution, it was necessary the extraction of partial textures from visible surfaces. To recover the 3D shapes and the depth of simple objects that can be represented by the geometric bodies, there geometric characteristics were used. To estimate the depth of more complex objects the triangulation method was used, for this the intrinsic and extrinsic parameters were calculated using geometric camera calibration. To implement the methods mentioned above the Matlab tool was used. The technique presented here also let's us to simulate small simple videos, by reconstructing a sequence of multiple scenes of the video separated by small margins of time. To measure the quality of the reconstructed images and video scenes the Fast Low Band Model (FLBM) metric from the Video Quality Measurement (VQM) software was used. Low bandwidth perception based features include edges and motion.

  17. 2-D Imaging of Electron Temperature in Tokamak Plasmas

    By taking advantage of recent developments in millimeter wave imaging technology, an Electron Cyclotron Emission Imaging (ECEI) instrument, capable of simultaneously measuring 128 channels of localized electron temperature over a 2-D map in the poloidal plane, has been developed for the TEXTOR tokamak. Data from the new instrument, detailing the MHD activity associated with a sawtooth crash, is presented

  18. 2-D Imaging of Electron Temperature in Tokamak Plasmas

    T. Munsat; E. Mazzucato; H. Park; C.W. Domier; M. Johnson; N.C. Luhmann Jr.; J. Wang; Z. Xia; I.G.J. Classen; A.J.H. Donne; M.J. van de Pol

    2004-07-08

    By taking advantage of recent developments in millimeter wave imaging technology, an Electron Cyclotron Emission Imaging (ECEI) instrument, capable of simultaneously measuring 128 channels of localized electron temperature over a 2-D map in the poloidal plane, has been developed for the TEXTOR tokamak. Data from the new instrument, detailing the MHD activity associated with a sawtooth crash, is presented.

  19. Diagnostic Imaging Workshop

    The American Association of Physicist in Medicine (AAPM), the International Organization for Medical Physics (IOMP) and the Argentina Society of Medical Physics (SAFIM) was organized the Diagnostic Imaging Workshop 2012, in the city of Buenos Aires, Argentina. This workshop was an oriented training and scientific exchange between professionals and technicians who work in medical physics, especially in the areas of diagnostic imaging, nuclear medicine and radiotherapy, with special emphasis on the use of multimodal imaging for radiation treatment, planning as well of quality assurance associates.

  20. 2-D Tissue Motion Compensation of Synthetic Transmit Aperture Images

    Gammelmark, Kim Løkke; Jensen, Jørgen Arendt

    2014-01-01

    Synthetic transmit aperture (STA) imaging is susceptible to tissue motion because it uses summation of low-resolution images to create the displayed high-resolution image. A method for 2-D tissue motion correction in STA imaging is presented. It utilizes the correlation between highresolution...... performed by tracking each pixel in the reconstructed image using the estimated velocity and direction. The method is evaluated using simulations, and phantom and in vivo experiments. In phantoms, a tissue velocity of 15 cm/s at a 45° angle was estimated with relative bias and standard deviation of −6...

  1. Topology-Preserving Rigid Transformation of 2D Digital Images.

    Ngo, Phuc; Passat, Nicolas; Kenmochi, Yukiko; Talbot, Hugues

    2014-02-01

    We provide conditions under which 2D digital images preserve their topological properties under rigid transformations. We consider the two most common digital topology models, namely dual adjacency and well-composedness. This paper leads to the proposal of optimal preprocessing strategies that ensure the topological invariance of images under arbitrary rigid transformations. These results and methods are proved to be valid for various kinds of images (binary, gray-level, label), thus providing generic and efficient tools, which can be used in particular in the context of image registration and warping. PMID:26270925

  2. Targeted fluorescence imaging enhanced by 2D materials: a comparison between 2D MoS2 and graphene oxide.

    Xie, Donghao; Ji, Ding-Kun; Zhang, Yue; Cao, Jun; Zheng, Hu; Liu, Lin; Zang, Yi; Li, Jia; Chen, Guo-Rong; James, Tony D; He, Xiao-Peng

    2016-08-01

    Here we demonstrate that 2D MoS2 can enhance the receptor-targeting and imaging ability of a fluorophore-labelled ligand. The 2D MoS2 has an enhanced working concentration range when compared with graphene oxide, resulting in the improved imaging of both cell and tissue samples. PMID:27378648

  3. Contributions to statistical image segmentation and 2D pattern Recognition

    Derrode, Stéphane

    2008-01-01

    This dissertation follows 9 years of my research activities, including 7 years as an assistant professor at the École Centrale Marseille and as a researcher into the Multidimensional Signal Processing Group of Institut Fresnel (CNRS UMR 6133). Works which I present explore some aspects of the statistical segmentation of images for applications in space imagery and the invariant description of 2D shapes for object recognition in video imagery. More precisely, the first part of the manuscript s...

  4. 2D imaging of functional structures in perfused pig heart

    Kessler, Manfred D.; Cristea, Paul D.; Hiller, Michael; Trinks, Tobias

    2002-06-01

    In 2000 by 2D-imaging we were able for the first time to visualize in subcellular space functional structures of myocardium. For these experiments we used hemoglobin-free perfused pig hearts in our lab. Step by step we learned to understand the meaning of subcellular structures. Principally, the experiment revealed that in subcellular space very fast changes of light scattering can occur. Furthermore, coefficients of different parameters were determined on the basis of multicomponent system theory.

  5. Development of 2-D antenna array for microwave imaging reflectometry in LHD

    A 2-D antenna array for the Microwave Imaging Reflectometry (MIR) has been developed for the Large Helical Device (LHD). The MIR is a method of electron density diagnostics by the use of microwave radar techniques to obtain 2-D/3-D images of electron density fluctuations for the investigation of micro-turbulence and magneto-hydrodynamic instabilities in magnetically confined plasmas. The antenna array consists of five antennas in the toroidal direction and eight ones in the poloidal direction, respectively. As a test of an antenna element, a pyramidal horn antenna in the frequency range of 10-15 GHz was compared with the Yagi-Uda antenna. Based on the test results of the lower frequency antenna element, we manufactured a 2-D horn antenna array in the frequency range of 50-75 GHz. (author)

  6. 2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas

    Thomas, D. A.; Brunner, K. J.; Freethy, S. J.; Huang, B. K.; Shevchenko, V. F.; Vann, R. G. L.

    2016-02-01

    Doppler backscattering (DBS) is already established as a powerful diagnostic; its extension to 2D enables imaging of turbulence characteristics from an extended region of the cut-off surface. The Synthetic Aperture Microwave Imaging (SAMI) diagnostic has conducted proof-of-principle 2D DBS experiments of MAST edge plasma. SAMI actively probes the plasma edge using a wide (±40° vertical and horizontal) and tuneable (10-34.5 GHz) beam. The Doppler backscattered signal is digitised in vector form using an array of eight Vivaldi PCB antennas. This allows the receiving array to be focused in any direction within the field of view simultaneously to an angular range of 6-24° FWHM at 10-34.5 GHz. This capability is unique to SAMI and is a novel way of conducting DBS experiments. In this paper the feasibility of conducting 2D DBS experiments is explored. Initial observations of phenomena previously measured by conventional DBS experiments are presented; such as momentum injection from neutral beams and an abrupt change in power and turbulence velocity coinciding with the onset of H-mode. In addition, being able to carry out 2D DBS imaging allows a measurement of magnetic pitch angle to be made; preliminary results are presented. Capabilities gained through steering a beam using a phased array and the limitations of this technique are discussed.

  7. A Volume Rendering Algorithm for Sequential 2D Medical Images

    吕忆松; 陈亚珠

    2002-01-01

    Volume rendering of 3D data sets composed of sequential 2D medical images has become an important branch in image processing and computer graphics.To help physicians fully understand deep-seated human organs and focuses(e.g.a tumour)as 3D structures.in this paper,we present a modified volume rendering algorithm to render volumetric data,Using this method.the projection images of structures of interest from different viewing directions can be obtained satisfactorily.By rotating the light source and the observer eyepoint,this method avoids rotates the whole volumetric data in main memory and thus reduces computational complexity and rendering time.Experiments on CT images suggest that the proposed method is useful and efficient for rendering 3D data sets.

  8. Iterative 2D deconvolution of portal imaging radiographs

    Portal imaging has become an integral part of modern radiotherapy techniques such as IMRT and IGRT. It serves to verify the accuracy of day-to-day patient positioning, a prerequisite for treatment success. However, image blurring attributable to different physical and geometrical effects, analysed in this work, impairs the image quality of the portal images, and anatomical structures cannot always be clearly outlined. A 2D iterative deconvolution method was developed to reduce this image blurring. The affiliated data basis was generated by the separate measurement of the components contributing to image blurring. Secondary electron transport and pixel size within the EPID, as well as geometrical penumbra due to the finite photon source size were found to be the major contributors, whereas photon scattering in the patient is less important. The underlying line-spread kernels of these components were shown to be Lorentz functions. This implies that each of these convolution kernels and also their combination can be characterized by a single characteristic, the width parameter λ of the Lorentz function. The overall resulting λ values were 0.5 mm for 6 MV and 0.65 mm for 15 MV. Portal images were deconvolved using the point-spread function derived from the Lorentz function together with the experimentally determined λ values. The improvement of the portal images was quantified in terms of the modulation transfer function of a bar pattern. The resulting clinical images show a clear enhancement of sharpness and contrast. (orig.)

  9. Symmetries of the 2D magnetic particle imaging system matrix

    In magnetic particle imaging (MPI), the relation between the particle distribution and the measurement signal can be described by a linear system of equations. For 1D imaging, it can be shown that the system matrix can be expressed as a product of a convolution matrix and a Chebyshev transformation matrix. For multidimensional imaging, the structure of the MPI system matrix is not yet fully explored as the sampling trajectory complicates the physical model. It has been experimentally found that the MPI system matrix rows have symmetries and look similar to the tensor products of Chebyshev polynomials. In this work we will mathematically prove that the 2D MPI system matrix has symmetries that can be used for matrix compression. (paper)

  10. 2D magnetic nanoparticle imaging using magnetization response second harmonic

    Tanaka, Saburo, E-mail: tanakas@ens.tut.ac.jp [Toyohashi University of Technology, 1-1 Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Murata, Hayaki; Oishi, Tomoya; Suzuki, Toshifumi [Toyohashi University of Technology, 1-1 Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Zhang, Yi [Peter Gruenberg Institute, Forschungszentrum Juelich, Juelich D-52425 (Germany)

    2015-06-01

    A detection method and an imaging technique for magnetic nanoparticles (MNPs) have been investigated. In MNP detection and in magnetic particle imaging (MPI), the most commonly employed method is the detection of the odd harmonics of the magnetization response. We examined the advantage of using the second harmonic response when applying an AC magnetic modulation field and a DC bias field. If the magnetization response is detected by a Cu-wound-coil detection system, the output voltage from the coil is proportional to the change in the flux, dϕ/dt. Thus, the dependence of the derivative of the magnetization, M, on an AC magnetic modulation field and a DC bias field were calculated and investigated. The calculations were in good agreement with the experimental results. We demonstrated that the use of the second harmonic response for the detection of MNPs has an advantage compared with the usage of the third harmonic response, when the Cu-wound-coil detection system is employed and the amplitude of the ratio of the AC modulation field and a knee field H{sub ac}/H{sub k} is less than 2. We also constructed a 2D MPI scanner using a pair of permanent ring magnets with a bore of ϕ80 mm separated by 90 mm. The magnets generated a gradient of G{sub z}=3.17 T/m transverse to the imaging bore and G{sub x}=1.33 T/m along the longitudinal axis. An original concentrated 10 μl Resovist solution in a ϕ2×3 mm{sup 2} vessel was used as a sample, and it was imaged by the scanner. As a result, a 2D contour map image could be successfully generated using the method with a lock-in amplifier.

  11. Non-rigid consistent registration of 2D image sequences

    We present a novel algorithm for the registration of 2D image sequences that combines the principles of multiresolution B-spline-based elastic registration and those of bidirectional consistent registration. In our method, consecutive triples of images are iteratively registered to gradually extend the information through the set of images of the entire sequence. The intermediate results are reused for the registration of the following triple. We choose to interpolate the images and model the deformation fields using B-spline multiresolution pyramids. Novel boundary conditions are introduced to better characterize the deformations at the boundaries. In the experimental section, we quantitatively show that our method recovers from barrel/pincushion and fish-eye deformations with subpixel error. Moreover, it is more robust against outliers-occasional strong noise and large rotations-than the state-of-the-art methods. Finally, we show that our method can be used to realign series of histological serial sections, which are often heavily distorted due to folding and tearing of the tissues.

  12. [Diagnostic imaging of lying].

    Lass, Piotr; Sławek, Jarosław; Sitek, Emilia; Szurowska, Edyta; Zimmermann, Agnieszka

    2013-01-01

    Functional diagnostic imaging has been applied in neuropsychology for more than two decades. Nowadays, the functional magnetic resonance (fMRI) seems to be the most important technique. Brain imaging in lying has been performed and discussed since 2001. There are postulates to use fMRI for forensic purposes, as well as commercially, e.g. testing the loyalty of employees, especially because of the limitations of traditional polygraph in some cases. In USA fMRI is performed in truthfulness/lying assessment by at least two commercial companies. Those applications are a matter of heated debate of practitioners, lawyers and specialists of ethics. The opponents of fMRI use for forensic purposes indicate the lack of common agreement on it and the lack of wide recognition and insufficient standardisation. Therefore it cannot serve as a forensic proof, yet. However, considering the development of MRI and a high failure rate of traditional polygraphy, forensic applications of MRI seem to be highly probable in future. PMID:23888745

  13. Moyamoya disease: Diagnostic imaging

    Moyamoya disease is a progressive vasculopathy leading to stenosis of the main intracranial arteries. The incidence of moyamoya disease is high in Asian countries; in Europe and North America, the prevalence of the disease is considerably lower. Clinically, the disease may be of ischaemic, haemorrhagic and epileptic type. Cognitive dysfunction and behavioral disturbance are atypical symptoms of moyamoya disease. Characteristic angiographic features of the disease include stenosis or occlusion of the arteries of the circle of Willis, as well as the development of collateral vasculature. Currently, magnetic resonance angiography and CT angiography with multi-row systems are the main imaging methods of diagnostics of the entire range of vascular changes in moyamoya disease. The most common surgical treatment combines the direct arterial anastomosis between the superficial temporal artery and middle cerebral, and the indirect synangiosis involving placement of vascularised tissue in the brain cortex, in order to promote neoangiogenesis. Due to progressive changes, correct and early diagnosis is of basic significance in selecting patients for surgery, which is the only effective treatment of the disease. An appropriate qualification to surgery should be based on a comprehensive angiographic and imaging evaluation of brain structures. Despite the rare occurrence of moyamoya disease in European population, it should be considered as one of causes of ischaemic or haemorrhagic strokes, especially in young patients

  14. Imaging diagnostics of the foot

    The book on imaging diagnostics of the foot contains the following chapters: (1) Imaging techniques. (2) Clinical diagnostics. (3) Ankle joint and hind foot. (4) Metatarsus. (5) Forefoot. (6) Pathology of plantar soft tissue. (7) Nervous system diseases. (8) Diseases without specific anatomic localization. (9) System diseases including the foot. (10) Tumor like lesions. (11) Normative variants.

  15. Filters in 2D and 3D Cardiac SPECT Image Processing

    Maria Lyra

    2014-01-01

    Full Text Available Nuclear cardiac imaging is a noninvasive, sensitive method providing information on cardiac structure and physiology. Single photon emission tomography (SPECT evaluates myocardial perfusion, viability, and function and is widely used in clinical routine. The quality of the tomographic image is a key for accurate diagnosis. Image filtering, a mathematical processing, compensates for loss of detail in an image while reducing image noise, and it can improve the image resolution and limit the degradation of the image. SPECT images are then reconstructed, either by filter back projection (FBP analytical technique or iteratively, by algebraic methods. The aim of this study is to review filters in cardiac 2D, 3D, and 4D SPECT applications and how these affect the image quality mirroring the diagnostic accuracy of SPECT images. Several filters, including the Hanning, Butterworth, and Parzen filters, were evaluated in combination with the two reconstruction methods as well as with a specified MatLab program. Results showed that for both 3D and 4D cardiac SPECT the Butterworth filter, for different critical frequencies and orders, produced the best results. Between the two reconstruction methods, the iterative one might be more appropriate for cardiac SPECT, since it improves lesion detectability due to the significant improvement of image contrast.

  16. Maximizing entropy of image models for 2-D constrained coding

    Forchhammer, Søren; Danieli, Matteo; Burini, Nino; Zamarin, Marco; Ukhanova, Ann

    2010-01-01

    This paper considers estimating and maximizing the entropy of two-dimensional (2-D) fields with application to 2-D constrained coding. We consider Markov random fields (MRF), which have a non-causal description, and the special case of Pickard random fields (PRF). The PRF are 2-D causal finite context models, which define stationary probability distributions on finite rectangles and thus allow for calculation of the entropy. We consider two binary constraints and revisit the hard square const...

  17. Maximizing entropy of image models for 2-D constrained coding

    Forchhammer, Søren; Danieli, Matteo; Burini, Nino;

    2010-01-01

    This paper considers estimating and maximizing the entropy of two-dimensional (2-D) fields with application to 2-D constrained coding. We consider Markov random fields (MRF), which have a non-causal description, and the special case of Pickard random fields (PRF). The PRF are 2-D causal finite...... of the Markov random field defined by the 2-D constraint is estimated to be (upper bounded by) 0.8570 bits/symbol using the iterative technique of Belief Propagation on 2 £ 2 finite lattices. Based on combinatorial bounding techniques the maximum entropy for the constraint was determined to be 0.848....

  18. Comparison of the accuracy and precision of prostate localization with 2D-2D and 3D images

    Logadottir, Ashildur; Korreman, Stine; Munck af Rosenschöld, Per

    2011-01-01

    Background and purpose Positional uncertainties related to the set-up of the prostate, using internal markers and either 2D–2D or 3D images, were studied. Set-up using direct prostate localization on CBCT scans is compared to set-up using internal markers. Material and methods 20 patients with...... prostate cancer were enrolled in the study. After each daily session, a set of 2D–2D and 3D images were acquired. The images isocenter was compared to reference images isocenter. For the set-up error analysis the systematic error, μ, and the set-up uncertainties, Σ and σ, were determined for the......, were comparable. The correlation between the two methods was better for translational shifts of the isocenter than for rotational shifts. Conclusions The study shows that the precision of the 2D–2D set-up is equivalent to the precision of the 3D images. It also shows that the soft-tissue based set...

  19. EDGE2D modelling of edge profiles obtained in JET diagnostic optimized configuration

    Kallenbach, A [MPI fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Andrew, Y [EURATOM/UKAEA Fusion Association, Culham (United Kingdom); Beurskens, M [FOM-Rijnhuizen, Ass. Euratom-FOM, TEC (Netherlands); Corrigan, G [EURATOM/UKAEA Fusion Association, Culham (United Kingdom); Eich, T [MPI fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Jachmich, S [ERM, Brussels (Belgium); Kempenaars, M [FOM-Rijnhuizen, Ass. Euratom-FOM, TEC (Netherlands); Korotkov, A [EURATOM/UKAEA Fusion Association, Culham (United Kingdom); Loarte, A [EFDA Close Support Unit, Garching (Germany); Matthews, G [EURATOM/UKAEA Fusion Association, Culham (United Kingdom); Monier-Garbet, P [CEA Cadarache (France); Saibene, G [EFDA Close Support Unit, Garching (Germany); Spence, J [EURATOM/UKAEA Fusion Association, Culham (United Kingdom); Suttrop, W [MPI fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)

    2004-03-01

    Nine type-I ELMy H-mode discharges in diagnostic optimized configuration in JET are analysed with the EDGE2D/NIMBUS package. EDGE2D solves the fluid equations for the conservation of particles, momentum and energy for hydrogenic and impurity ions, while neutrals are followed with the two-dimensional Monte Carlo module NIMBUS. Using external boundary conditions from the experiment, the perpendicular heat conductivities {chi}{sub i,e} and the particle transport coefficients D, v are varied until good agreement between code result and measured data is obtained. A step-like ansatz is used for the edge transport parameters for the outer core region, the edge transport barrier and the outer scrape-off layer. The time-dependent effect of edge localized modes on the edge profiles is simulated with an ad hoc ELM model based on the repetitive increase of the transport coefficients {chi}{sub i,e} and D. The values of the transport coefficients are matched to experimental data mapped to the outer midplane, in the course of which radial shifts of experimental profiles of the order of 1 cm caused by the accuracy limit of the equilibrium reconstruction are taken into account. Simulated divertor profiles obtained from the upstream transport ansatz and the experimental boundary conditions agree with measurements, except a small region localized at the separatrix strike points which is supposed to be affected by direct ion losses. The integrated analysis using EDGE2D modelling, although still limited by the marginal spatial resolution of individual diagnostics, allows the characterization of profiles in the edge/pedestal region and supplies additional information on the separatrix position. The steep density gradient zone inside the separatrix shrinks compared to the electron temperature with increasing density, indicating the effect of the neutral penetration depth becoming shorter than the region of reduced transport.

  20. Development of ultra-fast 2D ion Doppler tomography using image intensified CMOS fast camera

    Tanabe, Hiroshi; Kuwahata, Akihiro; Yamanaka, Haruki; Inomoto, Michiaki; Ono, Yasushi; TS-group Team

    2015-11-01

    The world fastest novel time-resolved 2D ion Doppler tomography diagnostics has been developed using fast camera with high-speed gated image intensifier (frame rate: 200kfps. phosphor decay time: ~ 1 μ s). Time evolution of line-integrated spectra are diffracted from a f=1m, F/8.3 and g=2400L/mm Czerny-Turner polychromator, whose output is intensified and recorded to a high-speed camera with spectral resolution of ~0.005nm/pixel. The system can accommodate up to 36 (9 ×4) spatial points recorded at 5 μs time resolution, tomographic reconstruction is applied for the line-integrated spectra, time-resolved (5 μs/frame) local 2D ion temperature measurement has been achieved without any assumption of shot repeatability. Ion heating during intermittent reconnection event which tends to happen during high guide field merging tokamak was measured around diffusion region in UTST. The measured 2D profile shows ion heating inside the acceleration channel of reconnection outflow jet, stagnation point and downstream region where reconnected field forms thick closed flux surface as in MAST. Achieved maximum ion temperature increases as a function of Brec2 and shows good fit with MAST experiment, demonstrating promising CS-less startup scenario for spherical tokamak. This work is supported by JSPS KAKENHI Grant Number 15H05750 and 15K20921.

  1. Performance evaluation of 2D image registration algorithms with the numeric image registration and comparison platform

    The objective of this work is to present the capabilities of the NUMERICS web platform for evaluation of the performance of image registration algorithms. The NUMERICS platform is a web accessible tool which provides access to dedicated numerical algorithms for registration and comparison of medical images (http://numerics.phys.uni-sofia.bg). The platform allows comparison of noisy medical images by means of different types of image comparison algorithms, which are based on statistical tests for outliers. The platform also allows 2D image registration with different techniques like Elastic Thin-Plate Spline registration, registration based on rigid transformations, affine transformations, as well as non-rigid image registration based on Mobius transformations. In this work we demonstrate how the platform can be used as a tool for evaluation of the quality of the image registration process. We demonstrate performance evaluation of a deformable image registration technique based on Mobius transformations. The transformations are applied with appropriate cost functions like: Mutual information, Correlation coefficient, Sum of Squared Differences. The accent is on the results provided by the platform to the user and their interpretation in the context of the performance evaluation of 2D image registration. The NUMERICS image registration and image comparison platform provides detailed statistical information about submitted image registration jobs and can be used to perform quantitative evaluation of the performance of different image registration techniques. (authors)

  2. High resolution 2D image upconversion of incoherent light

    Dam, Jeppe Seidelin; Pedersen, Christian; Tidemand-Lichtenberg, Peter

    2011-01-01

    An optimized method for continuous wave 2-dimensional (2-D) upconversion of incoherent or thermal light is demonstrated and quantified. Using standard resolution targets a resolution of 200×1000 pixels is obtained. The suggested method is viewed in scope of modern CCD cameras operating in the near...

  3. Volumetric Synthetic Aperture Imaging with a Piezoelectric 2-D Row-Column Probe

    Bouzari, Hamed; Engholm, Mathias; Christiansen, Thomas Lehrmann;

    2016-01-01

    The synthetic aperture (SA) technique can be used for achieving real-time volumetric ultrasound imaging using 2-D row-column addressed transducers. This paper investigates SA volumetric imaging performance of an in-house prototyped 3 MHz λ/2-pitch 62+62 element piezoelectric 2-D row-column addres......The synthetic aperture (SA) technique can be used for achieving real-time volumetric ultrasound imaging using 2-D row-column addressed transducers. This paper investigates SA volumetric imaging performance of an in-house prototyped 3 MHz λ/2-pitch 62+62 element piezoelectric 2-D row...

  4. Extending Ripley's K-Function to Quantify Aggregation in 2-D Grayscale Images.

    Mohamed Amgad

    Full Text Available In this work, we describe the extension of Ripley's K-function to allow for overlapping events at very high event densities. We show that problematic edge effects introduce significant bias to the function at very high densities and small radii, and propose a simple correction method that successfully restores the function's centralization. Using simulations of homogeneous Poisson distributions of events, as well as simulations of event clustering under different conditions, we investigate various aspects of the function, including its shape-dependence and correspondence between true cluster radius and radius at which the K-function is maximized. Furthermore, we validate the utility of the function in quantifying clustering in 2-D grayscale images using three modalities: (i Simulations of particle clustering; (ii Experimental co-expression of soluble and diffuse protein at varying ratios; (iii Quantifying chromatin clustering in the nuclei of wt and crwn1 crwn2 mutant Arabidopsis plant cells, using a previously-published image dataset. Overall, our work shows that Ripley's K-function is a valid abstract statistical measure whose utility extends beyond the quantification of clustering of non-overlapping events. Potential benefits of this work include the quantification of protein and chromatin aggregation in fluorescent microscopic images. Furthermore, this function has the potential to become one of various abstract texture descriptors that are utilized in computer-assisted diagnostics in anatomic pathology and diagnostic radiology.

  5. Imaging Techniques for Microwave Diagnostics

    Donne, T. [FOM-Institute for Plasma Physics Rijnhuizen, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Luhmann Jr, N.C. [University of California, Davis, CA 95616 (United States); Park, H.K. [POSTECH, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Tobias, B.

    2011-07-01

    Advances in microwave technology have made it possible to develop a new generation of microwave imaging diagnostics for measuring the parameters of magnetic fusion devices. The most prominent of these diagnostics is electron cyclotron emission imaging (ECE-I). After the first generation of ECE-I diagnostics utilized at the TEXT-U, RTP and TEXTOR tokamaks and the LHD stellarator, new systems have recently come into operation on ASDEX-UG and DIII-D, soon to be followed by a system on KSTAR. The DIII-D and KSTAR systems feature dual imaging arrays that observe different parts of the plasma. The ECE-I diagnostic yields two-dimensional movies of the electron temperature in the plasma and has given already new insights into the physics of sawtooth oscillations, tearing modes and edge localized modes. Microwave Imaging Reflectometry (MIR) is used on LHD to measure electron density fluctuations. A pilot MIR system has been tested at TEXTOR and, based on the promising results, a new system is now under design for KSTAR. The system at TEXTOR was used to measure the plasma rotation velocity. The system at KSTAR and also the one on LHD will be/are used for measuring the profile of the electron density fluctuations in the plasma. Other microwave imaging diagnostics are phase imaging interferometry, and imaging microwave scattering. The emphasis in this paper will be largely focused on ECE-I. First an overview of the advances in microwave technology are discussed, followed by a description of a typical ECE-I system along with some typical experimental results. Also the utilization of imaging techniques in other types of microwave diagnostics will be briefly reviewed. This document is composed of the slides of the presentation. (authors)

  6. Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging

    Simoens, F.; Meilhan, J.; Gidon, S.; Lasfargues, G.; Lalanne Dera, J.; Ouvrier-Buffet, J. L.; Pocas, S.; Rabaud, W.; Guellec, F.; Dupont, B.; Martin, S.; Simon, A. C.

    2013-09-01

    CEA-Leti has developed a monolithic large focal plane array bolometric technology optimized for 2D real-time imaging in the terahertz range. Each pixel consists in a silicon microbolometer coupled to specific antennas and a resonant quarter-wavelength cavity. First prototypes of imaging arrays have been designed and manufactured for optimized sensing in the 1-3.5THz range where THz quantum cascade lasers are delivering high optical power. NEP in the order of 1 pW/sqrt(Hz) has been assessed at 2.5 THz. This paper reports the steps of this development, starting from the pixel level, to an array associated monolithically to its CMOS ROIC and finally a stand-alone camera. For each step, modeling, technological prototyping and experimental characterizations are presented.

  7. Image Reconstruction from 2D stack of MRI/CT to 3D using Shapelets

    Arathi T

    2014-12-01

    Full Text Available Image reconstruction is an active research field, due to the increasing need for geometric 3D models in movie industry, games, virtual environments and in medical fields. 3D image reconstruction aims to arrive at the 3D model of an object, from its 2D images taken at different viewing angles. Medical images are multimodal, which includes MRI, CT scan image, PET and SPECT images. Of these, MRI and CT scan images of an organ when taken, is available as a stack of 2D images, taken at different angles. This 2D stack of images is used to get a 3D view of the organ of interest, to aid doctors in easier diagnosis. Existing 3D reconstruction techniques are voxel based techniques, which tries to reconstruct the 3D view based on the intensity value stored at each voxel location. These techniques don’t make use of the shape/depth information available in the 2D image stack. In this work, a 3D reconstruction technique for MRI/CT 2D image stack, based on Shapelets has been proposed. Here, the shape/depth information available in each 2D image in the image stack is manipulated to get a 3D reconstruction, which gives a more accurate 3D view of the organ of interest. Experimental results exhibit the efficiency of this proposed technique.

