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Sample records for radiography facilities otimizacao

  1. PROTON RADIOGRAPHY FOR AN ADVANCED HYDROTEST FACILITY

    SciTech Connect

    C. MORRIS

    2000-11-01

    Analysis of data from BNL experiment 933 is presented. Results demonstrate that proton radiography can meet many of the requirements for an Advanced Hydrotest Facility (AHF). Results for background, position resolution, metrology, quantitative radiography, material identification, and edge resolution are presented.

  2. Neutron radiography at the NRAD facility

    SciTech Connect

    McClellan, G.C.; Richards, W.J.

    1984-01-01

    The NRAD facility uses a 150 kW TRIGA reactor as a source of neutrons and is integrated with a hot cell such that highly radioactive specimens can be radiographed without removing them from the hot cell environment. A second beam tube is located in a separate shielded addition to HFEF and permits neutron radiography of irradiated or unirradiated specimens without subjecting them to the alpha-contaminated hot cell environment. Both beams are optimized for neutron radiography of highly radioactive nuclear fuels. Techniques for using these facilities are described. Advantages include: the ability to perform thermal and epithermal neutron radiography on specimens either inside or outside the hot cell, lack of competition for the use of the reactor, versatility of facility design, and the addition of neutron tomography. (LEW)

  3. Hot Fuel Examination Facility's neutron radiography reactor

    SciTech Connect

    Pruett, D.P.; Richards, W.J.; Heidel, C.C.

    1983-01-01

    Argonne National Laboratory-West is located near Idaho Falls, Idaho, and is operated by the University of Chicago for the United States Department of Energy in support of the Liquid Metal Fast Breeder Reactor Program, LMFBR. The Hot Fuel Examination Facility, HFEF, is one of several facilities located at the Argonne Site. HFEF comprises a large hot cell where both nondestructive and destructive examination of highly-irradiated reactor fuels are conducted in support of the LMFBR program. One of the nondestructive examination techniques utilized at HFEF is neutron radiography, which is provided by the NRAD reactor facility (a TRIGA type reactor) below the HFEF hot cell.

  4. Optical velocimetry at the Los Alamos Proton Radiography Facility

    NASA Astrophysics Data System (ADS)

    Tupa, Dale; Tainter, Amy; Neukirch, Levi; Hollander, Brian; Buttler, William; Holtkamp, David; The Los Alamos Proton Radiography Team Team

    2016-05-01

    The Los Alamos Proton Radiography Facility (pRad) employs a high-energy proton beam to image the properties and behavior of materials driven by high explosives. We will discuss features of pRad and describe some recent experiments, highlighting optical diagnostics for surface velocity measurements.

  5. Neutron radiography and tomography facility at IBR-2 reactor

    NASA Astrophysics Data System (ADS)

    Kozlenko, D. P.; Kichanov, S. E.; Lukin, E. V.; Rutkauskas, A. V.; Belushkin, A. V.; Bokuchava, G. D.; Savenko, B. N.

    2016-05-01

    An experimental station for investigations using neutron radiography and tomography was developed at the upgraded high-flux pulsed IBR-2 reactor. The 20 × 20 cm neutron beam is formed by the system of collimators with the characteristic parameter L/D varying from 200 to 2000. The detector system is based on a 6LiF/ZnS scintillation screen; images are recorded using a high-sensitivity video camera based on the high-resolution CCD matrix. The results of the first neutron radiography and tomography experiments at the developed facility are presented.

  6. Beam Characterization at the Neutron Radiography Facility

    SciTech Connect

    Sarah Morgan; Jeffrey King

    2013-01-01

    The quality of a neutron imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam’s effective length-to-diameter ratio, neutron flux profile, energy spectrum, image quality, and beam divergence, is vital for producing quality radiographic images. This project characterized the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam’s effective length-to-diameter ratio and image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. Improvement of the existing NRAD MCNP beamline model includes validation of the model’s energy spectrum and the development of enhanced image simulation methods. The image simulation methods predict the radiographic image of an object based on the foil reaction rate data obtained by placing a model of the object in front of the image plane in an MCNP beamline model.

  7. Radiography Facility - Building 239 Independent Validation Review

    SciTech Connect

    Altenbach, T J; Beaulieu, R A; Watson, J F; Wong, H J

    2010-02-02

    The purpose of this task was to perform an Independent Validation Review to evaluate the successful implementation and effectiveness of Safety Basis controls, including new and revised controls, to support the implementation of a new DSA/TSR for B239. This task addresses Milestone 2 of FY10 PEP 7.6.6. As the first IVR ever conducted on a LLNL nuclear facility, it was designated a pilot project. The review follows the outline developed for Milestone 1 of the PEP, which is based on the DOE Draft Guide for Performance of Independent Verification Review of Safety Basis Controls. A formal Safety Basis procedure will be developed later, based on the lessons learned with this pilot project. Note, this review is termed a ''Validation'' in order to be consistent with the PEP definition and address issues historically raised about verification mechanisms at LLNL. Validation is intended to confirm that implementing mechanisms realistically establish the ability of TSR LCO, administrative control or safety management program to accomplish its intended safety function and that the controls are being implemented. This effort should not, however, be confused with a compliance assessment against all relevant DOE requirements and national standards. Nor is it used as a vehicle to question the derivation of controls already approved by LSO unless a given TSR statement simply cannot be implemented as stated.

  8. Radiography

    NASA Technical Reports Server (NTRS)

    Gardner, C. G.

    1973-01-01

    Radiography is discussed as a method for nondestructive evaluation of internal flaws of solids. Gamma ray and X-ray equipment are described along with radiographic film, radiograph interpretation, and neutron radiography.

  9. Technical Specifications for the Neutron Radiography Facility (TRIGA Mark 1 Reactor). Revision 6

    SciTech Connect

    Tomlinson, R.L.; Perfect, J.F.

    1988-04-01

    These Technical Specifications state the limits under which the Neutron Radiography Facility, with its associated TRIGA Mark I Reactor, is operated by the Westinghouse Hanford Company for the US Department of Energy. These specifications cover operation of the Facility for the purpose of examination of specimens (including contained fissile material) by neutron radiography, for the irradiation of specimens in the pneumatic transfer system and approved in-core or in-pool irradiation facilities and operator training. The Final Safety Analysis Report (TC-344) and its supplements, and these Technical Specifications are the basic safety documents of the Neutron Radiography Facility.

  10. Design Verification Report Neutron Radiography Facility (NRF) TRIGA Fuel Storage Systems

    SciTech Connect

    CARRELL, R.D.

    2002-01-31

    This report outlines the methods, procedures, and outputs developed during the Neutron Radiography Facility (NRF) Training, Research and Isotope Production, General Atomics (TRIGA) fuel storage system design and fabrication.

  11. Neutron Radiography Facility at IBR-2 High Flux Pulsed Reactor: First Results

    NASA Astrophysics Data System (ADS)

    Kozlenko, D. P.; Kichanov, S. E.; Lukin, E. V.; Rutkauskas, A. V.; Bokuchava, G. D.; Savenko, B. N.; Pakhnevich, A. V.; Rozanov, A. Yu.

    A neutron radiography and tomography facilityhave been developed recently at the IBR-2 high flux pulsed reactor. The facility is operated with the CCD-camera based detector having maximal field of view of 20x20 cm, and the L/D ratio can be varied in the range 200 - 2000. The first results of the radiography and tomography experiments with industrial materials and products, paleontological and geophysical objects, meteorites, are presented.

  12. Proposed power upgrade of the Hot Fuel Examination Facility's neutron radiography reactor. [NRAD reactor

    SciTech Connect

    Pruett, D.P.; Richards, W.J.; Heidel, C.C.

    1984-01-01

    The Hot Fuel Examination Facility, HFEF, is one of several facilities located at the Argonne Site. HFEF comprises a large hot cell where both non-destructive and destructive examination of highly-irradiated reactor fuels are conducted in support of the LMFBR program. One of the non-destructive examination techniques utilized at HFEF is neutron radiography. Neutron radiography is provided by the NRAD reactor facility, which is located beneath the HFEF hot cell. The NRAD reactor is a TRIGA reactor and is operated at a steady state power level of 250 kW solely for neutron radiography and the development of radiography techniques. When the NRAD facility was designed and constructed, an operating power level of 250 kW was considered to be adequate for obtaining radiographs of the type of specimens envisaged at that time. A typical radiograph required approximately a twenty-minute exposure time. Specimens were typically single fuel rods placed in an aluminum tray. Since that time, however, several things have occurred that have tended to increase radiography exposure times to as much as 90 minutes each. In order to decrease exposure times, the reactor power level is to be increased from 250 kw to 1 MW. This increase in power will necessitate several engineering and design changes. These changes are described.

  13. Industrial applications at the new cold neutron radiography and tomography facility of the HMI

    NASA Astrophysics Data System (ADS)

    Kardjilov, N.; Hilger, A.; Manke, I.; Strobl, M.; Treimer, W.; Banhart, J.

    2005-04-01

    The new cold neutron radiography and tomography facility at the Hahn-Meitner-Institut Berlin is suited for the investigation of components and materials from different industrial fields. The high-flux measuring position of the facility allows real-time imaging of fast dynamical processes. Cold neutrons interact stronger with the matter compared to thermal neutrons, which leads to a much better radiography contrast. Some examples of different industry applications like investigations on discharging of a Lithium battery or on oil sediments in a vent pipe are presented.

  14. Evaluation of dynamic target options for dual axis radiography hydrotest facility II (DARHT II) and advanced hydrotest facility (AHF) programs

    SciTech Connect

    Krogh, M; Neurath, R; Sampayan, S; Sanders, D

    1999-03-01

    Initial results indicate that electron beams hitting targets used to generate x-rays during multipulse operation in advanced radiography facilities will generate plasma plumes which will disturb the electron beam during subsequent pulses. This, in turn, degrades the x-ray spot quality generated by the subsequent pulses. If this concern is substantiated, new facilities such as the Dual Axia Radiography Hydrotest Facility (DARHT II) and the Advanced Hydrotest Facility (AHF) will need a provision for mitigating this effect. one such provision involves moving the target with sufficient velocity that any plasmas formed are carried adequately far from the electron beam that they do not disturb it. They report the various approaches which have been considered and present data showing the maximum target rates which can be achieved with each approach.

  15. First steps towards real-time radiography at the NECTAR facility

    NASA Astrophysics Data System (ADS)

    Bücherl, T.; Wagner, F. M.; v. Gostomski, Ch. Lierse

    2009-06-01

    The beam tube SR10 at Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II) provides an intense beam of fission neutrons for medical application (MEDAPP) and for radiography and tomography of technical and other objects (NECTAR). The high neutron flux of up to 9.8E+07 cm -2 s -1 (depending on filters and collimation) with a mean energy of about 1.9 MeV at the sample position at the NECTAR facility prompted an experimental feasibility study to investigate the potential for real-time (RT) radiography.

  16. Streaked radiography of an irradiated foam sample on the National Ignition Facility

    SciTech Connect

    Cooper, A. B. R.; Schneider, M. B.; MacLaren, S. A.; Young, P. E.; Hsing, W. W.; Seugling, R.; Foord, M. E.; Sain, J. D.; May, M. J.; Marrs, R. E.; Maddox, B. R.; Lu, K.; Dodson, K.; Smalyuk, V.; Moore, A. S.; Graham, P.; Foster, J. M.; Back, C. A.; Hund, J. F.

    2013-03-15

    Streaked x-ray radiography images of annular patterns in an evolving tantalum oxide foam under the influence of a driven, subsonic radiation wave were obtained on the National Ignition Facility. This is the first successful radiography measurement of the evolution of well-defined foam features under a driven, subsonic wave in the diffusive regime. A continuous record of the evolution was recorded on an x-ray streak camera, using a slot-apertured point-projection backlighter with an 8 ns nickel source (7.9 keV). Radiography images were obtained for four different annular patterns, which were corrected using a source-dependent flat-field image. The evolution of the foam features was well-modeled using the 3D KULL radiation hydrodynamics code. This experimental and modeling platform can be modified for scaled high-energy-density laboratory astrophysics experiments.

  17. Neutron transport study of a beam port based dynamic neutron radiography facility

    NASA Astrophysics Data System (ADS)

    Khaial, Anas M.

    Neutron radiography has the ability to differentiate between gas and liquid in two-phase flow due both to the density difference and the high neutron scattering probability of hydrogen. Previous studies have used dynamic neutron radiography -- in both real-time and high-speed -- for air-water, steam-water and gas-liquid metal two-phase flow measurements. Radiography with thermal neutrons is straightforward and efficient as thermal neutrons are easier to detect with relatively higher efficiency and can be easily extracted from nuclear reactor beam ports. The quality of images obtained using neutron radiography and the imaging speed depend on the neutron beam intensity at the imaging plane. A high quality neutron beam, with thermal neutron intensity greater than 3.0x 10 6 n/cm2-s and a collimation ratio greater than 100 at the imaging plane, is required for effective dynamic neutron radiography up to 2000 frames per second. The primary objectives of this work are: (1) to optimize a neutron radiography facility for dynamic neutron radiography applications and (2) to investigate a new technique for three-dimensional neutron radiography using information obtained from neutron scattering. In this work, neutron transport analysis and experimental validation of a dynamic neutron radiography facility is studied with consideration of real-time and high-speed neutron radiography requirements. A beam port based dynamic neutron radiography facility, for a target thermal neutron flux of 1.0x107 n/cm2-s, has been analyzed, constructed and experimentally verified at the McMaster Nuclear Reactor. The neutron source strength at the beam tube entrance is evaluated experimentally by measuring the thermal and fast neutron fluxes using copper activation flux-mapping technique. The development of different facility components, such as beam tube liner, gamma ray filter, beam shutter and biological shield, is achieved analytically using neutron attenuation and divergence theories. Monte

  18. UGCT: New X-ray radiography and tomography facility

    NASA Astrophysics Data System (ADS)

    Masschaele, B. C.; Cnudde, V.; Dierick, M.; Jacobs, P.; Van Hoorebeke, L.; Vlassenbroeck, J.

    2007-09-01

    The UGCT (University Gent Computer Tomography) facility, a cooperation between the Radiation Physics research group and the Sedimentary Geology and Engineering Geology research group is a new CT facility providing a large range of scanning possibilities. Formerly a Skyscan 1072 was used to perform X-ray micro-CT scans at the UGCT facility and although this is a very powerful instrument, there were needs for a higher resolution and more flexibility. Therefore, the UCGT facility started the construction of a multidisciplinary micro-CT scanner inside a shielded room with a maximum flexibility of the set-up. The X-ray tube of this high-resolution CT scanner is a state-of-the-art open-type device with dual head: one head for high power micro-CT and one for sub-micro- or also called nano-CT. An important advantage of this scanner is that different detectors can be used to optimize the scanning conditions of the objects under investigation. The entire set-up is built on a large optical table to obtain the highest possible stability. Due to the flexible set-up and the powerful CT reconstruction software "Octopus", it is possible to obtain the highest quality and the best signal-to-noise of the reconstructed images for each type of sample.

  19. Documented Safety Analysis Addendum for the Neutron Radiography Reactor Facility Core Conversion

    SciTech Connect

    Boyd D. Christensen

    2009-05-01

    The Neutron Radiography Reactor Facility (NRAD) is a Training, Research, Isotope Production, General Atomics (TRIGA) reactor which was installed in the Idaho National Laboratory (INL) Hot Fuels Examination Facility (HFEF) at the Materials and Fuels Complex (MFC) in the mid 1970s. The facility provides researchers the capability to examine both irradiated and non-irradiated materials in support of reactor fuel and components programs through non-destructive neutron radiography examination. The facility has been used in the past as one facet of a suite of reactor fuels and component examination facilities available to researchers at the INL and throughout the DOE complex. The facility has also served various commercial research activities in addition to the DOE research and development support. The reactor was initially constructed using Fuel Lifetime Improvement Program (FLIP)- type highly enriched uranium (HEU) fuel obtained from the dismantled Puerto Rico Nuclear Center (PRNC) reactor. In accordance with international non-proliferation agreements, the NRAD core will be converted to a low enriched uranium (LEU) fuel and will continue to utilize the PRNC control rods, control rod drives, startup source, and instrument console as was previously used with the HEU core. The existing NRAD Safety Analysis Report (SAR) was created and maintained in the preferred format of the day, combining sections of both DOE-STD-3009 and Nuclear Regulatory Commission Regulatory Guide 1.70. An addendum was developed to cover the refueling and reactor operation with the LEU core. This addendum follows the existing SAR format combining required formats from both the DOE and NRC. This paper discusses the project to successfully write a compliant and approved addendum to the existing safety basis documents.

  20. Upgrading the Neutron Radiography Facility in South Africa (SANRAD): Concrete Shielding Design Characteristics

    NASA Astrophysics Data System (ADS)

    de Beer, F. C.; Radebe, M. J.; Schillinger, B.; Nshimirimana, R.; Ramushu, M. A.; Modise, T.

    A common denominator of all neutron radiography (NRAD) facilities worldwide is that the perimeter of the experimental chamber of the facility is a radiation shielding structure which,in some cases, also includes flight tube and filter chamber structures. These chambers are normally both located on the beam port floor outside the biological shielding of the neutron source. The main function of the NRAD-shielding structure isto maintain a radiological safe working environment in the entire beam hall according to standards set by individual national radiological safety regulations. In addition, the shielding's integrity and capability should not allow, during NRAD operations, an increase in radiation levels in the beam port hall and thus negatively affectadjacent scientific facilities (e.g. neutron diffraction facilities).As a bonus, the shielding for the NRAD facility should also prevent radiation scattering towards the detector plane and doing so, thus increase thecapability of obtaining better quantitative results. This paper addresses Monte Carlo neutron-particletransport simulations to theoretically optimize the shielding capabilities of the biological barrierfor the SANRAD facility at the SAFARI-1 nuclear research reactor in South Africa. The experimental process to develop the shielding, based on the principles of the ANTARES facility, is described. After casting, the homogeneity distribution of these concrete mix materials is found to be near perfect and first order experimental radiation shielding characteristicsthrough film badge (TLD) exposure show acceptable values and trends in neutron- and gamma-ray attenuation.

  1. Scientific Design of the New Neutron Radiography Facility (SANRAD) at SAFARI-1 for South Africa

    NASA Astrophysics Data System (ADS)

    de Beer, F. C.; Gruenauer, F.; Radebe, J. M.; Modise, T.; Schillinger, B.

    The final scientific design for an upgraded neutron radiography/tomography facility at beam port no.2 of the SAFARI-1 nuclear research reactor has been performed through expert advice from Physics Consulting, FRMII in Germany and IPEN, Brazil. A need to upgrade the facility became apparent due to the identification of various deficiencies of the current SANRAD facility during an IAEA-sponsored expert mission of international scientists to Necsa, South Africa. A lack of adequate shielding that results in high neutron background on the beam port floor, a mismatch in the collimator aperture to the core that results in a high gradient in neutron flux on the imaging plane and due to a relative low L/D the quality of the radiographs are poor, are a number of deficiencies to name a few.The new design, based on results of Monte Carlo (MCNP-X) simulations of neutron- and gamma transport from the reactor core and through the new facility, is being outlined. The scientific design philosophy, neutron optics and imaging capabilities that include the utilization of fission neutrons, thermal neutrons, and gamma-rays emerging from the core of SAFARI-1 are discussed.

  2. 2D X-ray radiography of imploding capsules at the national ignition facility.

    PubMed

    Rygg, J R; Jones, O S; Field, J E; Barrios, M A; Benedetti, L R; Collins, G W; Eder, D C; Edwards, M J; Kline, J L; Kroll, J J; Landen, O L; Ma, T; Pak, A; Peterson, J L; Raman, K; Town, R P J; Bradley, D K

    2014-05-16

    First measurements of the in-flight shape of imploding inertial confinement fusion (ICF) capsules at the National Ignition Facility (NIF) were obtained by using two-dimensional x-ray radiography. The sequence of area-backlit, time-gated pinhole images is analyzed for implosion velocity, low-mode shape and density asymmetries, and the absolute offset and center-of-mass velocity of the capsule shell. The in-flight shell is often observed to be asymmetric even when the concomitant core self-emission is round. A ∼ 15 μm shell asymmetry amplitude of the Y(40) spherical harmonic mode was observed for standard NIF ICF hohlraums at a shell radius of ∼ 200 μm (capsule at ∼ 5× radial compression). This asymmetry is mitigated by a ∼ 10% increase in the hohlraum length. PMID:24877944

  3. Improvements in the Image Quality of Neutron Radiograms of NUR Neutron Radiography Facility by Using Several Exposure Techniques

    NASA Astrophysics Data System (ADS)

    Zergoug, T.; Nedjar, A.; Mokeddem, M. Y.; Mammou, L.

    2008-03-01

    Since the construction of NUR reactor neutron radiography facility in 1991, only transfer exposure method was used as a non destructive technique. The reason is the excess of gamma rays in the neutron beam. To improve radiation performances of the NR system, a stainless steal hollow conical cylinder is introduced at the bottom of the facility beam port, this filter reduce gamma infiltration through the edges of the NR structure without disturbing neutron beam arriving from the in pool divergent collimator. First results confirm our prediction; a gamma rays diminution and a relatively stable neutron flux at the point object are confirmed, consequently the n/γ ratio reaches a value of 2.104 n/cm2 mR. Radiograms obtained by using the direct exposure method reveal the feasibility of the technique in the new NR configuration facility, but a weak resolution and contrast of the image is observed. In this paper, we describe a procedure to improve the image quality obtained by direct exposure technique. The process consists of using digitized images obtained by several exposure techniques (NR, gamma radiography or X radiography) for a comparison study and then better image definition can be attained.

  4. Improvements in the Image Quality of Neutron Radiograms of NUR Neutron Radiography Facility by Using Several Exposure Techniques

    SciTech Connect

    Zergoug, T.; Nedjar, A.; Mokeddem, M. Y.; Mammou, L.

    2008-03-17

    Since the construction of NUR reactor neutron radiography facility in 1991, only transfer exposure method was used as a non destructive technique. The reason is the excess of gamma rays in the neutron beam. To improve radiation performances of the NR system, a stainless steal hollow conical cylinder is introduced at the bottom of the facility beam port, this filter reduce gamma infiltration through the edges of the NR structure without disturbing neutron beam arriving from the in pool divergent collimator. First results confirm our prediction; a gamma rays diminution and a relatively stable neutron flux at the point object are confirmed, consequently the n/{gamma} ratio reaches a value of 2.104 n/cm{sup 2} mR. Radiograms obtained by using the direct exposure method reveal the feasibility of the technique in the new NR configuration facility, but a weak resolution and contrast of the image is observed. In this paper, we describe a procedure to improve the image quality obtained by direct exposure technique. The process consists of using digitized images obtained by several exposure techniques (NR, gamma radiography or X radiography) for a comparison study and then better image definition can be attained.

  5. AIRIX: an induction accelerator facility developed at CEA for flash radiography in detonics

    NASA Astrophysics Data System (ADS)

    Cavailler, Claude

    1999-06-01

    AIRIX is an induction linear accelerator which will be used for flash radiography in CEA/DAM. Designed to produce an X-ray dose of more than 500 Rads at 1 meter with an X-ray focal spot size diameter of less than 2 mm (LANL-CEA DAM definition), this facility consists in a 4 MeV/3.5 kA pulsed electron injector and 16 MeV induction accelerator powered by 32 high voltage generators. A prototype of this accelerator, called PIVAIR, has been studied and realized in CEA CESTA near Bordeaux. PIVAIR is a validation step for AIRIX at 8 MeV. It includes an injector (4 MeV, 3.5 kA, 60 ns) and 16 inductor cells supplied by 8 high voltage generators (250 kV, 70 ns). Two different technologies of induction cells have been tested (rexolite insulator or ferrite under vacuum). We have chosen ferrite under vacuum cells technology after comparison of results on beam transport and reliability tests. A focusing experiment at 7.2 MeV of the electron beam as been achieved during summer 1997. We have begun to produce X-rays in October 1997. A dose level of 50 Rad at 1 meter has been achieved with an X-ray spot size diameter of 3.5 to 4 mm (LANL-CEA DAM definition). Static flash radiography of very dense object have been achieved from November 97 until February 98. We have been able to test in situ new kinds of very high sensitive X- ray detectors and to check they had reached our very ambitious goals: (1) quantum efficiency at 5 MeV greater than 50% instead of 1% for luminous screens and film; (2) sensitivity less than 10 (mu) Rad (100 time more sensitive than radiographic luminous screens and films); (3) dynamic range greater than 100; (4) resolution less than 2 mm. We will present in this communication brand new kinds of detection systems, called high stopping power detectors, such as: (1) (gamma) camera with segmented thick crystal of BGO and MCP image intensifier; (2) multistep parallel plate avalanche chamber; (3) pixellized CdTe MeV photoconductor matrix. AIRIX accelerator is being

  6. 8. VIEW OF RADIOGRAPHY EQUIPMENT, TEST METHODS INCLUDED RADIOGRAPHY AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF RADIOGRAPHY EQUIPMENT, TEST METHODS INCLUDED RADIOGRAPHY AND BETA BACKSCATTERING. (7/13/56) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

  7. Neutron collimator design of neutron radiography based on the BNCT facility

    NASA Astrophysics Data System (ADS)

    Yang, Xiao-Peng; Yu, Bo-Xiang; Li, Yi-Guo; Peng, Dan; Lu, Jin; Zhang, Gao-Long; Zhao, Hang; Zhang, Ai-Wu; Li, Chun-Yang; Liu, Wan-Jin; Hu, Tao; Lü, Jun-Guang

    2014-02-01

    For the research of CCD neutron radiography, a neutron collimator was designed based on the exit of thermal neutron of the Boron Neutron Capture Therapy (BNCT) reactor. Based on the Geant4 simulations, the preliminary choice of the size of the collimator was determined. The materials were selected according to the literature data. Then, a collimator was constructed and tested on site. The results of experiment and simulation show that the thermal neutron flux at the end of the neutron collimator is greater than 1.0×106 n/cm2/s, the maximum collimation ratio (L/D) is 58, the Cd-ratio(Mn) is 160 and the diameter of collimator end is 10 cm. This neutron collimator is considered to be applicable for neutron radiography.

  8. 42 CFR 37.44 - Approval of radiographic facilities that use digital radiography systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS SPECIFICATIONS FOR MEDICAL EXAMINATIONS OF COAL... facility approval. (1) Facilities seeking approval must demonstrate the ability to make high quality... radiographic image files from six or more sample chest radiographs that are of acceptable quality to one...

  9. An 800-MeV proton radiography facility for dynamic experiments

    SciTech Connect

    King, N.S.P.; Adams, K.; Ables, E.

    1998-12-01

    The capability has been successfully developed at the Los Alamos Nuclear Science Center (LANSCE) to utilize a spatially and temporally prepared 800-MeV proton beam to produce proton radiographs. A series of proton bursts are transmitted through a dynamically varying object and transported, via a unique magnetic lens system, to an image plane. The magnetic lens system permits correcting for the effects of multiple coulomb scattering which would otherwise completely blur the spatially transmitted information at the image plane. The proton radiographs are recorded on either a time integrating film plate or with a recently developed multi-frame electronic imaging camera system. The latter technique permits obtaining a time dependent series of proton radiographs with time intervals (modulo 358 ns) up to many microseconds and variable time intervals between images. One electronically shuttered, intensified, CCD camera is required per image. These cameras can detect single protons interacting with a scintillating fiber optic array in the image plane but also have a dynamic range which permits recording radiographs with better than 5% statistics for observation of detailed density variations in the object. A number of tests have been carried out to characterize the quality of the proton radiography system for absolute mass determination, resolution, and dynamic range. Initial dynamic experiments characterized the temporal and spatial behavior of shock propagation in high explosives with up to six images per experiment. Based on experience with the prototype system, a number of upgrades are being implemented including the anticipated capability for enhanced mass discrimination through differential multiple coulomb scattering radiographs and more images with improved imaging techniques.

  10. Explosively driven two-shockwave tools with application to ejecta formation at the Los Alamos National Laboratory Proton Radiography Facility

    NASA Astrophysics Data System (ADS)

    Buttler, William

    2013-06-01

    We present the development of an explosively driven physics tool to generate two mostly uniaxial shockwaves. The tool is being used to extend single shockwave ejecta models to a subsequent shockwave event separated by a time interval on the order of a few microseconds. We explore the possibility of varying the amplitude of both the first and second shockwaves, and we apply the tool in experimental geometries on Sn with a surface roughness of Ra = 0 . 8 μ m. We then evaluate the tool further at the Los Alamos National Laboratory Proton Radiography (pRad) Facility in an application to Sn with larger scale perturbations of wavelength 550 μ m, and various amplitudes that gave wave-number amplitude products of η0 2 π / λ = { 3 / 4 , 1 / 2 , 1 / 4 , 1 / 8 } , where the perturbation amplitude is η0, and the wave-number k = 2 π / λ . The pRad data and velocimetry imply it should be possible to develop a second shock ejecta model based on unstable Richtmyer-Meshkov physics. In collaboration with David Oro, Fesseha Mariam, Alexander Saunders, Malcolm Andrews, Frank Cherne, James Hammerberg. Robert Hixson, Christopher Morris, Russell Olson, Dean Preston, Joseph Stone, Dale Tupa, and Wendy Vogan-McNeil, Los Alamos National Laboratory,

  11. High energy neutron radiography

    SciTech Connect

    Gavron, A.; Morley, K.; Morris, C.; Seestrom, S.; Ullmann, J.; Yates, G.; Zumbro, J.

    1996-06-01

    High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. The authors discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos.

  12. Development of a short duration backlit pinhole for radiography on the National Ignition Facility

    SciTech Connect

    Huntington, C. M.; Krauland, C. M.; Kuranz, C. C.; Drake, R. P.; Park, H.-S.; Kalantar, D. H.; Maddox, B. R.; Remington, B. A.; Kline, J.

    2010-10-15

    Experiments on the National Ignition Facility (NIF) will require bright, short duration, near-monochromatic x-ray backlighters for radiographic diagnosis of many high-energy density systems. This paper details a vanadium pinhole backlighter producing (1.8{+-}0.5)x10{sup 15} x-ray photons into 4{pi} sr near the vanadium He-like characteristic x-ray energy of 5.18 keV. The x-ray yield was quantified from a set of Ross filters imaged to a calibrated image plate, with the Dante diagnostic used to confirm the quasimonochromatic nature of the spectrum produced. Additionally, an x-ray film image shows a source-limited image resolution of 26 {mu}m from a 20 {mu}m diameter pinhole.

  13. The New Cold Neutron Radiography Facility (CNRF) at the Mianyang Research Reactor of the China Academy of Engineering Physics

    NASA Astrophysics Data System (ADS)

    Bin, Tang; Heyong, Huo; Ke, Tang; Rogers, John; Haste, Martin; Christodoulou, Marios

    A new cold neutron radiography beamline has been designed and constructed for the Mianyang reactor at the Institute of Nuclear Physics and Chemistry of the China Academy of Engineering Physics. This paper describes the components of the system and demonstrates the achievable image resolution.

  14. Digital radiography.

    PubMed

    Mattoon, J S

    2006-01-01

    Digital radiography has been used in human medical imaging since the 1980s with recent and rapid acceptance into the veterinary profession. Using advanced image capture and computer technology, radiographic images are viewed on a computer monitor. This is advantageous because radiographic images can be adjusted using dedicated computer software to maximize diagnostic image quality. Digital images can be accessed at computer workstations throughout the hospital, instantly retrieved from computer archives, and transmitted via the internet for consultation or case referral. Digital radiographic data can also be incorporated into a hospital information system, making record keeping an entirely paperless process. Digital image acquisition is faster when compared to conventional screen-film radiography, improving workflow and patient throughput. Digital radiography greatly reduces the need for 'retake' radiographs because of wide latitude in exposure factors. Also eliminated are costs associated with radiographic film and x-ray film development. Computed radiography, charged coupled devices, and flat panel detectors are types of digital radiography systems currently available. PMID:16971994

  15. Skull Radiography

    MedlinePlus

    What you need to know about… Skull Radiography X-ray images of the skull are taken when it is necessary to see the cranium, facial bones or jaw bones. ... Among other things, x-ray exams of the skull can show fractures. Patient Preparation Before the examination, ...

  16. Endodontic radiography.

    PubMed

    Nixon, P P; Robinson, P B

    1997-05-01

    The ability to take radiographs of good diagnostic quality is an essential prerequisite for successful root canal therapy. However, the operator also has a responsibility to limit the radiation dose to the patient. This article reviews the radiography required for root canal treatment with these criteria in mind. PMID:9515363

  17. Flash Proton Radiography

    NASA Astrophysics Data System (ADS)

    Merrill, Frank E.

    Protons were first investigated as radiographic probes as high energy proton accelerators became accessible to the scientific community in the 1960s. Like the initial use of X-rays in the 1800s, protons were shown to be a useful tool for studying the contents of opaque materials, but the electromagnetic charge of the protons opened up a new set of interaction processes which complicated their use. These complications in combination with the high expense of generating protons with energies high enough to penetrate typical objects resulted in proton radiography becoming a novelty, demonstrated at accelerator facilities, but not utilized to their full potential until the 1990s at Los Alamos. During this time Los Alamos National Laboratory was investigating a wide range of options, including X-rays and neutrons, as the next generation of probes to be used for thick object flash radiography. During this process it was realized that the charge nature of the protons, which was the source of the initial difficulty with this idea, could be used to recover this technique. By introducing a magnetic imaging lens downstream of the object to be radiographed, the blur resulting from scattering within the object could be focused out of the measurements, dramatically improving the resolution of proton radiography of thick systems. Imaging systems were quickly developed and combined with the temporal structure of a proton beam generated by a linear accelerator, providing a unique flash radiography capability for measurements at Los Alamos National Laboratory. This technique has now been employed at LANSCE for two decades and has been adopted around the world as the premier flash radiography technique for the study of dynamic material properties.

  18. An in-flight radiography platform to measure hydrodynamic instability growth in inertial confinement fusion capsules at the National Ignition Facility

    SciTech Connect

    Raman, K. S.; Smalyuk, V. A.; Casey, D. T.; Haan, S. W.; Hurricane, O. A.; Kroll, J. J.; Peterson, J. L.; Remington, B. A.; Robey, H. F.; Clark, D. S.; Hammel, B. A.; Landen, O. L.; Marinak, M. M.; Munro, D. H.; Salmonson, J.; Hoover, D. E.; Nikroo, A.; Peterson, K. J.

    2014-07-15

    A new in-flight radiography platform has been established at the National Ignition Facility (NIF) to measure Rayleigh–Taylor and Richtmyer–Meshkov instability growth in inertial confinement fusion capsules. The platform has been tested up to a convergence ratio of 4. An experimental campaign is underway to measure the growth of pre-imposed sinusoidal modulations of the capsule surface, as a function of wavelength, for a pair of ignition-relevant laser drives: a “low-foot” drive representative of what was fielded during the National Ignition Campaign (NIC) [Edwards et al., Phys. Plasmas 20, 070501 (2013)] and the new high-foot [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014)] pulse shape, for which the predicted instability growth is much lower. We present measurements of Legendre modes 30, 60, and 90 for the NIC-type, low-foot, drive, and modes 60 and 90 for the high-foot drive. The measured growth is consistent with model predictions, including much less growth for the high-foot drive, demonstrating the instability mitigation aspect of this new pulse shape. We present the design of the platform in detail and discuss the implications of the data it generates for the on-going ignition effort at NIF.

  19. Digital Radiography

    NASA Technical Reports Server (NTRS)

    1986-01-01

    System One, a digital radiography system, incorporates a reusable image medium (RIM) which retains an image. No film is needed; the RIM is read with a laser scanner, and the information is used to produce a digital image on an image processor. The image is stored on an optical disc. System allows the radiologist to "dial away" unwanted images to compare views on three screens. It is compatible with existing equipment and cost efficient. It was commercialized by a Stanford researcher from energy selective technology developed under a NASA grant.

  20. Electron radiography

    SciTech Connect

    Merrill, Frank E.; Morris, Christopher

    2005-05-17

    A system capable of performing radiography using a beam of electrons. Diffuser means receive a beam of electrons and diffuse the electrons before they enter first matching quadrupoles where the diffused electrons are focused prior to the diffused electrons entering an object. First imaging quadrupoles receive the focused diffused electrons after the focused diffused electrons have been scattered by the object for focusing the scattered electrons. Collimator means receive the scattered electrons and remove scattered electrons that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered electrons and refocus the collimated scattered electrons and map the focused collimated scattered electrons to transverse locations on an image plane representative of the electrons' positions in the object.

  1. INDUSTRIAL RADIOGRAPHY INSTRUCTOR'S GUIDE.

    ERIC Educational Resources Information Center

    Bureau of Adult, Vocational, and Technical Education (DHEW/OE), Washington, DC. Div. of Vocational and Technical Education.

    THIS LABORATORY GUIDE WAS DEVELOPED FOR AN 80-HOUR COURSE IN INDUSTRIAL RADIOGRAPHY FOR HIGH SCHOOL GRADUATES TRAINING TO BECOME BEGINNING RADIOGRAPHERS. IT IS USED IN CONJUNCTION WITH TWO OTHER VOLUMES--(1) INDUSTRIAL RADIOGRAPHY INSTRUCTOR'S GUIDE, AND (2) INUDSTRIAL RADIOGRAPHY MANUAL. THE PROGRAM WAS DEVELOPED BY A COMMITTEE OF REPRESENTATIVES…

  2. Neutron radiography of irradiated nuclear fuel at Idaho National Laboratory

    DOE PAGESBeta

    Craft, Aaron E.; Wachs, Daniel M.; Okuniewski, Maria A.; Chichester, David L.; Williams, Walter J.; Papaioannou, Glen C.; Smolinski, Andrew T.

    2015-09-10

    Neutron radiography of irradiated nuclear fuel provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Idaho National Laboratory (INL) has multiple nuclear fuels research and development programs that routinely evaluate irradiated fuels using neutron radiography. The Neutron Radiography reactor (NRAD) sits beneath a shielded hot cell facility where neutron radiography and other evaluation techniques are performed on these highly radioactive objects. The NRAD currently uses the foil-film transfer technique for imaging fuel that is time consuming but provides high spatial resolution. This study describes the NRAD and hot cell facilities,more » the current neutron radiography capabilities available at INL, planned upgrades to the neutron imaging systems, and new facilities being brought online at INL related to neutron imaging.« less

  3. Neutron radiography of irradiated nuclear fuel at Idaho National Laboratory

    SciTech Connect

    Craft, Aaron E.; Wachs, Daniel M.; Okuniewski, Maria A.; Chichester, David L.; Williams, Walter J.; Papaioannou, Glen C.; Smolinski, Andrew T.

    2015-09-10

    Neutron radiography of irradiated nuclear fuel provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Idaho National Laboratory (INL) has multiple nuclear fuels research and development programs that routinely evaluate irradiated fuels using neutron radiography. The Neutron Radiography reactor (NRAD) sits beneath a shielded hot cell facility where neutron radiography and other evaluation techniques are performed on these highly radioactive objects. The NRAD currently uses the foil-film transfer technique for imaging fuel that is time consuming but provides high spatial resolution. This study describes the NRAD and hot cell facilities, the current neutron radiography capabilities available at INL, planned upgrades to the neutron imaging systems, and new facilities being brought online at INL related to neutron imaging.

  4. Neutron Radiography of Irradiated Nuclear Fuel at Idaho National Laboratory

    NASA Astrophysics Data System (ADS)

    Craft, Aaron E.; Wachs, Daniel M.; Okuniewski, Maria A.; Chichester, David L.; Williams, Walter J.; Papaioannou, Glen C.; Smolinski, Andrew T.

    Neutron radiography of irradiated nuclear fuel provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Idaho National Laboratory (INL) has multiple nuclear fuels research and development programs that routinely evaluate irradiated fuels using neutron radiography. The Neutron Radiography reactor (NRAD) sits beneath a shielded hot cell facility where neutron radiography and other evaluation techniques are performed on these highly radioactive objects. The NRAD currently uses the foil-film transfer technique for imaging fuel that is time consuming but provides high spatial resolution. This paper describes the NRAD and hot cell facilities, the current neutron radiography capabilities available at INL, planned upgrades to the neutron imaging systems, and new facilities being brought online at INL related to neutron imaging.

  5. New developments in proton radiography at LANSCE

    NASA Astrophysics Data System (ADS)

    Morris, Christopher; Proton Radiography Team

    2014-09-01

    In a new application of nuclear physics, a facility for using proton for flash radiography has been developed at the Los Alamos Neutron Science Center (LANSCE). Protons have proven far superior to high energy x-rays for flash radiography. Although this facility is primarily used for studying very fast phenomena such as high explosive driven experiments, it is finding increasing application to other fields, such as tomography of static objects, phase changes in materials, and the dynamics of chemical reactions. The advantages of protons will be discussed and data from some of the recent experiments will be presented.

  6. Neutron beam characterization at the Neutron Radiography Reactor (NRAD)

    SciTech Connect

    Imel, G.R.; Urbatsch, T.; Pruett, D.P.; Ross, J.R.

    1990-01-01

    The Neutron Radiography Reactor (NRAD) is a 250-kW TRIGA Reactor operated by Argonne National Laboratory and is located near Idaho Falls, Idaho. The reactor and its facilities regarding radiography are detailed in another paper at this conference; this paper summarizes neutron flux measurements and calculations that have been performed to better understand and potentially improve the neutronics characteristics of the reactor.

  7. Radiography of magnetically-driven implosions of initially solid beryllium cylindrical shells for equation-of-state studies at the Z pulsed-power facility

    NASA Astrophysics Data System (ADS)

    McBride, Ryan

    2011-06-01

    The Z accelerator delivers approximately 4-MV, 26-MA electrical pulses with adjustable current rise times of 100--600 ns, as well as adjustable pulse waveforms. The magnetic pressure produced is used for various applications, including magnetically-driven implosions. The Z-Beamlet Laser (ZBL) is a pulsed (0.3-1.5 ns), multi-kJ, TW-class Nd:glass laser system that provides x-ray radiography capabilities for Z experiments. This talk focuses primarily on the radiography diagnostic used to study the magnetically-driven implosions of initially solid cylindrical shells (also referred to as ``liners''). Specifically, we discuss the 6.151-keV monochromatic backlighting system and its use in obtaining radiographs of imploding beryllium (Be) liners. The high transmission efficiency of 6.151-keV photons in Be allowed us to obtain radiographs with finite transmission throughout the radial extent of the imploding liners. Abel inverting these data, we have obtained time-resolved measurements of the imploding liner's density as a function of both axial and radial location throughout the field of view. These data are allowing us to study magneto-Rayleigh-Taylor (MRT) growth for inertial-confinement-fusion applications, as well as compression-wave propagation for equation-of-state studies (see talks by R.L. Lemke and M.R. Martin). Additionally, Z's pulse-shaping capabilities have enabled us to obtain data for both shock- and quasi-isentropically-compressed Be. Example data from MRT, shock-compression, and quasi-isentropic-compression experiments will be shown. We will also discuss planned upgrades to 25-keV radiography that will allow us to study materials with opacities beyond that of beryllium. This work was done in collaboration with R.W. Lemke, M.R. Martin, J.-P. Davis, M.D. Knudson, D.B. Sinars, S.A. Slutz, C.A. Jennings, M.E. Cuneo, D.G. Flicker, and M.C. Herrmann. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin company, for the US

  8. Proton Radiography: Its uses and Resolution Scaling

    SciTech Connect

    Mariam, Fesseha G.

    2012-08-09

    Los Alamos National Laboratory has used high energy protons as a probe in flash radiography for over a decade. In this time the proton radiography project has used 800 MeV protons, provided by the LANSCE accelerator facility at LANL, to diagnose over five-hundred dynamic experiments in support of stockpile stewardship programs as well as basic materials science. Through this effort significant experience has been gained in using charged particles as direct radiographic probes to diagnose transient systems. The results of this experience will be discussed through the presentation of data from experiments recently performed at the LANL pRad.

  9. Trauma and Mobile Radiography

    SciTech Connect

    Drafke, M.W.

    1989-01-01

    Trauma and Mobile Radiography focuses on the radiography of trauma patients and of patients confined to bed. This book offers students a foundation in the skills they need to produce quality radiograms without causing additional injury or pain to the patient. Features of this new book include: coverage of the basics of radiography and patient care, including monitoring of heavily sedated, immobile, and accident patients. Information on the injuries associated with certain types of accidents, and methods for dealing with these problems. Detailed explanation of the positioning of each anatomical area. A Quick Reference Card with information on evaluating, monitoring and radiographing trauma patients.

  10. Absolute Hugoniot measurements of polystyrene between 3 and 12 TPa using radiography of a converging shock at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Doeppner, T.; Kritcher, A. L.; Swift, D. C.; Bachmann, B.; Hawreliak, J.; Colllins, G. W.; Glenzer, S.; Rothman, S. D.; Kraus, D.; Falcone, R. W.

    2015-06-01

    A converging shock was induced with hohlraum-driven soft x-ray radiation on a solid, spherical sample of poly alpha-methyl styrene. The time-history of density profiles through the sample was measured by x-ray radiography using a laser-heated backlighter and a streak camera, viewing a diameter across the sample through slots in the hohlraum wall. Profile-matching in radius and time was used to increase the accuracy of density inferred from the transmission. The speed and compression of the shock were measured from the density profiles. The shock pressure increased with convergence, so a range of Hugoniot states was obtained from a single experiment. Using a laser power based on the early part of a ``high foot'' pulse from ignition experiments, the low end of the pressure range was brought down to 2 TPa, overlapping states accessible by experiments in plane geometry, and ensuring that the opacity of the compressed sample was the same as for unshocked material, simplifying the analysis. Shock states were measured up to 12 TPa, when the shock was close to the center of the sample. This is several times higher than has been obtained by other methods and is an absolute measurement. Performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344.

  11. Equation of state measurement at gigabar pressures using simultaneous unfolding of compression and opacity from time-resolved x-ray radiography at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Swift, Damian; Hawreliak, James; Rothman, Stephen; Bachmann, Benjamin; Kraus, Dominik; Macphee, Andrew; Doeppner, Tilo; Collins, Gilbert; Gaffney, James; Rose, Stephen; Kritcher, Andrea

    2014-10-01

    X-ray radiography of a spherically-converging shock, recorded with a streak camera, can be analyzed to determine the space- and time-variation of density and hence states on the shock Hugoniot, from the speed and compression of the shock. However, at several-fold shock compression, the opacity may vary by an order of magnitude because of ionization. We have developed an algorithm to simultaneously deduce the compression and opacity of the sample given a Lagrangian marker layer behind the shock, such as the edge of the sample. This approach relies on spatial integration to deduce the opacity in the region just behind the shock from the difference between the known and apparent mass. We assume that the change in opacity is dominated by shock-heating, so that subsequent variations, as shocked material is either released or compressed further, are negligible or can be accounted for by a model. We used this algorithm to analyze our NIF measurements of the Hugoniot of CH from 3-68 TPa and diamond from 18-65 TPa. This work was performed under the auspices of the USDoE by LLNL under Contract DE-AC52-07NA27344.

  12. Hugoniot and opacity measurements of polystyrene and carbon up to 80 TPa from radiography of converging shocks at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Kritcher, A. L.; Doeppner, T.; Swift, D. C.; Bachmann, B.; Kraus, D.; Hawreliak, J.; Gaffney, J.; Collins, G.; Glenzer, S.; Chapman, D.; Rothman, S. D.; Rose, S.; Falcone, R. W.

    2015-06-01

    Converging shocks were induced with hohlraum-driven x-ray radiation on spherical samples of poly alpha-methyl styrene and diamond. The time-history of density profiles through the sample was measured by x-ray radiography using a laser-heated backlighter and a streak camera, viewing a diameter across the sample through slots in the hohlraum wall. Profile-matching in radius and time was used to increase the accuracy of density inferred from the transmission. The shock temperature reached several hundred eV, causing ionization which significantly reduced the opacity to the 9 kV x-ray energy. The opacity change at the shock was inferred from the change in apparent mass inside a radiographic marker layer. The speed and compression of the shock were measured from the density profiles. The shock pressure increased with convergence, so a range of Hugoniot states was obtained from each experiment. Shock states were measured between 10 and 80 TPa. Presently at Washington State University.

  13. X-ray sources for radiography of warm dense matter

    NASA Astrophysics Data System (ADS)

    Benuzzi-Mounaix, Alessandra; Brambrink, Erik; Barbrel, Benjamin; Koenig, Michel; Gregory, Chris; Loupias, Bérénice; Ravasio, Alessandra; Rabec Le Gloahec, Marc; Vinci, Tommaso; Boehly, Tom; Endo, Takashi; Kimura, Tomoaki; Ozaki, Norimasa; Wei, Huigang; Aglitskiy, Yefim; Faenov, Anatoly; Pikuz, Tatiana

    2008-11-01

    The knowledge of Warm Dense Matter is important in different domains such as inertial confinement fusion, astrophysics and geophysics. The development of techniques for direct probing of this type of matter is of great interest. X-ray radiography is one of the most promising diagnostic to measure density directly. Here we present some results of low-Z material radiography and an experiment devoted to characterize a short pulse laser driven hard x-ray source for the radiography of medium and high Z matter. Experiments have been performed on LULI2000 and TW facilities at the Ecole Polytechnique.

  14. The Neutron Radiography Reactor (NRAD)

    SciTech Connect

    Imel, G.R.; McClellan, G.C.; Pruett, D.P.

    1990-01-01

    The Neutron Radiography Reactor (NRAD) operated by Argonne National Laboratory is described in this paper. NRAD was designed to allow radiography of highly absorbing reactor fuel assemblies in the vertical position on the routine basis. 7 figs.

  15. Real-time radiography

    SciTech Connect

    Bossi, R.H.; Oien, C.T.

    1981-02-26

    Real-time radiography is used for imaging both dynamic events and static objects. Fluorescent screens play an important role in converting radiation to light, which is then observed directly or intensified and detected. The radiographic parameters for real-time radiography are similar to conventional film radiography with special emphasis on statistics and magnification. Direct-viewing fluoroscopy uses the human eye as a detector of fluorescent screen light or the light from an intensifier. Remote-viewing systems replace the human observer with a television camera. The remote-viewing systems have many advantages over the direct-viewing conditions such as safety, image enhancement, and the capability to produce permanent records. This report reviews real-time imaging system parameters and components.

  16. Radiography Capabilities for Matter-Radiation Interactions in Extremes

    SciTech Connect

    Walstrom, Peter Lowell; Garnett, Robert William; Chapman, Catherine A. B; Salazar, Harry Richard; Otoole, Joseph Alfred; Barber, Ronald L.; Gomez, Tony Simon

    2015-04-28

    The Matter-Radiation Interactions in Extremes (MaRIE) experimental facility will be used to discover and design the advanced materials needed to meet 21st century national security and energy security challenges. This new facility will provide the new tools scientists need to develop next-generation materials that will perform predictably and on-demand for currently unattainable lifetimes in extreme environments. The MaRIE facility is based on upgrades to the existing LANSCE 800-MeV proton linac and a new 12-GeV electron linac and associated X-ray FEL to provide simultaneous multiple probe beams, and new experimental areas. In addition to the high-energy photon probe beam, both electron and proton radiography capabilities will be available at the MaRIE facility. Recently, detailed radiography system studies have been performed to develop conceptual layouts of high-magnification electron and proton radiography systems that can meet the experimental requirements for the expected first experiments to be performed at the facility. A description of the radiography systems, their performance requirements, and a proposed facility layout are presented.

  17. Fast Neutron Radiography at an RFQ Accelerator System

    NASA Astrophysics Data System (ADS)

    Daniels, G. C.; Franklyn, C. B.; Dangendorf, V.; Buffler, A.; Bromberger, B.

    This work introduces the Necsa Radio Frequency Quadrupole (RFQ) accelerator facility and its work concerning fast neutron radiography (FNR). Necsa operates a 4-5 MeV, up to 50 mA deuteron RFQ. The previous deuterium gas target station has been modified to enable producing a white neutron beam employing a solid B4C target. Furthermore, the high energy beam transport (HEBT) section is under adjustment to achieve a longer flight-path and a better focus. This work presents an overview of the facility, the modifications made, and introduces past and ongoing neutron radiography investigations.

  18. Point projection radiography with the FXI

    SciTech Connect

    Budil, K.; Perry, T.S.; Alvarez, S.A.

    1996-05-06

    Radiography techniques utilizing large area x-ray sources (typically {<=} 7 keV) and pinhole-imaging gated x-ray diagnostics have long been used at the Nova laser facility. However, for targets requiring higher energy x-ray backlighters (> 9 keV), low conversion efficiencies and pinhole losses combine to make this scheme unworkable. The technique of point projection radiography has been improved upon to make imaging at high x-ray energies feasible. In this scheme a {open_quotes}point{close_quotes} source of x-rays, usually a small diameter ({<=}25 {mu}m) fiber, is illuminated with a single, 100 ps pulse from the Nova laser. A gated x-ray imager with a 500 ps electronic gate width is used to record the projected image. The experimental challenges this technique presents and experimental results will be discussed.

  19. Progress in thermal neutron radiography at LENS

    NASA Astrophysics Data System (ADS)

    Jenkins, Jack; Low Energy Neutron Source (LENS) at Indiana University Collaboration

    2014-09-01

    An end station for thermal neutron radiography and tomography is in operation at the Indiana University LENS facility. Neutrons from proton-induced nuclear reactions in Beryllium are moderated and collimated into a beam which is attenuated by a scanned object on a remotely-controlled rotating table. Neutron signal is then converted to a light signal with a ZnS scintillating screen and recorded in a cooled CCD. The author has performed diagnostics on the radiography hardware and software and has tested the system's capabilities by imaging a stack of high density polyethylene cubes with diverse inlet holes and grooves on an 80/20 aluminum base. The resolution of the radiographs are seen to be less than 1mm and 3D rending software is capable of reconstructing the internal structure of the aluminum. An end station for thermal neutron radiography and tomography is in operation at the Indiana University LENS facility. Neutrons from proton-induced nuclear reactions in Beryllium are moderated and collimated into a beam which is attenuated by a scanned object on a remotely-controlled rotating table. Neutron signal is then converted to a light signal with a ZnS scintillating screen and recorded in a cooled CCD. The author has performed diagnostics on the radiography hardware and software and has tested the system's capabilities by imaging a stack of high density polyethylene cubes with diverse inlet holes and grooves on an 80/20 aluminum base. The resolution of the radiographs are seen to be less than 1mm and 3D rending software is capable of reconstructing the internal structure of the aluminum. NSF.

  20. Apparatus for proton radiography

    DOEpatents

    Martin, Ronald L.

    1976-01-01

    An apparatus for effecting diagnostic proton radiography of patients in hospitals comprises a source of negative hydrogen ions, a synchrotron for accelerating the negative hydrogen ions to a predetermined energy, a plurality of stations for stripping extraction of a radiography beam of protons, means for sweeping the extracted beam to cover a target, and means for measuring the residual range, residual energy, or percentage transmission of protons that pass through the target. The combination of information identifying the position of the beam with information about particles traversing the subject and the back absorber is performed with the aid of a computer to provide a proton radiograph of the subject. In an alternate embodiment of the invention, a back absorber comprises a plurality of scintillators which are coupled to detectors.

  1. Quantitative film radiography

    SciTech Connect

    Devine, G.; Dobie, D.; Fugina, J.; Hernandez, J.; Logan, C.; Mohr, P.; Moss, R.; Schumacher, B.; Updike, E.; Weirup, D.

    1991-02-26

    We have developed a system of quantitative radiography in order to produce quantitative images displaying homogeneity of parts. The materials that we characterize are synthetic composites and may contain important subtle density variations not discernible by examining a raw film x-radiograph. In order to quantitatively interpret film radiographs, it is necessary to digitize, interpret, and display the images. Our integrated system of quantitative radiography displays accurate, high-resolution pseudo-color images in units of density. We characterize approximately 10,000 parts per year in hundreds of different configurations and compositions with this system. This report discusses: the method; film processor monitoring and control; verifying film and processor performance; and correction of scatter effects.

  2. Cosmic Ray Scattering Radiography

    NASA Astrophysics Data System (ADS)

    Morris, C. L.

    2015-12-01

    Cosmic ray muons are ubiquitous, are highly penetrating, and can be used to measure material densities by either measuring the stopping rate or by measuring the scattering of transmitted muons. The Los Alamos team has studied scattering radiography for a number of applications. Some results will be shown of scattering imaging for a range of practical applications, and estimates will be made of the utility of scattering radiography for nondestructive assessments of large structures and for geological surveying. Results of imaging the core of the Toshiba Nuclear Critical Assembly (NCA) Reactor in Kawasaki, Japan and simulations of imaging the damaged cores of the Fukushima nuclear reactors will be presented. Below is an image made using muons of a core configuration for the NCA reactor.

  3. Digital radiography in space.

    PubMed

    Hart, Rob; Campbell, Mark R

    2002-06-01

    With the permanent habitation of the International Space Station, the planning of longer duration exploration missions, and the possibility of space tourism, it is likely that digital radiography will be needed in the future to support medical care in space. Ultrasound is currently the medical imaging modality of choice for spaceflight. Digital radiography in space is limited because of prohibitive launch costs (in the region of $20,000/kg) that severely restrict the volume, weight, and power requirements of medical care hardware. Technological increases in radiography, a predicted ten-fold decrease in future launch costs, and an increasing clinical need for definitive medical care in space will drive efforts to expand the ability to provide medical care in space including diagnostic imaging. Normal physiological responses to microgravity, in conjunction with the high-risk environment of spaceflight, increase the risk of injury and could imply an extended recovery period for common injuries. The advantages of gravity on Earth, such as the stabilization of patients undergoing radiography and the drainage of fluids, which provide radiographic contrast, are unavailable in space. This creates significant difficulties in patient immobilization and radiographic positioning. Gravity-dependent radiological signs, such as lipohemarthrosis in knee and shoulder trauma, air or fluid levels in pneumoperitoneum, pleural effusion, or bowel obstruction, and the apical pleural edge in pneumothorax become unavailable. Impaired healing processes such as delayed callus formation following fracture will have implications on imaging, and recovery time lines are unknown. The confined nature of spacecraft and the economic impossibility of launching lead-based personal protective equipment present significant challenges to crew radiation safety. A modified, free-floating radiographic C-arm device equipped with a digital detector and utilizing teleradiology support is proposed as a

  4. Particle Beam Radiography

    NASA Astrophysics Data System (ADS)

    Peach, Ken; Ekdahl, Carl

    2014-02-01

    Particle beam radiography, which uses a variety of particle probes (neutrons, protons, electrons, gammas and potentially other particles) to study the structure of materials and objects noninvasively, is reviewed, largely from an accelerator perspective, although the use of cosmic rays (mainly muons but potentially also high-energy neutrinos) is briefly reviewed. Tomography is a form of radiography which uses multiple views to reconstruct a three-dimensional density map of an object. There is a very wide range of applications of radiography and tomography, from medicine to engineering and security, and advances in instrumentation, specifically the development of electronic detectors, allow rapid analysis of the resultant radiographs. Flash radiography is a diagnostic technique for large high-explosive-driven hydrodynamic experiments that is used at many laboratories. The bremsstrahlung radiation pulse from an intense relativistic electron beam incident onto a high-Z target is the source of these radiographs. The challenge is to provide radiation sources intense enough to penetrate hundreds of g/cm2 of material, in pulses short enough to stop the motion of high-speed hydrodynamic shocks, and with source spots small enough to resolve fine details. The challenge has been met with a wide variety of accelerator technologies, including pulsed-power-driven diodes, air-core pulsed betatrons and high-current linear induction accelerators. Accelerator technology has also evolved to accommodate the experimenters' continuing quest for multiple images in time and space. Linear induction accelerators have had a major role in these advances, especially in providing multiple-time radiographs of the largest hydrodynamic experiments.

  5. Patient care in radiography

    SciTech Connect

    Ehrlich, R.A.; McCloskey, E.D.

    1989-01-01

    This book focuses on patient care procedures for radiographers. The authors focus on the role of the radiographer as a member of the health care team. The authors report on such topics as communication in patient care: safety, medico-legal considerations, transfer and positioning; physical needs; infection control; medication; CPR standards, acute situations; examination of the GI tract; contrast media; special imaging techniques and bedside radiography.

  6. Regulatory aspects of neutron radiography

    NASA Astrophysics Data System (ADS)

    Hammer, J.

    1999-11-01

    While full legislation for industrial radiography with gamma and X-rays already exists in many countries, the situation is different for neutron radiography. Therefore, the licensing for equipment and procedures in this field has to be based on basic principles of national and international rules. This contribution will explain how the regulatory body in Switzerland deals with neutron radiography installations in order to maintain national standards of health and safety.

  7. Lower Gastrointestinal (GI) Tract X-Ray (Radiography)

    MedlinePlus

    ... Resources Professions Site Index A-Z X-ray (Radiography) - Lower GI Tract Lower gastrointestinal tract radiography or ... Radiography? What is Lower GI Tract X-ray Radiography (Barium Enema)? Lower gastrointestinal (GI) tract radiography, also ...

  8. Mobile real time radiography system

    SciTech Connect

    Vigil, J.; Taggart, D.; Betts, S.

    1997-11-01

    A 450-keV Mobile Real Time Radiography (RTR) System was delivered to Los Alamos National Laboratory (LANL) in January 1996. It was purchased to inspect containers of radioactive waste produced at (LANL). Since its delivery it has been used to radiograph more than 600 drums of radioactive waste at various LANL sites. It has the capability of inspecting waste containers of various sizes from <1-gal. buckets up to standard waste boxes (SWB, dimensions 54.5 in. x 71 in. x 37 in.). It has three independent x-ray acquisition formats. The primary system used is a 12- in. image intensifier, the second is a 36-in. linear diode array (LDA) and the last is an open system. It is fully self contained with on board generator, HVAC, and a fire suppression system. It is on a 53-ft long x 8-ft. wide x 14-ft. high trailer that can be moved over any highway requiring only an easily obtainable overweight permit because it weights {approximately}38 tons. It was built to conform to industry standards for a cabinet system which does not require an exclusion zone. The fact that this unit is mobile has allowed us to operate where the waste is stored, rather than having to move the waste to a fixed facility.

  9. Scatter in Cargo Radiography

    SciTech Connect

    Erin A. Miller; Joseph A. Caggiano; Robert C. Runkle; Timothy A. White; Aaron M. Bevill

    2011-03-01

    As a complement to passive detection systems, radiographic inspection of cargo is an increasingly important tool for homeland security because it has the potential to detect highly attenuating objects associated with special nuclear material or surrounding shielding, in addition to screening for items such as drugs or contraband. Radiographic detection of such threat objects relies on high image contrast between regions of different density and atomic number (Z). Threat detection is affected by scatter of the interrogating beamin the cargo, the radiographic system itself, and the surrounding environment, which degrades image contrast. Here, we estimate the extent to which scatter plays a role in radiographic imaging of cargo containers. Stochastic transport simulations were performed to determine the details of the radiography equipment and surrounding environment, which are important in reproducing measured data and to investigate scatter magnitudes for typical cargo. We find that scatter plays a stronger role in cargo radiography than in typicalmedical imaging scenarios, even for low-density cargo, with scatter-toprimary ratios ranging from 0.14 for very low density cargo, to between 0.20 and 0.40 for typical cargo, and higher yet for dense cargo.