  8. 2D geometric measurement method based on industrial CT images

    To achieve the non-destructive measurement of the internal structure of the objects, a kind of automatic dimension measuring method using industrial computed tomography (ICT) images was presented based on a threshold of edge extraction. First, a pretreatment of CT images was carried out Then, the best threshold segmentation method was used to extract edge, based on this work the automatic geometry measurement of the CT images was achieved. The results show that geometric measurement of images reaches to a certain degree of accuracy and meet the basic needs of accuracy and repeatability. Simultaneously this method may reduce the influence of artifacts. (authors)

  9. Evaluation of the middle and inner ear structures: comparison of hybrid rendering, virtual endoscopy and axial 2D source images

    Recent developments in 3D reconstructions can enhance the quality and diagnostic value of axial 2D image data sets with direct benefits for clinical practice. To show the possible advantages of a hybrid rendering method [color-coded 3D shaded-surface display (SSD)- and volume rendering method] with the possibility of virtual endoscopy we have specifically highlighted the use in relation to the middle and inner ear structures. We examined 12 patients with both normal findings and postoperative changes, using image data sets from high-resolution spiral computed tomography (HRSCT). The middle and inner ear was segmented using an interactive threshold interval density volume-growing method and visualized with a color-coded SSD rendering method. The temporal bone was visualized using a transparent volume rendering method. The 3D- and virtual reconstructions were compared with the axial 2D source images. The evaluated middle and inner ear structures could be seen in their complete form and correct topographical relationship, and the 3D- and virtual reconstructions indicated an improved representation and spatial orientation of these structures. A hybrid and virtual endoscopic method could add information and improve the value of imaging in the diagnosis and management of patients with middle or inner ear diseases making the understanding and interpretation of axial 2D CT image data sets easier. The introduction of an improved rendering algorithm aids radiological diagnostics, medical education, surgical planning, surgical training, and postoperative assessment. (orig.)

  10. Image Reconstruction from 2D stack of MRI/CT to 3D using Shapelets

    Arathi T; Latha Parameswaran

    2014-01-01

    Image reconstruction is an active research field, due to the increasing need for geometric 3D models in movie industry, games, virtual environments and in medical fields. 3D image reconstruction aims to arrive at the 3D model of an object, from its 2D images taken at different viewing angles. Medical images are multimodal, which includes MRI, CT scan image, PET and SPECT images. Of these, MRI and CT scan images of an organ when taken, is available as a stack of 2D images, taken at different a...

  11. Fast 2-D 8×8 discrete cosine transform algorithm for image coding

    JI XiuHua; ZHANG CaiMing; WANG JiaYe; BOEY S. H.

    2009-01-01

    A new fast two-dimension 8×8 discrete cosine transform (2D 8×8 DCT) algorithm based on the charac-teristics of the basic images of 2D DCT is presented. The new algorithm computes each DCT coefficient in turn more independently. Hence, the new algorithm is suitable for 2D DCT pruning algorithm of prun-ing away any number of high-frequency components of 2D DCT. The proposed pruning algorithm ls more efficient than the existing pruning 2D DCT algorithms in terms of the number of arithmetic opera-tions, especially the number of multiplications required in the computation.

  12. Cerebrovascular diagnostics - Imaging

    Imaging of the cerebral vasculature relies mostly on computed tomography angiography (CTA), magnetic resonance angiography (MRA) and digital subtraction angiography (DSA). Although DSA is still the gold standard, many questions can be answered with CTA and/or MRA thanks to recent technological advances. The following article describes the advantages and disadvantages of these techniques with regard to different questions. Basic principles regarding the different techniques are explained. (orig.)

  13. Diagnostic imaging in COPD

    COPD is a heterogeneous disease defined by expiratory airflow limitation. Airflow limitation is caused by a variable combination of emphysematous destruction of lung parenchyma and small airway obstruction. Only advanced emphysema can be diagnosed by chest X-ray. Less severe emphysema and changes in small airways are commonly diagnosed by computed tomography. Typical visual appearance of pathologic changes in lung parenchyma and airways of COPD patients are presented, furthermore methods for quantitative assessment of these changes and the crucial role of imaging for surgical and bronchoscopic treatment in COPD are discussed. (orig.)

  14. Workload measurement: diagnostic imaging

    Departments of medical imaging, as with many other service departments in the health industry, are being asked to develop performance indicators. No longer are they assured that annual budget allocations will be forthcoming without justification or some output measurement indicators that will substantiate a claim for a reasonable share of resources. The human resource is the most valuable and the most expensive to any department. This paper provides a brief overview of the research and implementation of a radiographer workload measurement system that was commenced in the Brisbane North Health Region. 2 refs., 10 tabs

  15. Automatic guidance of robotized 2D ultrasound probes with visual servoing based on image moments.

    Mebarki, Rafik

    2010-01-01

    There is error in the front page of the first document (v1). This dissertation presents a new 2D ultrasound-based visual servoing method. The main goal is to automatically guide a robotized 2D ultrasound probe held by a medical robot in order to reach a desired cross-section ultrasound image of an object of interest. This method allows to control both the in-plane and out-of-plane motions of a 2D ultrasound probe. It makes direct use of the 2D ultrasound image in the visual servo scheme, w...

  16. MR cholangiopancreatography: prospective comparison of a breath-hold 2D projection technique with diagnostic ERCP

    Lomas, D.J.; Bearcroft, P.W.P.; Gimson, A.E. [University Department of Radiology, Addenbrooke Hospital, Cambridge (United Kingdom)

    1999-09-01

    The aim of this study was to compare prospectively a breath-hold projection magnetic resonance cholangiopancreatography (MRCP) technique with diagnostic endoscopic retrograde cholangiopancreatography (ERCP). Seventy-six patients with suspected strictures or choledocholithiasis were referred for MRCP and subsequent ERCP examination, which were performed within 4 h of each other. The MRCP technique was performed using fat-suppressed rapid acquisition with relaxation enhancement (RARE) projection images obtained in standardised planes with additional targeted projections as required by the supervising radiologist. Two radiologists (in consensus) assessed the MRCP results prospectively and independently for the presence of bile duct calculi, strictures, non-specific biliary dilatation and pancreatic duct dilatation, and recorded a single primary diagnosis. The ERCP was assessed prospectively and independently by a single endoscopist and used as a gold standard for comparison with MRCP. Diagnostic agreement was assessed by the Kappa statistic. The MRCP technique failed in two patients and ERCP in five. In the remaining 69 referrals ERCP demonstrated normal findings in 23 cases, strictures in 19 cases, choledocholithiasis in 9 cases, non-specific biliary dilatation in 14 cases and chronic pancreatitis in 4 cases. The MRCP technique correctly demonstrated 22 of 23 normal cases, 19 strictures with one false positive (sensitivity 100 %, specificity 98 %), all 9 cases of choledocholithiasis with two false positives (sensitivity 100 %, specificity 97 %), 12 of 14 cases of non-specific biliary dilatation and only 1 of 4 cases of chronic pancreatitis. There was overall good agreement for diagnosis based on a kappa value of 0.88. Breath-hold projection MRCP can provide non-invasively comparable diagnostic information to diagnostic ERCP for suspected choledocholithiasis and biliary strictures and may allow more selective use of therapeutic ERCP. (orig.) With 6 figs., 1 tab., 20

  17. Diagnostic imaging of exotic pets

    Radiographic, ultrasonographic, and computed tomographic (CT) imaging are important diagnostic modalities in exotic pets. The use of appropriate radiographic equipment, film-screen combinations, and radiographic projections enhances the information obtained from radiographs. Both normal findings and common radiographic abnormalities are discussed. The use of ultrasonography and CT scanning for exotic small mammals and reptiles is described

  18. Beamforming Scheme for 2D Displacement Estimation in Ultrasound Imaging

    Philippe Delachartre

    2005-05-01

    Full Text Available We propose a beamforming scheme for ultrasound imaging leading to the generation of two sets of images, one with oscillations only in the axial direction and one with oscillations only in the lateral direction. Applied to tissue elasticity imaging, this leads to the development of a specific displacement estimation technique that is capable of accurate estimation of two components of the displacement. The mean standard deviation for the axial displacement estimates is 0.0219 times the wavelength of the axial oscillations λz, and for the lateral estimates, it is equal to 0.0164 times the wavelength of the lateral oscillations λx. The method is presented and its feasibility is clearly established by a simulation work.

  19. Diagnostic imaging of shoulder impingement

    Magnetic resonance imaging is a method that has been advancing in the last few years to the modality of choice for diagnostic evaluation of the bone joints, as the method is capable of imaging not only the ossous but also the soft tissue components of the joint. MRI likewise has become an accepted method for diagnostic evaluation of syndromes of the shoulder, with high diagnostic accuracy in detecting rotator cuff lesions, or as an efficient MRI arthrography for evaluation of the instability or lesions of the labrocapsular complex. In the evaluation of early stages of shoulder impingement, the conventional MRI technique as a static technique yields indirect signs which in many cases do not provide the diagnostic certainty required in order to do justice to the functional nature of the syndrome. In these cases, functional MRI for imaging of the arm in abducted position and in rotational movement may offer a chance to early detect impingement and thus identify patients who will profit from treatment at an early stage

  20. Diagnostic imaging of the prostate

    Modalities for the diagnostic imaging of the prostate are surveyed. Transrectal sonography is thought to be the best method for the purpose, because of its non-invasive nature, fine picture quality, sufficient reproductivity and less expensive cost. Up-to-date utilizations of the method are described, such as diagnostic capability, staging, monitoring, screening and intervention. CT is less effective but MRI is promising to visualize internal structure inside the prostate. Two very new techniques, namely, ultrasonic Doppler color flow mapping and positron emission CT (PET), of which application to the prostate is being investigated originally in our laboratory, are introduced. (author) 100 refs

  1. A 2-D imaging heat-flux gauge

    Noel, B.W.; Borella, H.M. (Los Alamos National Lab., NM (United States)); Beshears, D.L.; Sartory, W.K.; Tobin, K.W.; Williams, R.K. (Oak Ridge National Lab., TN (United States)); Turley, W.D. (EG and G Energy Measurements, Inc., Goleta, CA (United States). Santa Barbara Operations)

    1991-07-01

    This report describes a new leadless two-dimensional imaging optical heat-flux gauge. The gauge is made by depositing arrays of thermorgraphic-phosphor (TP) spots onto the faces of a polymethylpentene is insulator. In the first section of the report, we describe several gauge configurations and their prototype realizations. A satisfactory configuration is an array of right triangles on each face that overlay to form squares when the gauge is viewed normal to the surface. The next section of the report treats the thermal conductivity of TPs. We set up an experiment using a comparative longitudinal heat-flow apparatus to measure the previously unknown thermal conductivity of these materials. The thermal conductivity of one TP, Y{sub 2}O{sub 3}:Eu, is 0.0137 W/cm{center dot}K over the temperature range from about 300 to 360 K. The theories underlying the time response of TP gauges and the imaging characteristics are discussed in the next section. Then we discuss several laboratory experiments to (1) demonstrate that the TP heat-flux gauge can be used in imaging applications; (2) obtain a quantum yield that enumerates what typical optical output signal amplitudes can be obtained from TP heat-flux gauges; and (3) determine whether LANL-designed intensified video cameras have sufficient sensitivity to acquire images from the heat-flux gauges. We obtained positive results from all the measurements. Throughout the text, we note limitations, areas where improvements are needed, and where further research is necessary. 12 refs., 25 figs., 4 tabs.

  2. Adaptive Segmentation Method for 2-D Barcode Image Base on Mathematic Morphological

    Jianhua Li

    2013-10-01

    Full Text Available Segmentation is a key process of 2-D barcode identification. In this study we propose a fast adaptive segmentation method that is based on morphological method which is suitable for kinds of 2-D barcode images with different scale, angle and sort. The algorithm is based on mathematical morphology, the basic idea of the algorithm is to use Multi-scale open reconstruction of mathematical morphology to transform the image continuously, then choose whether to terminate by the results of the adjacent image transformation and finally get the final segmentation results by further processing of the images obtain from termination.The proposed approach is applied in experiments on 2-D barcodes with complicated background. The results indicated that the proposed method is very effective in adaptively 2-D barcode image segmentation.

  3. Diagnostic imaging in focal epilepsy

    Focal epilepsies account for 60% of all seizure disorders worldwide. In this review the classic and new classification system of epileptic seizures and syndromes as well as genetic forms are discussed. Magnetic resonance (MR) is the technique of choice for diagnostic imaging in focal epilepsy because of its sensitivity and high tissue contrast. The review is focused on the lack of consensus of imaging protocols and reported findings in refractory epilepsy. The most frequently encountered MRI findings in epilepsy are reported and their imaging characteristics are depicted. Diagnosis of hippocampal sclerosis and malformations of cortical development as two major causes of refractory focal epilepsy is described in details. Some promising new techniques as positron emission tomography computed tomography (PET/CT) and MR and PET/CT fusion are briefly discussed. Also the relevance of adequate imaging in focal epilepsy, some practical points in imaging interpretation and differential diagnosis are highlighted. (author)

  4. Microsecond time-resolved 2D X-ray imaging

    A method is presented which allows to take two-dimensional X-ray images of repetitive processes with recording times in the sub-microsecond range. Various measurements have been performed with a recently introduced novel two-dimensional single photon counter which has been slightly modified in order to determine the exact arrival time of each detected photon. For this purpose a special clock signal is synchronized with the process and is digitized contemporaneously with each event. This technique can be applied even with rate limited detectors and low flux sources, since--unlike in conventional methods, where chopped beams or gated read out electronics are used--all photons are used for the image formation. For the measurements, rapidly moving mechanical systems and conventional X-ray sources have been used, reaching time resolutions of some 10 μs. The technique presented here opens a variety of new biological, medical and industrial applications which will be discussed. As a first application example, three dimensional tomographic reconstructions of rapidly rotating objects (4000 turns/min) are presented

  5. 2D IMAGE BASED SIEVING FOR PARTICLE AGGREGATE GRADATION

    Chen Ken; John Zaniewski; Zhao Pan; Yang Ren'er

    2008-01-01

    Acquiring the size gradation for particle aggregates is a common practice in the granule related industry, and mechanical sieving or screening has been the normal method. Among many drawbacks of this conventional means, the major ones are time-consuming, labor-intensive, and being unable to provide real-time feedback for process control. In this letter, an optical sieving approach is introduced. The two-dimensional images are used to develop methods for inferring particle volume and sieving behavior for gradation purposes. And a combination of deterministic and probabilistic methods is described to predict the sieving behaviors of the particles and to construct the gradation curves for the aggregate sample. Comparison of the optical sieving with standard mechanical sieving shows good correlation.

  6. Diagnostic imaging of compression neuropathy

    Compression-induced neuropathy of peripheral nerves can cause severe pain of the foot and ankle. Early diagnosis is important to institute prompt treatment and to minimize potential injury. Although clinical examination combined with electrophysiological studies remain the cornerstone of the diagnostic work-up, in certain cases, imaging may provide key information with regard to the exact anatomic location of the lesion or aid in narrowing the differential diagnosis. In other patients with peripheral neuropathies of the foot and ankle, imaging may establish the etiology of the condition and provide information crucial for management and/or surgical planning. MR imaging and ultrasound provide direct visualization of the nerve and surrounding abnormalities. Bony abnormalities contributing to nerve compression are best assessed by radiographs and CT. Knowledge of the anatomy, the etiology, typical clinical findings, and imaging features of peripheral neuropathies affecting the peripheral nerves of the foot and ankle will allow for a more confident diagnosis. (orig.)

  7. Diagnostic imaging in child abuse

    Diagnostic imaging in child abuse plays an important role and includes the depiction of skeletal injuries, soft tissue lesions, visceral injuries in ''battered child syndrome'' and brain injuries in ''shaken baby syndrome''. The use of appropriate imaging modalities allows specific fractures to be detected, skeletal lesions to be dated and the underlying mechanism of the lesion to be described. The imaging results must be taken into account when assessing the clinical history, clinical findings and differential diagnoses. Computed tomography (CT) and magnetic resonance imaging (MRI) examinations must be performed in order to detect lesions of the central nervous system (CNS) immediately. CT is necessary in the initial diagnosis to delineate oedema and haemorrhages. Early detection of brain injuries in children with severe neurological symptoms can prevent serious late sequelae. MRI is performed in follow-up investigations and is used to describe residual lesions, including parenchymal findings. (orig.)

  8. Contributions in compression of 3D medical images and 2D images

    The huge amounts of volumetric data generated by current medical imaging techniques in the context of an increasing demand for long term archiving solutions, as well as the rapid development of distant radiology make the use of compression inevitable. Indeed, if the medical community has sided until now with compression without losses, most of applications suffer from compression ratios which are too low with this kind of compression. In this context, compression with acceptable losses could be the most appropriate answer. So, we propose a new loss coding scheme based on 3D (3 dimensional) Wavelet Transform and Dead Zone Lattice Vector Quantization 3D (DZLVQ) for medical images. Our algorithm has been evaluated on several computerized tomography (CT) and magnetic resonance image volumes. The main contribution of this work is the design of a multidimensional dead zone which enables to take into account correlations between neighbouring elementary volumes. At high compression ratios, we show that it can out-perform visually and numerically the best existing methods. These promising results are confirmed on head CT by two medical patricians. The second contribution of this document assesses the effect with-loss image compression on CAD (Computer-Aided Decision) detection performance of solid lung nodules. This work on 120 significant lungs images shows that detection did not suffer until 48:1 compression and still was robust at 96:1. The last contribution consists in the complexity reduction of our compression scheme. The first allocation dedicated to 2D DZLVQ uses an exponential of the rate-distortion (R-D) functions. The second allocation for 2D and 3D medical images is based on block statistical model to estimate the R-D curves. These R-D models are based on the joint distribution of wavelet vectors using a multidimensional mixture of generalized Gaussian (MMGG) densities. (author)

  9. Automatic Masking for Robust 3D-2D Image Registration in Image-Guided Spine Surgery

    Ketcha, M. D.; De Silva, T.; Uneri, A.; Kleinszig, G.; Vogt, S.; Wolinsky, J.-P.; Siewerdsen, J. H.

    2016-01-01

    During spinal neurosurgery, patient-specific information, planning, and annotation such as vertebral labels can be mapped from preoperative 3D CT to intraoperative 2D radiographs via image-based 3D-2D registration. Such registration has been shown to provide a potentially valuable means of decision support in target localization as well as quality assurance of the surgical product. However, robust registration can be challenged by mismatch in image content between the preoperative CT and intraoperative radiographs, arising, for example, from anatomical deformation or the presence of surgical tools within the radiograph. In this work, we develop and evaluate methods for automatically mitigating the effect of content mismatch by leveraging the surgical planning data to assign greater weight to anatomical regions known to be reliable for registration and vital to the surgical task while removing problematic regions that are highly deformable or often occluded by surgical tools. We investigated two approaches to assigning variable weight (i.e., "masking") to image content and/or the similarity metric: (1) masking the preoperative 3D CT ("volumetric masking"); and (2) masking within the 2D similarity metric calculation ("projection masking"). The accuracy of registration was evaluated in terms of projection distance error (PDE) in 61 cases selected from an IRB-approved clinical study. The best performing of the masking techniques was found to reduce the rate of gross failure (PDE > 20 mm) from 11.48% to 5.57% in this challenging retrospective data set. These approaches provided robustness to content mismatch and eliminated distinct failure modes of registration. Such improvement was gained without additional workflow and has motivated incorporation of the masking methods within a system under development for prospective clinical studies.

  10. Hierarchical Segmentation Enhances Diagnostic Imaging

    2007-01-01

    Bartron Medical Imaging LLC (BMI), of New Haven, Connecticut, gained a nonexclusive license from Goddard Space Flight Center to use the RHSEG software in medical imaging. To manage image data, BMI then licensed two pattern-matching software programs from NASA's Jet Propulsion Laboratory that were used in image analysis and three data-mining and edge-detection programs from Kennedy Space Center. More recently, BMI made NASA history by being the first company to partner with the Space Agency through a Cooperative Research and Development Agreement to develop a 3-D version of RHSEG. With U.S. Food and Drug Administration clearance, BMI will sell its Med-Seg imaging system with the 2-D version of the RHSEG software to analyze medical imagery from CAT and PET scans, MRI, ultrasound, digitized X-rays, digitized mammographies, dental X-rays, soft tissue analyses, moving object analyses, and soft-tissue slides such as Pap smears for the diagnoses and management of diseases. Extending the software's capabilities to three dimensions will eventually enable production of pixel-level views of a tumor or lesion, early identification of plaque build-up in arteries, and identification of density levels of microcalcification in mammographies.

  11. Recovering 3D tumor locations from 2D bioluminescence images and registration with CT images

    Huang, Xiaolei; Metaxas, Dimitris N.; Menon, Lata G.; Mayer-Kuckuk, Philipp; Bertino, Joseph R.; Banerjee, Debabrata

    2006-02-01

    In this paper, we introduce a novel and efficient algorithm for reconstructing the 3D locations of tumor sites from a set of 2D bioluminescence images which are taken by a same camera but after continually rotating the object by a small angle. Our approach requires a much simpler set up than those using multiple cameras, and the algorithmic steps in our framework are efficient and robust enough to facilitate its use in analyzing the repeated imaging of a same animal transplanted with gene marked cells. In order to visualize in 3D the structure of the tumor, we also co-register the BLI-reconstructed crude structure with detailed anatomical structure extracted from high-resolution microCT on a single platform. We present our method using both phantom studies and real studies on small animals.

  12. 3-D Reconstruction From 2-D Radiographic Images and Its Application to Clinical Veterinary Medicine

    Hamamoto, Kazuhiko; Sato, Motoyoshi

    3D imaging technique is very important and indispensable in diagnosis. The main stream of the technique is one in which 3D image is reconstructed from a set of slice images, such as X-ray CT and MRI. However, these systems require large space and high costs. On the other hand, a low cost and small size 3D imaging system is needed in clinical veterinary medicine, for example, in the case of diagnosis in X-ray car or pasture area. We propose a novel 3D imaging technique using 2-D X-ray radiographic images. This system can be realized by cheaper system than X-ray CT and enables to get 3D image in X-ray car or portable X-ray equipment. In this paper, a 3D visualization technique from 2-D radiographic images is proposed and several reconstructions are shown. These reconstructions are evaluated by veterinarians.

  13. Digital Image Analysis of Cells : Applications in 2D, 3D and Time

    Pinidiyaarachchi, Amalka

    2009-01-01

    Light microscopes are essential research tools in biology and medicine. Cell and tissue staining methods have improved immensely over the years and microscopes are now equipped with digital image acquisition capabilities. The image data produced require development of specialized analysis methods. This thesis presents digital image analysis methods for cell image data in 2D, 3D and time sequences. Stem cells have the capability to differentiate into specific cell types. The mechanism behind di...

  14. Recent Advancements in Microwave Imaging Plasma Diagnostics

    H. Park; C.C. Chang; B.H. Deng; C.W. Domier; A.J.H. Donni; K. Kawahata; C. Liang; X.P. Liang; H.J. Lu; N.C. Luhmann, Jr.; A. Mase; H. Matsuura; E. Mazzucato; A. Miura; K. Mizuno; T. Munsat; K. and Y. Nagayama; M.J. van de Pol; J. Wang; Z.G. Xia; W-K. Zhang

    2002-03-26

    Significant advances in microwave and millimeter wave technology over the past decade have enabled the development of a new generation of imaging diagnostics for current and envisioned magnetic fusion devices. Prominent among these are revolutionary microwave electron cyclotron emission imaging (ECEI), microwave phase imaging interferometers, imaging microwave scattering and microwave imaging reflectometer (MIR) systems for imaging electron temperature and electron density fluctuations (both turbulent and coherent) and profiles (including transport barriers) on toroidal devices such as tokamaks, spherical tori, and stellarators. The diagnostic technology is reviewed, and typical diagnostic systems are analyzed. Representative experimental results obtained with these novel diagnostic systems are also presented.

  15. Recent Advancements in Microwave Imaging Plasma Diagnostics

    Significant advances in microwave and millimeter wave technology over the past decade have enabled the development of a new generation of imaging diagnostics for current and envisioned magnetic fusion devices. Prominent among these are revolutionary microwave electron cyclotron emission imaging (ECEI), microwave phase imaging interferometers, imaging microwave scattering and microwave imaging reflectometer (MIR) systems for imaging electron temperature and electron density fluctuations (both turbulent and coherent) and profiles (including transport barriers) on toroidal devices such as tokamaks, spherical tori, and stellarators. The diagnostic technology is reviewed, and typical diagnostic systems are analyzed. Representative experimental results obtained with these novel diagnostic systems are also presented

  16. Computer assisted determination of acetabular cup orientation using 2D-3D image registration

    2D-3D image-based registration methods have been developed to measure acetabular cup orientation after total hip arthroplasty (THA). These methods require registration of both the prosthesis and the CT images to 2D radiographs and compute implant position with respect to a reference. The application of these methods is limited in clinical practice due to two limitations: (1) the requirement of a computer-aided design (CAD) model of the prosthesis, which may be unavailable due to the proprietary concerns of the manufacturer, and (2) the requirement of either multiple radiographs or radiograph-specific calibration, usually unavailable for retrospective studies. In this paper, we propose a new method to address these limitations. A new formulation for determination of post-operative cup orientation, which couples a radiographic measurement with 2D-3D image matching, was developed. In our formulation, the radiographic measurement can be obtained with known methods so that the challenge lies in the 2D-3D image matching. To solve this problem, a hybrid 2D-3D registration scheme combining a landmark-to-ray 2D-3D alignment with a robust intensity-based 2D-3D registration was used. The hybrid 2D-3D registration scheme allows computing both the post-operative cup orientation with respect to an anatomical reference and the pelvic tilt and rotation with respect to the X-ray imaging table/plate. The method was validated using 2D adult cadaver hips. Using the hybrid 2D-3D registration scheme, our method showed a mean accuracy of 1.0 ± 0.7 (range from 0.1 to 2.0 ) for inclination and 1.7 ± 1.2 (range from 0.0 to 3.9 ) for anteversion, taking the measurements from post-operative CT images as ground truths. Our new solution formulation and the hybrid 2D-3D registration scheme facilitate estimation of post-operative cup orientation and measurement of pelvic tilt and rotation. (orig.)

  17. Computer assisted determination of acetabular cup orientation using 2D-3D image registration

    Zheng, Guoyan; Zhang, Xuan [University of Bern, Institute for Surgical Technology and Biomechanics, Bern (Switzerland)

    2010-09-15

    2D-3D image-based registration methods have been developed to measure acetabular cup orientation after total hip arthroplasty (THA). These methods require registration of both the prosthesis and the CT images to 2D radiographs and compute implant position with respect to a reference. The application of these methods is limited in clinical practice due to two limitations: (1) the requirement of a computer-aided design (CAD) model of the prosthesis, which may be unavailable due to the proprietary concerns of the manufacturer, and (2) the requirement of either multiple radiographs or radiograph-specific calibration, usually unavailable for retrospective studies. In this paper, we propose a new method to address these limitations. A new formulation for determination of post-operative cup orientation, which couples a radiographic measurement with 2D-3D image matching, was developed. In our formulation, the radiographic measurement can be obtained with known methods so that the challenge lies in the 2D-3D image matching. To solve this problem, a hybrid 2D-3D registration scheme combining a landmark-to-ray 2D-3D alignment with a robust intensity-based 2D-3D registration was used. The hybrid 2D-3D registration scheme allows computing both the post-operative cup orientation with respect to an anatomical reference and the pelvic tilt and rotation with respect to the X-ray imaging table/plate. The method was validated using 2D adult cadaver hips. Using the hybrid 2D-3D registration scheme, our method showed a mean accuracy of 1.0 {+-} 0.7 (range from 0.1 to 2.0 ) for inclination and 1.7 {+-} 1.2 (range from 0.0 to 3.9 ) for anteversion, taking the measurements from post-operative CT images as ground truths. Our new solution formulation and the hybrid 2D-3D registration scheme facilitate estimation of post-operative cup orientation and measurement of pelvic tilt and rotation. (orig.)

  18. 50-kHz-rate 2D imaging of temperature and H2O concentration at the exhaust plane of a J85 engine using hyperspectral tomography

    Ma, Lin; Li, Xuesong; Sanders, Scott T; Caswell, Andrew W.; Roy, Sukesh; Plemmons, David H.; Gord, James R.

    2013-01-01

    This paper describes a novel laser diagnostic and its demonstration in a practical aero propulsion engine (General Electric J85). The diagnostic technique, named hyperspectral tomography (HT), enables simultaneous 2-dimensional (2D) imaging of temperature and water-vapor concentration at 225 spatial grid points with a temporal response up to 50 kHz. To our knowledge, this is the first time that such sensing capabilities have been reported. This paper introduces the principles of the HT techni...

  19. A simple model for 2D image upconversion of incoherent light

    Dam, Jeppe Seidelin; Pedersen, Christian; Tidemand-Lichtenberg, Peter

    2011-01-01

    We present a simple theoretical model for 2 dimensional (2-D) image up-conversion of incoherent light. While image upconversion has been known for more than 40 years, the technology has been hindered by very low conversion quantum efficiency (~10-7). We show that our implementation compared to...

  20. Development of 2D casting process CAD system based on PDF/image files

    Tang Hongtao; Zhou Jianxin; Wang Lin; Liao Dunming; Tao Qing

    2014-01-01

    A casting process CAD is put forward to design and draw casting process. The 2D casting process CAD, most of the current systems are developed based on one certain version of the AutoCAD system. However the application of these 2D casting process CAD systems in foundry enterprises are restricted because they have several deficiencies, such as being overly dependent on the AutoCAD system, and some part files based on PDF format can not be opened directly. To overcome these deficiencies, for the first time an innovative 2D casting process CAD system based on PDF and image format file has been proposed, which breaks through the traditional research and application notion of the 2D casting process CAD system based on AutoCAD. Several key technologies of this system such as coordinate transformation, CAD interactive drawing, file storage, PDF and image format files display, and image recognition technologies were described in detail. A practical 2D CAD casting process system named HZCAD2D(PDF) was developed, which is capable of designing and drawing the casting process on the part drawing based on the PDF format directly, without spending time on drawing the part produced by AutoCAD system. Final y, taking two actual castings as examples, the casting processes were drawn using this system, demonstrating that this system can significantly shorten the cycle of casting process designing.

  1. [Over diagnostic imaging in cardiology].