  10. Optimisation in general radiography

    PubMed Central

    Martin, CJ

    2007-01-01

    Radiography using film has been an established method for imaging the internal organs of the body for over 100 years. Surveys carried out during the 1980s identified a wide range in patient doses showing that there was scope for dosage reduction in many hospitals. This paper discusses factors that need to be considered in optimising the performance of radiographic equipment. The most important factor is choice of the screen/film combination, and the preparation of automatic exposure control devices to suit its characteristics. Tube potential determines the photon energies in the X-ray beam, with the selection involving a compromise between image contrast and the dose to the patient. Allied to this is the choice of anti-scatter grid, as a high grid ratio effectively removes the larger component of scatter when using higher tube potentials. However, a high grid ratio attenuates the X-ray beam more heavily. Decisions about grids and use of low attenuation components are particularly important for paediatric radiography, which uses lower energy X-ray beams. Another factor which can reduce patient dose is the use of copper filtration to remove more low-energy X-rays. Regular surveys of patient dose and comparisons with diagnostic reference levels that provide a guide representing good practice enable units for which doses are higher to be identified. Causes can then be investigated and changes implemented to address any shortfalls. Application of these methods has led to a gradual reduction in doses in many countries. PMID:21614270

  11. Image Acquisition and Quality in Digital Radiography.

    PubMed

    Alexander, Shannon

    2016-09-01

    Medical imaging has undergone dramatic changes and technological breakthroughs since the introduction of digital radiography. This article presents information on the development of digital radiography and types of digital radiography systems. Aspects of image quality and radiation exposure control are highlighted as well. In addition, the article includes related workplace changes and medicolegal considerations in the digital radiography environment. PMID:27601691

  12. Study of pipe thickness loss using a neutron radiography method

    SciTech Connect

    Mohamed, Abdul Aziz; Wahab, Aliff Amiru Bin; Yazid, Hafizal B.; Ahmad, Megat Harun Al Rashid B. Megat; Jamro, Rafhayudi B.; Azman, Azraf B.; Zin, Muhamad Rawi Md; Idris, Faridah Mohamad

    2014-02-12

    The purpose of this preliminary work is to study for thickness changes in objects using neutron radiography. In doing the project, the technique for the radiography was studied. The experiment was done at NUR-2 facility at TRIGA research reactor in Malaysian Nuclear Agency, Malaysia. Test samples of varying materials were used in this project. The samples were radiographed using direct technique. Radiographic images were recorded using Nitrocellulose film. The films obtained were digitized to processed and analyzed. Digital processing is done on the images using software Isee!. The images were processed to produce better image for analysis. The thickness changes in the image were measured to be compared with real thickness of the objects. From the data collected, percentages difference between measured and real thickness are below than 2%. This is considerably very low variation from original values. Therefore, verifying the neutron radiography technique used in this project.

  13. NEUTRON RADIOGRAPHY (NRAD) REACTOR 64-ELEMENT CORE UPGRADE

    SciTech Connect

    John D. Bess

    2014-03-01

    The neutron radiography (NRAD) reactor is a 250 kW TRIGA (registered) (Training, Research, Isotopes, General Atomics) Mark II , tank-type research reactor currently located in the basement, below the main hot cell, of the Hot Fuel Examination Facility (HFEF) at the Idaho National Laboratory (INL). It is equipped with two beam tubes with separate radiography stations for the performance of neutron radiography irradiation on small test components. The interim critical configuration developed during the core upgrade, which contains only 62 fuel elements, has been evaluated as an acceptable benchmark experiment. The final 64-fuel-element operational core configuration of the NRAD LEU TRIGA reactor has also been evaluated as an acceptable benchmark experiment. Calculated eigenvalues differ significantly (approximately +/-1%) from the benchmark eigenvalue and have demonstrated sensitivity to the thermal scattering treatment of hydrogen in the U-Er-Zr-H fuel.

  14. Study of pipe thickness loss using a neutron radiography method

    NASA Astrophysics Data System (ADS)

    Mohamed, Abdul Aziz; Wahab, Aliff Amiru Bin; Yazid, Hafizal B.; Ahmad, Megat Harun Al Rashid B. Megat; Jamro, Rafhayudi B.; Azman, Azraf B.; Zin, Muhamad Rawi Md; Idris, Faridah Mohamad

    2014-02-01

    The purpose of this preliminary work is to study for thickness changes in objects using neutron radiography. In doing the project, the technique for the radiography was studied. The experiment was done at NUR-2 facility at TRIGA research reactor in Malaysian Nuclear Agency, Malaysia. Test samples of varying materials were used in this project. The samples were radiographed using direct technique. Radiographic images were recorded using Nitrocellulose film. The films obtained were digitized to processed and analyzed. Digital processing is done on the images using software Isee!. The images were processed to produce better image for analysis. The thickness changes in the image were measured to be compared with real thickness of the objects. From the data collected, percentages difference between measured and real thickness are below than 2%. This is considerably very low variation from original values. Therefore, verifying the neutron radiography technique used in this project.

  15. Occupational exposure in Greek industrial radiography laboratories (1996-2003).

    PubMed

    Economides, S; Tritakis, P; Papadomarkaki, E; Carinou, E; Hourdakis, C; Kamenopoulou, V; Dimitriou, P

    2006-01-01

    More than 40 industrial radiography laboratories are operating in Greece using X-ray or gamma-ray sources and more than 250 workers occupationally exposed to ionising radiation in these facilities are monitored on a regular basis. This study presents the evolution of individual doses received by radiographers during the past years. The mean annual dose (MAD) of all workers as well as of exposed workers is estimated, and correlated to the types of laboratories and practices applied. The MAD of the exposed workers in industrial radiography is compared with the doses of workers in other specialties and with the doses of radiographers in other countries. Furthermore, the study attempts to propose dose constraints for the practices in industrial radiography, according to the BSS European directive and the relevant Greek radiation protection legislation. The proposed value was defined as the dose below which the annual doses of 75% of the exposed radiographers are expected to be included. PMID:16143723

  16. Deterministic simulation of thermal neutron radiography and tomography

    NASA Astrophysics Data System (ADS)

    Pal Chowdhury, Rajarshi; Liu, Xin

    2016-05-01

    In recent years, thermal neutron radiography and tomography have gained much attention as one of the nondestructive testing methods. However, the application of thermal neutron radiography and tomography is hindered by their technical complexity, radiation shielding, and time-consuming data collection processes. Monte Carlo simulations have been developed in the past to improve the neutron imaging facility's ability. In this paper, a new deterministic simulation approach has been proposed and demonstrated to simulate neutron radiographs numerically using a ray tracing algorithm. This approach has made the simulation of neutron radiographs much faster than by previously used stochastic methods (i.e., Monte Carlo methods). The major problem with neutron radiography and tomography simulation is finding a suitable scatter model. In this paper, an analytic scatter model has been proposed that is validated by a Monte Carlo simulation.

  17. Improved track-etch neutron radiography using CR-39

    NASA Astrophysics Data System (ADS)

    Pereira, M. A. Stanojev; Marques, J. G.; Pugliesi, R.; Santos, J. P.

    2014-11-01

    Currently most state-of-the-art setups for neutron radiography use scintillator screens and CCD cameras for imaging. However, in some situations it is not possible to use a CCD and alternatives must be considered. One such alternative is the well-established technique of track-etch neutron radiography, which has as main disadvantages requiring a long time for image recording and generating images with a relatively low contrast. In this work we address these negative issues and report significant improvements to recording and digitizing images using an improved setup consisting of an enriched 10B converter, a CR-39 solid state nuclear track detector and a flatbed scanner. The improved setup enables a significant reduction of the fluence required to obtain a neutron radiography image using this technique. Comparisons are made with imaging using two CCD models in the same beam line, so that the results can be extrapolated for other facilities.

  18. Beam characterization at the Neutron Radiography Reactor

    SciTech Connect

    Sarah W. Morgan; Jeffrey C. King; Chad L. Pope

    2013-12-01

    The quality of a neutron-imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam's effective length-to-diameter ratio, neutron flux profile, energy spectrum, potential image quality, and beam divergence, is vital for producing quality radiographic images. This paper provides a characterization of the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam's effective length-to-diameter ratio and potential image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. The NRAD has an effective collimation ratio greater than 125, a beam divergence of 0.3 +_ 0.1 degrees, and a gold foil cadmium ratio of 2.7. The flux profile has been quantified and the facility is an ASTM Category 1 radiographic facility. Based on bare and cadmium covered foil activation results, the neutron energy spectrum used in the current MCNP model of the radiography beamline over-samples the thermal region of the neutron energy spectrum.

  19. Digital radiography: an overview.

    PubMed

    Parks, Edwin T; Williamson, Gail F

    2002-11-15

    Since the discovery of X-rays in 1895, film has been the primary medium for capturing, displaying, and storing radiographic images. It is a technology that dental practitioners are the most familiar and comfortable with in terms of technique and interpretation. Digital radiography is the latest advancement in dental imaging and is slowly being adopted by the dental profession. Digital imaging incorporates computer technology in the capture, display, enhancement, and storage of direct radiographic images. Digital imaging offers some distinct advantages over film, but like any emerging technology, it presents new and different challenges for the practitioner to overcome. This article presents an overview of digital imaging including basic terminology and comparisons with film-based imaging. The principles of direct and indirect digital imaging modalities, intraoral and extraoral applications, image processing, and diagnostic efficacy will be discussed. In addition, the article will provide a list of questions dentists should consider prior to purchasing digital imaging systems for their practice. PMID:12444400

  20. Filters For Chest Radiography

    NASA Astrophysics Data System (ADS)

    Ramanathan, N.; Paron, J.

    1980-08-01

    The objective of low dose radiography is achieved by a judicious combination of proper kV selection, fast film-screen systems and beam filtration. A systematic study of filters was undertaken to evaluate the improvements that can be realized in terms of patient Entrance Skin Exposures (ESE) for chest radiographs. The Picker CD 135 Generator and the Automatic Chest Filmer with dynamic phototiming were used for the study. The kV dependence of ESE with various amounts of zinc and aluminum filtration is presented. The effect of filtration on image contrast is discussed. The variations of ESE with phantom thickness under different filtration conditions are also considered. It was found that the ESE can be reduced by as much as a factor of 1.8 ± .1 with no significant increase in tube loading.

  1. Multiple-image radiography

    NASA Astrophysics Data System (ADS)

    Wernick, Miles N.; Wirjadi, Oliver; Chapman, Dean; Zhong, Zhong; Galatsanos, Nikolas P.; Yang, Yongyi; Brankov, Jovan G.; Oltulu, Oral; Anastasio, Mark A.; Muehleman, Carol

    2003-12-01

    Conventional radiography produces a single image of an object by measuring the attenuation of an x-ray beam passing through it. When imaging weakly absorbing tissues, x-ray attenuation may be a suboptimal signature of disease-related information. In this paper we describe a new phase-sensitive imaging method, called multiple-image radiography (MIR), which is an improvement on a prior technique called diffraction-enhanced imaging (DEI). This paper elaborates on our initial presentation of the idea in Wernick et al (2002 Proc. Int. Symp. Biomed. Imaging pp 129-32). MIR simultaneously produces several images from a set of measurements made with a single x-ray beam. Specifically, MIR yields three images depicting separately the effects of refraction, ultra-small-angle scatter and attenuation by the object. All three images have good contrast, in part because they are virtually immune from degradation due to scatter at higher angles. MIR also yields a very comprehensive object description, consisting of the angular intensity spectrum of a transmitted x-ray beam at every image pixel, within a narrow angular range. Our experiments are based on data acquired using a synchrotron light source; however, in preparation for more practical implementations using conventional x-ray sources, we develop and evaluate algorithms designed for Poisson noise, which is characteristic of photon-limited imaging. The results suggest that MIR is capable of operating at low photon count levels, therefore the method shows promise for use with conventional x-ray sources. The results also show that, in addition to producing new types of object descriptions, MIR produces substantially more accurate images than its predecessor, DEI. MIR results are shown in the form of planar images of a phantom and a biological specimen. A preliminary demonstration of the use of MIR for computed tomography is also presented.

  2. Versatile compact X-ray radiography module for materials science under microgravity conditions

    NASA Astrophysics Data System (ADS)

    Kargl, F.; Balter, M.; Stenzel, Ch; Gruhl, Th; Daneke, N.; Meyer, A.

    2011-12-01

    A versatile compact microfocus X-ray radiography facility is presented. The facility serves as a technology demonstrator showing the applicability of X-ray radiography to experiments in space. It has been designed as an insert fully compatible with requirements of the Materials Science Laboratory aboard the International Space Station. The facility consists of a microfocus X-ray source delivering up to 20 W X-ray power at 100kV acceleration voltage and a 49.2×49.3mm RadEye2 sensor with a Scint-X scintillator at 48μm per pixel resolution with a 14bit dynamic range. The total device weight including sample chamber is 43 kg. The facility is classified as a fully protected radiography equipment according to German radiation safety laws. The capabilities of the facility for research in materials sciences are demonstrated in ground-based experiments.

  3. Upper Gastrointestinal (GI) Tract X-Ray (Radiography)

    MedlinePlus

    ... Resources Professions Site Index A-Z X-ray (Radiography) - Upper GI Tract Upper gastrointestinal tract radiography or ... X-ray? What is Upper Gastrointestinal (GI) Tract Radiography? Upper gastrointestinal tract radiography, also called an upper ...

  4. Angular signal radiography.

    PubMed

    Li, Panyun; Zhang, Kai; Bao, Yuan; Ren, Yuqi; Ju, Zaiqiang; Wang, Yan; He, Qili; Zhu, Zhongzhu; Huang, Wanxia; Yuan, Qingxi; Zhu, Peiping

    2016-03-21

    Microscopy techniques using visible photons, x-rays, neutrons, and electrons have made remarkable impact in many scientific disciplines. The microscopic data can often be expressed as the convolution of the spatial distribution of certain properties of the specimens and the inherent response function of the imaging system. The x-ray grating interferometer (XGI), which is sensitive to the deviation angle of the incoming x-rays, has attracted significant attention in the past years due to its capability in achieving x-ray phase contrast imaging with low brilliance source. However, the comprehensive and analytical theoretical framework is yet to be presented. Herein, we propose a theoretical framework termed angular signal radiography (ASR) to describe the imaging process of the XGI system in a classical, comprehensive and analytical manner. We demonstrated, by means of theoretical deduction and synchrotron based experiments, that the spatial distribution of specimens' physical properties, including absorption, refraction and scattering, can be extracted by ASR in XGI. Implementation of ASR in XGI offers advantages such as simplified phase retrieval algorithm, reduced overall radiation dose, and improved image acquisition speed. These advantages, as well as the limitations of the proposed method, are systematically investigated in this paper. PMID:27136780

  5. Fast and thermal neutron radiography

    NASA Astrophysics Data System (ADS)

    Cremer, Jay T.; Piestrup, Melvin A.; Wu, Xizeng

    2005-09-01

    There is a need for high brightness neutron sources that are portable, relatively inexpensive, and capable of neutron radiography in short imaging times. Fast and thermal neutron radiography is as an excellent method to penetrate high-density, high-Z objects, thick objects and image its interior contents, especially hydrogen-based materials. In this paper we model the expected imaging performance characteristics and limitations of fast and thermal radiography systems employing a Rose Model based transfer analysis. For fast neutron detection plastic fiber array scintllators or liquid scintillator filled capillary arrays are employed for fast neutron detection, and 6Li doped ZnS(Cu) phosphors are employed for thermal neutron detection. These simulations can provide guidance in the design, construction, and testing of neutron imaging systems. In particular we determined for a range of slab thickness, the range of thicknesses of embedded cracks (air-filled or filled with material such as water) which can be detected and imaged.

  6. Quality assurance in orthodontic radiography.

    PubMed

    Brown, J E

    1995-02-01

    The implementation of a Quality Assurance (QA) programme in orthodontic radiography is designed to improve the quality of the resultant radiographs and to reduce the number of repeat exposures. This is particularly desirable in orthodontic practice where the majority of patients are young and therefore more at risk from the detrimental effects of X-rays. A programme is described and QA tests are given that may be applied in the surgery. Particular emphasis is placed on QA measures for extraoral radiography, since this is frequently undertaken in the treatment of the orthodontic patient. PMID:7786872

  7. Neutron and gamma radiography of UO{sub 2} and TRIGA fuel elements

    SciTech Connect

    Robinson, A.H.; Gao, Y.C.; Johnson, A.G.; Ringle, J.C.

    1982-07-01

    The Oregon State TRIGA Reactor neutron radiography facility has been used to produce both neutron and gamma radiographs of reactor fuel. In this paper a comparison of the applicability of neutron and gamma radiography to both UO{sub 2} fuel pins and TRIGA fuel elements is made. In the case of UO{sub 2} fuel, conventional thermal neutron radiography produces excellent quality radiographs. These radiographs may be used to detect various defects in the fuel such as enrichment differences, cracks, end-capping, inclusions, etc. For TRIGA fuel elements, conventional thermal neutron radiography will not show the internal structure. This is due to the high hydrogen content of the fuel. These elements are typically 8.5 w/o uranium in Zr-H{sub 1.7}; the density of hydrogen in the fuel being about 80 percent that of water. Further, while epithermal radiography significantly improves the radiographs, defects may go undetected. As an alternative to neutron radiography, high energy gamma radiographs of TRIGA fuel elements have been taken using the same facility. The gamma spectrum emitted by the reactor core is sufficiently high in energy that very good radiographs may be obtained with this technique. These radiographs show excellent detail for the internal structure of the TRIGA fuel. (author)

  8. Laser driven radiography

    SciTech Connect

    Perry, M.D.; Sefcik, J.; Cowan, T.

    1997-12-20

    Intense laser (> 1021 W/cm{sup 3}) driven hard x-ray sources offer a new alternative to conventional electron accelerator Bremsstrahlung sources. These laser driven sources offer considerable simplicity in design and potential cost advantage for multiple axis views. High spatial and temporal resolution is achievable as a result of the very small source size (<100 um) and short-duration of the laser pulse. We have begun a series of experiments with the Petawatt laser at LLNL to determine the photon flux achievable with these sources and assess their potential for Stewardship applications. Additionally, we are developing a conceptual design and cost estimate of a multi-pulse, multi-axis (up to five) radiographic facility utilizing the Contained Firing Facility at site 300 and existing laser hardware.

  9. New Developments in Proton Radiography at the Los Alamos Neutron Science Center (LANSCE)

    SciTech Connect

    Morris, C. L.; Brown, E. N.; Agee, C.; Bernert, T.; Bourke, M. A. M.; Burkett, M. W.; Buttler, W. T.; Byler, D. D.; Chen, C. F.; Clarke, A. J.; Cooley, J. C.; Gibbs, P. J.; Imhoff, S. D.; Jones, R.; Kwiatkowski, K.; Mariam, F. G.; Merrill, F. E.; Murray, M. M.; Olinger, C. T.; Oro, D. M.; Nedrow, P.; Saunders, A.; Terrones, G.; Trouw, F.; Tupa, D.; Vogan, W.; Winkler, B.; Wang, Z.; Zellner, M. B.

    2015-12-30

    An application of nuclear physics, a facility for using protons for flash radiography, was developed at the Los Alamos Neutron Science Center (LANSCE). Protons have proven far superior to high energy x-rays for flash radiography because of their long mean free path, good position resolution, and low scatter background. Although this facility is primarily used for studying very fast phenomena such as high explosive driven experiments, it is finding increasing application to other fields, such as tomography of static objects, phase changes in materials and the dynamics of chemical reactions. The advantages of protons are discussed, data from some recent experiments will be reviewed and concepts for new techniques are introduced.

  10. Proximal caries detection accuracy using intraoral bitewing radiography, extraoral bitewing radiography and panoramic radiography

    PubMed Central

    Kamburoğlu, K; Kolsuz, E; Murat, S; Yüksel, S; Özen, T

    2012-01-01

    Objective To compare proximal caries detection using intraoral bitewing, extraoral bitewing and panoramic radiography. Methods 80 extracted human premolar and molar teeth with and without proximal caries were used. Intraoral radiographs were taken with Kodak Insight film (Eastman Kodak Co., Rochester, NY) using the bitewing technique. Extraoral bitewing and panoramic images were obtained using a Planmeca Promax Digital Panoramic X-ray unit (Planmeca Inc., Helsinki, Finland). Images were evaluated by three observers twice. In total, 160 proximal surfaces were assessed. Intra- and interobserver kappa coefficients were calculated. Scores obtained from the three techniques were compared with the histological gold standard using receiver operating characteristic analysis. Az values for each image type, observer and reading were compared using z-tests, with a significance level of α = 0.05. Results Kappa coefficients ranged from 0.883 to 0.963 for the intraoral bitewing, from 0.715 to 0.893 for the extraoral bitewing, and from 0.659 to 0.884 for the panoramic radiography. Interobserver agreements for the first and second readings for the intraoral bitewing images were between 0.717 and 0.780, the extraoral bitewing readings were between 0.569 and 0.707, and the panoramic images were between 0.477 and 0.740. The Az values for both readings of all three observers were highest for the intraoral bitewing. Az values for the extraoral bitewing images were higher than those of the panoramic images without statistical significance (p > 0.05). Conclusion Intraoral bitewing radiography was superior to extraoral bitewing and panoramic radiography in diagnosing proximal caries of premolar and molar teeth ex vivo. Similar intra- and interobserver coefficients were calculated for extraoral bitewing and panoramic radiography. PMID:22868296

  11. Big Explosives Experimental Facility - BEEF

    SciTech Connect

    2014-10-31

    The Big Explosives Experimental Facility or BEEF is a ten acre fenced high explosive testing facility that provides data to support stockpile stewardship and other national security programs. At BEEF conventional high explosives experiments are safely conducted providing sophisticated diagnostics such as high speed optics and x-ray radiography.

  12. Big Explosives Experimental Facility - BEEF

    ScienceCinema

    None

    2015-01-07

    The Big Explosives Experimental Facility or BEEF is a ten acre fenced high explosive testing facility that provides data to support stockpile stewardship and other national security programs. At BEEF conventional high explosives experiments are safely conducted providing sophisticated diagnostics such as high speed optics and x-ray radiography.

  13. Comparison of Digital Imaging Systems for Neutron Radiography

    NASA Astrophysics Data System (ADS)

    Pugliesi, R.; Pugliesi, Fábio; Stanojev Pereira, M. A.

    2011-09-01

    The characteristics of three digital imaging systems for neutron radiography purposes have been compared. Two of them make use of films, CR-39 and Kodak AA, and the third makes use of a LiF scintillator, for image registration. The irradiations were performed in the neutron radiography facility installed at the IEA-R1 nuclear research reactor of IPEN-CNEN/SP. According to the obtained results, the system based on CR-39 is the slowest to obtain an image, and the best in terms of resolution but the worse in terms of contrast. The system based on Kodak AA is faster than the prior, exhibits good resolution and contrast. The system based on the scintillator is the fastest to obtain an image, and best in terms of contrast but the worse in terms of resolution.

  14. Development of Compton radiography of inertial confinement fusion implosions

    SciTech Connect

    Tommasini, R.; Hatchett, S. P.; Hey, D. S.; Iglesias, C.; Izumi, N.; Koch, J. A.; Landen, O. L.; MacKinnon, A. J.; Sorce, C.; Delettrez, J. A.; Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.

    2011-05-15

    An important diagnostic tool for inertial confinement fusion will be time-resolved radiographic imaging of the dense cold fuel surrounding the hot spot. The measurement technique is based on point-projection radiography at photon energies from 60 to 200 keV where the Compton effect is the dominant contributor to the opacity of the fuel or pusher. We have successfully applied this novel Compton radiography technique to the study of the final compression of directly driven plastic capsules at the OMEGA facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The radiographs have a spatial and temporal resolution of {approx}10 {mu}m and {approx}10 ps, respectively. A statistical accuracy of {approx}0.5% in transmission per resolution element is achieved, allowing localized measurements of areal mass densities to 7% accuracy. The experimental results show 3D nonuniformities and lower than 1D expected areal densities attributed to drive asymmetries and hydroinstabilities.

  15. Development of Compton radiography of inertial confinement fusion implosionsa)

    NASA Astrophysics Data System (ADS)

    Tommasini, R.; Hatchett, S. P.; Hey, D. S.; Iglesias, C.; Izumi, N.; Koch, J. A.; Landen, O. L.; MacKinnon, A. J.; Sorce, C.; Delettrez, J. A.; Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.

    2011-05-01

    An important diagnostic tool for inertial confinement fusion will be time-resolved radiographic imaging of the dense cold fuel surrounding the hot spot. The measurement technique is based on point-projection radiography at photon energies from 60 to 200 keV where the Compton effect is the dominant contributor to the opacity of the fuel or pusher. We have successfully applied this novel Compton radiography technique to the study of the final compression of directly driven plastic capsules at the OMEGA facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The radiographs have a spatial and temporal resolution of ˜10 μm and ˜10 ps, respectively. A statistical accuracy of ˜0.5% in transmission per resolution element is achieved, allowing localized measurements of areal mass densities to 7% accuracy. The experimental results show 3D nonuniformities and lower than 1D expected areal densities attributed to drive asymmetries and hydroinstabilities.

  16. Development of Compton Radiography Diagnostics for Inertial Confinement Fusion Implosions

    SciTech Connect

    Tommasini, R; Hatchett, S P; Hey, D S; Izumi, N; Koch, J A; Landen, O L; Mackinnon, A J; Delettrez, J; Glebov, V; Stoeckl, C

    2010-11-16

    An important diagnostic tool for inertial confinement fusion will be time-resolved radiographic imaging of the dense cold fuel surrounding the hot spot. The measurement technique is based on point-projection radiography at photon energies from 60-200 keV where the Compton effect is the dominant contributor to the opacity of the fuel or pusher. We have successfully applied this novel Compton Radiography technique to the study of the final compression of directly driven plastic capsules at the OMEGA facility. The radiographs have a spatial and temporal resolution of {approx}10 {micro}m and {approx}10ps, respectively. A statistical accuracy of {approx}0.5% in transmission per resolution element is achieved, allowing localized measurements of areal mass densities to 7% accuracy. The experimental results show 3D non-uniformities and lower than 1D expected areal densities attributed to drive asymmetries and hydroinstabilities.

  17. Proton radiography and tomography with application to proton therapy

    PubMed Central

    Allinson, N M; Evans, P M

    2015-01-01

    Proton radiography and tomography have long promised benefit for proton therapy. Their first suggestion was in the early 1960s and the first published proton radiographs and CT images appeared in the late 1960s and 1970s, respectively. More than just providing anatomical images, proton transmission imaging provides the potential for the more accurate estimation of stopping-power ratio inside a patient and hence improved treatment planning and verification. With the recent explosion in growth of clinical proton therapy facilities, the time is perhaps ripe for the imaging modality to come to the fore. Yet many technical challenges remain to be solved before proton CT scanners become commonplace in the clinic. Research and development in this field is currently more active than at any time with several prototype designs emerging. This review introduces the principles of proton radiography and tomography, their historical developments, the raft of modern prototype systems and the primary design issues. PMID:26043157

  18. Proton radiography and tomography with application to proton therapy.

    PubMed

    Poludniowski, G; Allinson, N M; Evans, P M

    2015-09-01

    Proton radiography and tomography have long promised benefit for proton therapy. Their first suggestion was in the early 1960s and the first published proton radiographs and CT images appeared in the late 1960s and 1970s, respectively. More than just providing anatomical images, proton transmission imaging provides the potential for the more accurate estimation of stopping-power ratio inside a patient and hence improved treatment planning and verification. With the recent explosion in growth of clinical proton therapy facilities, the time is perhaps ripe for the imaging modality to come to the fore. Yet many technical challenges remain to be solved before proton CT scanners become commonplace in the clinic. Research and development in this field is currently more active than at any time with several prototype designs emerging. This review introduces the principles of proton radiography and tomography, their historical developments, the raft of modern prototype systems and the primary design issues. PMID:26043157

  19. Proton Radiography of a Thermal Explosion in PBX 9501

    NASA Astrophysics Data System (ADS)

    Smilowitz, Laura; Henson, Bryan; Romero, Jerry; Asay, Blaine; Sandstrom, Mary

    2007-06-01

    The understanding of thermal explosions and burn propagation lags that of detonations and shock propagation. Diagnostics such as high energy radiography have been used to image shocks, but have been previously precluded from use in thermal explosions due to their stringent timing requirements: shock propagation can be synchronized to an external diagnostic while thermal explosion can not. This issue is solved by following the evolution of the ignition volume in a thermal explosion and using a laser pulse to provide a temperature jump in that central volume during the final thermal runaway leading to ignition. Details of the laser heating which minimize the perturbation of the thermal explosion will be discussed with comparisons between auto-ignited and laser ignited tests. Thermal explosion experiments have been conducted at the Los Alamos Proton Radiography facility and have yielded images of the evolution of ignition, post-ignition burn propagation, and case failure in a radially confined cylinder of PBX 9501.

  20. Proton Radiography of a Thermal Explosion in PBX9501

    NASA Astrophysics Data System (ADS)

    Smilowitz, L.; Henson, B. F.; Romero, J. J.; Sandstrom, M. M.; Asay, B. W.; Schwartz, C.; Saunders, A.; Merrill, F.; Morris, C.; Murray, M. M.; McNeil, W. V.; Marr-Lyon, M.; Rightley, P. M.

    2007-12-01

    The understanding of thermal explosions and burn propagation lags that of detonations and shock propagation. Diagnostics such as high energy radiography have been used to image shocks, but have been previously precluded from use in thermal explosions due to their stringent timing requirements: shock propagation can be synchronized to an external diagnostic while thermal explosion can not. This issue is solved by following the evolution of the ignition volume in a thermal explosion and using a laser pulse to provide a temperature jump in that central volume during the final thermal runaway leading to ignition. Thermal explosion experiments have been conducted at the Los Alamos Proton Radiography facility and have yielded images of the evolution of ignition, post-ignition burn propagation, and case failure in a radially confined cylinder of PBX 9501. This paper presents images taken during the hours long quasistatic heating, the final minutes of thermal runaway, and the post ignition burn propagation.

  1. System for uncollimated digital radiography

    DOEpatents

    Wang, Han; Hall, James M.; McCarrick, James F.; Tang, Vincent

    2015-08-11

    The inversion algorithm based on the maximum entropy method (MEM) removes unwanted effects in high energy imaging resulting from an uncollimated source interacting with a finitely thick scintillator. The algorithm takes as input the image from the thick scintillator (TS) and the radiography setup geometry. The algorithm then outputs a restored image which appears as if taken with an infinitesimally thin scintillator (ITS). Inversion is accomplished by numerically generating a probabilistic model relating the ITS image to the TS image and then inverting this model on the TS image through MEM. This reconstruction technique can reduce the exposure time or the required source intensity without undesirable object blurring on the image by allowing the use of both thicker scintillators with higher efficiencies and closer source-to-detector distances to maximize incident radiation flux. The technique is applicable in radiographic applications including fast neutron, high-energy gamma and x-ray radiography using thick scintillators.

  2. Mobile accelerator neutron radiography system

    NASA Astrophysics Data System (ADS)

    Dance, W. E.; Carollo, S. F.; Bumgardner, H. M.

    1984-10-01

    The use of neutron radiography for the inspection and maintenance of large structures such as aircraft has been delayed by the absence of a mobile system particularly suited to the requirements of field use. This report describes the production, extensive field testing, evaluation and disposition of the first mobile neutron radiography system to satisfy the majority of requirements for field use. The system is based upon the concept of a mobile on-off neutron radiography system based on a sealed-tube ion accelerator as neutron source demonstrated earlier by the Vought Corporation. Primary features of the system are its self-propelled mobility, versatile positioning capability scaled to Army helicopter dimensions, an on-off beam capability, exposure capability measured in minutes, and suitability for AMMRC laboratory and field use. Included in the report are a description of all components of the system, an evaluation of the operation of the system, an evaluation of its radiographic capabilities, a description of installation elements for the AMMRC site, and recommendations for next-generation systems.

  3. Characterization of the Annular Core Research Reactor (ACRR) Neutron Radiography System Imaging Plane

    NASA Astrophysics Data System (ADS)

    Kaiser, Krista; Chantel Nowlen, K.; DePriest, K. Russell

    2016-02-01

    The Annular Core Research Reactor (ACRR) at Sandia National Laboratories (SNL) is an epithermal pool-type research reactor licensed up to a thermal power of 2.4 MW. The ACRR facility has a neutron radiography facility that is used for imaging a wide range of items including reactor fuel and neutron generators. The ACRR neutron radiography system has four apertures (65:1, 125:1, 250:1, and 500:1) available to experimenters. The neutron flux and spectrum as well as the gamma dose rate were characterized at the imaging plane for the ACRR's neutron radiography system for the 65:1, 125:1 and 250:1 apertures.

  4. Neutron radiography inspection of investment castings.

    PubMed

    Richards, W J; Barrett, J R; Springgate, M E; Shields, K C

    2004-10-01

    Investment casting, also known as the lost wax process, is a manufacturing method employed to produce near net shape metal articles. Traditionally, investment casting has been used to produce structural titanium castings for aero-engine applications with wall thickness less than 1 in (2.54 cm). Recently, airframe manufacturers have been exploring the use of titanium investment casting to replace components traditionally produced from forgings. Use of titanium investment castings for these applications reduces weight, cost, lead time, and part count. Recently, the investment casting process has been selected to produce fracture critical structural titanium airframe components. These airframe components have pushed the traditional inspection techniques to their physical limits due to cross sections on the order of 3 in (7.6 cm). To overcome these inspection limitations, a process incorporating neutron radiography (n-ray) has been developed. In this process, the facecoat of the investment casting mold material contains a cocalcined mixture of yttrium oxide and gadolinium oxide. The presence of the gadolinium oxide, allows for neutron radiographic imaging (and eventual removal and repair) of mold facecoat inclusions that remain within these thick cross sectional castings. Probability of detection (POD) studies have shown a 3 x improvement of detecting a 0.050 x 0.007 in2 (1.270 x 0.178 mm2) inclusion of this cocalcined material using n-ray techniques when compared to the POD using traditional X-ray techniques. Further, it has been shown that this n-ray compatible mold facecoat material produces titanium castings of equal metallurgical quality when compared to the traditional materials. Since investment castings can be very large and heavy, the neutron radiography facilities at the University of California, Davis McClellan Nuclear Radiation Center (UCD/MNRC) were used to develop the inspection techniques. The UCD/MNRC has very unique facilities that can handle large

  5. Proton Radiography: Cross Section Measurements and Detector Development

    SciTech Connect

    Michael J. Longo; H. R. Gustafson: Durga Rajaram; Turgun Nigmanov

    2010-04-16

    Proton radiography has become an important tool for predicting the performance of stockpiled nuclear weapons. Current proton radiography experiments at LANSCE are confined to relatively small targets on the order of centimeters in size because of the low beam energy. LANL scientists have made radiographs with 12 and 24 GeV protons produced by the accelerator at Brookhaven National Laboratory. These energies are in the range required for hydrotest radiography. The design of a facility for hydrotest radiography requires knowledge of the cross sections for producing high-energy particles in the forward direction, which are incorporated into the Monte Carlo simulation used in designing the beam and detectors. There are few existing measurements of neutron production cross sections for proton-nuclei interactions in the 50 GeV range, and almost no data exist for forward neutron production, especially for heavy target nuclei. Thus the data from the MIPP EMCAL and HCAL, for which our group was responsible, are critical to proton radiography. Since neutrons and photons cannot be focused by magnets, they cause a background “fog” on the images. This problem can be minimized by careful design of the focusing system and detectors. The purpose of our research was to measure forward production of neutrons produced by high-energy proton beams striking a variety of targets. The forward-going particles carry most of the energy from a high-energy proton interaction, so these are the most important to proton radiography. This work was carried out in conjunction with the Fermilab E-907 (MIPP) collaboration. Our group was responsible for designing and building the E907 forward neutron and photon calorimeters. With the support of our Stewardship Science Academic Alliances grants, we were able to design, build, and commission the calorimeters on budget and ahead of schedule. The MIPP experiment accumulated a large amount of data in the first run that ended in early 2006. Our group has

  6. A New Neutron Radiography / Tomography / Imaging Station DINGO at OPAL

    NASA Astrophysics Data System (ADS)

    Garbe, U.; Randall, T.; Hughes, C.; Davidson, G.; Pangelis, S.; Kennedy, S. J.

    A new neutron radiography / tomography / imaging instrument DINGO was built to support the area of neutron imaging research (neutron radiography/tomography) at ANSTO. The instrument is designed for an international user community and for routine quality control for defense, industrial, cultural heritage and archaeology applications. In the industrial field it provides a useful tool for studying cracking and defects in steel or other metals. The instrument construction was completed at the end of June 2013 and it is currently in the hot commissioning stage. The usable neutron flux is mainly determined by the neutron source, but it depends on the instrument position and the resolution. The instrument position for DINGO is the thermal neutron beam port HB-2 in the reactor hall. The measured flux (using gold foil) for an L/D of approximately 500 at HB-2 is 5.3*107 [n/cm2s], which is in a similar range to other facilities. A special feature of DINGO is the in-pile collimator position in front of the main shutter at HB-2. The collimator offers two pinholes with a possible L/D of 500 and 1000. A secondary collimator separates the two beams by blocking one and positions another aperture for the other beam. The whole instrument operates in two different positions, one for high resolution and one for high speed. In the current configuration DINGO measured first radiography and tomography data sets on friendly user test samples.

  7. Proton radiography experiments on shocked high explosive products.

    SciTech Connect

    Ferm, Eric N.; Dennsion, Steve; Lopez, Robert; Prestridge, Kathy; Quintana, John P.; Espinoza, Camilo; King, Gary Hogan Nick; Merrill, Frank; Kevin Morley,; Morris, Christopher L.; Pazuchanic, Peter

    2003-07-22

    We studied the propagation of detonation waves and reflections of normal incident detonation waves in explosive products using the 800 MeV proton radiography facility at LANSCE. Using this system, we obtain seven to twenty-one radiographic images of each experiment. We have examined the experimental wave velocity and density of the materials ahead and behind of the shocks as inferred from radiographs and compare them to standard explosive equations of state. Finally we compare the experiments with calculations of the experiments using the MESA hydrodynamics code.

  8. The drying process of concrete: a neutron radiography study.

    PubMed

    de Beer, F C; Strydom, W J; Griesel, E J

    2004-10-01

    The natural drying process of concrete, which has a significant effect on its characteristics, for example durability, was studied at the neutron radiography facility at SAFARI-1 nuclear research reactor, operated by Necsa. Monitoring of the movement of the water in concrete samples, which were wet cured for one day and covered on all the sides but one, was done by means of a CCD camera system. In this paper the methodology in observing the drying process will be described together with results obtained from this investigation. The measured water content and porosity results were quantified and compared reasonably well with conventional gravimetrical measurements. PMID:15246408

  9. ARG portable neutron radiography. Final report

    SciTech Connect

    Barton, J.P.

    1995-04-01

    In this report all available neutron radiographic data, including results of tests run at LANL, McClellan AFB, and University of Virginia, will be combined to outline specific transportable neutron radiography systems that could achieve the desired results as a complement to x-radiography capabilities for the Accident Response Group (ARG).

  10. INDUSTRIAL RADIOGRAPHY STUDENT GUIDE AND LABORATORY EXERCISES.

    ERIC Educational Resources Information Center

    Bureau of Adult, Vocational, and Technical Education (DHEW/OE), Washington, DC. Div. of Vocational and Technical Education.

    THIS INSTRUCTOR'S GUIDE TO AN 80-HOUR COURSE IN INDUSTRIAL RADIOGRAPHY IS COORDINATED WITH LESSONS IN THE STUDENT GUIDE AND LABORATORY EXERCISES AND IS BASED ON MATERIAL IN THE COURSE MANUAL, INDUSTRIAL RADIOGRAPHY. THE COURSE IS INTENDED TO TRAIN HIGH SCHOOL GRADUATES AS BEGINNING RADIOGRAPHERS WHO ARE EXPECTED TO BE ABLE TO EXTEND THEIR…

  11. Lesion detectability in digital radiography

    NASA Astrophysics Data System (ADS)

    Gagne, Robert M.; Boswell, Jonathan S.; Myers, Kyle J.; Peter, Guillaume

    2001-06-01

    The usefulness of Fourier-based measures of imaging performance has come into question for the evaluation of digital imaging systems. Figures of merit such as detective quantum efficiency are relevant for linear, shift-invariant systems with stationary noise. However, no digital imaging system is shift invariant, and realistic images do not satisfy the stationarity condition. Our methods for task- based evaluation of imaging systems, based on lesion detectability, do not require such assumptions. We have computed the performance of Hotelling and nonprewhitening matched-filter observers for the task of lesion detection in digital radiography.

  12. Radiography of Chaotically Moving Objects

    SciTech Connect

    Vavrik, Daniel; Jandejsek, Ivan; Dammer, Jiri; Holy, Tomas; Jakubek, Jan; Jakubek, Martin

    2007-11-26

    Radiography of moving objects is an advanced problem when the dynamic range of acquired radiograms is restricted by a limited exposition time. Exposition time has to be short to avoid image blurring due to object moving. It is possible to increase the dynamic range by summing short time radiograms set when the periodical object movement is presented as in the case of heart beating for instance. On the other hand a non periodical movement can be studied using tools of X-ray Digital Image Correlation technique. Short time radiograms are fitted into corresponding positions and consequently summed for higher data statistics as it is presented in this work.

  13. Towards Proton Therapy and Radiography at FAIR

    NASA Astrophysics Data System (ADS)

    Prall, M.; Lang, P. M.; LaTessa, C.; Mariam, F.; Merrill, F.; Shestov, L.; Simoniello, P.; Varentsov, D.; Durante, M.

    2015-04-01

    Protons having energies in the GeV range have been proposed as an alternative to Bragg-peak hadron therapy. This strategy reduces lateral scattering and overcomes uncertainties of particle range and relative biological effectiveness. GeV protons could additionally be used for targeting in image guided stereotactic radiosurgery. We experimentally demonstrated the potential of GeV protons for imaging of biological samples using E=0.8 GeV protons and the pRad setup at Los Alamos National Laboratory (LANL). In this setup, a system of magnetic lenses creates a point-to-point mapping from object to detector. This mapping compensates image blur due to lateral scattering inside the imaged (biological) object. We produced 2-dim proton radiographs of biological samples, an anthropomorphic phantom and performed simple dosimetry. High resolution tomographic reconstructions were derived from the 2-dim proton radiographs. Our experiment was performed within the framework of the PANTERA (Proton Therapy and Radiography) project. In the future, the proton microscope PRIOR (Proton Microscope for FAIR) located in the FAIR facility (Darmstadt), will focus on optimizing the technique for imaging of lesions implanted in animals and couple the irradiation with standard radiotherapy.

  14. Neutron radiography in Indian space programme

    NASA Astrophysics Data System (ADS)

    Viswanathan, K.

    1999-11-01

    Pyrotechnic devices are indispensable in any space programme to perform such critical operations as ignition, stage separation, solar panel deployment, etc. The nature of design and configuration of different types of pyrotechnic devices, and the type of materials that are put in their construction make the inspection of them with thermal neutrons more favourable than any other non destructive testing methods. Although many types of neutron sources are available for use, generally the radiographic quality/exposure duration and cost of source run in opposite directions even after four decades of research and development. But in the area of space activity, by suitably combining the X-ray and neutron radiographic requirements, the inspection of the components can be made economically viable. This is demonstrated in the Indian space programme by establishing a 15 MeV linear accelerator based neutron generator facility to inspect medium to giant solid propellant boosters by X-ray inspection and all types of critical pyro and some electronic components by neutron radiography. Since the beam contains unacceptable gamma, transfer imaging technique has been evolved and the various parameters have been optimised to get a good quality image.

  15. Capsule Ablator Inflight Performance Measurements Via Streaked Radiography Of ICF Implosions On The NIF*

    NASA Astrophysics Data System (ADS)

    Dewald, E. L.; Tommasini, R.; Mackinnon, A.; MacPhee, A.; Meezan, N.; Olson, R.; Hicks, D.; LePape, S.; Izumi, N.; Fournier, K.; Barrios, M. A.; Ross, S.; Pak, A.; Döppner, T.; Kalantar, D.; Opachich, K.; Rygg, R.; Bradley, D.; Bell, P.; Hamza, A.; Dzenitis, B.; Landen, O. L.; MacGowan, B.; LaFortune, K.; Widmayer, C.; Van Wonterghem, B.; Kilkenny, J.; Edwards, M. J.; Atherton, J.; Moses, E. I.

    2016-03-01

    Streaked 1-dimensional (slit imaging) radiography of 1.1 mm radius capsules in ignition hohlraums was recently introduced on the National Ignition Facility (NIF) and gives an inflight continuous record of capsule ablator implosion velocities, shell thickness and remaining mass in the last 3-5 ns before peak implosion time. The high quality data delivers good accuracy in implosion metrics that meets our requirements for ignition and agrees with recently introduced 2-dimensional pinhole radiography. Calculations match measured trajectory across various capsule designs and laser drives when the peak laser power is reduced by 20%. Furthermore, calculations matching measured trajectories give also good agreement in ablator shell thickness and remaining mass.

  16. Direct detector radiography versus dual reading computed radiography: feasibility of dose reduction in chest radiography.

    PubMed

    Gruber, Michael; Uffmann, Martin; Weber, Michael; Prokop, Mathias; Balassy, Csilla; Schaefer-Prokop, Cornelia

    2006-07-01

    The image quality of dual-reading computed radiography and dose-reduced direct radiography of the chest was compared in a clinical setting. The study group consisted of 50 patients that underwent three posteroanterior chest radiographs within minutes, one image obtained with a dual read-out computed radiography system (CR; Fuji 5501) at regular dose and two images with a flat panel direct detector unit (DR; Diagnost, Philips). The DR images were obtained with the same and with 50% of the dose used for the CR images. Images were evaluated in a blinded side-by-side comparison. Eight radiologists ranked the visually perceivable difference in image quality using a three-point scale. Then, three radiologists scored the visibility of anatomic landmarks in low and high attenuation areas and image noise. Statistical analysis was based on Friedman tests and Wilcoxon rank sum tests at a significance level of P<0.05. DR was judged superior to CR for the delineation of structures in high attenuation areas of the mediastinum even when obtained with 50% less dose (P<0.001). The visibility of most pulmonary structures was judged equivalent with both techniques, regardless of acquisition dose and speed level. Scores for image noise were lower for DR compared with CR, with the exception of DR obtained at a reduced dose. Thus, in this clinical preference study, DR was equivalent or even superior to the most modern dual read-out CR, even when obtained with 50% dose. A further dose reduction does not appear to be feasible for DR without significant loss of image quality. PMID:16404566

  17. Quantitative measurement of segregation phenomena in a binary-mixture fluidized bed by neutron radiography

    NASA Astrophysics Data System (ADS)

    Umekawa, Hisashi; Furui, Shuji; Oshima, Yoshihiro; Okura, Masashi; Ozawa, Mamoru; Takenaka, Nobuyuki

    2005-04-01

    Owing to a wide variety in fluidization properties of particles, segregation phenomena are hardly avoided in industrial fluidized-bed facilities. For the stability and controllability in the operation of such fluidized-beds, understanding of the relevant mechanism of particulate segregation is indispensable. Many factors, such as the difference in particle size, density, shape, and also arrangement of distributors, can be pointed out as the dominant causes for the segregation. Thus, any marking of particles for quantitative measurement may severely influence the segregation characteristic to be measured. But neutron radiography can be used for the quantitative measurement without disturbing the segregation characteristic. For estimating the segregation phenomena, evaluations of the particle fraction and the void fraction are required. For this purpose, two types of radiographies, i.e., X-ray and neutron radiographies were used in this investigation. Experimental results demonstrated the high performance of this method in investigating of segregation phenomena.

  18. The new cold neutron radiography and tomography instrument CONRAD at HMI Berlin

    NASA Astrophysics Data System (ADS)

    Hilger, A.; Kardjilov, N.; Strobl, M.; Treimer, W.; Banhart, J.

    2006-11-01

    The new cold neutron radiography instrument CONRAD is a multifunctional facility for radiography and tomography with cold neutrons at Hahn-Meitner Institut, Berlin. It is located at the end of a curved neutron guide, which faces the cold-neutron source of the BER-II research reactor. The geometry provides a cold-neutron beam with wavelengths between 2 and 12 Å. Two measuring positions are available for radiography and tomography investigations. The first one is placed at the end of the guide and it is optimized for in situ experiments in which a high neutron flux is required. The available flux at this position is approximately 10 8 cm -2 s -1. The second measuring position uses a pin-hole geometry which allows better beam collimation ( L/ D up to 1000) and higher image resolution in the range of 200 μm in the CCD based detector system (10×10 cm 2). The use of cold neutrons for radiography purposes increases the image contrast and improves the sensibility e.g., the detection of small amounts of water and hydrogen-containing materials in metal matrixes. On the other hand the cold-neutron beam can be modified easily by using diffraction and neutron optical techniques. This enables to perform radiography and tomography experiments with more sophisticated measuring techniques. Recent examples of research and industrial applications will be presented.

  19. The relationship between contrast, resolution and detectability in accelerator-based fast neutron radiography

    SciTech Connect

    Ambrosi, R. M.; Watterson, J. I. W.

    1999-06-10

    Fast neutron radiography as a method for non destructive testing is a fast growing field of research. At the Schonland Research Center for Nuclear Sciences we have been engaged in the formulation of a model for the physics of image formation in fast neutron radiography (FNR). This involves examining all the various factors that affect image formation in FNR by experimental and Monte Carlo methods. One of the major problems in the development of a model for fast neutron radiography is the determination of the factors that affect image contrast and resolution. Monte Carlo methods offer an ideal tool for the determination of the origin of many of these factors. In previous work the focus of these methods has been the determination of the scattered neutron field in both a scintillator and a fast neutron radiography facility. As an extension of this work MCNP has been used to evaluate the role neutron scattering in a specimen plays in image detectability. Image processing of fast neutron radiographs is a necessary method of enhancing the detectability of features in an image. MCNP has been used to determine the part it can play in indirectly improving image resolution and aiding in image processing. The role noise plays in fast neutron radiography and its impact on image reconstruction has been evaluated. All these factors aid in the development of a model describing the relationship between contrast, resolution and detectability.

  20. Metal thickness measurements using radiography

    NASA Astrophysics Data System (ADS)

    Achrekar, P. M.

    1986-04-01

    The present invention relates broadly to a radiographic inspection technique, and in particular to a metal thickness measurement method using radiography. The localized areas wherein the effective metal thickness is less than the minimum that is required for radiation shielding and which can render a shielding enclosure functionless, is readily determined. The invention comprises a process for assuring metal thickness in small regions. The actual metal thickness of small regions can be verified by comparing the optical densities of sections of the metal i.e., stepwedge. A comparator microphotometer, which compares optical densities of spectrum lines from spectrophotometers, compares the optical density of spectrum lines on an exposed spectrum plate (metal under test) with a standard plate (stepwedge).

  1. New developments in flash radiography

    NASA Astrophysics Data System (ADS)

    Mattsson, Arne

    2007-01-01

    The paper will review some of the latest developments in flash radiography. A series of multi anode tubes has been developed. These are tubes with several x-ray sources within the same vacuum enclosure. The x-ray sources are closely spaced, to come as close as possible to a single source. The x-ray sources are sequentially pulsed, at times that can be independently chosen. Tubes for voltages in the range 150 - 500 kV, with up to eight x-ray sources, will be described. Combining a multi anode tube with an intensified CCD camera, will make it possible to generate short "x-ray movies". A new flash x-ray control system has been developed. The system is operated from a PC or Laptop. All parameters of a multi channel flash x-ray system can be remotely set and monitored. The system will automatically store important operation parameters.

  2. Information extraction from muon radiography data

    SciTech Connect

    Borozdin, K. N.; Asaki, T. J.; Chartrand, R.; Hengartner, N. W.; Hogan, G. E.; Morris, C. L.; Priedhorsky, W. C.; Schirato, R.C.; Schultz, L. J.; Sottile, M. J.; Vixie, K. R.; Wohlberg, B. E.; Blanpied, G.

    2004-01-01

    Scattering muon radiography was proposed recently as a technique of detection and 3-d imaging for dense high-Z objects. High-energy cosmic ray muons are deflected in matter in the process of multiple Coulomb scattering. By measuring the deflection angles we are able to reconstruct the configuration of high-Z material in the object. We discuss the methods for information extraction from muon radiography data. Tomographic methods widely used in medical images have been applied to a specific muon radiography information source. Alternative simple technique based on the counting of high-scattered muons in the voxels seems to be efficient in many simulated scenes. SVM-based classifiers and clustering algorithms may allow detection of compact high-Z object without full image reconstruction. The efficiency of muon radiography can be increased using additional informational sources, such as momentum estimation, stopping power measurement, and detection of muonic atom emission.

  3. Corrosion Inhibitors as Penetrant Dyes for Radiography

    NASA Technical Reports Server (NTRS)

    Novak, Howard L.; Hall, Phillip B.

    2003-01-01

    Liquid/vapor-phase corrosion inhibitors (LVCIs) have been found to be additionally useful as penetrant dyes for neutron radiography (and perhaps also x-radiography). Enhancement of radiographic contrasts by use of LVCIs can reveal cracks, corrosion, and other defects that may be undetectable by ultrasonic inspection, that are hidden from direct optical inspection, and/or that are difficult or impossible to detect in radiographs made without dyes.

  4. Nationwide surveys of chest, abdomen, lumbosacral spine radiography, and upper gastrointestinal fluoroscopy: a summary of findings.

    PubMed

    Spelic, David C; Kaczmarek, Richard V; Hilohi, Mike C; Moyal, Albert E

    2010-03-01

    This paper reports findings from Nationwide Evaluation of X-ray Trends surveys conducted in 2001, 2002, and 2003 of clinical facilities that perform routine radiographic examinations of the adult chest, abdomen, lumbosacral spine, and upper gastrointestinal fluoroscopic examinations. Randomly identified clinical facilities were surveyed in approximately 40 participating states. For the surveyed radiographic exams, additional facilities that use computed radiography or digital radiography were surveyed to ensure adequate sample sizes for determining comparative statistics. State radiation control personnel performed site visits and collected data on patient exposure, radiographic/fluoroscopic technique factors, image quality, and quality-control and quality-assurance practices. Results of the NEXT surveys are compared with those of previous surveys conducted in 1964 and 1970 by the U.S. Public Health Service and the Food and Drug Administration. An estimated 155 million routine adult chest exams were performed in 2001. Average patient entrance skin air kerma from chest radiography at facilities using digital-based imaging modalities was found to be significantly higher (p < 0.001), but not so for routine abdomen or lumbosacral spine radiography. Digital-based imaging showed a substantial reduction in patient exposure for the radiographic portion of the routine upper gastrointestinal fluoroscopy exam. Long-term trends in surveyed diagnostic examinations show that average patient exposures are at their lowest levels. Of concern is the observation that a substantial fraction of surveyed non-hospital sites indicated they do not regularly have a medical physics survey conducted on their radiographic equipment. These facilities are likely unaware of the radiation doses they administer to their patients. PMID:20147791

  5. Modified Bootstrap Sensitometry In Radiography

    NASA Astrophysics Data System (ADS)

    Bednarek, Daniel R.; Rudin, Stephen

    1981-04-01

    A new modified bootstrap approach to sensitometry is presented which provides H and D curves that show almost exact agreement with those obtained using conventional methods. Two bootstrap techniques are described; both involve a combination of inverse-square and stepped-wedge modulation of the radiation field and provide intensity-scale sensitometric curves as appropriate for medical radiography. H and D curves obtained with these modified techniques are compared with those obtained for screen-film combinations using inverse-square sensitometry as well as with those obtained for direct x-ray film using time-scale sensitometry. The stepped wedge of the Wisconsin X-Ray Test Cassette was used in the bootstrap approach since it provides sufficient exposure latitude to encompass the useful density range of medical x-ray film. This approach makes radiographic sensitometry quick and convenient, allowing accurate characteristic curves to be obtained for any screen-film cassette using standard diagnostic x-ray equipment.

  6. Thorium-uranium fission radiography

    NASA Technical Reports Server (NTRS)

    Haines, E. L.; Weiss, J. R.; Burnett, D. S.; Woolum, D. S.

    1976-01-01

    Results are described for studies designed to develop routine methods for in-situ measurement of the abundance of Th and U on a microscale in heterogeneous samples, especially rocks, using the secondary high-energy neutron flux developed when the 650 MeV proton beam of an accelerator is stopped in a 42 x 42 cm diam Cu cylinder. Irradiations were performed at three different locations in a rabbit tube in the beam stop area, and thick metal foils of Bi, Th, and natural U as well as polished silicate glasses of known U and Th contents were used as targets and were placed in contact with mica which served as a fission track detector. In many cases both bare and Cd-covered detectors were exposed. The exposed mica samples were etched in 48% HF and the fission tracks counted by conventional transmitted light microscopy. Relative fission cross sections are examined, along with absolute Th track production rates, interaction tracks, and a comparison of measured and calculated fission rates. The practicality of fast neutron radiography revealed by experiments to data is discussed primarily for Th/U measurements, and mixtures of other fissionable nuclei are briefly considered.

  7. Time of flight fast neutron radiography

    NASA Astrophysics Data System (ADS)

    Loveman, R.; Bendahan, J.; Gozani, T.; Stevenson, J.

    1995-05-01

    Neutron radiography with fast or thermal neutrons is a standard technique for non-destructive testing (NDT). Here we report results for fast neutron radiography both as an adjunct to pulsed fast neutron analysis (PFNA) and as a stand-alone method for NDT. PFNA is a new technique for utilizing a collimated pulsed neutron beam to interrogate items and determine their elemental composition. By determining the time of flight for gamma-rays produced by (n,n' gamma X) reactions, a three dimensional image can be produced. Neutron radiography data taken with the same beam provides an important constraint for image reconstruction, and in particular is important in inferring the amount of hydrogen within the interrogated item. As a stand-alone device, the radiography measurement can be used to image items as large as cargo containers as long as their density is not too high. The use of a pulsed beam gives the further advantage of a time of flight measurement on the transmitted neutrons. By gating the radiography signal on the time of flight appropriate to the energy of the primary neutrons, most build-up from scattered neutrons can be eliminated. The pulsed beam also greatly improves the signal to background and extends the range of the neutron radiography. Simulation results will be presented which display the advantage of this constraint in particular for statistically limited data. Experimental results will be presented which show some of the limitations likely in a PFNA system utilizing neutron radiography data. Experimental and simulation results will demonstrate possible uses for this type of radiographic data in identifying contraband substances such as drugs.

  8. Development of backlighting sources for a Compton Radiography diagnostic of Inertial Confinement Fusion targets

    SciTech Connect

    Tommasini, R

    2010-04-23

    An important diagnostic tool for inertial confinement fusion is time-resolved imaging of the dense cold fuel surrounding the hot spot. Here we report on the source and diagnostic development of hard x-ray radiography and on the first radiographs of direct drive implosions obtained at photon energies up to about 100keV, where the Compton effect is the dominant contributor to the shell opacity. The radiographs of direct drive, plastic shell implosions obtained at the OMEGA laser facility have a spatial resolution of {approx}10um and a temporal resolution of {approx}10ps. This novel Compton Radiography is an invaluable diagnostic tool for Inertial Confinement Fusion targets, and will be integrated at the National Ignition Facility (NIF).

  9. New Developments in Proton Radiography at the Los Alamos Neutron Science Center (LANSCE)

    DOE PAGESBeta

    Morris, C. L.; Brown, E. N.; Agee, C.; Bernert, T.; Bourke, M. A. M.; Burkett, M. W.; Buttler, W. T.; Byler, D. D.; Chen, C. F.; Clarke, A. J.; et al

    2015-12-30

    An application of nuclear physics, a facility for using protons for flash radiography, was developed at the Los Alamos Neutron Science Center (LANSCE). Protons have proven far superior to high energy x-rays for flash radiography because of their long mean free path, good position resolution, and low scatter background. Although this facility is primarily used for studying very fast phenomena such as high explosive driven experiments, it is finding increasing application to other fields, such as tomography of static objects, phase changes in materials and the dynamics of chemical reactions. The advantages of protons are discussed, data from some recentmore » experiments will be reviewed and concepts for new techniques are introduced.« less

  10. Muon radiography for exploration of Mars geology

    NASA Astrophysics Data System (ADS)

    Kedar, S.; Tanaka, H. K. M.; Naudet, C. J.; Jones, C. E.; Plaut, J. P.; Webb, F. H.

    2013-06-01

    Muon radiography is a technique that uses naturally occurring showers of muons (penetrating particles generated by cosmic rays) to image the interior of large-scale geological structures in much the same way as standard X-ray radiography is used to image the interior of smaller objects. Recent developments and application of the technique to terrestrial volcanoes have demonstrated that a low-power, passive muon detector can peer deep into geological structures up to several kilometers in size, and provide crisp density profile images of their interior at ten meter scale resolution. Preliminary estimates of muon production on Mars indicate that the near horizontal Martian muon flux, which could be used for muon radiography, is as strong or stronger than that on Earth, making the technique suitable for exploration of numerous high priority geological targets on Mars. The high spatial resolution of muon radiography also makes the technique particularly suited for the discovery and delineation of Martian caverns, the most likely planetary environment for biological activity. As a passive imaging technique, muon radiography uses the perpetually present background cosmic ray radiation as the energy source for probing the interior of structures from the surface of the planet. The passive nature of the measurements provides an opportunity for a low power and low data rate instrument for planetary exploration that could operate as a scientifically valuable primary or secondary instrument in a variety of settings, with minimal impact on the mission's other instruments and operation.

  11. Weakly ionized cerium plasma radiography

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Hayasi, Yasuomi; Germer, Rudolf; Koorikawa, Yoshitake; Murakami, Kazunori; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ichimaru, Toshio; Obata, Fumiko; Takahashi, Kiyomi; Sato, Sigehiro; Takayama, Kazuyoshi; Ido, Hideaki

    2004-02-01

    In the plasma flash x-ray generator, high-voltage main condenser of about 200 nF is charged up to 55 kV by a power supply, and electric charges in the condenser are discharged to an x-ray tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is of a demountable triode that is connected to a turbo molecular pump with a pressure of approximately 1 mPa. As electron flows from the cathode electrode are roughly converged to a rod cerium target of 3.0 mm in diameter by electric field in the x-ray tube, the weakly ionized linear plasma, which consists of cerium ions and electrons, forms by target evaporating. At a charging voltage of 55 kV, the maximum tube voltage was almost equal to the charging voltage of the main condenser, and the peak current was about 20 kA. When the charging voltage was increased, weakly ionized cerium plasma formed, and the K-series characteristic x-ray intensities increased. The x-ray pulse widths were about 500 ns, and the time-integrated x-ray intensity had a value of about 40 μC/kg at 1.0 m from x-ray source with a charging voltage of 55 kV. In the angiography, we employed a film-less computed radiography (CR) system and iodine-based microspheres. Because K-series characteristic x-rays are absorbed easily by the microspheres, high-contrast angiography has been performed.

  12. Thyroid dose distribution in dental radiography

    SciTech Connect

    Bristow, R.G.; Wood, R.E.; Clark, G.M. )

    1989-10-01

    The anatomic position and proven radiosensitivity of the thyroid gland make it an organ of concern in dental radiography. A calibrated thermoluminescent dosimetry system was used to investigate the absorbed dose (microGy) to the thyroid gland resultant from a minimum irradiated volume, intraoral full-mouth radiography technique with the use of rectangular collimation with a lead-backed image receptor, and conventional panoramic radiography performed with front and rear lead aprons. Use of the minimum irradiated volume technique resulted in a significantly decreased absorbed dose over the entire thyroid region ranging from 100% to 350% (p less than 0.05). Because this intraoral technique results in radiographs with greater image quality and also exposes the thyroid gland to less radiation than the panoramic, this technique may be an alternative to the panoramic procedure.

  13. Problems associated with veterinary dental radiography.

    PubMed

    Eisner, E R

    1990-03-01

    Veterinarians have been radiographing animal skulls for many years, but sophisticated dentistry was not widely used until the 1970s. Elevated awareness of veterinary dental techniques has led to the need for producing accurate radiographic images of the teeth and periodontal structures. Many problems arise for the clinician who treats small animals who has, before this time, radiographed the skull of dogs and cats solely for the purpose of assessing neoplastic, infectious, or traumatic disease of the mandible, maxilla, or calvarium and now desires to perform dental radiography. This chapter will describe the advantages and disadvantages of some of the more common types of radiographic equipment and supplies, discuss extraoral and intraoral radiographic positioning and technique, identify anatomic landmarks and diagnostic features of intraoral radiography, and offer suggestions concerning the art of using dental radiography in veterinary practice. PMID:2134590

  14. Digital radiography. A comparison with modern conventional imaging

    PubMed Central

    Bansal, G J

    2006-01-01

    The development of computed radiography over the past two decades has transformed radiological imaging. The radiology departments in the 21st century will look very different from those in the preceding period. In this review, the development of digital radiography is presented with a description of its various forms and a comparison with screen film radiography. PMID:16822918

  15. Use of Linear Induction Accelerators for Flash Radiography

    NASA Astrophysics Data System (ADS)

    Caporaso, George

    1998-04-01

    Induction accelerators have been used for over a decade as flash x-ray sources for radiography. A new machine is presently under construction at Los Alamos National Laboratory and a second machine is under design for installation adjacent to the first one to form the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility. This second accelerator will provide a 2 microsecond pulse which will be subdivided by a fast kicker system to provide a sequence of four or more 70 ns pulses along a single line of sight. An advanced system to provide multiple pulses over a longer time interval and over many lines of sight will be discussed along with the technological advances in solid-state pulsed power, fast kickers and target systems necessary to make the concept a reality. *This work was performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under Contract No.W-7405-Eng-48.

  16. [Conventional dental radiography and future prospectives].

    PubMed

    Youssefzadeh, S; Gahleitner, A; Bernhart, D; Bernhart, T

    1999-12-01

    Until recently, conventional dental radiology was performed by dentists and orofacial surgeons. Due to the rapid development of radiological technique, the demand of radiological advice is increasing. The radiologists see more and more dental patients in their daily routine. The aim of this article is to give an overview on established dental radiology and a glimpse into the future. Conventional dental radiology and digital radiography are presently in use. Intraoral technique comprises dental films, bite-wing views and occlusal radiographs. Panoramic views and cephalometric radiographs are done with extraoral technique. Digital radiography lacks all processes in behalf of film development. It leads to dose reduction and enables image manipulation. PMID:10643025

  17. Lithium batteries: Application of neutron radiography

    NASA Astrophysics Data System (ADS)

    Kamata, Masahiro; Esaka, Takao; Fujine, Shigenori; Yoneda, Kenji; Kanda, Keiji

    Several kinds of primary and secondary commercial lithium batteries, such as CR1/3 · 1H (Fujitsu), CR1220 and BR435 (Panasonic), ML1220 (Sanyo Excel) were investigated using neutron radiography; the variation of the lithium distribution inside these batteries upon discharging (and charging) were clarified by analyzing their visualized images. It was demonstrated that neutron radiography is a potential and useful method, especially in evaluating the reversibility of rechargeable batteries, which have been used under different discharging/charging conditions.

  18. Predicting image blur in proton radiography: comparisons between measurements and Monte Carlo simulations

    SciTech Connect

    von Wittenau, A; Aufderheide, M B; Henderson, G L

    2010-05-07

    Given the cost and lead-times involved in high-energy proton radiography, it is prudent to model proposed radiographic experiments to see if the images predicted would return useful information. We recently modified our raytracing transmission radiography modeling code HADES to perform simplified Monte Carlo simulations of the transport of protons in a proton radiography beamline. Beamline objects include the initial diffuser, vacuum magnetic fields, windows, angle-selecting collimators, and objects described as distorted 2D (planar or cylindrical) meshes or as distorted 3D hexahedral meshes. We present an overview of the algorithms used for the modeling and code timings for simulations through typical 2D and 3D meshes. We next calculate expected changes in image blur as scattering materials are placed upstream and downstream of a resolution test object (a 3 mm thick sheet of tantalum, into which 0.4 mm wide slits have been cut), and as the current supplied to the focusing magnets is varied. We compare and contrast the resulting simulations with the results of measurements obtained at the 800 MeV Los Alamos LANSCE Line-C proton radiography facility.

  19. Survey of patient exposure from general radiography and mammography in Japan in 2014.

    PubMed

    Asada, Y; Suzuki, S; Minami, K; Shirakawa, S; Kobayashi, M

    2016-06-01

    With the objective of reducing patient exposure to radiation, we conducted a questionnaire survey regarding radiographic conditions in 2014. Here we report estimates of dose exposure in general radiography and mammography through an investigation and comparison of present patient exposure conditions. Questionnaires were sent to 3000 facilities nationwide in Japan. Surveys asked questions on a total of 16 items related to general radiography, including the chest, abdomen, and breast. Output data from x-ray tubes measured in the Chubu area of Japan were used as the mean in these estimates. The index of patient exposure was adopted as the entrance skin dose (ESD) for general radiography and as the mean glandular dose (MGD) for mammography. The response rate for this survey was 21.9%. Our results showed that doses received through the use of flat-panel detector (FPD) devices were lower than those received through computed radiography devices, except for the ankle joint (e.g. in chest examination, the dose from FPD and CR was 0.24 mGy, 0.31 mGy on the average, respectively). These results suggest that more widespread use of FPD devices could lead to decreases in the ESD and MGD, thereby reducing patient exposure. PMID:26975874

  20. INDUSTRIAL RADIOGRAPHY COURSE, INSTRUCTORS' GUIDE. VOLUME 2.

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station. Engineering Extension Service.

    INFORMATION RELATIVE TO THE LESSON PLANS IN "INDUSTRIAL RADIOGRAPHY COURSE, INSTRUCTOR'S GUIDE, VOLUME I" (VT 003 565) IS PRESENTED ON 52 INFORMATION SHEETS INCLUDING THE SUBJECTS SHIELDING EQUATIONS AND LOGARITHMS, METAL PROPERTIES, FIELD TRIP INSTRUCTIONS FOR STUDENTS, WELDING SYMBOLS AND SIZES, SAMPLE REPORT FORMS, AND TYPICAL SHIPPING…

  1. Infection control practices for dental radiography.

    PubMed

    Palenik, Charles John

    2004-06-01

    Infection control for dental radiography employs the same materials, processes, and techniques used in the operatory, yet unless proper procedures are established and followed, there is a definite potential for cross-contamination to clinical area surfaces and DHCP. In general, the aseptic practices used are relatively simple and inexpensive, yet they require complete application in every situation. PMID:15218669

  2. Safety Testing of Industrial Radiography Devices

    SciTech Connect

    Trapp, D.J.

    1999-09-29

    The Nuclear Regulatory Commission contracted the Savannah River Technology Center to verify the relevancy of the 10 CFR Part 34 requirements for the normal use of portable gamma radiography systems and to propose recommendations for changes or modifications to the requirements.

  3. Fresh-Core Reload of the Neutron Radiography (NRAD) Reactor with Uranium(20)-Erbium-Zirconium-Hydride Fuel

    SciTech Connect

    John D. Bess; Thomas L. Maddock; Margaret A. Marshall; Leland M. Montierth

    2014-03-01

    The neutron radiography (NRAD) reactor is a 250 kW TRIGA® (Training, Research, Isotopes, General Atomics) Mark II , tank-type research reactor currently located in the basement, below the main hot cell, of the Hot Fuel Examination Facility (HFEF) at the Idaho National Laboratory (INL). It is equipped with two beam tubes with separate radiography stations for the performance of neutron radiography irradiation on small test components. The 60-fuel-element operational core configuration of the NRAD LEU TRIGA reactor has been evaluated as an acceptable benchmark experiment. The initial critical configuration developed during the fuel loading process, which contains only 56 fuel elements, has not been evaluated as it is very similar to the evaluated core configuration. The benchmark eigenvalue is 1.0012 ± 0.0029. Calculated eigenvalues differ significantly (~±1%) from the benchmark eigenvalue and have demonstrated sensitivity to the thermal scattering treatment of hydrogen in the U-Er-Zr-H fuel.

  4. Fresh-Core Reload of the Neutron Radiography (NRAD) Reactor with Uranium(20)-Erbium-Zirconium-Hydride Fuel

    SciTech Connect

    John D. Bess; Thomas L. Maddock; Margaret A. Marshall; Leland M. Montierth

    2013-03-01

    The neutron radiography (NRAD) reactor is a 250 kW TRIGA® (Training, Research, Isotopes, General Atomics) Mark II , tank-type research reactor currently located in the basement, below the main hot cell, of the Hot Fuel Examination Facility (HFEF) at the Idaho National Laboratory (INL). It is equipped with two beam tubes with separate radiography stations for the performance of neutron radiography irradiation on small test components. The initial critical configuration developed during the fuel loading process, which contains only 56 fuel elements, has been evaluated as an acceptable benchmark experiment. The 60-fuel-element operational core configuration of the NRAD LEU TRIGA reactor has also been evaluated as an acceptable benchmark experiment. Calculated eigenvalues differ significantly (~±1%) from the benchmark eigenvalue and have demonstrated sensitivity to the thermal scattering treatment of hydrogen in the U-Er-Zr-H fuel.

  5. Fresh-Core Reload of the Neutron Radiography (NRAD) Reactor with Uranium(20)-Erbium-Zirconium-Hydride Fuel

    SciTech Connect

    John D. Bess; Thomas L. Maddock; Margaret A. Marshall; Leland M. Montierth

    2011-03-01

    The neutron radiography (NRAD) reactor is a 250 kW TRIGA® (Training, Research, Isotopes, General Atomics) Mark II , tank-type research reactor currently located in the basement, below the main hot cell, of the Hot Fuel Examination Facility (HFEF) at the Idaho National Laboratory (INL). It is equipped with two beam tubes with separate radiography stations for the performance of neutron radiography irradiation on small test components. The 60-fuel-element operational core configuration of the NRAD LEU TRIGA reactor has been evaluated as an acceptable benchmark experiment. The initial critical configuration developed during the fuel loading process, which contains only 56 fuel elements, has not been evaluated as it is very similar to the evaluated core configuration. The benchmark eigenvalue is 1.0012 ± 0.0029. Calculated eigenvalues differ significantly (~±1%) from the benchmark eigenvalue and have demonstrated sensitivity to the thermal scattering treatment of hydrogen in the U-Er-Zr-H fuel.

  6. Recent Developments in Electronic Radiography

    SciTech Connect

    Fry, D.A.; Claytor, T.N.; Davis, A.W.; Jones, M.H.; Sheats, M.J.; Stupin, D.M.; Summa, D.A.; White, S.M.; Hefele, J.; Watson, S.A.; Kauppila, T.J.; Mueller, K.H.

    1999-07-18

    An overview of the radiographic capabilities with emphasis on electronic image detection and processing at the Los Alamos National Laboratory is presented. Fixed facilities and portable x-ray sources and imaging systems make up the Los Alamos capability. Examples of imaging with large area amorphous silicon imaging panels, a portable computed tomography system, high speed x-ray imaging applications and equipment, and small area, high resolution imagers are given. Radiographic simulation and reverse engineering from radiographic images to computer aided design files and solid models is also presented.

  7. Compton Radiography of ICF implosions

    NASA Astrophysics Data System (ADS)

    Tommasini, Riccardo

    2011-10-01

    Laser-produced, micro-wire backlighters in a point-projection geometry, generating X-ray photons with energies ranging from 50keV to 200 keV, have been used to record time-resolved 2D radiographs of the dense cold fuel surrounding the hot spot of inertial confinement fusion implosions at the OMEGA facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The radiographs have spatial and temporal resolution of ~10 μm and ~10 ps, respectively, and allow localized measurements of areal mass densities with 7% accuracy. The experimental results show 3D non-uniformities and lower than 1D expected areal densities attributed to drive asymmetries and hydroinstabilities. The areal density measurements from radiographs compare well to the values obtained from charged particle spectrometry. We are preparing similar experiments using this technique to obtain radiographs of cryogenic implosions at the National Ignition Facility. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  8. Pediatric radiography entrance doses for some routine procedures in three hospitals within eastern Nigeria

    PubMed Central

    Egbe, N. O.; Inyang, S. O.; Ibeagwa, O. B.; Chiaghanam, N. O.

    2008-01-01

    A survey of the entrance surface doses in the routine radiography of children in eastern Nigeria has been carried out in three hospitals, using thermoluminescence detectors. Chest, abdomen, lumbar spine, skull and pelvis were covered in this study. Findings reveal that doses are higher than the recommended reference values elsewhere, as well as values reported for Sudan. The mean percentage difference in entrance doses for chest radiography for this study and an earlier one carried out for three hospitals in the west of Nigeria is about 44.7%. The high doses are traceable to a lack of standardization in procedure, resulting in use of low tube voltages and high currents for examination, as well as the status of facilities in the area. Recommendations are made for immediate corrective measures to lower the doses. PMID:20041050

  9. Digital radiography: a focus on clinical utility

    SciTech Connect

    Price, R.R.; Rollo, F.D.; Monahan, W.G.; James, A.E. Jr.

    1982-01-01

    This book is interesting and timely in that it covers the new and exciting area of digital radiography. The book begins with chapters on the physics, instrumentation, and terminology of digital radiography. Then cost-benefit ratios, legal implication, and outpatient vs. inpatient studies are discussed. The clinical chapters follow. These are applicable to the head and neck, heart, lungs, kidneys, peripheral arteries, and pediatric population. Discussion then centers on intraarterial digital subtraction, clinical experience at Wisconsin, nonangiography application of digital radiology in children, and analog film-screen subtraction intravenous angiography. The book ends by briefly discussing microwave imaging, nuclear magnetic resonance, emission tomography, real-time and Doppler sonography, analog tomography, and the future photoelectric radiology department.

  10. Characterizing flash-radiography source spots.

    PubMed

    Ekdahl, Carl

    2011-12-01

    Flash radiography of large hydrodynamic experiments driven by high explosives is a venerable diagnostic technique in use at many laboratories. The size of the radiographic source spot is often quoted as an indication of the resolving power of a particular flash-radiography machine. A variety of techniques for measuring spot size have evolved at the different laboratories, as well as different definitions of spot size. Some definitions are highly dependent on the source spot intensity distributions, and not necessarily well correlated with resolution. The concept of limiting resolution based on bar target measurements is introduced, and shown to be equivalent to the spatial wavenumber at a modulation transfer function value of 5%. This resolution is shown to be better correlated with the full width at half-maximum of the spot intensity distribution than it is with other definitions of spot size. PMID:22193263

  11. Deflection evaluation using time-resolved radiography

    SciTech Connect

    Fry, D.A.; Lucero, J.P.

    1990-01-01

    Time-resolved radiography is the creation of an x-ray image for which both the start-exposure and stop-exposure times are known with respect to the event under study. The combination of image and timing are used to derive information about the event. We have applied time-resolved radiography to evaluate motions of explosive-driven events. In the particular application discussed here, our intent is to measure maximum deflections of the components involved. Exposures are made during the time just before to just after the event of interest occurs. A smear or blur of motion out to its furthest extent is recorded on the image. Comparison of the dynamic images with static images allows deflection measurements to be made. 2 figs.

  12. A system for fast neutron radiography

    SciTech Connect

    Klann, R.T.

    1996-05-01

    A system has been designed and a neutron generator installed to perform fast neutron radiography. With this sytem, objects as small as a coin or as large as a waste drum can be radiographed. The neutron source is an MF Physics A-711 neutron generator which produces 3x10{sup 10} neutrons/second with an average energy of 14.5 MeV. The radiography system uses x-ray scintillation screens and film in commercially available cassettes. The cassettes have been modified to include a thin sheet of plastic to convert neutrons to protons through elastic scattering from hydrogen and other low Z materials in the plastic. For film densities from 1.8 to 3.0, exposures range from 1.9x10{sup 7} to 3.8x10{sup 8} n/cm{sup 2} depending on the type of screen and film.

  13. Wizardry and radiography: a clinical case.

    PubMed

    Desrentes, M

    1990-10-01

    The author encountered a patient who had undergone various sorcery and wizardry practices. At radiography performed because of lower back pain, 100 sharp metal foreign bodies (such as needles and sharpened paper clips) were found scattered between his neck and pelvis. The patient evidently swallowed some of the objects to gain protection against aggression from humans or spiritual beings. However, the means of introduction of some of the objects (eg, the needles in the neck) cannot be determined. PMID:2399308

  14. Digital radiography: Present detectors and future developments

    SciTech Connect

    Perez-Mendez, V.

    1990-08-01

    Present detectors for digital radiography are of two classes: real time detectors and storage (non real time) types. Present real time detectors consist of image intensifier tubes with an internal cesium iodide layer x-ray converter. Non real time detectors involve linear sweep arrays or storage detectors such as film. Future detectors discussed here can be of both types utilizing new technologies such as hydrogenated amorphous silicon photodiode arrays coupled to thin film transistor arrays. 17 refs., 10 figs.

  15. Proton Radiography Peers into Metal Solidification

    PubMed Central

    Clarke, Amy; Imhoff, Seth; Gibbs, Paul; Cooley, Jason; Morris, Christopher; Merrill, Frank; Hollander, Brian; Mariam, Fesseha; Ott, Thomas; Barker, Martha; Tucker, Tim; Lee, Wah-Keat; Fezzaa, Kamel; Deriy, Alex; Patterson, Brian; Clarke, Kester; Montalvo, Joel; Field, Robert; Thoma, Dan; Smith, James; Teter, David

    2013-01-01

    Historically, metals are cut up and polished to see the structure and to infer how processing influences the evolution. We can now peer into a metal during processing without destroying it using proton radiography. Understanding the link between processing and structure is important because structure profoundly affects the properties of engineering materials. Synchrotron x-ray radiography has enabled real-time glimpses into metal solidification. However, x-ray energies favor the examination of small volumes and low density metals. Here we use high energy proton radiography for the first time to image a large metal volume (>10,000 mm3) during melting and solidification. We also show complementary x-ray results from a small volume (<1 mm3), bridging four orders of magnitude. Real-time imaging will enable efficient process development and the control of structure evolution to make materials with intended properties; it will also permit the development of experimentally informed, predictive structure and process models. PMID:23779063

  16. Novel embossed radiography system utilizing energy subtraction

    NASA Astrophysics Data System (ADS)

    Osawa, Akihiro; Sato, Eiichi; Matsukiyo, Hiroshi; Enomoto, Toshiyuki; Watanabe, Manabu; Nagao, Jiro; Abderyim, Purkhet; Tanaka, Etsuro; Izumisawa, Mitsuru; Ogawa, Akira; Sato, Shigehiro

    2008-08-01

    Digital subtraction is useful for carrying out embossed radiography by shifting an x-ray source, and energy subtraction is an important technique for imaging target region by deleting unnecessary region in vivo. X-ray generator had a 100-μm-focus tube, energy subtraction was performed at tube voltages of 40 and 60 kV, and a 3.0-mm-thick aluminum filter was used to absorb low-photon-energy bremsstrahlung x-rays. Embossed radiography was achieved with cohesion imaging using a flat panel detector (FPD) with pixel sizes of 48×48 μm, and the shifting distance of the x-ray source in horizontal direction and the distance between the x-ray source and the FPD face were 5.0 mm and 1.0 m, respectively. At a tube voltage of 60 kV and a tube current of 0.50 mA, x-ray intensities without filtering and with filtering were 307 and 28.4 μGy/s, respectively, at 1.0 m from the source. In embossed radiography of non-living animals, the spatial resolution measured using a lead test chart was approximately 70 μm, and we observed embossed images of fine bones, soft tissues, and coronary arteries of approximately 100 μm.

  17. Proton Radiography Peers into Metal Solidification

    SciTech Connect

    Clarke, Amy J.; Imhoff, Seth D.; Gibbs, Paul J.; Cooley, Jason C.; Morris, Christopher; Merrill, Frank E.; Hollander, Brian J.; Mariam, Fesseha G.; Ott, Thomas J.; Barker, Martha R.; Tucker, Tim J.; Lee, Wah-Keat; Fezzaa, Kamel; Deriy, Alex; Patterson, Brian M.; Clarke, Kester D.; Montalvo, Joel D.; Field, Robert D.; Thoma, Dan J.; Smith, James L.; Teter, David F.

    2013-06-19

    Historically, metals are cut up and polished to see the structure and to infer how processing influences the evolution. We can now peer into a metal during processing without destroying it using proton radiography. Understanding the link between processing and structure is important because structure profoundly affects the properties of engineering materials. Synchrotron x-ray radiography has enabled real-time glimpses into metal solidification. However, x-ray energies favor the examination of small volumes and low density metals. In this study, we use high energy proton radiography for the first time to image a large metal volume (>10,000 mm3) during melting and solidification. We also show complementary x-ray results from a small volume (<1mm3), bridging four orders of magnitude. In conclusion, real-time imaging will enable efficient process development and the control of the structure evolution to make materials with intended properties; it will also permit the development of experimentally informed, predictive structure and process models.

  18. Proton Radiography Peers into Metal Solidification

    DOE PAGESBeta

    Clarke, Amy J.; Imhoff, Seth D.; Gibbs, Paul J.; Cooley, Jason C.; Morris, Christopher; Merrill, Frank E.; Hollander, Brian J.; Mariam, Fesseha G.; Ott, Thomas J.; Barker, Martha R.; et al

    2013-06-19

    Historically, metals are cut up and polished to see the structure and to infer how processing influences the evolution. We can now peer into a metal during processing without destroying it using proton radiography. Understanding the link between processing and structure is important because structure profoundly affects the properties of engineering materials. Synchrotron x-ray radiography has enabled real-time glimpses into metal solidification. However, x-ray energies favor the examination of small volumes and low density metals. In this study, we use high energy proton radiography for the first time to image a large metal volume (>10,000 mm3) during melting and solidification.more » We also show complementary x-ray results from a small volume (<1mm3), bridging four orders of magnitude. In conclusion, real-time imaging will enable efficient process development and the control of the structure evolution to make materials with intended properties; it will also permit the development of experimentally informed, predictive structure and process models.« less

  19. Alteration of computer dental radiography images.

    PubMed

    Bruder, G A; Casale, J; Goren, A; Friedman, S

    1999-04-01

    This study was designed to determine if digital images stored on the hard drive of a Schick computer dental radiography system could be exported, altered, and then restored to the drive without any visible signs of alteration. Digital images were downloaded from the computer dental radiography system using an I-Omega Zip Drive, 100-MB capacity, and then opened in Corel Photo Paint where images were altered and manufacturer export symbols were edited. The resulting images were printed to a default printer (Fargo Foto Fun). The ease of manipulation of the exported digital images reflects the need for the manufacturer to implement safeguards so that the integrity of digital imaging cannot be compromised. Computer dental radiography has many advantages: conservation of time (instant radiographs), less radiation (50 to 60%), no chemical waste, and many viewing options. However, questions that might be raised regarding the ability of persons with minimal computer expertise, using a commercially available program to alter images should be addressed. PMID:10425956

  20. Emergency skull radiography: the effect of restrictive criteria on skull radiography and CT use

    SciTech Connect

    Baker, S.R.; Gaylord, G.M.; Lantos, G.; Tabaddor, K.; Gallagher, E.J.

    1985-08-01

    A prospective study was performed to determine the effect of restrictive criteria on the use of emergency skull radiography and computed tomography (CT) of the head. Emergency skull radiography required the completion of a special requisition form. Emergency CT of the head was done at the request of senior consultants and was available on a full-time basis. Over 1 year, 2758 skull studies were performed, a decrease of 39.1% when compared with the year before restrictive criteria were instituted, during which 4587 skull examinations were done. In the same period, the number of emergency CT scans of the head increased by 45.7%, from 471 in the control year to 686 in the experimental year. With the use of restrictive criteria, a net savings of $164,000 was achieved. Our results suggest that the use of restrictive criteria is a cost-effective means of limiting skull radiography when CT of the head is readily available.

  1. Radiography and fluoroscopy, 1920 to the present.

    PubMed

    Krohmer, J S

    1989-11-01

    A survey of radiological procedures carried out in 1980 by J. L. Johnson and D. L. Abernathy indicated that of the 181 million procedures performed in that year, there were 77.5% plain radiographic studies, 12.7% contrast studies, 4.0% sonographic studies, 3.2% nuclear medicine studies, 1.8% CT studies and 0.8% special vascular procedures and cardiac catheterizations. Note that over 90% of all the studies were of the "conventional" type and that fewer than 2% were CT studies. In the early 70's when CT was introduced, it was predicted that it would soon take over most of radiography; some 7 or 8 years later, it was obvious that this would not take place. According to Tanako of the Fuji Photo Film Co. Ltd., conventional radiography has resisted being pushed aside because of its very high information content: 4-6 megabytes per image. A CT image contains about 0.5 megabytes. If a system is to take over from conventional radiography, it will have to overcome this large difference in information content. Digital or computed radiography seems capable of this, but probably not for some time (perhaps, 10 or 20 years). It seems unlikely that there will be much change, except for refinement, in the image intensified fluoroscopy equipment used for observing dynamic processes, and it will probably not be replaced. Another situation which will preclude the rapid demise of conventional radiography is financial inertia: There is between 5 and 10 billion dollars worth of diagnostic equipment in hospitals in this country and significant amount more in private offices and clinics. It is true that the amount has diminished in recent years, but this has been more because of DRG's than because of "takeover" by new modes of imaging. It is not likely that this investment will be given up quickly or easily. One must also keep in mind that the film digitization and the photostimulable phosphor digital systems, described above, do use existing radiographic equipment, and the image

  2. Wavelength tunable device for neutron radiography and tomography

    SciTech Connect

    Treimer, W.; Strobl, M.; Kardjilov, N.; Hilger, A.; Manke, I.

    2006-11-13

    A special double monochromator system was tested for a conventional operating tomography setup in order to use a broad wavelength band of monochromatic neutrons for radiography and tomography. Scanning through the wavelength region of Bragg edges, it is possible to make series of radiographs and tomographs at different wavelengths from 2.0 until 6.5 A. So no beam hardening influences the measurements and is not to be corrected. With this instrument for cold neutron radiography and tomography, energy selecting quantitative radiography, stress and strain mapping, and phase radiography were performed.

  3. Source characterization and modeling development for monoenergetic-proton radiography experiments on OMEGA

    SciTech Connect

    Manuel, M. J.-E.; Zylstra, A. B.; Rinderknecht, H. G.; Casey, D. T.; Rosenberg, M. J.; Sinenian, N.; Li, C. K.; Frenje, J. A.; Seguin, F. H.; Petrasso, R. D.

    2012-06-15

    A monoenergetic proton source has been characterized and a modeling tool developed for proton radiography experiments at the OMEGA [T. R. Boehly et al., Opt. Comm. 133, 495 (1997)] laser facility. Multiple diagnostics were fielded to measure global isotropy levels in proton fluence and images of the proton source itself provided information on local uniformity relevant to proton radiography experiments. Global fluence uniformity was assessed by multiple yield diagnostics and deviations were calculated to be {approx}16% and {approx}26% of the mean for DD and D{sup 3}He fusion protons, respectively. From individual fluence images, it was found that the angular frequencies of Greater-Than-Or-Equivalent-To 50 rad{sup -1} contributed less than a few percent to local nonuniformity levels. A model was constructed using the Geant4 [S. Agostinelli et al., Nuc. Inst. Meth. A 506, 250 (2003)] framework to simulate proton radiography experiments. The simulation implements realistic source parameters and various target geometries. The model was benchmarked with the radiographs of cold-matter targets to within experimental accuracy. To validate the use of this code, the cold-matter approximation for the scattering of fusion protons in plasma is discussed using a typical laser-foil experiment as an example case. It is shown that an analytic cold-matter approximation is accurate to within Less-Than-Or-Equivalent-To 10% of the analytic plasma model in the example scenario.

  4. Source characterization and modeling development for monoenergetic-proton radiography experiments on OMEGA

    NASA Astrophysics Data System (ADS)

    Manuel, M. J.-E.; Zylstra, A. B.; Rinderknecht, H. G.; Casey, D. T.; Rosenberg, M. J.; Sinenian, N.; Li, C. K.; Frenje, J. A.; Séguin, F. H.; Petrasso, R. D.

    2012-06-01

    A monoenergetic proton source has been characterized and a modeling tool developed for proton radiography experiments at the OMEGA [T. R. Boehly et al., Opt. Comm. 133, 495 (1997)], 10.1016/S0030-4018(96)00325-2 laser facility. Multiple diagnostics were fielded to measure global isotropy levels in proton fluence and images of the proton source itself provided information on local uniformity relevant to proton radiography experiments. Global fluence uniformity was assessed by multiple yield diagnostics and deviations were calculated to be ˜16% and ˜26% of the mean for DD and D3He fusion protons, respectively. From individual fluence images, it was found that the angular frequencies of ≳50 rad-1 contributed less than a few percent to local nonuniformity levels. A model was constructed using the Geant4 [S. Agostinelli et al., Nuc. Inst. Meth. A 506, 250 (2003)], 10.1016/S0168-9002(03)01368-8 framework to simulate proton radiography experiments. The simulation implements realistic source parameters and various target geometries. The model was benchmarked with the radiographs of cold-matter targets to within experimental accuracy. To validate the use of this code, the cold-matter approximation for the scattering of fusion protons in plasma is discussed using a typical laser-foil experiment as an example case. It is shown that an analytic cold-matter approximation is accurate to within ≲10% of the analytic plasma model in the example scenario.

  5. Neutron radiography with sub-15 μm resolution through event centroiding

    NASA Astrophysics Data System (ADS)

    Tremsin, Anton S.; McPhate, Jason B.; Vallerga, John V.; Siegmund, Oswald H. W.; Bruce Feller, W.; Lehmann, Eberhard; Kaestner, Anders; Boillat, Pierre; Panzner, Tobias; Filges, Uwe

    2012-10-01

    Conversion of thermal and cold neutrons into a strong ˜1 ns electron pulse with an absolute neutron detection efficiency as high as 50-70% makes detectors with 10B-doped Microchannel Plates (MCPs) very attractive for neutron radiography and microtomography applications. The subsequent signal amplification preserves the location of the event within the MCP pore (typically 6-10 μm in diameter), providing the possibility to perform neutron counting with high spatial resolution. Different event centroiding techniques of the charge landing on a patterned anode enable accurate reconstruction of the neutron position, provided the charge footprints do not overlap within the time required for event processing. The new fast 2×2 Timepix readout with >1.2 kHz frame rates provides the unique possibility to detect neutrons with sub-15 μm resolution at several MHz/cm2 counting rates. The results of high resolution neutron radiography experiments presented in this paper, demonstrate the sub-15 μm resolution capability of our detection system. The high degree of collimation and cold spectrum of ICON and BOA beamlines combined with the high spatial resolution and detection efficiency of MCP-Timepix detectors are crucial for high contrast neutron radiography and microtomography with high spatial resolution. The next generation of Timepix electronics with sparsified readout should enable counting rates in excess of 107 n/cm2/s taking full advantage of high beam intensity of present brightest neutron imaging facilities.

  6. AXIS: an instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF.

    PubMed

    Hall, G N; Izumi, N; Tommasini, R; Carpenter, A C; Palmer, N E; Zacharias, R; Felker, B; Holder, J P; Allen, F V; Bell, P M; Bradley, D; Montesanti, R; Landen, O L

    2014-11-01

    Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV-200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition. PMID:25430200

  7. [The place of radiography in endodontic treatment carried out in general practice in Dakar].

    PubMed

    Gaye, F; Mbaye, M; Faye, B; Diallo, B

    2002-03-01

    An investigation conducted over dental surgeons of 52 dental offices in Dakar and it's near suburb (40 from private sector and 12 from public and quasi-public) has shown that the use of retro-alveolar radiography during endodontic treatment was not systematic, due to the price of retro-alveolar film, waste of time and relative facility of the endodontic treatment of monoradicular teeth. The preparatory negative is favored (32.70%) particularly by private dental surgeons, who use two retro-alveolar films for endodontic treatment: pre and post operative radiography (30%). The immediate post operator control is executed only in case of post-operator pains by public and quasi-public dental surgeons (16.67%) with one retro-alveolar film on average for the endodontic treatment; at term any radiographic control is done. Three retro-alveolar films per endodontic treatment were exceptionally used (9.61%) and offset incidences (15%) are not much used as well as support-films (angulators). The retro-alveolar radiography is still a reliable guide for a clinical success in endodontic treatment with a minimum of three retro-alveolar films and offset incidences. PMID:12061249

  8. AXIS: An instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF

    SciTech Connect

    Hall, G. N. Izumi, N.; Tommasini, R.; Carpenter, A. C.; Palmer, N. E.; Zacharias, R.; Felker, B.; Holder, J. P.; Allen, F. V.; Bell, P. M.; Bradley, D.; Montesanti, R.; Landen, O. L.

    2014-11-15

    Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV–200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

  9. Threshold perception performance with computed and screen-film radiography: implications for chest radiography.

    PubMed

    Dobbins, J T; Rice, J J; Beam, C A; Ravin, C E

    1992-04-01

    Images of a phantom obtained with computed radiography and standard screen-film imaging were compared to evaluate observer threshold perception performance with a modified contrast-detail technique. Optimum exposure necessary for performance with the imaging plate technique to match that with screen-film techniques was determined, as was comparative performance with variation in kilovoltages, plate type, spatial enhancement, and hard-copy interpolation method. It was found that computed radiography necessitates about 75%-100% more exposure than screen-film radiography to optimally match performance with Ortho-C film with Lanex regular or medium screens (Eastman Kodak, Rochester, NY) for detection of objects 0.05-2.0 cm in diameter. However, only minimal loss of detection performance (approximately 10% overall) was experienced if standard screen-film exposures were used with computed radiography. Little change in observer performance was found with variation in plate type, spatial enhancement, or method of hard-copy interpolation. However, perception performance with computed radiographic images was better at lower kilovoltages. PMID:1549669

  10. Computed radiography in an emergency department setting

    NASA Astrophysics Data System (ADS)

    Andriole, Katherine P.; Gould, Robert G.; Arenson, Ronald L.

    1997-05-01

    Evaluation of radiologist and non-radiologist physician acceptance of computed radiography (CR) as an alternative to film-based radiography in an emergency department (ED) is performed. All emergency department radiographs are performed using photostimulable phosphor plates and rad by a computed radiography laser reader placed in the former emergency department darkroom. Soft copy images are simultaneously transmitted to high- and medium-resolution dual-monitor display stations located in radiology and ED reading rooms respectively. The on-call radiologist is automatically paged by the Radiology Information System (RIS) upon exam completion, to read the new ED imaging study. Patient demographic information including relevant clinical history is conveyed to the radiologist via the RIS. A 'wet read' preliminary radiology report is immediately transmitted back to the ED. Radiology and ED physicians are surveyed to ascertain preferences for CR or traditional screen-film, based on system implementation, image viewing and clinical impact issues. Preliminary results indicate a preference for filmless CR among the ED physicians if digital reliability and speed issues are met. This preference appears to be independent of physician level of experience. Inexperienced radiologists-in-training appear to have less comfort with softcopy reading for primary diagnosis. However, additional training in softcopy reading techniques can improve confidences. Image quality issues are most important tot he radiologist, while speed and reliability are the major issues for ED physicians. Reasons for CR preference include immediate access to images on display stations, near-zero exam retake rates, and improved response time and communication between radiology and the emergency department clinician.

  11. 10 CFR 34.13 - Specific license for industrial radiography.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Specific license for industrial radiography. 34.13 Section 34.13 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Specific Licensing Provisions § 34.13 Specific license...

  12. 10 CFR 34.13 - Specific license for industrial radiography.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Specific license for industrial radiography. 34.13 Section 34.13 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Specific Licensing Provisions § 34.13 Specific license...

  13. 10 CFR 34.13 - Specific license for industrial radiography.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Specific license for industrial radiography. 34.13 Section 34.13 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Specific Licensing Provisions § 34.13 Specific license...

  14. 10 CFR 34.13 - Specific license for industrial radiography.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Specific license for industrial radiography. 34.13 Section 34.13 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Specific Licensing Provisions § 34.13 Specific license...

  15. 10 CFR 34.13 - Specific license for industrial radiography.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Specific license for industrial radiography. 34.13 Section 34.13 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Specific Licensing Provisions § 34.13 Specific license...

  16. [Digital radiography in tomography of the facial bones].

    PubMed

    Ibing, H P; Vogel, H; Biebesheimer, V

    1988-09-01

    In 14 patients the x-ray findings of dental, mandibular and maxillary roentgen diagnosis were compared with conventional tomography and tomography by digital radiography. All details important for diagnosis were shown by both techniques. Tomography by digital radiography offered a more convenient approach and pictures easier to be interpreted than pictures by conventional tomography. PMID:3175474

  17. Diagnostics of coated fuel particles by neutron and synchrotron radiography

    SciTech Connect

    Momot, G. V.; Podurets, K. M.; Pogorelyi, D. K.; Somenkov, V. A.; Yakovenko, E. V.

    2011-12-15

    The nondestructive monitoring of coated fuel particles has been performed using contact neutron radiography and refraction radiography based on synchrotron radiation. It is shown that these methods supplement each other and have a high potential for determining the sizes, densities, and isotopic composition of the particle components.

  18. Computed radiography imaging plates and associated methods of manufacture

    DOEpatents

    Henry, Nathaniel F.; Moses, Alex K.

    2015-08-18

    Computed radiography imaging plates incorporating an intensifying material that is coupled to or intermixed with the phosphor layer, allowing electrons and/or low energy x-rays to impart their energy on the phosphor layer, while decreasing internal scattering and increasing resolution. The radiation needed to perform radiography can also be reduced as a result.

  19. Learning Styles of Radiography Students during Clinical Practice

    ERIC Educational Resources Information Center

    Ward, L. Patrice

    2009-01-01

    The purpose of this study was to identify and describe the common learning styles of radiography students during clinical practice. Quantitative, descriptive research methodology identified the learning styles of radiography students. A single self-report questionnaire, developed to assess learning styles in clinical practice, was administered…

  20. Axial Tomography from Digitized Real Time Radiography

    DOE R&D Accomplishments Database

    Zolnay, A. S.; McDonald, W. M.; Doupont, P. A.; McKinney, R. L.; Lee, M. M.

    1985-01-18

    Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

  1. Digital Radiography Qualification of Tube Welding

    NASA Technical Reports Server (NTRS)

    Carl, Chad

    2012-01-01

    The Orion Project will be directing Lockheed Martin to perform orbital arc welding on commodities metallic tubing as part of the Multi Purpose Crew Vehicle assembly and integration process in the Operations and Checkout High bay at Kennedy Space Center. The current method of nondestructive evaluation is utilizing traditional film based x-rays. Due to the high number of welds that are necessary to join the commodities tubing (approx 470), a more efficient and expeditious method of nondestructive evaluation is desired. Digital radiography will be qualified as part of a broader NNWG project scope.

  2. Technique for chest radiography for pneumoconiosis

    SciTech Connect

    Sargent, E.N.

    1982-01-01

    Routine radiographic chest examinations have been performed using a variety of techniques. Although chest radiography is one of the most commonly performed radiographic examinations, it is often difficult to obtain consistently good quality roentgenograms. This publication provides a simple guide and relatively easy solution to the many problems that radiologic technologists might encounter. The language is purposely relatively simple and care has been taken to avoid difficult mathematical and physical explanations. The intent is to provide an easily referrable text for those who may encounter difficulties in producing acceptable chest radiographs.

  3. Some problems encountered in endodontic radiography.

    PubMed

    Lim, K C; Teo, C S

    1986-07-01

    This retrospective survey highlights some of the problems faced by undergraduate students using the bisecting angle technique in endodontic radiography. The radiographs of maxillary incisors and premolars were observed to suffer from a greater amount of distortion than radiographs of the corresponding mandibular teeth. Further, the presence of rubber dam equipment affected the accuracy of the radiographs, and this was more apparent on the radiographs of the maxillary incisors and premolars compared to the mandibular incisors and premolars. Other problems identified included superimposition, indistinct and missed root apices. Methods to overcome these problems are suggested. PMID:3777839

  4. Simulation of computed radiography with imaging plate detectors

    SciTech Connect

    Tisseur, D.; Costin, M.; Mathy, F.; Schumm, A.

    2014-02-18

    Computed radiography (CR) using phosphor imaging plate detectors is taking an increasing place in Radiography Testing. CR uses similar equipment as conventional radiography except that the classical X-ray film is replaced by a numerical detector, called image plate (IP), which is made of a photostimulable layer and which is read by a scanning device through photostimulated luminescence. Such digital radiography has already demonstrated important benefits in terms of exposure time, decrease of source energies and thus reduction of radioprotection area besides being a solution without effluents. This paper presents a model for the simulation of radiography with image plate detectors in CIVA together with examples of validation of the model. The study consists in a cross comparison between experimental and simulation results obtained on a step wedge with a classical X-ray tube. Results are proposed in particular with wire Image quality Indicator (IQI) and duplex IQI.

  5. Proton radiography, nuclear cross sections and multiple scattering

    NASA Astrophysics Data System (ADS)

    Sjue, Sky; Lansce Proton Radiography Team

    2015-10-01

    Proton radiography is a valuable tool for assessing dynamic experiments over times as short as 100 nanoseconds. Facilities now exist or are in development in the China, Germany, Russia and the United States with proton energies ranging from 800 MeV to 50 GeV. The multiple Coulomb scattering distribution of protons and the cross sections for proton interactions with the nucleus both depend on the proton energy. A detailed understanding of these effects is necessary to gain the best possible quantitative information from proton generated radiographs. We will present an analysis of the integrated nuclear cross sections for various metals at 800 MeV kinetic energy using step wedges at Los Alamos Neutron Science Center at 800 MeV, along with results at 24 GeV from Alternating Gradient Synchrotron at 24 GeV. The results will be compared with models of multiple scattering and several models of the nuclear interactions. Finally, we will discuss trends in the interplay between nuclear attenuation and multiple scattering as a function of proton energy.

  6. Conical Rotating Aperture Geometries In Digital Radiography

    NASA Astrophysics Data System (ADS)

    Rudin, Stephen; Bednarek, Daniel R.; Wong, Roland

    1981-11-01

    Applications of conical rotating aperture (RA) geometries to digital radiography are described. Two kinds of conical RA imaging systems are the conical scanning beam and the conical scanning grid assemblies. These assemblies comprise coaxial conical surface(s) the axis of which is collinear with the x-ray focal spot. This geometry allows accurate alignment and continuous focusing of the slits or the grid lines. Image receptors which use solid state photodiode arrays are described for each type of conical RA system: multiple linear arrays for the conical scanning beam assembly and multiple area arrays for the conical scanning grid assembly. The digital rotating-aperture systems combine the wide dynamic range characteristics of solid state detectors with the superior scatter-rejection advantages of scanned beam approaches. The high scanning-beam velocities attainable by the use of rotating apertures should make it possible to obtain digital images for those procedures such as chest radiography which require large fields of view and short exposure times.

  7. Patient dose management in digital radiography

    PubMed Central

    Vano, E; Fernandez Soto, JM

    2007-01-01

    Purpose: To present the experience in patient dose management and the development of an online audit tool for digital radiography. Materials and methods: Several tools have been developed to extract the information contained in the DICOM header of digital images, collect radiographic parameters, calculate patient entrance doses and other related parameters, and audit image quality. Results: The tool has been used for mammography, and includes images from over 25,000 patients, over 75,000 chest images, 100,000 computed radiography procedures and more than 1,000 interventional radiology procedures. Examples of calculation of skin dose distribution in interventional cardiology based upon information of DICOM header and the results of dosimetric parameters for cardiology procedures in 2006 are presented. Conclusion: Digital radiology has great advantages for imaging and patient dose management. Dose reports, QCONLINE systems and the MPPS DICOM service are good tools to optimise procedures and to manage patient dosimetry data. The implementation of the ongoing IEC-DICOM standard for patient dose structured reports will improve dose management in digital radiology. PMID:21614273

  8. Optimization and quality control of computed radiography

    NASA Astrophysics Data System (ADS)

    Willis, Charles E.; Weiser, John C.; Leckie, Robert G.; Romlein, John R.; Norton, Gary S.

    1994-05-01

    Computed radiography (CR) is a relatively new technique for projection radiography. Few hospitals have CR devices in routine service and only a handful have more than one CR unit. As such, the clinical knowledge base does not yet exist to establish quality control (QC) procedures for CR devices. Without assurance that CR systems are operating within nominal limits, efforts to optimize CR performance are limited in value. A complete CR system includes detector plates that vary in response, cassettes, an electro-optical system for developing the image, computer algorithms for processing the raw image, and a hard copy output device. All of these subsystems are subject to variations in performance that can degrade image quality. Using CR manufacturer documentation, we have defined acceptance protocols for two different Fuji CR devices, the FCR 7000 and the AC1+, and have applied these tests to ten individual machines. We have begun to establish baseline performance measures and to determine measurement frequencies. CR QC is only one component of the overall quality control for totally digital radiology departments.

  9. Neutron Radiography Reactor Reactivity -- Focused Lessons Learned

    SciTech Connect

    Eric Woolstenhulme; Randal Damiana; Kenneth Schreck; Ann Marie Phillips; Dana Hewit

    2010-11-01

    As part of the Global Threat Reduction Initiative, the Neutron Radiography Reactor (NRAD) at the Idaho National Laboratory (INL) was converted from using highly enriched uranium (HEU) to low enriched uranium (LEU) fuel. After the conversion, NRAD resumed operations and is meeting operational requirements. Radiography image quality and the number of images that can be produced in a given time frame match pre-conversion capabilities. However, following the conversion, NRAD’s excess reactivity with the LEU fuel was less than it had been with the HEU fuel. Although some differences between model predictions and actual performance are to be expected, the lack of flexibility in NRAD’s safety documentation prevented adjusting the reactivity by adding more fuel, until the safety documentation could be modified. To aid future reactor conversions, a reactivity-focused Lessons Learned meeting was held. This report summarizes the findings of the lessons learned meeting and addresses specific questions posed by DOE regarding NRAD’s conversion and reactivity.

  10. A system for fast neutron radiography

    SciTech Connect

    Klann, R.T.

    1997-04-01

    A system has been designed and a neutron generator installed to perform fast neutron radiography. With this system, objects as small as a coin and as large as a 19 liter container have been radiographed. The neutron source is an MF Physics A-711 neutron generator which produces 3 x 10[sup 10] neutrons/second with an average energy of 14. 5 MeV. The radiography system uses x-ray scintillation screens and film in commercially available light-tight cassettes. The cassettes have been modified to include a thin sheet of plastic to produce protons from the neutron beam through elastic scattering from hydrogen and other low Z materials in the plastic. For film densities from 1.8 to 3.0, exposures range from 1.9 x 10[sup 7] n/cm[sup 2] to 3.8 x 10[sup 8] n/cm[sup 2] depending on the type of screen and film. The optimum source-to-film distance was found to be 150 cm. At this distance, the geometric unsharpness was determined to be approximately 2.2-2.3 mm and the smallest hole that could be resolved in a 1.25 cm thick sample had a diameter of 0.079 cm.

  11. Imaging properties of digital magnification radiography

    SciTech Connect

    Boyce, Sarah J.; Samei, Ehsan

    2006-04-15

    Flat panel detectors exhibit improved signal-to-noise ratio (SNR) and display capabilities compared to film. This improvement necessitates a new evaluation of optimal geometry for conventional projection imaging applications such as digital projection mammography as well as for advanced x-ray imaging applications including cone-beam computed tomography (CT), tomosynthesis, and mammotomography. Such an evaluation was undertaken in this study to examine the effects of x-ray source distribution, inherent detector resolution, magnification, scatter rejection, and noise characteristics including noise aliasing. A model for x-ray image acquisition was used to develop generic results applicable to flat panel detectors with similar x-ray absorption characteristics. The model assumed a Gaussian distribution for the focal spot and a rectangular distribution for a pixel. A generic model for the modulated transfer function (MTF) of indirect flat panel detectors was derived by a nonlinear fit of empirical receptor data to the Burgess model for phosphor MTFs. Noise characteristics were investigated using a generic noise power spectrum (NPS) model for indirect phosphor-based detectors. The detective quantum efficiency (DQE) was then calculated from the MTF and NPS models. The results were examined as a function of focal spot size (0.1, 0.3, and 0.6 mm) and pixel size (50, 100, 150, and 200 {mu}m) for magnification ranges 1 to 3. Mammography, general radiography (also applicable to mammotomography), and chest radiography applications were explored using x-ray energies of 28, 74, and 120 kVp, respectively. Nodule detection was examined using the effective point source scatter model, effective DQE, and the Hotelling SNR{sup 2} efficiency. Results indicate that magnification can potentially improve the signal and noise performance of digital images. Results also show that a cross over point occurs in the spatial frequency above and below which the effects of magnification differ

  12. High Brightness Neutron Source for Radiography

    SciTech Connect

    Cremer, J. T.; Piestrup, Melvin, A.; Gary, Charles, K.; Harris, Jack, L. Williams, David, J.; Jones, Glenn, E.; Vainionpaa, J. , H.; Fuller, Michael, J.; Rothbart, George, H.; Kwan, J., W.; Ludewigt, B., A.; Gough, R.., A..; Reijonen, Jani; Leung, Ka-Ngo

    2008-12-08

    This research and development program was designed to improve nondestructive evaluation of large mechanical objects by providing both fast and thermal neutron sources for radiography. Neutron radiography permits inspection inside objects that x-rays cannot penetrate and permits imaging of corrosion and cracks in low-density materials. Discovering of fatigue cracks and corrosion in piping without the necessity of insulation removal is possible. Neutron radiography sources can provide for the nondestructive testing interests of commercial and military aircraft, public utilities and petrochemical organizations. Three neutron prototype neutron generators were designed and fabricated based on original research done at the Lawrence Berkeley National Laboratory (LBNL). The research and development of these generators was successfully continued by LBNL and Adelphi Technology Inc. under this STTR. The original design goals of high neutron yield and generator robustness have been achieved, using new technology developed under this grant. In one prototype generator, the fast neutron yield and brightness was roughly 10 times larger than previously marketed neutron generators using the same deuterium-deuterium reaction. In another generator, we integrate a moderator with a fast neutron source, resulting in a high brightness thermal neutron generator. The moderator acts as both conventional moderator and mechanical and electrical support structure for the generator and effectively mimics a nuclear reactor. In addition to the new prototype generators, an entirely new plasma ion source for neutron production was developed. First developed by LBNL, this source uses a spiral antenna to more efficiently couple the RF radiation into the plasma, reducing the required gas pressure so that the generator head can be completely sealed, permitting the possible use of tritium gas. This also permits the generator to use the deuterium-tritium reaction to produce 14-MeV neutrons with increases

  13. Imaging properties of digital magnification radiography.

    PubMed

    Boyce, Sarah J; Samei, Ehsan

    2006-04-01

    Flat panel detectors exhibit improved signal-to-noise ratio (SNR) and display capabilities compared to film. This improvement necessitates a new evaluation of optimal geometry for conventional projection imaging applications such as digital projection mammography as well as for advanced x-ray imaging applications including cone-beam computed tomography (CT), tomosynthesis, and mammotomography. Such an evaluation was undertaken in this study to examine the effects of x-ray source distribution, inherent detector resolution, magnification, scatter rejection, and noise characteristics including noise aliasing. A model for x-ray image acquisition was used to develop generic results applicable to flat panel detectors with similar x-ray absorption characteristics. The model assumed a Gaussian distribution for the focal spot and a rectangular distribution for a pixel. A generic model for the modulated transfer function (MTF) of indirect flat panel detectors was derived by a nonlinear fit of empirical receptor data to the Burgess model for phosphor MTFs. Noise characteristics were investigated using a generic noise power spectrum (NPS) model for indirect phosphor-based detectors. The detective quantum efficiency (DQE) was then calculated from the MTF and NPS models. The results were examined as a function of focal spot size (0.1, 0.3, and 0.6 mm) and pixel size (50, 100, 150, and 200 microm) for magnification ranges 1 to 3. Mammography, general radiography (also applicable to mammotomography), and chest radiography applications were explored using x-ray energies of 28, 74, and 120 kVp, respectively. Nodule detection was examined using the effective point source scatter model, effective DQE, and the Hotelling SNR2 efficiency. Results indicate that magnification can potentially improve the signal and noise performance of digital images. Results also show that a cross over point occurs in the spatial frequency above and below which the effects of magnification differ

  14. Comparison of conventional radiography and MDCT in suspected scaphoid fractures

    PubMed Central

    Behzadi, Cyrus; Karul, Murat; Henes, Frank Oliver; Laqmani, Azien; Catala-Lehnen, Philipp; Lehmann, Wolfgang; Nagel, Hans-Dieter; Adam, Gerhard; Regier, Marc

    2015-01-01

    AIM: To determine the diagnostic accuracy and radiation dose of conventional radiography and multidetector computed tomography (MDCT) in suspected scaphoid fractures. METHODS: One hundred twenty-four consecutive patients were enrolled in our study who had suffered from a wrist trauma and showed typical clinical symptoms suspicious of an acute scaphoid fracture. All patients had initially undergone conventional radiography. Subsequent MDCT was performed within 10 d because of persisting clinical symptoms. Using the MDCT data as the reference standard, a fourfold table was used to classify the test results. The effective dose and impaired energy were assessed in order to compare the radiation burden of the two techniques. The Wilcoxon test was performed to compare the two diagnostic modalities. RESULTS: Conventional radiography showed 34 acute fractures of the scaphoid in 124 patients (42.2%). Subsequent MDCT revealed a total of 42 scaphoid fractures. The sensitivity of conventional radiography for scaphoid fracture detection was 42.8% and its specificity was 80% resulting in an overall accuracy of 59.6%. Conventional radiography was significantly inferior to MDCT (P < 0.01) concerning scaphoid fracture detection. The mean effective dose of MDCT was 0.1 mSv compared to 0.002 mSv of conventional radiography. CONCLUSION: Conventional radiography is insufficient for accurate scaphoid fracture detection. Regarding the almost negligible effective dose, MDCT should serve as the first imaging modality in wrist trauma. PMID:25628802

  15. Development of Compton radiography using high-Z backlighters produced by ultra-intense lasers

    SciTech Connect

    Tommasini, Riccardo; Park, Hye-Sook; Patel, Prav; Maddox, Brian; Le Pape, Sebastien; Hatchett, Stephen P.; Remington, Bruce A.; Key, Michael H.; Izumi, Nobuhiko; Tabak, Max; Koch, Jeffrey A.; Landen, Otto L.; Hey, Dan; MacKinnon, Andy; Seely, John; Holland, Glenn; Hudson, Larry; Szabo, Csilla

    2007-08-02

    High-energy x-ray backlighters will be valuable for radiography experiments at the National Ignition Facility (NIF), and for radiography of imploded inertial confinement fusion cores using Compton scattering to observe cold, dense plasma. Key considerations are the available backlight brightness, and the backlight size. To quantify these parameters we have characterized the emission from low- and high-Z planar foils irradiated by intense picosecond and femtosecond laser pulses from the TITAN laser facility at Lawrence Livermore National Laboratory. Spectra generated by a sequence of elements from Mo to Pb, spanning the x-ray energy range from 17 keV to 75 keV, have been recorded using a Charged Coupled Device (CCD) in single hit regime and a Dual Crystal Spectrometer (DCS). High-resolution point-projection 2D radiographs have also been recorded on Fuji BaFBr:Eu2 image plates using calibrated resolution grids. We discuss the results in light of the requirements for applications at NIF.

  16. An Overview of the MaRIE X-FEL and Electron Radiography LINAC RF Systems

    SciTech Connect

    Bradley, Joseph Thomas III; Rees, Daniel Earl; Scheinker, Alexander; Sheffield, Richard L.

    2015-05-04

    The purpose of the Matter-Radiation Interactions in Extremes (MaRIE) facility at Los Alamos National Laboratory is to investigate the performance limits of materials in extreme environments. The MaRIE facility will utilize a 12 GeV linac to drive an X-ray Free-Electron Laser (FEL). Most of the same linac will also be used to perform electron radiography. The main linac is driven by two shorter linacs; one short linac optimized for X-FEL pulses and one for electron radiography. The RF systems have historically been the one of the largest single component costs of a linac. We will describe the details of the different types of RF systems required by each part of the linacs. Starting with the High Power RF system, we will present our methodology for the choice of RF system peak power and pulselength with respect to klystron parameters, modulator parameters, performance requirements and relative costs. We will also present an overview of the Low Level RF systems that are proposed for MaRIE and briefly describe their use with some proposed control schemes.

  17. AMMRC (Army Materials and Mechanics Research Center) mobile-accelerator neutron-radiography system operations at US Army Yuma Proving Ground. Interim technical report

    SciTech Connect

    Dance, W.E.; Carollo, S.F.

    1984-04-15

    The mobile neutron radiography system designed and fabricated for the Army Materials and Mechanics Research Center was transported for exploratory evaluation by YPG radiography personnel. Objectives of the field operations were to demonstrate applicability of neutron radiography for inspection of specific Army ordnance items, to provide Army personnel with on-site experience and a data base for defining future neutron radiography and facility requirements, and to evaluate the reliability of this new type of mobile neutron radiography system in a non-laboratory or field environment. Neutron radiographs were compared with X-ray radiographs of the test items. Areas were noted where only the neutron images yielded useful NDI information, and others noted where X-ray is needed. The complementary nature of the results from the two radiographic techniques was well illustrated. Several neutron converter/film combinations were used during the operations to determine the optimum combination for producing good images in reasonable exposure times, using a relatively low-flux system. The system operated reliably during the six weeks period in the non-laboratory environment, and safety of operation of the mobile inspection unit was demonstrated.

  18. Linear induction accelerator approach for advanced radiography

    SciTech Connect

    Caporaso, G.J.

    1997-05-01

    Recent advances in induction accelerator technology make it possible to envision a single accelerator that can serve as an intense, precision multiple pulse x-ray source for advanced radiography. Through the use of solid-state modulator technology repetition rates on the order of 1 MHz can be achieved with beam pulse lengths ranging from 200 ns to 2 {micro}secs. By using fast kickers, these pulses may be sectioned into pieces which are directed to different beam lines so as to interrogate the object under study from multiple lines of sight. The ultimate aim is to do a time dependent tomographic reconstruction of a dynamic object. The technology to accomplish these objectives along with a brief discussion of the experimental plans to verify it will be presented.

  19. Digital radiography exposure indices: A review

    SciTech Connect

    Mothiram, Ursula; Brennan, Patrick C; Lewis, Sarah J; Moran, Bernadette; Robinson, John

    2014-06-15

    Digital radiography (DR) technologies have the advantage of a wide dynamic range compared to their film-screen predecessors, however, this poses a potential for increased patient exposure if left unchecked. Manufacturers have developed the exposure index (EI) to counter this, which provides radiographers with feedback on the exposure reaching the detector. As these EIs were manufacturer-specific, a wide variety of EIs existed. To offset this, the international standardised EI has been developed by the International Electrotechnical Commission (IEC) and the American Association of Physicists in Medicine (AAPM). The purpose of this article is to explore the current literature relating to EIs, beginning with the historical development of the EI, the development of the standardised EI and an exploration of common themes and studies as evidenced in the research literature. It is anticipated that this review will provide radiographers with a useful guide to understanding EIs, their application in clinical practice, limitations and suggestions for further research.

  20. Digital radiography exposure indices: A review

    PubMed Central

    Mothiram, Ursula; Brennan, Patrick C; Lewis, Sarah J; Moran, Bernadette; Robinson, John

    2014-01-01

    Digital radiography (DR) technologies have the advantage of a wide dynamic range compared to their film-screen predecessors, however, this poses a potential for increased patient exposure if left unchecked. Manufacturers have developed the exposure index (EI) to counter this, which provides radiographers with feedback on the exposure reaching the detector. As these EIs were manufacturer-specific, a wide variety of EIs existed. To offset this, the international standardised EI has been developed by the International Electrotechnical Commission (IEC) and the American Association of Physicists in Medicine (AAPM). The purpose of this article is to explore the current literature relating to EIs, beginning with the historical development of the EI, the development of the standardised EI and an exploration of common themes and studies as evidenced in the research literature. It is anticipated that this review will provide radiographers with a useful guide to understanding EIs, their application in clinical practice, limitations and suggestions for further research. PMID:26229645

  1. NBS work on neutron resonance radiography

    SciTech Connect

    Schrack, R.A.

    1987-01-01

    NBS has been engaged in a wide-ranging program in Neutron Resonance Radiography utilizing both one- and two-dimensional position-sensitive neutron detectors. The ability to perform a position-sensitive assay of up to 16 isotopes in a complex matrix has been demonstrated for a wide variety of sample types, including those with high gamma activity. A major part of the program has been the development and application of the microchannel-plate-based position-sensitive neutron detector. This detector system has high resolution and sensitivity, together with adequate speed of response to be used with neutron time-of-flight techniques. This system has demonstrated the ability to simultaneously image three isotopes in a sample with no interference.

  2. Estimated radiation risks associated with endodontic radiography.

    PubMed

    Danforth, R A; Torabinejad, M

    1990-02-01

    Endodontic patients are sometimes concerned about the risks of tumors or cataracts from radiation exposure during root canal therapy. By using established dose and risk information, we calculated the extent of these risks. The chance of getting leukemia from an endodontic x-ray survey using 90 kVp was found to be 1 in 7.69 million, the same as the risk of dying from cancer from smoking 0.94 cigarettes or from an auto accident when driving 3.7 km. Risk of thyroid gland neoplasia was 1 in 667,000 (smoking 11.6 cigarettes, driving 45 km) and risk of salivary gland neoplasia 1 in 1.35 million (smoking 5.4 cigarettes, driving 21.1 km). Use of 70 kVp radiography reduced these risks only slightly. To receive the threshold dose to eyes to produce cataract changes, a patient would have to undergo 10,900 endodontic surveys. PMID:2390963

  3. Measuring microfocus focal spots using digital radiography

    SciTech Connect

    Fry, David A

    2009-01-01

    Measurement of microfocus spot size can be important for several reasons: (1) Quality assurance during manufacture of microfocus tubes; (2) Tracking performance and stability of microfocus tubes; (3) Determining magnification (especially important for digital radiography where the native spatial resolution of the digital system is not adequate for the application); (4) Knowledge of unsharpness from the focal spot alone. The European Standard EN 12543-5 is based on a simple geometrical method of calculating focal spot size from unsharpness of high magnification film radiographs. When determining microfocus focal spot dimensions using unsharpness measurements both signal-to-noise (SNR) and magnification can be important. There is a maximum accuracy that is a function of SNR and therefore an optimal magnification. Greater than optimal magnification can be used but it will not increase accuracy.