    Carpeggiani, Clara

    2014-03-01

    Medical imaging is one of the major cause of rising health care costs. Diagnostic imaging has increased more rapidly than any other component of medical care. About 5 billion imaging tests are performed worldwide each year. According to recent estimates, at least one-third of all examinations are partially or totally inappropriate. Two out of 3 imaging tests employ ionizing radiations with radiology or nuclear medicine. The medical use of radiation is the largest man-made source of radiation exposure. Medical X-rays and γ-rays are a proven human carcinogen. The attributable long-term extra-risk of cancer due to diagnostic testing is around 10% in industrialized countries. Cardiologists prescribe and/or directly perform >50% of all imaging examinations, accounting for about two-thirds of the total effective dose given to patients. The dose of common cardiological examinations may be significant: 500 chest X-rays= a stress scintigraphy with sestamibi, 750 chest X-rays= a Multislice Computed Tomography, 1,000 chest X-rays= a coronary angiography and stenting. Unfortunately, few doctors are aware of the level of radiation their patients are exposed to during radiological tests and more intensive use of ionizing testing was not associated with greater awareness. Also as a consequence of unawareness, the rate of inappropriate examinations is unacceptably high in cardiology, even for procedures with high radiation load. Higher exposure doses correspond to higher long-term risks; there are no safe doses, and all doses add up in determining the cumulative risks over a lifetime. Doctors should make every effort so that «each patient should get the right imaging exam, at the right time, with the right radiation dose», as suggested by US Food and Drug Administration in the 2010 initiative to reduce unnecessary radiation exposure from medical imaging. This is best obtained through a systematic implementation of the "3 A's strategy" proposed by the International Atomic Energy

  2. 2dx--user-friendly image processing for 2D crystals.

    Gipson, Bryant; Zeng, Xiangyan; Zhang, Zi Yan; Stahlberg, Henning

    2007-01-01

    Electron crystallography determines the structure of two-dimensional (2D) membrane protein crystals and other 2D crystal systems. Cryo-transmission electron microscopy records high-resolution electron micrographs, which require computer processing for three-dimensional structure reconstruction. We present a new software system 2dx, which is designed as a user-friendly, platform-independent software package for electron crystallography. 2dx assists in the management of an image-processing project, guides the user through the processing of 2D crystal images, and provides transparence for processing tasks and results. Algorithms are implemented in the form of script templates reminiscent of c-shell scripts. These templates can be easily modified or replaced by the user and can also execute modular stand-alone programs from the MRC software or from other image processing software packages. 2dx is available under the GNU General Public License at 2dx.org. PMID:17055742

  3. Quantitative Multiscale Analysis using Different Wavelets in 1D Voice Signal and 2D Image

    Shakhakarmi, Niraj

    2012-01-01

    Mutiscale analysis represents multiresolution scrutiny of a signal to improve its signal quality. Multiresolution analysis of 1D voice signal and 2D image is conducted using DCT, FFT and different wavelets such as Haar, Deubachies, Morlet, Cauchy, Shannon, Biorthogonal, Symmlet and Coiflet deploying the cascaded filter banks based decomposition and reconstruction. The outstanding quantitative analysis of the specified wavelets is done to investigate the signal quality, mean square error, entropy and peak-to-peak SNR at multiscale stage-4 for both 1D voice signal and 2D image. In addition, the 2D image compression performance is significantly found 93.00% in DB-4, 93.68% in bior-4.4, 93.18% in Sym-4 and 92.20% in Coif-2 during the multiscale analysis.

  4. GPU-Based Data Processing for 2-D Microwave Imaging on MAST

    Chorley, J.; Akers, R. J.; Brunner, K.J.; Dipper, Nigel; Freethy, Simon James; Sharples, Ray; Shevchenko, V. F.; Thomas, David Allden; Vann, Roderick G L

    2016-01-01

    The Synthetic Aperture Microwave Imaging (SAMI) diagnostic is a Mega Amp Spherical Tokamak (MAST) diagnostic based at Culham Centre for Fusion Energy. The acceleration of the SAMI diagnostic data-processing code by a graphics processing unit is presented, demonstrating acceleration of up to 60 times compared to the original IDL (Interactive Data Language) data-processing code. SAMI will now be capable of intershot processing allowing pseudo-real-time control so that adjustments and optimizati...

  5. Development of a 2D temperature measurement technique for combustion diagnostics using 2-line atomic fluorescence

    Engstroem, Johan

    2001-01-01

    The present thesis is concerned with the development and application of a novel planar laser-induced fluorescence (PLIF) technique for temperature measurements in a variety of combusting flows. Accurate measurement of temperature is an essential task in combustion diagnostics, since temperature is one of the most fundamental quantities for the characterization of combustion processes. The technique is based on two-line atomic fluorescence (TLAF) from small quantities of atomic indium (In) seeded into the fuel. It has been developed from small-scale experiments in laboratory flames to the point where practical combustion systems can be studied. The technique is conceptually simple and reveals temperature information in the post-flame regions. The viability of the technique has been tested in three extreme measurement situations: in spark ignition engine combustion, in ultra-lean combustion situations such as lean burning aero-engine concepts and, finally, in fuel-rich combustion. TLAF was successfully applied in an optical Sl engine using isooctane as fuel. The wide temperature sensitivity, 700 - 3000 K, of the technique using indium atoms allowed measurements over the entire combustion cycle in the engine to be performed. In applications in lean combustion a potential problem caused by the strong oxidation processes of indium atoms was encountered. This limits measurement times due to deposits of absorbing indium oxide on measurement windows. The seeding requirement is a disadvantage of the technique and can be a limitation in some applications. The results from experiments performed in sooting flames are very promising for thermometry measurements in such environments. Absorption by hydrocarbons and other native species was found to be negligible. Since low laser energies and low seeding concentrations could be used, the technique did not, unlike most other incoherent optical thermometry techniques, suffer interferences from LII of soot particles or LIF from PAH

  6. Analytical characteristics of wavelength dispersive XRF imaging with straight polycapillary and 2D detector

    XRF imaging is analytical method to obtain 2D elemental distribution by using XRF. One of the typical methods of XRF imaging is scanning XRF imaging using micro X-ray beam. For this method, energy dispersive detector is used. However, in energy dispersive scanning XRF imaging, since the sample is scanned with a fixed micro X-ray beam, this method needs long measurement time to obtain elemental images of a wide area. The alternative method for performing XRF imaging in a shorter time is a projection XRF imaging. For this method, incident X-ray is irradiated to a sample in a wide area and fluorescence X-ray is detected by 2D detector. However, since 2D detector has no energy resolution, there is a problem that the identification of the elements can not be performed. Therefore, we proposed the projection XRF imaging combined with wavelength dispersive spectroscopy (WDS). In this paper, we discuss WD-XRF imaging using straight polycapillary and X-ray CCD camera. (author)

  7. Age Estimation Based on AAM and 2D-DCT Features of Facial Images

    Asuman Günay

    2015-02-01

    Full Text Available This paper proposes a novel age estimation method - Global and Local feAture based Age estiMation (GLAAM - relying on global and local features of facial images. Global features are obtained with Active Appearance Models (AAM. Local features are extracted with regional 2D-DCT (2- dimensional Discrete Cosine Transform of normalized facial images. GLAAM consists of the following modules: face normalization, global feature extraction with AAM, local feature extraction with 2D-DCT, dimensionality reduction by means of Principal Component Analysis (PCA and age estimation with multiple linear regression. Experiments have shown that GLAAM outperforms many methods previously applied to the FG-NET database.

  8. Volumetric Synthetic Aperture Imaging with a Piezoelectric 2-D Row-Column Probe.

    Bouzari, Hamed; Engholm, Mathias; Christiansen, Thomas Lehrmann; Beers, Christopher; Lei, Anders; Stuart, Matthias Bo; Nikolov, Svetoslav Ivanov; Thomsen, Erik Vilain; Jensen, Jørgen Arendt

    2016-01-01

    The synthetic aperture (SA) technique can be used for achieving real-time volumetric ultrasound imaging using2-D row-column addressed transducers. This paper investigates SA volumetric imaging performance of an in-houseprototyped 3 MHz λ/2-pitch 62+62 element piezoelectric 2-D row-column addressed transducer array. Utilizingsingle element transmit events, a volume rate of 90 Hz down to 14 cm deep is achieved. Data are obtainedusing the experimental ultrasound scanner SARUS with a 70 MHz sampl...

  9. Imaging techniques in thyroid diagnostics

    Imaging techniques were discussed in a comprehensive manner and in consideration of the rapid recent progress. 30 papers were presented on the subjects of, roughly, radiology, nuclear medicine, and sonography. Apart from conventional radiodiagnostics, which may even yield epidemiological information, the first section also discussed pneumatological functional analysis as a mean of diagnosing tracheal insufficiencies. Thyroid CT is the method of choice in the mediastinal manifestations of thyroid diseases and in examinations of the organs next to the thyroid. Orbital CT yields completely new findings on the pathophysiology, differential diagnosis and therapy of endocrineous orbitopathy. - While the diagnostic value of nuclear spin tomography remains uncertain, thyroid scintiscanning has reached maturity by now. In contrast to scanners, which give a general image, the γ camera can detect regional functional phenomena. Fluorescence scintiscanning, apart from quantification of intrathyroid iodine, enables scintigraphic imaging of the thyroid without incorporation of radioactivity. - The recent progress in thyroid sonography has been dramatic. Apart from the simple and reproducible technique of volumetry, nonstandard echo structures indicate diffuse or focal fine tissue lesions, and sonography has therefore become an accepted technique prior to fine needle biopsy or scintiscanning. (orig.)

  10. Diagnostic imaging of craniofacial trauma and fractures and their sequelae

    The value and applications of the CT modalities are on the rise, particularly since the availability of spiral CT techniques, while conventional native diagnostics is increasingly used for special imaging purposes. Multiplanar spiral CT enables high-quality coronary 2D reconstructions which, in the acute phase, make redundant primary coronary imaging modalities. Exact knowledge of typical fracture patterns facilitates the analysis of images of the relevant facial areas. 3D reconstructions are indispensable in pin-pointed surgery planning, generation of stereolithographic models, and image-guided interventions for examination of post-traumatic deformities. Since a secondary correction only very rarely leads to restitutio ad integrum, it is necessary to detect the therapy-relevant injuries very early, during acute diagnostic imaging, in order to lay the basis for subsequent therapy and restoration of the craniofacial structures and functions. (orig./CB)

  11. Single-photon 2-D imaging X-ray spectrometer employing trapping with four tunnel junctions

    We are developing single-photon 2-D imaging X-ray spectrometers for applications in X-ray astrophysics. The devices employing a Ta strip X-ray absorber with Al traps and a tunnel junction at each end have been tested. They achieve an energy resolution of 26 eV out of 5.9 keV over a limited length (Segall, IEEE Trans., in press) with a 1-D spatial resolution of about 2 μm over the full 160 μm length. By analytical and numerical simulations of the quasiparticle diffusion process, we study related devices with a square Ta absorber having four traps and attached junctions to provide 2-D imaging. The traps give charge division to the corners or to the edges of the square absorber. We find that these devices can give good 2-D spatial resolution. We discuss the operating principle and the factors which affect the spatial resolution

  12. Tensor representation of color images and fast 2D quaternion discrete Fourier transform

    Grigoryan, Artyom M.; Agaian, Sos S.

    2015-03-01

    In this paper, a general, efficient, split algorithm to compute the two-dimensional quaternion discrete Fourier transform (2-D QDFT), by using the special partitioning in the frequency domain, is introduced. The partition determines an effective transformation, or color image representation in the form of 1-D quaternion signals which allow for splitting the N × M-point 2-D QDFT into a set of 1-D QDFTs. Comparative estimates revealing the efficiency of the proposed algorithms with respect to the known ones are given. In particular, a proposed method of calculating the 2r × 2r -point 2-D QDFT uses 18N2 less multiplications than the well-known column-row method and method of calculation based on the symplectic decomposition. The proposed algorithm is simple to apply and design, which makes it very practical in color image processing in the frequency domain.

  13. Automatic 2D-to-3D image conversion using 3D examples from the internet

    Konrad, J.; Brown, G.; Wang, M.; Ishwar, P.; Wu, C.; Mukherjee, D.

    2012-03-01

    The availability of 3D hardware has so far outpaced the production of 3D content. Although to date many methods have been proposed to convert 2D images to 3D stereopairs, the most successful ones involve human operators and, therefore, are time-consuming and costly, while the fully-automatic ones have not yet achieved the same level of quality. This subpar performance is due to the fact that automatic methods usually rely on assumptions about the captured 3D scene that are often violated in practice. In this paper, we explore a radically different approach inspired by our work on saliency detection in images. Instead of relying on a deterministic scene model for the input 2D image, we propose to "learn" the model from a large dictionary of stereopairs, such as YouTube 3D. Our new approach is built upon a key observation and an assumption. The key observation is that among millions of stereopairs available on-line, there likely exist many stereopairs whose 3D content matches that of the 2D input (query). We assume that two stereopairs whose left images are photometrically similar are likely to have similar disparity fields. Our approach first finds a number of on-line stereopairs whose left image is a close photometric match to the 2D query and then extracts depth information from these stereopairs. Since disparities for the selected stereopairs differ due to differences in underlying image content, level of noise, distortions, etc., we combine them by using the median. We apply the resulting median disparity field to the 2D query to obtain the corresponding right image, while handling occlusions and newly-exposed areas in the usual way. We have applied our method in two scenarios. First, we used YouTube 3D videos in search of the most similar frames. Then, we repeated the experiments on a small, but carefully-selected, dictionary of stereopairs closely matching the query. This, to a degree, emulates the results one would expect from the use of an extremely large 3D

  14. Parameterising root system growth models using 2D neutron radiography images

    Schnepf, Andrea; Felderer, Bernd; Vontobel, Peter; Leitner, Daniel

    2013-04-01

    Root architecture is a key factor for plant acquisition of water and nutrients from soil. In particular in view of a second green revolution where the below ground parts of agricultural crops are important, it is essential to characterise and quantify root architecture and its effect on plant resource acquisition. Mathematical models can help to understand the processes occurring in the soil-plant system, they can be used to quantify the effect of root and rhizosphere traits on resource acquisition and the response to environmental conditions. In order to do so, root architectural models are coupled with a model of water and solute transport in soil. However, dynamic root architectural models are difficult to parameterise. Novel imaging techniques such as x-ray computed tomography, neutron radiography and magnetic resonance imaging enable the in situ visualisation of plant root systems. Therefore, these images facilitate the parameterisation of dynamic root architecture models. These imaging techniques are capable of producing 3D or 2D images. Moreover, 2D images are also available in the form of hand drawings or from images of standard cameras. While full 3D imaging tools are still limited in resolutions, 2D techniques are a more accurate and less expensive option for observing roots in their environment. However, analysis of 2D images has additional difficulties compared to the 3D case, because of overlapping roots. We present a novel algorithm for the parameterisation of root system growth models based on 2D images of root system. The algorithm analyses dynamic image data. These are a series of 2D images of the root system at different points in time. Image data has already been adjusted for missing links and artefacts and segmentation was performed by applying a matched filter response. From this time series of binary 2D images, we parameterise the dynamic root architecture model in the following way: First, a morphological skeleton is derived from the binary

  15. Acoustical cross-talk in row–column addressed 2-D transducer arrays for ultrasound imaging

    Christiansen, Thomas Lehrmann; Jensen, Jørgen Arendt; Thomsen, Erik Vilain

    2015-01-01

    The acoustical cross-talk in row–column addressed 2-D transducer arrays for volumetric ultrasound imaging is investigated. Experimental results from a 2.7 MHz, λ/2-pitch capacitive micromachined ultrasonic transducer (CMUT) array with 62 rows and 62 columns are presented and analyzed in the...

  16. Exploring 2D/3D input techniques for medical image analysis

    E.V. Zudilova-Seinstra; P.M.A. Sloot; P.J.H. de Koning; A. Suinesiaputra; R.J. van der Geest; J.H.C. Reiber

    2009-01-01

    We describe a series of experiments that compared the 2D and 3D input methods for selection and positioning tasks related to medical image analysis. For this study, we chose a switchable P5 glove controller, which can be used to provide both 2DOF and 6DOF input control. Our results suggest that for

  17. Evaluation of 2D and 3D glove input applied to medical image analysis

    E.V. Zudilova-Seinstra; P.J.H. de Koning; A. Suinesiaputra; B.W. van Schooten; R.J. van der Geest; J.H.C. Reiber; P.M.A. Sloot

    2010-01-01

    We describe a series of experiments that compared 2D/3D input methods for selection and positioning tasks related to medical image analysis. For our study, we chose a switchable P5 Glove Controller, which can be used to provide both 2DOF and 6DOF input control. Our results suggest that for both task

  18. Volumetric Ultrasound Imaging with Row-Column Addressed 2-D Arrays Using Spatial Matched Filter Beamforming

    Bouzari, Hamed; Engholm, Mathias; Christiansen, Thomas Lehrmann;

    2015-01-01

    . However, the achievable spatial resolution and contrast of the B-mode images in Delay and Sum (DAS) beamforming are limited by the aperture size and by the operating frequency. This paper, investigates Spatial Matched Filter (SMF) beamforming on row-column addressed 2-D arrays to increase spatial...

  19. 3D multiple-point statistics simulation using 2D training images

    Comunian, A.; Renard, P.; Straubhaar, J.

    2012-03-01

    One of the main issues in the application of multiple-point statistics (MPS) to the simulation of three-dimensional (3D) blocks is the lack of a suitable 3D training image. In this work, we compare three methods of overcoming this issue using information coming from bidimensional (2D) training images. One approach is based on the aggregation of probabilities. The other approaches are novel. One relies on merging the lists obtained using the impala algorithm from diverse 2D training images, creating a list of compatible data events that is then used for the MPS simulation. The other (s2Dcd) is based on sequential simulations of 2D slices constrained by the conditioning data computed at the previous simulation steps. These three methods are tested on the reproduction of two 3D images that are used as references, and on a real case study where two training images of sedimentary structures are considered. The tests show that it is possible to obtain 3D MPS simulations with at least two 2D training images. The simulations obtained, in particular those obtained with the s2Dcd method, are close to the references, according to a number of comparison criteria. The CPU time required to simulate with the method s2Dcd is from two to four orders of magnitude smaller than the one required by a MPS simulation performed using a 3D training image, while the results obtained are comparable. This computational efficiency and the possibility of using MPS for 3D simulation without the need for a 3D training image facilitates the inclusion of MPS in Monte Carlo, uncertainty evaluation, and stochastic inverse problems frameworks.

  20. A comparison of 2D and 3D digital image correlation for a membrane under inflation

    Murienne, Barbara J.; Nguyen, Thao D.

    2016-02-01

    Three-dimensional (3D) digital image correlation (DIC) is becoming widely used to characterize the behavior of structures undergoing 3D deformations. However, the use of 3D-DIC can be challenging under certain conditions, such as high magnification, and therefore small depth of field, or a highly controlled environment with limited access for two-angled cameras. The purpose of this study is to compare 2D-DIC and 3D-DIC for the same inflation experiment and evaluate whether 2D-DIC can be used when conditions discourage the use of a stereo-vision system. A latex membrane was inflated vertically to 5.41 kPa (reference pressure), then to 7.87 kPa (deformed pressure). A two-camera stereo-vision system acquired top-down images of the membrane, while a single camera system simultaneously recorded images of the membrane in profile. 2D-DIC and 3D-DIC were used to calculate horizontal (in the membrane plane) and vertical (out of the membrane plane) displacements, and meridional strain. Under static conditions, the baseline uncertainty in horizontal displacement and strain were smaller for 3D-DIC than 2D-DIC. However, the opposite was observed for the vertical displacement, for which 2D-DIC had a smaller baseline uncertainty. The baseline absolute error in vertical displacement and strain were similar for both DIC methods, but it was larger for 2D-DIC than 3D-DIC for the horizontal displacement. Under inflation, the variability in the measurements were larger than under static conditions for both DIC methods. 2D-DIC showed a smaller variability in displacements than 3D-DIC, especially for the vertical displacement, but a similar strain uncertainty. The absolute difference in the average displacements and strain between 3D-DIC and 2D-DIC were in the range of the 3D-DIC variability. Those findings suggest that 2D-DIC might be used as an alternative to 3D-DIC to study the inflation response of materials under certain conditions.

  1. Electron cyclotron emission imaging diagnostic system for Rijnhuizen Tokamak Project

    A 16-channel electron cyclotron emission (ECE) imaging diagnostic system has been developed and installed on the Rijnhuizen Tokamak Project for measuring plasma electron cyclotron emission with a temporal resolution of 2 μs. The high spatial resolution of the system is achieved by utilizing a low cost linear mixer/receiver array. Unlike conventional ECE diagnostics, the sample volumes of the ECE imaging system are aligned vertically, and can be shifted across the plasma cross-section by varying the local oscillator frequency, making possible 2D measurements of electron temperature profiles and fluctuations. The poloidal/radial wavenumber spectra and correlation lengths of Te fluctuations in the plasma core can also be obtained by properly positioning the focal plane of the imaging system. Due to these unique features, ECE imaging is an ideal tool for plasma transport study. Technical details of the system are described, together with preliminary experimental results. copyright 1999 American Institute of Physics

  2. Diagnostic Imaging in Snakes and Lizards

    Banzato , Tommaso

    2013-01-01

    The increasing popularity of snakes and lizards as pets has led to an increasing demand of specialised veterinary duties in these animals. Diagnostic imaging is often a fundamental step of the clinical investigation. The interpretation of diagnostic images is complex and requires a broad knowledge of anatomy, physiology and pathology of the species object of the clinical investigation. Moreover, in order to achieve a correct diagnosis, the comparison between normal and abnormal diagnostic im...

  3. New applications for the touchscreen in 2D and 3D medical imaging workstations

    Hinckley, Ken; Goble, John C.; Pausch, Randy; Kassell, Neal F.

    1995-04-01

    We present a new interface technique which augments a 3D user interface based on the physical manipulation of tools, or props, with a touchscreen. This hybrid interface intuitively and seamlessly combines 3D input with more traditional 2D input in the same user interface. Example 2D interface tasks of interest include selecting patient images from a database, browsing through axial, coronal, and sagittal image slices, or adjusting image center and window parameters. Note the facility with which a touchscreen can be used: the surgeon can move in 3D using the props, and then, without having to put the props down, the surgeon can reach out and touch the screen to perform 2D tasks. Based on previous work by Sears, we provide touchscreen users with visual feedback in the form of a small cursor which appears above the finger, allowing targets much smaller than the finger itself to be selected. Based on our informal user observations to date, this touchscreen stabilization algorithm allows targets as small as 1.08 mm X 1.08 mm to be selected by novices, and makes possible selection of targets as small as 0.27 mm X 0.27 mm after some training. Based on implemented prototype systems, we suggest that touchscreens offer not only intuitive 2D input which is well accepted by physicians, but that touchscreens also offer fast and accurate input which blends well with 3D interaction techniques.

  4. Progressive attenuation fields: Fast 2D-3D image registration without precomputation

    Computation of digitally reconstructed radiograph (DRR) images is the rate-limiting step in most current intensity-based algorithms for the registration of three-dimensional (3D) images to two-dimensional (2D) projection images. This paper introduces and evaluates the progressive attenuation field (PAF), which is a new method to speed up DRR computation. A PAF is closely related to an attenuation field (AF). A major difference is that a PAF is constructed on the fly as the registration proceeds; it does not require any precomputation time, nor does it make any prior assumptions of the patient pose or limit the permissible range of patient motion. A PAF effectively acts as a cache memory for projection values once they are computed, rather than as a lookup table for precomputed projections like standard AFs. We use a cylindrical attenuation field parametrization, which is better suited for many medical applications of 2D-3D registration than the usual two-plane parametrization. The computed attenuation values are stored in a hash table for time-efficient storage and access. Using clinical gold-standard spine image data sets from five patients, we demonstrate consistent speedups of intensity-based 2D-3D image registration using PAF DRRs by a factor of 10 over conventional ray casting DRRs with no decrease of registration accuracy or robustness

  5. 2D and 3D optical diagnostic techniques applied to Madonna dei Fusi by Leonardo da Vinci

    Fontana, R.; Gambino, M. C.; Greco, M.; Marras, L.; Materazzi, M.; Pampaloni, E.; Pelagotti, A.; Pezzati, L.; Poggi, P.; Sanapo, C.

    2005-06-01

    3D measurement and modelling have been traditionally applied to statues, buildings, archeological sites or similar large structures, but rarely to paintings. Recently, however, 3D measurements have been performed successfully also on easel paintings, allowing to detect and document the painting's surface. We used 3D models to integrate the results of various 2D imaging techniques on a common reference frame. These applications show how the 3D shape information, complemented with 2D colour maps as well as with other types of sensory data, provide the most interesting information. The 3D data acquisition was carried out by means of two devices: a high-resolution laser micro-profilometer, composed of a commercial distance meter mounted on a scanning device, and a laser-line scanner. The 2D data acquisitions were carried out using a scanning device for simultaneous RGB colour imaging and IR reflectography, and a UV fluorescence multispectral image acquisition system. We present here the results of the techniques described, applied to the analysis of an important painting of the Italian Reinassance: `Madonna dei Fusi', attributed to Leonardo da Vinci.

  6. Simple fractal method of assessment of histological images for application in medical diagnostics

    Klonowski, Wlodzimierz; Stepien, Robert; Stepien, Pawel

    2010-01-01

    We propose new method of assessment of histological images for medical diagnostics. 2-D image is preprocessed to form 1-D landscapes or 1-D signature of the image contour and then their complexity is analyzed using Higuchi's fractal dimension method. The method may have broad medical application, from choosing implant materials to differentiation between benign masses and malignant breast tumors.

  7. Simultaneous 3D–2D image registration and C-arm calibration: Application to endovascular image-guided interventions

    Mitrović, Uroš [Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, Ljubljana 1000, Slovenia and Cosylab, Control System Laboratory, Teslova ulica 30, Ljubljana 1000 (Slovenia); Pernuš, Franjo [Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, Ljubljana 1000 (Slovenia); Likar, Boštjan; Špiclin, Žiga, E-mail: ziga.spiclin@fe.uni-lj.si [Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, Ljubljana 1000, Slovenia and Sensum, Computer Vision Systems, Tehnološki Park 21, Ljubljana 1000 (Slovenia)

    2015-11-15

    Purpose: Three-dimensional to two-dimensional (3D–2D) image registration is a key to fusion and simultaneous visualization of valuable information contained in 3D pre-interventional and 2D intra-interventional images with the final goal of image guidance of a procedure. In this paper, the authors focus on 3D–2D image registration within the context of intracranial endovascular image-guided interventions (EIGIs), where the 3D and 2D images are generally acquired with the same C-arm system. The accuracy and robustness of any 3D–2D registration method, to be used in a clinical setting, is influenced by (1) the method itself, (2) uncertainty of initial pose of the 3D image from which registration starts, (3) uncertainty of C-arm’s geometry and pose, and (4) the number of 2D intra-interventional images used for registration, which is generally one and at most two. The study of these influences requires rigorous and objective validation of any 3D–2D registration method against a highly accurate reference or “gold standard” registration, performed on clinical image datasets acquired in the context of the intervention. Methods: The registration process is split into two sequential, i.e., initial and final, registration stages. The initial stage is either machine-based or template matching. The latter aims to reduce possibly large in-plane translation errors by matching a projection of the 3D vessel model and 2D image. In the final registration stage, four state-of-the-art intrinsic image-based 3D–2D registration methods, which involve simultaneous refinement of rigid-body and C-arm parameters, are evaluated. For objective validation, the authors acquired an image database of 15 patients undergoing cerebral EIGI, for which accurate gold standard registrations were established by fiducial marker coregistration. Results: Based on target registration error, the obtained success rates of 3D to a single 2D image registration after initial machine-based and

  8. Simultaneous 3D–2D image registration and C-arm calibration: Application to endovascular image-guided interventions

    Purpose: Three-dimensional to two-dimensional (3D–2D) image registration is a key to fusion and simultaneous visualization of valuable information contained in 3D pre-interventional and 2D intra-interventional images with the final goal of image guidance of a procedure. In this paper, the authors focus on 3D–2D image registration within the context of intracranial endovascular image-guided interventions (EIGIs), where the 3D and 2D images are generally acquired with the same C-arm system. The accuracy and robustness of any 3D–2D registration method, to be used in a clinical setting, is influenced by (1) the method itself, (2) uncertainty of initial pose of the 3D image from which registration starts, (3) uncertainty of C-arm’s geometry and pose, and (4) the number of 2D intra-interventional images used for registration, which is generally one and at most two. The study of these influences requires rigorous and objective validation of any 3D–2D registration method against a highly accurate reference or “gold standard” registration, performed on clinical image datasets acquired in the context of the intervention. Methods: The registration process is split into two sequential, i.e., initial and final, registration stages. The initial stage is either machine-based or template matching. The latter aims to reduce possibly large in-plane translation errors by matching a projection of the 3D vessel model and 2D image. In the final registration stage, four state-of-the-art intrinsic image-based 3D–2D registration methods, which involve simultaneous refinement of rigid-body and C-arm parameters, are evaluated. For objective validation, the authors acquired an image database of 15 patients undergoing cerebral EIGI, for which accurate gold standard registrations were established by fiducial marker coregistration. Results: Based on target registration error, the obtained success rates of 3D to a single 2D image registration after initial machine-based and

  9. A New 2D Corner Detector for Extracting Landmarks from Brain MR Images

    Mohammadi, Gelareh; Fatemizadeh, Emad

    2007-01-01

    Point-based registration of images strongly depends on the extraction of suitable landmarks. Recently, various 2D operators have been proposed for the detection of corner points but most of them are not effective for medical images that need a high accuracy. In this paper we have proposed a new automatic corner detector based on the covariance between the small region of support around a central pixel and its rotated one. The main goal of this paper is medical images so we especially focus on...

  10. Multichannel reconfigurable measurement system for hot plasma diagnostics based on GEM-2D detector

    Wojenski, A. J.; Kasprowicz, G.; Pozniak, K. T.; Byszuk, A.; Chernyshova, M.; Czarski, T.; Jablonski, S.; Juszczyk, B.; Zienkiewicz, P.