  4. Medical radiography examinations and carcinogenic effects.

    PubMed

    Domina, E A

    2014-09-01

    The purpose of the review was the synthesis of the literature data and the results of our radiobiological (biodosimetric) research on the development of radiation-associated tumors as a result of medical radiography (X-ray) diagnostic. Medical X-ray examinations contribute the most to the excess of radiation exposure of the population, much of which is subject to examination to diagnose the underlying disease, the dynamic observation of the patient during treatment, the research of related deseases, and preventative examinations. The review provides arguments for the necessity of developing a more balanced indication for preventative radiological examination of the population in the aftermath of radio-ecological crisis caused by the Chornobyl accident, taking into account the likelihood of radiation carcinogenesis. The problems and tasks of biological (cytogenetic) dosimetry in radiology are formulated. PMID:25536546

  5. Recent developments in digital radiography detectors

    NASA Astrophysics Data System (ADS)

    Yorkston, John

    2007-10-01

    Medical projection radiography is currently undergoing a major transformation into the digital age. New digital X-ray detectors are providing improved image quality as well as increased functionality. These advances promise to significantly change the practice of radiology in the coming years. This review paper will describe some of the issues associated with the new digital detectors, their design, capabilities and limitations as well as a few of the promising new clinical applications being enabled by their introduction. The review will focus mainly on the new amorphous silicon flat-panel detectors but will also touch on other technologies and promising new developments that may be introduced into the clinical environment in the not too distant future.

  6. Direct magnification radiography of the newborn infant

    SciTech Connect

    Brasch, R.C.; Gould, R.G.

    1982-03-01

    Recent advances in technology have made direct radiographic magnification of the newborn infant clinically feasible. A microfocus radiographic tube and a rare-earth, high-speed recording system were combined to obtain more than 2,000 radiographs at magnifications of 2 to 2.5. Special positioning devices permitted imaging of even those infants confined to incubators and connected to life-supporting systems. When quantitatively compared with three conventional contact radiographic systems with respect to resolution, contrast, and noise, magnification radiography showed overall superiority of image characteristics. Definition of subtle abnormalities and anatomically small structures permitted diagnoses which could not be made from conventional images. Furthermore, infant radiation exposure was markedly less (15 mR (3.9 mC/kg) maximum skin exposure) as compared with conventional contact radiographic systems (24 mR(6.1 mC/kg) to 45 mR (11.6 mC/kg)).

  7. Direct magnification radiography of the newborn infant

    SciTech Connect

    Brasch, R.C.; Gould, R.G.

    1982-03-01

    Recent advances in technology have made direct radiographic magnification of the newborn infant clinically feasible. A microfocus radiographic tube and a rare-earth, high-speed recording system were combined to obtain more than 2,000 radiographs at magnifications of 2-2.5. Special positioning devices permitted imaging of even those infants confined to incubators and connected to life-supporting systems. When quantitatively compared with three conventional contact radiographic systems with respect to resolution, contrast, and noise, magnification radiography showed overall superiority of image characteristics. Definition of subtle abnormalities and anatomically small structures permitted diagnoses which could not be made from conventional images. Furthermore, infant radiation exposure was markedly less (15 mR (3.9 mC/kg) maximum skin exposure) as compared with conventional contact radiographic systems (24 mR (6.1 mC/kg) to 45 mR (11.6 mC/kg)).

  8. Coupling High-Energy Radiography And Photon Activation Analysis (PAA) To Optimize The Characterization Of Nuclear Waste Packages

    SciTech Connect

    Carrel, F.; Agelou, M.; Gmar, M.; Laine, F.; Lamotte, T.; Lazaro, D.; Poumarede, B.; Rattoni, B.

    2009-12-02

    Radiological characterization of nuclear waste packages is an industrial issue in order to select the best mode of storage. The alpha-activity, mainly due to the presence of actinides ({sup 235}U, {sup 238}U, {sup 239}Pu,...) inside the package, is one of the most important parameter to assess during the characterization. Photon Activation Analysis (PAA) is a non-destructive active method (NDA method) based on the photofission process and on the detection of delayed particles (neutrons and gammas). This technique is well-adapted to the characterization of large concrete waste packages. However, PAA methods often require a simulation step which is necessary to analyze experimental results and to quantify the global mass of actinides. The weak point of this approach is that characteristics of the package are often not well-known, these latter having a huge impact on the final simulation result. High-energy radiography, based on the use of a linear electron accelerator (LINAC), allows to visualize the content of the package and is also a performing way to tune simulation models and to optimize the characterization process by PAA. In this article, we present high-energy radiography results obtained for two different large concrete waste packages in the SAPHIR facility (Active Photon and Irradiation System). This facility is dedicated to PAA study and development and setup for a decade in CEA Saclay. We also discuss possibilities offered by the coupling between high-energy radiography and PAA techniques.

  9. Image rejects in general direct digital radiography

    PubMed Central

    Rosanowsky, Tine Blomberg; Jensen, Camilla; Wah, Kenneth Hong Ching

    2015-01-01

    Background The number of rejected images is an indicator of image quality and unnecessary imaging at a radiology department. Image reject analysis was frequent in the film era, but comparably few and small studies have been published after converting to digital radiography. One reason may be a belief that rejects have been eliminated with digitalization. Purpose To measure the extension of deleted images in direct digital radiography (DR), in order to assess the rates of rejects and unnecessary imaging and to analyze reasons for deletions, in order to improve the radiological services. Material and Methods All exposed images at two direct digital laboratories at a hospital in Norway were reviewed in January 2014. Type of examination, number of exposed images, and number of deleted images were registered. Each deleted image was analyzed separately and the reason for deleting the image was recorded. Results Out of 5417 exposed images, 596 were deleted, giving a deletion rate of 11%. A total of 51.3% were deleted due to positioning errors and 31.0% due to error in centering. The examinations with the highest percentage of deleted images were the knee, hip, and ankle, 20.6%, 18.5%, and 13.8% respectively. Conclusion The reject rate is at least as high as the deletion rate and is comparable with previous film-based imaging systems. The reasons for rejection are quite different in digital systems. This falsifies the hypothesis that digitalization would eliminates rejects. A deleted image does not contribute to diagnostics, and therefore is an unnecessary image. Hence, the high rates of deleted images have implications for management, training, education, as well as for quality. PMID:26500784

  10. Muscle parameters estimation based on biplanar radiography.

    PubMed

    Dubois, G; Rouch, P; Bonneau, D; Gennisson, J L; Skalli, W

    2016-11-01

    The evaluation of muscle and joint forces in vivo is still a challenge. Musculo-Skeletal (musculo-skeletal) models are used to compute forces based on movement analysis. Most of them are built from a scaled-generic model based on cadaver measurements, which provides a low level of personalization, or from Magnetic Resonance Images, which provide a personalized model in lying position. This study proposed an original two steps method to access a subject-specific musculo-skeletal model in 30 min, which is based solely on biplanar X-Rays. First, the subject-specific 3D geometry of bones and skin envelopes were reconstructed from biplanar X-Rays radiography. Then, 2200 corresponding control points were identified between a reference model and the subject-specific X-Rays model. Finally, the shape of 21 lower limb muscles was estimated using a non-linear transformation between the control points in order to fit the muscle shape of the reference model to the X-Rays model. Twelfth musculo-skeletal models were reconstructed and compared to their reference. The muscle volume was not accurately estimated with a standard deviation (SD) ranging from 10 to 68%. However, this method provided an accurate estimation the muscle line of action with a SD of the length difference lower than 2% and a positioning error lower than 20 mm. The moment arm was also well estimated with SD lower than 15% for most muscle, which was significantly better than scaled-generic model for most muscle. This method open the way to a quick modeling method for gait analysis based on biplanar radiography. PMID:27082150

  11. Development of techniques for the neutron radiography of CF188 flight control surfaces

    NASA Astrophysics Data System (ADS)

    Bennett, L. G. I.; Bickerton, M. L.; Lewis, W. J.

    1999-11-01

    A neutron radiography facility previously installed on the SLOWPOKE-2 research reactor at the Royal Military College of Canada has been used to gain experience with the inspection of flight control surfaces from the CF188 fighter aircraft. Through operating the facility in a temporary manner in terms of handling and shielding for this application, over 500 radiographs were made for more than three aircraft. Moisture and corrosion were discovered in the honeycomb structure and hydration was found in the composite and adhesive layers. The experience also indicated a need to characterize the neutron beam, to decrease the exposure time by finding a faster film and conversion screen combination, and to develop a gauge to evaluate the moisture trapped in the honeycomb cells of flight control surfaces.

  12. 5. INTERIOR VIEW, SHOWING A CONTROL ROOM INSIDE THE RADIOGRAPHY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. INTERIOR VIEW, SHOWING A CONTROL ROOM INSIDE THE RADIOGRAPHY ROOM; PASS-THROUGH FOR EXPOSED FILM ON RIGHT - Fort McCoy, Building No. T-1031, North side of South Tenth Avenue, Block 10, Sparta, Monroe County, WI

  13. Simple methods to reduce patient exposure during scoliosis radiography

    SciTech Connect

    Butler, P.F.; Thomas, A.W.; Thompson, W.E.; Wollerton, M.A.; Rachlin, J.A.

    1986-05-01

    Radiation exposure to the breasts of adolescent females can be reduced significantly through the use of one or all of the following methods: fast, rare-earth screen-film combinations; specially designed compensating filters; and breast shielding. The importance of exposure reduction during scoliosis radiography as well as further details on the above described methods are discussed. In addition, the early results of a Center for Devices and Radiological Health study, which recorded exposure and technique data for scoliosis radiography, is presented.

  14. AIRIX: a new tool for flash radiography in detonics

    NASA Astrophysics Data System (ADS)

    Cavailler, Claude

    2001-04-01

    AIRIX is an induction linear accelerator which will be used for flash radiography in Commissariat A L'Energie Atomique In France. Designed to produce an X-ray dose of some hundreds Rads at 1 meter with an X-ray focal spot size diameter of less than 2 mm (LANL-CEA DAM definition), this facility consists in a 3,8 MeV/2 kA pulsed electron injector and 15,4 MeV induction accelerator powered by 32 high voltage generators. A prototype of this accelerator, called PIVAIR, has been studied and realized in CEA CESTA near Bordeaux. PIVAIR is a validation step for AIRIX at 8 MeV. It includes an injector (3,6 MeV, 3,2 kA, 60 ns) and 16 induction cells supplied by 8 high voltage generators (250 kV, 70 ns). Two different technologies of induction cells have been tested (Rexolite insulator or ferrite Under Vacuum). We have chosen ferrite under vacuum cells technology after comparison of results on beam transport and reliability tests. A focusing experiment at 7.2 MeV of the electron beam has been achieved during summer 1997. We have begun to produce X-rays in October 1997. A dose level of 50 Rad at 1 meter has been achieved with an X-ray spot size diameter of 3.5 to 4 mm (LANL-CEA DAM definition). Static flash radiography of very dense object have been achieved from November 1997 until February 1998. We have been able to test in situ new kinds of very high sensitive X-ray detectors and to check they had reached our very ambitious goals: quantum efficiency at 5 MeV > 50% instead of 1% for luminous screens and film, sensitivity < 10 (mu) Rad (100 time more sensitive than radiographic luminous screens and films), dynamic range > 100, resolution < 2 mm. The AIRIX accelerator has been built in the CEA-MORONVILLIERS test site near Reims under an industrial collaboration with the THOMSON- CSF Company. It is housed in a reinforced concrete bunker and has an overall length of 60 meters. The 20 MeV electron beam has been focused on a 1 mm thick Tantalum target to produce an X-ray fluence of

  15. Water calibration measurements for neutron radiography: Application to water content quantification in porous media

    NASA Astrophysics Data System (ADS)

    Kang, M.; Bilheux, H. Z.; Voisin, S.; Cheng, C. L.; Perfect, E.; Horita, J.; Warren, J. M.

    2013-04-01

    Using neutron radiography, the measurement of water thickness was performed using aluminum (Al) water calibration cells at the High Flux Isotope Reactor (HFIR) Cold-Guide (CG) 1D neutron imaging facility at Oak Ridge National Laboratory, Oak Ridge, TN, USA. Calibration of water thickness is an important step to accurately measure water contents in samples of interest. Neutron attenuation by water does not vary linearly with thickness mainly due to beam hardening and scattering effects. Transmission measurements for known water thicknesses in water calibration cells allow proper correction of the underestimation of water content due to these effects. As anticipated, strong scattering effects were observed for water thicknesses greater than 0.2 cm when the water calibration cells were positioned close to the face of the detector/scintillator (0 and 2.4 cm away, respectively). The water calibration cells were also positioned 24 cm away from the detector face. These measurements resulted in less scattering and this position (designated as the sample position) was used for the subsequent experimental determination of the neutron attenuation coefficient for water. Neutron radiographic images of moist Flint sand in rectangular and cylindrical containers acquired at the sample position were used to demonstrate the applicability of the water calibration. Cumulative changes in the water volumes within the sand columns during monotonic drainage determined by neutron radiography were compared with those recorded by direct reading from a burette connected to a hanging water column. In general, the neutron radiography data showed very good agreement with those obtained volumetrically using the hanging water-column method. These results allow extension of the calibration equation to the quantification of unknown water contents within other samples of porous media.

  16. Water Calibration Measurements for Neutron Radiography: Application to Water Content Quantification in Porous Media

    SciTech Connect

    Kang, Misun; Bilheux, Hassina Z; Voisin, Sophie; Cheng, Chu-lin; Perfect, Edmund; Horita, Juske; Warren, Jeffrey

    2013-04-01

    Using neutron radiography, the measurement of water thickness was performed using aluminum (Al) water calibration cells at the High Flux Isotope Reactor (HFIR) Cold-Guide (CG) 1D neutron imaging facility at Oak Ridge National Laboratory, Oak Ridge, TN, USA. Calibration of water thickness is an important step to accurately measure water contents in samples of interest. Neutron attenuation by water does not vary linearly with thickness mainly due to beam hardening and scattering effects. Transmission measurements for known water thicknesses in water calibration cells allow proper correction of the underestimation of water content due to these effects. As anticipated, strong scattering effects were observed for water thicknesses greater than 2 mm when the water calibration cells were positioned close to the face of the detector / scintillator (0 and 2.4 cm away, respectively). The water calibration cells were also positioned 24 cm away from the detector face. These measurements resulted in less scattering and this position (designated as the sample position) was used for the subsequent experimental determination of the neutron attenuation coefficient for water. Neutron radiographic images of moist Flint sand in rectangular and cylindrical containers acquired at the sample position were used to demonstrate the applicability of the water calibration. Cumulative changes in the water volumes within the sand columns during monotonic drainage determined by neutron radiography were compared with those recorded by direct reading from a burette connected to a hanging water column. In general, the neutron radiography data showed very good agreement with those obtained volumetrically using the hanging water-column method. These results allow extension of the calibration equation to the quantification of unknown water contents within other samples of porous media.

  17. Use and effectiveness of chest radiography and low-back radiography in screening

    SciTech Connect

    Joseph, L.P.; Rachlin, J.A.

    1986-10-01

    One of the Food and Drug Administration's educational programs to optimize the use of medical radiation is the investigation of the efficacy of selected x-ray film examinations. The goal of this program is to provide clinical information needed to aid physicians in their judgment. The routine chest-radiograph screening examination has been studied, and recommendations for five applications of chest-radiograph screening have been published. These recommendations, plus results of FDA research on the efficacy of low-back radiography, are discussed.

  18. Portable Digital Radiography and Computed Tomography Manual

    SciTech Connect

    Not Available

    2007-11-01

    This user manual describes the function and use of the portable digital radiography and computed tomography (DRCT) scanner. The manual gives a general overview of x-ray imaging systems along with a description of the DRCT system. An inventory of the all the system components, organized by shipping container, is also included. In addition, detailed, step-by-step procedures are provided for all of the exercises necessary for a novice user to successfully collect digital radiographs and tomographic images of an object, including instructions on system assembly and detector calibration and system alignment. There is also a short section covering the limited system care and maintenance needs. Descriptions of the included software packages, the DRCT Digital Imager used for system operation, and the DRCT Image Processing Interface used for image viewing and tomographic data reconstruction are given in the appendixes. The appendixes also include a cheat sheet for more experienced users, a listing of known system problems and how to mitigate them, and an inventory check-off sheet suitable for copying and including with the machine for shipment purposes.

  19. [Optimal beam quality for chest digital radiography].

    PubMed

    Oda, Nobuhiro; Tabata, Yoshito; Nakano, Tsutomu

    2014-11-01

    To investigate the optimal beam quality for chest computed radiography (CR), we measured the radiographic contrast and evaluated the image quality of chest CR using various X-ray tube voltages. The contrast between lung and rib or heart increased on CR images obtained by lowering the tube voltage from 140 to 60 kV, but the degree of increase was less. Scattered radiation was reduced on CR images with a lower tube voltage. The Wiener spectrum of CR images with a low tube voltage showed a low value under identical conditions of amount of light stimulated emission. The quality of chest CR images obtained using a lower tube voltage (80 kV and 100 kV) was evaluated as being superior to those obtained with a higher tube voltage (120 kV and 140 kV). Considering the problem of tube loading and exposure in clinical applications, a tube voltage of 90 to 100 kV (0.1 mm copper filter backed by 0.5 mm aluminum) is recommended for chest CR. PMID:25410333

  20. Evaluation and testing of computed radiography systems.

    PubMed

    Charnock, P; Connolly, P A; Hughes, D; Moores, B M

    2005-01-01

    The implementation of film replacement digital radiographic imaging systems throughout Europe is now gathering momentum. Such systems create the foundations for totally digital departments of radiology, since radiographic examinations constitute the most prevalent modality. Although this type of development will lead to improvements in the delivery and management of radiological service, such widespread implementation of new technology must be carefully monitored. The implementation of effective QA tests on installation, at periodic intervals and as part of a routine programme will aid this process. This paper presents the results of commissioning tests undertaken on a number of computed radiography imaging systems provided by different manufacturers. The aim of these tests was not only to provide baseline performance measurements against which subsequent measurements can be compared but also to explore any differences in performance, which might exist between different units. Results of measurements will be presented for (1) monitor and laser printer set-up; (2) imaging plates, including sensitivity, consistency and uniformity; (3) resolution and contrast detectability; and (4) signal and noise performance. Results from the latter are analysed in relationship with both system and quantum noise components. PMID:15933109

  1. Radiography and tomography with polarized neutrons

    NASA Astrophysics Data System (ADS)

    Treimer, Wolfgang

    2014-01-01

    Neutron imaging became important when, besides providing impressive radiographic and tomographic images of various objects, physical, quantification of chemical, morphological or other parameters could be derived from 2D or 3D images. The spatial resolution of approximately 50 µm (and less) yields real space images of the bulk of specimens with more than some cm3 in volume. Thus the physics or chemistry of structures in a sample can be compared with scattering functions obtained e.g. from neutron scattering. The advantages of using neutrons become more pronounced when the neutron spin comes into play. The interaction of neutrons with magnetism is unique due to their low attenuation by matter and because their spin is sensitive to magnetic fields. Magnetic fields, domains and quantum effects such as the Meissner effect and flux trapping can only be visualized and quantified in the bulk of matter by imaging with polarized neutrons. This additional experimental tool is gaining more and more importance. There is a large number of new fields that can be investigated by neutron imaging, not only in physics, but also in geology, archeology, cultural heritage, soil culture, applied material research, magnetism, etc. One of the top applications of polarized neutron imaging is the large field of superconductivity where the Meissner effect and flux pinning can be visualized and quantified. Here we will give a short summary of the results achieved by radiography and tomography with polarized neutrons.

  2. Applications of Cosmic Ray Muon Radiography

    NASA Astrophysics Data System (ADS)

    Guardincerri, E.; Durham, J. M.; Morris, C. L.; Rowe, C. A.; Poulson, D. C.; Bacon, J. D.; Plaud-Ramos, K.; Morley, D. J.

    2015-12-01

    The Dome of Santa Maria del Fiore, Florence Cathedral, was built between 1420 and 1436 by architect Filippo Brunelleschi and it is now cracking under its own weight. Engineering efforts are underway to model the dome's structure and reinforce it against further deterioration. According to some scholars, Brunelleschi might have built reinforcement structures into the dome itself; however, the only confirmed known subsurface reinforcement is a chain of iron and stone around the dome's base. Tomography with cosmic ray muons is a non-destructive imaging method that can be used to image the interior of the wall and therefore ascertain the layout and status of any iron substructure in the dome. We will show the results from a muon tomography measurement of iron hidden in a mockup of the dome's wall performed at Los Alamos National Lab in 2015. The sensitivity of this technique, and the status of this project will be also discussed. At last, we will show results on muon attenuation radiography of larger shallow targets.

  3. Beam characterization at the neutron radiography reactor

    NASA Astrophysics Data System (ADS)

    Morgan, Sarah

    The quality of a neutron imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam's effective length-to-diameter ratio, neutron flux profile, energy spectrum, image quality, and beam divergence, is vital for producing quality radiographic images. This thesis characterized the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam's effective length-to-diameter ratio and image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. Improvement of the existing NRAD MCNP beamline model includes validation of the model's energy spectrum and the development of enhanced image simulation methods. The image simulation methods predict the radiographic image of an object based on the foil reaction rate data obtained by placing a model of the object in front of the image plane in an MCNP beamline model.

  4. A dose monitoring system for dental radiography

    PubMed Central

    Lee, Chena; Kim, Jo-Eun; Symkhampha, Khanthaly; Lee, Woo-Jin; Huh, Kyung-Hoe; Yi, Won-Jin; Heo, Min-Suk; Choi, Soon-Chul; Yeom, Heon-Young

    2016-01-01

    Purpose The current study investigates the feasibility of a platform for a nationwide dose monitoring system for dental radiography. The essential elements for an unerring system are also assessed. Materials and Methods An intraoral radiographic machine with 14 X-ray generators and five sensors, 45 panoramic radiographic machines, and 23 cone-beam computed tomography (CBCT) models used in Korean dental clinics were surveyed to investigate the type of dose report. A main server for storing the dose data from each radiographic machine was prepared. The dose report transfer pathways from the radiographic machine to the main sever were constructed. An effective dose calculation method was created based on the machine specifications and the exposure parameters of three intraoral radiographic machines, five panoramic radiographic machines, and four CBCTs. A viewing system was developed for both dentists and patients to view the calculated effective dose. Each procedure and the main server were integrated into one system. Results The dose data from each type of radiographic machine was successfully transferred to the main server and converted into an effective dose. The effective dose stored in the main server is automatically connected to a viewing program for dentist and patient access. Conclusion A patient radiation dose monitoring system is feasible for dental clinics. Future research in cooperation with clinicians, industry, and radiologists is needed to ensure format convertibility for an efficient dose monitoring system to monitor unexpected radiation dose. PMID:27358817

  5. Comparison of the diagnostic accuracy of direct digital radiography system, filtered images, and subtraction radiography

    PubMed Central

    Takeshita, Wilton Mitsunari; Vessoni Iwaki, Lilian Cristina; Da Silva, Mariliani Chicarelli; Filho, Liogi Iwaki; Queiroz, Alfredo De Franco; Geron, Lucas Bachegas Gomes

    2013-01-01

    Background: To compare the diagnostic accuracy of three different imaging systems: Direct digital radiography system (DDR-CMOS), four types of filtered images, and a priori and a posteriori registration of digital subtraction radiography (DSR) in the diagnosis of proximal defects. Materials and Methods: The teeth were arranged in pairs in 10 blocks of vinyl polysiloxane, and proximal defects were performed with drills of 0.25, 0.5, and 1 mm diameter. Kodak RVG 6100 sensor was used to capture the images. A posteriori DSR registrations were done with Regeemy 0.2.43 and subtraction with Image Tool 3.0. Filtered images were obtained with Kodak Dental Imaging 6.1 software. Images (n = 360) were evaluated by three raters, all experts in dental radiology. Results: Sensitivity and specificity of the area under the receiver operator characteristic (ROC) curve (Az) were higher for DSR images with all three drills (Az = 0.896, 0.979, and 1.000 for drills 0.25, 0.5, and 1 mm, respectively). The highest values were found for 1-mm drills and the lowest for 0.25-mm drills, with negative filter having the lowest values of all (Az = 0.631). Conclusion: The best method of diagnosis was by using a DSR. The negative filter obtained the worst results. Larger drills showed the highest sensitivity and specificity values of the area under the ROC curve. PMID:24124300

  6. A method to optimize the processing algorithm of a computed radiography system for chest radiography.

    PubMed

    Moore, C S; Liney, G P; Beavis, A W; Saunderson, J R

    2007-09-01

    A test methodology using an anthropomorphic-equivalent chest phantom is described for the optimization of the Agfa computed radiography "MUSICA" processing algorithm for chest radiography. The contrast-to-noise ratio (CNR) in the lung, heart and diaphragm regions of the phantom, and the "system modulation transfer function" (sMTF) in the lung region, were measured using test tools embedded in the phantom. Using these parameters the MUSICA processing algorithm was optimized with respect to low-contrast detectability and spatial resolution. Two optimum "MUSICA parameter sets" were derived respectively for maximizing the CNR and sMTF in each region of the phantom. Further work is required to find the relative importance of low-contrast detectability and spatial resolution in chest images, from which the definitive optimum MUSICA parameter set can then be derived. Prior to this further work, a compromised optimum MUSICA parameter set was applied to a range of clinical images. A group of experienced image evaluators scored these images alongside images produced from the same radiographs using the MUSICA parameter set in clinical use at the time. The compromised optimum MUSICA parameter set was shown to produce measurably better images. PMID:17709364

  7. Neutron Radiography and Fission Mapping Measurements of Nuclear Materials with Varying Composition and Shielding

    SciTech Connect

    Mullens, James Allen; McConchie, Seth M; Hausladen, Paul; Mihalczo, John T; Grogan, Brandon R; Sword, Eric D

    2011-01-01

    Neutron radiography and fission mapping measurements were performed on four measurement objects with varying composition and shielding arrangements at the Idaho National Laboratory's Zero Power Physics Reactor (ZPPR) facility. The measurement objects were assembled with ZPPR reactor plate materials comprising plutonium, natural uranium, or highly enriched uranium and were presented as unknowns for characterization. As a part of the characterization, neutron radiography was performed using a deuterium-tritium (D-T) neutron generator as a source of time and directionally tagged 14 MeV neutrons. The neutrons were detected by plastic scintillators placed on the opposite side of the object, using the time-correlation-based data acquisition of the Nuclear Materials Identification System developed at Oak Ridge National Laboratory. Each object was measured at several rotations with respect to the neutron source to obtain a tomographic reconstruction of the object and a limited identification of materials via measurement of the neutron attenuation. Large area liquid scintillators with pulse shape discrimination were used to detect the induced fission neutrons. A fission site map reconstruction was produced by time correlating the induced fission neutrons with each tagged neutron from the D-T neutron generator. This paper describes the experimental configuration, the ZPPR measurement objects used, and the neutron imaging and fission mapping results.

  8. X-ray Radiography and Scattering Diagnosis of Dense Shock-Compressed Matter

    NASA Astrophysics Data System (ADS)

    Lepape, Sebastien

    2009-11-01

    Spectrally resolved x-ray Thomson scattering is an established technique that allows characterizing Fermi degenerate dense plasmas accessible in laser shocked-compressed foil experiments. It has been used in a variety of experiments that, besides measuring plasma density and temperature, served as critical test for models that calculate important plasma parameters like structure factors, bound-free contributions, and ionization energy lowering in warm dense matter. Experiments realized at the TITAN facility at Lawrence Livermore National Laboratory apply ultra-short pulse laser produced K- x rays to characterize plasmas at pressures above 1.5 Mbar that are produced with an energetic nanosecond laser. High energy x-rays produced by the short pulse laser allow probing compressed matter with a high temporal resolution (about 10 ps). From collective and non-collective scattering spectra mass density of the compressed Boron is inferred. X-ray radiography has been used as an independent way to characterize the mass density of matter for identical drive conditions. Here, we use K- X rays in a point projection scheme to probe the shock wave. Densities ranging from 3 to 4 g/cc have been measured, in excellent agreement with the x-ray Thomson scattering data. These radiography data combined with accurate measurement of the Plasmon dispersion in shocked Boron help improving the accuracy of the collision model as well as structure factor calculation.

  9. Visualization of embolism formation in the xylem of liana stems using neutron radiography

    PubMed Central

    Tötzke, Christian; Miranda, Tatiana; Konrad, Wilfried; Gout, Julien; Kardjilov, Nikolay; Dawson, Martin; Manke, Ingo; Roth-Nebelsick, Anita

    2013-01-01

    Background and Aims Cold neutron radiography was applied to directly observe embolism in conduits of liana stems with the aim to evaluate the suitability of this method for studying embolism formation and repair. Potential advantages of this method are a principally non-invasive imaging approach with low energy dose compared with synchrotron X-ray radiation, a good spatial and temporal resolution, and the possibility to observe the entire volume of stem portions with a length of several centimetres at one time. Methods Complete and cut stems of Adenia lobata, Aristolochia macrophylla and Parthenocissus tricuspidata were radiographed at the neutron imaging facility CONRAD at the Helmholtz-Zentrum Berlin für Materialien und Energie, with each measurement cycle lasting several hours. Low attenuation gas spaces were separated from the high attenuation (water-containing) plant tissue using image processing. Key results Severe cuts into the stem were necessary to induce embolism. The formation and temporal course of an embolism event could then be successfully observed in individual conduits. It was found that complete emptying of a vessel with a diameter of 100 µm required a time interval of 4 min. Furthermore, dehydration of the whole stem section could be monitored via decreasing attenuation of the neutrons. Conclusions The results suggest that cold neutron radiography represents a useful tool for studying water relations in plant stems that has the potential to complement other non-invasive methods. PMID:23393096

  10. Proton radiography of laser-driven imploding target in cylindrical geometry

    SciTech Connect

    Volpe, L.; Batani, D.; Vauzour, B.; Nicolai, Ph.; Santos, J. J.; Regan, C.; Dorchies, F.; Fourment, C.; Hulin, S.; Morace, A.; Perez, F.; Baton, S.; Lancaster, K.; Galimberti, M.; Heathcote, R.; Tolley, M.; Spindloe, Ch.; Koester, P.; Labate, L.; Gizzi, L. A.

    2011-01-15

    An experiment was done at the Rutherford Appleton Laboratory (Vulcan laser petawatt laser) to study fast electron propagation in cylindrically compressed targets, a subject of interest for fast ignition. This was performed in the framework of the experimental road map of HiPER (the European high power laser energy research facility project). In the experiment, protons accelerated by a picosecond-laser pulse were used to radiograph a 220 {mu}m diameter cylinder (20 {mu}m wall, filled with low density foam), imploded with {approx}200 J of green laser light in four symmetrically incident beams of pulse length 1 ns. Point projection proton backlighting was used to get the compression history and the stagnation time. Results are also compared to those from hard x-ray radiography. Detailed comparison with two-dimensional numerical hydrosimulations has been done using a Monte Carlo code adapted to describe multiple scattering and plasma effects. Finally we develop a simple analytical model to estimate the performance of proton radiography for given implosion conditions.

  11. An intensified/shuttered cooled CCD camera for dynamic proton radiography

    SciTech Connect

    Yates, G.J.; Albright, K.L.; Alrick, K.R.

    1998-12-31

    An intensified/shuttered cooled PC-based CCD camera system was designed and successfully fielded on proton radiography experiments at the Los Alamos National Laboratory LANSCE facility using 800-MeV protons. The four camera detector system used front-illuminated full-frame CCD arrays (two 1,024 x 1,024 pixels and two 512 x 512 pixels) fiber optically coupled to either 25-mm diameter planar diode or microchannel plate image intensifiers which provided optical shuttering for time resolved imaging of shock propagation in high explosives. The intensifiers also provided wavelength shifting and optical gain. Typical sequences consisting of four images corresponding to consecutive exposures of about 500 ns duration for 40-ns proton burst images (from a fast scintillating fiber array) separated by approximately 1 microsecond were taken during the radiography experiments. Camera design goals and measured performance characteristics including resolution, dynamic range, responsivity, system detection quantum efficiency (DQE), and signal-to-noise will be discussed.

  12. Brighter Screens for Nondestructive Digital X-ray Radiography

    SciTech Connect

    Miller, Jr., A. C.; Bell, Z. W.; Carpenter, D. A.

    2003-09-15

    Fine resolution, bright X-ray screens are needed for digital radiography and material characterization at the Y-12 National Security Complex (Y-12). Current technology is simply not adequate for transferring high-energy X-ray images to visible light for demanding digital applications. Low energy radiography and especially emerging tomographic technologies are severely hampered for Y-12 nondestructive evaluation (NDE) applications by dim screens with poor resolution. Also, the development of more advanced materials characterization techniques, such as electron backscatter diffraction (EBSD), is driven by a design agency desire for tighter specifications and more uniform materials. Brighter screens would allow us to probe materials on a finer scale, leading to a better understanding of material behavior. A number of X-ray screen materials were studied that would be suitable for direct replacement in existing digital imaging systems. Spectroscopic evaluations were first made for a several candidates and indicated that lutetium orthosilicate (LSO) would be a promising candidate for MeV images. A relative comparison of brightness at various energies was then completed which showed that cesium iodide (CsI) could increase brightness by over an order of magnitude. Since image quality is also important for better screens, the resolving capabilities of candidate materials were measured. Resolution measurements were completed at X-ray peak energies up to 420KeV with magnified optical imaging systems, and indicated that LSO and Industrial Quality Incorporated glass (IQI) exhibited higher resolution than the CsI screen. The results give a choice of materials that can be tailored to the particular test under consideration. If high-speed images are necessary and some resolution can be sacrificed, the CsI screen will be a good choice. The screen can be replaced by an IQI or LSO unit if higher resolution is needed later, for instance to focus in on a region of interest. A number of

  13. A benchmark for comparison of dental radiography analysis algorithms.

    PubMed

    Wang, Ching-Wei; Huang, Cheng-Ta; Lee, Jia-Hong; Li, Chung-Hsing; Chang, Sheng-Wei; Siao, Ming-Jhih; Lai, Tat-Ming; Ibragimov, Bulat; Vrtovec, Tomaž; Ronneberger, Olaf; Fischer, Philipp; Cootes, Tim F; Lindner, Claudia

    2016-07-01

    Dental radiography plays an important role in clinical diagnosis, treatment and surgery. In recent years, efforts have been made on developing computerized dental X-ray image analysis systems for clinical usages. A novel framework for objective evaluation of automatic dental radiography analysis algorithms has been established under the auspices of the IEEE International Symposium on Biomedical Imaging 2015 Bitewing Radiography Caries Detection Challenge and Cephalometric X-ray Image Analysis Challenge. In this article, we present the datasets, methods and results of the challenge and lay down the principles for future uses of this benchmark. The main contributions of the challenge include the creation of the dental anatomy data repository of bitewing radiographs, the creation of the anatomical abnormality classification data repository of cephalometric radiographs, and the definition of objective quantitative evaluation for comparison and ranking of the algorithms. With this benchmark, seven automatic methods for analysing cephalometric X-ray image and two automatic methods for detecting bitewing radiography caries have been compared, and detailed quantitative evaluation results are presented in this paper. Based on the quantitative evaluation results, we believe automatic dental radiography analysis is still a challenging and unsolved problem. The datasets and the evaluation software will be made available to the research community, further encouraging future developments in this field. (http://www-o.ntust.edu.tw/~cweiwang/ISBI2015/). PMID:26974042

  14. Recent advances in fast neutron radiography for cargo inspection

    NASA Astrophysics Data System (ADS)

    Sowerby, B. D.; Tickner, J. R.

    2007-09-01

    Fast neutron radiography techniques are attractive for screening cargo for contraband such as narcotics and explosives. Neutrons have the required penetration, they interact with matter in a manner complementary to X-rays and they can be used to determine elemental composition. Compared to neutron interrogation techniques that measure secondary radiation (neutron or gamma-rays), neutron radiography systems are much more efficient and rapid and they are much more amenable to imaging. However, for neutron techniques to be successfully applied to cargo screening, they must demonstrate significant advantages over well-established X-ray techniques. This paper reviews recent developments and applications of fast neutron radiography for cargo inspection. These developments include a fast neutron and gamma-ray radiography system that utilizes a 14 MeV neutron generator as well as fast neutron resonance radiography systems that use variable energy quasi-monoenergetic neutrons and pulsed broad energy neutron beams. These systems will be discussed and compared with particular emphasis on user requirements, sources, detector systems, imaging ability and performance.

  15. Cross table lateral radiography for measurement of acetabular cup version

    PubMed Central

    Gunderson, Ragnhild Beate

    2016-01-01

    Background Appropriate orientation of the acetabular cup is an important factor for long-term results of total hip arthroplasty. For measurement of cup version cross-table lateral radiography is frequently used, but the reliability has been questioned. We compared cross table lateral radiography with computed tomography in patients that had undergone primary total hip arthroplasty. Methods The study was prospectively done in 117 patients (117 hips). At 3 months after total hip replacement the acetabular version was measured by cross table lateral radiography and compared to measurements by computed tomography. Results By cross table lateral radiography acetabular anteversion was on mean 13.9° with a standard deviation of 10.1° as compared to 17.8°±12.6° by computed tomography. Mean difference was −3.8 with a distribution of measurements of ±13 degrees for 95% of the cases. Conclusions Our study shows that cross table radiography provides acceptable information for clinical use, but has limited use for precise analysis of acetabular cup version. PMID:27275482

  16. A software tool for quality assurance of computed/digital radiography (CR/DR) systems

    NASA Astrophysics Data System (ADS)

    Desai, Nikunj; Valentino, Daniel J.

    2011-03-01

    The recommended methods to test the performance of computed radiography (CR) systems have been established by The American Association of Physicists in Medicine, Report No. 93, "Acceptance Testing and Quality Control of Photostimulable Storage Phosphor Imaging Systems". The quality assurance tests are categorized by how frequently they need to be performed. Quality assurance of CR systems is the responsibility of the facility that performs the exam and is governed by the state in which the facility is located. For Example, the New York State Department of Health has established a guide which lists the tests that a CR facility must perform for quality assurance. This study aims at educating the reader about the new quality assurance requirements defined by the state. It further demonstrates an easy to use software tool, henceforth referred to as the Digital Physicist, developed to aid a radiologic facility in conforming with state guidelines and monitoring quality assurance of CR/DR imaging systems. The Digital Physicist provides a vendor independent procedure for quality assurance of CR/DR systems. Further it, generates a PDF report with a brief description of these tests and the obtained results.

  17. Formation and propagation of laser-driven plasma jets in an ambient medium studied with X-ray radiography and optical diagnostics

    SciTech Connect

    Dizière, A.; Pelka, A.; Ravasio, A.; Yurchak, R.; Loupias, B.; Falize, E.; Kuramitsu, Y.; Sakawa, Y.; Morita, T.; Pikuz, S.; Koenig, M.

    2015-01-15

    In this paper, we present experimental results obtained on the LULI2000 laser facility regarding structure and dynamics of astrophysical jets propagating in interstellar medium. The jets, generated by using a cone-shaped target, propagate in a nitrogen gas that mimics the interstellar medium. X-ray radiography as well as optical diagnostics were used to probe both high and low density regions. In this paper, we show how collimation of the jets evolves with the gas density.

  18. A multi-wavelength, high-contrast contact radiography system for the study of low-density aerogel foams

    NASA Astrophysics Data System (ADS)

    Opachich, Y. P.; Koch, J. A.; Haugh, M. J.; Romano, E.; Lee, J. J.; Huffman, E.; Weber, F. A.; Bowers, J. W.; Benedetti, L. R.; Wilson, M.; Prisbrey, S. T.; Wehrenberg, C. E.; Baumann, T. F.; Lenhardt, J. M.; Cook, A.; Arsenlis, A.; Park, H.-S.; Remington, B. A.

    2016-07-01

    A multi-wavelength, high contrast contact radiography system has been developed to characterize density variations in ultra-low density aerogel foams. These foams are used to generate a ramped pressure drive in materials strength experiments at the National Ignition Facility and require precision characterization in order to reduce errors in measurements. The system was used to characterize density variations in carbon and silicon based aerogels to ˜10.3% accuracy with ˜30 μm spatial resolution. The system description, performance, and measurement results collected using a 17.8 mg/cc carbon based JX-6 (C20H30) aerogel are discussed in this manuscript.

  19. A multi-wavelength, high-contrast contact radiography system for the study of low-density aerogel foams.

    PubMed

    Opachich, Y P; Koch, J A; Haugh, M J; Romano, E; Lee, J J; Huffman, E; Weber, F A; Bowers, J W; Benedetti, L R; Wilson, M; Prisbrey, S T; Wehrenberg, C E; Baumann, T F; Lenhardt, J M; Cook, A; Arsenlis, A; Park, H-S; Remington, B A

    2016-07-01

    A multi-wavelength, high contrast contact radiography system has been developed to characterize density variations in ultra-low density aerogel foams. These foams are used to generate a ramped pressure drive in materials strength experiments at the National Ignition Facility and require precision characterization in order to reduce errors in measurements. The system was used to characterize density variations in carbon and silicon based aerogels to ∼10.3% accuracy with ∼30 μm spatial resolution. The system description, performance, and measurement results collected using a 17.8 mg/cc carbon based JX-6 (C20H30) aerogel are discussed in this manuscript. PMID:27475564

  20. Option study of an orthogonal X-ray radiography axis for pRad at LANSCE area C, Los Alamos.

    SciTech Connect

    Oliver, Bryan Velten; Johnson, David L.; Leckbee, Joshua J.; Jones, Peter

    2010-10-01

    We report on an option study of two potential x-ray systems for orthogonal radiography at Area C in the LANSCE facility at Los Alamos National Laboratory. The systems assessed are expected to be near equivalent systems to the presently existing Cygnus capability at the Nevada Test Site. Nominal dose and radiographic resolution of 4 rad (measured at one meter) and 1 mm spot are desired. Both a system study and qualitative design are presented as well as estimated cost and schedule. Each x-ray system analyzed is designed to drive a rod-pinch electron beam diode capable of producing the nominal dose and spot.

  1. Magnifying lens for 800 MeV proton radiography

    SciTech Connect

    Merrill, F. E.; Campos, E.; Espinoza, C.; Hogan, G.; Hollander, B.; Lopez, J.; Mariam, F. G.; Morley, D.; Morris, C. L.; Murray, M.; Saunders, A.; Schwartz, C.; Thompson, T. N.

    2011-10-15

    This article describes the design and performance of a magnifying magnetic-lens system designed, built, and commissioned at the Los Alamos National Laboratory (LANL) for 800 MeV flash proton radiography. The technique of flash proton radiography has been developed at LANL to study material properties under dynamic loading conditions through the analysis of time sequences of proton radiographs. The requirements of this growing experimental program have resulted in the need for improvements in spatial radiographic resolution. To meet these needs, a new magnetic lens system, consisting of four permanent magnet quadrupoles, has been developed. This new lens system was designed to reduce the second order chromatic aberrations, the dominant source of image blur in 800 MeV proton radiography, as well as magnifying the image to reduce the blur contribution from the detector and camera systems. The recently commissioned lens system performed as designed, providing nearly a factor of three improvement in radiographic resolution.

  2. Application of Neutron Radiography to Flow Visualization in Supercritical Water

    NASA Astrophysics Data System (ADS)

    Takenaka, N.; Sugimoto, K.; Takami, S.; Sugioka, K.; Tsukada, T.; Adschiri, T.; Saito, Y.

    Supercritical water is used in various chemical reaction processes including hydrothermal synthesis of metal oxide nano-particles, oxidation, chemical conversion of biomass and plastics. Density of the super critical water is much less than that of the sub-critical water. By using neutron radiography, Peterson et al. have studied salt precipitation processes in supercritical water and the flow pattern in a reverse-flow vessel for salt precipitation, and Balasko et al. have revealed the behaviour of supercritical water in a container. The nano-particles were made by mixing the super critical flow and the sub critical water solution. In the present study, neutron radiography was applied to the flow visualization of the super and sub critical water mixture in a T-junction made of stainless steel pipes for high pressure and temperature conditions to investigate their mixing process. Still images by a CCD camera were obtained by using the neutron radiography system at B4 port in KUR.

  3. Digital radiography for the field: a portable prototype.

    PubMed

    Cho, Kenneth H; Freckleton, Michael W

    2002-01-01

    The US military has been investigating methods for improving radiographic support for field medical operations. The purpose of this project was to develop and test a portable digital radiography (DR) system to determine its feasibility for field operations. A prototype portable digital radiography device was designed and assembled using a commercially available DR sensor. The sensor and necessary hardware were mounted into a ruggedized aluminum case. The device underwent testing in the hospital and field environments. The prototype rapidly provided digital radiographs in a variety of settings. Shortcomings of the device affecting usability and reliable operation were identified. The successful construction and operation of a portable digital radiography prototype shows that such a device is feasible for field applications. The prototype requires further modification and testing to improve its usability and reliability, and to explore other potential applications, both military and civilian. PMID:12105726

  4. Studies of solid propellant combustion with pulsed radiography

    NASA Technical Reports Server (NTRS)

    Godai, T.; Tanemura, T.; Fujiwara, T.; Shimizu, M.

    1987-01-01

    Pulsed radiography was applied to observe solid propellant surface regression during rocket motor operation. Using a 150 KV flash X-ray system manufactured by the Field Emission Corporation and two kinds of film suppliers, images of the propellant surface of a 5 cm diameter end burning rocket motor were recorded on film. The repetition frame rate of 8 pulses per second and the pulse train length of 10 pulses are limited by the capability of the power supply and the heat build up within the X-ray tube, respectively. The experiment demonstrated the effectiveness of pulsed radiography for observing solid propellant surface regression. Measuring the position of burning surface images on film with a microdensitometer, quasi-instantaneous burning rate as a function of pressure and the variation of characteristic velocity with pressure and gas stay time were obtained. Other research items to which pulsed radiography can be applied are also suggested.

  5. Proton Radiography as an electromagnetic field and density perturbation diagnostic

    SciTech Connect

    Mackinnon, A; Patel, P; Town, R; Edwards, M; Phillips, T; Lerner, S; Price, D; Hicks, D; Key, M; Hatchett, S; Wilks, S; King, J; Snavely, R; Freeman, R; Boehlly, T; Koenig, M; Martinolli, E; Lepape, S; Benuzzi-Mounaix, A; Audebert, P; Gauthier, J; Borghesi, M; Romagnani, L; Toncian, T; Pretzler, G; Willi, O

    2004-04-15

    Laser driven proton beams have been used to diagnose transient fields and density perturbations in laser produced plasmas. Grid deflectometry techniques have been applied to proton radiography to obtain precise measurements of proton beam angles caused by electromagnetic fields in laser produced plasmas. Application of proton radiography to laser driven implosions has demonstrated that density conditions in compressed media can be diagnosed with MeV protons. This data has shown that proton radiography can provide unique insight into transient electromagnetic fields in super critical density plasmas and provide a density perturbation diagnostics in compressed matter . PACS numbers: 52.50.Jm, 52.40.Nk, 52.40.Mj, 52.70.Kz

  6. Scattering corrections in neutron radiography using point scattered functions

    NASA Astrophysics Data System (ADS)

    Kardjilov, N.; de Beer, F.; Hassanein, R.; Lehmann, E.; Vontobel, P.

    2005-04-01

    Scattered neutrons cause distortions and blurring in neutron radiography pictures taken at small distances between the investigated object and the detector. This defines one of the most significant problems in quantitative neutron radiography. The quantification of strong scattering materials such as hydrogenous materials—water, oil, plastic, etc.—with a high precision is very difficult due to the scattering effect in the radiography images. The scattering contribution in liquid test samples (H 2O, D 2O and a special type oil ISOPAR L) at different distances between the samples and the detector, the so-called Point Scattered Function (PScF), was calculated with the help of MCNP-4C Monte Carlo code. Corrections of real experimental data were performed using the calculated PScF. Some of the results as well as the correction algorithm will be presented.

  7. [Digital subtraction radiography for the detection of periodontal bone changes].

    PubMed

    Mera, T

    1989-03-01

    This study was performed to evaluate the efficacy of digital subtraction radiography in detecting alveolar bone changes. In order to test the sensitivity of quantitative evaluation by subtraction radiography, a copper equivalent thickness obtained from digitized radiographs was compared with the actual mineral content of bone phantoms with 15 different minerals and 25 bone specimens. Results demonstrated that the copper equivalent thickness correlated well with the actual mineral content (bone phantoms: gamma s = 1.0, bone specimens: gamma s = 0.985). In order to test the ability of digitized subtraction radiography in assessing alveolar bone changes in vivo, subtraction images were compared with histological features. The experimental angular bony defects were treated with conservative periodontal therapy in 3 monkeys. The standardized radiographs were taken longitudinally after therapy, and subtraction images were made from the sequentially obtained radiographs. In addition, for fluorescent histomorphometrical evaluations of new bone formations, the animals were dosed with oxytetracycline, calsein solution and arizarin complex solution. Radiographic and histological evaluations were scheduled to provide healing periods of 2, 3, 4, 5, 6 and 9 weeks after periodontal therapy. Subtraction radiography offered an objective method to follow histological changes of alveolar bone, and the copper equivalent thickness obtained from subtraction radiographs correlated with the histometric bone volume (gamma s = 0.9023, p less than 0.01). The results of these studies indicated that subtraction radiography was useful in monitoring alveolar bone changes associated with periodontal disease and treatment and that the quanitative measurement of periodontal bone changes by subtraction radiography was feasible. PMID:2517790

  8. NEW INSTRUMENTS AND MEASUREMENT METHODS: Medical ion radiography

    NASA Astrophysics Data System (ADS)

    Shafranova, M. G.; Shafranov, M. D.

    1980-06-01

    The aim of this review is to acquaint the reader with the principles and methods of ion radiography—a method of studying the inner structure of an object by using heavy charged particles. Along with the refinement of the traditional x-ray method of diagnostics and the development of a number of new methods, such as positron tomography and nuclear magnetic resonance, and in spite of the great advances attained in x-radiography in recent years, a persistent search continues for new, refined methods. First of all, efforts are directed toward seeking effective methods of early diagnosis of tumor lesions with less danger than in x-radiography. Studies have been conducted in a number of countries in the past decade on the possibility of applying heavy charged particles of relatively high energies for these purposes. Ion radiography enables one to obtain a higher contrast image than x-radiography at lower doses of irradiation, and to differentiate soft tissues and to detect in them anomalies of small dimensions. It opens up the possibility of obtaining new diagnostic information. Theoretical studies in the field of ion radiography and experiments on animals, on human tissues, and in a number of cases, on patients, have shown the promise offered by using ions for diagnosing not only tumors, but also a number of other serious lesions. This new field of study has incorporated the experience of particle and nuclear physics and widely employs its variety of investigational methods. This article also treats problems involving the application of accelerators for ion radiography and specifications for the beam parameters and for the particle detectors. This review gives an account of the advances in this new field of studies and the prospects for its development and the difficulties on the pathway of introducing it into practice.

  9. Diagnostic Ultrasonography of an Ankle Fracture Undetectable by Conventional Radiography: A Case Report

    PubMed Central

    Daniels, Clinton J.; Welk, Aaron B.; Enix, Dennis E.

    2016-01-01

    Objective The purpose of this study is to present diagnostic ultrasonography assessment of an occult fracture in a case of persistent lateral ankle pain. Clinical Features A 35-year-old woman presented to a chiropractic clinic with bruising, swelling, and pain along the distal fibula 3 days following an inversion ankle trauma. Prior radiographic examination at an urgent care facility was negative for fracture. Conservative care over the next week noted improvement in objective findings, but the pain persisted. Intervention and Outcome Diagnostic ultrasonography was ordered to assess her persistent ankle pain and showed a minimally displaced fracture of the fibula 4 cm proximal to the lateral malleolus. The patient was referred to her primary care physician and successfully managed with conservative care. Conclusion In this case, diagnostic ultrasonography was able to identify a Danis-Weber subtype B1 fracture that was missed by plain film radiography. PMID:27069430

  10. A CONCEPTUAL 3-GEV LANSCE LINAC UPGRADE FOR ENHANCED PROTON RADIOGRAPHY

    SciTech Connect

    Garnett, Robert W; Rybarcyk, Lawrence J.; Merrill, Frank E.; O'Hara, James F.; Rees, Daniel E.; Walstrom, Peter L.

    2012-05-14

    A conceptual design of a 3-GeV linac upgrade that would enable enhanced proton radiography at the Los Alamos Neutron Science Center (LANSCE) is presented. The upgrade is based on the use of superconducting accelerating cavities to increase the present LANSCE linac output energy from 800 MeV to 3 GeV. The LANSCE linac currently provides negative hydrogen ion (H{sup -}) and proton (H{sup +}) beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. Required changes to the front-end, the accelerating structures, and to the RF systems to meet the new performance goals, and changes to the existing beam switchyard to maintain operations for a robust user program are also described.

  11. Hugoniot Measurements at Low Pressures in Tin Using 800 MeV proton Radiography

    SciTech Connect

    Schwartz, Cynthia; Hogan, Gary E; King, Nicholas S. P.; Kwiathowski, Kris K.; Mariam, Fesseha G.; Marr-Lyon, Mark; McNeil, Wendy Vogan; Merrill, Frank E.; Morris, Christopher; Rightley, Paul; Saunders, Alexander

    2009-08-05

    A 2cm long 8 mm diameter cylindrical tin target has been shocked to a pressure in the region of the {beta} {yields} {gamma} phase change using a small, low density PETN charge mounted on the opposite side of a stainless steel diaphragm. The density jump and shock velocity were measured radiographically as the shock wave moved through the sample and the pressure dropped, using the proton radiography facility at LANL. This provided a quasi-continuous record of the equations of state along the Hugoniot for the P1 wave from a shock velocity of 3.25 km/sec down to near the sound speed. Edge release effects were removed from the data using tomographic techniques. The data show evidence for a phase transition that extends over a broad pressure range. The data and analysis will be presented.

  12. Spot size measurement of a flash-radiography source using the pinhole imaging method

    NASA Astrophysics Data System (ADS)

    Wang, Yi; Li, Qin; Chen, Nan; Cheng, Jin-Ming; Xie, Yu-Tong; Liu, Yun-Long; Long, Quan-Hong

    2016-07-01

    The spot size of the X-ray source is a key parameter of a flash-radiography facility, and is usually quoted as an evaluation of the resolving power. The pinhole imaging technique is applied to measure the spot size of the Dragon-I linear induction accelerator, by which a two-dimensional spatial distribution of the source spot is obtained. Experimental measurements are performed to measure the spot image when the transportation and focusing of the electron beam are tuned by adjusting the currents of solenoids in the downstream section. The spot size of full-width at half maximum and that defined from the spatial frequency at half peak value of the modulation transfer function are calculated and discussed.

  13. Proton radiography, nuclear cross sections and multiple Coulomb scattering

    SciTech Connect

    Sjue, Sky K.

    2015-11-04

    The principles behind proton radiography including multiple Coulomb scattering are discussed for a purely imaginary square well nucleus in the eikonal approximation. It is found that a very crude model can reproduce the angular dependence of the cross sections measured at 24 GeV/c. The largest differences are ~3% for the 4.56 mrad data, and ~4% for the 6.68 mrad data. The prospect of understanding how to model deterministically high-energy proton radiography over a very large range of energies is promising, but it should be tested more thoroughly.

  14. Radiation Exposure in the NICU: Computed Radiography versus Digital Detector Radiography.

    PubMed

    Oberle, Renee

    2015-01-01

    Medical radiation exposure to pediatric patients has gained national attention in the last few years. New guidelines encourage technologists, managers, radiologists, and equipment manufacturers to tailor imaging to smaller sized patients. With the advent of computed radiography, patient radiation doses have doubled. This literature review addresses how cumulative doses received by highly radiosensitive infants in neonatal intensive care units correspond to similar doses received by infants that later developed radiation induced cancers. While technologist expertise is important for dose management with any receptor technology, converting to digital flat panel detectors can reduce dose to these areas by > 50%, and minimize risks for radiation induced cancers that often do not present until several decades after exposure. PMID:26710555

  15. Measuring microfocal spots using digital radiography

    SciTech Connect

    Fry, David A; Ewert, Uwe

    2009-01-01

    Measurement of microfocus spot size can be important for several reasons: (1) Quality assurance during manufacture of microfocus tubes; (2) Tracking performance and stability of microfocus tubes; (3) Determining magnification is especially important for digital radiography where the native spatial resolution of the digital system is not adequate for the application; and (4) Knowledge of unsharpness from the focal spot alone. The European Standard EN 12543-5 is based on a simple geometrical method of calculating focal spot size from unsharpness of high magnification film radiographs. The following equations are used for the focal spot size measurement: By similar triangles the following equations are presupposed: f/a = U/b and M = (a+b)/a. These equations can be combined to yield the well known expression: U = f(M - 1). Solving for f, f = U/(M-1). Therefore, the focal spot size, f, can be calculated by measuring the radiographic unsharpness and magnification of a known object. This is the basis for these tests. The European standard actually uses one-half of the unsharpness (which are then added together) from both sides of the object to avoid additional unsharpness contributions due to edge transmission unsharpness of the round test object (the outside of the object is measured). So the equation becomes f = (1/2 U{sub 1} + 1/2 U{sub 2})/(M-1). In practice 1/2 U is measured from the 50% to the 90% signal points on the transition profile from ''black'' to ''white,'' (positive image) or attenuated to unattenuated portion of the image. The 50% to 90% points are chosen as a best fit to an assumed Gaussian radiation distribution from the focal spot and to avoid edge transmission effects. 1/2 U{sub 1} + 1/2 U{sub 2} corresponds about to the full width at half height of a Gaussian focal spot. A highly absorbing material (Tungsten, Tungsten Alloy, or Platinum) is used for the object. Either wires or a sphere are used as the object to eliminate alignment issues. One

  16. Common positioning errors in panoramic radiography: A review.

    PubMed

    Rondon, Rafael Henrique Nunes; Pereira, Yamba Carla Lara; do Nascimento, Glauce Crivelaro

    2014-03-01

    Professionals performing radiographic examinations are responsible for maintaining optimal image quality for accurate diagnoses. These professionals must competently execute techniques such as film manipulation and processing to minimize patient exposure to radiation. Improper performance by the professional and/or patient may result in a radiographic image of unsatisfactory quality that can also lead to a misdiagnosis and the development of an inadequate treatment plan. Currently, the most commonly performed extraoral examination is panoramic radiography. The invention of panoramic radiography has resulted in improvements in image quality with decreased exposure to radiation and at a low cost. However, this technique requires careful, accurate positioning of the patient's teeth and surrounding maxillofacial bone structure within the focal trough. Therefore, we reviewed the literature for the most common types of positioning errors in panoramic radiography to suggest the correct techniques. We would also discuss how to determine if the most common positioning errors occurred in panoramic radiography, such as in the positioning of the patient's head, tongue, chin, or body. PMID:24701452

  17. Common positioning errors in panoramic radiography: A review

    PubMed Central

    Rondon, Rafael Henrique Nunes; Pereira, Yamba Carla Lara

    2014-01-01

    Professionals performing radiographic examinations are responsible for maintaining optimal image quality for accurate diagnoses. These professionals must competently execute techniques such as film manipulation and processing to minimize patient exposure to radiation. Improper performance by the professional and/or patient may result in a radiographic image of unsatisfactory quality that can also lead to a misdiagnosis and the development of an inadequate treatment plan. Currently, the most commonly performed extraoral examination is panoramic radiography. The invention of panoramic radiography has resulted in improvements in image quality with decreased exposure to radiation and at a low cost. However, this technique requires careful, accurate positioning of the patient's teeth and surrounding maxillofacial bone structure within the focal trough. Therefore, we reviewed the literature for the most common types of positioning errors in panoramic radiography to suggest the correct techniques. We would also discuss how to determine if the most common positioning errors occurred in panoramic radiography, such as in the positioning of the patient's head, tongue, chin, or body. PMID:24701452

  18. Neutron Radiography Visualization of Solid Particles in Stirring Liquid Metal

    NASA Astrophysics Data System (ADS)

    Sarma, M.; Ščepanskis, M.; Jakovičs, A.; Thomsen, K.; Nikoluškins, R.; Vontobel, P.; Beinerts, T.; Bojarevičs, A.; Platacis, E.

    This paper presents the analysis of the first dynamic neutron radiography experiment that visualized motion of solid particles in liquid metal, which was stirred by a system of four counter-rotating magnets. The paper also contains the quantitative results derived from neutron images: the distribution of particle concentration, number of admixed particles and velocities as functions of the magnet rotation speed.

  19. Neutron radiography and neutron-induced autoradiography for the classroom

    SciTech Connect

    Aderhold, H.C. )

    1992-01-01

    The Cornell 500-kW MARK II TRIGA reactor at the Ward Laboratory of Nuclear Engineering has been used to illustrate the application of neutron radiography (NR) and neutron-induced autoradiography (NIAR) for solving problems in engineering as well as problems in art history. The applications are described in the paper.

  20. Method and Apparatus for Computed Imaging Backscatter Radiography

    NASA Technical Reports Server (NTRS)

    Shedlock, Daniel (Inventor); Meng, Christopher (Inventor); Sabri, Nissia (Inventor); Dugan, Edward T. (Inventor); Jacobs, Alan M. (Inventor)

    2013-01-01

    Systems and methods of x-ray backscatter radiography are provided. A single-sided, non-destructive imaging technique utilizing x-ray radiation to image subsurface features is disclosed, capable of scanning a region using a fan beam aperture and gathering data using rotational motion.

  1. Trichobezoars Detected and Treated Based on Plain Radiography.

    PubMed

    Barrows, Amy; Vachon, Tyler; Campin, Richard C; Ignacio, Romeo C

    2015-10-01

    Bezoars are conglomerations of indigestible material that become trapped in the gastrointestinal tract. We present a case of an 8-year-old female child diagnosed with a gastric bezoar solely on plain radiography and treated with abdominal surgical exploration and removal. In addition, traditional characteristic radiographic findings and treatment options for bezoars found in the current literature are reviewed. PMID:26444484

  2. Radiation-absorbed doses and energy imparted from panoramic tomography, cephalometric radiography, and occlusal film radiography in children

    SciTech Connect

    Bankvall, G.; Hakansson, H.A.

    1982-05-01

    The absorbed doses and energy imparted from radiographic examinations of children, using panoramic tomography (PTG), cephalometric radiography (CPR), and maxillary frontal occlusal overview (FOO), were examined. The absorbed dose at various sites of the head were measured with TL dosimeters in a phantom and in patients. The energy imparted was calculated from measurements of areal exposure using a planparallel ionization chamber. The maximum absorbed doses for panoramic tomography were located around the lateral rotation center, for cephalometric radiography in the left (tube side) parotid region, and for frontal occlusal radiography in the nose. The absorbed doses in the eyes, thyroid gland, and skin are discussed and compared with previous reports and, for the most part, are found to be in agreement. The mean energy imparted from all three examination methods is 5 mJ with about 57 percent from panoramic, 33 percent from cephalometric, and 10 percent from frontal occlusal examinations. The energy imparted from cephalometric radiography can be reduced to about 10 percent with the use of an improved examination technique, leaving panoramic tomography responsible for contributing about 80 percent of the total energy imparted.

  3. A novel approach to determine post mortem interval using neutron radiography.

    PubMed

    Bilheux, Hassina Z; Cekanova, Maria; Vass, Arpad A; Nichols, Trent L; Bilheux, Jean C; Donnell, Robert L; Finochiarro, Vincenzo

    2015-06-01

    One of the most difficult challenges in forensic research is to objectively determine the post-mortem interval (PMI). The accuracy of PMI is critical for determining the timeline of events surrounding a death. Most PMI techniques rely on gross morphological changes of cadavers that are highly sensitive to taphonomic factors. Recent studies have demonstrated that even exhumed individuals exposed to the same environmental conditions with similar PMIs can present different stages of decomposition. After death, tissue undergoes sequential changes consisting of organic and inorganic phase variations, as well as a gradual reduction of tissue water content. Hydrogen (H) is the primary contributor to neutron radiography (NR) contrast in biological specimens because (1) it is the most abundant element in biological tissues and (2) its nucleus scatters thermal and cold neutrons more strongly than any other atomic nucleus. These contrast differences can be advantageous in a forensic context to determine small changes in hydrogen concentrations. Neutron radiography of decaying canine tissues was performed to evaluate the PMI by measuring the changes in H content. In this study, dog cadavers were used as a model for human cadavers. Canine tissues and cadavers were exposed to controlled (laboratory settings, at the University of Tennessee, College of Veterinary Medicine) and uncontrolled (University of Tennessee Anthropology Research Facility) environmental conditions, respectively. Neutron radiographs were supplemented with photographs and histology data to assess the decompositional stages of cadavers. Results demonstrated that the increase in neutron transmission likely corresponded to a decrease in hydrogen content in the tissue, which was correlated with the decay time of the tissue. Tissues depleted in hydrogen were brighter in the neutron transmission radiographs of skeletal muscles, lung, and bone, under controlled conditions. Over a period of 10 days, changes in neutron

  4. A novel approach to determine post mortem interval using neutron radiography

    SciTech Connect

    Bilheux, Hassina Z.; Cekanova, Maria; Vass, Arpad Alexander; Nichols, Trent L.; Bilheux, Jean -Christophe; Donnell, Robert; Finocchiaro, Vincenzo

    2015-03-06

    In this study, neutron radiography (NR) is used non-destructively to measure changes in hydrogen (H) content in decaying tissues as a mean to estimate post-mortem invertal (PMI). After death, tissue undergoes sequential changes consisting of organic and inorganic phase variations, as well as a gradual reduction of tissue water content. H is the primary contributor to NR contrast in biological specimens because (1) it is the most abundant element in biological tissues and (2) its nucleus scatter thermal and cold neutrons more strongly than any other atomic nucleus. These contrast differences can be advantageous in a forensic context to determine small changes in hydrogen concentrations. Dog cadavers were used as a model for human cadavers. Canine tissues and cadavers were exposed to controlled (laboratory settings) and uncontrolled (University of Tennessee Anthropology Research Facility) environmental conditions during putefraction, respectively. Neutron radiographs were supplemented with photographs and histology data to assess the decomposition stage of cadavers. Results demonstrated that the increase in neutron transmission likely corresponded to a decrease in hydrogen content in the tissue, which was correlated with the time of decay of the tissue. Tissues depleted in hydrogen are brighter in the neutron transmission radiographs of skeletal muscles, lung, and bone, under controlled conditions. Over a period of 10 days, changes in neutron transmission through lung and muscle were found to be higher than bone by 8.3%, 7.0 %, and 2.0 %, respectively. Estimation of the PMI was calculated from a natural logarithmic fitting of the NR data. Under controlled conditions, estimation of the PMI was 70% and 63.9 % accurate for bone and lung tissues, while being 1.4% accurate for muscle tissue. All results underestimated the true PMI. In conclusion, neutron radiography can be used for detection of hydrogen changes in decaying tissues to estimate PMI.

  5. A novel approach to determine post mortem interval using neutron radiography

    DOE PAGESBeta

    Bilheux, Hassina Z.; Cekanova, Maria; Vass, Arpad Alexander; Nichols, Trent L.; Bilheux, Jean -Christophe; Donnell, Robert; Finocchiaro, Vincenzo

    2015-03-06

    In this study, neutron radiography (NR) is used non-destructively to measure changes in hydrogen (H) content in decaying tissues as a mean to estimate post-mortem invertal (PMI). After death, tissue undergoes sequential changes consisting of organic and inorganic phase variations, as well as a gradual reduction of tissue water content. H is the primary contributor to NR contrast in biological specimens because (1) it is the most abundant element in biological tissues and (2) its nucleus scatter thermal and cold neutrons more strongly than any other atomic nucleus. These contrast differences can be advantageous in a forensic context to determinemore » small changes in hydrogen concentrations. Dog cadavers were used as a model for human cadavers. Canine tissues and cadavers were exposed to controlled (laboratory settings) and uncontrolled (University of Tennessee Anthropology Research Facility) environmental conditions during putefraction, respectively. Neutron radiographs were supplemented with photographs and histology data to assess the decomposition stage of cadavers. Results demonstrated that the increase in neutron transmission likely corresponded to a decrease in hydrogen content in the tissue, which was correlated with the time of decay of the tissue. Tissues depleted in hydrogen are brighter in the neutron transmission radiographs of skeletal muscles, lung, and bone, under controlled conditions. Over a period of 10 days, changes in neutron transmission through lung and muscle were found to be higher than bone by 8.3%, 7.0 %, and 2.0 %, respectively. Estimation of the PMI was calculated from a natural logarithmic fitting of the NR data. Under controlled conditions, estimation of the PMI was 70% and 63.9 % accurate for bone and lung tissues, while being 1.4% accurate for muscle tissue. All results underestimated the true PMI. In conclusion, neutron radiography can be used for detection of hydrogen changes in decaying tissues to estimate PMI.« less

  6. Patient position verification in ion-beam therapy using ion-beam radiography and fiducial markers

    NASA Astrophysics Data System (ADS)

    Huber, Lucas; Telsemeyer, Julia; Martišíková, Mária; Jäkel, Oliver

    2011-11-01

    The basic rationale for radiation therapy using ion-beams is its high local precision of dose deposition. Therefore accurate patient positioning prior to and during beam application is a crucial part of the therapy. The current standard position verification procedure uses X-ray based imaging before each beam application. The patient is assumed to remain in his position throughout irradiation. Currently there is no monitoring of the patient position or organ movement during treatment. The aim of this study is to investigate the possibility of verifying the position of a fiducial marker during therapy using ion radiography. Some modern ion therapy facilities like the Heidelberg Ion-Beam Therapy Center (HIT), where our measurements were carried out, use scanning pencil beams to apply dose. Exploiting them for imaging allows to solely irradiate regions of interest in the patient's body, e.g. tissue containing medical markers. The advantage of this technique is that it can be performed quickly in turn with therapeutic beam application and irradiates only very little tissue. For our measurements we used conventional medical metal markers embedded in phantom material mimicking body tissue. To image the residual beam we use a Perkin Elmer RID256-L flat panel detector. In an idealized setup the marker contrast was measured to be as high as 60%, which was reduced by a factor of 2-2.5 when the marker was placed at distances to the detector in the phantom material larger than 10 cm. It was shown that applying 2ṡ105 carbon ions suffices to make the markers' position visible in a setup of realistic material thickness and marker depth. While the dose is comparable to X-ray imaging, the irradiated volume and, consequently, also the integral dose is considerably reduced. However, in realistic geometries there are large particle range differences in lateral direction yielding steep signal gradients in the radiography. Thus, the useful image area with unambiguous signal

  7. Health Facilities

    MedlinePlus

    Health facilities are places that provide health care. They include hospitals, clinics, outpatient care centers, and specialized care centers, ... psychiatric care centers. When you choose a health facility, you might want to consider How close it ...

  8. An improved method for profile radiography of piping

    SciTech Connect

    Bell, M.S.; Haupt, J.D.

    1996-07-01

    The Petro-Chemical industry has used profile radiography for more than thirty years to find, and evaluate, corrosion in piping systems. The technique offers a method of ``seeing into`` a piece of pipe. This allows the inspector to see the ``whole picture``. Single point ultrasonic measurements cannot provide this degree of information. Shell`s objective for studying the use of this method centered on optimizing their profile radiography technique to improve accuracy and reproducibility of wall thickness measurements. Accuracy and reproducibility of measurements are particularly important when used to determine corrosion rates. To help achieve this objective, the authors developed an inspection procedure to minimize the more prominent sources of inaccuracies associated with this technique. Along with this procedure, they also developed an associated training program. All of Shell Oil`s Pressure Equipment inspectors and key contract employees have received this training.

  9. Simulation study of Fast Neutron Radiography using GEANT4

    NASA Astrophysics Data System (ADS)

    Bishnoi, S.; Thomas, R. G.; Sarkar, P. S.; Datar, V. M.; Sinha, A.

    2015-02-01

    Fast neutron radiography (FNR) is an important non-destructive technique for the imaging of thick bulk material. We are designing a FNR system using a laboratory based 14 MeV D-T neutron generator [1]. Simulation studies have been carried using Monte Carlo based GEANT4 code to understand the response of the FNR system for various objects. Different samples ranging from low Z, metallic and high Z materials were simulated for their radiographic images. The quality of constructed neutron radiography images in terms of relative contrast ratio and the contrast to noise ratio were investigated for their dependence on various parameters such as thickness, voids inside high/low Z material and also for low Z material hidden behind high Z material. We report here the potential and limitations of FNR for imaging different materials and a few configurations and also the possible areas where FNR can be implemented.

  10. Neutron Radiography of Fluid Flow for Geothermal Energy Research

    NASA Astrophysics Data System (ADS)

    Bingham, P.; Polsky, Y.; Anovitz, L.; Carmichael, J.; Bilheux, H.; Jacobsen, D.; Hussey, D.

    Enhanced geothermal systems seek to expand the potential for geothermal energy by engineering heat exchange systems within the earth. A neutron radiography imaging method has been developed for the study of fluid flow through rock under environmental conditions found in enhanced geothermal energy systems. For this method, a pressure vessel suitable for neutron radiography was designed and fabricated, modifications to imaging instrument setups were tested, multiple contrast agents were tested, and algorithms developed for tracking of flow. The method has shown success for tracking of single phase flow through a manufactured crack in a 3.81 cm (1.5 inch) diameter core within a pressure vessel capable of confinement up to 69 MPa (10,000 psi) using a particle tracking approach with bubbles of fluorocarbon-based fluid as the "particles" and imaging with 10 ms exposures.

  11. Flash radiography with 24 GeV/c protons

    SciTech Connect

    Morris, C. L.; Alrick, K. R.; Buescher, K. L.; Cagliostro, D. J.; Clark, D. A.; Clark, D. J.; Espinoza, C. J.; Ferm, E. N.; Gallegos, R. A.; Gomez, J. J.; Hogan, G. E.; King, N. S. P.; Kwiatkowski, K.; Liljestrand, R. P.; Mariam, F. G.; Merrill, F. E.; Morley, K. B.; Mottershead, C. T.; Murray, M. M.; Pazuchanics, P. D.

    2011-05-15

    The accuracy of density measurements and position resolution in flash (40 ns) radiography of thick objects with 24 Gev/c protons is investigated. A global model fit to step wedge data is shown to give a good description spanning the periodic table. The parameters obtained from the step wedge data are used to predict transmission through the French Test Object (FTO), a test object of nested spheres, to a precision better than 1%. Multiple trials have been used to show that the systematic errors are less than 2%. Absolute agreement between the average radiographic measurements of the density and the known density is 1%. Spatial resolution has been measured to be 200 {mu}m at the center of the FTO. These data verify expectations of the benefits provided by high energy hadron radiography for thick objects.

  12. [Development of breathing chest radiography: study of exposure timing].

    PubMed

    Tanaka, Rie; Sanada, Shigeru; Kobayashi, Takeshi; Suzuki, Masayuki; Matsui, Takeshi; Inoue, Hitoshi

    2003-08-01

    The flat-panel detector (FPD) has been introduced into clinical practice. A modified FPD, which has the ability to obtain dynamic chest radiographs, was introduced into our hospital, and clinical testing is ongoing. Both the inspiratory and expiratory phases have to be included in dynamic chest radiographs. The purpose of this study was to investigate the most appropriate chest radiography signal for observation of the respiratory process. We prepared ten protocol patterns that differed in terms of respiratory phase at X-ray exposure, exposure duration, and signal multiplicity. We also performed preliminary experiments and administered several questionnaires to ten volunteers. The volunteers breathed according to vocal and visual signals, and their respiratory waves were recorded by spirometer. The most appropriate protocol was similar to the method used for conventional chest radiography. PMID:12960952

  13. Monte Carlo Modeling of High-Energy Film Radiography

    SciTech Connect

    Miller, A.C., Jr.; Cochran, J.L.; Lamberti, V.E.

    2003-03-28

    High-energy film radiography methods, adapted in the past to performing specific tasks, must now meet increasing demands to identify defects and perform critical measurements in a wide variety of manufacturing processes. Although film provides unequaled resolution for most components and assemblies, image quality must be enhanced with much more detailed information to identify problems and qualify features of interest inside manufactured items. The work described is concerned with improving current 9 MeV nondestructive practice by optimizing the important parameters involved in film radiography using computational methods. In order to follow important scattering effects produced by electrons, the Monte Carlo N-Particle (MCNP) transport code was used with advanced, highly parallel computer systems. The work has provided a more detailed understanding of latent image formation at high X-ray energies, and suggests that improvements can be made in our ability to identify defects and to obtain much more detail in images of fine features.

  14. AEC set-up optimisation with computed radiography imaging.

    PubMed

    Mazzocchi, S; Belli, G; Busoni, S; Gori, C; Menchi, I; Salucci, P; Taddeucci, A; Zatelli, G

    2005-01-01

    Phototimer set-up is a critical procedure for dose and image quality optimisation in computed radiography (CR) systems. While a conventional radiography automatic exposure control device (AEC) can be calibrated in order to gain a constant optical density on the film independent of beam quality and patient size, CR detectors present a high dynamic range which allows a much larger dose interval, but with different image quality levels. CR leads to a less frequent exam repetition, but may produce quite noisy images if the exposure level on the plate is not correct. The aim of this work is to evaluate the performance of a CR plate (Agfa MD40) in order to optimally calibrate an AEC device. The plate response has been characterised in terms of digital signal, exposure on the plate and signal-to-noise ratio for different beam qualities, in a patient of standard size. PMID:16461503

  15. Radiography and ultrasonic calculation workbooks: installation and use

    SciTech Connect

    Rikard, D; Dolan, K

    2000-03-24

    The radiography and ultrasonic calculation workbooks are intended to assist Level I, II and III NDE personnel in calculations used in routine job applications. These workbooks are an upgraded version of Microsoft Excel{reg_sign} spreadsheets, which were originally set up in October 1988, using a Macintosh Plus{reg_sign} computer and Microsoft Excel{reg_sign} version 1.5. A description of these was released as ''Computerized Calculations for Radiography and Ultrasonics'', UCRL-JC-105419 in November 1990 and published in Materials Evaluation, Volume 49/Number 4, in April 1991. Over the years as Microsoft improved the capabilities of the Excel program to include the abilities to make sketches and to have multiple tabbed pages in a document called a ''workbook'' we have now modified the calculation spreadsheets to include these enhancements. Following is a short description on how to install and use these workbooks on a Macintosh or PC.

  16. The MU-RAY detector for muon radiography of volcanoes

    NASA Astrophysics Data System (ADS)

    Anastasio, A.; Ambrosino, F.; Basta, D.; Bonechi, L.; Brianzi, M.; Bross, A.; Callier, S.; Caputo, A.; Ciaranfi, R.; Cimmino, L.; D'Alessandro, R.; D'Auria, L.; de La Taille, C.; Energico, S.; Garufi, F.; Giudicepietro, F.; Lauria, A.; Macedonio, G.; Martini, M.; Masone, V.; Mattone, C.; Montesi, M. C.; Noli, P.; Orazi, M.; Passeggio, G.; Peluso, R.; Pla-Dalmau, A.; Raux, L.; Rubinov, P.; Saracino, G.; Scarlini, E.; Scarpato, G.; Sekhniaidze, G.; Starodubtsev, O.; Strolin, P.; Taketa, A.; Tanaka, H. K. M.; Vanzanella, A.

    2013-12-01

    The MU-RAY detector has been designed to perform muon radiography of volcanoes. The possible use on the field introduces several constraints. First the electric power consumption must be reduced to the minimum, so that the detector can be solar-powered. Moreover it must be robust and transportable, for what concerns the front-end electronics and data acquisition. A 1 m2 prototype has been constructed and is taking data at Mt. Vesuvius. The detector consists of modules of 32 scintillator bars with wave length shifting fibers and silicon photomultiplier read-out. A dedicated front-end electronics has been developed, based on the SPIROC ASIC. An introduction to muon radiography principles, the MU-RAY detector description and results obtained in laboratory will be presented.

  17. Study of a loop heat pipe using neutron radiography.

    PubMed

    Cimbala, John M; Brenizer, Jack S; Chuang, Abel Po-Ya; Hanna, Shane; Thomas Conroy, C; El-Ganayni, A A; Riley, David R

    2004-10-01

    An explanation is given of what a loop heat pipe (LHP) is, and how it works. It is then shown that neutron imaging (both real time neutron radioscopy and single exposure neutron radiography) is an effective experimental tool for the study of LHPs. Specifically, neutron imaging has helped to identify and correct a cooling water distribution problem in the condenser, and has enabled visualization of two-phase flow (liquid and vapor) in various components of the LHP. In addition, partial wick dry-out, a phenomenon of great importance in the effective operation of LHPs, is potentially identifiable with neutron imaging. It is anticipated that neutron radioscopy and radiography will greatly contribute to our understanding of LHP operation, and will lead to improvement of LHP modeling and design. PMID:15246420

  18. Human performance analysis of industrial radiography radiation exposure events

    SciTech Connect

    Reece, W.J.; Hill, S.G.

    1995-12-01

    A set of radiation overexposure event reports were reviewed as part of a program to examine human performance in industrial radiography for the US Nuclear Regulatory Commission. Incident records for a seven year period were retrieved from an event database. Ninety-five exposure events were initially categorized and sorted for further analysis. Descriptive models were applied to a subset of severe overexposure events. Modeling included: (1) operational sequence tables to outline the key human actions and interactions with equipment, (2) human reliability event trees, (3) an application of an information processing failures model, and (4) an extrapolated use of the error influences and effects diagram. Results of the modeling analyses provided insights into the industrial radiography task and suggested areas for further action and study to decrease overexposures.

  19. Lung nodules detection in chest radiography: image components analysis

    NASA Astrophysics Data System (ADS)

    Luo, Tao; Mou, Xuanqin; Yang, Ying; Yan, Hao

    2009-02-01

    We aimed to evaluate the effect of different components of chest image on performances of both human observer and channelized Fisher-Hotelling model (CFH) in nodule detection task. Irrelevant and relevant components were separated from clinical chest radiography by employing Principal Component Analysis (PCA) methods. Human observer performance was evaluated in two-alternative forced-choice (2AFC) on original clinical images and anatomical structure only images obtained by PCA methods. Channelized Fisher-Hotelling model with Laguerre-Gauss basis function was evaluated to predict human performance. We show that relevant component is the primary factor influencing on nodule detection in chest radiography. There is obvious difference of detectability between human observer and CFH model for nodule detection in images only containing anatomical structure. CFH model should be used more carefully.

  20. Development of backlighting sources for a Compton radiography diagnostic of Inertial Confinement Fusion targets

    SciTech Connect

    Tommasini, R; MacPhee, A; Hey, D; Ma, T; Chen, C; Izumi, N; Unites, W; MacKinnon, A; Hatchett, S P; Remington, B A; Park, H S; Springer, P; Koch, J A; Landen, O L; Seely, J; Holland, G; Hudson, L

    2008-05-07

    We present scaled demonstrations of backlighter sources, emitting Bremsstrahlung x-rays with photon energies above 75 keV, that we will use to record x-ray Compton radiographic snapshots of cold dense DT fuel in inertial confinement fusion implosions at the National Ignition Facility (NIF). In experiments performed at the Titan laser facility at Lawrence Livermore National Laboratory, we measured the source size and the Bremsstrahlung spectrum as a function of laser intensity and pulse length, from solid targets irradiated at 2e17-5e18 W/cm{sup 2} using 2-40 ps pulses. Using Au planar foils we achieved source sizes down to 5.5 {micro}m, and conversion efficiencies of about 1e-3 J/J into x-ray photons with energies in the 75-100 keV spectral range. We can now use these results to design NIF backlighter targets and shielding, and to predict Compton radiography performance as a function of the NIF implosion yield and associated background.

  1. Development of backlighting sources for a Compton radiography diagnostic of inertial confinement fusion targets (invited)

    SciTech Connect

    Tommasini, R.; MacPhee, A.; Hey, D.; Ma, T.; Chen, C.; Izumi, N.; Unites, W.; MacKinnon, A.; Hatchett, S. P.; Remington, B. A.; Park, H. S.; Springer, P.; Koch, J. A.; Landen, O. L.; Seely, John; Holland, Glenn; Hudson, Larry

    2008-10-15

    We present scaled demonstrations of backlighter sources, emitting bremsstrahlung x rays with photon energies above 75 keV, that we will use to record x-ray Compton radiographic snapshots of cold dense DT fuel in inertial confinement fusion implosions at the National Ignition Facility (NIF). In experiments performed at the Titan laser facility at Lawrence Livermore National Laboratory, we measured the source size and the bremsstrahlung spectrum as a function of laser intensity and pulse length from solid targets irradiated at 2x10{sup 17}-5x10{sup 18} W/cm{sup 2} using 2-40 ps pulses. Using Au planar foils we achieved source sizes down to 5.5 {mu}m and conversion efficiencies of about 1x10{sup -13} J/J into x-ray photons with energies in the 75-100 keV spectral range. We can now use these results to design NIF backlighter targets and shielding and to predict Compton radiography performance as a function of the NIF implosion yield and associated background.

  2. Advances in pulsed-power-driven radiography system design.

    SciTech Connect

    Portillo, Salvador; Hinshelwood, David D.; Rovang, Dean Curtis; Cordova, Steve Ray; Oliver, Bryan Velten; Weber, Bruce V.; Welch, Dale Robert; Shelton, Bradley Allen; Sceiford, Matthew E.; Cooperstein, Gerald; Gignac, Raymond Edward; Puetz, Elizabeth A.; Rose, David Vincent; Barker, Dennis L.; Van De Valde, David M.; Droemer, Darryl W.; Wilkins, Frank Lee; Molina, Isidro; Jaramillo, Deanna M.; Swanekamp, Stephen Brian; Commisso, Robert J.; Bailey, Vernon Leslie; Maenchen, John Eric; Johnson, David Lee; Griffin, Fawn A.; Hahn, Kelly Denise; Smith, Ian

    2004-07-01

    Flash x-ray radiography has undergone a transformation in recent years with the resurgence of interest in compact, high intensity pulsed-power-driven electron beam sources. The radiographic requirements and the choice of a consistent x-ray source determine the accelerator parameters, which can be met by demonstrated Induction Voltage Adder technologies. This paper reviews the state of the art and the recent advances which have improved performance by over an order of magnitude in beam brightness and radiographic utility.

  3. PyRAT - python radiography analysis tool (u)

    SciTech Connect

    Temple, Brian A; Buescher, Kevin L; Armstrong, Jerawan C

    2011-01-14

    PyRAT is a radiography analysis tool used to reconstruction images of unknown 1-0 objects. The tool is written in Python and developed for use on LINUX and Windows platforms. The tool is capable of performing nonlinear inversions of the images with minimal manual interaction in the optimization process. The tool utilizes the NOMAD mixed variable optimization tool to perform the optimization.

  4. Optimizing the tonescale display of computed radiography images

    NASA Astrophysics Data System (ADS)

    Huda, Walter; Slone, Richard M.; Hoyle, Beverly A.; Jing, Xhenxue; Honeyman-Buck, Janice C.

    1996-03-01

    Computed radiography (CR) systems transform exposures incident on the imaging plates to image densities using examination specific tonescale display algorithms. A procedure is proposed which permits CR users to optimize these algorithms based on the premise that image contrast should be optimized. This procedure was applied to portable chest x-rays on a medical intensive care unit. Changes made to the display parameters supplied by the manufacturer resulted in an improved quality of the displayed image.

  5. An overexposure in industrial radiography using an 192Ir radionuclide.

    PubMed

    Jalil, A; Molla, M A

    1989-07-01

    An industrial radiographer was accidentally exposed to a high dose of ionizing radiation from an 192Ir source during radiography of weldjoints in gas pipelines. Some symptoms of high radiation exposure occurred immediately after the incident. The clinical effect of skin erythema developed within 7 d, leading to progressive tissue deterioration. The dose to the body was estimated to be about 2-3 Gy, and the dose to the fingertips was approximately 24 Gy. PMID:2526106

  6. Displacement Maps in Taylor Impact Using Speckle Radiography

    NASA Astrophysics Data System (ADS)

    Grantham, S. G.; Braithwaite, C. H.; Proud, W. G.; Williamson, D. M.

    2006-07-01

    A method was developed at the Cavendish Laboratory (Cambridge University) to determine the internal displacement characteristics of a polymer rod undergoing classic Taylor impact. Using a layer of lead filings on the central plane of the rod and Digital Speckle Radiography with flash x-rays it was possible to build up a dynamic displacement map. This technique can be used to derive material properties such as yield strength and provide data for model validation.

  7. Fast neutron radiography research at ANL-W

    SciTech Connect

    Klann, R.T.; Natale, M.D.

    1996-06-01

    Thirty-seven different elements were tested for their suitability as converter screens for direct and indirect fast neutron radiography. The use of commercial X-ray scintillator screens containing YTaO{sub 4}, LaOBr:Tm, YTaO{sub 4}:Nb, YTaO{sub 4}:Tm, CaWO{sub 4}, BaSO{sub 4}:Sr, and GdO{sub 2}S:Tb was also explored for direct fast neutron radiography. For the indirect radiographic process, only one element, holmium, was found to be better than copper. Iron was also found to work as well as copper. All other elements that were tested were inferior to copper for indirect fast neutron radiography. For direct fast neutron radiography, the results were markedly different. Copper was found to be a poor material to sue, as thirty-two of the elements performed better than the copper. Tantalum was found to be the best material to use. Several other materials that also performed remarkably well include, in order of decreasing utility, gold, lutetium, germanium, dysprosium, and thulium. Several interesting results were obtained for the commercial X-ray scintillator screens. Most notably, useful radiographs were produced with all of the various scintillation screens. However, the screens containing YTaO{sub 4}:Nb offered the greatest film densities for the shortest exposure times. Screens using GdSO{sub 4}:Tb provided the best resolution and clearest images at the sacrifice of exposure time. Also, as previous researchers found, scintillator screens offered significantly shorter exposure times than activation foils.

  8. Imaging Brunelleschi's cupola wall using muon scattering radiography

    SciTech Connect

    Guardincerri, Elena

    2015-09-16

    This PowerPoint presentation describes the cupola's structure and current reinforcements, reasoning behind why muon radiography would be helpful. A demonstration project is described where a similar wall was constructed to illustrate the potential benefits to Italian authorities; Requirements and a potential plan were created and collaboration to make it happen was deemed to be possible among LANL, Toshiba, the Parma and Florence Universities and the Opera del Duomo,

  9. Dedicated phantom materials for spectral radiography and CT

    NASA Astrophysics Data System (ADS)

    Shikhaliev, Polad M.

    2012-03-01

    As x-ray imaging technology moves from conventional radiography and computed tomography (CT) to spectral radiography and CT, dedicated phantom materials are needed for spectral imaging. The spectral phantom materials should accurately represent the energy-dependent mass-attenuation coefficients of different types of tissues. Although tissue-equivalent phantom materials were previously developed for CT and radiation therapy applications, these materials are suboptimal for spectral radiography and CT; they are not compatible with contrast agents, do not represent many of the tissue types and do not provide accurate values of attenuation characteristics of tissue. This work provides theoretical framework and a practical method for developing tissue-equivalent spectral phantom materials with a required set of parameters. The samples of the tissue-equivalent spectral phantom materials were developed, tested and characterized. The spectral phantom materials were mixed with iodine, gold and calcium contrast agents and evaluated. The materials were characterized by CT imaging and x-ray transmission experiments. The fabricated materials had nearly identical densities, mass attenuation coefficients, effective atomic numbers and electron densities as compared to corresponding tissue materials presented in the ICRU-44 report. The experimental results have shown good volume uniformity and inter-sample uniformity (repeatability of sample fabrication) of the fabricated materials. The spectral phantom materials were fabricated under laboratory conditions from readily available and inexpensive components. It was concluded that the presented theoretical framework and fabrication method of dedicated spectral phantom materials could be useful for researchers and developers working in the new area of spectral radiography and CT. Independently, the results could also be useful for other applications, such as radiation therapy.

  10. High Energy X-Ray System Specification for the Device Assembly Facility (DAF) at the NNSS

    SciTech Connect

    Fry, David A.

    2012-08-10

    This specification establishes requirements for an X-Ray System to be used at the Device Assembly Facility (DAF) at the Nevada National Security Site (NNSS) to support radiography of experimental assemblies for Laboratory (LANL, LLNL, SNL) programs conducting work at the NNSS.

  11. Proton microscope design for 9 GeV pRad facility

    NASA Astrophysics Data System (ADS)

    Barminova, H. Y.; Turtikov, V. I.

    2016-05-01

    The proton microscope design for 9 GeV proton radiography facility is described. Basic principles of proton microscope development are discussed. Two variants of microscope optical scheme are proposed. Simulation of the proton beam dynamics is carried out, the results showing the possibility to obtain the microscope spatial resolution not worse than 10 μ m.

  12. Multi-energy ZnSe-based radiography against terrorism: theory and experiments

    NASA Astrophysics Data System (ADS)

    Naydenov, Sergey V.; Ryzhikov, Vladimir D.; Smith, Craig F.; Wood, Dennis; Kostioukevitych, Sergey; Lisetska, Elena

    2006-08-01

    Multi-energy radiography is a new direction in non-destructive testing. Its specific feature is separate detection of penetrating radiation in several energy channels. Multi-energy radiography allows quantitative determination of the atomic composition of objects. This is its principal advantage over conventional radiography. In particular, dual-energy radiography allows determination of the effective atomic number of a material with an accuracy of up to 80-90%. Development of three-energy radiography and radiography of higher multiplicity makes it possible to further improve the reconstruction of an object's chemical composition. This presents the possibility, for example, of detection of explosives and other illegal objects in luggage with a reliability approaching 95-98%. These developments can find application not only in anti-terrorist activities, but also in industrial testing and nuclear medicine.

  13. Radiation dose estimation of patients undergoing lumbar spine radiography

    PubMed Central

    Gyekye, Prince Kwabena; Simon, Adu; Geoffrey, Emi-Reynolds; Johnson, Yeboah; Stephen, Inkoom; Engmann, Cynthia Kaikor; Samuel, Wotorchi-Gordon

    2013-01-01

    Radiation dose to organs of 100 adult patients undergoing lumbar spine (LS) radiography at a University Hospital have been assessed. Free in air kerma measurement using an ionization chamber was used for the patient dosimetry. Organ and effective dose to the patients were estimated using PCXMC (version 1.5) software. The organs that recorded significant dose due to LS radiography were lungs, stomach, liver, adrenals, kidney, pancreas, spleen, galbladder, and the heart. It was observed that the stomach recorded the highest dose (48.2 ± 1.2 μGy) for LS anteroposterior (AP). The spleen also recorded the highest dose (41.2 ± 0.5 μGy) for LS lateral (LAT). The mean entrance surface air kerma (ESAK) of LS LAT (122.2 μGy) was approximately twice that of LS AP (76.3 μGy), but the effective dose for both examinations were approximately the same (LS LAT = 8.6 μSv and LS AP = 10.4 μSv). The overall stochastic health effect of radiation to patients due to LS radiography in the University Hospital is independent of the projection of the examination (AP or LAT). PMID:24672153

  14. Proton radiography based on near-threshold Cerenkov radiation

    DOEpatents

    van Bibber, Karl A.; Dietrich, Frank S.

    2003-01-01

    A Cerenkov imaging system for charged particle radiography that determines the energy loss of the charged particle beam passing through an object. This energy loss information provides additional detail on target densities when used with traditional radiographic techniques like photon or x-ray radiography. In this invention a probe beam of 800 MeV to 50 GeV/c charged particles is passed through an object to be imaged, an imaging magnetic spectrometer, to a silicon aerogel Cerenkov radiator where the charged particles emitted Cerenkov light proportional to their velocity. At the same beam focal plane, a particle scintillator produces a light output proportional to the incident beam flux. Optical imaging systems relay the Cerenkov and scintillator information to CCD's or other measurement equipment. A ratio between the Cerenkov and scintillator is formed, which is directly proportional to the line density of the object for each pixel measured. By rotating the object, tomographic radiography may be performed. By applying pulses of beam, discrete time-step movies of dynamic objects may be made.

  15. The use of a radiopaque contrast medium in endodontic radiography.

    PubMed

    Shearer, A C; Wasti, F; Wilson, N H

    1996-03-01

    A series of in vitro studies were carried out to investigate the use and application of a radiopaque contrast medium in conventional periapical dental radiography for the diagnosis and evaluation of root canal systems. The water-soluble radiopaque contrast medium was introduced into the root canals of 30 first permanent maxillary and 30 first permanent mandibular molar teeth. The radiographic images of these teeth with and without radiopaque contrast medium in the root canal systems were compared and contrasted. Further comparisons were made with the same teeth rendered transparent. The results indicate that by standardizing the diagnostic criteria the inter-examiner reliability was in good agreement; it was independent of the radiographic technique used. The validity of the radiographs was enhanced by the use of the radiopaque contrast medium. The results confirm that, with the use of a radiopaque contrast medium, images of root canal systems are easier to read and interpret than plain radiographic images of root canal systems. The use of radiopaque contrast medium in endodontic radiography may be a valuable aid in the diagnosis and evaluation of root canal systems. This system would complement rather than replace plain radiography. PMID:9206431

  16. The implementation of digital sensors in maxillofacial radiography

    NASA Astrophysics Data System (ADS)

    van der Stelt, Paul F.

    2001-03-01

    Systems for intra-oral digital radiography in dentistry can be divided into two main groups: direct sensor systems and semi-direct or indirect sensor systems. Direct imaging is performed by a two-dimensional array of sensor elements. The size of a typical intra-oral CCD-sensor is approximately from 18 mm×24 mm to 30 mm×40 mm; the active area is somewhat smaller, because of the thickness of the packaging of the sensor. CCD-based imaging is now also available for panoramic and cephalometric radiography. Indirect (semi-direct) imaging is based on storage phosphor plates (SPP) imaging. The plate is positioned in the mouth of the patient behind the teeth, and exposed to radiation. The positioning of the sensor plate resembles very much the way conventional radiographic films are handled. SPP technology is also available for panoramic and cephalometric imaging. The purpose of radiography is to provide information to solve a particular diagnostic task. It is therefore very likely that the role of dedicated diagnostic software will become essential in the near future. The importance of dedicated software for diagnostic imaging will increase. As a result of worldwide research, more procedures will become available, for research as well as for use in general practice.

  17. Neutron fan beam source for neutron radiography purpose

    SciTech Connect

    Le Tourneur, P.; Bach, P.; Dance, W. E.

    1999-06-10

    The development of the DIANE neutron radiography system included a sealed-tube neutron generator for this purpose and the optimization of the system's neutron beam quality in terms of divergence and useful thermal neutron yield for each 14-MeV neutron produced. Following this development, the concept of a DIANE fan beam source is herewith introduced. The goal which drives this design is one of economy: by simply increasing the aperture dimension of a conventional DIANE beam in one plane of its collimator axis to a small-angle, fan-shaped output, the useful beam area for neutron radiography would be substantially increased. Thus with the same source, the throughput, or number of objects under examination at any given time, would be augmented significantly. Presented here are the design of this thermal neutron source and the initial Monte Carlo calculations. Taking into account the experience with the conventional DIANE neutron radiography system, these result are discussed and the potential of and interest in such a fan-beam source are explored.

  18. Reduction of radiation exposure during radiography for scoliosis

    SciTech Connect

    Gray, J.E.; Hoffman, A.D.; Peterson, H.A.

    1983-01-01

    To reduce the radiation exposure received by young scoliosis patients during treatment, six changes in technique were instituted: (1) a posteroanterior projection, (2) specially designed leaded acrylic filters, (3) a high-speed screen-film system, (4) a specially designed cassette-holder and grid, (5) a breast-shield, and (6) additional filtration in the x-ray tube the thyroid, breast, and abdominal areas were made on an Alderson phantom. They revealed an eightfold reduction in abdominal exposure for both the posteroanterior and the lateral radiographys. There was a twentyfold reduction in exposure to the thyroid for the posteroanterior radiography from 100 to less than five milliroentgens and for the lateral radiograph there was a 100-fold reduction from 618 to six milliroentgens. For the breasts there was a sixty-ninefold reduction from 344 to less than five milliroentgens for the posteroanterior radiography and a fifty-fivefold reduction from 277 to less than five milliroentgens for the lateral radiograph. These reductions in exposure were obtained without significant loss in the quality of the radiographs and in most instances with an improvement in the over-all quality of the radiograph due to the more uniform exposure.

  19. Z-petawatt driven ion beam radiography development.

    SciTech Connect

    Schollmeier, Marius; Geissel, Matthias; Rambo, Patrick K.; Schwarz, Jens; Sefkow, Adam B.

    2013-09-01

    Laser-driven proton radiography provides electromagnetic field mapping with high spatiotemporal resolution, and has been applied to many laser-driven High Energy Density Physics (HEDP) experiments. Our report addresses key questions about the feasibility of ion radiography at the Z-Accelerator (%E2%80%9CZ%E2%80%9D), concerning laser configuration, hardware, and radiation background. Charged particle tracking revealed that radiography at Z requires GeV scale protons, which is out of reach for existing and near-future laser systems. However, it might be possible to perform proton deflectometry to detect magnetic flux compression in the fringe field region of a magnetized liner inertial fusion experiment. Experiments with the Z-Petawatt laser to enhance proton yield and energy showed an unexpected scaling with target thickness. Full-scale, 3D radiation-hydrodynamics simulations, coupled to fully explicit and kinetic 2D particle-in-cell simulations running for over 10 ps, explain the scaling by a complex interplay of laser prepulse, preplasma, and ps-scale temporal rising edge of the laser.

  20. Fiber Optically Coupled Diode Array Digital Radiography System

    NASA Astrophysics Data System (ADS)

    Sashin, Donald; Sternglass, Ernest J.; Slasky, B. S.; Bron, Klaus M.; Herron, John M.; Kennedy, William H.; Shabason, Leonard; Boyer, Joseph W.; Pollitt, Alma E.; Latchaw, Richard E.

    1982-12-01

    A new type of digital radiography system of very high contrast sensitivity and spatial resolution is described which is based on the use of six linear arrays of self-scanning diodes fiber-optically coupled to a phosphor screen. The high detail of the system results from the fact that 6144 discrete diodes, 1024 per array, scan a field of view of 6 inches wide. A contrast sensitivity five times greater than film is achieved due to the high dynamic range of the diodes combined with the scatter rejection associated with the slit geometry. The entrance radiation exposure per image is 100 mR but could be reduced well below that in the future. Initial clinical experience has demonstrated the advantage of being able to display a single image over a wide range of window levels and window widths at the same time having a high contrast sensitivity in both the dark and light areas of the image. The complete digital radiograph is taken in a second, however the motion unsharpness is held to a minimum by virtue of an effective exposure time of 8 milliseconds. Applications to digital chest radiography and digital intravenous subtraction angiography in over 30 patients have shown the clinical value of this new form of radiography.

  1. Comparison of scanning equalization and conventional chest radiography.

    PubMed

    Wandtke, J C; Plewes, D B

    1989-09-01

    A clinical comparison study of scanning equalization radiography (SER) and conventional chest radiography was performed with the latest prototype SER system. Conventional chest radiography was performed at 120 kVp with Lanex regular screens (Eastman Kodak, Rochester, NY) and Kodak Ortho-G or Ortho-C film (Eastman Kodak). The 253 volunteer patients were examined with both techniques. The chest radiographs were interpreted by four radiologists. The study group was composed of 58 normal and 195 abnormal posteroanterior and lateral chest radiographs. In 31 cases there were two major radiologic diagnoses. The number of correct interpretations increased when the SER images were examined, compared with the conventional Ortho-G (chi 2 = 4.17, P less than .05) and conventional Ortho-C (chi 2 = 16.9, P less than .001) radiographs. The overall accuracy of disease detection improved for all radiologists with the SER system. There was no disease category in which the accuracy of interpretation decreased when the SER system was used. The SER system is a clinically reliable method of improving image quality and increasing diagnostic accuracy. PMID:2772170

  2. Analyzing the effect of geometric factors on designing neutron radiography system.

    PubMed

    Amini, Moharam; Fadaei, Amir Hosein; Gharib, Morteza

    2015-11-01

    Neutron radiography is one of the main applications of research reactors. It is a powerful tool to conduct nondestructive testing of materials. The parameters that affect the quality of a radiographic image must be considered during the design of a neutron radiography system. Hence, this study aims to investigate the effect of geometric factors on the quality of the neutron radiography system. The results show that the performance of the mentioned system can be increased by regulating the geometric factors. PMID:26343340

  3. Reduced radiation-absorbed dose to tissues with partial panoramic radiography for evaluation of third molars.

    PubMed

    Kircos, L T; Eakle, W S; Smith, R A

    1986-05-01

    The radiation-absorbed doses from panoramic radiography, distal molar radiography, and a partial panoramic radiographic technique that exposes only the third molar region to radiation are compared. Doses of radiation to the submandibular salivary gland were comparable by all three techniques, but doses of radiation to the head and neck were reduced greatly by the partial panoramic radiographic technique. Partial panoramic radiography is a diagnostically satisfactory and a radiologically safer technique for evaluation of third molar pathosis than is panoramic or distal molar radiography. PMID:3458783

  4. Reduced radiation-absorbed dose to tissues with partial panoramic radiography for evaluation of third molars

    SciTech Connect

    Kircos, L.T.; Eakle, W.S.; Smith, R.A.

    1986-05-01

    The radiation-absorbed doses from panoramic radiography, distal molar radiography, and a partial panoramic radiographic technique that exposes only the third molar region to radiation are compared. Doses of radiation to the submandibular salivary gland were comparable by all three techniques, but doses of radiation to the head and neck were reduced greatly by the partial panoramic radiographic technique. Partial panoramic radiography is a diagnostically satisfactory and a radiologically safer technique for evaluation of third molar pathosis than is panoramic or distal molar radiography.

  5. Design, construction and characterization of a new neutron beam for neutron radiography at the Tehran Research Reactor

    NASA Astrophysics Data System (ADS)

    Choopan Dastjerdi, M. H.; Khalafi, H.; Kasesaz, Y.; Mirvakili, S. M.; Emami, J.; Ghods, H.; Ezzati, A.

    2016-05-01

    To obtain a thermal neutron beam for neutron radiography applications, a neutron collimator has been designed and implemented at the Tehran Research Reactor (TRR). TRR is a 5 MW open pool light water moderated reactor with seven beam tubes. The neutron collimator is implemented in the E beam tube of the TRR. The design of the neutron collimator was performed using MCNPX Monte Carlo code. In this work, polycrystalline bismuth and graphite have been used as a gamma filter and an illuminator, respectively. The L/D parameter of the facility was chosen in the range of 150-250. The thermal neutron flux at the image plane can be varied from 2.26×106 to 6.5×106 n cm-2 s-1. Characterization of the beam was performed by ASTM standard IQI and foil activation technique to determine the quality of neutron beam. The results show that the obtained neutron beam has a good quality for neutron radiography applications.

  6. Study of material changes of SINQ target rods after long-term exposure by neutron radiography methods.

    PubMed

    Lehmann, E E; Vontobel, P; Estermann, M

    2004-10-01

    This paper describes the results of non-destructive investigations by indirect neutron radiography methods obtained at the facility NEUTRA [Nondestruct. Testing Eval. 16 (2000b) 203], spallation neutron source SINQ [Operating experience and development projects at SINQ, PSI Report 98-04, ISSN 1019-0643]. Target rods from the second SINQ metal target were removed after 6 Ah of proton beam exposure and studied under well-shielded conditions. No real damage was found at one of the 11 observed rods and one tube. However, hydrogen accumulation could be identified inside the zircaloy rods and the steel rods as well. Whereas the hydrogen has a homogenous distribution in Zr (with the peak value near the centre of the applied beam), the steel samples show clusters of hydrogen near the edge of the Zr cladding. Lead (in steel cladding) was found modified by accumulations of spallation products, mainly mercury. In the radiography images, a depression of the neutron field was observed due to the absorption by mercury. The applied method with Dy and In as neutron converters and imaging plates [Nucl. Instrum. Methods 377 (1996) 119] as secondary detectors seems to be optimal for such kind of investigations, especially when quantitative considerations have to be made. PMID:15246406

  7. RCRA FACILITIES

    EPA Science Inventory

    Points represent facilities that are regulated by the EPA under the Resource Conservation and Recovery Act (RCRA). Facilities regulated under RCRA generate, dispose of, treate or transport hazardous waste. RCRA is a law enacted by Congress in 1976 and amended in 1984 to include ...

  8. Spectroscopic neutron radiography for a cargo scanning system

    NASA Astrophysics Data System (ADS)

    Rahon, Jill; Danagoulian, Areg; MacDonald, Thomas D.; Hartwig, Zachary S.; Lanza, Richard C.

    2016-06-01

    Detection of cross-border smuggling of illicit materials and contraband is a challenge that requires rapid, low-dose, and efficient radiographic technology. The work we describe here is derived from a technique which uses monoenergetic gamma rays from low energy nuclear reactions, such as 11B(d,nγ)12C, to perform radiographic analysis of shipping containers. Transmission ratios of multiple monoenergetic gamma lines resulting from several gamma producing nuclear reactions can be employed to detect materials of high atomic number (Z), the details of which will be described in a separate paper. Inherent in this particular nuclear reaction is the production of fast neutrons which could enable neutron radiography and further characterization of the effective-Z of the cargo, especially within the range of lower Z. Previous research efforts focused on the use of total neutron counts in combination with X-ray radiography to characterize the hydrogenous content of the cargo. We present a technique of performing transmitted neutron spectral analysis to reconstruct the effective Z and potentially the density of the cargo. This is made possible by the large differences in the energy dependence of neutron scattering cross-sections between hydrogenous materials and those of higher Z. These dependencies result in harder transmission spectra for hydrogenous cargoes than those of non-hydrogenous cargoes. Such observed differences can then be used to classify the cargo based on its hydrogenous content. The studies presented in this paper demonstrate that such techniques are feasible and can provide a contribution to cargo security, especially when used in concert with gamma radiography.

  9. Development of Nuclear Emulsion Detector for Muon Radiography

    NASA Astrophysics Data System (ADS)

    Nishio, A.; Morishima, K.; Kuwabara, K.; Nakamura, M.

    Muon radiography is the non-destructive testing technique of large-scale constructions with cosmic ray muon. Cosmic ray muon has high penetrating power and it always comes from the whole sky. In the same way of taking a X-ray photograph, we can obtain integrated density of constructions which thickness are several tens to several hundreds. We had ever applied this technique to nuclear reactors, volcanos, and so on. Nuclear emulsion is three dimensional track detector with micrometric position accuracy. Thanks to high position resolution, Nuclear emulsion has mrad angular resolution. In addition, the features which require no power supply and can observe in a large area suitable for muon radiography. In Nagoya University, we launched emulsion manufacturing equipment at 2010. It has become possible to flexible development of our detector and succeeded to development of high sensitive nuclear emulsion film (Nagoya emulsion). An important factor is the temperature characteristic to withstand the outdoor observation as a detector to be used in the muon radiography. There is a phenomenon of a latent image fading, whichit is well known in the photographic industry, and this phenomenon is known that temperature and water are involved. So we examined temperature and humidity characteristic of latent image fading about Nagoya emulsion. As a result, we found latent image fading is strongly depends on both temperature and humidity. By dehydrating emulsion film in RH8%, over 95% (Grain Density>40) detection efficiency of muon track keeps over 3months in 25degree, for 2months in 35degree. Additionally it was showed in this test that increasing back ground noise "fog", which may have occurred by sealing emulsion film in a narrow space, is reduced by buffer space in the bag.

  10. Average Soil Water Retention Curves Measured by Neutron Radiography

    SciTech Connect

    Cheng, Chu-Lin; Perfect, Edmund; Kang, Misun; Voisin, Sophie; Bilheux, Hassina Z; Horita, Juske; Hussey, Dan

    2011-01-01

    Water retention curves are essential for understanding the hydrologic behavior of partially-saturated porous media and modeling flow transport processes within the vadose zone. In this paper we report direct measurements of the main drying and wetting branches of the average water retention function obtained using 2-dimensional neutron radiography. Flint sand columns were saturated with water and then drained under quasi-equilibrium conditions using a hanging water column setup. Digital images (2048 x 2048 pixels) of the transmitted flux of neutrons were acquired at each imposed matric potential (~10-15 matric potential values per experiment) at the NCNR BT-2 neutron imaging beam line. Volumetric water contents were calculated on a pixel by pixel basis using Beer-Lambert s law after taking into account beam hardening and geometric corrections. To remove scattering effects at high water contents the volumetric water contents were normalized (to give relative saturations) by dividing the drying and wetting sequences of images by the images obtained at saturation and satiation, respectively. The resulting pixel values were then averaged and combined with information on the imposed basal matric potentials to give average water retention curves. The average relative saturations obtained by neutron radiography showed an approximate one-to-one relationship with the average values measured volumetrically using the hanging water column setup. There were no significant differences (at p < 0.05) between the parameters of the van Genuchten equation fitted to the average neutron radiography data and those estimated from replicated hanging water column data. Our results indicate that neutron imaging is a very effective tool for quantifying the average water retention curve.

  11. Characterization of non-tuberculosis mycobacteria by neutron radiography.

    PubMed

    da Silva, Jaqueline M; Crispim, Verginia Reis; da Silva, Marlei Gomes; Furtado, Vanessa Rodrigues; Duarte, Rafael Da Silva

    2013-07-01

    The genus Mycobacterium shares many characteristics with Corynebacterium and Actinomyces genera, among which the genomic guanine plus cytosine content and the production of long branched-chain fatty acids, known as mycolic acids are enhanced. Growth rate and optimal temperature of mycobacteria are variable. The genus comprises more than 140 known species; however Mycobacterium fortuitum, a fast growing nontuberculous mycobacterium, is clinically significant, because it has been associated to several lesions following surgery procedures such as liposuction, silicone breast and pacemaker implants, exposure to prosthetic materials besides sporadic lesions in the skin, soft tissues and rarely lungs. The objective of the present study is to reduce the time necessary for M. fortuitum characterization based on its morphology and the use of the neutron radiography technique substituting the classical biochemical assays. We also aim to confirm the utility of dendrimers as boron carriers. The samples were sterilized through conventional protocols using 10% formaldehyde. In the incubation process, two solutions with different molar ratios (10:1 and 20:1) of sodium borate and PAMAM G4 dendrimer and also pure sodium borate were used. After doping and sterilization procedures, the samples were deposited on CR-39 sheets, irradiated with a 4.6×10(5) n/cm(2)s thermal neutron flux for 30 min, from the J-9 irradiation channel of the Argonauta IEN/CNEN reactor. The images registered in the CR-39 were visualized in a Nikon E400 optical transmission microscope and captured by a Nikon Coolpix 995 digital camera. Developing the nuclear tracks registered in the CR-39 allowed a 1000× enlargement of mycobacterium images, facilitating their characterization, the use of more sophisticated equipment not being necessary. The use of neutron radiography technique reduced the time necessary for characterization. Doping with PAMAM dendrimer improved the visualization of NTM in neutron radiography

  12. Implementation of a PACS for radiography training and clinical service in a university setting through a multinational effort

    NASA Astrophysics Data System (ADS)

    Tang, Fuk-hay; Law, Yuen Y.; Zhang, Jianguo; Liu, Hai L.; Chang, Tony; Matsuda, Koyo; Cao, Fei

    2001-08-01

    The Hong Kong Polytechnic University has a Radiography Division under the Development of Optometry and Radiography. The Division trains both diagnostic and therapeutic radiographers with 60 students/year and offers a B.Sc. degree. In addition the Division together with the University Health Service operates a radiography clinic with radiology consultation from radiologists from other hospitals and clinics. This paper describers the implementation of a PACS in the Division for radiography training, and for clinical service.

  13. 42 CFR 37.44 - Approval of radiographic facilities that use digital radiography systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... (45 CFR Part 160 and Subparts A, C, and E of Part 164). ... quality digital chest radiographs by submitting to NIOSH digital radiographic image files of a test object... digital radiographic image files from six or more sample chest radiographs that are of acceptable...

  14. 42 CFR 37.44 - Approval of radiographic facilities that use digital radiography systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS SPECIFICATIONS FOR MEDICAL EXAMINATIONS OF... quality digital chest radiographs by submitting to NIOSH digital radiographic image files of a test object... digital radiographic image files from six or more sample chest radiographs that are of acceptable...

  15. 10 CFR 34.61 - Records of the specific license for industrial radiography.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Records of the specific license for industrial radiography. 34.61 Section 34.61 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping Requirements §...

  16. 10 CFR 34.61 - Records of the specific license for industrial radiography.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Records of the specific license for industrial radiography. 34.61 Section 34.61 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping Requirements §...

  17. 10 CFR 34.61 - Records of the specific license for industrial radiography.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Records of the specific license for industrial radiography. 34.61 Section 34.61 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping Requirements §...

  18. 10 CFR 34.61 - Records of the specific license for industrial radiography.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records of the specific license for industrial radiography. 34.61 Section 34.61 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping Requirements §...

  19. 10 CFR 34.61 - Records of the specific license for industrial radiography.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Records of the specific license for industrial radiography. 34.61 Section 34.61 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping Requirements §...

  20. Dual Use Corrosion Inhibitor and Penetrant for Anomaly Detection in Neutron/X Radiography

    NASA Technical Reports Server (NTRS)

    Hall, Phillip B. (Inventor); Novak, Howard L. (Inventor)

    2004-01-01

    A dual purpose corrosion inhibitor and penetrant composition sensitive to radiography interrogation is provided. The corrosion inhibitor mitigates or eliminates corrosion on the surface of a substrate upon which the corrosion inhibitor is applied. In addition, the corrosion inhibitor provides for the attenuation of a signal used during radiography interrogation thereby providing for detection of anomalies on the surface of the substrate.

  1. 78 FR 46618 - Order Prohibiting Operation of Aerotest Radiography and Research Reactor

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ... COMMISSION Order Prohibiting Operation of Aerotest Radiography and Research Reactor I. Aerotest Operations... Radiography and Research Reactor (ARRR) in accordance with the conditions specified therein. The ARRR is... and Research and Development,'' of the AEA and 10 CFR 50.38, ``Ineligibility of Certain...

  2. 75 FR 39985 - In the Matter of Aerotest Operations, Inc. (Aerotest Radiography and Research Reactor); Order...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-13

    ..., use and operation of the Aerotest Radiography and Research Reactor (ARRR) located in San Ramon... the Federal Register on May 14, 2010; 75 FR 27368. No hearing requests or written comments were... COMMISSION In the Matter of Aerotest Operations, Inc. (Aerotest Radiography and Research Reactor);...

  3. 75 FR 57080 - In the Matter of Aerotest Operations, Inc. (Aerotest Radiography and Research Reactor); Order...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-17

    ... which authorizes the possession, use, and operation of the Aerotest Radiography and Research Reactor... COMMISSION In the Matter of Aerotest Operations, Inc. (Aerotest Radiography and Research Reactor); Order... Regulations (10 CFR) Section 50.21(c) for research and development purposes. Aerotest is a wholly...

  4. Computers in dental radiography: a scenario for the future

    SciTech Connect

    Webber, R.L.

    1985-09-01

    The recent emergence of cost-effective computing power makes it possible to integrate sophisticated data-sampling and image-interpretation techniques into dental radiography for the first time. A prototype system is being developed to permit clinical information expressed in three dimensions--plus time--to be made visible almost instantly. The associated X-ray dose for a complete three-dimensional survey of a selected dental region is predicted to be less than that required for a single conventional periapical radiograph exposed on D-speed film.

  5. X-ray vector radiography imaging for biomedical applications

    NASA Astrophysics Data System (ADS)

    Potdevin, Guillaume; Malecki, Andreas; Biernath, Thomas; Bech, Martin; Pfeiffer, Franz

    2012-07-01

    The non-invasive estimation of fracture risk in osteoporosis remains a challenge in the clinical routine and is mainly based on an assessment of bone density by dual X-ray absorption (DXA) although bone micro-architecture is known to play an important role for bone fragility. Here we report on 'X-ray vector Radiography' measurements able to provide a direct bone microstructure diagnostics on human bone samples, which we compare qualitatively and quantitatively with numerical analysis of high resolution radiographs.

  6. DIGITAL RADIOGRAPHY OF SPECIAL NUCLEAR MATERIAL TEST PACKAGES

    SciTech Connect

    HOWARD, BOYD

    2006-02-02

    The purpose of this document is to provide a brief introduction to digital radiography (DR), and a description of the DR configuration that was used to radiographically image the Special Nuclear Material (SNM) Test Packages before and after function tests that have been conducted. Also included are (1) Attachment 1, a comprehensive index that describes at which phase of the certification process that digital radiographic images were acquired, (2) digital radiographic images of each of the six packages at various stages of the certification process, and (3) Attachment 2, imaging instructions, that specify the setup procedures and detailed parameters of the DR imaging methodology that were used.

  7. Proton Radiography: Cross Section Measurements and Detector Development

    SciTech Connect

    Michael J. Longo

    2003-12-17

    OAK-B135 The physics goal of this project is to measure forward production of neutrons and photons produced by high-energy proton beams striking a variety of targets. This will provide data essential to proton radiography. This work is being carried out in conjunction with the Fermilab Experiment 907 (MIPP) collaboration including physicists from Lawrence Livermore Laboratory. Our group is responsible for the E907 forward neutron/photon calorimeter. The project is on track to meet its technical milestones, though the overall schedule at Fermilab has slipped. The electromagnetic calorimeter and the hadron calorimeter were both assembled and ready for testing with beam in December 2003.

  8. X-ray vector radiography imaging for biomedical applications

    SciTech Connect

    Potdevin, Guillaume; Malecki, Andreas; Biernath, Thomas; Bech, Martin; Pfeiffer, Franz

    2012-07-31

    The non-invasive estimation of fracture risk in osteoporosis remains a challenge in the clinical routine and is mainly based on an assessment of bone density by dual X-ray absorption (DXA) although bone micro-architecture is known to play an important role for bone fragility. Here we report on 'X-ray vector Radiography' measurements able to provide a direct bone microstructure diagnostics on human bone samples, which we compare qualitatively and quantitatively with numerical analysis of high resolution radiographs.

  9. Absorbed radiation by various tissues during simulated endodontic radiography.

    PubMed

    Torabinejad, M; Danforth, R; Andrews, K; Chan, C

    1989-06-01

    The amount of absorbed radiation by various organs was determined by placing lithium fluoride thermoluminescent chip dosimeters at selected anatomical sites in and on a human-like X-ray phantom and exposing them to radiation at 70- and 90-kV X-ray peaks during simulated endodontic radiography. The mean exposure dose was determined for each anatomical site. The results show that endodontic X-ray doses received by patients are low when compared with other radiographic procedures. PMID:2592879

  10. BBU design of linear induction accelerator cells for radiography application

    SciTech Connect

    Shang, C.C.; Chen, Y.J.; Gaporaso, G.J.; Houck, T.L.; Molau, N.E.; Focklen, J.; Gregory, S.

    1997-05-06

    There is an ongoing effort to develop accelerating modules for high-current electron accelerators for advanced radiography application. Accelerating modules with low beam-cavity coupling impedances along with gap designs with acceptable field stresses comprise a set of fundamental design criteria. We examine improved cell designs which have been developed for accelerator application in several radiographic operating regimes. We evaluate interaction impedances, analyze the effects of beam structure coupling on beam dynamics (beam break-up instability and corkscrew motion). We also provide estimates of coupling through interesting new high-gradient insulators and evaluate their potential future application in induction cells.

  11. Novel detectors for fast-neutron resonance radiography

    NASA Astrophysics Data System (ADS)

    Vartsky, D.; Mor, I.; Goldberg, M. B.; Bar, D.; Feldman, G.; Dangendorf, V.; Tittelmeier, K.; Weierganz, M.; Bromberger, B.; Breskin, A.

    2010-11-01

    We describe the concept and properties of a time-resolved integrative optical neutron (TRION) detector, a novel high spatial resolution neutron imaging system in the energy range of 1-10 MeV, for fast-neutron resonance radiography (FNRR), with multiple-energy TOF-spectrometry capability. Two generations of TRION detectors have already demonstrated their suitability for detecting small quantities of thin-sheet explosives. TRION holds promise for fully automatic detection and identification of standard and improvised explosives concealed in luggage and cargo, by determining the density distribution of light elements such as C, N and O.

  12. Developments in Dual-Energy Single-Exposure Chest Radiography.

    NASA Astrophysics Data System (ADS)

    Ho, Jung-Tsuoe

    1990-01-01

    Conventional chest radiography is the most commonly performed technique for the detection and diagnosis of lung cancer, which is the leading cause of cancer deaths in the United States. Nevertheless, a high percentage of cancer tumors are missed with this technique. One reason for errors is the overlap of tumor image with bone image in a chest radiograph. Dual-energy radiography has been suggested as the most effective method to eliminate bone contrast for better lung tumor visualization. Dual-energy radiography also provides a bone image from which benign nodules can be identified by the presence of nodule calcification. The purpose of this study is to evaluate the performance of a film-screen based dual-energy, single-exposure technique in lung nodule detection and to improve its performance by both hardware and software developments to increase the accuracy of lung cancer diagnosis. Our previous implementation of the technique resulted in small residual tissue contrast and incomplete tissue subtraction due to screen selection and x-ray beam hardening, respectively. Hardware developments, including uses of a new screen pair (Y_2O _2S/CaWO_4) and a K-edge filter (europium), were studied to improve residual tissue contrast by increasing the energy separation. As software developments, a three-dimensional interpolation algorithm and noise suppression methods were studied to achieve complete tissue subtraction and noise reduction, respectively. The results show that the Y_2O _2S/CaWO_4 performed better than LaOBr/CaWO_4; the use of K-edge filter produced more residual tissue contrast than that obtained without it; the interpolation algorithm effectively compensated for beam hardening and resulted in more complete tissue subtraction than image subtraction; and the noise suppression methods reduced noise by half. Even though the dual-exposure technique performed better than the single-exposure technique in a simulated lung nodule detection study, the difference between

  13. Facility modernization Annular Core Research Reactor

    SciTech Connect

    Morris, F.M.; Luera, T.F.; McCrory, F.M.; Nelson, D.A.; Trowbridge, F.R.; Wold, S.A.

    1990-07-01

    The Annular Core Research Reactor (ACRR) has undergone numerous modifications since its conception in response to program needs. The original reactor fuel, which was special U-ZrH TRIGA fuel designed primarily for pulsing, has been replaced with a higher pulsing capacity BeO fuel. Other advanced operating modes which use this increased capability, in addition to the pulse and steady state, have been incorporated to tailor power histories and fluences to the experiments. Various experimental facilities have been developed that range from a radiography facility to a 50 cm diameter External Fuel Ring Cavity (FREC) using 180 of the original ZrH fuel elements. Currently a digital reactor console is being produced with GA, which will give enhanced monitoring capabilities of the reactor parameters while leaving the safety-related shutdown functions with analog technology. (author)

  14. Free-focus radiography using conventional films: Radiation exposures in a simulated clinical study

    SciTech Connect

    Jensen, T.W.; Randall, G.J.; Goldberg, A.J.