    2015-12-01

    In the future magnetically confined fusion research reactors (e.g. ITER tokamak), precise determination of the level of the soft X-ray radiation of plasma with temperature above 30 keV (around 350 mln K) will be very important in plasma parameters optimization. This paper presents the first version of a designed spectrography measurement system. The system is already installed at JET tokamak. Based on the experience gained from the project, the new generation of hardware for spectrography measurements, was designed and also described in the paper. The GEM detector readout structure was changed to 2D in order to perform measurements of i.e. laser generated plasma. The hardware structure of the system was redesigned in order to provide large number of high speed input channels. Finally, this paper also covers the issue of new control software, necessary to set-up a complete system of certain complexity and perform data acquisition. The main goal of the project was to develop a new version of the system, which includes upgraded structure and data transmission infrastructure (i.e. handling large number of measurement channels, high sampling rate).

  11. Detecting myocardial ischemia with 2-D CVIB imaging method--an in vivo animal experiment study

    JIANG Yong; BAI Jing; YING Kui; CHENG Kezheng; YU Can

    2004-01-01

    A 2-D cyclic variation of integrated backscatter (CVIB) imaging method was established for detecting myocardial ischemia. To demonstrate the feasibility and validity of this method, animal experiments were conducted. Acute myocardial ischemia was induced by occluding left anterior descending coronary artery in 10 anesthetized open-chest dogs. While scanning the normal hearts and the ischemic hearts with a B scanner, digital radiofrequency data were acquired by a real-time acquisition system in synchronism. The offline analysis to the radio-frequency signal with the 2-D CVIB imaging method was performed to verify the consistency between the imaging result and the design of the experiment. In addition, 4 dogs in experiment were treated with the heart pacemaker in order to investigate the influence of changing in heart rate on the detection of ischemic myocardium with the proposed method. The experimental result showed that the 2-D CVIB imaging method succeeded in detecting the ischemic myocardium and is a new non-invasive way for the cardiologists to both quantitatively and visually evaluate the contractile performance of the myocardium.

  12. A new efficient 2D combined with 3D CAD system for solitary pulmonary nodule detection in CT images

    Xing Li

    2011-06-01

    Full Text Available Lung cancer has become one of the leading causes of death in the world. Clear evidence shows that early discovery, early diagnosis and early treatment of lung cancer can significantly increase the chance of survival for patients. Lung Computer-Aided Diagnosis (CAD is a potential method to accomplish a range of quantitative tasks such as early cancer and disease detection. Many computer-aided diagnosis (CAD methods, including 2D and 3D approaches, have been proposed for solitary pulmonary nodules (SPNs. However, the detection and diagnosis of SPNs remain challenging in many clinical circumstances. One goal of this work is to develop a two-stage approach that combines the simplicity of 2D and the accuracy of 3D methods. The experimental results show statistically significant differences between the diagnostic accuracy of 2D and 3Dmethods. The results also show that with a very minor drop in diagnostic performance the two-stage approach can significantly reduce the number of nodules needed to be processed by the 3D method, streamlining the computational demand. Finally, all malignant nodules were detected and a very low false-positive detection rate was achieved. The automated extraction of the lung in CT images is the most crucial step in a computer-aided diagnosis (CAD system. In this paper we describe a method, consisting of appropriate techniques, for the automated identification of the pulmonary volume. The performance is evaluated as a fully automated computerized method for the detection of lung nodules in computed tomography (CT scans in the identification of lung cancers that may be missed during visual interpretation.

  13. Radiometer uncertainty equation research of 2D planar scanning PMMW imaging system

    Hu, Taiyang; Xu, Jianzhong; Xiao, Zelong

    2009-07-01

    With advances in millimeter-wave technology, passive millimeter-wave (PMMW) imaging technology has received considerable concerns, and it has established itself in a wide range of military and civil practical applications, such as in the areas of remote sensing, blind landing, precision guidance and security inspection. Both the high transparency of clothing at millimeter wavelengths and the spatial resolution required to generate adequate images combine to make imaging at millimeter wavelengths a natural approach of screening people for concealed contraband detection. And at the same time, the passive operation mode does not present a safety hazard to the person who is under inspection. Based on the description to the design and engineering implementation of a W-band two-dimensional (2D) planar scanning imaging system, a series of scanning methods utilized in PMMW imaging are generally compared and analyzed, followed by a discussion on the operational principle of the mode of 2D planar scanning particularly. Furthermore, it is found that the traditional radiometer uncertainty equation, which is derived from a moving platform, does not hold under this 2D planar scanning mode due to the fact that there is no absolute connection between the scanning rates in horizontal direction and vertical direction. Consequently, an improved radiometer uncertainty equation is carried out in this paper, by means of taking the total time spent on scanning and imaging into consideration, with the purpose of solving the problem mentioned above. In addition, the related factors which affect the quality of radiometric images are further investigated under the improved radiometer uncertainty equation, and ultimately some original results are presented and analyzed to demonstrate the significance and validity of this new methodology.

  14. Gender and ethnicity specific generic elastic models from a single 2D image for novel 2D pose face synthesis and recognition.

    Heo, Jingu; Savvides, Marios

    2012-12-01

    In this paper, we propose a novel method for generating a realistic 3D human face from a single 2D face image for the purpose of synthesizing new 2D face images at arbitrary poses using gender and ethnicity specific models. We employ the Generic Elastic Model (GEM) approach, which elastically deforms a generic 3D depth-map based on the sparse observations of an input face image in order to estimate the depth of the face image. Particularly, we show that Gender and Ethnicity specific GEMs (GE-GEMs) can approximate the 3D shape of the input face image more accurately, achieving a better generalization of 3D face modeling and reconstruction compared to the original GEM approach. We qualitatively validate our method using publicly available databases by showing each reconstructed 3D shape generated from a single image and new synthesized poses of the same person at arbitrary angles. For quantitative comparisons, we compare our synthesized results against 3D scanned data and also perform face recognition using synthesized images generated from a single enrollment frontal image. We obtain promising results for handling pose and expression changes based on the proposed method. PMID:22201062

  15. Injectable Colloidal Gold for Use in Intrafractional 2D Image-Guided Radiation Therapy

    Jølck, Rasmus Irming; Rydhog, Jonas S.; Christensen, Anders Nymark; Hansen, Anders Elias; Bruun, Linda Maria; Schaarup-Jensen, Henrik; von Wenck, Asger Stevner; Borresen, Betina; Kristensen, Annemarie T.; Clausen, Mads Hartvig; Kjær, Andreas; Conradsen, Knut; Larsen, Rasmus; af Rosenschold, Per Munck; Andresen, Thomas Lars

    2015-01-01

    often inserted inside the tumor to improve IGRT precision and to enable monitoring of the tumor position during radiation therapy. In the present article, a liquid fiducial tissue marker is presented, which can be injected into tumor tissue using thin and flexible needles. The liquid fiducial has high...... radio-opacity, which allows for marker-based image guidance in 2D and 3D X-ray imaging during radiation therapy. This is achieved by surface-engineering gold nanoparticles to be highly compatible with a carbohydrate-based gelation matrix. The new fiducial marker is investigated in mice where they are...

  16. Wide area 2D/3D imaging development, analysis and applications

    Langmann, Benjamin

    2014-01-01

    Imaging technology is an important research area and it is widely utilized in a growing number of disciplines ranging from gaming, robotics and automation to medicine. In the last decade 3D imaging became popular mainly driven by the introduction of novel 3D cameras and measuring devices. These cameras are usually limited to indoor scenes with relatively low distances. Benjamin Langmann introduces medium and long-range 2D/3D cameras to overcome these limitations. He reports measurement results for these devices and studies their characteristic behavior. In order to facilitate the application o

  17. 2D image classification for 3D anatomy localization: employing deep convolutional neural networks

    de Vos, Bob D.; Wolterink, Jelmer M.; de Jong, Pim A.; Viergever, Max A.; Išgum, Ivana

    2016-03-01

    Localization of anatomical regions of interest (ROIs) is a preprocessing step in many medical image analysis tasks. While trivial for humans, it is complex for automatic methods. Classic machine learning approaches require the challenge of hand crafting features to describe differences between ROIs and background. Deep convolutional neural networks (CNNs) alleviate this by automatically finding hierarchical feature representations from raw images. We employ this trait to detect anatomical ROIs in 2D image slices in order to localize them in 3D. In 100 low-dose non-contrast enhanced non-ECG synchronized screening chest CT scans, a reference standard was defined by manually delineating rectangular bounding boxes around three anatomical ROIs -- heart, aortic arch, and descending aorta. Every anatomical ROI was automatically identified using a combination of three CNNs, each analyzing one orthogonal image plane. While single CNNs predicted presence or absence of a specific ROI in the given plane, the combination of their results provided a 3D bounding box around it. Classification performance of each CNN, expressed in area under the receiver operating characteristic curve, was >=0.988. Additionally, the performance of ROI localization was evaluated. Median Dice scores for automatically determined bounding boxes around the heart, aortic arch, and descending aorta were 0.89, 0.70, and 0.85 respectively. The results demonstrate that accurate automatic 3D localization of anatomical structures by CNN-based 2D image classification is feasible.

  18. A two-step Hilbert transform method for 2D image reconstruction

    Noo, Frederic; Clackdoyle, Rolf; Pack, Jed D [UCAIR, Department of Radiology, University of Utah, UT (United States)

    2004-09-07

    The paper describes a new accurate two-dimensional (2D) image reconstruction method consisting of two steps. In the first step, the backprojected image is formed after taking the derivative of the parallel projection data. In the second step, a Hilbert filtering is applied along certain lines in the differentiated backprojection (DBP) image. Formulae for performing the DBP step in fan-beam geometry are also presented. The advantage of this two-step Hilbert transform approach is that in certain situations, regions of interest (ROIs) can be reconstructed from truncated projection data. Simulation results are presented that illustrate very similar reconstructed image quality using the new method compared to standard filtered backprojection, and that show the capability to correctly handle truncated projections. In particular, a simulation is presented of a wide patient whose projections are truncated laterally yet for which highly accurate ROI reconstruction is obtained.

  19. A two-step Hilbert transform method for 2D image reconstruction

    The paper describes a new accurate two-dimensional (2D) image reconstruction method consisting of two steps. In the first step, the backprojected image is formed after taking the derivative of the parallel projection data. In the second step, a Hilbert filtering is applied along certain lines in the differentiated backprojection (DBP) image. Formulae for performing the DBP step in fan-beam geometry are also presented. The advantage of this two-step Hilbert transform approach is that in certain situations, regions of interest (ROIs) can be reconstructed from truncated projection data. Simulation results are presented that illustrate very similar reconstructed image quality using the new method compared to standard filtered backprojection, and that show the capability to correctly handle truncated projections. In particular, a simulation is presented of a wide patient whose projections are truncated laterally yet for which highly accurate ROI reconstruction is obtained

  20. A two-step Hilbert transform method for 2D image reconstruction.

    Noo, Frédéric; Clackdoyle, Rolf; Pack, Jed D

    2004-09-01

    The paper describes a new accurate two-dimensional (2D) image reconstruction method consisting of two steps. In the first step, the backprojected image is formed after taking the derivative of the parallel projection data. In the second step, a Hilbert filtering is applied along certain lines in the differentiated backprojection (DBP) image. Formulae for performing the DBP step in fanbeam geometry are also presented. The advantage of this two-step Hilbert transform approach is that in certain situations, regions of interest (ROIs) can be reconstructed from truncated projection data. Simulation results are presented that illustrate very similar reconstructed image quality using the new method compared to standard filtered backprojection, and that show the capability to correctly handle truncated projections. In particular, a simulation is presented of a wide patient whose projections are truncated laterally yet for which highly accurate ROI reconstruction is obtained. PMID:15470913

  1. A software tool for automatic classification and segmentation of 2D/3D medical images

    Modern medical diagnosis utilizes techniques of visualization of human internal organs (CT, MRI) or of its metabolism (PET). However, evaluation of acquired images made by human experts is usually subjective and qualitative only. Quantitative analysis of MR data, including tissue classification and segmentation, is necessary to perform e.g. attenuation compensation, motion detection, and correction of partial volume effect in PET images, acquired with PET/MR scanners. This article presents briefly a MaZda software package, which supports 2D and 3D medical image analysis aiming at quantification of image texture. MaZda implements procedures for evaluation, selection and extraction of highly discriminative texture attributes combined with various classification, visualization and segmentation tools. Examples of MaZda application in medical studies are also provided

  2. Image compression-encryption scheme based on hyper-chaotic system and 2D compressive sensing

    Zhou, Nanrun; Pan, Shumin; Cheng, Shan; Zhou, Zhihong

    2016-08-01

    Most image encryption algorithms based on low-dimensional chaos systems bear security risks and suffer encryption data expansion when adopting nonlinear transformation directly. To overcome these weaknesses and reduce the possible transmission burden, an efficient image compression-encryption scheme based on hyper-chaotic system and 2D compressive sensing is proposed. The original image is measured by the measurement matrices in two directions to achieve compression and encryption simultaneously, and then the resulting image is re-encrypted by the cycle shift operation controlled by a hyper-chaotic system. Cycle shift operation can change the values of the pixels efficiently. The proposed cryptosystem decreases the volume of data to be transmitted and simplifies the keys distribution simultaneously as a nonlinear encryption system. Simulation results verify the validity and the reliability of the proposed algorithm with acceptable compression and security performance.

  3. 2D dose distribution images of a hybrid low field MRI-γ detector

    Abril, A.; Agulles-Pedrós, L.

    2016-07-01

    The proposed hybrid system is a combination of a low field MRI and dosimetric gel as a γ detector. The readout system is based on the polymerization process induced by the gel radiation. A gel dose map is obtained which represents the functional part of hybrid image alongside with the anatomical MRI one. Both images should be taken while the patient with a radiopharmaceutical is located inside the MRI system with a gel detector matrix. A relevant aspect of this proposal is that the dosimetric gel has never been used to acquire medical images. The results presented show the interaction of the 99mTc source with the dosimetric gel simulated in Geant4. The purpose was to obtain the planar γ 2D-image. The different source configurations are studied to explore the ability of the gel as radiation detector through the following parameters; resolution, shape definition and radio-pharmaceutical concentration.

  4. A 3D Feature Descriptor Recovered from a Single 2D Palmprint Image.

    Zheng, Qian; Kumar, Ajay; Pan, Gang

    2016-06-01

    Design and development of efficient and accurate feature descriptors is critical for the success of many computer vision applications. This paper proposes a new feature descriptor, referred to as DoN, for the 2D palmprint matching. The descriptor is extracted for each point on the palmprint. It is based on the ordinal measure which partially describes the difference of the neighboring points' normal vectors. DoN has at least two advantages: 1) it describes the 3D information, which is expected to be highly stable under commonly occurring illumination variations during contactless imaging; 2) the size of DoN for each point is only one bit, which is computationally simple to extract, easy to match, and efficient to storage. We show that such 3D information can be extracted from a single 2D palmprint image. The analysis for the effectiveness of ordinal measure for palmprint matching is also provided. Four publicly available 2D palmprint databases are used to evaluate the effectiveness of DoN, both for identification and the verification. Our method on all these databases achieves the state-of-the-art performance. PMID:27164564

  5. A faster method for 3D/2D medical image registration - a simulation study

    3D/2D patient-to-computed-tomography (CT) registration is a method to determine a transformation that maps two coordinate systems by comparing a projection image rendered from CT to a real projection image. Iterative variation of the CT's position between rendering steps finally leads to exact registration. Applications include exact patient positioning in radiation therapy, calibration of surgical robots, and pose estimation in computer-aided surgery. One of the problems associated with 3D/2D registration is the fact that finding a registration includes solving a minimization problem in six degrees of freedom (dof) in motion. This results in considerable time requirements since for each iteration step at least one volume rendering has to be computed. We show that by choosing an appropriate world coordinate system and by applying a 2D/2D registration method in each iteration step, the number of iterations can be grossly reduced from n6 to n5. Here, n is the number of discrete variations around a given coordinate. Depending on the configuration of the optimization algorithm, this reduces the total number of iterations necessary to at least 1/3 of it's original value. The method was implemented and extensively tested on simulated x-ray images of a tibia, a pelvis and a skull base. When using one projective image and a discrete full parameter space search for solving the optimization problem, average accuracy was found to be 1.0 ± 0.6 (deg.) and 4.1 ± 1.9 (mm) for a registration in six parameters, and 1.0 ± 0.7 (deg.) and 4.2 ± 1.6 (mm) when using the 5 + 1 dof method described in this paper. Time requirements were reduced by a factor 3.1. We conclude that this hardware-independent optimization of 3D/2D registration is a step towards increasing the acceptance of this promising method for a wide number of clinical applications

  6. 2D Geoelectric Imaging of the Uneme-Nekhua Fracture Zone

    Muslim B. Aminu

    2014-01-01

    Full Text Available We have employed 2D geoelectric imaging to reveal the geometry and nature of a fracture zone in Uneme-Nekhua, southwestern Nigeria. The fracture zone is discernable from an outcropping rock scarp and appears to define the course of a seasonal stream. Data were acquired using the dipole-dipole survey array configuration with electrode separation of 6 m and a maximum dipole length of 60 m. Three traverses with lengths varying between 72 m and 120 m were laid orthogonal to the course of the seasonal stream. 2D geoelectric images of the subsurface along the profiles imaged a north-south trending fracture zone. This fracture zone appears to consist of two vertical fractures with more intense definition downstream. The eastern fracture is buried by recent sediment, while the western fracture appears to have experienced more recent tectonic activity as it appears to penetrate through the near surface. Perhaps at some point, deformation ceased on the eastern fracture and further strain was transferred to the western fracture. The fracture zone generally defines the course of the north-south seasonal stream with the exception of the downstream end where the fracture appears to have died out entirely. Two associated basement trenches lying parallel to and east of the fracture zone are also imaged.

  7. 3D/2D image registration using weighted histogram of gradient directions

    Ghafurian, Soheil; Hacihaliloglu, Ilker; Metaxas, Dimitris N.; Tan, Virak; Li, Kang

    2015-03-01

    Three dimensional (3D) to two dimensional (2D) image registration is crucial in many medical applications such as image-guided evaluation of musculoskeletal disorders. One of the key problems is to estimate the 3D CT- reconstructed bone model positions (translation and rotation) which maximize the similarity between the digitally reconstructed radiographs (DRRs) and the 2D fluoroscopic images using a registration method. This problem is computational-intensive due to a large search space and the complicated DRR generation process. Also, finding a similarity measure which converges to the global optimum instead of local optima adds to the challenge. To circumvent these issues, most existing registration methods need a manual initialization, which requires user interaction and is prone to human error. In this paper, we introduce a novel feature-based registration method using the weighted histogram of gradient directions of images. This method simplifies the computation by searching the parameter space (rotation and translation) sequentially rather than simultaneously. In our numeric simulation experiments, the proposed registration algorithm was able to achieve sub-millimeter and sub-degree accuracies. Moreover, our method is robust to the initial guess. It can tolerate up to +/-90°rotation offset from the global optimal solution, which minimizes the need for human interaction to initialize the algorithm.

  8. Volumetric synthetic aperture imaging with a piezoelectric 2D row-column probe

    Bouzari, Hamed; Engholm, Mathias; Christiansen, Thomas Lehrmann; Beers, Christopher; Lei, Anders; Stuart, Matthias Bo; Nikolov, Svetoslav Ivanov; Thomsen, Erik Vilain; Jensen, Jørgen Arendt

    2016-04-01

    The synthetic aperture (SA) technique can be used for achieving real-time volumetric ultrasound imaging using 2-D row-column addressed transducers. This paper investigates SA volumetric imaging performance of an in-house prototyped 3 MHz λ/2-pitch 62+62 element piezoelectric 2-D row-column addressed transducer array. Utilizing single element transmit events, a volume rate of 90 Hz down to 14 cm deep is achieved. Data are obtained using the experimental ultrasound scanner SARUS with a 70 MHz sampling frequency and beamformed using a delay-and-sum (DAS) approach. A signal-to-noise ratio of up to 32 dB is measured on the beamformed images of a tissue mimicking phantom with attenuation of 0.5 dB cm-1 MHz-1, from the surface of the probe to the penetration depth of 300λ. Measured lateral resolution as Full-Width-at-Half-Maximum (FWHM) is between 4λ and 10λ for 18% to 65% of the penetration depth from the surface of the probe. The averaged contrast is 13 dB for the same range. The imaging performance assessment results may represent a reference guide for possible applications of such an array in different medical fields.

  9. Designing of sparse 2D arrays for Lamb wave imaging using coarray concept

    Ambroziński, Łukasz, E-mail: ambrozin@agh.edu.pl; Stepinski, Tadeusz, E-mail: ambrozin@agh.edu.pl; Uhl, Tadeusz, E-mail: ambrozin@agh.edu.pl [AGH University of Science and technology, al. Mickiewicza 30, 30-059 Krakow (Poland)

    2015-03-31

    2D ultrasonic arrays have considerable application potential in Lamb wave based SHM systems, since they enable equivocal damage imaging and even in some cases wave-mode selection. Recently, it has been shown that the 2D arrays can be used in SHM applications in a synthetic focusing (SF) mode, which is much more effective than the classical phase array mode commonly used in NDT. The SF mode assumes a single element excitation of subsequent transmitters and off-line processing the acquired data. In the simplest implementation of the technique, only single multiplexed input and output channels are required, which results in significant hardware simplification. Application of the SF mode for 2D arrays creates additional degrees of freedom during the design of the array topology, which complicates the array design process, however, it enables sparse array designs with performance similar to that of the fully populated dense arrays. In this paper we present the coarray concept to facilitate synthesis process of an array’s aperture used in the multistatic synthetic focusing approach in Lamb waves-based imaging systems. In the coherent imaging, performed in the transmit/receive mode, the sum coarray is a morphological convolution of the transmit/receive sub-arrays. It can be calculated as the set of sums of the individual sub-arrays’ elements locations. The coarray framework will be presented here using a an example of a star-shaped array. The approach will be discussed in terms of beampatterns of the resulting imaging systems. Both simulated and experimental results will be included.

  10. Adaptive optofluidic lens(es) for switchable 2D and 3D imaging

    Huang, Hanyang; Wei, Kang; Zhao, Yi

    2016-03-01

    The stereoscopic image is often captured using dual cameras arranged side-by-side and optical path switching systems such as two separate solid lenses or biprism/mirrors. The miniaturization of the overall size of current stereoscopic devices down to several millimeters is at a sacrifice of further device size shrinkage. The limited light entry worsens the final image resolution and brightness. It is known that optofluidics offer good re-configurability for imaging systems. Leveraging this technique, we report a reconfigurable optofluidic system whose optical layout can be swapped between a singlet lens with 10 mm in diameter and a pair of binocular lenses with each lens of 3 mm in diameter for switchable two-dimensional (2D) and three-dimensional (3D) imaging. The singlet and the binoculars share the same optical path and the same imaging sensor. The singlet acquires a 3D image with better resolution and brightness, while the binoculars capture stereoscopic image pairs for 3D vision and depth perception. The focusing power tuning capability of the singlet and the binoculars enable image acquisition at varied object planes by adjusting the hydrostatic pressure across the lens membrane. The vari-focal singlet and binoculars thus work interchangeably and complementarily. The device is thus expected to have applications in robotic vision, stereoscopy, laparoendoscopy and miniaturized zoom lens system.

  11. An Approach to Face Recognition of 2-D Images Using Eigen Faces and PCA

    Annapurna Mishra

    2012-04-01

    Full Text Available Face detection is to find any face in a given image. Face recognition is a two-dimension problem used for detecting faces. The information contained in a face can be analysed automatically by this system like identity, gender, expression, age, race and pose. Normally face detection is done for a single image but it can also be extended for video stream. As the face images are normally upright, they can be described by a small set of 2-D characteristics views. Here the face images are projected to a feature space or face space to encode the variation between the known face images. The projected feature space or the face space can be defined as ‘eigenfaces’ and can be formed by eigenvectors of the face image set. The above process can be used to recognize a new face in unsupervised manner. This paper introduces an algorithm which is used for effective face recognition. It takes into consideration not only the face extraction but also the mathematical calculations which enable us to bring the image into a simple and technical form. It can also be implemented in real-time using data acquisition hardware and software interface with the face recognition systems. Face recognition can be applied to various domains including security systems, personal identification, image and film processing and human computer interaction.

  12. An Approach to Face Recognition of 2-D Images Using Eigen Faces and PCA

    Annapurna Mishra

    2012-05-01

    Full Text Available Face detection is to find any face in a given image. Face recognition is a two-dimension problem used fordetecting faces. The information contained in a face can be analysed automatically by this system likeidentity, gender, expression, age, race and pose. Normally face detection is done for a single image but itcan also be extended for video stream. As the face images are normally upright, they can be described by asmall set of 2-D characteristics views. Here the face images are projected to a feature space or face spaceto encode the variation between the known face images. The projected feature space or the face space canbe defined as ‘eigenfaces’ and can be formed by eigenvectors of the face image set. The above process canbe used to recognize a new face in unsupervised manner. This paper introduces an algorithm which is usedfor effective face recognition. It takes into consideration not only the face extraction but also themathematical calculations which enable us to bring the image into a simple and technical form. It can alsobe implemented in real-time using data acquisition hardware and software interface with the facerecognition systems. Face recognition can be applied to various domains including security systems,personal identification, image and film processing and human computer interaction.

  13. Three-dimensional imaging of acetabular dysplasia: diagnostic value and impact on surgical type classification

    Smet, Maria-Helena E-mail: marleen.smet@uz.kuleuven.ac.be; Marchal, Guy J.; Baert, Albert L.; Hoe, Lieven van; Cleynenbreugel, Johan van; Daniels, Hans; Molenaers, Guy; Moens, Pierre; Fabry, Guy

    2000-04-01

    Objective: To investigate the diagnostic value and the impact on surgical type classification of three-dimensional (3D) images for pre-surgical evaluation of dysplastic hips. Materials and methods: Three children with a different surgical type of hip dysplasia were investigated with helical computed tomography. For each patient, two-dimensional (2D) images, 3D, and a stereolithographic model of the dysplastic hip were generated. In two separate sessions, 40 medical observers independently analyzed the 2D images (session 1), the 2D and 3D images (session 2), and tried to identify the corresponding stereolithographic hip model. The influence of both image presentation (2D versus 3D images) and observer (degree of experience, radiologist versus orthopedic surgeon) were statistically analyzed. The SL model choice reflected the impact on surgical type classification. Results: Image presentation was a significant factor whereas the individual observer was not. Three-dimensional images scored significantly better than 2D images (P=0.0003). Three-dimensional imaging increased the correct surgical type classification by 35%. Conclusion: Three-dimensional images significantly improve the pre-surgical diagnostic assessment and surgical type classification of dysplastic hips.

  14. 2D and 3D visualization methods of endoscopic panoramic bladder images

    Behrens, Alexander; Heisterklaus, Iris; Müller, Yannick; Stehle, Thomas; Gross, Sebastian; Aach, Til

    2011-03-01

    While several mosaicking algorithms have been developed to compose endoscopic images of the internal urinary bladder wall into panoramic images, the quantitative evaluation of these output images in terms of geometrical distortions have often not been discussed. However, the visualization of the distortion level is highly desired for an objective image-based medical diagnosis. Thus, we present in this paper a method to create quality maps from the characteristics of transformation parameters, which were applied to the endoscopic images during the registration process of the mosaicking algorithm. For a global first view impression, the quality maps are laid over the panoramic image and highlight image regions in pseudo-colors according to their local distortions. This illustration supports then surgeons to identify geometrically distorted structures easily in the panoramic image, which allow more objective medical interpretations of tumor tissue in shape and size. Aside from introducing quality maps in 2-D, we also discuss a visualization method to map panoramic images onto a 3-D spherical bladder model. Reference points are manually selected by the surgeon in the panoramic image and the 3-D model. Then the panoramic image is mapped by the Hammer-Aitoff equal-area projection onto the 3-D surface using texture mapping. Finally the textured bladder model can be freely moved in a virtual environment for inspection. Using a two-hemisphere bladder representation, references between panoramic image regions and their corresponding space coordinates within the bladder model are reconstructed. This additional spatial 3-D information thus assists the surgeon in navigation, documentation, as well as surgical planning.

  15. Diagnostic performance of 3D TSE MRI versus 2D TSE MRI of the knee at 1.5 T, with prompt arthroscopic correlation, in the detection of meniscal and cruciate ligament tears*

    Chagas-Neto, Francisco Abaeté; Nogueira-Barbosa, Marcello Henrique; Lorenzato, Mário Müller; Salim, Rodrigo; Kfuri-Junior, Maurício; Crema, Michel Daoud

    2016-01-01

    Objective To compare the diagnostic performance of the three-dimensional turbo spin-echo (3D TSE) magnetic resonance imaging (MRI) technique with the performance of the standard two-dimensional turbo spin-echo (2D TSE) protocol at 1.5 T, in the detection of meniscal and ligament tears. Materials and Methods Thirty-eight patients were imaged twice, first with a standard multiplanar 2D TSE MR technique, and then with a 3D TSE technique, both in the same 1.5 T MRI scanner. The patients underwent knee arthroscopy within the first three days after the MRI. Using arthroscopy as the reference standard, we determined the diagnostic performance and agreement. Results For detecting anterior cruciate ligament tears, the 3D TSE and routine 2D TSE techniques showed similar values for sensitivity (93% and 93%, respectively) and specificity (80% and 85%, respectively). For detecting medial meniscal tears, the two techniques also had similar sensitivity (85% and 83%, respectively) and specificity (68% and 71%, respectively). In addition, for detecting lateral meniscal tears, the two techniques had similar sensitivity (58% and 54%, respectively) and specificity (82% and 92%, respectively). There was a substantial to almost perfect intraobserver and interobserver agreement when comparing the readings for both techniques. Conclusion The 3D TSE technique has a diagnostic performance similar to that of the routine 2D TSE protocol for detecting meniscal and anterior cruciate ligament tears at 1.5 T, with the advantage of faster acquisition. PMID:27141127

  16. X-ray imaging diagnostics for the inertial confinement fusion experiments

    We report on our continued development of the advanced x-ray plasma diagnostics based on spherically curved crystals. The diagnostics include x-ray spectroscopy with 1-D spatial resolution, 2-D monochromatic self-imaging and back-lighting, and can be extended to the x-ray collimating and 2-D absorption and emission spectroscopy. The system is currently used, but not limited to the diagnostics of the targets ablatively accelerated by the NRL Nike KrF laser. In cooperation with LLNL a comprehensive test of the NIF prototype spherically curved crystal assembly has been performed on the Nova laser. (authors)

  17. A DESCRIPTION METHOD FOR ARBITRARILY SHAPED AND SIZED GRANULES IN 2D IMAGE

    Chen Ken; Zhao Pan; Zhao Xuemei

    2009-01-01

    An alternative method is proposed in this letter for describing the arbitrary shape and size for granules in 2D image.After image binarization,the edge points on contour are detected,by which the centroid of the shape in question is sought using the moment calculation.Using Principal Com ponent Analysis (PCA),the major and minor diameters are computed.Based on the signature curve-fitting,the first-order derivative is taken so as to seek all the characteristic vertices.By con necting the vertices found,the simplified polygon is formed and utilized for shape and size descriptive purposes.The developed algorithm is run on two given real particle images,and the execution results indicate that the computed parameters can technically well describe the shape and size for the original particles,being able to provide a ready-to-use database for machine vision system to perform related data processing tasks.

  18. 2D SAFT technique to reduce grating lobes in volumetric imaging

    Martín, C. J.; Martínez, O.; Octavio, A.; Montero, F.; Ullate, L. G.

    2010-01-01

    Nowadays, ultrasonic imaging is widely accepted as a powerful tool for nondestructive evaluation in industrial and medical applications. Although its potential to provide volumetric images has been verified and there is a strong interest in the development of 3D system, it is an open question yet due to the large amount of required resources, the high volume of data under analysis, and the difficulty to design adequate sensors. This work is centered in the development of SAFT strategies for beamforming in 3D ultrasonic imaging systems based on a strong economy of resources in order to reduce complexity and cost, and improve the system portability. The use of synthetic aperture techniques (SAFT) to reduce the number of hardware channels has been a topic profusely studied in several application areas, such as radar, sonar or ultrasonic imaging. The conventional SAFT is based on the sequential activation, one by one, of the array elements in emission-reception. Once all the signals have been stored, the beamforming is applied in a post-processing stage, focusing every point in the image and correcting emission and reception simultaneously. SAFT images show higher lateral resolution than conventional phased array images, but unfortunately they also show grating lobes that reduce the contrast. Here we present a new SAFT technique for 2D arrays that eliminates the grating lobes making use of few resources. Thus, the technique requires no more than four reception channels in parallel for every emission. Experimental results are also presented to validate the simulations.

  19. A preliminary evaluation work on a 3D ultrasound imaging system for 2D array transducer

    Zhong, Xiaoli; Li, Xu; Yang, Jiali; Li, Chunyu; Song, Junjie; Ding, Mingyue; Yuchi, Ming

    2016-04-01

    This paper presents a preliminary evaluation work on a pre-designed 3-D ultrasound imaging system. The system mainly consists of four parts, a 7.5MHz, 24×24 2-D array transducer, the transmit/receive circuit, power supply, data acquisition and real-time imaging module. The row-column addressing scheme is adopted for the transducer fabrication, which greatly reduces the number of active channels . The element area of the transducer is 4.6mm by 4.6mm. Four kinds of tests were carried out to evaluate the imaging performance, including the penetration depth range, axial and lateral resolution, positioning accuracy and 3-D imaging frame rate. Several strong reflection metal objects , fixed in a water tank, were selected for the purpose of imaging due to a low signal-to-noise ratio of the transducer. The distance between the transducer and the tested objects , the thickness of aluminum, and the seam width of the aluminum sheet were measured by a calibrated micrometer to evaluate the penetration depth, the axial and lateral resolution, respectively. The experiment al results showed that the imaging penetration depth range was from 1.0cm to 6.2cm, the axial and lateral resolution were 0.32mm and 1.37mm respectively, the imaging speed was up to 27 frames per second and the positioning accuracy was 9.2%.

  20. GPU accelerated generation of digitally reconstructed radiographs for 2-D/3-D image registration.

    Dorgham, Osama M; Laycock, Stephen D; Fisher, Mark H

    2012-09-01

    Recent advances in programming languages for graphics processing units (GPUs) provide developers with a convenient way of implementing applications which can be executed on the CPU and GPU interchangeably. GPUs are becoming relatively cheap, powerful, and widely available hardware components, which can be used to perform intensive calculations. The last decade of hardware performance developments shows that GPU-based computation is progressing significantly faster than CPU-based computation, particularly if one considers the execution of highly parallelisable algorithms. Future predictions illustrate that this trend is likely to continue. In this paper, we introduce a way of accelerating 2-D/3-D image registration by developing a hybrid system which executes on the CPU and utilizes the GPU for parallelizing the generation of digitally reconstructed radiographs (DRRs). Based on the advancements of the GPU over the CPU, it is timely to exploit the benefits of many-core GPU technology by developing algorithms for DRR generation. Although some previous work has investigated the rendering of DRRs using the GPU, this paper investigates approximations which reduce the computational overhead while still maintaining a quality consistent with that needed for 2-D/3-D registration with sufficient accuracy to be clinically acceptable in certain applications of radiation oncology. Furthermore, by comparing implementations of 2-D/3-D registration on the CPU and GPU, we investigate current performance and propose an optimal framework for PC implementations addressing the rigid registration problem. Using this framework, we are able to render DRR images from a 256×256×133 CT volume in ~24 ms using an NVidia GeForce 8800 GTX and in ~2 ms using NVidia GeForce GTX 580. In addition to applications requiring fast automatic patient setup, these levels of performance suggest image-guided radiation therapy at video frame rates is technically feasible using relatively low cost PC

  1. A 2D eye gaze estimation system with low-resolution webcam images

    Kim Jin

    2011-01-01

    Full Text Available Abstract In this article, a low-cost system for 2D eye gaze estimation with low-resolution webcam images is presented. Two algorithms are proposed for this purpose, one for the eye-ball detection with stable approximate pupil-center and the other one for the eye movements' direction detection. Eyeball is detected using deformable angular integral search by minimum intensity (DAISMI algorithm. Deformable template-based 2D gaze estimation (DTBGE algorithm is employed as a noise filter for deciding the stable movement decisions. While DTBGE employs binary images, DAISMI employs gray-scale images. Right and left eye estimates are evaluated separately. DAISMI finds the stable approximate pupil-center location by calculating the mass-center of eyeball border vertices to be employed for initial deformable template alignment. DTBGE starts running with initial alignment and updates the template alignment with resulting eye movements and eyeball size frame by frame. The horizontal and vertical deviation of eye movements through eyeball size is considered as if it is directly proportional with the deviation of cursor movements in a certain screen size and resolution. The core advantage of the system is that it does not employ the real pupil-center as a reference point for gaze estimation which is more reliable against corneal reflection. Visual angle accuracy is used for the evaluation and benchmarking of the system. Effectiveness of the proposed system is presented and experimental results are shown.

  2. Application of Enhanced-2D-CWT in Topographic Images for Mapping Landslide Risk Areas

    Valenzuela, V V Vermehren; de Oliveira, H M

    2015-01-01

    There has been lately a number of catastrophic events of landslides and mudslides in the mountainous region of Rio de Janeiro, Brazil. Those were caused by intense rain in localities where there was unplanned occupation of slopes of hills and mountains. Thus, it became imperative creating an inventory of landslide risk areas in densely populated cities. This work presents a way of demarcating risk areas by using the bidimensional Continuous Wavelet Transform (2D-CWT) applied to high resolution topographic images of the mountainous region of Rio de Janeiro.

  3. Diagnostic imaging of child abuse

    Oguma, Eiji; Aihara, Toshinori [Saitama Children' s Medical Center, Iwatsuki (Japan)

    2002-04-01

    The major role of imaging in cases of suspected child abuse is to identify the physical injuries and to confirm the occurrence of abuse. In severely abused infants, the imaging findings may be the only evidence for a diagnosis of inflicted injury. Imaging may be the first clue to abuse in children seen with apparent other conditions and lead to appropriate measures to protect them from the risk of more serious injury. The radiologist must be familiar with imaging findings of inflicted injuries to fulfill these roles. (author)

  4. Diagnostic imaging of cardiac hypertrophy

    As imaging techniques for cardiac hypertrophy, the ultrasonic dimension gauze technique, echocardiography, ventriculography and the RI technique including emission RI tomography were outlined. (Chiba, N.)

  5. Diagnostic imaging of child abuse

    The major role of imaging in cases of suspected child abuse is to identify the physical injuries and to confirm the occurrence of abuse. In severely abused infants, the imaging findings may be the only evidence for a diagnosis of inflicted injury. Imaging may be the first clue to abuse in children seen with apparent other conditions and lead to appropriate measures to protect them from the risk of more serious injury. The radiologist must be familiar with imaging findings of inflicted injuries to fulfill these roles. (author)

  6. Child abuse. Diagnostic imaging of skeletal injuries

    Diagnostic imaging, besides medical history and clinical examination, is a major component in assessment of cases of suspected physical child abuse. Performance of proper imaging technique, and knowledge of specific injury patterns is required for accurate image interpretation by the radiologist, and serves protection of the child in case of proven abuse. On the other side, it is essential to protect the family in unjustified accusations. The reader will be familiarised with essentials of the topic 'Physical child abuse', in order to be able to correctly assess quality, completeness, and results of X-ray films. Moreover, opportunities and limitations of alternative diagnostic modalities will be discussed. (orig.)

  7. 2D aperture synthesis for Lamb wave imaging using co-arrays

    Ambrozinski, Lukasz; Stepinski, Tadeusz; Uhl, Tadeusz

    2014-03-01

    2D ultrasonic arrays in Lamb wave based SHM systems can operate in the phased array (PA) or synthetic focusing (SF) mode. In the real-time PA approach, multiple electronically delayed signals excite transmitting elements to form the desired wave-front, whereas receiving elements are used to sense scattered waves. Due to that, the PA mode requires multi channeled hardware and multiple excitations at numerous azimuths to scan the inspected region of interest. To the contrary, the SF mode, assumes a single element excitation of subsequent transmitters and off-line processing of the acquired data. In the simplest implementation of the SF technique, a single multiplexed input and output channels are required, which results in significant hardware simplification. Performance of a 2D imaging array depends on many parameters, such as, its topology, number of its transducers and their spacing in terms of wavelength as well as the type of weighting function (apodization). Moreover, it is possible to use sparse arrays, which means that not all array elements are used for transmitting and/ or receiving. In this paper the co-array concept is applied to facilitate the synthesis process of an array's aperture used in the multistatic synthetic focusing approach in Lamb waves-based imaging systems. In the coherent imaging, performed in the transmit/receive mode, the sum co-array is a morphological convolution of the transmit/receive sub-arrays. It can be calculated as the set of sums of the individual elements' locations in the sub-arrays used for imaging. The coarray framework will be presented here using two different array topologies, aID uniform linear array and a cross-shaped array that will result in a square coarray. The approach will be discussed in terms of array patterns and beam patterns of the resulting imaging systems. Both, theoretical and experimental results will be given.

  8. Hybrid Feature Point Based Registration of 2D Abdominal CT Images

    Asmita A. Moghe

    2010-07-01

    Full Text Available Liver lesions like abscess, cirrhosis, metastases etc usually appear globular with gray levels differing remarkably from that of the surrounding liver region but the boundaries of these lesions are poorly defined and give an approximate picture of the extent of invasion of the lesion into surrounding regions. Choice of feature points and their matching in the images under consideration is crucial and image dependent. This leads to variations in registration methods. The objective of the proposed technique is to enhance registration for such abdominal CT images with the use of invariant points lying on the boundaries of lesions and the lesion centroids as the feature points. This paper uses a combination of hull points and centroids as feature points to register the images and compares results with those obtained by registration using only centroids as feature points. The outer margins of lesions become more sharply defined which helps in improving diagnostic accuracy.

  9. Managing digitally formatted diagnostic image data

    Diagnostic radiologists are very comfortable using analog radiographic film and interpreting its recorded images. To improve patient care, the radiologist has sought the finest quality radiographic film for use with the best radiographic imaging systems. The proper choice and use of x-ray tubes, generators, film-screen combinations, and contrast media has occupied the professional attention of the radiologist since the inception of radiology. Image quality can be significantly improved with digitally formatted diagnostic imaging systems by providing dynamic ranges in excess of those possible with analog x-ray films. In a CT scanner, the digital acquisition and reconstruction system can obtain a dynamic range (contrast resolution) of 10,000 to 1. Digital subtraction angiography systems achieve 10-bit dynamic ranges for each of the acquired television frames. Increases in the dynamic ranges of the various imaging modalities have been coupled with improved spatial resolution. A digitally formatted image is a two-dimensional, numerical array of discrete image elements. Each picture element is called a pixel. Each pixel has a discrete size. Figure 15.1 illustrates a digitally formatted image depicting the spatial resolution, array size, and quantization or numerical range of the pixel values. Currently, 512 x 512 image arrays are standard. Development of 1024 x 1024 digital arrays are underway. Significant improvements have also been achieved in the rates at which digital diagnostic imaging data can be acquired, manipulated, and archived

  10. The neutron imaging diagnostic at NIF (invited)

    A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of Inertial Confinement Fusion (ICF) implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6–12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.

  11. The neutron imaging diagnostic at NIF (invited)

    Merrill, F. E.; Clark, D. D.; Danly, C. R.; Drury, O. B.; Fatherley, V. E.; Gallegos, R.; Grim, G. P.; Guler, N.; Loomis, E. N.; Martinson, D. D.; Mares, D.; Morley, D. J.; Morgan, G. L.; Oertel, J. A.; Tregillis, I. L.; Volegov, P. L.; Wilde, C. H.; Wilson, D. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Bower, D.; Dzenitis, J. M. [Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2012-10-15

    A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of Inertial Confinement Fusion (ICF) implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.

  12. The Neutron Imaging Diagnostic at NIF

    Merrill, F E; Buckles, R; Clark, D; Danly, C R; Drury, O B; Dzenitis, J M; Fatherly, V E; Fittinghoff, D N; Gallegos, R; Grim, G P; Guler, N; Loomis, E N; Lutz, S; Malone, R M; Martinson, D D; Mares, D; Morley, D J; Morgan, G L; Oertel, J A; Tregillis, I L; Volegov, P L; Weiss, P B; Wilde, C H

    2012-10-01

    A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of ICF implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.

  13. Aorto-caval fistula: diagnosis by CT with 2D and 3D reformations spiral; Fistule aorto-cave diagnostic par scanographie spiralee avec reconstructions 2D et 3D

    Guth, S.; Clouet, Pl.; Zollner, G.; Rimmelin, A.; Dietemann, J.L.; Chakfe, N. [Hopital de Hautepierre, 67 - Strasbourg (France)

    1997-11-01

    We report a case of arteriovenous fistula due to spontaneous rupture of an aortic aneurysm into the inferior vena cava. This is a rare complication of atheromatous aneurysm, often difficult to diagnose as the clinical presentation may be obscure. Although aortography is the reference diagnostic investigation, spiral CT acquisition with 3D and 2D reformation allowed visualization of the arteriovenous communication and provided an accurate diagnosis. (authors)

  14. Clinics in diagnostic imaging. 145.

    Bosco, Jerome Irai Ezhil; Low, Albert S C; Tan, Damien M Y; Peh, Wilfred C G

    2013-04-01

    A 63-year-old man presented with painless jaundice, loss of appetite and significant weight loss. Cross-sectional imaging showed a diffusely enlarged pancreas, with no significant fat stranding and a hypodense rim on computed tomography, which appeared hypointense on T2-weighted magnetic resonance imaging. There was a narrowed pancreatic duct and features of common bile duct narrowing in the region of the pancreatic head. However, there was no obvious mass seen in the pancreatic head region. These features were classical of autoimmune pancreatitis with diffuse involvement of the gland. Laboratory investigation showed abnormal liver function and the classical sign of raised immunoglobulin G class 4 antibodies. The patient showed dramatic response to high-dose steroids, with resolution of both the laboratory and imaging abnormalities within one month. We discuss the classical imaging features of Type 1 autoimmune pancreatitis, an uncommon condition that needs to be differentiated from pancreatic malignancy. PMID:23624453

  15. Evaluation of osseointegration using image analysis and visualization of 2D and 3D image data

    Sarve, Hamid

    2011-01-01

    Computerized image analysis, the discipline of using computers to automatically extract information from digital images, is a powerful tool for automating time consuming analysis tasks. In this thesis, image analysis and visualization methods are developed to facilitate the evaluation of osseointegration, i.e., the biological integration of a load-carrying implant in living bone. Adequate osseointegration is essential in patients who are in need of implant treatment. New implant types, w...

  16. Constructing a Database from Multiple 2D Images for Camera Pose Estimation and Robot Localization

    Wolf, Michael; Ansar, Adnan I.; Brennan, Shane; Clouse, Daniel S.; Padgett, Curtis W.

    2012-01-01

    The LMDB (Landmark Database) Builder software identifies persistent image features (landmarks) in a scene viewed multiple times and precisely estimates the landmarks 3D world positions. The software receives as input multiple 2D images of approximately the same scene, along with an initial guess of the camera poses for each image, and a table of features matched pair-wise in each frame. LMDB Builder aggregates landmarks across an arbitrarily large collection of frames with matched features. Range data from stereo vision processing can also be passed to improve the initial guess of the 3D point estimates. The LMDB Builder aggregates feature lists across all frames, manages the process to promote selected features to landmarks, and iteratively calculates the 3D landmark positions using the current camera pose estimations (via an optimal ray projection method), and then improves the camera pose estimates using the 3D landmark positions. Finally, it extracts image patches for each landmark from auto-selected key frames and constructs the landmark database. The landmark database can then be used to estimate future camera poses (and therefore localize a robotic vehicle that may be carrying the cameras) by matching current imagery to landmark database image patches and using the known 3D landmark positions to estimate the current pose.

  17. Imaging methods for knee-joint diagnostics

    Imaging methods are essential tools for orthopedic diagnostics. For examination of knee-joint disorder, X-ray radiography in four planes is a standard task. Special diagnostic methods are available and can be selected according to the case, and sonography is a method very likely to gain significance. In case of suspected fracture, conventional tomography is the method of choice, although arthroscopy is discussed in this context as a primary examination. CT or NMR imaging are indicated for evaluation of tumors near the knee joint, and latest results show that magnetic resonance tomography is useful for examination of the cruciate ligaments or the cartilage, and CT for imaging of the menisci. CT assisted arthrography for sliding path and cartilage analysis already is an established method for diagnostic evaluation of the chondropathia patellae. (orig./MG)

  18. Rotationally symmetric triangulation sensor with integrated object imaging using only one 2D detector

    Eckstein, Johannes; Lei, Wang; Becker, Jonathan; Jun, Gao; Ott, Peter

    2006-04-01

    In this paper a distance measurement sensor is introduced, equipped with two integrated optical systems, the first one for rotationally symmetric triangulation and the second one for imaging the object while using only one 2D detector for both purposes. Rotationally symmetric triangulation, introduced in [1], eliminates some disadvantages of classical triangulation sensors, especially at steps or strong curvatures of the object, wherefore the measurement result depends not any longer on the angular orientation of the sensor. This is achieved by imaging the scattered light from an illuminated object point to a centered and sharp ring on a low cost area detector. The diameter of the ring is proportional to the distance of the object. The optical system consists of two off axis aspheric reflecting surfaces. This system allows for integrating a second optical system in order to capture images of the object at the same 2D detector. A mock-up was realized for the first time which consists of the reflecting optics for triangulation manufactured by diamond turning. A commercially available appropriate small lens system for imaging was mechanically integrated in the reflecting optics. Alternatively, some designs of retrofocus lens system for larger field of views were investigated. The optical designs allow overlying the image of the object and the ring for distance measurement in the same plane. In this plane a CCD detector is mounted, centered to the optical axis for both channels. A fast algorithm for the evaluation of the ring is implemented. The characteristics, i.e. the ring diameter versus object distance shows very linear behavior. For illumination of the object point for distance measurement, the beam of a red laser diode system is reflected by a wavelength bandpath filter on the axis of the optical system in. Additionally, the surface of the object is illuminated by LED's in the green spectrum. The LED's are located on the outside rim of the reflecting optics. The

  19. Interobserver, intraobserver and intrapatient reliability scores of myocardial strain imaging with 2-d echocardiography in patients treated with anthracyclines.

    Mavinkurve-Groothuis, A.M.C.; Weijers, G.; Groot-Loonen, J.J.; Pourier, M.S.; Feuth, A.B.; Korte, C.L. de; Hoogerbrugge, P.M.; Kapusta, L.

    2009-01-01

    Myocardial strain imaging with 2-D echocardiography is a relatively new noninvasive method to assess myocardial deformation. To determine the interobserver, intraobserver and intrapatient reliability scores, we evaluated myocardial strain measurements of 10 asymptomatic survivors of childhood cancer

  20. 3D interfractional patient position verification using 2D-3D registration of orthogonal images

    Reproducible positioning of the patient during fractionated external beam radiation therapy is imperative to ensure that the delivered dose distribution matches the planned one. In this paper, we expand on a 2D-3D image registration method to verify a patient's setup in three dimensions (rotations and translations) using orthogonal portal images and megavoltage digitally reconstructed radiographs (MDRRs) derived from CT data. The accuracy of 2D-3D registration was improved by employing additional image preprocessing steps and a parabolic fit to interpolate the parameter space of the cost function utilized for registration. Using a humanoid phantom, precision for registration of three-dimensional translations was found to be better than 0.5 mm (1 s.d.) for any axis when no rotations were present. Three-dimensional rotations about any axis were registered with a precision of better than 0.2 deg. (1 s.d.) when no translations were present. Combined rotations and translations of up to 4 deg. and 15 mm were registered with 0.4 deg. and 0.7 mm accuracy for each axis. The influence of setup translations on registration of rotations and vice versa was also investigated and mostly agrees with a simple geometric model. Additionally, the dependence of registration accuracy on three cost functions, angular spacing between MDRRs, pixel size, and field-of-view, was examined. Best results were achieved by mutual information using 0.5 deg. angular spacing and a 10x10 cm2 field-of-view with 140x140 pixels. Approximating patient motion as rigid transformation, the registration method is applied to two treatment plans and the patients' setup errors are determined. Their magnitude was found to be ≤6.1 mm and ≤2.7 deg. for any axis in all of the six fractions measured for each treatment plan

  1. Advanced image-retrieving method for diagnostic image terminal

    Currently, various image terminals are being considered. However, most do not have the required capabilities for image retrieval for diagnostic use. For the purpose of a diagnosis or a conference by radiologists, the following three basic retrieval functions are indispensable. First is a key-based retrieval that identifies the required images by a key combination. Second is an image-based retrieval. The required image is selected by observing a range of abstract images displayed on the terminal. Third is a similar image retrieval that automatically searches the images having similar diagnostic findings in the database. These functions are developed by integrating relational database technology, image processing techniques, and high-speed similarity detection algorithms

  2. Highly-Automatic MI Based Multiple 2D/3D Image Registration Using Self-initialized Geodesic Feature Correspondences

    Zheng, Hongwei; Cleju, Ioan; Saupe, Dietmar

    2010-01-01

    Intensity based registration methods, such as the mutual information (MI), do not commonly consider the spatial geometric information and the initial correspondences are uncertainty. In this paper, we present a novel approach for achieving highly-automatic 2D/3D image registration integrating the advantages from both entropy MI and spatial geometric features correspondence methods. Inspired by the scale space theory, we project the surfaces on a 3D model to 2D normal image spaces provided tha...

  3. Assessment of liver fibrosis with 2-D shear wave elastography in comparison to transient elastography and acoustic radiation force impulse imaging in patients with chronic liver disease.

    Gerber, Ludmila; Kasper, Daniela; Fitting, Daniel; Knop, Viola; Vermehren, Annika; Sprinzl, Kathrin; Hansmann, Martin L; Herrmann, Eva; Bojunga, Joerg; Albert, Joerg; Sarrazin, Christoph; Zeuzem, Stefan; Friedrich-Rust, Mireen

    2015-09-01

    Two-dimensional shear wave elastography (2-D SWE) is an ultrasound-based elastography method integrated into a conventional ultrasound machine. It can evaluate larger regions of interest and, therefore, might be better at determining the overall fibrosis distribution. The aim of this prospective study was to compare 2-D SWE with the two best evaluated liver elastography methods, transient elastography and acoustic radiation force impulse (point SWE using acoustic radiation force impulse) imaging, in the same population group. The study included 132 patients with chronic hepatopathies, in which liver stiffness was evaluated using transient elastography, acoustic radiation force impulse imaging and 2-D SWE. The reference methods were liver biopsy for the assessment of liver fibrosis (n = 101) and magnetic resonance imaging/computed tomography for the diagnosis of liver cirrhosis (n = 31). No significant difference in diagnostic accuracy, assessed as the area under the receiver operating characteristic curve (AUROC), was found between the three elastography methods (2-D SWE, transient elastography, acoustic radiation force impulse imaging) for the diagnosis of significant and advanced fibrosis and liver cirrhosis in the "per protocol" (AUROCs for fibrosis stages ≥2: 0.90, 0.95 and 0.91; for fibrosis stage [F] ≥3: 0.93, 0.95 and 0.94; for F = 4: 0.92, 0.96 and 0.92) and "intention to diagnose" cohort (AUROCs for F ≥2: 0.87, 0.92 and 0.91; for F ≥3: 0.91, 0.93 and 0.94; for F = 4: 0.88, 0.90 and 0.89). Therefore, 2-D SWE, ARFI imaging and transient elastography seem to be comparably good methods for non-invasive assessment of liver fibrosis. PMID:26116161

  4. Diagnostic imaging of lipoma arborescens

    Objective. The imaging characteristics of lipoma arborescens using plain radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) are described. Design and patients. Five patients with a diagnosis of lipoma arborescens are presented. Three had monoarticular involvement of the knee joint. In the remaining two patients both knees and both hips, respectively, were affected. All patients were examined using plain radiographs and MRI. CT was employed in two cases. Results and conclusions. A conclusive diagnosis with exclusion of other synovial pathologies having similar clinical and radiological behaviour can be achieved on the basis of the MRI characteristics of lipoma arborescens. The aetiology of lipoma arborescens remains unknown, but its association with previous pathology of the affected joints in all our patients supports the theory of a non-neoplastic reactive process involving the synovial membrane. (orig.)

  5. Diagnostic imaging in neonatal stroke

    A cerebral artery infarction is an important differential diagnosis in the newborn with neurological abnormalities. Based on clinical data, its incidence is estimated to be 1 in 4000 newborns. Since the course is often subclinical, the true incidence is probably higher. Diagnosis: Cerebral ultrasound and Doppler sonography as readily available screening tools play a central role in the initial diagnosis of neonatal cerebral infarction. Definitive diagnosis is made by computed tomography or magnetic resonance imaging. Beside symptomatic anticonvulsive therapy, treatment aims at the prevention of secondary ischemic injury. Discussion: Three term infants with different clinical courses of neonatal stroke are presented to sensitize the clinician and the radiologist for this probably underdiagnosed entity. The role of imaging modalities in the diagnosis and follow-up of neonatal cerebral infarction is discussed. (orig.)

  6. Neuroblastoma: diagnostic imaging and staging

    Results of computed tomography (CT), scintigraphy, excretory urography, and other imaging tests used to diagnose and stage 38 cases of neuroblastoma prior to treatment were reviewed. Findings of these examinations were correlated with clinical data, laboratory data, results of biopsy, and surgical findings. CT was the most sensitive single test (100%) for the detection and delineation of the primary tumor. Calcifications that suggested the histologic diagnosis of neuroblastoma were present in 79% of the cases. Rim calcifications, the most specific pattern for neuroblastoma, were identified in 29% of all cases. CT alone accurately staged 82% of cases; when complemented by bone marrow biopsy, staging accuracy was 97%. CT alone was more accurate than any combination of imaging tests that excluded CT. An algorithm using CT is presented for the diagnosis and staging of neuroblastoma at reduced cost and with increased efficiency

  7. Clinics in diagnostic imaging (166)

    Goh, Lin Wah; Chinchure, Dinesh; Lim, Tze Chwan

    2016-01-01

    A 68-year-old woman with poorly controlled diabetes mellitus presented to the emergency department with choreoathetoid movements affecting the upper and lower left limbs. Computed tomography of the brain did not show any intracranial abnormalities. However, subsequent magnetic resonance (MR) imaging of the brain revealed an increased T1 signal in the right basal ganglia, raising the suspicion of nonketotic hyperglycaemic chorea-hemiballismus. Management consisted of adjusting her insulin dose...

  8. Diagnostic, treatment, and surgical imaging in epilepsy.

    Nagae, Lidia Mayumi; Lall, Neil; Dahmoush, Hisham; Nyberg, Eric; Mirsky, David; Drees, Cornelia; Honce, Justin M

    2016-01-01

    Dedicated epilepsy centers are growing in hospitals throughout the USA and abroad, with a continuously increasing role of imaging in multidisciplinary meetings. Imaging is paramount in diagnosis, treatment, and surgical decision-making in lesional and nonlesional epileptic disease. Besides being up-to-date with technical developments in imaging that may make an impact in patient care, familiarity with clinical and surgical aspects of epilepsy is fundamental to better understanding of patient management. The present article intends to revisit diagnostic, therapeutic, and surgical imaging in epilepsy. Finally, with the increase in frequency of epilepsy management-related procedures and their hardware, MRI safety issues are discussed. PMID:27317207

  9. Contributions in compression of 3D medical images and 2D images; Contributions en compression d'images medicales 3D et d'images naturelles 2D

    Gaudeau, Y

    2006-12-15

    The huge amounts of volumetric data generated by current medical imaging techniques in the context of an increasing demand for long term archiving solutions, as well as the rapid development of distant radiology make the use of compression inevitable. Indeed, if the medical community has sided until now with compression without losses, most of applications suffer from compression ratios which are too low with this kind of compression. In this context, compression with acceptable losses could be the most appropriate answer. So, we propose a new loss coding scheme based on 3D (3 dimensional) Wavelet Transform and Dead Zone Lattice Vector Quantization 3D (DZLVQ) for medical images. Our algorithm has been evaluated on several computerized tomography (CT) and magnetic resonance image volumes. The main contribution of this work is the design of a multidimensional dead zone which enables to take into account correlations between neighbouring elementary volumes. At high compression ratios, we show that it can out-perform visually and numerically the best existing methods. These promising results are confirmed on head CT by two medical patricians. The second contribution of this document assesses the effect with-loss image compression on CAD (Computer-Aided Decision) detection performance of solid lung nodules. This work on 120 significant lungs images shows that detection did not suffer until 48:1 compression and still was robust at 96:1. The last contribution consists in the complexity reduction of our compression scheme. The first allocation dedicated to 2D DZLVQ uses an exponential of the rate-distortion (R-D) functions. The second allocation for 2D and 3D medical images is based on block statistical model to estimate the R-D curves. These R-D models are based on the joint distribution of wavelet vectors using a multidimensional mixture of generalized Gaussian (MMGG) densities. (author)

  10. Diagnostic imaging of abdominal aortic aneurysms

    The survey explains the available methods for diagnostic imaging of aortic aneurysms, i.e. the conventional methods of ultrasonography and intra-arterial angiography as well as the modern tomographic and image processing techniques such as CT, DSA, and MRT. The various methods are briefly discussed with respect to their sensitivity and specificity. The authors expect that MRI will become the modality of choice, due to absence of radiation exposure of the patients

  11. Automatic ultrasound image enhancement for 2D semi-automatic breast-lesion segmentation

    Lu, Kongkuo; Hall, Christopher S.