    1980-07-01

    This study compared air exposures during conventional dental and maxillofacial radiography and similar views using free-focus radiography with conventional image receptors. The results show that periapical type surveys on nonscreen film placed extraorally or in the buccal fold may be carried out with an exposure to the surface tissues, which is similar to or less than conventional dental radiography. Extraoral survey type radiographs of the jaws may be carried out with significantly less surface exposure than lateral oblique views of the jaws. The least exposure was required, when the film was placed in the buccla fold instead of against the face during free-focus radiography. The exposures with film screen combinations were reduced by an order of magnitude when compared to the nonscreen techniques. Proper filtration of the beam of the miniaturized x-ray machines radiography in dentistry may thus be desirable and applications in other parts of the body encouraged.

  15. Free-focus radiography using conventional films--radiation exposures in a simulated clinical study.

    PubMed

    Jensen, T W; Randall, G J; Goldberg, A J

    1980-01-01

    This study compared air exposures during conventional dental and maxillofacial radiography and similar views using free-focus radiography with conventional image receptors. The results show that periapical type surveys on nonscreen film placed extraorally or in the buccal fold may be carried out with an exposure to the surface tissues, which is similar to or less than conventional dental radiography. Extraoral survey type radiographs of the jaws may be carried out with significantly less surface exposure than lateral oblique views of the jaws. The least exposure was required, when the film was placed in the buccla fold instead of against the face during free-focus radiography. The exposures with film screen combinations were reduced by an order of magnitude when compared to the nonscreen techniques. Proper filtration of the beam of the miniaturized x-ray machines radiography in dentistry may thus be desirable and applications in other parts of the body encouraged. PMID:7393160

  16. In situ studies of mass transport in liquid alloys by means of neutron radiography.

    PubMed

    Kargl, F; Engelhardt, M; Yang, F; Weis, H; Schmakat, P; Schillinger, B; Griesche, A; Meyer, A

    2011-06-29

    When in situ techniques became available in recent years this led to a breakthrough in accurately determining diffusion coefficients for liquid alloys. Here we discuss how neutron radiography can be used to measure chemical diffusion in a ternary AlCuAg alloy. Neutron radiography hereby gives complementary information to x-ray radiography used for measuring chemical diffusion and to quasielastic neutron scattering used mainly for determining self-diffusion. A novel Al(2)O(3) based furnace that enables one to study diffusion processes by means of neutron radiography is discussed. A chemical diffusion coefficient of Ag against Al around the eutectic composition Al(68.6)Cu(13.8)Ag(17.6) at.% was obtained. It is demonstrated that the in situ technique of neutron radiography is a powerful means to study mass transport properties in situ in binary and ternary alloys that show poor x-ray contrast. PMID:21654050

  17. Investigation of optimum X-ray beam tube voltage and filtration for chest radiography with a computed radiography system.

    PubMed

    Moore, C S; Beavis, A W; Saunderson, J R

    2008-10-01

    The purpose of this study was to determine the optimum tube voltage and amount of added copper (Cu) filtration for processed chest radiographs obtained with an Agfa 75.0 Computed Radiography (CR) system. The contrast-to-noise ratio (CNR) was measured in the lung, heart/spine and diaphragm compartments of a validated chest phantom using various tube voltages and amounts of Cu filtration. The CNR was derived as a function of air kerma at the CR plate and with the effective dose. As rib contrast can interfere with detection of nodules in chest radiography, a tissue-to-rib ratio (TRR) was derived to investigate which tube voltages suppress the contrast of rib. Although processing algorithms affect the signal and noise in a way that is hard to predict, we found that, for a given set of processing parameters, the CNR was related to the plate air kerma and effective dose in a logarithmic manner (all R(2) >or=0.97). For imaging of the lung region, a low voltage (60 kVp) produced the highest CNR, whereas a high voltage (125 kVp) produced the highest TRR. In the heart/spine region, 80-125 kVp produced the highest CNR, while in the diaphragm region 60-90 kVp produced the highest CNR. For chest radiography with this CR system, the optimal tube voltage depends upon the region of interest. Of the filters tested, a 0.1 mm Cu thickness was found to provide a statistically significant increase in the CNR in the diaphragm region with tube potentials of 60 kVp and 80 kVp, without affecting the CNR in the other anatomical compartments. PMID:18662964

  18. Investigating the use of an antiscatter grid in chest radiography for average adults with a computed radiography imaging system

    PubMed Central

    Wood, T J; Avery, G; Balcam, S; Needler, L; Smith, A; Saunderson, J R; Beavis, A W

    2015-01-01

    Objective: The aim of this study was to investigate via simulation a proposed change to clinical practice for chest radiography. The validity of using a scatter rejection grid across the diagnostic energy range (60–125 kVp), in conjunction with appropriate tube current–time product (mAs) for imaging with a computed radiography (CR) system was investigated. Methods: A digitally reconstructed radiograph algorithm was used, which was capable of simulating CR chest radiographs with various tube voltages, receptor doses and scatter rejection methods. Four experienced image evaluators graded images with a grid (n = 80) at tube voltages across the diagnostic energy range and varying detector air kermas. These were scored against corresponding images reconstructed without a grid, as per current clinical protocol. Results: For all patients, diagnostic image quality improved with the use of a grid, without the need to increase tube mAs (and therefore patient dose), irrespective of the tube voltage used. Increasing tube mAs by an amount determined by the Bucky factor made little difference to image quality. Conclusion: A virtual clinical trial has been performed with simulated chest CR images. Results indicate that the use of a grid improves diagnostic image quality for average adults, without the need to increase tube mAs, even at low tube voltages. Advances in knowledge: Validated with images containing realistic anatomical noise, it is possible to improve image quality by utilizing grids for chest radiography with CR systems without increasing patient exposure. Increasing tube mAs by an amount determined by the Bucky factor is not justified. PMID:25571914

  19. Correlation of the clinical and physical image quality in chest radiography for average adults with a computed radiography imaging system

    PubMed Central

    Wood, T J; Beavis, A W; Saunderson, J R

    2013-01-01

    Objective: The purpose of this study was to examine the correlation between the quality of visually graded patient (clinical) chest images and a quantitative assessment of chest phantom (physical) images acquired with a computed radiography (CR) imaging system. Methods: The results of a previously published study, in which four experienced image evaluators graded computer-simulated postero-anterior chest images using a visual grading analysis scoring (VGAS) scheme, were used for the clinical image quality measurement. Contrast-to-noise ratio (CNR) and effective dose efficiency (eDE) were used as physical image quality metrics measured in a uniform chest phantom. Although optimal values of these physical metrics for chest radiography were not derived in this work, their correlation with VGAS in images acquired without an antiscatter grid across the diagnostic range of X-ray tube voltages was determined using Pearson’s correlation coefficient. Results: Clinical and physical image quality metrics increased with decreasing tube voltage. Statistically significant correlations between VGAS and CNR (R=0.87, p<0.033) and eDE (R=0.77, p<0.008) were observed. Conclusion: Medical physics experts may use the physical image quality metrics described here in quality assurance programmes and optimisation studies with a degree of confidence that they reflect the clinical image quality in chest CR images acquired without an antiscatter grid. Advances in knowledge: A statistically significant correlation has been found between the clinical and physical image quality in CR chest imaging. The results support the value of using CNR and eDE in the evaluation of quality in clinical thorax radiography. PMID:23568362

  20. Accuracy of direct digital radiography for detecting occlusal caries in primary teeth compared with conventional radiography and visual inspection: an in vitro study

    PubMed Central

    Dias da Silva, P R; Martins Marques, M; Steagall, W; Medeiros Mendes, F; Lascala, C A

    2010-01-01

    Objectives The diagnosis of caries lesions is still a matter of concern in dentistry. The diagnosis of dental caries by digital radiography has a number of advantages over conventional radiography; however, this method has not been explored fully in the field of paediatric dentistry. This in vitro research evaluated the accuracy of direct digital radiography compared with visual inspection and conventional radiography in the diagnosis of occlusal caries lesions in primary molars. Methods 50 molars were selected and evaluated under standardized conditions by 2 previously calibrated examiners according to 3 diagnostic methods (visual inspection, conventional radiography and direct digital radiography). Direct digital radiographs were obtained with the Dixi3 system (Planmeca, Helsinki, Finland) and the conventional radiographs with InSight film (Kodak Eastman Co., Rochester, NY). The images were scored and a reference standard was obtained histologically. The interexaminer reliability was calculated using Cohen's kappa test and the specificity, sensitivity and accuracy of the methods were calculated. Results Examiner reliability was good. For lesions limited to the enamel, visual inspection showed significantly higher sensitivity and accuracy than both radiographic methods, but no significant difference was found in specificity. For teeth with dentinal caries, no significant differences were found for any parameter when comparing visual and radiographic evaluation. Conclusions Although less accurate than the visual method for detecting caries lesions confined to the enamel, the direct digital radiographic method is as effective as conventional radiographic examination and visual inspection of primary teeth with occlusal caries when the dentine is involved. PMID:20729186

  1. Design and operation of a proton microscope for radiography at 800 MEV

    SciTech Connect

    Mottershead, C. T.; Barlow, D. B.; Blind, B.; Hogan, G. E.; Jason, A. J.; Merrill, F. E.; Morley, Kevin B.; Morris, C.; Saunders, A.; Valdiviez, R.

    2003-01-01

    A high-magnification high-resolution option is desirable for the study of small-scale dynamic experiments at the LANSCE 800-MeV Proton Radiography Facility. Magnification is achievable by either repowering the existing imaging-lens quadrupoles, using new high-gradient quadrupoles, or some hybrid combination of the two. The large and complex parameter space of magnetic optics solutions was studied extensively with the 3rd order optics code MARYLIE. Some of the hybrid solutions achieve magnifications up to 150, but at the price of high chromatic aberrations. In the end, a design using only new high-gradient permanent-magnet quadrupoles was selected and built at the design parameters that minimized chromatic aberration per unit magnification. The design has a moderate magnification of 7.1 and 15.8 at the two existing image stations. First-beam commissioning results exceeded expectations. Image contrast is produced by multiple Coulomb scattering in the thin objects. Early experimental objectives are to optimize this contrast by collimator design and by adjusting the correlation in the illuminating beam, as well as to characterize the (quite high) resolution limits of the system.

  2. Los Alamos National Laboratory`s Mobile Real Time Radiography System

    SciTech Connect

    Vigil, J.; Taggart, D.; Betts, S.; Mendez, J.; Rael, C.; Martinez, F.

    1997-01-01

    A 450-KeV Mobile Real Time Radiography (RTR) System was delivered to Los Alamos National Laboratory (LANL) in January 1996. It was purchased to inspect containers of radioactive waste produced at (LANL). Since its delivery it has been used to radiograph greater than 600 drums of radioactive waste at various LANL sites. It has the capability of inspecting waste containers of various sizes. It has three independent X-Ray acquisition formats. The primary system used is a 12 in. image intensifier, the second is a 36 in. linear diode array (LDA) and the last is an open system. It is fully self contained with on board generator, HVAC and a fire suppression system. It is on a 53 ft long X 8 ft. wide X 14 ft. high trailer that can be moved over any highway requiring only a easily obtainable overweight permit because it weighs approximately 38 tons. It was built to conform to industry standards for a cabinet system which does not require an exclusion zone. The fact that this unit is mobile has allowed us to operate where the waste is stored, rather than having to move the waste to a fixed facility.

  3. Pulsed-Power Driven Liner-On-Target Hydrodynamics Experiments Diagnosed with Proton Radiography using PHELIX

    NASA Astrophysics Data System (ADS)

    Oro, D. M.; Rousculp, C. L.; Reass, W. A.; Griego, J. R.; Turchi, P. J.; Reinovsky, R. E.; Saunders, A.; Mariam, F. G.; Morris, C.

    2015-06-01

    The Precision High Energy-density Liner Implosion eXperiment, PHELIX, is a pulsed-power driver capable of delivering multi-mega-ampere currents to cylindrical loads. The pulsed-power system utilizes a high-efficiency transformer to couple a small capacitor bank (~400 kJ) to a ~5 cm diameter cylindrical Al liner. A peak current of ~4 MA causes the liner to implode in 20 - 30 μs and attain speeds of >1 km/s. The PHELIX system is designed to be compatible with the Los Alamos proton radiography facility. Initial experiments with PHELIX explore shocked-ejected particle transport into gas in converging geometries. For these experiments a liner-on-target configuration is employed. To control the initial conditions, micron-sized tungsten particles are used in place of shock-formed ejecta. The inner surface of the cylindrical target is coated with a 0.1 mm uniform layer of W powder. The liner impacts the target generating a shock that launches the W particles off the target surface. The time history of the trajectory of the shocked-ejected particulate is captured in 21 proton radiographs recorded during the experiment. Comparison of 3 experiments, one into vacuum, one into Ar at 8.3 bars and one into Xe at 8.3 bars are discussed. Results are compared to simulations. Work supported by United States-DOE under contract DE-AC52-06NA25396.

  4. Ultra-high speed burst-mode imager for multi-frame radiography

    SciTech Connect

    Kwiatkowski, Kris; Nedrow, Paul; Mariam, Fesseha; Merrill, Frank E; Morris, Chris L; Saunders, Abdy; Hogan, Gary; Douance, Vincent; Bal, Yibin; Joshi, Atul; Auyeung, John

    2010-01-01

    A 720 x 720 pixel hybrid-CMOS imager was fabricated by Rockwell Scientific (now Teledyne Imaging Sensors). Several cameras have been in operation for 5 years, in a variety of static and dynamic experiments, at the 800MeV proton radiography (pRAD) facility at the LANSCE accelerator. The cameras can operate with a per-pulse adjustable inter-frame time of 250ns to 2s, and with an exposure/integration-time as short as 150 ns. Given the 800 ms total readout time, the imager can be externally synchronized to 0.1-to-5Hz, 50-ns wide proton beam pulses, and record 1000-frame radiographic movies of 5-to-30 minute duration. The effectiveness and dependence of the global electronic shutter on the pixelated Si photo-sensor bias voltage is discussed. The spatial resolution dependence of the full imaging system on various monolithic and structured scintillators is presented. We also present features of a new-generation 10-frame, 1024 x 1024 pixel, 50-ns exposure, 12-bit dynamic range imager, which is now in the design phase.

  5. Effects of electron beam dynamics on resolution of X-ray radiography

    NASA Astrophysics Data System (ADS)

    Christenson, P. J.; Kwan, T. J. T.

    2000-10-01

    In this study we link particle in cell (PIC) calculations from the code, MERLIN, with electron-photon Monte Carlo calculations using the code, MCNP, to produce synthetic radiographs. The results are used to examine several factors that may have an effect on the resolution of dynamic x-ray radiography such as done at the DARHT (Dual Axis Radiographic Hydro-Test) facility. Three properties are varied in this study, and the results of those variations are examined. First, the electron beam rise time from the accelerator is altered, and the difference on the temporal x-ray production is examined as well as the overall effects on the resolution of the radiographic image. Next, the effects of thermal velocity and energy spread of the electron beam as it exits the accelerator are studied by varying from a cold beam to a more realistic beam that fits with the expected or measured DARHT beam parameters. Finally, the bremsstrahlung conversion target composition is varied, and the effects of target materials and configurations are examined.

  6. Time-resolved Fast Neutron Radiography of Air-water Two-phase Flows

    NASA Astrophysics Data System (ADS)

    Zboray, Robert; Dangendorf, Volker; Mor, Ilan; Tittelmeier, Kai; Bromberger, Benjamin; Prasser, Horst-Michael

    Neutron imaging, in general, is a useful technique for visualizing low-Z materials (such as water or plastics) obscured by high-Z materials. However, when significant amounts of both materials are present and full-bodied samples have to be examined, cold and thermal neutrons rapidly reach their applicability limit as the samples become opaque. In such cases one can benefit from the high penetrating power of fast neutrons. In this work we demonstrate the feasibility of time-resolved, fast neutron radiography of generic air-water two-phase flows in a 1.5 cm thick flow channel with Aluminum walls and rectangular cross section. The experiments have been carried out at the high-intensity, white-beam facility of the Physikalisch-Technische Bundesanstalt, Germany. Exposure times down to 3.33 ms have been achieved at reasonable image quality and acceptable motion artifacts. Different two-phase flow regimes such as bubbly slug and churn flows have been examined. Two-phase flow parameters like the volumetric gas fraction, bubble size and bubble velocities have been measured.

  7. Simultaneous unfolding of compression and opacity from time-resolved radiography

    NASA Astrophysics Data System (ADS)

    Swift, D.; Hawreliak, J.; Rothman, S.; Kritcher, A.; Doeppner, T.; Collins, G.; Gaffney, J.; Rose, S.

    2013-06-01

    Radiographs of symmetric objects can be analyzed to give the spatial variation of attenuation, as in the Abel inversion of an axisymmetric object. If the opacity is known, the mass density can be derived from the attenuation. The space- and time-variation of density is needed to make equation of state (EOS) measurements by radiography, e.g. by measuring the speed and compression of a shock. However, in our experiments using hohlraum drive at the National Ignition Facility (NIF) to perform EOS measurements at gigabar pressures with spherically-converging shocks, the opacity may vary by an order of magnitude because of ionization. We have developed a new algorithm to simultaneously deduce the compression and opacity of the sample given time-resolved radiographs with a Lagrangian location behind the shock, such as the edge of the sample. This approach relies on spatial integration to deduce the opacity in the region just behind the shock from the difference between the known and apparent mass. We assume that the change in opacity is dominated by shock-heating, so that subsequent variations, as shocked material is either released or compressed further, are negligible or can be accounted for by a model. We used this algorithm to analyze our NIF data on the Hugoniot of CH at 10-40 TPa. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  8. X-ray energy flow and radiography measurements of evolving density perturbations

    NASA Astrophysics Data System (ADS)

    Moore, A. S.; Graham, P.; Taylor, M. J.; Foster, J. M.; Sorce, C.; Reighard, A.; MacLaren, S.; Young, P.; Glendinning, G.; Blue, B. E.; Back, C. A.; Hund, J.

    2008-11-01

    X-radiation transport through plasma density gradients, such as N-waves, form a closely coupled system that is challenging to simulate. Such situations are a key component of the physics of laser-heated hohlraums occurring in the laser-heated cavity and also in the laser-entry and any diagnostic holes. In addition the similarity to some astrophysical conditions may mean that such experiments can be used as a laboratory-scale analogue for their investigation. To better understand these phenomena, we present results from a series of experiments performed at the Omega laser facility. Using a laser-heated hohlraum drive, a tantalum aerogel with an initial seed perturbation is heated, and x-rays initially free-stream through the perturbation before they fill with plasma and radiation transport becomes diffuse. We present energy flux measurements diagnosed using two different methods, and complementary radiography results that achieve sufficient contrast, despite the high background of the hohlraum, to enable the complex shock interactions and stagnation to be directly observed. These results are compared with simulations performed using a 2-D Eulerian hydrocode, which are able to reproduce the overall energetics, and much of the details of the deceleration shock and axial stagnation region at the centre of the slit.

  9. The need for skull radiography in patients presenting for CT

    SciTech Connect

    Tress, B.M.

    1983-01-01

    One thousand patients had both CT of the head and a conventional skull series of radiographs. Radiographic findings were abnormal in 250 patients (25%), but only 64 patients (6.4%) had diagnostically significant abnormalities at radiography that were not detected by CT. If the 163 patients who presented after acute trauma were excluded from the series, only 39 (4.7%) of the remaining patients had radiographically significant abnormal findings that were not seen at CT, and only two (0.2%) of these abnormalities could not be diagnosed by a lateral skull radiograph alone. In only five patients (0.5%) was the management actively changed because an abnormaltiy that was detected at skull radiography was not detected at CT. Thus, in nontrauma patients who have stroke, epilepsy, dementia, or non-specific symptoms without focal signs, or have recently undergone craniotomy, and who have been referred for CT, skull radiographs are not justified. In the patient with a history and findings that are strongly suggestive of a pathological disorder anywhere other than in the sella turcica, cerebello-pontine angle, and paranasal sinuses, only the lateral skull radiograph should be obtained after CT, and only if CT is equivocal.

  10. Dose measurements in intraoral radiography using thermoluminescent dosimeters

    NASA Astrophysics Data System (ADS)

    Azorín, C.; Azorín, J.; Aguirre, F.; Rivera, T.

    2015-01-01

    The use of X-ray in medicine demands to expose the patient and the professional to the lowest radiation doses available in agreement with ALARA philosophy. The reference level for intraoral dental radiography is 7 mGy and, in Mexico, a number of examinations of this type are performed annually. It is considered that approximately 25% of all the X-rays examinations carried out in our country correspond to intraoral radiographies. In other hand, most of the intraoral X-ray equipment correspond to conventional radiological systems using film, which are developed as much manual as automatically. In this work the results of determining the doses received by the patients in intraoral radiological examinations made with different radiological systems using LiF:Mg,Cu,P+PTFE thermoluminescent dosimeters are presented. In some conventional radiological systems using film, when films are developed manual or automatically, incident kerma up to 10.61 ± 0.74 mGv were determined. These values exceed that reference level suggested by the IAEA and in the Mexican standards for intraoral examinations.

  11. Evaluation of image quality in computed radiography based mammography systems

    NASA Astrophysics Data System (ADS)

    Singh, Abhinav; Bhwaria, Vipin; Valentino, Daniel J.

    2011-03-01

    Mammography is the most widely accepted procedure for the early detection of breast cancer and Computed Radiography (CR) is a cost-effective technology for digital mammography. We have demonstrated that CR mammography image quality is viable for Digital Mammography. The image quality of mammograms acquired using Computed Radiography technology was evaluated using the Modulation Transfer Function (MTF), Noise Power Spectrum (NPS) and Detective Quantum Efficiency (DQE). The measurements were made using a 28 kVp beam (RQA M-II) using 2 mm of Al as a filter and a target/filter combination of Mo/Mo. The acquired image bit depth was 16 bits and the pixel pitch for scanning was 50 microns. A Step-Wedge phantom (to measure the Contrast-to-noise ratio (CNR)) and the CDMAM 3.4 Contrast Detail phantom were also used to assess the image quality. The CNR values were observed at varying thickness of PMMA. The CDMAM 3.4 phantom results were plotted and compared to the EUREF acceptable and achievable values. The effect on image quality was measured using the physics metrics. A lower DQE was observed even with a higher MTF. This could be possibly due to a higher noise component present due to the way the scanner was configured. The CDMAM phantom scores demonstrated a contrast-detail comparable to the EUREF values. A cost-effective CR machine was optimized for high-resolution and high-contrast imaging.

  12. Building a cost efficient digital radiography system for educational purposes

    NASA Astrophysics Data System (ADS)

    Brown, Chris

    Due to the growing need for Medical Physicists, many universities are implementing a Medical Physics program into their academic catalog. To help establish a new program, feasible equipment may be needed to help academic departments provide a hands-on experience for students and help teach the basic concepts of Medical Physics. For example, clinical Digital Radiography Systems (DRS) are used to help teach the basic concepts of digital imaging. However, such systems can cost in excess of 100,000, creating a financial obstacle that will be difficult to overcome. Hence, the development of a cost efficient digital radiography system may be desired in order to eliminate the financial obstacle and give students a hands-on learning experience. This DRS uses three main components to develop an image, an x-ray source, an intensifying plate, and a charge-coupled device (CCD) camera. All three components are housed in a lead-lined box. The purpose of this project is to find the limitations of our DRS and compare the price between our DRS and commercially available DRSs. At optimal settings, a SNR of 25 is shown across the intensifying screen that can identify objects as small as 0.42mm. A Contrast-detail phantom shows the ability to decipher the varying thickness of foam rubber squares. The total cost of our DRS comes to 17,000.00, a fractional price tag compared to a commercially available DRS.

  13. A note on digital dental radiography in forensic odontology

    PubMed Central

    Chiam, Sher-Lin

    2014-01-01

    Digital dental radiography, intraoral and extraoral, is becoming more popular in dental practice. It offers convenience, such as lower exposure to radiation, ease of storing of images, and elimination of chemical processing. However, it also has disadvantages and drawbacks. One of these is the potential for confusion of the orientation of the image. This paper outlines one example of this, namely, the lateral inversion of the image. This source of confusion is partly inherent in the older model of phosphor storage plates (PSPs), as they allow both sides to be exposed without clue to the fact that the image is acquired on the wrong side. The native software allows digital manipulation of the X-ray image, permitting both rotation and inversion. Attempts to orientate the X-ray according to the indicator incorporated on the plate can then sometimes lead to inadvertent lateral inversion of the image. This article discusses the implications of such mistakes in dental digital radiography to forensic odontology and general dental practice. PMID:25177144

  14. Using Digital Radiography To Image Liquid Nitrogen in Voids

    NASA Technical Reports Server (NTRS)

    Cox, Dwight; Blevins, Elana

    2007-01-01

    Digital radiography by use of (1) a field-portable x-ray tube that emits low-energy x rays and (2) an electronic imaging x-ray detector has been found to be an effective technique for detecting liquid nitrogen inside voids in thermal-insulation panels. The technique was conceived as a means of investigating cryopumping (including cryoingestion) as a potential cause of loss of thermal insulation foam from space-shuttle external fuel tanks. The technique could just as well be used to investigate cryopumping and cryoingestion in other settings. In images formed by use of low-energy x-rays, one can clearly distinguish between voids filled with liquid nitrogen and those filled with gaseous nitrogen or other gases. Conventional film radiography is of some value, but yields only non-real-time still images that do not show time dependences of levels of liquids in voids. In contrast, the present digital radiographic technique yields a succession of images in real time at a rate of about 10 frames per second. The digitized images can be saved for subsequent analysis to extract data on time dependencies of levels of liquids and, hence, of flow paths and rates of filling and draining. The succession of images also amounts to a real-time motion picture that can be used as a guide to adjustment of test conditions.

  15. Intense X-ray machine for penetrating radiography

    NASA Astrophysics Data System (ADS)

    Lucht, Roy A.; Eckhouse, Shimon

    Penetrating radiography has been used for many years in the nuclear weapons research programs. Infrequently penetrating radiography has been used in conventional weapons research programs. For example the Los Alamos PHERMEX machine was used to view uranium rods penetrating steel for the GAU-8 program, and the Ector machine was used to see low density regions in forming metal jets. The armor/anti-armor program at Los Alamos has created a need for an intense flash X-ray machine that can be dedicated to conventional weapons research. The Balanced Technology Initiative, through DARPA, has funded the design and construction of such a machine at Los Alamos. It will be an 8- to 10-MeV diode machine capable of delivering a dose of 500 R at 1 m with a spot size of less than 5 mm. The machine used an 87.5-stage low inductance Marx generator that charges up a 7.4-(Omega), 32-ns water line. The water line is discharged through a self-breakdown oil switch into a 12.4-(Omega) water line that rings up the voltage into the high impendance X-ray diode. A long (233-cm) vacuum drift tube is used to separate the large diameter oil-insulated diode region from the X-ray source area that may be exposed to high overpressures by the explosive experiments. The electron beam is selffocused at the target area using a low pressure background gas.

  16. Assessing The Impact Of Computed Radiography And PACS

    NASA Astrophysics Data System (ADS)

    Hedgcock, Marcus W.; Kehr, Katherine

    1989-05-01

    Our institution (San Francisco VA Medical Center) is a VA pilot center for total digital imaging and PACS. Quantitative information about PACS impact on health care is limited, because no centers have done rigorous preimplementation studies. We are gathering quantitative service delivery and cost data before, during, and after stepwise implementation of computed radiography and PACS at our institution to define the impact on imaging service delivery. We designed a simple audit method using the x-ray request and time clocks to determine patient waiting time, imaging time, film use, image availability to the radiologist, matching of current with previous images, image availability to clinicians, and time to final interpretation. Our department model is a multichannel, mulitserver patient queue. Our current radiograph file is space limited, containing only one year of images; older images are kept in a remote file area in another building. In addition, there are 16 subfile areas within the Radiology Service and the medical center. Our preimplementation audit showed some long waiting times (40 minutes, average 20) and immediate retrieval of prior films in only 42% of cases, with an average retrieval time of 22 hours. Computed radiography and the optical archive have the potential to improve these figures. The audit will be ongoing and automated as implementation of PACS progresses, to measure service improvement and learning curve with the new equipment. We present the audit format and baseline preimplementation figures.

  17. High contrast radiography of normal and cataractous canine lenses

    NASA Astrophysics Data System (ADS)

    Antunes, A.; Hönnicke, M. G.; Cusatis, C.; Morelhão, S. L.

    2005-05-01

    Cataract is a disease that degrades the transparency of crystalline lenses. The crystalline lens is a cellular structure that has a unique shape and protein composition. Cataract is associated with changes in the structure and composition of the lenses. Analyser-based x-ray phase contrast imaging (PCI) is a non-destructive technique that presents images with more contrast and details than the images acquired with conventional synchrotron radiography. Here, an analyser-based x-ray PCI set-up was optimized in the XRD2 beamline at Brazilian Synchrotron Light Laboratory for comparative studies on PCI and conventional synchrotron radiography, for non-cataractous (healthy tissue) and cataractous crystalline (diseased tissue) lenses. Refraction angle and apparent absorption contrast images (diffraction enhanced imaging—DEI) were also obtained. The present PCI and DEI images indicate that the healthy tissue shows enhanced shell structures, while in the diseased tissue these are almost absent. This is associated with the clinical case of total opacity of the cataractous crystalline lenses when it is exposed to visible light.

  18. Towards optimization in digital chest radiography using Monte Carlo modelling.

    PubMed

    Ullman, Gustaf; Sandborg, Michael; Dance, David R; Hunt, Roger A; Alm Carlsson, Gudrun

    2006-06-01

    A Monte Carlo based computer model of the x-ray imaging system was used to investigate how various image quality parameters of interest in chest PA radiography and the effective dose E vary with tube voltage (90-150 kV), additional copper filtration (0-0.5 mm), anti-scatter method (grid ratios 8-16 and air gap lengths 20-40 cm) and patient thickness (20-28 cm) in a computed radiography (CR) system. Calculated quantities were normalized to a fixed value of air kerma (5.0 microGy) at the automatic exposure control chambers. Soft-tissue nodules were positioned at different locations in the anatomy and calcifications in the apical region. The signal-to-noise ratio, SNR, of the nodules and the nodule contrast relative to the contrast of bone (C/C(B)) as well as relative to the dynamic range in the image (C(rel)) were used as image quality measures. In all anatomical regions, except in the densest regions in the thickest patients, the air gap technique provides higher SNR and contrast ratios than the grid technique and at a lower effective dose E. Choice of tube voltage depends on whether quantum noise (SNR) or the contrast ratios are most relevant for the diagnostic task. SNR increases with decreasing tube voltage while C/C(B) increases with increasing tube voltage. PMID:16723762

  19. Toward practical 3D radiography of pipeline girth welds

    NASA Astrophysics Data System (ADS)

    Wassink, Casper; Hol, Martijn; Flikweert, Arjan; van Meer, Philip

    2015-03-01

    Digital radiography has made its way into in-the-field girth weld testing. With recent generations of detectors and x-ray tubes it is possible to reach the image quality desired in standards as well as the speed of inspection desired to be competitive with film radiography and automated ultrasonic testing. This paper will show the application of these technologies in the RTD Rayscan system. The method for achieving an image quality that complies with or even exceeds prevailing industrial standards will be presented, as well as the application on pipeline girth welds with CRA layers. A next step in development will be to also achieve a measurement of weld flaw height to allow for performing an Engineering Critical Assessment on the weld. This will allow for similar acceptance limits as currently used with Automated Ultrasonic Testing of pipeline girth welds. Although a sufficient sizing accuracy was already demonstrated and qualified in the TomoCAR system, testing in some applications is restricted to time limits. The paper will present some experiments that were performed to achieve flaw height approximation within these time limits.

  20. DETECTION OF LACK OF FUSION WELD DEFECTS BY RADIOGRAPHY

    SciTech Connect

    Souza, M. P.; Almeida, R. M.; Rebello, J. M. A.

    2009-03-03

    In this work, radiography was employed as the NDT technique for detection of flaws in circumferential girth welds of steel pipelines used in offshore installations in the petroleum industry. The kind of defect specifically focused was lack of fusion. It is currently accepted in the literature that radiography is not as sensitive as ultrasonics to detect lack of fusion defects. Unfortunately, the radiographic inspection can barely detect lack of fusion and only when it is associated to inclusions and voids of considerable size. However, in a previous article ('Reliability of radiographic inspection of steel pipeline girth welds', QNDE Conference, 2007), the authors showed that it is possible to detect lack of fusion defects if, in the radiographic tests, the angle of incidence is the same angle that the weld bevel makes with the test piece surface, which means lowering the angle of disorientation between the flaw and the radiographic beam. However, no concerns were made to sizing the defects. Computational simulation was used with XRSIM software to establish the optimal radiographic parameters to reach the lower limit for detection for this kind of defect.

  1. Toward practical 3D radiography of pipeline girth welds

    SciTech Connect

    Wassink, Casper

    2015-03-31

    Digital radiography has made its way into in-the-field girth weld testing. With recent generations of detectors and x-ray tubes it is possible to reach the image quality desired in standards as well as the speed of inspection desired to be competitive with film radiography and automated ultrasonic testing. This paper will show the application of these technologies in the RTD Rayscan system. The method for achieving an image quality that complies with or even exceeds prevailing industrial standards will be presented, as well as the application on pipeline girth welds with CRA layers. A next step in development will be to also achieve a measurement of weld flaw height to allow for performing an Engineering Critical Assessment on the weld. This will allow for similar acceptance limits as currently used with Automated Ultrasonic Testing of pipeline girth welds. Although a sufficient sizing accuracy was already demonstrated and qualified in the TomoCAR system, testing in some applications is restricted to time limits. The paper will present some experiments that were performed to achieve flaw height approximation within these time limits.

  2. Development of a Logging Tool for Muon Radiography

    NASA Astrophysics Data System (ADS)

    Suenaga, H.; Kiho, K.; Miyakawa, K.; Tanaka, H.

    2012-04-01

    A research for high level radioactive waste disposal should investigate geological structure and saturation change of rock mass around a disposal cavern. In the CO2 geological storage and the underground storage of crude oil, natural gas or liquefied petroleum gas (LPG), it is necessary to monitor an upward migration of a gaseous fluid which is stored in underground. For an investigation of slope stability, it is effective to evaluate a high saturation area in the ground's pore space as the area should be the same as that of a rainfall infiltration. Since these phenomena could be evaluated by a measurement of a density variation in underground rock, an application of muon radiography is highly prospective. The Central Research Institute of Electric Power Industry (CRIEPI) has a plan to conduct a field experiment to evaluate an applicability of the muon radiography to engineering geology in cooperation with Electric Power Development Co., Ltd. (J-POWER). The field experiment will be performed this year in slope topography. If the applicability will be revealed as a result of the field experiment, CRIEPI will start a research on development of a logging tool which can measure muon in a borehole. We plan to build a prototype of the logging tool in around three years and will put it into practical use in around five years.

  3. Multiple-Image Radiography for Human Soft Tissue

    SciTech Connect

    Muehleman,C.; Li, J.; Zhong, Z.; Brankov, J.; Wernick, M.

    2006-01-01

    Conventional radiography only provides a measure of the X-ray attenuation caused by an object; thus, it is insensitive to other inherent informative effects, such as refraction. Furthermore, conventional radiographs are degraded by X-ray scatter that can obscure important details of the object being imaged. The novel X-ray technology diffraction-enhanced imaging (DEI) has recently allowed the visualization of nearly scatter-free images displaying both attenuation and refraction properties. A new method termed multiple-image radiography (MIR) is a significant improvement over DEI, corrects errors in DEI, is more robust to noise and produces an additional image that is entirely new to medical imaging. This new image, which portrays ultra-small-angle X-ray scattering (USAXS) conveys the presence of microstructure in the object, thus differentiating homogeneous tissues from tissues that are irregular on a scale of micrometers. The aim of this study was to examine the use of MIR for evaluation of soft tissue, and in particular to conduct a preliminary investigation of the USAXS image, which has not previously been used in tissue imaging.

  4. Quantitative assessment of computed radiography quality control parameters.

    PubMed

    Rampado, O; Isoardi, P; Ropolo, R

    2006-03-21

    Quality controls for testing the performance of computed radiography (CR) systems have been recommended by manufacturers and medical physicists' organizations. The purpose of this work was to develop a set of image processing tools for quantitative assessment of computed radiography quality control parameters. Automatic image analysis consisted in detecting phantom details, defining regions of interest and acquiring measurements. The tested performance characteristics included dark noise, uniformity, exposure calibration, linearity, low-contrast and spatial resolution, spatial accuracy, laser beam function and erasure thoroughness. CR devices from two major manufacturers were evaluated. We investigated several approaches to quantify the detector response uniformity. We developed methods to characterize the spatial accuracy and resolution properties across the entire image area, based on the Fourier analysis of the image of a fine wire mesh. The implemented methods were sensitive to local blurring and allowed us to detect a local distortion of 4% or greater in any part of an imaging plate. The obtained results showed that the developed image processing tools allow us to implement a quality control program for CR with short processing time and with absence of subjectivity in the evaluation of the parameters. PMID:16510964

  5. Health Facilities

    MedlinePlus

    Health facilities are places that provide health care. They include hospitals, clinics, outpatient care centers, and specialized care centers, such as birthing centers and psychiatric care centers. When you ...

  6. Facility Planning.

    ERIC Educational Resources Information Center

    Graves, Ben E.

    1984-01-01

    This article reviews recommendations on policies for leasing surplus school space made during the Council of Educational Facility Planners/International conference. A case study presentation of a Seattle district's use of lease agreements is summarized. (MJL)

  7. Production facilities

    SciTech Connect

    Not Available

    1989-01-01

    This book presents a cross section of different solutions to the many unique production problems operators face. Sections address benefit vs. cost options for production facility designs, oil and gas separation processes and equipment, oil treating and desalting systems, and water treating methods and equipment. Papers were selected to give an overall view of factors involved in optimizing the design of cost-effective production facilities.

  8. High-ratio grid considerations in mobile chest radiography

    SciTech Connect

    Scott, Alexander W.; Gauntt, David M.; Yester, Michael V.; Barnes, Gary T.

    2012-06-15

    Purpose: Grids are often not used in mobile chest radiography, and when used, they have a low ratio and are often inaccurately aligned. Recently, a mobile radiography automatic grid alignment system (MRAGA) was developed that accurately and automatically aligns the focal spot with the grid. The objective of this study is to investigate high-ratio grid tradeoffs in mobile chest radiography at fixed patient dose when the focal spot lies on the focal axis of the grid. Methods: The chest phantoms (medium and large) used in this study were modifications of the ANSI (American National Standards Institute) chest phantom and consisted of layers of Lucite Trade-Mark-Sign , aluminum, and air. For the large chest phantom, the amount of Lucite and aluminum was increased by 50% over the medium phantom. Further modifications included a mediastinum insert and the addition of contrast targets in the lung and mediastinum regions. Five high-ratio grids were evaluated and compared to the nongrid results at x-ray tube potentials of 80, 90, 100, and 110 kVp for both phantoms. The grids investigated were from two manufacturers: 12:1 and 15:1 aluminum interspace grids from one and 10:1, 13:1, and 15:1 fiber interspace grids from another. MRAGA was employed to align the focal spot with the grid. All exposures for a given kVp and phantom size were made using the same current-time product (CTP). The phantom images were acquired using computed radiography, and contrast-to-noise ratios (CNR) and CNR improvement factors (k{sub CNR}) were determined from the resultant images. The noise in the targets and the contrast between the targets and their backgrounds were calculated using a local detrending correction, and the CNR was calculated as the ratio of the target contrast to the background noise. k{sub CNR} was defined as the ratio of the CNR imaged with the grid divided by the CNR imaged without a grid. Results: The CNR values obtained with a high-ratio grid were 4%-65% higher than those

  9. Is radiography justified for the evaluation of patients presenting with cervical spine trauma?

    SciTech Connect

    Theocharopoulos, Nicholas; Chatzakis, Georgios; Damilakis, John

    2009-10-15

    Conventional radiography has been for decades the standard method of evaluation for cervical spine trauma patients. However, currently available helical multidetector CT scanners allow multiplanar reconstruction of images, leading to increased diagnostic accuracy. The purpose of this study was to determine the relative benefit/risk ratio between cervical spine CT and cervical spine radiography and between cervical spine CT and cervical spine radiography, followed by CT as an adjunct for positive findings. A decision analysis model for the determination of the optimum imaging technique was developed. The sensitivity and specificity of CT and radiography were obtained by dedicated meta-analysis. Lifetime attributable risk of mortal cancer from CT and radiography was calculated using updated organ-specific risk coefficients and organ-absorbed doses. Patient organ doses from radiography were calculated using Monte Carlo techniques, simulated exposures performed on an anthropomorphic phantom, and thermoluminescence dosimetry. A prospective patient study was performed regarding helical CT scans of the cervical spine. Patient doses were calculated based on the dose-length-product values and Monte Carlo-based CT dosimetry software program. Three groups of patient risk for cervical spine fracture were incorporated in the decision model on the basis of hypothetical trauma mechanism and clinical findings. Radiation effects were assessed separately for males and females for four age groups (20, 40, 60, and 80 yr old). Effective dose from radiography amounts to 0.050 mSv and from a typical CT scan to 3.8 mSv. The use of CT in a hypothetical cohort of 10{sup 6} patients prevents approximately 130 incidents of paralysis in the low risk group (a priori fracture probability of 0.5%), 500 in the moderate risk group (a priori fracture probability of 2%), and 5100 in the high risk group (a priori fracture probability of 20%). The expense of this CT-based prevention is 15-32 additional

  10. Sandia National Laboratories shock thermodynamics applied research (STAR) facility

    SciTech Connect

    Asay, J.R.

    1981-08-01

    The Sandia National Laboratories Shock Thermodynamics Applied Research (STAR) Facility has recently consolidated three different guns and a variety of instrumentation capabilities into a single location. The guns available at the facility consist of a single-stage light gas gun, a single-stage propellant gun and a two-stage light gas gun, which cover a velocity range from 15 m/s to 8 km/s. Instrumentation available at the facility includes optical and microwave interferometry, time-resolved holography, fast x-radiography, framing and streak photography, fast multi-wavelength pyrometry, piezoelectric and piezoresistive gauges and computer data reduction. This report discusses the guns and instrumentation available at the facility and selected recent applications.

  11. New detector for use in fast neutron radiography

    SciTech Connect

    Popov, V.; Degtiarenko, P.; Musatov, I.

    2011-01-01

    We have developed and tested a new type detector for use in the fast neutron (FN) imaging radiography applications. FN radiography is generally used for nondestructive material testing, medical and biology applications, border patrol, transportation and cargo screening tasks. It is complementary to other types of radiography, providing additional information on light element content of the material samples. Distinct from other FN imagers presently known, our device implements a neutron-sensitive scintillator attached to a position-sensitive photomultiplier tube (PSPMT), and operates in an event-by-event readout mode, acquiring energy, timing, and pulse shape information for all detected radiation events. The information is used to help separate events of FN interactions in the scintillator from the background events caused by the electronics noise and by the other types of background radiation. Selection of pure fast neutron events in the final image allows us to achieve ultimate image contrast and resolution, as compared with other types of FN imaging devices operating most commonly in an integration mode, in which the detector's dark noise and radiation background dilute the images. The detector performance for FN imaging application was tested using D-D neutron generator, designed and manufactured by Adelphi Technology, Inc. This essentially point-like neutron source operates in continuous mode producing up to 109 of 2.5 MeV neutrons per second. Samples made of metals plastic and other material were used to measure the detector resolution, efficiency and uniformity. Results of these tests are presented and discussed. Fig. 1 shows one of the test FN radiographic images obtained using the sample made of 11 styrene plastic strips. All strips are squares 4.8 x 4.8 mm2 with six different lengths 10 to 60 mm with 10 mm increment. [A] [B] [C] Fig. 1. [A]-layout of the test sample; [B]-raw FN shadow image of the sample; [C]-map of the plastic strips as they appear on

  12. Pulmonary evaluation of patients with osteosarcoma: roles of standard radiography, tomography, CT, scintigraphy, and tomoscintigraphy

    SciTech Connect

    Vanel, D.; Henry-Amar, M.; Lumbroso, J.; Lemalet, E.; Couanet, D.; Piekarski, J.D.; Masselot, J.; Boddaert, A.; Kalifa, C.; Le Chevalier, T.

    1984-09-01

    Sixty-one radiologic evaluations were performed on 32 patients with possible pulmonary metastases from osteosarcoma. CT scanning was performed 61 times; standard chest radiography, 58; tomography, 36; scintigraphy, 40; and tomoscintigraphy, 33. Using CT as a reference, the sensitivities of the other examinations were 57% (32% of total metastases) for standard radiography, 88% (48%) for tomography, 21% (5%) for scintigraphy, and 41% (8%) for tomoscintigraphy. Of the 193 metastases, 98 were subpleural and 95 were parenchymatous. The authors' current evaluation of patients with metastases from osteosarcoma includes chest radiography and CT; the other three examinations are performed only before surgery.

  13. Proton radiography as an electromagnetic field and density perturbation diagnostic (invited)

    SciTech Connect

    Mackinnon, A.J.; Patel, P.K.; Town, R.P.; Edwards, M.J.; Phillips, T.; Lerner, S.C.; Price, D.W.; Hicks, D.; Key, M.H.; Hatchett, S.; Wilks, S.C.; Borghesi, M.; Romagnani, L.; Kar, S.; Toncian, T.; Pretzler, G.; Willi, O.; Koenig, M.; Martinolli, E.; Lepape, S.

    2004-10-01

    Laser driven proton beams have been used to diagnose transient fields and density perturbations in laser produced plasmas. Grid deflectometry techniques have been applied to proton radiography to obtain precise measurements of proton beam angles caused by electromagnetic fields in laser produced plasmas. Application of proton radiography to laser driven implosions has demonstrated that density conditions in compressed media can be diagnosed with million electron volt protons. This data has shown that proton radiography can provide unique insight into transient electromagnetic fields in super critical density plasmas and provide a density perturbation diagnostics in compressed matter.

  14. Reduction of absorbed doses in radiography of the facial skeleton

    SciTech Connect

    Julin, P.; Kraepelien, T.

    1984-11-01

    Radiation absorbed doses from radiography of the paranasal sinuses and the facial skeleton were measured with thermoluminescent dosimeters (TLD) on a phantom head using high-sensitivity screens in an Orbix stand. The entrance doses to the skin of the head ranged from 0.31 to 2.9 mGy per exposure. The absorbed dose from a full series of sinus exposures averaged 0.33 mGy for the oral mucous membrane, 0.33 mGy for the maxillary sinus mucous membrane, 0.11 MgY for the parotid gland, 0.15 MgY for the submandibular gland, 0.61 mGy for the eye lens, and 0.75 mGy for the thyroid gland region. A leaded soft collar adapted to the thyroid region reduced the thyroid doses by more than one order of magnitude, but also reduced the image field.

  15. Panoramic dental radiography using a charge-coupled device receptor.

    PubMed

    Farman, A G; Farman, T T

    1998-08-01

    Panoramic radiography using a slit beam and film/screen receptor is standard for the emergency room evaluation of mandibular fractures and also in dentistry. This study compared the spatial resolution, area distortion factors, and the dosage considerations for a panoramic system where standard film/screen and a charge-coupled device were alternatively employed as the image receptor. Resolution and image contours were determined using a lead resolution grid positioned at selected beam projection angulations. Exposure measurements were carried out using a RANDO average man phantom and a 3 cc beryllium-windowed ionization chamber. The maximum spatial resolution with film approached 5 lp mm-1 whereas with the CCD the maximum resolution was just above 4 lp mm-1. Consequently, the image layer was reduced slightly in width when using the CCD receptor. The use of the CCD resulted in skin exposure reduction exceeding 70%. PMID:9735460

  16. Low-voltage radiography on aircraft composite doublers

    SciTech Connect

    Moore, D.G.; Murray, J.D.

    1997-11-01

    Composite doublers are gaining popularity for their ability to repair and reinforce commercial aircraft structures and it is anticipated that the potential cost savings may spur wider use of this technology. But before composite doublers can be accepted by the civil aviation industry, inspection techniques must be developed to verify the integrity of the doubler and the parent material under the doubler. The Federal Aviation Administration Airworthiness Assurance NDI Validation Center (AANC) is currently developing test methods to inspect aircraft structures under composite doublers using low kilovoltage radiography. This paper documents the radiographic techniques developed by the AANC which have been found to give the best contrast of the radiographic image with reduced image distortion.

  17. Proton Radiography With Timepix Based Time Projection Chambers.

    PubMed

    Biegun, Aleksandra K; Visser, Jan; Klaver, Tom; Ghazanfari, Nafiseh; van Goethem, Marc-Jan; Koffeman, Els; van Beuzekom, Martin; Brandenburg, Sytze

    2016-04-01

    The development of a proton radiography system to improve the imaging of patients in proton beam therapy is described. The system comprises gridpix based time projection chambers, which are based on the Timepix chip designed by the Medipix collaboration, for tracking the protons. This type of detector was chosen to have minimal impact on the actual determination of the proton tracks by the tracking detectors. To determine the residual energy of the protons, a BaF 2 crystal with a photomultiplier tube is used. We present data taken in a feasibility experiment with phantoms that represent tissue equivalent materials found in the human body. The obtained experimental results show a good agreement with the performed simulations. PMID:26701179

  18. Inspection of an artificial heart by the neutron radiography technique

    NASA Astrophysics Data System (ADS)

    Pugliesi, R.; Geraldo, L. P.; Andrade, M. L. G.; Menezes, M. O.,; Pereira, M. A. S.; Maizato, M. J. S.

    1999-11-01

    The neutron radiography technique was employed to inspect an artificial heart prototype which is being developed to provide blood circulation for patients expecting heart transplant surgery. The radiographs have been obtained by the direct method with a gadolinium converter screen along with the double coated Kodak-AA emulsion film. The artificial heart consists of a flexible plastic membrane located inside a welded metallic cavity, which is employed for blood pumping purposes. The main objective of the present inspection was to identify possible damages in this plastic membrane, produced during the welding process of the metallic cavity. The obtained radiographs were digitized as well as analysed in a PC and the improved images clearly identify several damages in the plastic membrane, suggesting changes in the welding process.

  19. Contrast matching techniques for digital subtraction radiography: an objective evaluation.

    PubMed Central

    Likar, B.; Bernard, R.; Pernus, F.

    1996-01-01

    Digital subtraction radiography (DSR) enables the detection of subtle early detrimental effects of periodontal disease as well as the evaluation of the effects of therapy. However, the differences between two radiographs due to alignment and contrast errors must be kept at minimum. In the present in vitro study we test the efficacy of three basic contrast correction methods in the reduction of contrast mismatches which can adversely affect a subtracted image. The ODTF (Optical Density Thickness Function) method, which is based on a function relating grey level values of the aluminium wedge image and the corresponding thickness of the wedge, induced less contrast correction error than the CDF (Cumulative Density Function) and the LSQA (Least Square Quadratic Approximation) methods. Moreover, CDF, ODTF, and LSQA functions obtained from the reference structure density distribution may be applied for objective contrast enhancements and for standardisation of image quality, while the ODTF function allows also bone change volume estimations. PMID:8947675

  20. Measurement Of Gas Bubbles In Mercury Using Proton Radiography

    SciTech Connect

    Riemer, Bernie; Bingham, Philip R; Mariam, Fesseha G; Merrill, Frank E

    2007-01-01

    An experiment using proton radiography on a small mercury loop for testing gas bubble injection was conducted at the Los Alamos Neutron Science Center (LANSCE) in December 2006. Small gas bubble injection is one of the approaches under development to reduce cavitation damage in the U.S. Spallation Neutron Source mercury target vessel. Several hundred radiograph images were obtained as the test loop was operated over range of conditions that included two jet type bubble generators, two needle type bubble generators, various mercury flow speeds and gas injection rates, and use of helium, argon and xenon. This paper will describe the analysis of the radiograph images and present the obtained bubble measurement data.

  1. Dosimetry and image quality assessment in a direct radiography system

    PubMed Central

    Oliveira, Bruno Beraldo; de Oliveira, Marcio Alves; Paixão, Lucas; Teixeira, Maria Helena Araújo; Nogueira, Maria do Socorro

    2014-01-01

    Objective To evaluate the mean glandular dose with a solid state detector and the image quality in a direct radiography system, utilizing phantoms. Materials and Methods Irradiations were performed with automatic exposure control and polymethyl methacrylate slabs with different thicknesses to calculate glandular dose values. The image quality was evaluated by means of the structures visualized on the images of the phantoms. Results Considering the uncertainty of the measurements, the mean glandular dose results are in agreement with the values provided by the equipment and with internationally adopted reference levels. Results obtained from images of the phantoms were in agreement with the reference values. Conclusion The present study contributes to verify the equipment conformity as regards dose values and image quality. PMID:25741119

  2. [Evaluation of radiation risk associated with endodontic radiography].

    PubMed

    Danforth, R A; Torabainejad, M

    1991-01-01

    Endodontic patients are sometimes concerned about the risks of tumors or cataracts from radiation exposure during root canal therapy. By using established dose and risk information, we calculated the extent of these risks. The chance of getting leukemia from an endodontic x-ray survey using 90 kVp was found to be 1 in 7.69 million, the same as the risk of dying from cancer from smoking 0.94 cigarettes or from an auto accident when driving 3.7 km. Risk of thyroid gland neoplasia was 1 in 667,000 (smoking 11.6 cigarettes, driving 45 km) and risk of salivary gland neoplasia 1 in 1.35 million (smoking 5.4 cigarettes, driving 21.1 km). Use of 70 kVp radiography reduced these risks only slightly. To receive the threshold dose to eyes to produce cataract changes, a patient would have to undergo 10,900 endodontic surveys. PMID:1782436

  3. Personalized body segment parameters from biplanar low-dose radiography.

    PubMed

    Dumas, Raphaël; Aissaoui, Rachid; Mitton, David; Skalli, Wafa; de Guise, Jacques A

    2005-10-01

    Body segment parameters are essential data in biomechanics. They are usually computed with population-specific predictive equations from literature. Recently, medical imaging and video-based methods were also reported for personalized computation. However, these methods present limitations: some of them provide only two-dimensional measurements or external measurements, others require a lot of tomographic images for a three-dimensional (3-D) reconstruction. Therefore, an original method is proposed to compute personalized body segment parameters from biplanar radiography. Simultaneous low-dose frontal and sagittal radiographs were obtained with EOS system. The upper leg segments of eight young males and eight young females were studied. The personalized parameters computed from the biplanar radiographic 3-D reconstructions were compared to literature. The biplanar radiographic method was consistent with predictive equations based on gamma-ray scan and dual energy X-ray absorptiometry. PMID:16235661

  4. DIANE stationary neutron radiography system image quality and industrial applications

    NASA Astrophysics Data System (ADS)

    Cluzeau, S.; Huet, J.; Le Tourneur, P.

    1994-05-01

    The SODERN neutron radiography laboratory has operated since February 1993 using a sealed tube generator (GENIE 46). An experimental programme of characterization (dosimetry, spectroscopy) has confirmed the expected performances concerning: neutron flux intensity, neutron energy range, residual gamma flux. Results are given in a specific report [2]. This paper is devoted to the image performance reporting. ASTM and specific indicators have been used to test the image quality with various converters and films. The corresponding modulation transfer functions are to be determined from image processing. Some industrial applications have demonstrated the capabilities of the system: corrosion detection in aircraft parts, ammunitions filling testing, detection of polymer lacks in sandwich steel sheets, detection of moisture in a probe for geophysics, residual ceramic cores imaging in turbine blades. Various computerized electronic imaging systems will be tested to improve the industrial capabilities.

  5. A third generation mobile high energy radiography system

    SciTech Connect

    Fry, D.A.; Valdez, J.E.; Johnson, C.S.; Kimerly, H.J.; Vananne, J.R.

    1997-12-01

    A third generation mobile high energy radiographic capability has been completed and put into service by the Los Alamos National Laboratory. The system includes a 6 MeV linac x-ray generator, Co-60 gamma source, all-terrain transportation, on-board power, real-time radiography (RTR), a control center, and a complete darkroom capability. The latest version includes upgraded and enhanced portability, flexibility, all-terrain operation, all-weather operation, and ease of use features learned from experience with the first and second generation systems. All systems were required to have the following characteristics; all-terrain, all-weather operation, self-powered, USAF airlift compatible, reliable, simple to setup, easy to operate, and all components two-person portable. The systems have met these characteristics to differing degrees, as is discussed in the following section, with the latest system being the most capable.

  6. Radiation characteristics of scintillator coupled CMOS APS for radiography conditions

    NASA Astrophysics Data System (ADS)

    Kim, Kwang Hyun; Kim, Soongpyung; Kang, Dong-Won; Kim, Dong-Kie

    2006-11-01

    Under industrial radiography conditions, we analyzed short-term radiation characteristics of scintillator coupled CMOS APS (hereinafter SC CMOS APS). By means of experimentation, the contribution of the transmitted X-ray through the scintillator to the properties of the CMOS APS and the afterimage, generated in the acquired image even at low dose condition, were investigated. To see the transmitted X-ray effects on the CMOS APS, Fein focus™ X-ray machine, two scintillators of Lanex™ Fine and Regular, and two CMOS APS array of RadEye™ were used under the conditions of 50 kV p/1 mAs and 100 kV p/1 mAs. By measuring the transmitted X-ray on signal and Noise Power Spectrum, we analytically examined the generation mechanism of the afterimage, based on dark signal or dark current increase in the sensor, and explained the afterimage in the SC CMOS APS.

  7. An overview of radiography in chemical energy warhead research

    SciTech Connect

    Hull, L.M.

    1989-01-01

    The high-speed objects and the considerable light, dust, and smoke characteristic of chemical energy warhead test firing necessitate the use of flash radiography as a major diagnostic tool. This paper reviews many of the applications of radiography to chemical warhead studies conducted by many researchers at Los Alamos National Laboratory. Each type of contribution is illustrated by a figure, and the contributors are listed by figure number at the end. The emphasis of the paper is on the relationship between the kind of information obtained and the radiographic technique employed. Details of the techniques are provided only when it is necessary for clarity. A few examples of analysis of the radiographic data are given, but they are in no way exhaustive. The applications span a wide spectrum of flash x-ray energies and fluence, from 150-keV commercial machines to the 30-MeV, 120-R PHERMEX* machine. Low-energy x rays are useful; in the study of small or low-density objects such as highly disrupted penetrators, fragments, or spall. Medium-energy x rays are useful when blast and fragment protection is necessary, such as in the study of penetrator interactions with reactive armor, or if a moderate penetrating x-ray capability is required. High-energy x rays are useful when the data desired are internal to the structure and significant penetrating x-ray capability is required. This division of the techniques according to energy is rather loose. Significant overlap does exist and, therefore, each new application deserves individual consideration. 14 figs.

  8. Plasma-flash radiography utilizing a molybdenum target in dentistry

    SciTech Connect

    Yamamoto, Mariko; Takabe, Akihito; Sakamaki, Kimio

    1995-12-31

    The construction and the radiographic characteristics of a plasma flash x-ray generator having a molybdenum-target (anode tip) triode are described. This generator was primarily designed in order to perform soft radiography in dental medicine and employed the following essential components: a high-voltage power supply, a low-impedance coaxial transmission line with a gap switch, a coaxial oil condenser of 0.2 {micro}F, a turbo-molecular pump, a Krytron pulser as a trigger device, and a flash x-ray tube. The high-voltage main condenser of 0.2 {micro}F was charged from 40 to 60 kV by the power supply, and the electric charges in the condenser were discharged to the tube after closing the gap switch. Because this tube employed a long target, the plasma x-ray source which consists of molybdenum ions and electrons was easily produced by the target evaporating. The maximum tube voltage was nearly equivalent to the initial charging voltage of the main condenser, and the maximum current had a value of about 25 kA with a charging voltage of 60 kV. The average width of flash x rays was less than 1 {micro}s, and the time-integrated x-ray intensity with a charging voltage of 60 kV was approximately 20 {micro}C/kg at 1.0 m per pulse. The characteristic K-series intensity substantially increased according to increases in the charging voltage. High-speed dental radiography was performed by using a laser timing switch and a trigger-delay device.

  9. Water diffusion profile measurements in epoxy using neutron radiography

    NASA Astrophysics Data System (ADS)

    Lindsay, John T.; Matsubayashi, Masahito; Nurul Islam, Md.

    1994-12-01

    The diffusion characteristics of water in polymer materials have been studied for a few decades. Several methods have been developed to provide water diffusion characteristics as a function of time, temperature, pressure, or thickness of polymer. Unfortunately, most of these methods give the amount of water absorbed as a function of weight versus time at given environmental conditions. Concentration profiles of the water diffusion through the polymer have been unobtainable by these established methods. Neutron radiography is a method of non-destructive testing that has grown rapidly over the past ten years and is capable of giving these concentration profiles. Epoxy is one of the most commonly used polymers for which water diffusion information is important. In the automotive industry, epoxy is used both as a sealant and a bonder to prevent water from getting inside structures and causing corrosion. To prevent this corrosion, it is important to know the diffusion behavior of water in the epoxy adhesive.p ]This paper will demonstrate the use of high resolution neutron radiography as a viable method for the determination of the diffusion profile of water in commercially available epoxies. Aluminum coupons were constructed and joined together using four different epoxies. These coupons were then submerged in water. Neutron radiographs were made of the coupons as a function of total time submerged and water temperature. The weights of the coupons were also obtained as a function of submerged time for comparison with other methods. Four different epoxies were tested. Profiles of the water concentration are easily observed and measured.

  10. An experiment of muon radiography at Mt Etna (Italy)

    NASA Astrophysics Data System (ADS)

    Carbone, Daniele; Gibert, Dominique; Marteau, Jacques; Diament, Michel; Zuccarello, Luciano; Galichet, Emmanuelle

    2014-02-01

    Interactions of conduit geometry with gas-liquid flows control volcanic activity, implying that the evaluation of volcanic hazards requires quantitative understanding of the inner structure of the volcano. The more established geophysical imaging techniques suffer from inherent ambiguity, may require spatially dense measurements in active areas and may not provide sufficient spatial resolution in the uppermost part of the conduit system. It is thus desirable to develop new imaging techniques allowing a better spatial resolution of a volcano's upper feeding system, with reduced ambiguity and a low level of risk for operators. Muon particles can be utilized to image the internal density distribution of volcanic structures. The principle of muon radiography is essentially the same as X-ray radiography, except for substituting penetrating particles in place of photons. Muons are more attenuated by higher density parts inside the target and thus information about its inner structure are obtained from the differential muon absorption. We report on a muon-imaging experiment that was conducted at Mt Etna in 2010. The target structure was one of the summit craters of the volcano. This experiment was performed using a muon telescope suitably designed to withstand the harsh conditions in the summit zone of a high volcano. We found a marked difference between synthetic and observed attenuation of muons through the target. This discrepancy is likely due to the bias on the observed flux, arising from false muon tracks. They are caused by low-energy particles that, by chance, hit simultaneously the two matrixes of the telescope, leading to detection of a false positive. We separated the useful from the unwanted signal through a first-order model of the background noise. The resulting signal is compared with the corresponding synthetic flux. Eventually, we found regions of higher- and lower-than-expected muon flux, that are possibly related to inner features of the target crater.