    2014-03-01

    Breast cancer is the fastest growing cancer, accounting for 29%, of new cases in 2012, and second leading cause of cancer death among women in the United States and worldwide. Ultrasound (US) has been used as an indispensable tool for breast cancer detection/diagnosis and treatment. In computer-aided assistance, lesion segmentation is a preliminary but vital step, but the task is quite challenging in US images, due to imaging artifacts that complicate detection and measurement of the suspect lesions. The lesions usually present with poor boundary features and vary significantly in size, shape, and intensity distribution between cases. Automatic methods are highly application dependent while manual tracing methods are extremely time consuming and have a great deal of intra- and inter- observer variability. Semi-automatic approaches are designed to counterbalance the advantage and drawbacks of the automatic and manual methods. However, considerable user interaction might be necessary to ensure reasonable segmentation for a wide range of lesions. This work proposes an automatic enhancement approach to improve the boundary searching ability of the live wire method to reduce necessary user interaction while keeping the segmentation performance. Based on the results of segmentation of 50 2D breast lesions in US images, less user interaction is required to achieve desired accuracy, i.e. < 80%, when auto-enhancement is applied for live-wire segmentation.

  12. Advantages of digital imaging for radiological diagnostic

    The advantages and limitations of radiological digital images in comparison with analogic ones are analyzed. We discuss three main topics: acquisition, post-procedure manipulation, and visualization, archive and communication. Digital acquisition with computed radiology systems present a global sensitivity very close to conventional film for diagnostic purposes. However, flat panel digital systems seems to achieve some advantages in particular clinical situations. A critical issue is the radiation dose-reduction that can be accomplished without reducing image quality nor diagnostic exactitude. The post-procedure manipulation allows, particularly in multiplanar modalities like CT or MR, to extract all implicit diagnostic information in the images: Main procedures are multiplanar and three-dimensional reformations, dynamic acquisitions, functional studies and image fusion. The use of PACS for visualization, archive and communication of images, improves the effectiveness and the efficiency of the workflow, allows a more comfortable diagnosis for the radiologist and gives way to improvements in the communication of images, allowing tele consulting and the tele radiology. (Author) 6 refs

  13. Absorption and scattering 2-D volcano images from numerically calculated space-weighting functions

    Del Pezzo, Edoardo; Ibañez, Jesus; Prudencio, Janire; Bianco, Francesca; De Siena, Luca

    2016-08-01

    Short-period small magnitude seismograms mainly comprise scattered waves in the form of coda waves (the tail part of the seismogram, starting after S waves and ending when the noise prevails), spanning more than 70 per cent of the whole seismogram duration. Corresponding coda envelopes provide important information about the earth inhomogeneity, which can be stochastically modeled in terms of distribution of scatterers in a random medium. In suitable experimental conditions (i.e. high earth heterogeneity), either the two parameters describing heterogeneity (scattering coefficient), intrinsic energy dissipation (coefficient of intrinsic attenuation) or a combination of them (extinction length and seismic albedo) can be used to image Earth structures. Once a set of such parameter couples has been measured in a given area and for a number of sources and receivers, imaging their space distribution with standard methods is straightforward. However, as for finite-frequency and full-waveform tomography, the essential problem for a correct imaging is the determination of the weighting function describing the spatial sensitivity of observable data to scattering and absorption anomalies. Due to the nature of coda waves, the measured parameter couple can be seen as a weighted space average of the real parameters characterizing the rock volumes illuminated by the scattered waves. This paper uses the Monte Carlo numerical solution of the Energy Transport Equation to find approximate but realistic 2-D space-weighting functions for coda waves. Separate images for scattering and absorption based on these sensitivity functions are then compared with those obtained with commonly used sensitivity functions in an application to data from an active seismic experiment carried out at Deception Island (Antarctica). Results show that these novel functions are based on a reliable and physically grounded method to image magnitude and shape of scattering and absorption anomalies. Their

  14. 2-D traveltime and waveform inversion for improved seismic imaging: Naga Thrust and Fold Belt, India

    Jaiswal, Priyank; Zelt, Colin A.; Bally, Albert W.; Dasgupta, Rahul

    2008-05-01

    Exploration along the Naga Thrust and Fold Belt in the Assam province of Northeast India encounters geological as well as logistic challenges. Drilling for hydrocarbons, traditionally guided by surface manifestations of the Naga thrust fault, faces additional challenges in the northeast where the thrust fault gradually deepens leaving subtle surface expressions. In such an area, multichannel 2-D seismic data were collected along a line perpendicular to the trend of the thrust belt. The data have a moderate signal-to-noise ratio and suffer from ground roll and other acquisition-related noise. In addition to data quality, the complex geology of the thrust belt limits the ability of conventional seismic processing to yield a reliable velocity model which in turn leads to poor subsurface image. In this paper, we demonstrate the application of traveltime and waveform inversion as supplements to conventional seismic imaging and interpretation processes. Both traveltime and waveform inversion utilize the first arrivals that are typically discarded during conventional seismic processing. As a first step, a smooth velocity model with long wavelength characteristics of the subsurface is estimated through inversion of the first-arrival traveltimes. This velocity model is then used to obtain a Kirchhoff pre-stack depth-migrated image which in turn is used for the interpretation of the fault. Waveform inversion is applied to the central part of the seismic line to a depth of ~1 km where the quality of the migrated image is poor. Waveform inversion is performed in the frequency domain over a series of iterations, proceeding from low to high frequency (11-19 Hz) using the velocity model from traveltime inversion as the starting model. In the end, the pre-stack depth-migrated image and the waveform inversion model are jointly interpreted. This study demonstrates that a combination of traveltime and waveform inversion with Kirchhoff pre-stack depth migration is a promising approach

  15. Self-calibration of cone-beam CT geometry using 3D-2D image registration

    Ouadah, S.; Stayman, J. W.; Gang, G. J.; Ehtiati, T.; Siewerdsen, J. H.

    2016-04-01

    Robotic C-arms are capable of complex orbits that can increase field of view, reduce artifacts, improve image quality, and/or reduce dose; however, it can be challenging to obtain accurate, reproducible geometric calibration required for image reconstruction for such complex orbits. This work presents a method for geometric calibration for an arbitrary source-detector orbit by registering 2D projection data to a previously acquired 3D image. It also yields a method by which calibration of simple circular orbits can be improved. The registration uses a normalized gradient information similarity metric and the covariance matrix adaptation-evolution strategy optimizer for robustness against local minima and changes in image content. The resulting transformation provides a ‘self-calibration’ of system geometry. The algorithm was tested in phantom studies using both a cone-beam CT (CBCT) test-bench and a robotic C-arm (Artis Zeego, Siemens Healthcare) for circular and non-circular orbits. Self-calibration performance was evaluated in terms of the full-width at half-maximum (FWHM) of the point spread function in CBCT reconstructions, the reprojection error (RPE) of steel ball bearings placed on each phantom, and the overall quality and presence of artifacts in CBCT images. In all cases, self-calibration improved the FWHM—e.g. on the CBCT bench, FWHM  =  0.86 mm for conventional calibration compared to 0.65 mm for self-calibration (p  self-calibration (p  self-calibration, particularly about high-contrast, high-frequency objects (e.g. temporal bone air cells and a surgical needle). The results indicate that self-calibration can improve even upon systems with presumably accurate geometric calibration and is applicable to situations where conventional calibration is not feasible, such as complex non-circular CBCT orbits and systems with irreproducible source-detector trajectory.

  16. Web-based interactive 2D/3D medical image processing and visualization software.

    Mahmoudi, Seyyed Ehsan; Akhondi-Asl, Alireza; Rahmani, Roohollah; Faghih-Roohi, Shahrooz; Taimouri, Vahid; Sabouri, Ahmad; Soltanian-Zadeh, Hamid

    2010-05-01

    There are many medical image processing software tools available for research and diagnosis purposes. However, most of these tools are available only as local applications. This limits the accessibility of the software to a specific machine, and thus the data and processing power of that application are not available to other workstations. Further, there are operating system and processing power limitations which prevent such applications from running on every type of workstation. By developing web-based tools, it is possible for users to access the medical image processing functionalities wherever the internet is available. In this paper, we introduce a pure web-based, interactive, extendable, 2D and 3D medical image processing and visualization application that requires no client installation. Our software uses a four-layered design consisting of an algorithm layer, web-user-interface layer, server communication layer, and wrapper layer. To compete with extendibility of the current local medical image processing software, each layer is highly independent of other layers. A wide range of medical image preprocessing, registration, and segmentation methods are implemented using open source libraries. Desktop-like user interaction is provided by using AJAX technology in the web-user-interface. For the visualization functionality of the software, the VRML standard is used to provide 3D features over the web. Integration of these technologies has allowed implementation of our purely web-based software with high functionality without requiring powerful computational resources in the client side. The user-interface is designed such that the users can select appropriate parameters for practical research and clinical studies. PMID:20022133

  17. Clinics in diagnostic imaging (168)

    Lai, Yusheng Keefe; Mahmood, Rameysh Danovani

    2016-01-01

    A 16-year-old Chinese male patient presented with constipation lasting five days, colicky abdominal pain, lethargy, weakness and body aches. He was able to pass flatus. Abdominal radiography showed a distended stomach causing inferior displacement of the transverse colon. Computed tomography revealed a dilated oesophagus, stomach and duodenum up to its third portion, with a short aortomesenteric distance and narrow angle. There was also consolidation in the lungs bilaterally. Based on the constellation of clinical and imaging findings, a diagnosis of superior mesenteric artery syndrome complicated by aspiration pneumonia was made. The patient was subsequently started on intravenous hydration, nasogastric tube aspiration and antibiotics. Following stabilisation of his acute condition, a nasojejunal feeding tube was inserted and a feeding plan was implemented to promote weight gain. The clinical presentation, differentials, diagnosis and treatment of superior mesenteric artery syndrome are discussed. PMID:27212130

  18. Diagnostic imaging of the hand. 2. rev. and enl. ed.; Bildgebende Diagnostik der Hand

    Schmitt, R. [Herz- und Gefaessklinik, Bad Neustadt/Saale (Germany). Inst. fuer Diagnostische und Interkonventionelle Radiologie; Lanz, U. (eds.) [Klinik fuer Handchirurgie, Bad Neustadt/Saale (Germany)

    2004-07-01

    The second edition contains the following new features: Focus on cogenital, degenerative, inflammatory, tumourous, neurogenic and vascular diseases of the hands; new images of multiline spiral CT including 2D pictures and 3D reconstructions; new MRT images with examination protocols; synoptic presentation of all diseases according to their pathoanatomy, clinical symptoms, diagnostic imaging, differential diagnosis, therapeutic options; checklists for the doctor's everyday work. (orig.)

  19. Diagnostic Value of 64-slice CTA in Detection of Intracranial Aneurysm in Patients with SAH and Comparison of the CTA Results with 2D-DSA and Intraoperative Findings

    Ergun, Elif; Haberal, Murat; Koşar, Pınar; Yılmaz, Ali; Koşar, Uğur

    2011-01-01

    Objective: To prospectively evaluate the diagnostic value of 64-slice CTA in detecting intracranial aneurysms and to compare it with 2D-DSA and/or intra-operative findings. Material and Methods: 37 cases with SAH according to unenhanced cranial CT were included in the study. A 64-slice CTA was performed to all cases immediately after the nonenhanced cranial CT. DSA was performed in 24-48 hours following CTA. CT images were reviewed by two radiologists experienced in CT vascular imag...

  20. Diagnostic Value of 64-slice CTA in Detection of Intracranial Aneurysm in Patients with SAH and Comparison of the CTA Results with 2D-DSA and Intraoperative Findings

    Elif Ergun; Murat Haberal; Pınar Koşar; Ali Yılmaz; Uğur Koşar

    2011-01-01

    Objective: To prospectively evaluate the diagnostic value of 64-slice CTA in detecting intracranial aneurysms and to compare it with 2D-DSA and/or intra-operative findings.Material and Methods: 37 cases with SAH according to unenhanced cranial CT were included in the study. A 64-slice CTA was performed to all cases immediately after the nonenhanced cranial CT. DSA was performed in 24-48 hours following CTA. CT images were reviewed by two radiologists experienced in CT vascular imaging. The ...

  1. Development of 2D imaging of SXR plasma radiation by means of GEM detectors

    Chernyshova, M.; Czarski, T.; Jabłoński, S.; Kowalska-Strzeciwilk, E.; Poźniak, K.; Kasprowicz, G.; Zabołotny, W.; Wojeński, A.; Byszuk, A.; Burza, M.; Juszczyk, B.; Zienkiewicz, P.

    2014-11-01

    Presented 2D gaseous detector system has been developed and designed to provide energy resolved fast dynamic plasma radiation imaging in the soft X-Ray region with 0.1 kHz exposure frequency for online, made in real time, data acquisition (DAQ) mode. The detection structure is based on triple Gas Electron Multiplier (GEM) amplification structure followed by the pixel readout electrode. The efficiency of detecting unit was adjusted for the radiation energy region of tungsten in high-temperature plasma, the main candidate for the plasma facing material for future thermonuclear reactors. Here we present preliminary laboratory results and detector parameters obtained for the developed system. The operational characteristics and conditions of the detector were designed to work in the X-Ray range of 2-17 keV. The detector linearity was checked using the fluorescence lines of different elements and was found to be sufficient for good photon energy reconstruction. Images of two sources through various screens were performed with an X-Ray laboratory source and 55Fe source showing a good imaging capability. Finally offline stream-handling data acquisition mode has been developed for the detecting system with timing down to the ADC sampling frequency rate (~13 ns), up to 2.5 MHz of exposure frequency, which could pave the way to invaluable physics information about plasma dynamics due to very good time resolving ability. Here we present results of studied spatial resolution and imaging properties of the detector for conditions of laboratory moderate counting rates and high gain.

  2. Thymic hyperplasia - clinical course and imaging diagnostic

    The real thymic hyperplasia is benign disease sometimes simulating malignant tumours. The aim of this study is to analyse the clinical symptoms of real thymic hyperplasia and the results from imaging diagnostic based on our clinical material. Clinical material include 27 children, aged from two months to 15 years, admitted in department of thoracic surgery, for a period of 20 years (1985 - 2004). We retrospectively analyze the clinical signs and results from X-ray investigation, CT (Siemens Somatom DRG and Philips Secura) and echocardiography (Acuson TX, 5 and 7 MHz). We discuss the diagnostic value of different methods as well as typical and atypical findings. (authors)

  3. Digital Pulse Processor for ION Beam Microprobe and Micro X Ray Fluorescence 2-D and 3-D Imaging

    For a long time, the implementation of optimal pulse processing in nuclear spectrometry was only possible with analogue electronic components. Following the development of fast analogue to digital converters, field programmable gate arrays, and digital signal processors, it became feasible to digitize pulses after a preamplifier or phototube and process them in a real time. Therefore, digital electronics, which were limited to data storage and control of the acquisition process, became feasible for signal processing as well. This brought numerous benefits, such as better energy resolution with higher data throughput, reduced size, easier upgrading, the ability to automate adjustment and control of the complete data acquisition process, and self-diagnostic capability. In the same time, evaluation of the Electronic Design Automation tools and Intellectual Property industry enables a System-On-a-Chip paradigm on high density reprogrammable devices and allows new approach for system level design. Such a design provides opportunity for small laboratories to develop a compact 'all digital' customized instrumentation. In this work, we presented a design of FPGA IP core for high resolution, digital X ray, γ ray or particle spectrometry using high level FPGA design tool (Xilinx System Generator and Matlab - Simulink). The IP core has been used to build a simple low cost digital spectrometer (Spartan 3 FPGA based) and advance system for ion beam microprobe and X ray fluorescence 2-D and 3-D imaging. (Virtex 4 FPGA based). (author)

  4. Coronary arteries motion modeling on 2D x-ray images

    Gao, Yang; Sundar, Hari

    2012-02-01

    During interventional procedures, 3D imaging modalities like CT and MRI are not commonly used due to interference with the surgery and radiation exposure concerns. Therefore, real-time information is usually limited and building models of cardiac motion are difficult. In such case, vessel motion modeling based on 2-D angiography images become indispensable. Due to issues with existing vessel segmentation algorithms and the lack of contrast in occluded vessels, manual segmentation of certain branches is usually necessary. In addition, such occluded branches are the most important vessels during coronary interventions and obtaining motion models for these can greatly help in reducing the procedure time and radiation exposure. Segmenting different cardiac phases independently does not guarantee temporal consistency and is not efficient for occluded branches required manual segmentation. In this paper, we propose a coronary motion modeling system which extracts the coronary tree for every cardiac phase, maintaining the segmentation by tracking the coronary tree during the cardiac cycle. It is able to map every frame to the specific cardiac phase, thereby inferring the shape information of the coronary arteries using the model corresponding to its phase. Our experiments show that our motion modeling system can achieve promising results with real-time performance.

  5. 2D-sensitive hpxe gas proportional scintillation counter concept for nuclear medical imaging purposes

    The operation and first images of a high pressure xenon Gas Proportional Scintillation Counter (GPSC) are presented. In this setup, primary electrons produced by the absorption of X- or γ-rays in the gas medium drift to a region where the electric field is set to a value above the gas scintillation threshold, the scintillation region. The primary ionization signal is amplified through the electroluminescence produced along the electron drift in this region. A Micro-Hole and Strip Plate covered with CsI (CsI-MHSP) is used as the photosensor for the scintillation readout. The 2D capability of the CsI-MHSP photosensor is achieved by means of two orthogonal resistive lines interconnecting the strips patterned on both surfaces of the MHSP. The interaction position of the incident radiation can be obtained by determining the centroid of the photosensor area irradiated by the electroluminescence pulse. This centroid is obtained from the amplitude of the charge pulses collected at both ends of the resistive lines. Preliminary analyses of the first images obtained with electroluminescence signals at xenon pressures up to 3 bar indicate a position resolution capability of about 1.2 mm at 2.9 bar, for 59.6 keV γ-photons.

  6. FluoRender: An application of 2D image space methods for 3D and 4D confocal microscopy data visualization in neurobiology research

    Wan, Yong

    2012-02-01

    2D image space methods are processing methods applied after the volumetric data are projected and rendered into the 2D image space, such as 2D filtering, tone mapping and compositing. In the application domain of volume visualization, most 2D image space methods can be carried out more efficiently than their 3D counterparts. Most importantly, 2D image space methods can be used to enhance volume visualization quality when applied together with volume rendering methods. In this paper, we present and discuss the applications of a series of 2D image space methods as enhancements to confocal microscopy visualizations, including 2D tone mapping, 2D compositing, and 2D color mapping. These methods are easily integrated with our existing confocal visualization tool, FluoRender, and the outcome is a full-featured visualization system that meets neurobiologists\\' demands for qualitative analysis of confocal microscopy data. © 2012 IEEE.

  7. A novel technique for single-shot energy-resolved 2D X-ray imaging of plasmas relevant for the Inertial Confinement Fusion

    Labate, L.; Koester, P.; Levato, T.; Gizzi, L. A.

    2012-01-01

    A novel X-ray diagnostic of laser-fusion plasmas is described, allowing 2D monochromatic images of hot, dense plasmas to be obtained in any X-ray photon energy range, over a large domain, on a single-shot basis. The device (named Energy-encoded Pinhole Camera - EPiC) is based upon the use of an array of many pinholes coupled to a large area CCD camera operating in the single-photon mode. The available X-ray spectral domain is only limited by the Quantum Efficiency of scientific-grade X-ray CC...

  8. A GPU Simulation Tool for Training and Optimisation in 2D Digital X-Ray Imaging

    Gallio, Elena; Rampado, Osvaldo; Gianaria, Elena; Bianchi, Silvio Diego; Ropolo, Roberto

    2015-01-01

    Conventional radiology is performed by means of digital detectors, with various types of technology and different performance in terms of efficiency and image quality. Following the arrival of a new digital detector in a radiology department, all the staff involved should adapt the procedure parameters to the properties of the detector, in order to achieve an optimal result in terms of correct diagnostic information and minimum radiation risks for the patient. The aim of this study was to develop and validate a software capable of simulating a digital X-ray imaging system, using graphics processing unit computing. All radiological image components were implemented in this application: an X-ray tube with primary beam, a virtual patient, noise, scatter radiation, a grid and a digital detector. Three different digital detectors (two digital radiography and a computed radiography systems) were implemented. In order to validate the software, we carried out a quantitative comparison of geometrical and anthropomorphic phantom simulated images with those acquired. In terms of average pixel values, the maximum differences were below 15%, while the noise values were in agreement with a maximum difference of 20%. The relative trends of contrast to noise ratio versus beam energy and intensity were well simulated. Total calculation times were below 3 seconds for clinical images with pixel size of actual dimensions less than 0.2 mm. The application proved to be efficient and realistic. Short calculation times and the accuracy of the results obtained make this software a useful tool for training operators and dose optimisation studies. PMID:26545097

  9. Diagnostic imaging in pregraduate integrated curricula

    Pregraduate medical curricula are currently undergoing a reform process that is moving away from a traditional discipline-related structure and towards problem-based integrated forms of teaching. Imaging sciences, with their inherently technical advances, are specifically influenced by the effects of paradigm shifts in medical education. The teaching of diagnostic radiology should be based on the definition of three core competencies: in vivo visualization of normal and abnormal morphology and function, diagnostic reasoning, and interventional treatment. On the basis of these goals, adequate teaching methods and e-learning tools should be implemented by focusing on case-based teaching. Teaching materials used in the fields of normal anatomy, pathology, and clinical diagnosis may help diagnostic radiology to play a central role in modern pregraduate curricula. (orig.)

  10. Reproducing 2D breast mammography images with 3D printed phantoms

    Clark, Matthew; Ghammraoui, Bahaa; Badal, Andreu

    2016-03-01

    Mammography is currently the standard imaging modality used to screen women for breast abnormalities and, as a result, it is a tool of great importance for the early detection of breast cancer. Physical phantoms are commonly used as surrogates of breast tissue to evaluate some aspects of the performance of mammography systems. However, most phantoms do not reproduce the anatomic heterogeneity of real breasts. New fabrication technologies, such as 3D printing, have created the opportunity to build more complex, anatomically realistic breast phantoms that could potentially assist in the evaluation of mammography systems. The primary objective of this work is to present a simple, easily reproducible methodology to design and print 3D objects that replicate the attenuation profile observed in real 2D mammograms. The secondary objective is to evaluate the capabilities and limitations of the competing 3D printing technologies, and characterize the x-ray properties of the different materials they use. Printable phantoms can be created using the open-source code introduced in this work, which processes a raw mammography image to estimate the amount of x-ray attenuation at each pixel, and outputs a triangle mesh object that encodes the observed attenuation map. The conversion from the observed pixel gray value to a column of printed material with equivalent attenuation requires certain assumptions and knowledge of multiple imaging system parameters, such as x-ray energy spectrum, source-to-object distance, compressed breast thickness, and average breast material attenuation. A detailed description of the new software, a characterization of the printed materials using x-ray spectroscopy, and an evaluation of the realism of the sample printed phantoms are presented.

  11. Diagnostic performance on briefly presented mammographic images

    Mugglestone, Mark D.; Gale, Alastair G.; Cowley, Helen C.; Wilson, A. R. M.

    1995-04-01

    Previously an outline model of the radiological diagnostic process has been proposed which posits the importance of the initial glance at a medical image in helping to establish an appropriate diagnosis. As part of a long tern study of knowledge elicitation in mammography we examine the amount of information available to breast screening radiologists within the initial 'glance' at a mammogram. These data are compared to those from examining the same images normally. Overall, performance in a brief presentation was poorer than in normal viewing, as expected, but was also worse than found in comparable brief presentation studies using the chest radiograph. These results are discussed with regard to the inferences which can be made about the nature of mammographic knowledge which is utilized in the diagnostic process and how it is organized within the framework of a conceptual model.

  12. A radiographic imaging system based upon a 2-D silicon microstrip sensor

    Papanestis, A; Corrin, E; Raymond, M; Hall, G; Triantis, F A; Manthos, N; Evagelou, I; Van den Stelt, P; Tarrant, T; Speller, R D; Royle, G F

    2000-01-01

    A high resolution, direct-digital detector system based upon a 2-D silicon microstrip sensor has been designed, built and is undergoing evaluation for applications in dentistry and mammography. The sensor parameters and image requirements were selected using Monte Carlo simulations. Sensors selected for evaluation have a strip pitch of 50mum on the p-side and 80mum on the n-side. Front-end electronics and data acquisition are based on the APV6 chip and were adapted from systems used at CERN for high-energy physics experiments. The APV6 chip is not self-triggering so data acquisition is done at a fixed trigger rate. This paper describes the mammographic evaluation of the double sided microstrip sensor. Raw data correction procedures were implemented to remove the effects of dead strips and non-uniform response. Standard test objects (TORMAX) were used to determine limiting spatial resolution and detectability. MTFs were determined using the edge response. The results indicate that the spatial resolution of the...

  13. Automatic 2D segmentation of airways in thorax computed tomography images

    Introduction: much of the world population is affected by pulmonary diseases, such as the bronchial asthma, bronchitis and bronchiectasis. The bronchial diagnosis is based on the airways state. In this sense, the automatic segmentation of the airways in Computed Tomography (CT) scans is a critical step in the aid to diagnosis of these diseases. Methods: this paper evaluates algorithms for airway automatic segmentation, using Neural Network Multilayer Perceptron (MLP) and Lung Densities Analysis (LDA) for detecting airways, along with Region Growing (RG), Active Contour Method (ACM) Balloon and Topology Adaptive to segment them. Results: we obtained results in three stages: comparative analysis of the detection algorithms MLP and LDA, with a gold standard acquired by three physicians with expertise in CT imaging of the chest; comparative analysis of segmentation algorithms ACM Balloon, ACM Topology Adaptive, MLP and RG; and evaluation of possible combinations between segmentation and detection algorithms, resulting in the complete method for automatic segmentation of the airways in 2D. Conclusion: the low incidence of false negative and the significant reduction of false positive, results in similarity coefficient and sensitivity exceeding 91% and 87% respectively, for a combination of algorithms with satisfactory segmentation quality. (author)

  14. Craniosynostosis: prenatal diagnosis by 2D/3D ultrasound, magnetic resonance imaging and computed tomography.

    Helfer, Talita Micheletti; Peixoto, Alberto Borges; Tonni, Gabriele; Araujo Júnior, Edward

    2016-09-01

    Craniosynostosis is defined as the process of premature fusion of one or more of the cranial sutures. It is a common condition that occurs in about 1 to 2,000 live births. Craniosynostosis may be classified in primary or secondary. It is also classified as nonsyndromic or syndromic. According to suture commitment, craniosynostosis may affect a single suture or multiple sutures. There is a wide range of syndromes involving craniosynostosis and the most common are Apert, Pffeifer, Crouzon, Shaethre-Chotzen and Muenke syndromes. The underlying etiology of nonsyndromic craniosynostosis is unknown. Mutations in the fibroblast growth factor (FGF) signalling pathway play a crucial role in the etiology of craniosynostosis syndromes. Prenatal ultrasound`s detection rate of craniosynostosis is low. Nowadays, different methods can be applied for prenatal diagnosis of craniosynostosis, such as two-dimensional (2D) and three-dimensional (3D) ultrasound, magnetic resonance imaging (MRI), computed tomography (CT) scan and, finally, molecular diagnosis. The presence of craniosynostosis may affect the birthing process. Fetuses with craniosynostosis also have higher rates of perinatal complications. In order to avoid the risks of untreated craniosynostosis, children are usually treated surgically soon after postnatal diagnosis. PMID:27622416

  15. Determining ice water content from 2D crystal images in convective cloud systems

    Leroy, Delphine; Coutris, Pierre; Fontaine, Emmanuel; Schwarzenboeck, Alfons; Strapp, J. Walter

    2016-04-01

    Cloud microphysical in-situ instrumentation measures bulk parameters like total water content (TWC) and/or derives particle size distributions (PSD) (utilizing optical spectrometers and optical array probes (OAP)). The goal of this work is to introduce a comprehensive methodology to compute TWC from OAP measurements, based on the dataset collected during recent HAIC (High Altitude Ice Crystals)/HIWC (High Ice Water Content) field campaigns. Indeed, the HAIC/HIWC field campaigns in Darwin (2014) and Cayenne (2015) provide a unique opportunity to explore the complex relationship between cloud particle mass and size in ice crystal environments. Numerous mesoscale convective systems (MCSs) were sampled with the French Falcon 20 research aircraft at different temperature levels from -10°C up to 50°C. The aircraft instrumentation included an IKP-2 (isokinetic probe) to get reliable measurements of TWC and the optical array probes 2D-S and PIP recording images over the entire ice crystal size range. Based on the known principle relating crystal mass and size with a power law (m=α•Dβ), Fontaine et al. (2014) performed extended 3D crystal simulations and thereby demonstrated that it is possible to estimate the value of the exponent β from OAP data, by analyzing the surface-size relationship for the 2D images as a function of time. Leroy et al. (2015) proposed an extended version of this method that produces estimates of β from the analysis of both the surface-size and perimeter-size relationships. Knowing the value of β, α then is deduced from the simultaneous IKP-2 TWC measurements for the entire HAIC/HIWC dataset. The statistical analysis of α and β values for the HAIC/HIWC dataset firstly shows that α is closely linked to β and that this link changes with temperature. From these trends, a generalized parameterization for α is proposed. Finally, the comparison with the initial IKP-2 measurements demonstrates that the method is able to predict TWC values

  16. Software for 3D diagnostic image reconstruction and analysis

    Recent advances in computer technologies have opened new frontiers in medical diagnostics. Interesting possibilities are the use of three-dimensional (3D) imaging and the combination of images from different modalities. Software prepared in our laboratories devoted to 3D image reconstruction and analysis from computed tomography and ultrasonography is presented. In developing our software it was assumed that it should be applicable in standard medical practice, i.e. it should work effectively with a PC. An additional feature is the possibility of combining 3D images from different modalities. The reconstruction and data processing can be conducted using a standard PC, so low investment costs result in the introduction of advanced and useful diagnostic possibilities. The program was tested on a PC using DICOM data from computed tomography and TIFF files obtained from a 3D ultrasound system. The results of the anthropomorphic phantom and patient data were taken into consideration. A new approach was used to achieve spatial correlation of two independently obtained 3D images. The method relies on the use of four pairs of markers within the regions under consideration. The user selects the markers manually and the computer calculates the transformations necessary for coupling the images. The main software feature is the possibility of 3D image reconstruction from a series of two-dimensional (2D) images. The reconstructed 3D image can be: (1) viewed with the most popular methods of 3D image viewing, (2) filtered and processed to improve image quality, (3) analyzed quantitatively (geometrical measurements), and (4) coupled with another, independently acquired 3D image. The reconstructed and processed 3D image can be stored at every stage of image processing. The overall software performance was good considering the relatively low costs of the hardware used and the huge data sets processed. The program can be freely used and tested (source code and program available at

  17. Eddy current imaging. Simplifying the direct problem. Analysis of a 2D case with formulations

    Eddy current non-destructive testing is used by EDF to detect faults affecting conductive objects such as steam generator tubes. A new technique, known as eddy current imaging, is being developed to facilitate diagnosis in this context. The first stage in this work, discussed in the present paper, consists in solving the direct problem. This entails determining the measurable quantities, on the basis of a thorough knowledge of the material considered. This was done by formulating the direct problem in terms of eddy currents in general 3D geometry context, applying distribution theory and Maxwell equations. Since no direct problem code was available we resorted to simplified situations. Taking care not to interfere with previous developments or those to be attempted in an inversion context, we studied the case of a flaw affecting a 2D structure, illuminated by a plane wave type probe. For this configuration, we studied the exact model and compared results with those of a linearized simplified model. This study emphasizes the ill-posed situation of the eddy current inverse problem related with the severe electromagnetic field attenuation. This means that regularization of the inverse problem, although absolutely necessary, will not be sufficient. Owing to the simplicity of the models available and implemented during the inversion process, processing real data would not yet be possible. We must first focus all our efforts on the direct 3 D problem, in conformity with the requirements of the inverse procedure ad describing a realistic eddy current NDT situation. At the same time, consideration should be given to the design of a specific probe customized for eddy current imaging. (authors). 9 refs., 5 figs., 3 appends

  18. Tangential 2-D Edge Imaging for GPI and Edge/Impurity Modeling

    Dr. Ricardo Maqueda; Dr. Fred M. Levinton

    2011-12-23

    Nova Photonics, Inc. has a collaborative effort at the National Spherical Torus Experiment (NSTX). This collaboration, based on fast imaging of visible phenomena, has provided key insights on edge turbulence, intermittency, and edge phenomena such as edge localized modes (ELMs) and multi-faceted axisymmetric radiation from the edge (MARFE). Studies have been performed in all these areas. The edge turbulence/intermittency studies make use of the Gas Puff Imaging diagnostic developed by the Principal Investigator (Ricardo Maqueda) together with colleagues from PPPL. This effort is part of the International Tokamak Physics Activity (ITPA) edge, scrape-off layer and divertor group joint activity (DSOL-15: Inter-machine comparison of blob characteristics). The edge turbulence/blob study has been extended from the current location near the midplane of the device to the lower divertor region of NSTX. The goal of this effort was to study turbulence born blobs in the vicinity of the X-point region and their circuit closure on divertor sheaths or high density regions in the divertor. In the area of ELMs and MARFEs we have studied and characterized the mode structure and evolution of the ELM types observed in NSTX, as well as the study of the observed interaction between MARFEs and ELMs. This interaction could have substantial implications for future devices where radiative divertor regions are required to maintain detachment from the divertor plasma facing components.