  11. Polycapillary radiography using a quasi-x-ray-laser generator

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Hayasi, Yasuomi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Obara, Haruo; Ichimaru, Toshio; Takayama, Kazuyoshi; Ido, Hideaki; Usuki, Tatsumi; Sato, Koetsu; Tamakawa, Yoshiharu

    2001-12-01

    The characteristics of a new quasi-x-ray laser generator and its application to polycapillary radiography are described. The generator employs a high-voltage power supply, a low- impedance coaxial transmission line, a high-voltage condenser with a capacity of about 200 nF, a turbo-molecular pump, a thyristor pulse generator as a trigger device, and a new plasma flash x-ray tube. The high-voltage main condenser is charged up to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x- rays are then produced. The x-ray tube is of a demountable triode that is connected to the turbo molecular pump with a pressure of approximately 1 mPa. As the electron flows from the cathode electrode are roughly converged to the copper target by the electric field in the tube, the plasma x-ray source, which consists of metal ions and electrons, forms by the target evaporating. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increase in the charging voltage. In the present work, the peak tube voltage was almost equal to the initial charging voltage of the main condenser, and the peak current was about 25 kA with a charging voltage of 60 kV. When the charging voltage was increased, the linear plasma x-ray source formed, and the characteristic x-ray intensities of K-series lines increased. In the radiogrpahy achieved with a computed radiography system, we employed a polycapilary plate with a hole diameter of 20 micrometers and a thickness of 1 mm. The image resolution was primarily determined by the resolution of the CR system and had a value of about 100micrometers .

  12. Plasma-flash radiography utilizing a molybdenum target in dentistry

    NASA Astrophysics Data System (ADS)

    Yamamoto, Mariko; Takabe, Akihito; Sakamaki, Kimio; Sato, Eiichi; Takahashi, Kei; Sagae, Michiaki; Oizumi, Teiji; Hayasi, Yasuomi; Sasaki, Katsuaki; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1995-09-01

    The construction and the radiographic characteristics of a plasma flash x-ray generator having a molybdenum-target (anode tip) triode are described. This generator was primarily designed in order to perform soft radiography in dental medicine and employed the following essential components: a high-voltage power supply, a low-impedance coaxial transmission line with a gap switch, a coaxial oil condenser of 0.2 (mu) F, a turbo-molecular pump, a Krytron pulser as a trigger device, and a flash x-ray tube. The high-voltage main condenser of 0.2 (mu) F was charged from 40 to 60 kV by the power supply, and the electric charges in the condenser were discharged to the tube after closing the gap switch. Because this tube employed a long target, the plasma x-ray source which consists of molybdenum ions and electrons was easily produced by the target evaporating. The maximum tube voltage was nearly equivalent to the initial charge voltage of the main condenser, and the maximum current had a value of about 25 kA with a charging voltage of 60 kV. The average width of flash x rays was less than 1 microsecond(s) , and the time-integrated x-ray intensity with a charging voltage of 60 kV was approximately 20 (mu) C/kg at 1.0 m per pulse. The characteristic K-series intensity substantially increased according to increases in the charged voltage. High-speed dental radiography was performed using a laser timing switch and a trigger-delay device.

  13. Single-exposure dual-energy computed radiography.

    PubMed

    Stewart, B K; Huang, H K

    1990-01-01

    This paper focuses on analysis and development of a single-exposure dual-energy digital radiographic method using computed radiography (Fuji FCR-101 storage phosphor system). A detector sandwich consisting of storage phosphor imaging plates and an interdetector filter is used. The goal of this process is to provide a simple dual-energy method using typical plane-projection radiographic equipment and techniques. This approach exploits the transparency of the storage phosphor plates, using radiographic information that would be otherwise lost, to provide energy selective information essentially as a by-product of the radiographic examination. In order to effectively make use of the large dynamic range of the storage phosphor imaging plates (10,000:1), a computed radiography image reading mode of fixed analog-to-digital converter gain and variable photomultiplier sensitivity provides image data which can be related to relative incident exposure for export to the decomposition algorithm. Scatter rejection requirements necessitated crossed 12:1 grids for a field size of 36 x 36 cm. Optimal technique parameters obtained from computer simulation through minimization of the aluminum and Plexiglas equivalent image uncertainty under conditions of constant absorbed does resulted as: 100 kVp using a 0.15-mm-thick tin (Sn) interdetector filter for the lung field. This yields a surface exposure of 23 mR and a surface absorbed dose of 0.26 mGy for a 23-cm-thick chest. Clinical application in evaluation of the solitary pulmonary nodule is discussed, along with an image set demonstrating this application. PMID:2233574

  14. Development of a system for neutron radiography and tomography

    NASA Astrophysics Data System (ADS)

    Mühlbauer, Martin J.; Calzada, Elbio; Schillinger, Burkhard

    2005-04-01

    Neutron radiography and tomography are getting more and more popular. Since they use the white thermal neutron spectrum, they are especially feasible even at small neutron sources, where the flux is too low for efficient scattering experiments requiring monochromatization of the beam. High-end tomography systems require the investment of several ten thousand Euros, with the costs often hindering the initiative for a new tomography setup. Based on the experiences gathered at Technische Universitaet Muenchen, we developed a cheaper system based on standard components that cannot compete with the sensitivity of a high-grade system, but is perfectly capable of doing neutron radiography and tomography. The system is meant as a startup construction kit for initiating tomography programs even at small neutron sources. The system is built from scratch, enabling the user to gain an understanding for the influence of each component on the image results. With the experience thus gained, he should be able to design his next and more advanced system by himself. To keep the whole system simple and cheap (the price should reach only a few percent of a high-end system), standard parts are used whenever possible, and all components are designed in such a way that they can be built without special equipment. Public domain and freeware software is used for data processing. Such a system is being built at FRM2 in Garching within the scope of a master thesis. After completion, a website will be installed with descriptions, diagrams and software for building and operating the system. Both hardware and software are discussed.

  15. Paediatric entrance doses from exposure index in computed radiography

    NASA Astrophysics Data System (ADS)

    Vano, E.; Martinez, D.; Fernandez, J. M.; Ordiales, J. M.; Prieto, C.; Floriano, A.; Ten, J. I.

    2008-06-01

    Over the last two years we have evaluated paediatric patient doses in projection radiography derived from exposure level (EL) in computed radiography (CR) in a large university hospital. Entrance surface air kerma (ESAK) for 3501 paediatric examinations was calculated from the EL, which is a dose index parameter related to the light emitted by the phosphor-stimulable plate, archived in the Digital Imaging and Communications in Medicine (DICOM) header of the images and automatically transferred to a database using custom-built dedicated software. Typical mean thicknesses for several age bands of paediatric patients was estimated to calculate ESAK from the EL values, using results of experimental measurements with phantoms for the typical x-ray beam qualities used in paediatric examinations. Mean/median ESAK values (in µGy) for the age bands of <1 year, 1-5 years, 6-10 years and 11-15 years have been obtained for chest without a bucky: 51/41, 57/34, 91/54 and 122/109; chest with a bucky (for only the last three age bands): 114/87, 129/105 and 219/170; abdomen: 119/91, 291/225, 756/600 and 1960/1508 and pelvis: 65/48, 455/314, 943/707 and 2261/1595. Sample sizes of clinical images used for the (indirect) measurements were 1724 for chest without a bucky, 799 for chest with a bucky, 337 for abdomen and 641 for pelvis. The methodology we describe could be applicable to other centres using CR as an imaging modality for paediatrics. Presently, this method is the only practical approach to automatically extract parameters contained in the DICOM header, for the calculation of patient dose values for the CR modality.

  16. Planning Facilities.

    ERIC Educational Resources Information Center

    Flynn, Richard B., Ed.; And Others

    1983-01-01

    Nine articles give information to help make professionals in health, physical education, recreation, dance, and athletics more knowledgeable about planning facilities. Design of natatoriums, physical fitness laboratories, fitness trails, gymnasium lighting, homemade play equipment, indoor soccer arenas, and dance floors is considered. A…

  17. Facilities Management.

    ERIC Educational Resources Information Center

    Bete, Tim, Ed.

    1998-01-01

    Presents responses from Matt McGovern, "School Planning and Management's" Maintenance and Operations columnist, on the issue of school facility maintenance. McGovern does not believe schools will ever likely meet acceptable levels of maintenance, nor use infrared thermography for assessing roofs, outsource all maintenance work, nor find a pressing…

  18. The application and development of radiography technology based on x-ray

    NASA Astrophysics Data System (ADS)

    Chen, Hao; Xu, Zhou; Li, Ming

    2009-07-01

    Modern Radiography technology was combined with radiation physics and modern imaging processing, which was an important branch of information obtainment and processing. We can get the inside information of the object, by the X ray's attenuation when the ray penetrated the object, and depending on the computer's fast processing, we can see the slice imaging of the object. Computerized Tomography, Computerized Laminography, and Digital Radiography were important parts in Radiography. The institute of applied electronics, CAEP in the research of intense radiation had developed several advanced radiation sources and some advanced radiography imaging systems, for example, S-band small spot linear accelerator, full solid state modulator, C-band linear accelerator, high energy Tera-hertz radiation source and CT technology based on cone beam, DR technology, CL Technology etc. Such imaging systems had been applied in industrial NDT/NDE, security check, medical diagnosis, petroleum and gas pipeline inspection system etc.

  19. The use of radiography in the diagnosis of oral conditions in children and adolescents.

    PubMed

    Fogarty, W P; Drummond, B K; Brosnan, M G

    2015-12-01

    Radiography can serve as a useful aid in the diagnosis of numerous oral conditions, with a place in nearly all of the disciplines of dentistry. As such it can have a beneficial role in caring for the oral health of children and adolescents. The following review discusses the use of radiography in the diagnosis of oral conditions in children and adolescents, with particular reference to the diagnosis of dental caries, dental trauma, growth and development and in other dental scenarios, along with the importance of incidental findings. The risks associated with radiation exposure from the use of radiography are discussed, how these need to be balanced with the possible benefits associated with such use, as well as how risks could be minimised. Summary recommendations are also presented, providing an overview of the use of radiography for oral diagnosis in various clinical scenarios for children and adolescents. PMID:26761981

  20. Progress on Converting a NIF Quad to Eight, Petawatt Beams for Advanced Radiography

    SciTech Connect

    Crane, J K

    2009-10-19

    We are converting a quad of NIF beamlines into eight, short-pulse (1-50 ps), petawatt-class beams for advanced radiography and fast ignition experiments. This paper describes progress toward completing this project.

  1. Progress on converting a NIF quad to eight, petawatt beams for advanced radiography

    NASA Astrophysics Data System (ADS)

    Crane, J. K.; Tietbohl, G.; Arnold, P.; Bliss, E. S.; Boley, C.; Britten, G.; Brunton, G.; Clark, W.; Dawson, J. W.; Fochs, S.; Hackel, R.; Haefner, C.; Halpin, J.; Heebner, J.; Henesian, M.; Hermann, M.; Hernandez, J.; Kanz, V.; McHale, B.; McLeod, J. B.; Nguyen, H.; Phan, H.; Rushford, M.; Shaw, B.; Shverdin, M.; Sigurdsson, R.; Speck, R.; Stolz, C.; Trummer, D.; Wolfe, J.; Wong, J. N.; Siders, G. C.; Barty, C. P. J.

    2010-08-01

    We are converting a quad of NIF beamlines into eight, short-pulse (1-50 ps), petawatt-class beams for advanced radiography and fast ignition experiments. This paper describes progress toward completing this project.

  2. Time-resolved and time-integrated radiography of fast reactor fuel elements

    SciTech Connect

    De Volpi, A.

    1981-01-01

    The fast-reactor safety program has some unusual requirements in radiography. Applications may be divided into two areas: time-resolved or time-integrated radiography. The fast-neutron hodoscope has supplied all recent time-resolved cineradiographic in-pile fuel-motion data, and various x-ray and photographic techniques have been used for out-of-pile experiments. Thick containers and the large number of radioactive fuel pins involved in safety research have been responsible for some nonconventional applications of time-integrated radiography of stationary objects. Hodoscopes record fuel-motion during transient experiments at the TREAT reactor in the United States and CABRI in France. Other special techniques have been under development for out-of-pile nondestructive radiography of fuel element subassemblies, including fast-neutron and gamma-ray tomographic methods.

  3. Defective pixel map creation based on wavelet analysis in digital radiography detectors

    NASA Astrophysics Data System (ADS)

    Park, Chun Joo; Lee, Hyoung Koo; Song, William Y.; Achterkirchen, Thorsten Graeve; Kim, Ho Kyung

    2011-04-01

    The application of digital radiography detectors has attracted increasing attention in both medicine and industry. Since the imaging detectors are fabricated by semiconductor manufacturing process over large areas, defective pixels in the detectors are unavoidable. Moreover, the radiation damage due to the routine use of the detectors progressively increases the density of defective pixels. In this study, we present a method of identifying defective pixels in digital radiography detectors based on wavelet analysis. Artifacts generated due to wavelet transformations have been prevented by an additional local threshold method. The proposed method was applied to a sample digital radiography and the result was promising. The proposed method uses a single pair of dark and white images and does not require them to be corrected in gain-and-offset properties. This method will be helpful for the reliable use of digital radiography detectors through the working lifetime.

  4. A survey of digital radiography practice in four South African teaching hospitals: an illuminative study

    PubMed Central

    Nyathi, T; Chirwa, TF; van der Merwe, DG

    2010-01-01

    Purpose: The purpose of this study was to assess radiographer familiarity and preferences with digital radiography in four teaching hospitals and thereafter make recommendations in line with the migration from screen film to digital radiography. Materials and methods: A questionnaire was designed to collect data from either qualified or student radiographers from four teaching hospitals. From the four teaching hospitals, there were a total of 205 potential respondents. Among other things, responses regarding experiences and preferences with digital radiography, quality control procedures, patient dose, advantages and disadvantages of digital radiography were sought. The information collected was based on self-reporting by the participants. The study is exploratory in nature and descriptive statistics were generated from the collected data using Microsoft Excel 2007 and StatsDirect software. Results: Sixty-three out of 205 (31%) radiographers from all the four radiology centers responded to the circulated questionnaire. Only 15% (8) of the qualified radiographers had 4 or more years of experience with digital radiography compared to 68% (36) for the same amount of experience with screen-film radiography. Sixty-one percent (38) of the participants had been exposed to digital radiography during their lectures while at university. A small proportion, 16% (10) of the respondents underwent formal training in quality control procedures on the digital X-ray units they were using. Slightly more than half (55%) of the participants felt it was easier for them to retake an image in digital radiography than in screen film radiography. Conclusion: The results of this survey showed that the participants are familiar with digital radiography and have embraced this relatively new technology as shown by the fact that they can identify both its advantages and disadvantages as applied to clinical practice. However, there are minimal quality control procedures specific to digital

  5. Vapor fraction measurements in a steam-water tube at up to 15 bar using neutron radiography techniques

    NASA Astrophysics Data System (ADS)

    Glickstein, S. S.; Murphy, J. H.; Joo, H.

    1999-11-01

    Real-time neutron radiography has been used to study the dynamic behavior of two-phase flow and measure the time averaged vapor fraction in a heated metal tube containing boiling steam-water operating at up to 15 bar pressure. The neutron radiographic technique is non-intrusive and requires no special transparent window region. This is the first time this technique has been used in an electrically heated pressurized flow loop. This unique experimental method offers the opportunity to observe and record on videotape, flow patterns and transient behavior of two-phase flow inside opaque containers without disturbing the environment. In this study the test sections consisted of stainless steel tubes with a 1.27 cm outer diameter and wall thicknesses of 0.084 and 0.124 cm. The experiments were carried out at the Pennsylvania State University 1 MW TRIGA reactor facility utilizing a Precise Optics neutron radiography camera. The inlet water temperature to the test section was varied between 120°C and 170°C and the flow rate set to 2.3 l/min. Tsat is 200°C at these conditions. The tube was resistively heated by passing high currents (˜1000 A) through the stainless steel wall. Scattering due to water in the ˜1 cm tube is significant and Monte Carlo calculations simulating the experiment were made to correct for this effect on the vapor fraction measurement. Details of the experimental technique, methods for analyzing the data and the results of the experiments are discussed.

  6. Fast neutron (14.5 MeV) radiography: a comparative study

    SciTech Connect

    Klann, R.T.

    1996-07-01

    Fast neutron (14.5 MeV) radiography is a type of non-destructive analysis tool that offers its own benefits and drawbacks. Because cross-sections vary with energy, a different range of materials can be examined with fast neutrons than can be studied with thermal neutrons, epithermal neutrons, or x-rays. This paper details these differences through a comparative study of fast neutron radiography to the other types of radiography available. The most obvious difference among the different types of radiography is in the penetrability of the sources. Fast neutrons can probe much deeper and can therefore obtain details of the internals of thick objects. Good images have been obtained through as much as 15 cm of steel, 10 cm of water, and 15 cm of borated polyethylene. In addition, some objects were identifiable through as much as 25 cm of water or 30 cm of borated polyethylene. The most notable benefit of fast neutron radiography is in the types of materials that can be tested. Fast neutron radiography can view through materials that simply cannot be viewed by X rays, thermal neutrons, or epithermal neutrons due to the high cross-sections or linear attenuation coefficients involved. Cadmium was totally transparent to the fast neutron source. Fast neutron radiography is not without drawbacks. The most pronounced drawback has been in the quality of radiograph produced. The image resolution is only about 0.8 mm for a 1.25 cm thick object, whereas, other forms of radiography have much better resolution.

  7. Time resolved analysis of water drainage in porous asphalt concrete using neutron radiography.

    PubMed

    Poulikakos, L D; Sedighi Gilani, M; Derome, D; Jerjen, I; Vontobel, P

    2013-07-01

    Porous asphalt as a road surface layer controls aquaplaning as rain water can drain through its highly porous structure. The process of water drainage through this permeable layer is studied using neutron radiography. Time-resolved water configuration and distribution within the porous structure are reported. It is shown that radiography depicts the process of liquid water transport within the complex geometry of porous asphalt, capturing water films, filled dead end pores and water islands. PMID:23500651

  8. Application of Digital Radiography to Weld Inspection for the Space Shuttle External Fuel Tank

    NASA Technical Reports Server (NTRS)

    Ussery, Warren

    2009-01-01

    This slide presentation reviews NASA's use of digital radiography to inspect the welds of the external tanks used to hold the cryogenic fuels for the Space Shuttle Main Engines. NASA has had a goal of replacing a significant portion of film used to inspect the welds, with digital radiography. The presentation reviews the objectives for converting to a digital system from film, the characteristics of the digital system, the Probability of detection study, the qualification and implementation of the system.

  9. Impact of Chest Radiography for Children with Lower Respiratory Tract Infection: A Propensity Score Approach

    PubMed Central

    Ecochard-Dugelay, Emmanuelle; Beliah, Muriel; Boisson, Caroline; Perreaux, Francis; de Laveaucoupet, Jocelyne; Labrune, Philippe; Epaud, Ralph; Ducou-Lepointe, Hubert; Bouyer, Jean; Gajdos, Vincent

    2014-01-01

    Background Management of acute respiratory tract infection varies substantially despite this being a condition frequently encountered in pediatric emergency departments. Previous studies have suggested that the use of antibiotics was higher when chest radiography was performed. However none of these analyses had considered the inherent indication bias of observational studies. Objective The aim of this work was to assess the relationship between performing chest radiography and prescribing antibiotics using a propensity score analysis to address the indication bias due to non-random radiography assignment. Methods We conducted a prospective study of 697 children younger than 2 years of age who presented during the winter months of 2006–2007 for suspicion of respiratory tract infection at the Pediatric Emergency Department of an urban general hospital in France (Paris suburb). We first determined the individual propensity score (probability of having a chest radiography according to baseline characteristics). Then we assessed the relation between radiography and antibiotic prescription using two methods: adjustment and matching on the propensity score. Results We found that performing a chest radiography lead to more frequent antibiotic prescription that may be expressed as OR = 2.3, CI [1.3–4.1], or as an increased use of antibiotics of 18.6% [0.08–0.29] in the group undergoing chest radiography. Conclusion Chest radiography has a significant impact on the management of infants admitted for suspicion of respiratory tract infection in a pediatric emergency department and may lead to unnecessary administration of antibiotics. PMID:24788944

  10. Dynamic chest radiography: flat-panel detector (FPD) based functional X-ray imaging.

    PubMed

    Tanaka, Rie

    2016-07-01

    Dynamic chest radiography is a flat-panel detector (FPD)-based functional X-ray imaging, which is performed as an additional examination in chest radiography. The large field of view (FOV) of FPDs permits real-time observation of the entire lungs and simultaneous right-and-left evaluation of diaphragm kinetics. Most importantly, dynamic chest radiography provides pulmonary ventilation and circulation findings as slight changes in pixel value even without the use of contrast media; the interpretation is challenging and crucial for a better understanding of pulmonary function. The basic concept was proposed in the 1980s; however, it was not realized until the 2010s because of technical limitations. Dynamic FPDs and advanced digital image processing played a key role for clinical application of dynamic chest radiography. Pulmonary ventilation and circulation can be quantified and visualized for the diagnosis of pulmonary diseases. Dynamic chest radiography can be deployed as a simple and rapid means of functional imaging in both routine and emergency medicine. Here, we focus on the evaluation of pulmonary ventilation and circulation. This review article describes the basic mechanism of imaging findings according to pulmonary/circulation physiology, followed by imaging procedures, analysis method, and diagnostic performance of dynamic chest radiography. PMID:27294264

  11. Diagnostic Accuracy of Cone-Beam Computed Tomography and Periapical Radiography in Internal Root Resorption

    PubMed Central

    Madani, Zahrasadat; Moudi, Ehsan; Bijani, Ali; Mahmoudi, Elham

    2016-01-01

    Introduction: The aim of this study was to compare the diagnostic value of cone-beam computed tomography (CBCT) and periapical (PA) radiography in detecting internal root resorption. Methods and Materials: Eighty single rooted human teeth with visible pulps in PA radiography were split mesiodistally along the coronal plane. Internal resorption like lesions were created in three areas (cervical, middle and apical) in labial wall of the canals in different diameters. PA radiography and CBCT images were taken from each tooth. Two observers examined the radiographs and CBCT images to evaluate the presence of resorption cavities. The data were statistically analyzed and degree of agreement was calculated using Cohen’s kappa (k) values. Results: The mean±SD of agreement coefficient of kappa between the two observers of the CBCT images was calculated to be 0.681±0.047. The coefficients for the direct, mesial and distal PA radiography were 0.405±0.059, 0.421±0.060 and 0.432±0.056, respectively (P=0.001). The differences in the diagnostic accuracy of resorption of different sizes were statistically significant (P<0.05); however, the PA radiography and CBCT, had no statistically significant differences in detection of internal resorption lesions in the cervical, middle and apical regions. Conclusion: Though, CBCT has a higher sensitivity, specificity, positive predictive value and negative predictive value in comparison with conventional radiography, this difference was not significant. PMID:26843878

  12. Development of backlighting sources for a Compton radiography diagnostic of inertial confinement fusion targets (invited)a)

    NASA Astrophysics Data System (ADS)

    Tommasini, R.; MacPhee, A.; Hey, D.; Ma, T.; Chen, C.; Izumi, N.; Unites, W.; MacKinnon, A.; Hatchett, S. P.; Remington, B. A.; Park, H. S.; Springer, P.; Koch, J. A.; Landen, O. L.; Seely, John; Holland, Glenn; Hudson, Larry

    2008-10-01

    We present scaled demonstrations of backlighter sources, emitting bremsstrahlung x rays with photon energies above 75keV, that we will use to record x-ray Compton radiographic snapshots of cold dense DT fuel in inertial confinement fusion implosions at the National Ignition Facility (NIF). In experiments performed at the Titan laser facility at Lawrence Livermore National Laboratory, we measured the source size and the bremsstrahlung spectrum as a function of laser intensity and pulse length from solid targets irradiated at 2×1017-5×1018W/cm2 using 2-40ps pulses. Using Au planar foils we achieved source sizes down to 5.5μm and conversion efficiencies of about 1×10-13J/J into x-ray photons with energies in the 75-100keV spectral range. We can now use these results to design NIF backlighter targets and shielding and to predict Compton radiography performance as a function of the NIF implosion yield and associated background.

  13. The new neutron radiography/tomography/imaging station DINGO at OPAL

    NASA Astrophysics Data System (ADS)

    Garbe, U.; Randall, T.; Hughes, C.

    2011-09-01

    A new neutron imaging instrument will be built to support the area of neutron imaging research (neutron radiography/tomography) at ANSTO. The instrument will be designed for an international user community and for routine quality control for defence, industrial, mining, space and aircraft applications. It will also be a useful tool for assessing oil and water flow in sedimentary rock reservoirs (like the North West Shelf), assessing water damage in aircraft components, and the study of hydrogen distribution and cracking in steel. The instrument is planned to be completed by the end of June 2013 and is currently in the design stage. The usable neutron flux is mainly determined by the neutron source, but it also depends on the instrument position and the resolution. The designated instrument position for DINGO is the beam port HB-2 in the reactor hall. The estimated flux for an L/ D of approximately 250 at HB-2 is calculated by Mcstas simulation in a range of 4.75×10 7 n/cm 2 s, which is in the same range of other facilities like ANSTARES (FRM II; Schillinger et al., 2004 [1]) or BT2 (NIST; Hussey et al., 2005 [2]). A special feature of DINGO is the in-pile collimator place in front of the main shutter at HB-2. The collimator offers two pinholes with a possible L/ D of 250 and 1000. A secondary collimator will separate the two beams and block one. The whole instrument will operate in two different positions, one for high resolution and the other for high speed.

  14. SU-E-I-27: Establishing Target Exposure Index Values for Computed Radiography

    SciTech Connect

    Murphy, N; Tchou, P; Belcher, K; Scott, A

    2014-06-01

    Purpose: To develop a standard set of target exposure index (TEI) values to be applied to Agfa Computed Radiography (CR) readers in accordance with International Electrotechnical Committee 62494-1 (ed. 1.0). Methods: A large data cohort was collected from six USAF Medical Treatment Facilities that exclusively use Agfa CR Readers. Dose monitoring statistics were collected from each reader. The data was analyzed based on anatomic region, view, and processing speed class. The Agfa specific exposure metric, logarithmic mean (LGM), was converted to exposure index (EI) for each data set. The optimum TEI value was determined by minimizing the number of studies that fell outside the acceptable deviation index (DI) range of +/− 2 for phototimed techniques or a range of +/−3 for fixed techniques. An anthropomorphic radiographic phantom was used to corroborate the TEI recommendations. Images were acquired of several anatomic regions and views using standard techniques. The images were then evaluated by two radiologists as either acceptable or unacceptable. The acceptable image with the lowest exposure and EI value was compared to the recommended TEI values using a passing DI range. Results: Target EI values were determined for a comprehensive list of anatomic regions and views. Conclusion: Target EI values must be established on each CR unit in order to provide a positive feedback system for the technologist. This system will serve as a mechanism to prevent under or overexposures of patients. The TEI recommendations are a first attempt at a large scale process improvement with the goal of setting reasonable and standardized TEI values. The implementation and effectiveness of the recommended TEI values should be monitored and adjustments made as necessary.

  15. Digital reconstructed radiography quality control with software methods

    NASA Astrophysics Data System (ADS)

    Denis, Eloise; Beaumont, Stephane; Guedon, JeanPierre

    2005-04-01

    Nowadays, most of treatments for external radiotherapy are prepared with Treatment Planning Systems (TPS) which uses a virtual patient generated by a set of transverse slices acquired with a CT scanner of the patient in treatment position 1 2 3. In the first step of virtual simulation, the TPS is used to define a ballistic allowing a good target covering and the lowest irradiation for normal tissues. This parameters optimisation of the treatment with the TPS is realised with particular graphic tools allowing to: ×Contour the target, ×Expand the limit of the target in order to take into account contouring uncertainties, patient set up errors, movements of the target during the treatment (internal movement of the target and external movement of the patient), and beam's penumbra, ×Determine beams orientation and define dimensions and forms of the beams, ×Visualize beams on the patient's skin and calculate some characteristic points which will be tattooed on the patient to assist the patient set up before treating, ×Calculate for each beam a Digital Reconstructed Radiography (DRR) consisting in projecting the 3D CT virtual patient and beam limits with a cone beam geometry onto a plane. These DRR allow one for insuring the patient positioning during the treatment, essentially bone structures alignment by comparison with real radiography realized with the treatment X-ray source in the same geometric conditions (portal imaging). Then DRR are preponderant to insure the geometric accuracy of the treatment. For this reason quality control of its computation is mandatory4 . Until now, this control is realised with real test objects including some special inclusions4 5 . This paper proposes to use some numerical test objects to control the quality DRR calculation in terms of computation time, beam angle, divergence and magnification precision, spatial and contrast resolutions. The main advantage of this proposed method is to avoid a real test object CT acquisition

  16. EOS imaging versus current radiography: A health technology assessment study

    PubMed Central

    Mahboub-Ahari, Alireza; Hajebrahimi, Sakineh; Yusefi, Mahmoud; Velayati, Ashraf

    2016-01-01

    Background: EOS is a 2D/3D muscle skeletal diagnostic imaging system. The device has been developed to produce a high quality 2D, full body radiographs in standing, sitting and squatting positions. Three dimensional images can be reconstructed via sterEOS software. This Health Technology Assessment study aimed to investigate efficacy, effectiveness and cost-effectiveness of new emerged EOS imaging system in comparison with conventional x-ray radiographic techniques. Methods: All cost and outcome data were assessed from Iran's Ministry of Health Perspective. Data for clinical effectiveness was extracted using a rigorous systematic review. As clinical outcomes the rate of x-ray emission and related quality of life were compared with Computed Radiography (CR) and Digital Radiography (DR). Standard costing method was conducted to find related direct medical costs. In order to examine robustness of the calculated Incremental Cost Effectiveness Ratios (ICERs) we used two-way sensitivity analysis. GDP Per capita of Islamic Republic of Iran (2012) adopted as cost-effectiveness threshold. Results: Review of related literature highlighted the lack of rigorous evidence for clinical outcomes. Ultra low dose EOS imaging device is known as a safe intervention because of FDA, CE and CSA certificates. The rate of emitted X-ray was 2 to 18 fold lower for EOS compared to the conventional techniques (p<0.001). The Incremental Cost Effectiveness Ratio for EOS relative to CR calculated $50706 in baseline analysis (the first scenario) and $50714, $9446 respectively for the second and third scenarios. Considering the value of neither $42146 as upper limit, nor the first neither the second scenario could pass the cost-effectiveness threshold for Iran. Conclusion: EOS imaging technique might not be considered as a cost-effective intervention in routine practice of health system, especially within in-patient wards. Scenario analysis shows that, only in an optimum condition such as lower

  17. Evaluation of entrance surface air kerma in pediatric chest radiography

    NASA Astrophysics Data System (ADS)

    Porto, L.; Lunelli, N.; Paschuk, S.; Oliveira, A.; Ferreira, J. L.; Schelin, H.; Miguel, C.; Denyak, V.; Kmiecik, C.; Tilly, J.; Khoury, H.

    2014-11-01

    The objective of this study was to evaluate the entrance surface air kerma in pediatric chest radiography. An evaluation of 301 radiographical examinations in anterior-posterior (AP) and posterior-anterior (PA) (166 examinations) and lateral (LAT) (135 examinations) projections was performed. The analyses were performed on patients grouped by age; the groups included ages 0-1 y, 1-5 y, 5-10 y, and 10-15 y. The entrance surface air kerma was determined with DoseCal software (Radiological Protection Center of Saint George's Hospital, London) and thermoluminescent dosimeters. Two different exposure techniques were compared. The doses received by patients who had undergone LAT examinations were 40% higher, on average, those in AP/PA examinations because of the difference in tube voltage. A large high-dose “tail” was observed for children up to 5 y old. An increase in tube potential and corresponding decrease in current lead to a significant dose reduction. The difference between the average dose values for different age ranges was not practically observed, implying that the exposure techniques are still not optimal. Exposure doses received using the higher tube voltage and lower current-time product correspond to the international diagnostic reference levels.

  18. Reduction of absorbed doses in radiography of the facial skeleton

    SciTech Connect

    Julin, P.; Kraepelien, T.

    1984-11-01

    Radiation absorbed doses from radiography of the paranasal sinuses and the facial skeleton were measured with thermoluminescent dosimeters (TLD) on a phantom head using high-sensitivity screens in an Orbix stand. The entrance doses to the skin of the head ranged from 0.31 to 2.9 mGy per exposure. The absorbed dose from a full series of sinus exposures averaged 0.33 mGy for the oral mucous membrane, 0.33 mGy for the maxillary sinus mucous membrane, 0.11 mGy for the parotid gland, 0.15 mGy for the submandibular gland, 0.61 mGy for the eye lens, and 0.75 mGy for the thyroid gland region. A leaded soft collar adapted to the thyroid region reduced the thyroid doses by more than one order of magnitude, but also reduced the image field. The mean energy imparted from a full series of paranasal sinus projections was 4.8 mJ and from a total series of the facial skeleton, 7.9 mJ.

  19. Patient exposure trends in medical and dental radiography

    SciTech Connect

    Johnson, D.W.; Goetz, W.A.

    1986-01-01

    Patient exposure to medical and dental x rays has long been of interest to the radiological health community. With the cooperation of state and local agencies and professional groups, the Center for Devices and Radiological Health has conducted three major surveys of patient exposure to x rays. The latest of these surveys, the Nationwide Evaluation of X-ray Trends (NEXT), collected x-ray exposure data for each year starting in 1972. Two earlier studies, the 1964 and 1970 X-ray Exposure Studies collected x-ray data during the years these surveys were conducted. Exposure trends presented are based on results of all three studies. Major improvements in beam limitation are seen for medical and dental radiography. Since 1964, when the first nationwide survey was conducted, dental exposures have decreased about 75%. Decreases of up to one-third occurred in exposures for medical examinations. The current exposure data presented continue to show a wide variation in medical exposures. Also presented are organ doses for four organs (ovaries, testes, thyroid and active bone marrow).

  20. Location of mental foramen using digital panoramic Radiography

    PubMed Central

    Mohamed, Ajmal; Nataraj, Kannan; Mathew, Vinod B.; Varma, Beena; Mohamed, Shamil; Valappila, Nidhin J.; Meena, Aravind S.

    2016-01-01

    Objective: Comparative evaluation of the location of mental foramen in different age groups. Determine the variation in position of mental foramen with gender using digital panoramic radiography. Materials and Methods: Digital panoramic radiographs of 250 patients were reviewed. The study population was divided into five age groups with 50 patients each. Radiographic position of mental foramen was evaluated in each radiograph based on three parameters. Measurements were taken in each radiograph using Planmeca Dimaxis pro version 4.4.0 (Helsinki, Finland). The collected data were subjected to statistical analysis using paired Student's t-test. Results: The mean distance of position of mental foramen showed a significant variation within the five age groups. In the first group, female patients showed an increase in mean distance of mental foramen position in relation to three parameters. From the second to fifth groups, male patient showed an increase in the mean distance of mental foramen position. The first and fifth group showed a reduced mean distance of mental foramen position when compared to other age groups. Conclusion: This study concluded that the position of mental foramen varies with age. There was a gender-related variation in position of mental foramen within the population too. PMID:27555723

  1. Reconstruction of Material Elemental Composition Using Fast Neutron Resonance Radiography

    NASA Astrophysics Data System (ADS)

    Mor, Ilan; Dangendorf, Volker; Reginatto, Marcel; Kaufmann, Frank; Vartsky, David; Brandis, Michal; Bar, Doron; Goldberg, Mark B.

    Fast neutron resonance radiography (FNRR) is an imaging method that exploits characteristic cross-section structures (peaks and troughs) of certainelements in the energy-range of 1-10 MeV to identify materials in a large volume object. In FNRR, the neutron energy spectrum transmitted through an object carries information about the elemental composition of thatobject. The principal elements present in most explosives are: carbon, oxygen, nitrogen andhydrogen. Explosives are characterized by high fractions of nitrogen and oxygen as well as low fractions of carbon and hydrogencompared to benign materials. Detection of explosives in cargo employing FNRRis based on determination of the local areal densities of these four elements and their ratios. In our measurements, the transmission spectrum is usually divided in 100 - 500 energy bins, representing 100 - 500 linear equations containing four unknown areal densities of HCNO. This is an overdetermined problem, which allows us to derive not only the fourexpectation values of their areal densitiesbut theirprobability distribution as well. For this purpose, a model was formulated and implemented within a software package which performs Bayesian analysis of complex statistical models using Markov chain Monte-Carlo (MCMC). This model was tested successfully both on simulated and experimental data. This work will describe the model and the outcome of elemental ratios reconstruction for several materials from experimental data.

  2. Normal Age-Related Alterations on Distal Radius Radiography

    PubMed Central

    Namazi, Hamid; Khaje, Rohallah

    2015-01-01

    Background: The present study was designed to ascertain serial changes on distal radius radiographic parameters attributable to aging. Methods: In this prospective study, the sample consisted of 120 healthy individuals who were divided into four age groups each containing 15 males and 15 females. In the two below-20-year-old groups, only ulnar variance could be investigated. Wrist radiography was taken and then parameters of the distal radius were measured and compared based on age and sex. Results: Average UV was -2.48 mm and -1.6 mm in the 2-9 and 10-19-year-old age groups, respectively. Also, in the two above-20-year-old groups, the average radial inclination (RI), palmar tilt (PT), radial length (RL), and UV was 23.7º, 12.4º, 10.5 and +1.1 mm, respectively. Considering ulnar variance, no significant difference was found between the 2-9- and 10-19-year-old groups, as well as among the two above-20-year-old groups. However, a significant difference was observed between the below 20 and above 20 groups. The study results showed no significant differences between males and females in any of the study groups. Discussion: There is significant ulnar variance change toward less negative ulnar variance with aging until maturity. PMID:26550588

  3. Thermal Neutron Radiography of Deuteriated Water in Soils

    NASA Astrophysics Data System (ADS)

    Tumlinson, L. G.; Hopmans, J. W.; Wilding, M. C.; Silk, W. K.; Huerta, N. J.; Tabor, M. M.

    2004-12-01

    As for x-rays, neutron radiography is a noninvasive imaging technique based on the attenuation of thermal neutrons by the object in question, described by BeerAƒAøAøâ_sA¬Aøâ_zAøs law. However, neutron imaging is complementary to x-rays, as it is especially well suited for materials containing hydrogen atoms and mostly other low atomic weight attenuating materials. Although neutron attenuation techniques are routinely used in engineering, relatively little is known about its application to soils. We will present results demonstrating the tremendous potential of using neutron attenuation techniques to measure spatial and temporal distribution of water in soils at the 50 micrometer spatial resolution. The neutron source is a Mark II Triga Reactor at McClellan Nuclear Radiation Center (MNRC) in Sacramento, CA. The reactor runs at 1.8 MW and emits a poly-energetic neutron beam, including the thermal range. Unfortunately beam hardening and backscattering are a major source of uncertainty. Recent laboratory experiments conducted at MNRC suggest that beam hardening is considerably reduced when using deuteriated water, because its cross-section for attenuation of thermal neutrons is much lower than for regular water.

  4. Magnification Embossed Radiography Utilizing Image-Shifting Subtraction Program

    NASA Astrophysics Data System (ADS)

    Akihiro Osawa,; Manabu Watanabe,; Eiichi Sato,; Hiroshi Matsukiyo,; Toshiyuki Enomoto,; Jiro Nagao,; Purkhet Abderyim,; Katsuo Aizawa,; Etsuro Tanaka,; Hidezo Mori,; Toshiaki Kawai,; Akira Ogawa,; Kiyomi Takahashi,; Shigehiro Sato,; Jun Onagawa,

    2010-03-01

    We developed an image-shifting subtraction program and carried out magnification embossed radiography (MER) utilizing single- and dual-energy subtractions. In particular, dual-energy subtraction was carried out to decrease the absorption contrast of unnecessary regions. The contrast resolution of the target region was increased by the use of subtraction software and a linear-contrast system in a flat-panel detector (FPD). The X-ray generator had a 100-μm-focus tube, and the subtractions were performed at tube voltages of 40 and 70 kV, a tube current of 0.50 mA, and an X-ray exposure time of 5.0 s. MER images with threefold magnification were obtained using the FPD with a pixel size of 48× 48 μm2, and the shifting dimensions of the imaged object in the horizontal and vertical directions ranged from 48 to 192 μm. At a shifting distance ranging from 48 to 144 μm, the spatial resolutions in the horizontal and vertical directions measured with a lead test chart were both 50 μm. In the MER of nonliving animals, we obtained high-contrast embossed images of fine bones, gadolinium oxide particles in blood vessels, and iodine-based microspheres in coronary arteries of approximately 100 μm diameter.

  5. Embossed radiography utilizing an image-shifting subtraction program

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Osawa, Akihiro; Matsukiyo, Hiroshi; Enomoto, Toshiyuki; Watanabe, Manabu; Takahashi, Kiyomi; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

    2010-07-01

    We developed an image-shifting subtraction program and carried out embossed radiography (ER) utilizing single- and dual-energy subtractions. In particular, dual-energy subtraction was carried out to decrease the absorption contrast of unnecessary regions. The contrast resolution of a target region was increased using the subtraction program and a linear-contrast system in a flat panel detector (FPD). The X-ray generator had a 100 μm-focus tube, and the subtractions were performed at tube voltages of 40 and 70 kV, a tube current of 0.50 mA, and an X-ray exposure time of 5.0 s. ER was achieved with cohesion imaging using the FPD with pixel sizes of 48×48 μm 2, and the shifting dimension of an object in the horizontal and vertical directions ranged from 48 to 96 μm. At a shifting distance of 96 μm, the spatial resolutions in the horizontal and vertical directions measured with a lead test chart were both 83 μm. In ER of animal phantoms, we obtained high-contrast embossed images of fine bones, gadolinium oxide particles in blood vessels, iodine-based microspheres in coronary arteries approximately 100 μm in diameter.

  6. Magnification Embossed Radiography Utilizing Image-Shifting Subtraction Program

    NASA Astrophysics Data System (ADS)

    Osawa, Akihiro; Watanabe, Manabu; Sato, Eiichi; Matsukiyo, Hiroshi; Enomoto, Toshiyuki; Nagao, Jiro; Abderyim, Purkhet; Aizawa, Katsuo; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ogawa, Akira; Takahashi, Kiyomi; Sato, Shigehiro; Onagawa, Jun

    2010-03-01

    We developed an image-shifting subtraction program and carried out magnification embossed radiography (MER) utilizing single- and dual-energy subtractions. In particular, dual-energy subtraction was carried out to decrease the absorption contrast of unnecessary regions. The contrast resolution of the target region was increased by the use of subtraction software and a linear-contrast system in a flat-panel detector (FPD). The X-ray generator had a 100-µm-focus tube, and the subtractions were performed at tube voltages of 40 and 70 kV, a tube current of 0.50 mA, and an X-ray exposure time of 5.0 s. MER images with threefold magnification were obtained using the FPD with a pixel size of 48×48 µm2, and the shifting dimensions of the imaged object in the horizontal and vertical directions ranged from 48 to 192 µm. At a shifting distance ranging from 48 to 144 µm, the spatial resolutions in the horizontal and vertical directions measured with a lead test chart were both 50 µm. In the MER of nonliving animals, we obtained high-contrast embossed images of fine bones, gadolinium oxide particles in blood vessels, and iodine-based microspheres in coronary arteries of approximately 100 µm diameter.

  7. Comparison Of Modified Bootstrap And Conventional Sensitometry In Medical Radiography

    NASA Astrophysics Data System (ADS)

    Bednarek, Daniel R.; Rudin, Stephen

    1980-08-01

    A new modified bootstrap approach to sensitometry is presented which provides H and D curves that show almost exact agreement with those obtained using conventional methods. Two bootstrap techniques are described; both involve a combination of inverse-square and step-ped wedge modulation of the radiation field and provide intensity-scale sensitometric curves as appropriate for medical radiography. H and D curves obtained with these modified techniques are compared with those obtained for screen-film combinations using inverse-square sensitometry as well as with those obtained for direct x-ray film using time-scale sensitometry. The stepped-wedge of the Wisconsin X-Ray Test Cassette was used in the boot-strap approach since it provides sufficient exposure latitude to encompass the useful den-sity range of medical x-ray film. This approach makes radiographic sensitometry quick and convenient, allowing accurate characteristic curves to be obtained for any screen-film cassette using standard diagnostic equipment.

  8. Asymptomatic Intracranial Foreign Body: An Incidental Finding on Radiography

    PubMed Central

    Maghsoudi, Mohammadreza; Shahbazzadegan, Bita; Pezeshki, Arastoo

    2016-01-01

    Introduction Intracranial needles are rare entities. Intracranial foreign bodies due to non-missile intracranial penetrations are one of the most rarely encountered situations in neurosurgery. Sewing needles are among the more unusual foreign bodies that may be found in the brain. Although uncommon, foreign body cases are important and interesting. Foreign bodies enter the body through trauma or iatrogenic injuries. Needles are mostly inserted through fontanelles, cranial sutures, and more rarely through the orbits in infancy for the purpose of killing unwanted babies. Case Presentation This article presents a case of intracranial foreign body found upon radiography. A 24-year-old female, who two days prior to presentation suffered only once from dizziness, and was otherwise healthy. Conclusions Because this incident may have occurred during the patient’s neonatal period, it may be a case of child abuse. In spite of the very limited number of cases in the literature, having a stepmother, a stepfather, or a babysitter, being the youngest child, or having family members who suffer from psychiatric disorders, (especially if these relatives are responsible for child care), living in a society that allows homicide of children born from extramarital relationships, and being female have been suggested as possible risk factors. PMID:27626006

  9. Accuracy of real time radiography burning rate measurement

    NASA Astrophysics Data System (ADS)

    Olaniyi, Bisola

    The design of a solid propellant rocket motor requires the determination of a propellant's burning-rate and its dependency upon environmental parameters. The requirement that the burning-rate be physically measured, establishes the need for methods and equipment to obtain such data. A literature review reveals that no measurement has provided the desired burning rate accuracy. In the current study, flash x-ray modeling and digitized film-density data were employed to predict motor-port area to length ratio. The pre-fired port-areas and base burning rate were within 2.5% and 1.2% of their known values, respectively. To verify the accuracy of the method, a continuous x-ray and a solid propellant rocket motor model (Plexiglas cylinder) were used. The solid propellant motor model was translated laterally through a real-time radiography system at different speeds simulating different burning rates. X-ray images were captured and the burning-rate was then determined. The measured burning rate was within 1.65% of the known values.

  10. Kinematic radiography of the hip joint after hip resurfacing arthroplasty.

    PubMed

    Kawashima, Hiroki; Kajino, Yoshitomo; Kabata, Tamon; Tsuchiya, Hiroyuki; Sanada, Shigeru; Ichikawa, Katsuhiro

    2016-07-01

    This study aimed to evaluate the usefulness of dynamic radiography using a dynamic flat-panel detector (FPD) system after hip resurfacing arthroplasty (HRA). A total of 32 hips of 26 patients who underwent HRA were included. Sequential images of active abduction in the supine position and flexion in the 45° semilateral position were obtained using the FPD system. We examined the imaging findings of impingement between the acetabular component and femoral neck with cooperative motion at maximal exercise. Moreover, the central component coordinate of the acetabulum and femoral head sides was measured. For abduction motion, impingement was detected in two (6.3 %) hips between the superior portion of the femoral neck and acetabular component. For flexion motion, impingement was detected in 19 (59.4 %) hips. There were no findings of subluxation between the acetabular component and femoral neck after impingement, but cooperative motion of lumbar and pelvic flexion was observed. There was no significant difference in the center-to-center distance regardless of the presence or absence of impingement. Detailed postoperative kinematics of the hips after HRA showed that the proposed dynamic FPD system could reveal acquired impingement and cooperative motion as dynamic images and possibly reveal findings that would be unobservable using static images. PMID:27207072

  11. Optimization of the radiological protection of patients undergoing digital radiography.

    PubMed

    Zhang, Menglong; Chu, Cunkun

    2012-02-01

    Because of a much higher dynamic range of flat panel detectors, patient dose can vary without change of image quality being perceived by radiologists. This condition makes optimization (OT) of radiation protection undergoing digital radiography (DR) more complex, while a chance to reduced patient dose also exists. In this study, we evaluated the difference of patient radiation and image rejection before and after OT to identify if it is necessary to carry out an OT procedure in a routine task with DR. The study consisted of a measurement of the dose area product (DAP) and entrance surface dose (ESD) received by a reference group of patients for eight common radiographic procedures using the DR system before and after OT. Meanwhile image rejection data during two 2-month periods were collected and sorted according to reason. For every radiographic procedure, t tests showed significant difference in average ESD and DAP before and after OT (p < 0.005). The ESDs from most examinations before OT were three times higher than that after OT. For DAPs, the difference is more significant. Image rejection rate after OT is significantly lower than that before OT (χ (2) = 36.5, p < 0.005). The substantial reductions of dose after OT resulted from appropriate mAs and exposure field. For DR patient dose, less than recommended diagnostic reference level can meet quality criteria and clinic diagnosis. PMID:21725621

  12. Preprocessing functions for computed radiography images in a PACS environment

    NASA Astrophysics Data System (ADS)

    McNitt-Gray, Michael F.; Pietka, Ewa; Huang, H. K.

    1992-05-01

    In a picture archiving and communications system (PACS), images are acquired from several modalities including computed radiography (CR). This modality has unique image characteristics and presents several problems that need to be resolved before the image is available for viewing at a display workstation. A set of preprocessing functions have been applied to all CR images in a PACS environment to enhance the display of images. The first function reformats CR images that are acquired with different plate sizes to a standard size for display. Another function removes the distracting white background caused by the collimation used at the time of exposure. A third function determines the orientation of each image and rotates those images that are in nonstandard positions into a standard viewing position. Another function creates a default look-up table based on the gray levels actually used by the image (instead of allocated gray levels). Finally, there is a function which creates (for chest images only) the piece-wise linear look-up tables that can be applied to enhance different tissue densities. These functions have all been implemented in a PACS environment. Each of these functions have been very successful in improving the viewing conditions of CR images and contribute to the clinical acceptance of PACS by reducing the effort required to display CR images.

  13. Digital Radiography and Computed Tomography (DRCT) Product Improvement Plan (PIP)

    SciTech Connect

    Tim Roney; Bob Pink; Karen Wendt; Robert Seifert; Mike Smith

    2010-12-01

    The Idaho National Laboratory (INL) has been developing and deploying x-ray inspection systems for chemical weapons containers for the past 12 years under the direction of the Project Manager for Non-Stockpile Chemical Materiel (PMNSCM). In FY-10 funding was provided to advance the capabilities of these systems through the DRCT (Digital Radiography and Computed Tomography) Product Improvement Plan (PIP), funded by the PMNSCM. The DRCT PIP identified three research tasks; end user study, detector evaluation and DRCT/PINS integration. Work commenced in February, 2010. Due to the late start and the schedule for field inspection of munitions at various sites, it was not possible to spend sufficient field time with operators to develop a complete end user study. We were able to interact with several operators, principally Mr. Mike Rowan who provided substantial useful input through several discussions and development of a set of field notes from the Pueblo, CO field mission. We will be pursuing ongoing interactions with field personnel as opportunities arise in FY-11.

  14. Dual, orthogonal, backlit pinhole radiography in OMEGA experiments

    NASA Astrophysics Data System (ADS)

    Kuranz, C. C.; Blue, B. E.; Drake, R. P.; Robey, H. F.; Hansen, J. F.; Knauer, J. P.; Grosskopf, M. J.; Krauland, C.; Marion, D. C.

    2006-10-01

    Backlit pinhole radiography used with ungated film as a detector creates x-ray radiographs with increased resolution and contrast. Current hydrodynamics experiments on the OMEGA Laser use a three-dimensional sinusoidal pattern as a seed perturbation for the study of instabilities. The structure of this perturbation makes it highly desirable to obtain two simultaneous orthogonal backlighting views. We accomplished this using two backlit pinholes each mounted 12mm from the target. The pinholes, of varying size and shape, were centered on 5mm square foils of 50μm thick Ta. The backlighting is by K-alpha emission from a 500μm square Ti or Sc foil mounted 500μm from the Ta on a plastic substrate. Four laser beams overfill the metal foil, so that the expanding plastic provides radial tamping of the expanding metal plasma. The resulting x-rays pass through the target onto (ungated) direct exposure film (DEF). Interference between the two views is reduced by using a nose cone in front of the DEF, typically with a 9mm Ta aperture and with magnets to deflect electrons. Comparison of varying types of pinholes and film exposures will be presented from recent experiments as well as an analysis of the background noise created using this experimental technique.

  15. A Repetitional Pulsed X-Ray Generator For Biomedical Radiography

    NASA Astrophysics Data System (ADS)

    Isobe, Hiroshi; Sato, Eiichi; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1989-06-01

    A repetitional pulsed x-ray generator in conjunction with an image intensifier system for biomedical radiography is described. This generator consisted of the following components: a high-speed power supply, various capacities of pulse condensers, a turbo molecular pump, and an oil-cooled x-ray tube. The pulse condensers were charged to the optimum voltage of less than 100kV, and the electric charges were discharged repeatedly by using the flashover mechanism. The pulse width tended to decrease when the capacity and the anode-cathode(A-C) space were reduced, and their values were less than 200ns. The current of the power supply determined the repetitional rates for the pulses, which were limited by the charging resistor, the condenser capacity, the charging voltage, and the electric power of the power supply. The maximum value was less than 20Hz due to the ripples of the charging current of 50Hz. The x-ray quality primarily became hard by increasing the charging voltage, and inserting metal filters. The effective focal spot size primarily varied according to the diameter of anode tip, and its size was less than 3.0mm in diameter. Pulsed x-ray fluoro-scopy was performed by using an image intensifier system utilizing a CRT for medical use.

  16. Proton Radiography Experiment to Visualize Gas Bubbles in Mercury

    SciTech Connect

    Riemer, Bernie; Felde, David K; Wendel, Mark W; Mariam, Fesseha G; Merrill, Frank E

    2007-01-01

    An experiment to visualize small gas bubbles injected into mercury flowing in a test loop using proton radiography was conducted at the Los Alamos Neutron Science Center (LANSCE) in December 2006. Radiograph images of bubbles were obtained through two mercury thicknesses: 22 mm and 6 mm. Two jet bubblers and two needle bubblers were operated individually over a range of mercury flow speeds (0 - 1 m/s) and gas injection rates (0.1 - 500 sccm). Helium was most commonly used but Argon and Xenon were injected for limited test conditions. The smallest discernable bubbles were about 0.24 mm in diameter. Resolution was limited by image contrast which was notably improved with 6 mm of mercury thickness. Analysis of the radiograph images from jet bubbler conditions provided data on bubble size distribution and total bubble void fraction. In a few cases radiographs captured a large fraction of the injected gas, but generally 20 to 90% of injected gas was not captured in the images. In all more than 400 radiographs were made during the experiment in addition to several movies. Sound recordings of needle bubbler operation were also made and used to quantify bubble formation rate and size; these results are compared to theoretical predictions. This paper describes the experiment goals, scope and equipment; key results are presented and discussed.

  17. Scale analysis using X-ray microfluorescence and computed radiography

    NASA Astrophysics Data System (ADS)

    Candeias, J. P.; de Oliveira, D. F.; dos Anjos, M. J.; Lopes, R. T.

    2014-02-01

    Scale deposits are the most common and most troublesome damage problems in the oil field and can occur in both production and injection wells. They occur because the minerals in produced water exceed their saturation limit as temperatures and pressures change. Scale can vary in appearance from hard crystalline material to soft, friable material and the deposits can contain other minerals and impurities such as paraffin, salt and iron. In severe conditions, scale creates a significant restriction, or even a plug, in the production tubing. This study was conducted to qualify the elements present in scale samples and quantify the thickness of the scale layer using synchrotron radiation micro-X-ray fluorescence (SRμXRF) and computed radiography (CR) techniques. The SRμXRF results showed that the elements found in the scale samples were strontium, barium, calcium, chromium, sulfur and iron. The CR analysis showed that the thickness of the scale layer was identified and quantified with accuracy. These results can help in the decision making about removing the deposited scale.

  18. Detection of fissionable materials in cargoes using monochromatic photon radiography

    NASA Astrophysics Data System (ADS)

    Danagoulian, Areg; Lanza, Richard; O'Day, Buckley; LNSP Team

    2015-04-01

    The detection of Special Nuclear Materials (e.g. Pu and U) and nuclear devices in the commercial cargo traffic is one of the challenges posed by the threat of nuclear terrorism. Radiography and active interrogation of heavily loaded cargoes require ~ 1 - 10MeV photons for penetration. In a proof-of-concept system under development at MIT, the interrogating monochromatic photon beam is produced via a 11B(d , nγ) 12C reaction. To achieve this, a boron target is used along with the 3 MeV d+ RFQ accelerator at MIT-Bates. The reactions results in the emission of very narrow 4.4 MeV and 15.1 MeV gammas lines. The photons, after traversing the cargo, are detected by an array of NaI(Tl) detectors. A spectral analysis of the transmitted gammas allows to independently determine the areal density and the atomic number (Z) of the cargo. The proposed approach could revolutionize cargo inspection, which, in its current fielded form has to rely on simple but high dose bremsstrahlung sources. Use of monochromatic sources would significantly reduce the necessary dose and allow for better determination of the cargo's atomic number. The general methodology will be described and the preliminary results from the proof-of-concept system will be presented and discussed. Supported by NSF/DNDO Collaborative Research ARI-LA Award ECCS-1348328.

  19. Micro-radiography of biological samples with medical contrast agents

    NASA Astrophysics Data System (ADS)

    Dammer, J.; Weyda, F.; Benes, J.; Sopko, V.; Gelbic, I.

    2013-12-01

    Micro-radiography is an imaging technique that uses X-rays to study the internal structures of objects. This fast and easy imaging tool is based on differential X-ray attenuation by various tissues and structures within biological samples. The experimental setup described is based on the semiconductor pixel X-ray detector Medipix2 and X-ray micro-focus tube. Our micro-radiographic system has been recently used not only for the examination of internal structures of various arthropods and other biological objects but also for tracing some processes in selected model species (we used living larvae of mosquito Culex quinquefasciatus). Low concentrations of iodine, lanthanum or gold particles were used as a tracer (contrast agent). Such contrast agents increase the absorption of X-rays and allow a better visibility of internal structures of model organisms (especially the various cavities, pores, etc.). In addition, the movement of tracers in selected timing experiments demonstrates some physiological functions of digestive and excretory system.

  20. Dual, orthogonal, backlit pinhole radiography in OMEGA experiments

    SciTech Connect

    Kuranz, C. C.; Blue, B. E.; Drake, R. P.; Robey, H. F.; Hansen, J. F.; Knauer, J. P.; Grosskopf, M. J.; Krauland, C.; Marion, D. C.

    2006-10-15

    Backlit pinhole radiography used with ungated film as a detector creates x-ray radiographs with increased resolution and contrast. Current hydrodynamics experiments on the OMEGA Laser use a three-dimensional sinusoidal pattern as a seed perturbation for the study of instabilities. The structure of this perturbation makes it highly desirable to obtain two simultaneous orthogonal backlighting views. We accomplished this using two backlit pinholes each mounted 12 mm from the target. The pinholes, of varying size and shape, were centered on 5 mm square foils of 50 {mu}m thick Ta. The backlighting is by K-alpha emission from a 500 {mu}m square Ti or Sc foil mounted 500 {mu}m from the Ta on a plastic substrate. Four laser beams overfill the metal foil, so that the expanding plastic provides radial tamping of the expanding metal plasma. The resulting x-rays pass through the target onto (ungated) direct exposure film (DEF). Interference between the two views is reduced by using a nose cone in front of the DEF, typically with a 9 mm Ta aperture and with magnets to deflect electrons. Comparison of varying types of pinholes and film exposures will be presented from recent experiments as well as an analysis of the background noise created using this experimental technique.

  1. Modeling and measurement of root canal using stereo digital radiography

    NASA Astrophysics Data System (ADS)

    Analoui, Mostafa; Krisnamurthy, Satthya; Brown, Cecil

    2000-04-01

    Determining root canal length is a crucial step in success of root canal treatment. Root canal length is commonly estimated based on pre-operation intraoral radiography. 2D depiction of a 3D object is the primary source of error in this approach. Techniques based on impedance measurement are more accurate than radiographic approaches, but do not offer a method for depicting the shape of canal. In this study, we investigated a stererotactic approach for modeling and measurement of root canal of human dentition. A weakly perspective model approximated the projectional geometry. A series of computer-simulated objects was used to test accuracy of this model as the first step. The, to assess the clinical viability of such an approach, endodontic files inserted in the root canal phantoms were fixed on an adjustable platform between a radiographic cone and an image receptor. Parameters of projection matrix were computed based on the relative positions of image receptors, focal spot, and test objects. Rotating the specimen platform from 0 to 980 degrees at 5-degree intervals set relative angulations for stereo images. Root canal is defined as the intersection of two surfaces defined by each projection. Computation of error for length measurement indicates that for angulations greater than 40 degrees the error is within clinically acceptable ranges.

  2. Dynamic and static error analyses of neutron radiography testing

    SciTech Connect

    Joo, H.; Glickstein, S.S.

    1999-03-01

    Neutron radiography systems are being used for real-time visualization of the dynamic behavior as well as time-averaged measurements of spatial vapor fraction distributions for two phase fluids. The data in the form of video images are typically recorded on videotape at 30 frames per second. Image analysis of he video pictures is used to extract time-dependent or time-averaged data. The determination of the average vapor fraction requires averaging of the logarithm of time-dependent intensity measurements of the neutron beam (gray scale distribution of the image) that passes through the fluid. This could be significantly different than averaging the intensity of the transmitted beam and then taking the logarithm of that term. This difference is termed the dynamic error (error in the time-averaged vapor fractions due to the inherent time-dependence of the measured data) and is separate from the static error (statistical sampling uncertainty). Detailed analyses of both sources of errors are discussed.

  3. Proton Radiography of Shape Charge Jets Penetrating Teflon and Explosive

    NASA Astrophysics Data System (ADS)

    Ferm, Eric N.; Burkett, Michael W.; Hull, Larry M.; Marr-Lyon, Mark; McNeil, Wendy V.; Morris, Chris L.; Rightley, Paul M.; Lansce Proton Radiography Team

    2011-06-01

    We have used proton radiography at the Los Alamos Neutron Science Center to observe viper shaped charge jets penetrating inert and explosive materials. A viper jet was observed penetrating both Teflon and PBX 9501. Radiographs captured the penetration events at several times and are analyzed to determine the density of the materials imaged at each time. The interfaces and shock waves in the flow are clearly evident in the images. Multiple time images allow the determination of the velocities of the interfaces and shock waves. Comparisons are made in the Teflon case with estimates of penetration rates and densities using the quasi-steady approximation analysis used in many terminal ballistics models. The PBX 9501 clearly detonated from the impact of the shape charge jet tip traveling at 9.1 mm/s. The detonation wave is examined to see what support it obtains from the pursing jet and the jet is examined to find the influence of the explosive products on penetration velocity. This experiment gives us experimental results of in-situ penetration process that can be used to verify common modeling techniques and fluid mechanic calculations of the penetration process.