  19. Multifractal and Singularity Maps of soil surface moisture distribution derived from 2D image analysis.

    Cumbrera, Ramiro; Millán, Humberto; Martín-Sotoca, Juan Jose; Pérez Soto, Luis; Sanchez, Maria Elena; Tarquis, Ana Maria

    2016-04-01

    methods for mapping geochemical anomalies caused by buried sources and for predicting undiscovered mineral deposits in covered areas. Journal of Geochemical Exploration, 122, 55-70. Cumbrera, R., Ana M. Tarquis, Gabriel Gascó, Humberto Millán (2012) Fractal scaling of apparent soil moisture estimated from vertical planes of Vertisol pit images. Journal of Hydrology (452-453), 205-212. Martin Sotoca; J.J. Antonio Saa-Requejo, Juan Grau and Ana M. Tarquis (2016). Segmentation of singularity maps in the context of soil porosity. Geophysical Research Abstracts, 18, EGU2016-11402. Millán, H., Cumbrera, R. and Ana M. Tarquis (2016) Multifractal and Levy-stable statistics of soil surface moisture distribution derived from 2D image analysis. Applied Mathematical Modelling, 40(3), 2384-2395.

  20. A fast, accurate, and automatic 2D-3D image registration for image-guided cranial radiosurgery

    The authors developed a fast and accurate two-dimensional (2D)-three-dimensional (3D) image registration method to perform precise initial patient setup and frequent detection and correction for patient movement during image-guided cranial radiosurgery treatment. In this method, an approximate geometric relationship is first established to decompose a 3D rigid transformation in the 3D patient coordinate into in-plane transformations and out-of-plane rotations in two orthogonal 2D projections. Digitally reconstructed radiographs are generated offline from a preoperative computed tomography volume prior to treatment and used as the reference for patient position. A multiphase framework is designed to register the digitally reconstructed radiographs with the x-ray images periodically acquired during patient setup and treatment. The registration in each projection is performed independently; the results in the two projections are then combined and converted to a 3D rigid transformation by 2D-3D geometric backprojection. The in-plane transformation and the out-of-plane rotation are estimated using different search methods, including multiresolution matching, steepest descent minimization, and one-dimensional search. Two similarity measures, optimized pattern intensity and sum of squared difference, are applied at different registration phases to optimize accuracy and computation speed. Various experiments on an anthropomorphic head-and-neck phantom showed that, using fiducial registration as a gold standard, the registration errors were 0.33±0.16 mm (s.d.) in overall translation and 0.29 deg. ±0.11 deg. (s.d.) in overall rotation. The total targeting errors were 0.34±0.16 mm (s.d.), 0.40±0.2 mm (s.d.), and 0.51±0.26 mm (s.d.) for the targets at the distances of 2, 6, and 10 cm from the rotation center, respectively. The computation time was less than 3 s on a computer with an Intel Pentium 3.0 GHz dual processor

  1. Image enhancement of digital periapical radiographs according to diagnostic tasks

    his study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task. Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale. There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01). Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.

  2. Image enhancement of digital periapical radiographs according to diagnostic tasks

    Choi, Jin Woo; Han, Won Jeong; Kim, Eun Kyung [Dept. of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan (Korea, Republic of)

    2014-03-15

    his study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task. Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale. There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01). Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.

  3. A novel technique for single-shot energy-resolved 2D X-ray imaging of plasmas relevant for the Inertial Confinement Fusion

    Labate, L; Levato, T; Gizzi, L A

    2012-01-01

    A novel X-ray diagnostic of laser-fusion plasmas is described, allowing 2D monochromatic images of hot, dense plasmas to be obtained in any X-ray photon energy range, over a large domain, on a single-shot basis. The device (named Energy-encoded Pinhole Camera - EPiC) is based upon the use of an array of many pinholes coupled to a large area CCD camera operating in the single-photon mode. The available X-ray spectral domain is only limited by the Quantum Efficiency of scientific-grade X-ray CCD cameras, thus extending from a few keV up to a few tens of keV. Spectral 2D images of the emitting plasma can be obtained at any X-ray photon energy provided that a sufficient number of photons had been collected at the desired energy. Results from recent ICF related experiments will be reported in order to detail the new diagnostic.

  4. A novel technique for single-shot energy-resolved 2D x-ray imaging of plasmas relevant for the inertial confinement fusion.

    Labate, L; Köster, P; Levato, T; Gizzi, L A

    2012-10-01

    A novel x-ray diagnostic of laser-fusion plasmas is described, allowing 2D monochromatic images of hot, dense plasmas to be obtained in any x-ray photon energy range, over a large domain, on a single-shot basis. The device (named energy-encoded pinhole camera) is based upon the use of an array of many pinholes coupled to a large area CCD camera operating in the single-photon mode. The available x-ray spectral domain is only limited by the quantum efficiency of scientific-grade x-ray CCD cameras, thus extending from a few keV up to a few tens of keV. Spectral 2D images of the emitting plasma can be obtained at any x-ray photon energy provided that a sufficient number of photons had been collected at the desired energy. Results from recent inertial confinement fusion related experiments will be reported in order to detail the new diagnostic. PMID:23126763

  5. MR Neurography: Diagnostic Imaging in the PNS.

    Kollmer, J; Bendszus, M; Pham, M

    2015-10-01

    The diagnostic work-up of peripheral neuropathies is often challenging and is mainly based on a combination of clinical and electrophysiological examinations. One of the most important difficulties is the accurate determination of the lesion site (lesion localization), lesion extension, and spatial lesion dispersion, which all represent essential diagnostic information crucial for finding the correct diagnosis and hence an adequate therapeutic approach. A typical pitfall in the conventional diagnostic reasoning is the differentiation between a distal, complete cross-sectional nerve lesion and a more proximally located, fascicular nerve lesion. Magnetic resonance neurography (MRN) has been proven to be capable of improving the diagnostic accuracy by providing direct, noninvasive visualization of nerve injury with high structural resolution even reaching the anatomical level of single nerve fascicles (fascicular imaging) and at the same time with large anatomical coverage. It is also feasible to detect structural nerve damage earlier and with higher sensitivity than gold-standard nerve conduction studies. The purpose of this study is to review the literature for current developments and advances in MRN for the precise spatial detection of nerve lesions in focal and non-focal disorders of the peripheral nervous system. PMID:26070607

  6. Comparison of 3D cube FLAIR with 2D FLAIR for multiple sclerosis imaging at 3 tesla

    Purpose: Three-dimensional (3 D) MRI sequences allow improved spatial resolution with good signal and contrast properties as well as multiplanar reconstruction. We sought to compare Cube, a 3 D FLAIR sequence, to a standard 2 D FLAIR sequence in multiple sclerosis (MS) imaging. Materials and Methods: Examinations were performed in the clinical routine on a 3.0 Tesla scanner. 12 patients with definite MS were included. Lesions with MS-typical properties on the images of Cube FLAIR and 2 D FLAIR sequences were counted and allocated to different brain regions. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated. Results: With 384 the overall number of lesions found with Cube FLAIR was significantly higher than with 2 D FLAIR (N = 221). The difference was mostly accounted for by supratentorial lesions (N = 372 vs. N = 216) while the infratentorial lesion counts were low in both sequences. SNRs and CNRs were significantly higher in CUBE FLAIR with the exception of the CNR of lesion to gray matter, which was not significantly different. Conclusion: Cube FLAIR showed a higher sensitivity for MS lesions compared to a 2 D FLAIR sequence. 3 D FLAIR might replace 2 D FLAIR sequences in MS imaging in the future. (orig.)

  7. Comparison of 3D cube FLAIR with 2D FLAIR for multiple sclerosis imaging at 3 tesla

    Patzig, M.; Brueckmann, H.; Fesl, G. [Muenchen Univ. (Germany). Dept. of Neuroradiology; Burke, M. [GE Healthcare, Solingen (Germany)

    2014-05-15

    Purpose: Three-dimensional (3 D) MRI sequences allow improved spatial resolution with good signal and contrast properties as well as multiplanar reconstruction. We sought to compare Cube, a 3 D FLAIR sequence, to a standard 2 D FLAIR sequence in multiple sclerosis (MS) imaging. Materials and Methods: Examinations were performed in the clinical routine on a 3.0 Tesla scanner. 12 patients with definite MS were included. Lesions with MS-typical properties on the images of Cube FLAIR and 2 D FLAIR sequences were counted and allocated to different brain regions. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated. Results: With 384 the overall number of lesions found with Cube FLAIR was significantly higher than with 2 D FLAIR (N = 221). The difference was mostly accounted for by supratentorial lesions (N = 372 vs. N = 216) while the infratentorial lesion counts were low in both sequences. SNRs and CNRs were significantly higher in CUBE FLAIR with the exception of the CNR of lesion to gray matter, which was not significantly different. Conclusion: Cube FLAIR showed a higher sensitivity for MS lesions compared to a 2 D FLAIR sequence. 3 D FLAIR might replace 2 D FLAIR sequences in MS imaging in the future. (orig.)

  8. MRI as an adjunct to echocardiography for the diagnostic imaging of cardiac masses

    Nine patients underwent magnetic resonance imaging (MRI) as part of the diagnostic evaluation for cardiac masses; eight of them had been preliminary studied by 2D-echocardiography (US). MRI did not add to the US diagnostic information in patients affected by intracavitary masses. It represented the definitive diagnostic modality in two patients with intramural pathology: one with ventricular rhabdomyoma, the second with an echinococcyal cyst located within the left atrial wall. The complementary role of MRI to US in cardiac masses is discussed. (orig.)

  9. Automatic 2D segmentation of airways in thorax computed tomography images; Segmentacao automatica 2D de vias aereas em imagens de tomografia computadorizada do torax

    Cavalcante, Tarique da Silveira; Cortez, Paulo Cesar; Almeida, Thomaz Maia de, E-mail: tarique@lesc.ufc.br [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia de Teleinformatica; Felix, John Hebert da Silva [Universidade da Integracao Internacional da Lusofonia Afro-Brasileira (UNILAB), Redencao, CE (Brazil). Departamento de Energias; Holanda, Marcelo Alcantara [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Fac. de Medicina

    2013-07-01

    Introduction: much of the world population is affected by pulmonary diseases, such as the bronchial asthma, bronchitis and bronchiectasis. The bronchial diagnosis is based on the airways state. In this sense, the automatic segmentation of the airways in Computed Tomography (CT) scans is a critical step in the aid to diagnosis of these diseases. Methods: this paper evaluates algorithms for airway automatic segmentation, using Neural Network Multilayer Perceptron (MLP) and Lung Densities Analysis (LDA) for detecting airways, along with Region Growing (RG), Active Contour Method (ACM) Balloon and Topology Adaptive to segment them. Results: we obtained results in three stages: comparative analysis of the detection algorithms MLP and LDA, with a gold standard acquired by three physicians with expertise in CT imaging of the chest; comparative analysis of segmentation algorithms ACM Balloon, ACM Topology Adaptive, MLP and RG; and evaluation of possible combinations between segmentation and detection algorithms, resulting in the complete method for automatic segmentation of the airways in 2D. Conclusion: the low incidence of false negative and the significant reduction of false positive, results in similarity coefficient and sensitivity exceeding 91% and 87% respectively, for a combination of algorithms with satisfactory segmentation quality. (author)

  10. Diagnostic imaging in pediatric renal inflammatory disease

    Some form of imaging procedure should be used to document the presence of infection of the upper urinary tract in troublesome cases in children. During the past several years, sonography, nuclear radiology, and computed tomography (CT) have had a significant influence on renal imaging. The purpose of this article is to reevaluate the noninvasive imaging procedures that can be used to diagnose pediatric renal inflammatory disease and to assess the relative value of each modality in the various types of renal infection. The authors will not discuss the radiologic evaluation of the child who has had a previous renal infection, in whom cortical scarring or reflux nephropathy is a possibility; these are different clinical problems and require different diagnostic evaluation

  11. Registration of 2D x-ray images to 3D MRI by generating pseudo-CT data

    van der Bom, M. J.; Pluim, J. P. W.; Gounis, M. J.; van de Kraats, E. B.; Sprinkhuizen, S. M.; Timmer, J.; Homan, R.; Bartels, L. W.

    2011-02-01

    Spatial and soft tissue information provided by magnetic resonance imaging can be very valuable during image-guided procedures, where usually only real-time two-dimensional (2D) x-ray images are available. Registration of 2D x-ray images to three-dimensional (3D) magnetic resonance imaging (MRI) data, acquired prior to the procedure, can provide optimal information to guide the procedure. However, registering x-ray images to MRI data is not a trivial task because of their fundamental difference in tissue contrast. This paper presents a technique that generates pseudo-computed tomography (CT) data from multi-spectral MRI acquisitions which is sufficiently similar to real CT data to enable registration of x-ray to MRI with comparable accuracy as registration of x-ray to CT. The method is based on a k-nearest-neighbors (kNN)-regression strategy which labels voxels of MRI data with CT Hounsfield Units. The regression method uses multi-spectral MRI intensities and intensity gradients as features to discriminate between various tissue types. The efficacy of using pseudo-CT data for registration of x-ray to MRI was tested on ex vivo animal data. 2D-3D registration experiments using CT and pseudo-CT data of multiple subjects were performed with a commonly used 2D-3D registration algorithm. On average, the median target registration error for registration of two x-ray images to MRI data was approximately 1 mm larger than for x-ray to CT registration. The authors have shown that pseudo-CT data generated from multi-spectral MRI facilitate registration of MRI to x-ray images. From the experiments it could be concluded that the accuracy achieved was comparable to that of registering x-ray images to CT data.

  12. Refraction-based 2D, 2.5D and 3D medical imaging: Stepping forward to a clinical trial

    Ando, Masami [Tokyo University of Science, Research Institute for Science and Technology, Noda, Chiba 278-8510 (Japan)], E-mail: msm-ando@rs.noda.tus.ac.jp; Bando, Hiroko [Tsukuba University (Japan); Tokiko, Endo; Ichihara, Shu [Nagoya Medical Center (Japan); Hashimoto, Eiko [GUAS (Japan); Hyodo, Kazuyuki [KEK (Japan); Kunisada, Toshiyuki [Okayama University (Japan); Li Gang [BSRF (China); Maksimenko, Anton [Tokyo University of Science, Research Institute for Science and Technology, Noda, Chiba 278-8510 (Japan); KEK (Japan); Mori, Kensaku [Nagoya University (Japan); Shimao, Daisuke [IPU (Japan); Sugiyama, Hiroshi [KEK (Japan); Yuasa, Tetsuya [Yamagata University (Japan); Ueno, Ei [Tsukuba University (Japan)

    2008-12-15

    An attempt at refraction-based 2D, 2.5D and 3D X-ray imaging of articular cartilage and breast carcinoma is reported. We are developing very high contrast X-ray 2D imaging with XDFI (X-ray dark-field imaging), X-ray CT whose data are acquired by DEI (diffraction-enhanced imaging) and tomosynthesis due to refraction contrast. 2D and 2.5D images were taken with nuclear plates or with X-ray films. Microcalcification of breast cancer and articular cartilage are clearly visible. 3D data were taken with an X-ray sensitive CCD camera. The 3D image was successfully reconstructed by the use of an algorithm newly made by our group. This shows a distinctive internal structure of a ductus lactiferi (milk duct) that contains inner wall, intraductal carcinoma and multifocal calcification in the necrotic core of the continuous DCIS (ductal carcinoma in situ). Furthermore consideration of clinical applications of these contrasts made us to try tomosynthesis. This attempt was satisfactory from the view point of articular cartilage image quality and the skin radiation dose.

  13. Refraction-based 2D, 2.5D and 3D medical imaging: Stepping forward to a clinical trial

    An attempt at refraction-based 2D, 2.5D and 3D X-ray imaging of articular cartilage and breast carcinoma is reported. We are developing very high contrast X-ray 2D imaging with XDFI (X-ray dark-field imaging), X-ray CT whose data are acquired by DEI (diffraction-enhanced imaging) and tomosynthesis due to refraction contrast. 2D and 2.5D images were taken with nuclear plates or with X-ray films. Microcalcification of breast cancer and articular cartilage are clearly visible. 3D data were taken with an X-ray sensitive CCD camera. The 3D image was successfully reconstructed by the use of an algorithm newly made by our group. This shows a distinctive internal structure of a ductus lactiferi (milk duct) that contains inner wall, intraductal carcinoma and multifocal calcification in the necrotic core of the continuous DCIS (ductal carcinoma in situ). Furthermore consideration of clinical applications of these contrasts made us to try tomosynthesis. This attempt was satisfactory from the view point of articular cartilage image quality and the skin radiation dose

  14. 2D/4D marker-free tumor tracking using 4D CBCT as the reference image

    Tumor motion caused by respiration is an important issue in image-guided radiotherapy. A 2D/4D matching method between 4D volumes derived from cone beam computed tomography (CBCT) and 2D fluoroscopic images was implemented to track the tumor motion without the use of implanted markers. In this method, firstly, 3DCBCT and phase-rebinned 4DCBCT are reconstructed from cone beam acquisition. Secondly, 4DCBCT volumes and a streak-free 3DCBCT volume are combined to improve the image quality of the digitally reconstructed radiographs (DRRs). Finally, the 2D/4D matching problem is converted into a 2D/2D matching between incoming projections and DRR images from each phase of the 4DCBCT. The diaphragm is used as a target surrogate for matching instead of using the tumor position directly. This relies on the assumption that if a patient has the same breathing phase and diaphragm position as the reference 4DCBCT, then the tumor position is the same. From the matching results, the phase information, diaphragm position and tumor position at the time of each incoming projection acquisition can be derived. The accuracy of this method was verified using 16 candidate datasets, representing lung and liver applications and one-minute and two-minute acquisitions. The criteria for the eligibility of datasets were described: 11 eligible datasets were selected to verify the accuracy of diaphragm tracking, and one eligible dataset was chosen to verify the accuracy of tumor tracking. The diaphragm matching accuracy was 1.88 ± 1.35 mm in the isocenter plane and the 2D tumor tracking accuracy was 2.13 ± 1.26 mm in the isocenter plane. These features make this method feasible for real-time marker-free tumor motion tracking purposes. (paper)

  15. 2D/4D marker-free tumor tracking using 4D CBCT as the reference image

    Wang, Mengjiao; Sharp, Gregory C.; Rit, Simon; Delmon, Vivien; Wang, Guangzhi

    2014-05-01

    Tumor motion caused by respiration is an important issue in image-guided radiotherapy. A 2D/4D matching method between 4D volumes derived from cone beam computed tomography (CBCT) and 2D fluoroscopic images was implemented to track the tumor motion without the use of implanted markers. In this method, firstly, 3DCBCT and phase-rebinned 4DCBCT are reconstructed from cone beam acquisition. Secondly, 4DCBCT volumes and a streak-free 3DCBCT volume are combined to improve the image quality of the digitally reconstructed radiographs (DRRs). Finally, the 2D/4D matching problem is converted into a 2D/2D matching between incoming projections and DRR images from each phase of the 4DCBCT. The diaphragm is used as a target surrogate for matching instead of using the tumor position directly. This relies on the assumption that if a patient has the same breathing phase and diaphragm position as the reference 4DCBCT, then the tumor position is the same. From the matching results, the phase information, diaphragm position and tumor position at the time of each incoming projection acquisition can be derived. The accuracy of this method was verified using 16 candidate datasets, representing lung and liver applications and one-minute and two-minute acquisitions. The criteria for the eligibility of datasets were described: 11 eligible datasets were selected to verify the accuracy of diaphragm tracking, and one eligible dataset was chosen to verify the accuracy of tumor tracking. The diaphragm matching accuracy was 1.88 ± 1.35 mm in the isocenter plane and the 2D tumor tracking accuracy was 2.13 ± 1.26 mm in the isocenter plane. These features make this method feasible for real-time marker-free tumor motion tracking purposes.

  16. 3D ultrasound imaging performance of a row-column addressed 2D array transducer: a simulation study

    Rasmussen, Morten Fischer; Jensen, Jørgen Arendt

    2013-01-01

    This paper compares the imaging performance of a 128+128 element row-column addressed array with a fully addressed 1616 2D array. The comparison is made via simulations of the point spread function with Field II. Both arrays have lambda-pitch, a center frequency of 3:5MHz and use 256 active...

  17. RegStatGel: proteomic software for identifying differentially expressed proteins based on 2D gel images

    Li, Feng; Seillier-Moiseiwitsch, Françoise

    2011-01-01

    Image analysis of two-dimensional gel electrophoresis is a key step in proteomic workflow for identifying proteins that change under different experimental conditions. Since there are usually large amount of proteins and variations shown in the gel images, the use of software for analysis of 2D gel images is inevitable. We developed open-source software with graphical user interface for differential analysis of 2D gel images. The user-friendly software, RegStatGel, contains fully automated as well as interactive procedures. It was developed and has been tested under Matlab 7.01. Availability The database is available for free at http://www.mediafire.com/FengLi/2DGelsoftware PMID:21904427

  18. An automatic 2D CAD algorithm for the segmentation of the IMT in ultrasound carotid artery images

    Ilea, Dana E.; Whelan, Paul F.; Brown, C.; Stanton, A

    2009-01-01

    Common carotid intima-media thickness (IMT) is a reliable measure of early atherosclerosis - its accurate measurement can be used in the process of evaluating the presence and tracking the progression of disease. The aim of this study is to introduce a novel unsupervised Computer Aided Detection (CAD) algorithm that is able to identify and measure the IMT in 2D ultrasound carotid images. The developed technique relies on a suite of image processing algorithms that embeds a statistical model t...

  19. Preliminary Investigation: 2D-3D Registration of MR and X-ray Cardiac Images Using Catheter Constraints

    Truong, Michael V.N.; Aslam, Abdullah; Rinaldi, Christopher Aldo; Razavi, Reza; Penney, Graeme P.; Rhode, Kawal

    2009-01-01

    Cardiac catheterization procedures are routinely guided by X-ray fluoroscopy but suffer from poor soft-tissue contrast and a lack of depth information. These procedures often employ pre-operative magnetic resonance or computed tomography imaging for treatment planning due to their excellent soft-tissue contrast and 3D imaging capabilities. We developed a 2D-3D image registration method to consolidate the advantages of both modalities by overlaying the 3D images onto the X-ray. Our method uses...

  20. Usefulness of diagnostic imaging in primary hyperparathyroidism

    Sekiyama, Kazuya; Akakura, Koichiro; Mikami, Kazuo; Mizoguchi, Ken-ichi; Tobe, Toyofusa; Nakano, Koichi; Numata, Tsutomu; Konno, Akiyoshi; Ito, Haruo [Chiba Univ. (Japan). Graduate School of Medicine

    2003-01-01

    In patients with primary hyperparathyroidism, prevention of urinary stone recurrence can be achieved by surgical removal of the enlarged parathyroid gland. To ensure the efficacy of surgery for primary hyperparathyroidism, preoperative localization of the enlarged gland is important. In the present study, usefulness of diagnostic imaging for localization of the enlarged gland was investigated in primary hyperparathyroidism. We retrospectively examined the findings of imaging studies and clinical records in 79 patients (97 glands) who underwent surgical treatment for primary hyperparathyroidism at Chiba University Hospital between 1976 and 2000. The detection rates of accurate localization were investigated for imaging techniques, such as ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI) thallium-201 and technetium-99m pertechnetate (Tl-Tc) subtraction scintigraphy and {sup 99m}Tc-methoxyisobutylisonitrile (MIBI) scintigraphy, and analysed in relation to the size and weight of the gland and pathological diagnosis. The detection rates by US, CT, MRI, Tl-Tc subtraction scintigraphy and MIBI scintigraphy were 70%, 67%, 73%, 38% and 78%, respectively. The overall detection rate changed from 50% to 88% before and after 1987. The detection rate of MIBI scintigraphy was superior to Tl-Tc subtraction scintigraphy. In primary hyperparathyroidism, improvement of accurate localization of an enlarged parathyroid gland was demonstrated along with recent advances in imaging techniques including MIBI scintigraphy. (author)

  1. Diagnostic imaging of the diabetic foot

    Diabetic foot syndrome is a significant complication of diabetes. Diagnostic imaging is a crucial factor determining surgical decision and extent of surgical intervention. At present the gold standard is MRI scanning, whilst the role of bone scanning is decreasing, although in some cases it brings valuable information. In particular, in early stages of osteitis and Charcot neuro-osteoarthropathy, radionuclide imaging may be superior to MRI. Additionally, a significant contribution of inflammation-targeted scintigraphy should be noted. Probably the role of PET scanning will grow, although its high cost and low availability may be a limiting factor. In every case, vascular status should be determined, at least with Doppler ultrasound, with following conventional angiography or MR angiography. (authors)

  2. Development and validation of a modelling framework for simulating 2D-mammography and breast tomosynthesis images.

    Elangovan, Premkumar; Warren, Lucy M; Mackenzie, Alistair; Rashidnasab, Alaleh; Diaz, Oliver; Dance, David R; Young, Kenneth C; Bosmans, Hilde; Strudley, Celia J; Wells, Kevin

    2014-08-01

    Planar 2D x-ray mammography is generally accepted as the preferred screening technique used for breast cancer detection. Recently, digital breast tomosynthesis (DBT) has been introduced to overcome some of the inherent limitations of conventional planar imaging, and future technological enhancements are expected to result in the introduction of further innovative modalities. However, it is crucial to understand the impact of any new imaging technology or methodology on cancer detection rates and patient recall. Any such assessment conventionally requires large scale clinical trials demanding significant investment in time and resources. The concept of virtual clinical trials and virtual performance assessment may offer a viable alternative to this approach. However, virtual approaches require a collection of specialized modelling tools which can be used to emulate the image acquisition process and simulate images of a quality indistinguishable from their real clinical counterparts. In this paper, we present two image simulation chains constructed using modelling tools that can be used for the evaluation of 2D-mammography and DBT systems. We validate both approaches by comparing simulated images with real images acquired using the system being simulated. A comparison of the contrast-to-noise ratios and image blurring for real and simulated images of test objects shows good agreement ( < 9% error). This suggests that our simulation approach is a promising alternative to conventional physical performance assessment followed by large scale clinical trials. PMID:25029333

  3. Development and validation of a modelling framework for simulating 2D-mammography and breast tomosynthesis images

    Planar 2D x-ray mammography is generally accepted as the preferred screening technique used for breast cancer detection. Recently, digital breast tomosynthesis (DBT) has been introduced to overcome some of the inherent limitations of conventional planar imaging, and future technological enhancements are expected to result in the introduction of further innovative modalities. However, it is crucial to understand the impact of any new imaging technology or methodology on cancer detection rates and patient recall. Any such assessment conventionally requires large scale clinical trials demanding significant investment in time and resources. The concept of virtual clinical trials and virtual performance assessment may offer a viable alternative to this approach. However, virtual approaches require a collection of specialized modelling tools which can be used to emulate the image acquisition process and simulate images of a quality indistinguishable from their real clinical counterparts. In this paper, we present two image simulation chains constructed using modelling tools that can be used for the evaluation of 2D-mammography and DBT systems. We validate both approaches by comparing simulated images with real images acquired using the system being simulated. A comparison of the contrast-to-noise ratios and image blurring for real and simulated images of test objects shows good agreement ( < 9% error). This suggests that our simulation approach is a promising alternative to conventional physical performance assessment followed by large scale clinical trials. (paper)

  4. 2D Satellite Image Registration Using Transform Based and Correlation Based Methods

    Dr. H.B. Kekre, Dr. Tanuja K. Sarode, Ms. Ruhina B. Karani

    2012-01-01

    Image registration is the process of geometrically aligning one image to another image of the same scene taken from different viewpoints or by different sensors. It is a fundamental image processing technique and is very useful in integrating information from different sensors, finding changes in images taken at different times and inferring three-dimensional information from stereo images. Image registration can be done by using two matching method: transform based methods and correlation ba...

  5. 3D structural measurements of the proximal femur from 2D DXA images using a statistical atlas

    Ahmad, Omar M.; Ramamurthi, Krishna; Wilson, Kevin E.; Engelke, Klaus; Bouxsein, Mary; Taylor, Russell H.

    2009-02-01

    A method to obtain 3D structural measurements of the proximal femur from 2D DXA images and a statistical atlas is presented. A statistical atlas of a proximal femur was created consisting of both 3D shape and volumetric density information and then deformably registered to 2D fan-beam DXA images. After the registration process, a series of 3D structural measurements were taken on QCT-estimates generated by transforming the registered statistical atlas into a voxel volume. These measurements were compared to the equivalent measurements taken on the actual QCT (ground truth) associated with the DXA images for each of 20 human cadaveric femora. The methodology and results are presented to address the potential clinical feasibility of obtaining 3D structural measurements from limited angle DXA scans and a statistical atlas of the proximal femur in-vivo.

  6. Estimation of 3-D pore network coordination number of rocks from watershed segmentation of a single 2-D image

    Rabbani, Arash; Ayatollahi, Shahab; Kharrat, Riyaz; Dashti, Nader

    2016-08-01

    In this study, we have utilized 3-D micro-tomography images of real and synthetic rocks to introduce two mathematical correlations which estimate the distribution parameters of 3-D coordination number using a single 2-D cross-sectional image. By applying a watershed segmentation algorithm, it is found that the distribution of 3-D coordination number is acceptably predictable by statistical analysis of the network extracted from 2-D images. In this study, we have utilized 25 volumetric images of rocks in order to propose two mathematical formulas. These formulas aim to approximate the average and standard deviation of coordination number in 3-D pore networks. Then, the formulas are applied for five independent test samples to evaluate the reliability. Finally, pore network flow modeling is used to find the error of absolute permeability prediction using estimated and measured coordination numbers. Results show that the 2-D images are considerably informative about the 3-D network of the rocks and can be utilized to approximate the 3-D connectivity of the porous spaces with determination coefficient of about 0.85 that seems to be acceptable considering the variety of the studied samples.

  7. Initial Images of the Synthetic Aperture Radiometer 2D-STAR

    Initial results obtained using a new synthetic aperture radiometer, 2D-STAR, a dual polarized, L-band radiometer that employs aperture synthesis in two dimensions are presented and analyzed. This airborne instrument is the natural evolution of a previous design that employed employs aperture synthes...

  8. Diagnostic imaging of acute aortic dissection

    One hundred and nineteen patients with aortic dissection who underwent diagnostic imaging were reviewed and angiographic findings as well as those of CT were analysed. Thirty eight cases (43.1%) had non-contrast opacified false lumen, the type of which we call 'thrombosed type aortic dissection'. A comparative study of the thrombosed type with the patent type of false lumens was made particularly from the stand point of the characteristic diagnostic imagings (CT and angiography). At the same time, the pitfalls of these imagings in thrombosed type aortic dissection were studied. At the onset the average age of thrombosed type was 62.3 years old, while that of the patent type was 57.3. A statistical significance between the two groups was p<0.05. Thrombosed type in all cases was caused by atherosclerosis, whereas patent type was caused by the Marfan's syndrome in 11 cases. Other clinical findings, such as initial symptoms and blood pressure revealed no significant differences between the two groups. Pre-contrast CT in acute thrombosed type aortic dissection showed 'hyperdense crescent sign' in 89.4%. However, in 3 cases with thrombosed type in which the pre-contrast CT showed 'hyperdense crescent sign' contrast-enhanced CT detected no clear evidence of aortic dissection in the same site. This was due to obscurity induced by contrast medium. Angiographic findings of thrombosed type were classified into 3 groups: normal type, stenosed true lumen type and ulcer-like projection type. The incidence of normal type was estimated to be 48.4%, whereas stenosed true lumen type was 24.2% and ulcer-like projection was 27.7%. The present study concluded that thrombosed type is not rare in acute aortic dissection and contrast-enhanced CT as well as pre-contrast CT, is of great value in diagnosing thrombosed type. 'Hyperdense crescent sign' in pre-contrast CT is characteristic of intramural hematoma. (author)

  9. Numerical correction of anti-symmetric aberrations in single HRTEM images of weakly scattering 2D-objects

    Lehtinen, Ossi, E-mail: ossi.lehtinen@gmail.com [Central Facility for Electron Microscopy, Group of Electron Microscopy of Materials Science, University of Ulm, 89081 Ulm (Germany); Geiger, Dorin; Lee, Zhongbo [Central Facility for Electron Microscopy, Group of Electron Microscopy of Materials Science, University of Ulm, 89081 Ulm (Germany); Whitwick, Michael Brian; Chen, Ming-Wei; Kis, Andras [Electrical Engineering Institute, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Kaiser, Ute [Central Facility for Electron Microscopy, Group of Electron Microscopy of Materials Science, University of Ulm, 89081 Ulm (Germany)

    2015-04-15

    Here, we present a numerical post-processing method for removing the effect of anti-symmetric residual aberrations in high-resolution transmission electron microscopy (HRTEM) images of weakly scattering 2D-objects. The method is based on applying the same aberrations with the opposite phase to the Fourier transform of the recorded image intensity and subsequently inverting the Fourier transform. We present the theoretical justification of the method, and its verification based on simulated images in the case of low-order anti-symmetric aberrations. Ultimately the method is applied to experimental hardware aberration-corrected HRTEM images of single-layer graphene and MoSe{sub 2} resulting in images with strongly reduced residual low-order aberrations, and consequently improved interpretability. Alternatively, this method can be used to estimate by trial and error the residual anti-symmetric aberrations in HRTEM images of weakly scattering objects.

  10. Invariant image description for the improvement of medical diagnostics

    Nagel, Joachim H.

    1994-01-01

    In summary, invariant image description has proven to be an extremely successful tool for medical image processing and has already contributed significantly to the improvement of clinical diagnostics. The technique has been widely acknowledged as being superior to other methods of image registration. Further applications, not limited to medical diagnostics, are to be expected.

  11. Rigid 2D/3D slice-to-volume registration and its application on fluoroscopic CT images

    Registration of single slices from FluoroCT, CineMR, or interventional magnetic resonance imaging to three dimensional (3D) volumes is a special aspect of the two-dimensional (2D)/3D registration problem. Rather than digitally rendered radiographs (DRR), single 2D slice images obtained during interventional procedures are compared to oblique reformatted slices from a high resolution 3D scan. Due to the lack of perspective information and the different imaging geometry, convergence behavior differs significantly from 2D/3D registration applications comparing DRR images with conventional x-ray images. We have implemented a number of merit functions and local and global optimization algorithms for slice-to-volume registration of computed tomography (CT) and FluoroCT images. These methods were tested on phantom images derived from clinical scans for liver biopsies. Our results indicate that good registration accuracy in the range of 0.5 degree sign and 1.0 mm is achievable using simple cross correlation and repeated application of local optimization algorithms. Typically, a registration took approximately 1 min on a standard personal computer. Other merit functions such as pattern intensity or normalized mutual information did not perform as well as cross correlation in this initial evaluation. Furthermore, it appears as if the use of global optimization algorithms such as simulated annealing does not improve reliability or accuracy of the registration process. These findings were also confirmed in a preliminary registration study on five clinical scans. These experiments have, however, shown that a strict breath-hold protocol is inevitable when using rigid registration techniques for lesion localization in image-guided biopsy retrieval. Finally, further possible applications of slice-to-volume registration are discussed

  12. 2D and 3D CT imaging correlated to rigid endoscopy in complex laryngo-tracheal stenoses

    The aim of this study was to compare 2D and 3D CT imaging in the pre- and postoperative evaluation of complex benign laryngestracheal airway stenoses with rigid endoscopy, considered as the gold standard. Six patients (aged 5-72 years) with a total of nine complex laryngo-tracheal stenoses underwent non-contrast helical CT scans (slice thickness 3 mm, pitch 1.3, reconstruction interval 1.5 mm) before and after surgical resection. With prototype software, virtual endoscopy (VE) post-processing algorithms were applied to the imaging data sets. The VE and multiplanar 2D findings were compared with rigid endoscopy, considered as standard of reference. All nine stenoses were correctly identified on 3D images and their anatomical locations correctly assessed on 2D reconstructions. Artifacts were met when patients were unable to suspend their breath, leading to one false-positive result. Two-dimensional images and 3D VE of tracheal stenoses proved to be efficient and complementary to the rigid endoscopy, permitting a reliable endoluminal 3D view and evaluation of the surrounding anatomical structures. (orig.)

  13. 2D and 3D CT imaging correlated to rigid endoscopy in complex laryngo-tracheal stenoses

    Gluecker, T.; Meuli, R.; Schnyder, P.; Duvoisin, B. [CHUV, Lausanne (Switzerland). Dept. of Diagnostic and Interventional Radiology; Lang, F.; Bessler, S.; Monnier, P. [Dept. of Oto-Rhino-Laryngology, CHUV Lausanne, Lausanne (Switzerland)

    2001-01-01

    The aim of this study was to compare 2D and 3D CT imaging in the pre- and postoperative evaluation of complex benign laryngestracheal airway stenoses with rigid endoscopy, considered as the gold standard. Six patients (aged 5-72 years) with a total of nine complex laryngo-tracheal stenoses underwent non-contrast helical CT scans (slice thickness 3 mm, pitch 1.3, reconstruction interval 1.5 mm) before and after surgical resection. With prototype software, virtual endoscopy (VE) post-processing algorithms were applied to the imaging data sets. The VE and multiplanar 2D findings were compared with rigid endoscopy, considered as standard of reference. All nine stenoses were correctly identified on 3D images and their anatomical locations correctly assessed on 2D reconstructions. Artifacts were met when patients were unable to suspend their breath, leading to one false-positive result. Two-dimensional images and 3D VE of tracheal stenoses proved to be efficient and complementary to the rigid endoscopy, permitting a reliable endoluminal 3D view and evaluation of the surrounding anatomical structures. (orig.)

  14. 2D Satellite Image Registration Using Transform Based and Correlation Based Methods

    Dr. H.B. Kekre, Dr. Tanuja K. Sarode, Ms. Ruhina B. Karani

    2012-05-01

    Full Text Available Image registration is the process of geometrically aligning one image to another image of the same scene taken from different viewpoints or by different sensors. It is a fundamental image processing technique and is very useful in integrating information from different sensors, finding changes in images taken at different times and inferring three-dimensional information from stereo images. Image registration can be done by using two matching method: transform based methods and correlation based methods. When image registration is done using correlation based methods like normalized cross correlation, the results are slow. They are also computationally complex and sensitive to the image intensity changes which are caused by noise and varying illumination. In this paper, an unusual form of image registration is proposed which focuses upon using various transforms for fast and accurate image registration. The data set can be a set of photographs, data from various sensors, from different times, or from different viewpoints. The applications of image registration are in the field of computer vision, medical imaging, military automatic target recognition, and in analyzing images and data from satellites. The proposed technique works on satellite images. It tries to find out area of interest by comparing the unregistered image with source image and finding the part that has highest similarity matching. The paper mainly works on the concept of seeking water or land in the stored image. The proposed technique uses different transforms like Discrete Cosine Transform, Discrete Wavelet Transform, HAAR Transform and Walsh transform to achieve accurate image registration. The paper also focuses upon using normalized cross correlation as an area based technique of image registration for the purpose of comparison. The root mean square error is used as similarity measure. Experimental results show that the proposed algorithm can successfully register the

  15. Visible Imaging Diagnostic on Tore-Supra

    Dachicourt, R.; Monier Garbet, P.; Beaute, A.; Habib-Naiim, M. [Association Euratom-CEA, CEA/DSM/IRFM, CEA Cadarache (France); Marandet, Y. [PIIM, CNRS-Universite de Provence, Marseille (France)

    2011-07-01

    Full text of publication follows: Research for thermonuclear fusion aims at energy production using fusion reactions between deuterium and tritium nuclei. To this end, a deuterium/tritium mixture has to be heated to a very high temperature (about 100 millions degrees). Chemical and physical sputtering erodes the plasma facing components (PFC), leading to an impurity influx to the plasma. Estimating this erosion source is important both for the PFC lifetime and the quality of the confinement. In fact, impurities reaching the plasma core radiate energy and dilute the fuel. In this contribution, we describe an erosion diagnostic operated on the Tore Supra tokamak, consisting in the combination of visible spectroscopy and filtered imaging over a full TPL (Toroidal Pumped Limiter) sector. Quantitative measurements of spectral lines brightness on four spectrometer chords monitoring the TPL top are used to process the corresponding filtered images, namely to remove background emission or unwanted lines. The particle influx from the TPL's vicinity is obtained from photon fluxes measurements [1], which require absolute calibration in intensity of the system. Filtered images provide the spatial pattern of erosion, from which the total eroded carbon flux is reconstructed. The variation of the particle influx with the input power is studied by analyzing a dedicated experimental campaign. References: [1] Behringer K. et al. Plasma Physics and Controlled Fusion, Vol. 31, No. 14, pp. 2059 to 2099, 1989. (authors)

  16. Application of 2D/3D Image Registration in the Radiotherapy of Nasopharyngeal Carcinoma%2D/3D影像配准在鼻咽癌放疗中的应用

    马广栋; 洪莉; 王亮和

    2013-01-01

    目的:研究2D/3D像配准方法对鼻咽癌放疗中计划靶区PTV外扩距离的影响。方法应用OBI (On Board Image,OBI)系统获取2D影像(kV图像和PV图像)和3D影像(CBCT图像),将获取的2D和3D影像分别经DRR配准系统和模拟定位CT进行图像配准,确定前后、头脚、左右3个方向上的摆位误差,再由2种PTV外扩公式计算3个方向上的PTV外扩距离。结果2D和3D影像配准的PTV外扩值有所不同。kV,PV,CBCT三者配准误差相互比较P>0.05,无统计学意义。结论kV图像和PV图像和CBCT图像都能很好地验证照射野位置。CBCT图像可以分析三维方向的影像误差,降低了2D图像影像重叠产生的摆位误差的影响。%Objective To study the effect of 2D/3D image registration on the extended distance of planning target volume (PTV) in the radiotherapy of nasopharyngeal carcinoma (NPC). Methods Using OBI system to obtain two-dimensional images (kV images and PV images) and three-dimensional images (CBCT images). Then registering 2D and 3D images by using DRR registration system and simulation positioning CT respectively to get the set-up errors of VRT, LNG, LAT. Then calculating the values of PTV extended distance of VRT, LNG, LAT with two kinds of PTV expansion formulas. Results The values of PTV extended distance between 2D and 3D images are different while there is no signiifcance in registration errors among kV, PV, CBCT images (P>0.05). Conclusion Both of 2D images (kV images and PV images) and 3D images (CBCT images) can verify the radiation field well. 3D image errors can be analyzed with CBCT images, which can reduce the inlfuence of set-up errors caused by image overlapping of 2D images.

  17. Magnetic resonance imaging of the cervical spine: comparison of 2D T2-weighted turbo spin echo, 2D T2*weighted gradient-recalled echo and 3D T2-weighted variable flip-angle turbo spin echo sequences

    To compare an isotropic three-dimensional (3D) high-resolution T2-weighted (w) MR sequence and its reformations with conventional sequences for imaging of the cervical spine. Fifteen volunteers were examined at 1.5 T using sagittal and axial 3D T2-w, sagittal and axial 2D T2w, and axial 2D T2*w MR sequences. Axial reformations of the sagittal 3D dataset were generated (3D MPR T2w). Signal-to-noise and image homogeneity were evaluated in a phantom and in vivo. Visibility of ten anatomical structures of the cervical spine was evaluated. Artifacts were assessed. For statistical analysis, Cohen's kappa, Wilcoxon matched pairs, and t-testing were utilized. There were no significant differences in homogeneity between the sequences. Sagittal 3D T2w enabled better delineation of nerve roots, neural foramina, and intraforaminal structures compared to sagittal 2D T2w. Axial 3D T2w and axial 3D MPR T2w resulted in superior visibility of most anatomical structures compared to axial 2D T2w and comparable results to 2D T2*w concerning the spinal cord, nerve roots, intraforaminal structures, and fat. Artifacts were most pronounced in axial 2D T2w and axial 3D T2w. Acquisition of a 3D T2w data set is feasible in the cervical spine with superior delineation of anatomical structures compared to 2D sequences. (orig.)

  18. Diagnostic imaging and radiation therapy equipment

    This is the third edition of CSA Standard C22.2 No. 114 (now CAN/CSA-C22.2 No. 114), which is one of a series of standards issued by the Canadian Standards Association under Part II of the Canadian Electrical Code. This edition marks an important shift towards harmonization of Canadian requirements with those of the European community and the United States. Also important to this edition is the expansion of its scope to include the complete range of diagnostic imaging and radiation therapy equipment, rather than solely radiation-emitting equipment. In so doing, equipment previously addressed by CSA Standard C22.2 No. 125, Electromedical Equipment, specifically lasers for medical applications and diagnostic ultrasound units, is now dealt with in the new edition. By virtue of this expanded scope, many of the technical requirements in the electromedical equipment standard have been introduced to the new edition, thereby bringing CSA Standard C22.2 No. 114 up to date. 14 tabs., 16 figs

  19. Study on the imaging ability of the 2D neutron detector based on MWPC

    LiChao, Tian; YuanBo, Chen; Bin, Tang; JianRong, Zhou; HuiRong, Qi; RongGuang, Liu; Zhang JIAN; GuiAn, Yang; HONG, XU; DongFeng, Chen; ZhiJia, Sun

    2013-01-01

    A 2D neutron detector based on 3He convertor and MWPC with an active area of 200 mm \\times 200 mm has been successfully designed and fabricated. The detector has been tested with Am/Be neutron source and with collimated neutron beam with wavelength of {\\lambda} = 1.37 {\\AA}. A best spatial resolution of 1.18 mm (FWHM) and good linearity were obtained. This is in good agreement with the theoretical calculations.

  20. Second Harmonic Generation Imaging Microscopy: Applications to Diseases Diagnostics

    Campagnola, Paul

    2011-01-01

    Second Harmonic Generation microscopy has emerged as a powerful new optical imaging modality. This Feature describes its chemical and physical principles and highlights current applications in disease diagnostics.

  1. 2D MEMS electrostatic cantilever waveguide scanner for potential image display application

    Gu Kebin

    2015-01-01

    Full Text Available This paper presents the current status of our micro-fabricated SU-8 2D electrostatic cantilever waveguide scanner. The current design utilizes a monolithically integrated electrostatic push-pull actuator. A 4.0 μm SU-8 rib waveguide design allows a relatively large core cross section (4μm in height and 20 μm in width to couple with existing optical fiber and a broad band single mode operation (λ= 0.7μm to 1.3μm with minimal transmission loss (85% to 87% output transmission efficiency with Gaussian beam profile input. A 2D scanning motion has been successfully demonstrated with two fundamental resonances found at 202 and 536 Hz in vertical and horizontal directions. A 130 μm and 19 μm, corresponding displacement and 0.062 and 0.009 rad field of view were observed at a +150V input. Beam divergence from the waveguide was corrected by a focusing GRIN lens and a 5μm beam diameter is observed at the focal plane. The transmission efficiency is low (~10% and cantilever is slightly under tensile residual stress due to inherent imperfection in the process and tooling in fabrication. However, 2D light scanning pattern was successfully demonstrated using 1-D push-pull actuation.

  2. LEAF AREA INDEX ESTIMATION IN VINEYARDS FROM UAV HYPERSPECTRAL DATA, 2D IMAGE MOSAICS AND 3D CANOPY SURFACE MODELS

    I. Kalisperakis; Stentoumis, Ch.; L. Grammatikopoulos; K. Karantzalos

    2015-01-01

    The indirect estimation of leaf area index (LAI) in large spatial scales is crucial for several environmental and agricultural applications. To this end, in this paper, we compare and evaluate LAI estimation in vineyards from different UAV imaging datasets. In particular, canopy levels were estimated from i.e., (i) hyperspectral data, (ii) 2D RGB orthophotomosaics and (iii) 3D crop surface models. The computed canopy levels have been used to establish relationships with the measured ...

  3. Echogenicity based approach to detect, segment and track the common carotid artery in 2D ultrasound images.

    Narayan, Nikhil S; Marziliano, Pina

    2015-08-01

    Automatic detection and segmentation of the common carotid artery in transverse ultrasound (US) images of the thyroid gland play a vital role in the success of US guided intervention procedures. We propose in this paper a novel method to accurately detect, segment and track the carotid in 2D and 2D+t US images of the thyroid gland using concepts based on tissue echogenicity and ultrasound image formation. We first segment the hypoechoic anatomical regions of interest using local phase and energy in the input image. We then make use of a Hessian based blob like analysis to detect the carotid within the segmented hypoechoic regions. The carotid artery is segmented by making use of least squares ellipse fit for the edge points around the detected carotid candidate. Experiments performed on a multivendor dataset of 41 images show that the proposed algorithm can segment the carotid artery with high sensitivity (99.6 ±m 0.2%) and specificity (92.9 ±m 0.1%). Further experiments on a public database containing 971 images of the carotid artery showed that the proposed algorithm can achieve a detection accuracy of 95.2% with a 2% increase in performance when compared to the state-of-the-art method. PMID:26736920

  4. Twin robotic x-ray system for 2D radiographic and 3D cone-beam CT imaging

    Fieselmann, Andreas; Steinbrener, Jan; Jerebko, Anna K.; Voigt, Johannes M.; Scholz, Rosemarie; Ritschl, Ludwig; Mertelmeier, Thomas

    2016-03-01

    In this work, we provide an initial characterization of a novel twin robotic X-ray system. This system is equipped with two motor-driven telescopic arms carrying X-ray tube and flat-panel detector, respectively. 2D radiographs and fluoroscopic image sequences can be obtained from different viewing angles. Projection data for 3D cone-beam CT reconstruction can be acquired during simultaneous movement of the arms along dedicated scanning trajectories. We provide an initial evaluation of the 3D image quality based on phantom scans and clinical images. Furthermore, initial evaluation of patient dose is conducted. The results show that the system delivers high image quality for a range of medical applications. In particular, high spatial resolution enables adequate visualization of bone structures. This system allows 3D X-ray scanning of patients in standing and weight-bearing position. It could enable new 2D/3D imaging workflows in musculoskeletal imaging and improve diagnosis of musculoskeletal disorders.

  5. Calibration model of a dual gain flat panel detector for 2D and 3D x-ray imaging

    The continuing research and further development in flat panel detector technology have led to its integration into more and more medical x-ray systems for two-dimensional (2D) and three-dimensional (3D) imaging, such as fixed or mobile C arms. Besides the obvious advantages of flat panel detectors, like the slim design and the resulting optimum accessibility to the patient, their success is primarily a product of the image quality that can be achieved. The benefits in the physical and performance-related features as opposed to conventional image intensifier systems (e.g., distortion-free reproduction of imaging information or almost linear signal response over a large dynamic range) can be fully exploited, however, only if the raw detector images are correctly calibrated and postprocessed. Previous procedures for processing raw data contain idealizations that, in the real world, lead to artifacts or losses in image quality. Thus, for example, temperature dependencies or changes in beam geometry, as can occur with mobile C arm systems, have not been taken into account up to this time. Additionally, adverse characteristics such as image lag or aging effects have to be compensated to attain the best possible image quality. In this article a procedure is presented that takes into account the important dependencies of the individual pixel sensitivity of flat panel detectors used in 2D or 3D imaging and simultaneously minimizes the work required for an extensive recalibration. It is suitable for conventional detectors with only one gain mode as well as for the detectors specially developed for 3D imaging with dual gain read-out technology

  6. Interpolated Compressed Sensing for 2D Multiple Slice Fast MR Imaging

    Yong Pang; Xiaoliang Zhang

    2013-01-01

    Sparse MRI has been introduced to reduce the acquisition time and raw data size by undersampling the k-space data. However, the image quality, particularly the contrast to noise ratio (CNR), decreases with the undersampling rate. In this work, we proposed an interpolated Compressed Sensing (iCS) method to further enhance the imaging speed or reduce data size without significant sacrifice of image quality and CNR for multi-slice two-dimensional sparse MR imaging in humans. This method utilizes...

  7. An Automatic Framework for Segmentation and Digital Inpainting of 2D Frontal Face Images

    Sobiecki, A.; Giraldi, G. A.; Neves, L. A. P.; Thomaz, C. E.

    2012-01-01

    Nowadays applications that use face images as input for people identification have been very common. In general, the input image must be preprocessed in order to fit some normalization and quality criteria. In this paper, we propose a computational framework composed of digital image quality computa

  8. Curve-based 2D-3D registration of coronary vessels for image guided procedure

    Duong, Luc; Liao, Rui; Sundar, Hari; Tailhades, Benoit; Meyer, Andreas; Xu, Chenyang

    2009-02-01

    3D roadmap provided by pre-operative volumetric data that is aligned with fluoroscopy helps visualization and navigation in Interventional Cardiology (IC), especially when contrast agent-injection used to highlight coronary vessels cannot be systematically used during the whole procedure, or when there is low visibility in fluoroscopy for partially or totally occluded vessels. The main contribution of this work is to register pre-operative volumetric data with intraoperative fluoroscopy for specific vessel(s) occurring during the procedure, even without contrast agent injection, to provide a useful 3D roadmap. In addition, this study incorporates automatic ECG gating for cardiac motion. Respiratory motion is identified by rigid body registration of the vessels. The coronary vessels are first segmented from a multislice computed tomography (MSCT) volume and correspondent vessel segments are identified on a single gated 2D fluoroscopic frame. Registration can be explicitly constrained using one or multiple branches of a contrast-enhanced vessel tree or the outline of guide wire used to navigate during the procedure. Finally, the alignment problem is solved by Iterative Closest Point (ICP) algorithm. To be computationally efficient, a distance transform is computed from the 2D identification of each vessel such that distance is zero on the centerline of the vessel and increases away from the centerline. Quantitative results were obtained by comparing the registration of random poses and a ground truth alignment for 5 datasets. We conclude that the proposed method is promising for accurate 2D-3D registration, even for difficult cases of occluded vessel without injection of contrast agent.

  9. Auto-masked 2D/3D image registration and its validation with clinical cone-beam computed tomography

    Image-guided alignment procedures in radiotherapy aim at minimizing discrepancies between the planned and the real patient setup. For that purpose, we developed a 2D/3D approach which rigidly registers a computed tomography (CT) with two x-rays by maximizing the agreement in pixel intensity between the x-rays and the corresponding reconstructed radiographs from the CT. Moreover, the algorithm selects regions of interest (masks) in the x-rays based on 3D segmentations from the pre-planning stage. For validation, orthogonal x-ray pairs from different viewing directions of 80 pelvic cone-beam CT (CBCT) raw data sets were used. The 2D/3D results were compared to corresponding standard 3D/3D CBCT-to-CT alignments. Outcome over 8400 2D/3D experiments showed that parametric errors in root mean square were <0.18° (rotations) and <0.73 mm (translations), respectively, using rank correlation as intensity metric. This corresponds to a mean target registration error, related to the voxels of the lesser pelvis, of <2 mm in 94.1% of the cases. From the results we conclude that 2D/3D registration based on sequentially acquired orthogonal x-rays of the pelvis is a viable alternative to CBCT-based approaches if rigid alignment on bony anatomy is sufficient, no volumetric intra-interventional data set is required and the expected error range fits the individual treatment prescription. (paper)

  10. Estimating elastic moduli of rocks from thin sections: Digital rock study of 3D properties from 2D images

    Saxena, Nishank; Mavko, Gary

    2016-03-01

    Estimation of elastic rock moduli using 2D plane strain computations from thin sections has several numerical and analytical advantages over using 3D rock images, including faster computation, smaller memory requirements, and the availability of cheap thin sections. These advantages, however, must be weighed against the estimation accuracy of 3D rock properties from thin sections. We present a new method for predicting elastic properties of natural rocks using thin sections. Our method is based on a simple power-law transform that correlates computed 2D thin section moduli and the corresponding 3D rock moduli. The validity of this transform is established using a dataset comprised of FEM-computed elastic moduli of rock samples from various geologic formations, including Fontainebleau sandstone, Berea sandstone, Bituminous sand, and Grossmont carbonate. We note that using the power-law transform with a power-law coefficient between 0.4-0.6 contains 2D moduli to 3D moduli transformations for all rocks that are considered in this study. We also find that reliable estimates of P-wave (Vp) and S-wave velocity (Vs) trends can be obtained using 2D thin sections.