  4. Using polychromatic X-radiography to examine realistic imitation firearms.

    PubMed

    Austin, J C; Day, C R; Kearon, A T; Valussi, S; Haycock, P W

    2008-10-25

    Sections 36-41 of the Violent Crimes Reduction Act (2006), which came into force in England and Wales on 1st October 2007, have placed significant restrictions on the sale and possession of 'realistic imitation firearms'. This legislation attempts to produce a definition of a 'realistic imitation' which clearly differentiates these items from other imitation firearms (which are not covered by the legislation). This paper will go a stage further by demonstrating techniques by which blank firing realistic imitation firearms which may be suitable for illegal conversion to fire live rounds may be differentiated from other less 'suitable' (but visually identical) realistic imitations. The article reports on the use of X-radiography, utilizing the bremsstrahlung of a commercial broad spectrum X-ray source, to identify the differences between alloys constituting the barrels of distinct replica and/or blank firing handguns. The resulting pseudo-signatures are transmission spectra over a range from 20 to 75 kV, taken at 1 kV intervals, which are extracted from stacks of registered, field flattened images. It is shown that it is possible to quantify differences between transmission spectra for components of different realistic imitation fire arms, and apply the results to determine the suitability of particular gun barrels from blank firing imitation firearms for illegal conversion to fire live rounds, or related illegal modifications. PMID:18842365

  5. Time-resolved fast-neutron radiography of air-water two-phase flows in a rectangular channel by an improved detection system

    SciTech Connect

    Zboray, Robert; Dangendorf, Volker; Bromberger, Benjamin; Tittelmeier, Kai; Mor, Ilan

    2015-07-15

    In a previous work, we have demonstrated the feasibility of high-frame-rate, fast-neutron radiography of generic air-water two-phase flows in a 1.5 cm thick, rectangular flow channel. The experiments have been carried out at the high-intensity, white-beam facility of the Physikalisch-Technische Bundesanstalt, Germany, using an multi-frame, time-resolved detector developed for fast neutron resonance radiography. The results were however not fully optimal and therefore we have decided to modify the detector and optimize it for the given application, which is described in the present work. Furthermore, we managed to improve the image post-processing methodology and the noise suppression. Using the tailored detector and the improved post-processing, significant increase in the image quality and an order of magnitude lower exposure times, down to 3.33 ms, have been achieved with minimized motion artifacts. Similar to the previous study, different two-phase flow regimes such as bubbly slug and churn flows have been examined. The enhanced imaging quality enables an improved prediction of two-phase flow parameters like the instantaneous volumetric gas fraction, bubble size, and bubble velocities. Instantaneous velocity fields around the gas enclosures can also be more robustly predicted using optical flow methods as previously.

  6. Time-resolved fast-neutron radiography of air-water two-phase flows in a rectangular channel by an improved detection system

    NASA Astrophysics Data System (ADS)

    Zboray, Robert; Dangendorf, Volker; Mor, Ilan; Bromberger, Benjamin; Tittelmeier, Kai

    2015-07-01

    In a previous work, we have demonstrated the feasibility of high-frame-rate, fast-neutron radiography of generic air-water two-phase flows in a 1.5 cm thick, rectangular flow channel. The experiments have been carried out at the high-intensity, white-beam facility of the Physikalisch-Technische Bundesanstalt, Germany, using an multi-frame, time-resolved detector developed for fast neutron resonance radiography. The results were however not fully optimal and therefore we have decided to modify the detector and optimize it for the given application, which is described in the present work. Furthermore, we managed to improve the image post-processing methodology and the noise suppression. Using the tailored detector and the improved post-processing, significant increase in the image quality and an order of magnitude lower exposure times, down to 3.33 ms, have been achieved with minimized motion artifacts. Similar to the previous study, different two-phase flow regimes such as bubbly slug and churn flows have been examined. The enhanced imaging quality enables an improved prediction of two-phase flow parameters like the instantaneous volumetric gas fraction, bubble size, and bubble velocities. Instantaneous velocity fields around the gas enclosures can also be more robustly predicted using optical flow methods as previously.

  7. Time-resolved fast-neutron radiography of air-water two-phase flows in a rectangular channel by an improved detection system.

    PubMed

    Zboray, Robert; Dangendorf, Volker; Mor, Ilan; Bromberger, Benjamin; Tittelmeier, Kai

    2015-07-01

    In a previous work, we have demonstrated the feasibility of high-frame-rate, fast-neutron radiography of generic air-water two-phase flows in a 1.5 cm thick, rectangular flow channel. The experiments have been carried out at the high-intensity, white-beam facility of the Physikalisch-Technische Bundesanstalt, Germany, using an multi-frame, time-resolved detector developed for fast neutron resonance radiography. The results were however not fully optimal and therefore we have decided to modify the detector and optimize it for the given application, which is described in the present work. Furthermore, we managed to improve the image post-processing methodology and the noise suppression. Using the tailored detector and the improved post-processing, significant increase in the image quality and an order of magnitude lower exposure times, down to 3.33 ms, have been achieved with minimized motion artifacts. Similar to the previous study, different two-phase flow regimes such as bubbly slug and churn flows have been examined. The enhanced imaging quality enables an improved prediction of two-phase flow parameters like the instantaneous volumetric gas fraction, bubble size, and bubble velocities. Instantaneous velocity fields around the gas enclosures can also be more robustly predicted using optical flow methods as previously. PMID:26233413

  8. Accuracy of Digital Bitewing Radiography versus Different Views of Digital Panoramic Radiography for Detection of Proximal Caries

    PubMed Central

    Abdinian, Mehrdad; Razavi, Sayed Mohammad; Samety, Amir Abbas; Faghihian, Elham

    2015-01-01

    Objectives: Dental caries are common and have a high incidence among populations. Radiographs are essential for detecting proximal caries. The best technique should be recognized for accurate detection of caries. The aim of this study was to compare the accuracy of detection of proximal caries using intraoral bitewing, extraoral bitewing, improved interproximal panoramic, improved orthogonality panoramic and conventional panoramic radiographs. Materials and Methods: In this descriptive cross sectional study, 100 extracted human teeth with and without proximal caries were used. Intra and extraoral radiographs were taken. Images were evaluated and scored by two observers. Scores were compared with the histological gold standard. The diagnostic accuracy of radiographs was assessed by means of receiver operating characteristic (ROC) curve analysis (P<0.05). Results: Microscopic evaluation of proximal surfaces revealed that 54.8% of the surfaces were sound and 45.2% were carious (with different depths). The differences in the area under the ROC curve (Az value) among the five techniques were not statistically significant. Conclusion: Improved interproximal panoramic and extraoral bitewing radiographs were superior to conventional panoramic radiography for detection of proximal caries ex vivo and should be considered for patients with contraindications for intraoral radiographs. PMID:26622284

  9. An advanced image processing method to improve the spatial resolution of ion radiographies.

    PubMed

    Krah, N; Testa, M; Brons, S; Jäkel, O; Parodi, K; Voss, B; Rinaldi, I

    2015-11-01

    We present an optimization method to improve the spatial resolution and the water equivalent thickness (WET) accuracy of ion radiographies. The method is designed for imaging systems measuring for each actively scanned beam spot the lateral position of the pencil beam and at the same time the Bragg curve (behind the target) in discrete steps without relying on tracker detectors to determine the ion trajectory before and after the irradiated volume. Specifically, the method was used for an imaging set-up consisting of a stack of 61 parallel-plate ionization chambers (PPIC) interleaved with absorber plates of polymethyl methacrylate (PMMA) working as a range telescope. The method uses not only the Bragg peak position, but approximates the entire measured Bragg curve as a superposition of differently shifted Bragg curves. Their relative weights allow to reconstruct the distribution of thickness around each scan spot of a heterogeneous phantom. The approach also allows merging the ion radiography with the geometric information of a co-registered x-ray radiography in order to increase its spatial resolution. The method was tested using Monte Carlo simulated and experimental proton radiographies of a PMMA step phantom and an anthropomorphic head phantom. For the step phantom, the effective spatial resolution was found to be 6 and 4 times higher than the nominal resolution for the simulated and experimental radiographies, respectively. For the head phantom, a gamma index was calculated to quantify the conformity of the simulated proton radiographies with a digitally reconstructed radiography (DRR) obtained from an x-ray CT and properly converted into WET. For a distance-to-agreement (DTA) of 2.5 mm and a relative WET difference (RWET) of 2.5%, the passing ratio was 100%/85% for the optimized/non-optimized case, respectively. When the optimized proton radiography was merged with the co-registered DRR, the passing ratio was 100% at DTA  =  1.3 mm and RWET

  10. Variation in emergency department use of cervical spine radiography for alert, stable trauma patients

    PubMed Central

    Stiell, I G; Wells, G A; Vandemheen, K; Laupacis, A; Brison, R; Eisenhauer, M A; Greenberg, G H; MacPhail, I; McKnight, R D; Reardon, M; Verbeek, R; Worthington, J; Lesiuk, H

    1997-01-01

    OBJECTIVE: To, assess the emergency department use of cervical spine radiography for alert, stable adult trauma patients in terms of utilization, yield for injury and variation in practices among hospitals and physicians. DESIGN: Retrospective survey of health records. SETTING: Emergency departments of 6 teaching and 2 community hospitals in Ontario and British Columbia. PATIENTS: Consecutive alert, stable adult trauma patients seen with potential cervical spine injury between July 1, 1994, and June 30, 1995. MAIN OUTCOME MEASURES: Total number of eligible patients, referral for cervical spine radiography (overall, by hospital and by physician), presence of cervical spine injury, patient characteristics and hospitals associated with use of radiography. RESULTS: Of 6855 eligible patients, cervical spine radiography was ordered for 3979 (58.0%). Only 60 (0.9%) patients were found to have an acute cervical spine injury (fracture, dislocation or ligamentous instability); 98.5% of the radiographic films were negative for any significant abnormality. The demographic and clinical characteristics of the patients were similar across the 8 hospitals, and no cervical spine injuries were missed. Significant variation was found among the 8 hospitals in the rate of ordering radiography (p < 0.0001), from a low of 37.0% to a high of 72.5%. After possible differences in case severity and patient characteristics at each hospital were controlled for, logistic regression analysis revealed that 6 of the hospitals were significantly associated with the use of radiography. At 7 hospitals, there was significant variation in the rate of ordering radiography among the attending emergency physicians (p < 0.05), from a low of 15.6% to a high of 91.5%. CONCLUSIONS: Despite considerable variation among institutions and individual physicians in the ordering of cervical spine radiography for alert, stable trauma patients with similar characteristics, no cervical spine injuries were missed. The

  11. An advanced image processing method to improve the spatial resolution of ion radiographies

    NASA Astrophysics Data System (ADS)

    Krah, N.; Testa, M.; Brons, S.; Jäkel, O.; Parodi, K.; Voss, B.; Rinaldi, I.

    2015-11-01

    We present an optimization method to improve the spatial resolution and the water equivalent thickness (WET) accuracy of ion radiographies. The method is designed for imaging systems measuring for each actively scanned beam spot the lateral position of the pencil beam and at the same time the Bragg curve (behind the target) in discrete steps without relying on tracker detectors to determine the ion trajectory before and after the irradiated volume. Specifically, the method was used for an imaging set-up consisting of a stack of 61 parallel-plate ionization chambers (PPIC) interleaved with absorber plates of polymethyl methacrylate (PMMA) working as a range telescope. The method uses not only the Bragg peak position, but approximates the entire measured Bragg curve as a superposition of differently shifted Bragg curves. Their relative weights allow to reconstruct the distribution of thickness around each scan spot of a heterogeneous phantom. The approach also allows merging the ion radiography with the geometric information of a co-registered x-ray radiography in order to increase its spatial resolution. The method was tested using Monte Carlo simulated and experimental proton radiographies of a PMMA step phantom and an anthropomorphic head phantom. For the step phantom, the effective spatial resolution was found to be 6 and 4 times higher than the nominal resolution for the simulated and experimental radiographies, respectively. For the head phantom, a gamma index was calculated to quantify the conformity of the simulated proton radiographies with a digitally reconstructed radiography (DRR) obtained from an x-ray CT and properly converted into WET. For a distance-to-agreement (DTA) of 2.5 mm and a relative WET difference (RWET) of 2.5%, the passing ratio was 100%/85% for the optimized/non-optimized case, respectively. When the optimized proton radiography was merged with the co-registered DRR, the passing ratio was 100% at DTA  =  1.3 mm and RWET

  12. An evaluation of author productivity in international radiography journals 2004–2011

    SciTech Connect

    Snaith, Beverly A

    2013-09-15

    Radiography, the allied health profession, has changed beyond recognition over the last century; however, in academic terms radiography is a relatively young profession. It is therefore still establishing its professional knowledge base. This article uses peer-review author productivity distribution to evaluate its scholarly maturity. Four peer-reviewed journals in medical radiation sciences were examined over an 8-year period (2004–2011) and author productivity was compared to Lotka's law. Further analysis of the most prolific authors provided an evaluation of their characteristics. The 1306 unique authors contributed 835 articles during the study period. Of these, 1012 (77.5%) contributed only one article to the journals studied, with an inverse power relationship of author productivity. At the 0.1 level of significance, radiography does not fit Lotka's law (n = −2.334; c = 0.712; D{sub max} = 0.0627; Critical threshold = 0.0337). There was a significant correlation between the most prolific authors and collaboration (P = 0.002), although variation was noted in author discipline and location. The results of this study add to the discussion of radiography scholarship and demonstrate that the radiography authors have similar productivity distribution to other professions, but do not follow Lotka's law.

  13. Obstructive sleep apnea in preschool-aged Japanese children - efficiency of screening using lateral neck radiography.

    PubMed

    Kitamura, Takuro; Miyazaki, Soichiro; Kobayashi, Ryuichi; Kadotani, Hiroshi; Kanemura, Takashi; Komada, Ichiro; Nishikawa, Michiko; Okawa, Masako; Koizumi, Hiroki; Takeuchi, Shoko; Suzuki, Hideaki

    2016-06-01

    Conclusions The prevalence of obstructive sleep apnea (OSA) in preschool-aged children diagnosed by the International Classification of Sleep Disorders (ICSD) version 3 criteria was relatively higher than that diagnosed by ICSD-2. Although the assessment of the upper airway by lateral neck radiography was effective for detecting OSA in this age group, this assessment is not recommended for all children as a screening method because of parental concern related to radiation exposure. Objective This study investigated the prevalence of OSA and the screening capacity of lateral neck radiography in community-based preschool-aged children. Methods Parents of 211 children aged 3-6 years were requested to complete the sleep-related questionnaire. Subjects who agreed to further investigations were invited to undergo home type 3 portable monitoring and clinical examination, including radiography. We estimated the prevalence of OSA and evaluated the detection power of radiography for predicting OSA. Results One hundred and eighty-eight (89.1%) subjects completed the questionnaire and 67 (31.8%) agreed to further examinations. The weighted prevalence was 7.3% and 12.8% by ICSD-2 and 3, respectively. Area under the receiver operator curve for the adenoidal/nasopharyngeal and tonsil/pharyngeal ratios measured using radiography was slightly larger than that for tonsil size graded by visual inspection. PMID:26901288

  14. Use of ultrasound, color Doppler imaging and radiography to monitor periapical healing after endodontic surgery.

    PubMed

    Tikku, Aseem P; Kumar, Sunil; Loomba, Kapil; Chandra, Anil; Verma, Promila; Aggarwal, Renu

    2010-09-01

    This study evaluated the effectiveness of ultrasound, color Doppler imaging and conventional radiography in monitoring the post-surgical healing of periapical lesions of endodontic origin. Fifteen patients who underwent periapical surgery for endodontic pathology were randomly selected. In all patients, periapical lesions were evaluated preoperatively using ultrasound, color Doppler imaging and conventional radiography, to analyze characteristics such as size, shape and dimensions. On radiographic evaluation, dimensions were measured in the superoinferior and mesiodistal direction using image-analysis software. Ultrasound evaluation was used to measure the changes in shape and dimensions on the anteroposterior, superoinferior, and mesiodistal planes. Color Doppler imaging was used to detect the blood-flow velocity. Postoperative healing was monitored in all patients at 1 week and 6 months by using ultrasound and color Doppler imaging, together with conventional radiography. The findings were then analyzed to evaluate the effectiveness of the 3 imaging techniques. At 6 months, ultrasound and color Doppler imaging were significantly better than conventional radiography in detecting changes in the healing of hard tissue at the surgical site (P < 0.004). This study demonstrates that ultrasound and color Doppler imaging have the potential to supplement conventional radiography in monitoring the post-surgical healing of periapical lesions of endodontic origin. PMID:20881334

  15. General Dental Practitioners’ Concept towards Using Radiography and Apex-Locators in Endodontics

    PubMed Central

    Raoof, Maryam; Heidaripour, Maryam; Shahravan, Arash; Haghani, Jahangir; Afkham, Arash; Razifar, Mahsa; Mohammadizadeh, Sakineh

    2014-01-01

    Introduction: Despite being the gold standard as well as a routine technique in endodontics, radiographic working length (WL) determination owns many drawbacks. Electronic apex-locators (EALs) are recommended to complement radiographies. The aim of this study was to evaluate the perceptions of Iranian general dental practitioners (GDPs) towards using radiography and EAL. Methods and Materials: Three hundred and ninety one GDPs attending the 53th Iranian Dental Association Congress completed a questionnaire focusing on the use of radiography and EALs during the various stages of root canal treatment. The data was analyzed with the chi-square test with the level of significance set at 0.05. The results were then calculated as frequencies and percentages. Results: More than half of the GDPs reported using radiographs as the sole method for WL determination. A total of 30.4% of the practitioners were using the combined approach during root canal therapy of a single-rooted tooth, while 38.9% used this method in multi-rooted teeth. Approximately half of the respondents would not order follow-up radiographies after root canal treatment. Conclusion: Radiography continues to be the most common method for WL determination in Iran. PMID:25386209

  16. Inspection of Alpine glaciers with cosmic-ray muon radiography

    NASA Astrophysics Data System (ADS)

    Nishiyama, Ryuichi; Ariga, Akitaka; Ariga, Tomoko; Ereditato, Antonio; Lechmann, Alessandro; Mair, David; Scampoli, Paola; Schlunegger, Fritz; Vladymyrov, Mykhailo

    2016-04-01

    Radiography using cosmic-ray muons represents a challenging method for probing the bedrock topography beneath Alpine glaciers. We present the current status of our feasibility study at Eiger glacier, situated on the western flank of the Eiger in the Jungfrau region, Central Swiss Alps. The muon radiography is a technique that has been recently developed to investigate the internal density profiles of geoscientific targets. It is based on the measurement of the absorption of the cosmic-ray muons inside a material. Because the energy spectrum of cosmic-ray muons and the energy dependence of muon range have been studied well during the past years, the attenuation of the muon flux can be used to derive the column density, i.e. the density integrated along the muon trajectories, of geoscientific targets. This technique has recently been applied for non-invasive inspection of volcanoes, nuclear reactors, seismic faults, caves and etc. The greatest advantage of the method in the field of glacier studies is that it yields a unique solution of the density underneath a glacier without any assumption of physical properties inside the target. Large density contrasts, as expected between glacier ice (˜ 1.0g/cm3) and bedrock (˜ 2.5g/cm3), would allow us to elucidate the shape of the bedrock in high resolution. Accordingly, this technology will provide for the first time information on the bedrock surface beneath a steep and non-accessible Alpine glacier, in a complementary way with respect to other exploration methods (drilling, ground penetrating radar, seismic survey, gravity explorations and etc.). Our first aim is to demonstrate the feasibility of the method through a case study at the Eiger glacier, situated in the Central Swiss Alps. The Eiger glacier straddles the western flank of the Eiger between 3700 and 2300 m above sea level (a.s.l.). The glacier has shortened by about 150 m during the past 30 years in response to the ongoing global warming, causing a concern for

  17. Measurement and analysis of release isentropes using proton radiography (u)

    SciTech Connect

    Schwartz, Cynthia L; Rigg, Paulo A; Cherne, Frank J; Hixson, Rob S; Greff, Carl W

    2011-01-25

    Off-Hugoniot measurements are needed to further develop predictive models that accurately describe the behavior of metals undergoing phase transitions. Predictive modeling of phase transitions is essential for LANL to meet its programmatic objectives. Understanding the dynamic evolution of density as a function of time during the release process is important to developing high fidelity equation of state models. This is particularly true for metals that have a degree of complexity, such as a solid-solid phase transition. The equations-of-state (EOS) for metals with complexity are more difficult to measure and to model, and states far away from where measurements are easily made can be poorly known. Accurate density measurements can provide us with additional fundamental information that can be used to further constrain the equation of state for a material. Currently release isentrope information is obtained from shock experiments at a sample window interface using optical velocimetry. This data is highly convoluted due to wave interactions between the sample window-interface making it difficult to infer physical processes happening within the material. Proton radiography has the ability to probe the release waves in-situ before these wave interactions can take place. Since multiple radiographs are obtained in each experiment, pRad provides the unique capability of being able to measure both density and wave evolution within the material. The measurement of release wave densities, however, presents new challenges for pRad since the release wave of a shocked transition is not a step function but instead a ramped wave. Previous pRad experiments have generally measured density jumps over step transitions; therefore, new analysis techniques will have to be developed to measure the ramped density change of a release isentrope. Once developed, these new analysis techniques can also be used for experiments that involve ramped compression. This kind of compression is being

  18. Image processing in digital chest radiography: effect on diagnostic efficacy.

    PubMed

    Manninen, H; Partanen, K; Lehtovirta, J; Matsi, P; Soimakallio, S

    1992-01-01

    The usefulness of digital image processing of chest radiographs was evaluated in a clinical study. In 54 patients, chest radiographs in the posteroanterior projection were obtained by both 14 inch digital image intensifier equipment and the conventional screen-film technique. The digital radiographs (512 x 512 image format) viewed on a 625 line monitor were processed in three different ways: (1) standard display; (2) digital edge enhancement for the standard display; and (3) inverse intensity display. The radiographs were interpreted independently by three radiologists. The diagnoses were confirmed by CT, follow-up radiographs and clinical records. Chest abnormalities of the films analyzed included 21 primary lung tumors, 44 pulmonary nodules, 16 cases with mediastinal disease and 17 cases with pneumonia/atelectasis. Interstitial lung disease, pleural plaques, and pulmonary emphysema were found in 30, 18 and 19 cases, respectively. The sensitivity of conventional radiography when averaged overall findings was better than that of the digital techniques (P less than 0.001). The differences in diagnostic accuracy measured by sensitivity and specificity between the three digital display modes were small. Standard image display showed better sensitivity for pulmonary nodules (0.74 vs 0.66; P less than 0.05) but poorer specificity for pulmonary emphysema (0.85 vs. 0.93; P less than 0.05) compared with inverse intensity display. We conclude that when using 512 x 512 image format, the routine use of digital edge enhancement and tone reversal at digital chest radiographs is not warranted. PMID:1563421

  19. Digital fast neutron radiography of steel reinforcing bar in concrete

    NASA Astrophysics Data System (ADS)

    Mitton, K.; Jones, A.; Joyce, M. J.

    2014-12-01

    Neutron imaging has previously been used in order to test for cracks, degradation and water content in concrete. However, these techniques often fall short of alternative non-destructive testing methods, such as γ-ray and X-ray imaging, particularly in terms of resolution. Further, thermal neutron techniques can be compromised by the significant expense associated with thermal neutron sources of sufficient intensity to yield satisfactory results that can often precipitate the need for a reactor. Such embodiments are clearly not portable in the context of the needs of field applications. This paper summarises the results of a study to investigate the potential for transmission radiography based on fast neutrons. The objective of this study was to determine whether the presence of heterogeneities in concrete, such as reinforcement structures, could be identified on the basis of variation in transmitted fast-neutron flux. Monte-Carlo simulations have been performed and the results from these are compared to those arising from practical tests using a 252Cf source. The experimental data have been acquired using a digital pulse-shape discrimination system that enables fast neutron transmission to be studied across an array of liquid scintillators placed in close proximity to samples under test, and read out in real time. Whilst this study does not yield sufficient spatial resolution, a comparison of overall flux ratios does provide a basis for the discrimination between samples with contrasting rebar content. This approach offers the potential for non-destructive testing that gives less dose, better transportability and better accessibility than competing approaches. It is also suitable for thick samples where γ-ray and X-ray methods can be limited.

  20. Optimisation of computed radiography systems for chest imaging

    NASA Astrophysics Data System (ADS)

    Alzimami, K.; Sassi, S.; Alkhorayef, M.; Britten, A. J.; Spyrou, N. M.

    2009-03-01

    The main thrust of this study is to investigate methods of optimising the radiation dose-image quality relationship in computed radiography (CR) systems for chest imaging. Specifically, this study investigates the possibility of reducing the patient radiation exposure through an optimal selection of tube filtration, exposure parameters and air gap technique, in parallel with a study of the image quality, particularly low contrast detail detectability, signal-to-noise ratio (SNR) and scatter fraction (SF). The CDRAD phantom was used to assess the quality of the CR images. Tissue equivalent Polystyrene blocks were placed in the front of the phantom as scattering material with thicknesses of 5 and 15 cm to simulate an adult chest and heart/diaphragm regions, respectively. A series of exposure techniques were used, including Cu filtration with various thicknesses of Cu in the presence and absence of an air gap, whilst the exposure was kept as constant as possible throughout. The estimated patient effective dose and skin entrance dose were calculated using the NRPB-SR262 X-ray dose calculation software. The results have shown that the low contrast-detail detectability in the lung and the heart/diaphragm regions improves when using an air gap and no Cu filtration, particularly at low kilovoltage (kVp). However, there is no significant difference in low contrast-detail in the absence or presence of a 0.2 mm Cu filtration. SF values for the lung and heart regions decrease when using both, the air gap technique and a 0.2 mm Cu filtration, particularly at low kVp. SNR values for the lung and heart regions improve when using a small Cu thickness. In conclusion, this investigation has shown that the quality of chest CR images could be improved by using an air gap technique and a 0.2 mm Cu filtration at low kVp, particularly at 99 kVp.

  1. Analysis of sculptures using XRF and X-ray radiography

    NASA Astrophysics Data System (ADS)

    Calza, C.; Oliveira, D. F.; Freitas, R. P.; Rocha, H. S.; Nascimento, J. R.; Lopes, R. T.

    2015-11-01

    This work reports the analysis of two sacred images on polychrome wood using X-ray Radiography and Energy Dispersive X-Ray Fluorescence. The first case is the analysis of a sculpture portraying Saint Sebastian, the patron saint of Rio de Janeiro, which is considered the second most ancient sacred image of Brazil. This sculpture was made in Portugal and was transported to Brazil by Estácio Sá, founder of the city of Rio de Janeiro, in 1565. Nowadays, it is located on the main altar of the Church of Capuchin Friars. The second case is the analysis of a sculpture representing Our Lady of Conception, which is located in the D. João VI Museum (EBA/UFRJ, Rio de Janeiro). The objective of these analyses was to evaluate the general conditions of the sculptures, identifying possible problems and internal damages, areas that revealed signs of previous retouchings and the materials and pigments employed by the artists, in order to assist its restoration procedures. EDXRF measurements were carried out with a portable system, developed at the Nuclear Instrumentation Laboratory, consisting of a Si-PIN XR-100CR detector from Amptek and an Oxford TF3005 X-ray tube with W anode. An X-ray source, a CR System GE CR50P and IP detectors were used to perform the radiographs. The XRF analysis of the sculptures identified the original pigments in both cases and the radiographic images revealed details of the manufacture; restored regions; extensive use of lead white; presence of cracks on the wood; use of nails and spikes, etc.

  2. New detector for use in fast neutron radiography

    NASA Astrophysics Data System (ADS)

    Popov, V.; Degtiarenko, P.; Musatov, I.

    2011-01-01

    We have developed and tested a new detector for use in the fast neutron (FN) imaging radiography applications, which is distinct from other presently known FN imagers. Our device implements a neutron-sensitive scintillator attached to a position-sensitive photomultiplier tube, and operates in the event-by-event readout mode, acquiring energy, timing, and pulse shape information for all detected radiation events. This information is used to help separate events of FN interactions in the scintillator from the background events, caused by the electronics noise and by other types of background radiation. The detector performance for FN imaging application was tested using the D-D neutron generator, designed and manufactured by Adelphi Technology, Inc. This essentially point-like neutron source operates in continuous mode, producing up to 109 of 2.5 MeV neutrons per second. Samples made of metals, plastic, and other materials were used to measure the detector resolution, efficiency and uniformity. Results of these tests are presented and discussed. Both X and Y position resolutions of the FN imaging detector are estimated to be less than 0.5 mm (sigma). Because this detector shows the fraction-of-a-millimeter resolution desirable for most of FN applications, is capable of good neutron-background separation, and is built using radiation hard materials, we believe that it could be a good alternative to other FN imaging systems based on CCD or solid state detectors. In addition, because of its sub-nanosecond timing resolution, it is suitable for the time-of-flight energy-resolved FN imaging.

  3. Performance characteristics of a Kodak computed radiography system.

    PubMed

    Bradford, C D; Peppler, W W; Dobbins, J T

    1999-01-01

    The performance characteristics of a photostimulable phosphor based computed radiographic (CR) system were studied. The modulation transfer function (MTF), noise power spectra (NPS), and detective quantum efficiency (DQE) of the Kodak Digital Science computed radiography (CR) system (Eastman Kodak Co.-model 400) were measured and compared to previously published results of a Fuji based CR system (Philips Medical Systems-PCR model 7000). To maximize comparability, the same measurement techniques and analysis methods were used. The DQE at four exposure levels (30, 3, 0.3, 0.03 mR) and two plate types (standard and high resolution) were calculated from the NPS and MTF measurements. The NPS was determined from two-dimensional Fourier analysis of uniformly exposed plates. The presampling MTF was determined from the Fourier transform (FT) of the system's finely sampled line spread function (LSF) as produced by a narrow slit. A comparison of the slit type ("beveled edge" versus "straight edge") and its effect on the resulting MTF measurements was also performed. The results show that both systems are comparable in resolution performance. The noise power studies indicated a higher level of noise for the Kodak images (approximately 20% at the low exposure levels and 40%-70% at higher exposure levels). Within the clinically relevant exposure range (0.3-3 mR), the resulting DQE for the Kodak plates ranged between 20%-50% lower than for the corresponding Fuji plates. Measurements of the presampling MTF with the two slit types have shown that a correction factor can be applied to compensate for transmission through the relief edges. PMID:9949395

  4. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following...

  5. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following...

  6. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following...

  7. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following...

  8. 42 CFR Appendix G to Part 75 - Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography G Appendix G to Part 75 Public Health PUBLIC HEALTH SERVICE...—Standards for Licensing Dental Hygienists and Dental Assistants in Dental Radiography The following...

  9. Gamma-ray and neutron radiography as part of a pulsed fast neutron analysis inspection system

    NASA Astrophysics Data System (ADS)

    Rynes, J.; Bendahan, J.; Gozani, T.; Loveman, R.; Stevenson, J.; Bell, C.

    1999-02-01

    A gamma-ray and neutron radiography system has been developed to provide useful supplemental information for a Pulsed Fast Neutron Analysis (PFNA) cargo inspection system. PFNA uses a collimated beam of pulsed neutrons to interrogate cargoes using (n, γx) reactions. The PFNA source produces both gamma rays as well as neutrons. The transmission of both species through the cargo is measured with an array of plastic scintillators. Since the neutron and gamma-ray signals are easily separated by arrival time a separate image can be made for both species. The radiography measurement is taken simultaneously with the PFNA measurement turning PFNA into an emission and transmission imaging system, thus enhancing the PFNA radiography system.

  10. Changes in the Small Intestine of a Cat Associated with Barium Sulphate Following Contrast Radiography.

    PubMed

    Igarashi, H; Oishi, M; Ohno, K; Tsuboi, M; Irie, N; Uchida, K; Tsujimoto, H

    2016-01-01

    A 7-year-old neutered male domestic short-haired cat that had undergone contrast radiography of the bowel with barium sulphate after acute episodes of vomiting 2 months previously, was presented with chronic vomiting, anorexia and weight loss. Abdominal radiography and ultrasonography revealed residual contrast enhancement and an obstruction of the small intestine. A contracted and stenosed ileum and distal jejunum were identified by exploratory laparotomy and surgically resected; subsequently, the clinical signs resolved. Histopathological examination of the ileum revealed mucosal ulceration with severe submucosal granulation tissue formation associated with scattered foreign crystalline material. Energy-dispersive X-ray spectroscopy revealed that the crystals contained barium sulphate. This is the first report in animals of the rare complication of barium sulphate incorporation into the gastrointestinal mucosa after contrast radiography. PMID:26997652

  11. Searching early bone metastasis on plain radiography by using digital imaging processing

    NASA Astrophysics Data System (ADS)

    Jaramillo-Núñez, A.; Pérez-Meza, M.

    2012-10-01

    Some authors mention that it is not possible to detect early bone metastasis on plain radiography. In this work we use digital imaging processing to analyze three radiographs taken from a patient with bone metastasis discomfort on the right shoulder. The time period among the first and second radiography was approximately one month and between the first and the third one year. This procedure is a first approach in order to know if in this particular case it was possible to detect an early bone metastasis. The obtained results suggest that by carrying out a digital processing is possible to detect the metastasis since the radiography contains the information although visually it is not possible to observe it.

  12. [An introduction and implementation of problem-based learning for radiography positioning training].

    PubMed

    Terashita, Takayoshi; Ogasawara, Katsuhiko

    2015-03-01

    The knowledge of radiological technologists is expected to increase with medical development. However, it is impossible to impart all knowledge in a limited time frame. Problem-based learning (PBL) is a learning methodology to solve it. In the PBL, students can gain problem-solving abilities by acquiring necessary knowledge from clinical cases and applying them during practice. We here report to implement the PBL in radiography practice. This practice opened a course at 2nd semester of third-grade students in our school. The practice flow includes presentation of clinical case and a survey of necessary knowledge, group work, radiography, reflection through practice, and deliberation of different cases. The clinical case was the radiography of an emergency patient. The evaluation items were about knowledge, skill, and attitude. By the PBL practice, students could realize a clinical scene, and discover considerable points unwritten in textbooks. PMID:25797664

  13. Precision of Porosity Calculation from "Material Stopping Power" Using Neutron Radiography

    NASA Astrophysics Data System (ADS)

    Nshimirimana, Robert; Radebe, Mabuti; de Beer, Frikkie

    The ability of digital neutron radiography to determine several important physical properties (e.g. porosity) of porous media and to identify the location of constituencies inside the sample in a non-destructive manner, are of great important in the fields of nuclear waste encapsulation and -shielding, civil engineering and geological studies. Unfortunately material thickness and radiation scatter hamper the accuracy and precision ofmeasurements. Correction methods are used to minimize the effect of neutron scattering in quantitative analysis neutron radiography experiment. To further minimize the error due to neutron scattering, it is advisable to position the sample as far away as possible from the neutron detector when perform quantitative neutron radiography. That requires the trade between sharpness and neutron scattering. In this work the neutron radiographyquantitative experiments were performed when the samples are placed too close (≈ 0.1 cm) to the detector; and accurate results of porosity measurement were obtained without applying any neutron scattering correction tool or method.

  14. High Resolution Neutron Radiography and Tomography of Hydrided Zircaloy-4 Cladding Materials

    SciTech Connect

    Smith, Tyler S; Bilheux, Hassina Z; Ray, Holly B; Bilheux, Jean-Christophe; Yan, Yong

    2015-01-01

    Neutron radiography for hydrogen analysis was performed with several Zircaloy-4 cladding samples with controlled hydrogen concentrations up to 1100 ppm. Hydrogen charging was performed in a process tube that was heated to facilitate hydrogen absorption by the metal. A correlation between the hydrogen concentration in the hydrided tubes and the neutron intensity was established, by which hydrogen content can be determined precisely in a small area (55 m x 55 m). Radiography analysis was also performed to evaluate the heating rate and its correlation with the hydrogen distribution through hydrided materials. In addition to radiography analysis, tomography experiments were performed on Zircaloy-4 tube samples to study the local hydrogen distribution. Through tomography analysis a 3D reconstruction of the tube was evaluated in which an uneven hydrogen distribution in the circumferential direction can be observed.

  15. Evaluation of exposure parameters in plain radiography: a comparative study with European guidelines.

    PubMed

    Lança, L; Silva, A; Alves, E; Serranheira, F; Correia, M

    2008-01-01

    Typical distribution of exposure parameters in plain radiography is unknown in Portugal. This study aims to identify exposure parameters that are being used in plain radiography in the Lisbon area and to compare the collected data with European references [Commission of European Communities (CEC) guidelines]. The results show that in four examinations (skull, chest, lumbar spine and pelvis), there is a strong tendency of using exposure times above the European recommendation. The X-ray tube potential values (in kV) are below the recommended values from CEC guidelines. This study shows that at a local level (Lisbon region), radiographic practice does not comply with CEC guidelines concerning exposure techniques. Further national/local studies are recommended with the objective to improve exposure optimisation and technical procedures in plain radiography. This study also suggests the need to establish national/local diagnostic reference levels and to proceed to effective measurements for exposure optimisation. PMID:18430717

  16. The integral dose in panoramic intraoral x-ray tube radiography

    SciTech Connect

    Hayami, A.; Fujishita, M.; Sumida, A.; Kanke, M.; Fujiki, T.; Uemura, S.; Fuchihata, H.

    1983-07-01

    A Monte Carlo computer program was developed to estimate the integral dose to the head and thyroid for panoramic intraoral x-ray tube radiography. The advantage of this computer simulation is that it is able to avoid many of the difficulties associated with low-energy and low-dose x-ray dosimetry. The calculations were made for maxillary and mandibular projections separately, using 10 kv. increments between 40 and 60 kv. The results obtained were presented in terms of the integral dose per milliampere second. Typical integral doses for a routine examination of the head are 2.1 mJ. and 8.5 microJ for the thyroid during mandibular radiography and 1.7 microJ for the thyroid during radiography of the maxilla using 55 kv. and 0.5 mAs.

  17. Action research in radiography: What it is and how it can be conducted

    PubMed Central

    Munn, Zachary; Pearson, Alan; Jordan, Zoe; Murphy, Frederick; Pilkington, Diana

    2013-01-01

    Action research is a form of research that investigates and describes a social or work situation with the aim of achieving a change which results in improvement. This article emphasizes the potential for action research to be a useful research method in radiography. A search was conducted to determine the extent to which action research has been utilized in radiography. Although action research has been used in a number of health-care settings, there are no published examples of action research being utilized in a clinical medical imaging department. Action research is discussed in detail, along with an example guide for an action research study. Action research has been identified as a useful way to affect change, to involve radiographers in the research process, and to introduce evidence-based practice to radiography. PMID:26229607

  18. Semi-Monochromatic Plasma Flash Radiography and Its Application to Biomedical Imaging Simulation

    NASA Astrophysics Data System (ADS)

    Takahashi, Kei; Sato, Eiichi; Sagae, Michiaki; Tsukahara, Yasuo

    1998-07-01

    A high-intensity plasma flash X-ray generator having a radiation tube with a rod-shaped target and its application to biomedical imaging simulations are described. Plasma flash radiography was performed with charged voltages of 40, 50, and 60 kV, and with filter of the same material as the target. In the present work, molybdenum target was employed. With filter of the half value layer in thickness for each target, nearly monochromatic radiography with only K-characteristic X-ray spectra could be achieved. Next, with real X-ray spectra data acquired from the present generator, we performed a computer-aided biomedical imaging simulation using the program SPECTRA. It was developed as an assisting tool for our fundamental research on optimum control of flash X-ray spectra. Qualitatively, the simulated biomedical phantom images agreed with those from the Computed Radiography.

  19. Breadboard Facility

    NASA Technical Reports Server (NTRS)

    1977-01-01

    In the sixties, Chrysler was NASA's prime contractor for the Saturn I and IB test launch vehicles. The company installed and operated at Huntsville what was known as the Saturn I/IB Development Breadboard Facility. "Breadboard," means an array of electrical and electronic equipment for performing a variety of development and test functions. This work gave Chrysler a broad capability in computerized testing to assure quality control in development of solid-state electronic systems. Today that division is manufacturing many products not destined for NASA, most of them being associated with the company's automotive line. A major project is production and quality-control testing of the "lean-burn" engine, one that has a built-in Computer to control emission timing, and allow the engine to run on a leaner mixture of fuel and air. Other environment-related products include vehicle emission analyzers. The newest of the line is an accurate, portable solid state instrument for testing auto exhaust gases. The exhaust analyzers, now being produced for company dealers and for service

  20. Status of the Dual Axis Radiographic Hydrodynamics Test (DARHT) Facility

    NASA Astrophysics Data System (ADS)

    Burns, Michael J.; Caporaso, George J.; Carlsten, Bruce E.; Chen, Yu-Jiuan; Chow, Ken P.; Cook, Edward G.; Davis, Harold A.; Ekdahl, Carl A.; Fawley, William M.; Fortgang, Clifford M.; Hughes, Thomas P.; McCuistian, B. R. Trent; Nielsen, Kurt E.; Rutkowski, Henry L.; Sampayan, Steve; Waldron, Will L.; Watson, James A.; Westenskow, Glenn A.; Yu, Simon S.

    2002-12-01

    The Dual-Axis Radiographic Hydrodynamics Test (DARHT) facility will employ two perpendicular electron Linear Induction Accelerators to produce intense, bremsstrahlung x-ray pulses for flash radiography. We intend to produce measurements containing three-dimensional information with sub-millimeter spatial resolution of the interior features of very dense, explosively-driven objects. The facility will be completed in two phases with the first phase having become operational in July 1999 utilizing a single-pulse, 20-MeV, 2-kA, 60-ns accelerator, a high-resolution electro-optical x-ray imaging system, and other hydrodynamics testing systems. We will briefly describe this machine. The first electron beams will be generated in the second phase of DARHT this year. The second DARHT accelerator consists of a 18.4-MeV, 2-kA, 2-microsecond pulse-width accelerator. Four short electron micropulses of variable pulse-width and spacing will be chopped out of the original, long accelerator pulse for producing time-resolved x-ray images. The second phase also features an extended, high-resolution electro-optical x-ray system with a framing speed of about 2-MHz. We will discuss this accelerator by summarizing the overall design of the long-pulse injector and accelerator. We will also discuss the fast kicker used to separate the long-pulse beam into short bursts suitable for radiography.

  1. Combined x-ray scattering, radiography, and velocity interferometry/streaked optical pyrometry measurements of warm dense carbon using a novel technique of shock-and-release

    SciTech Connect

    Falk, K.; Collins, L. A.; Kagan, G.; Kress, J. D.; Montgomery, D. S.; Srinivasan, B.; Gamboa, E. J.; Tzeferacos, P.; Benage, J. F.

    2014-05-15

    This work focused on a new application of the shock-and-release technique for equation of state (EOS) measurements. Warm dense matter states at near normal solid density and at temperatures close to 10 eV in diamond and graphite samples were created using a deep release from a laser-driven shock at the OMEGA laser facility. Independent temperature, density, and pressure measurements that do not depend on any theoretical models or simulations were obtained using imaging x-ray Thomson scattering, radiography, velocity interferometry, and streaked optical pyrometry. The experimental results were reproduced by the 2-D FLASH radiation hydrodynamics simulations finding a good agreement. The final EOS measurement was then compared with widely used SESAME EOS models as well as quantum molecular dynamics simulation results for carbon, which were very consistent with the experimental data.

  2. Design and initial 1D radiography tests of the FANTOM mobile fast-neutron radiography and tomography system

    NASA Astrophysics Data System (ADS)

    Andersson, P.; Valldor-Blücher, J.; Andersson Sundén, E.; Sjöstrand, H.; Jacobsson-Svärd, S.

    2014-08-01

    The FANTOM system is a tabletop sized fast-neutron radiography and tomography system newly developed at the Applied Nuclear Physics Division of Uppsala University. The main purpose of the system is to provide time-averaged steam-and-water distribution measurement capability inside the metallic structures of two-phase test loops for light water reactor thermal-hydraulic studies using a portable fusion neutron generator. The FANTOM system provides a set of 1D neutron transmission data, which may be inserted into tomographic reconstruction algorithms to achieve a 2D mapping of the steam-and-water distribution. In this paper, the selected design of FANTOM is described and motivated. The detector concept is based on plastic scintillator elements, separated for spatial resolution. Analysis of pulse heights on an event-to-event basis is used for energy discrimination. Although the concept allows for close stacking of a large number of detector elements, this demonstrator is equipped with only three elements in the detector and one additional element for monitoring the yield from the neutron generator. The first measured projections on test objects of known configurations are presented. These were collected using a Sodern Genie 16 neutron generator with an isotropic yield of about 1E8 neutrons per second, and allowed for characterization of the instrument's capabilities. At an energy threshold of 10 MeV, the detector offered a count rate of about 500 cps per detector element. The performance in terms of spatial resolution was validated by fitting a Gaussian Line Spread Function to the experimental data, a procedure that revealed a spatial unsharpness in good agreement with the predicted FWHM of 0.5 mm.

  3. Monte Carlo simulation optimisation of zinc sulphide based fast-neutron detector for radiography using a 252Cf source

    NASA Astrophysics Data System (ADS)

    Meshkian, Mohsen

    2016-02-01

    Neutron radiography is rapidly extending as one of the methods for non-destructive screening of materials. There are various parameters to be studied for optimising imaging screens and image quality for different fast-neutron radiography systems. Herein, a Geant4 Monte Carlo simulation is employed to evaluate the response of a fast-neutron radiography system using a 252Cf neutron source. The neutron radiography system is comprised of a moderator as the neutron-to-proton converter with suspended silver-activated zinc sulphide (ZnS(Ag)) as the phosphor material. The neutron-induced protons deposit energy in the phosphor which consequently emits scintillation light. Further, radiographs are obtained by simulating the overall radiography system including source and sample. Two different standard samples are used to evaluate the quality of the radiographs.

  4. Proton radiography of PBX 9502 detonation shock dynamics confinement sandwich test

    SciTech Connect

    Aslam, Tariq D; Jackson, Scott I; Morris, John S

    2009-01-01

    Recent results utilizing proton radiography (P-Rad) during the detonation of the high explosive PBX 9502 are presented. Specifically, the effects of confinement of the detonation are examined in the LANL detonation confinement sandwich geometry. The resulting detonation velocity and detonation shock shape are measured. In addition, proton radiography allows one to image the reflected shocks through the detonation products. Comparisons are made with detonation shock dynamics (DSD) and reactive flow models for the lead detonation shock and detonation velocity. In addition, predictions of reflected shocks are made with the reactive flow models.

  5. Optimum angle-cut of collimator for dense objects in high-energy proton radiography

    NASA Astrophysics Data System (ADS)

    Hai-Bo, Xu; Na, Zheng

    2016-02-01

    The use of minus identity lenses with an angle-cut collimator can achieve high contrast images in high-energy proton radiography. This article presents the principles of choosing the angle-cut aperture of the collimator for different energies and objects. Numerical simulation using the Monte Carlo code Geant4 has been implemented to investigate the entire radiography for the French test object. The optimum angle-cut apertures of the collimators are also obtained for different energies. Supported by NSAF (11176001) and Science and Technology Developing Foundation of China Academy of Engineering Physics (2012A0202006)

  6. X-ray backscatter imaging for radiography by selective detection and snapshot: Evolution, development, and optimization

    NASA Astrophysics Data System (ADS)

    Shedlock, Daniel

    Compton backscatter imaging (CBI) is a single-sided imaging technique that uses the penetrating power of radiation and unique interaction properties of radiation with matter to image subsurface features. CBI has a variety of applications that include non-destructive interrogation, medical imaging, security and military applications. Radiography by selective detection (RSD), lateral migration radiography (LMR) and shadow aperture backscatter radiography (SABR) are different CBI techniques that are being optimized and developed. Radiography by selective detection (RSD) is a pencil beam Compton backscatter imaging technique that falls between highly collimated and uncollimated techniques. Radiography by selective detection uses a combination of single- and multiple-scatter photons from a projected area below a collimation plane to generate an image. As a result, the image has a combination of first- and multiple-scatter components. RSD techniques offer greater subsurface resolution than uncollimated techniques, at speeds at least an order of magnitude faster than highly collimated techniques. RSD scanning systems have evolved from a prototype into near market-ready scanning devices for use in a variety of single-sided imaging applications. The design has changed to incorporate state-of-the-art detectors and electronics optimized for backscatter imaging with an emphasis on versatility, efficiency and speed. The RSD system has become more stable, about 4 times faster, and 60% lighter while maintaining or improving image quality and contrast over the past 3 years. A new snapshot backscatter radiography (SBR) CBI technique, shadow aperture backscatter radiography (SABR), has been developed from concept and proof-of-principle to a functional laboratory prototype. SABR radiography uses digital detection media and shaded aperture configurations to generate near-surface Compton backscatter images without scanning, similar to how transmission radiographs are taken. Finally, a

  7. A Selenium-Based Detector System For Digital Slot-Radiography

    NASA Astrophysics Data System (ADS)

    Hillen, W.; Schiebel, U.; Zaengel, T.

    1988-06-01

    A research system for digital radiography is described, which is based on a selenium detector with capacitive probe readout. The detector, in which a selenium drum is used as the primary image receptor, is exposed by a scanning fan beam. Scatter reduction and primary transmission by slot-radiography as well as the imaging properties of the selenium detector are discussed. The spatial resolution and the noise behaviour of the detector are analysed. The signal-to-noise ratios expressed in terms of noise equivalent quanta and detective quantum efficiency are calculated and compared with competitive systems.

  8. Muon radiography in Russia with emulsion technique. First experiments future perspectives

    SciTech Connect

    Aleksandrov, A. B.; Bagulya, A. V.; Chernyavsky, M. M.; Konovalova, N. S.; Polukhina, N. G.; Shchedrina, T. V.; Starkov, N. I.; Tioukov, V. E.; Vladymyrov, M. S.; Managadze, A. K.; Roganova, T. M.; Orurk, O. I.; Zemskova, S. G.

    2015-12-31

    Cosmic ray muon radiography is a novel technique for imaging the internal structures of massive objects. It exploits the capability of high energy muons from cosmic-rays in order to obtain a density map of investigated object and trying to guess information on the variation in the density distribution. Nuclear emulsions are tracking detectors well suited to be employed in this context since they have an excellent angular resolution (few mrad), they are cheap, compact and robust, easily transportable, able to work in harsh environments, and do not require power supply. This work presents the first successful results in the field of muon radiography in Russia with nuclear emulsions.

  9. Application of neutron radiography to visualization of cryogenic fluid boiling two-phase flows

    NASA Astrophysics Data System (ADS)

    Takenaka, Nobuyuki; Asano, Hitoshi; Fujii, Terushige; Ushiro, Toshihiko; Iwatani, Junji; Murata, Yutaka; Mochiki, Koh-ichi; Taguchi, Akira; Matsubayashi, Masahito; Tsuruno, Akira

    1996-02-01

    Liquid nitrogen boiling two-phase flows in a metallic container and in a heat exchanger were visualized by real-time thermal neutron radiography at JRR-3M at the Japan Atomic Energy Research Institute and image processed by the Musashi dynamic image processing system. Boiling phenomena in a pool and boiling two-phase flow in an aluminum plate fin type heat exchanger were visualized. It was shown that neutron radiography was applicable to visualization of cryogenic boiling two-phase flow and the designs of cryogenic heat exchangers.

  10. Advantages of a 400 speed image receptor system for cast radiography.

    PubMed

    Gratale, P; Burns, C B; Murray, J

    1987-01-01

    By using a faster intensifying screen as opposed to the traditional extremity system for cast radiography, one can reduce the dose to the patient significantly while maintaining quality cast radiographs. In this study a 400 speed Lanex Regular, TMG film system was compared to a 100 speed Lanex Fine, TMG film system. The findings suggest that slow speed, high resolution systems are unnecessary for cast radiography. Evidence demonstrated reduced patient exposure and suggested decreased motion and increased tube life as a result of shorter exposures. PMID:3588882

  11. Planning and cost analysis of digital radiography services for a network of hospitals (the Veterans Integrated Service Network).

    PubMed

    Duerinckx, A J; Kenagy, J J; Grant, E G

    1998-01-01

    This study analysed the design and cost of a picture archiving and communications system (PACS), computerized radiography (CR) and a wide-area network for teleradiology. The Desert Pacific Healthcare Network comprises 10 facilities, including four tertiary medical centres and one small hospital. Data were collected on radiologists' workloads, and patient and image flow within and between these medical centres. These were used to estimate the size and cash flows associated with a system-wide implementation of PACS, CR and teleradiology services. A cost analysis model was used to estimate the potential cost savings in a filmless radiology environment. ATM technology was selected as the communications medium between the medical centres. A strategic plan and business plan were successfully developed. The cost model predicted the cost-effectiveness of the proposed PACS/CR configuration within four to six years, if the base costs were kept low. The experience gained in design and cost analysis of a PACS/teleradiology network will serve as a model for similar projects. PMID:10321046

  12. The First Pulsed-Power Z-Pinch Liner-On-Target Hydrodynamics Experiment Diagnosed with Proton Radiography

    NASA Astrophysics Data System (ADS)

    Rousculp, C. L.; Reass, W. A.; Oro, D. M.; Griego, J. R.; Turchi, P. J.; Reinovsky, R. E.; Saunders, A.; Mariam, F. G.; Morris, C.

    2014-10-01

    The first pulse-power driven, dynamic, liner-on-target experiment was successfully conducted at the Los Alamos proton radiography (pRad) facility. 100% data return was achieved on this experiment including a 21-image pRad movie. The experiment was driven with the PHELIX pulsed-power machine that utilizes a high-efficiency (k ~ 0.93) transformer to couple a small capacitor bank (U ~ 300 kJ) to a low inductance condensed-matter experimental load in a Z-pinch configuration. The current pulse (Ipeak = 3.7 MA, δt ~10 μs) was measured via a fiber optic Faraday rotation diagnostic. The experimental load consisted of a cylindrical Al liner (6 cm diam, 3 cm tall, 0.8 mm thick) and a cylindrical Al target (3 cm diam, 3 cm tall, 0.1 mm thick) that was coated with a thin (0.1 mm) uniform layer of tungsten powder (1 micron diam). It is observed that the shock-launched powder layer fully detaches from the target into a spatially correlated, radially converging (vr ~ 800 m/s) ring. The powder distribution is highly modulated in azimuth indicating particle interactions are significant. Results are compared to MHD simulations. Work supported by United States-DOE under Contract DE-AC52-06NA25396.

  13. Analysis of radial radiography for the liner stability series at Pegasus: PGII-59, PGII-62, and PGII-63

    SciTech Connect

    Morgan, D.V.; Platts, D.; Shlachter, J.S.; Martinez, D.L.; Carpenter, B.

    1997-09-01

    Recently, three liner stability experiments were performed at the Pegasus II pulsed power facility to determine the asymmetric variations in the material density of a cylindrical liner during an electro-magnetically driven implosion. The initial campaign consisted of three experiments, designated LS-1, LS-2, and LS-3. LS-1 and LS-2 were driven with a peak current of approximately 4.2 MA, whereas the peak current for LS-3 was approximately 6.4 MA. All three liners initially were 0.4 mm wall aluminum cylinders with a mean radius of 2.38 cm and a height of 2.0 cm. The inner surface of each liner was coated with a thin (18--23 {micro}m) layer of gold to aid in the determination of the position of the inner surface of the liner. Radial radiography was used to characterize the z-dependent and {theta}-dependent instabilities that were observed as the liner contracted.

  14. Update on the Hot Fuel Examination Facility (HFEF) complex

    SciTech Connect

    Bacca, J.P.

    1985-01-01

    The Hot Fuel Examination Facility (HFEF) Complex continues to provide primary postirradiation handling and examination support for the US, US/Japanese, and US/United Kingdom Liquid Metal Fast Breeder Reactor (LMFBR) fuels and materials development and reactor safety programs. For the last several years, such support has also been provided for other US nuclear programs. These include the Light Water Reactor Safety Program, the Three Mile Island No. 2 (TMI-2) reactor accident-recovery programs, the Light Water Breeder Reactor Program, the US Air Force Neutron Radiography Program, and Defense Nuclear Programs. The HFEF facilities have been refurbished and upgraded and capabilities have been added to accommodate these programs and to maintain the HFEF Complex as a world-class, state-of-the-art hot-cell complex.

  15. Waste Examination Assay Facility operations: TRU waste certification

    SciTech Connect

    Schultz, F.J.; Caylor, B.A.; Coffey, D.E.; Phoenix, L.B.

    1987-01-01

    The ORNL Waste Examination Assay Facility (WEAF) was established to nondestructively assay (NDA) transuranic (TRU) waste generated at Oak Ridge National Laboratory (ORNL). The present facility charter encompasses the NDA and nondestructive examination (NDE) of both TRU and low-level wastes (LLW). Presently, equipment includes a Neutron Assay System (NAS), a Segmented Gamma Scanner (SGS), a drum-sized Real-Time Radiography (RTR) system, and a Neutron Slab Detector (NSD). The first three instruments are computer interfaced. Approximately 2300 TRU waste drums have been assayed with the NAS and the SGS. Another 3000 TRU and LLW drums have been examined with the RTR unit. Computer data bases have been developed to collate the large amount of data generated during the assays and examinations. 6 refs., 1 tab.

  16. Gamma-ray and neutron radiography for a pulsed fast- neutron analysis cargo inspection system

    NASA Astrophysics Data System (ADS)

    Rynes, Joel Christian

    1999-11-01

    This dissertation presents the design, optimization, and characterization of a gamma-ray and neutron radiographic subsystem that was developed for the Pulsed Fast Neutron Analysis (PFNA) cargo inspection system. The PFNA inspection system uses nanosecond pulsed neutrons to produce three-dimensional elemental density images of cargo. Contraband in the cargo can be detected by its elemental content. The PFNA neutron source produces gamma rays as well as neutrons. The radiographic subsystem measures these radiations in an array of plastic scintillators to produce gamma-ray and neutron transmission images of the cargo simultaneously with the PFNA measurement. Although the radiographic subsystem improves PFNA performance in many forms of contraband detection, it was specifically designed to detect Special Nuclear Material (SNM) in cargo containers and trucks. A feasibility study, including experiments and modeling, was performed to determine the usefulness of gamma-ray radiography in this application. The study assumed a baseline configuration of the PFNA source, a relatively small rectangular radiation beam, and a plastic detector with a 5.1 cm diameter and a 7.6 cm length. The study showed that the baseline configuration was useful in cargoes up to 144 g/cm2 thick. At this thickness, a signal-to-noise ratio of three was obtainable per pixel. The maximum cargo thickness was later increased to 180 g/cm2 by increasing the detector length to 17.0 cm and by changing the source beam stop from gold to copper. An experiment was then performed that determined a 3.5 cm radiographic resolution was adequate for SNM detection. The detector configuration and the source motion were optimized to obtain a resolution of approximately 3.5 cm using the minimal number of detectors and the maximum detector diameter. The source is moved up and down as the cargo is pulled through the system to irradiate the entire surface of the cargo with the radiation beam. The final design consisted of

  17. Pencil beam proton radiography using a multilayer ionization chamber.

    PubMed

    Farace, Paolo; Righetto, Roberto; Meijers, Arturs

    2016-06-01

    A pencil beam proton radiography (PR) method, using a commercial multilayer ionization chamber (MLIC) integrated with a treatment planning system (TPS) was developed. A Giraffe (IBA Dosimetry) MLIC (±0.5 mm accuracy) was used to obtain pencil beam PR by delivering spots uniformly positioned at a 5.0 mm distance in a 9  ×  9 square of spots. PRs of an electron-density (with tissue-equivalent inserts) phantom and a head phantom were acquired. The integral depth dose (IDD) curves of the delivered spots were computed by the TPS in a volume of water simulating the MLIC, and virtually added to the CT at the exit side of the phantoms. For each spot, measured and calculated IDD were overlapped in order to compute a map of range errors. On the head-phantom, the maximum dose from PR acquisition was estimated. Additionally, on the head phantom the impact on the range errors map was estimated in case of a 1 mm position misalignment. In the electron-density phantom, range errors were within 1 mm in the soft-tissue rods, but greater in the dense-rod. In the head-phantom the range errors were  -0.9  ±  2.7 mm on the whole map and within 1 mm in the brain area. On both phantoms greater errors were observed at inhomogeneity interfaces, due to sensitivity to small misalignment, and inaccurate TPS dose computation. The effect of the 1 mm misalignment was clearly visible on the range error map and produced an increased spread of range errors (-1.0  ±  3.8 mm on the whole map). The dose to the patient for such PR acquisitions would be acceptable as the maximum dose to the head phantom was  <2cGyE. By the described 2D method, allowing to discriminate misalignments, range verification can be performed in selected areas to implement an in vivo quality assurance program. PMID:27164479

  18. Pencil beam proton radiography using a multilayer ionization chamber

    NASA Astrophysics Data System (ADS)

    Farace, Paolo; Righetto, Roberto; Meijers, Arturs

    2016-06-01

    A pencil beam proton radiography (PR) method, using a commercial multilayer ionization chamber (MLIC) integrated with a treatment planning system (TPS) was developed. A Giraffe (IBA Dosimetry) MLIC (±0.5 mm accuracy) was used to obtain pencil beam PR by delivering spots uniformly positioned at a 5.0 mm distance in a 9  ×  9 square of spots. PRs of an electron-density (with tissue-equivalent inserts) phantom and a head phantom were acquired. The integral depth dose (IDD) curves of the delivered spots were computed by the TPS in a volume of water simulating the MLIC, and virtually added to the CT at the exit side of the phantoms. For each spot, measured and calculated IDD were overlapped in order to compute a map of range errors. On the head-phantom, the maximum dose from PR acquisition was estimated. Additionally, on the head phantom the impact on the range errors map was estimated in case of a 1 mm position misalignment. In the electron-density phantom, range errors were within 1 mm in the soft-tissue rods, but greater in the dense-rod. In the head-phantom the range errors were  ‑0.9  ±  2.7 mm on the whole map and within 1 mm in the brain area. On both phantoms greater errors were observed at inhomogeneity interfaces, due to sensitivity to small misalignment, and inaccurate TPS dose computation. The effect of the 1 mm misalignment was clearly visible on the range error map and produced an increased spread of range errors (‑1.0  ±  3.8 mm on the whole map). The dose to the patient for such PR acquisitions would be acceptable as the maximum dose to the head phantom was  <2cGyE. By the described 2D method, allowing to discriminate misalignments, range verification can be performed in selected areas to implement an in vivo quality assurance program.

  19. Shielding effect of thyroid collar for digital panoramic radiography

    PubMed Central

    Han, G-S; Cheng, J-G; Li, G

    2013-01-01

    Objectives: To evaluate the shielding effect of thyroid collar for digital panoramic radiography. Methods: 4 machines [Orthopantomograph® OP200 (Instrumentarium Dental, Tuusula, Finland), Orthophos CD (Sirona Dental Systems GmbH, Bensheim, Germany), Orthophos XG Plus (Sirona Dental Systems GmbH) and ProMax® (Planmeca Oy, Helsinki, Finland)] were used in this study. Average tissue-absorbed doses were measured using thermoluminescent dosemeter chips in an anthropomorphic phantom. Effective organ and total effective doses were derived according to the International Commission of Radiological Protection 2007 recommendations. The shielding effect of one collar in front and two collars both in front and at the back of the neck was measured. Results: The effective organ doses of the thyroid gland obtained from the 4 panoramic machines were 1.12 μSv for OP200, 2.71 μSv for Orthophos CD, 2.18 μSv for Orthophos XG plus and 2.20 μSv for ProMax, when no thyroid collar was used. When 1 collar was used in front of the neck, the effective organ doses of the thyroid gland were 1.01 μSv (9.8% reduction), 2.45 μSv (9.6% reduction), 1.76 μSv (19.3% reduction) and 1.70 μSv (22.7% reduction), respectively. Significant differences in dose reduction were found for Orthophos XG Plus and ProMax. When two collars were used, the effective organ doses of the thyroid gland were also significantly reduced for the two machines Orthophos XG Plus and ProMax. The same trend was observed in the total effective doses for the four machines. Conclusions: Wearing a thyroid collar was helpful when the direct digital panoramic imaging systems were in use, whereas for the indirect digital panoramic imaging systems, the thyroid collar did not have an extra protective effect on the thyroid gland and whole body. PMID:24005060

  20. R2 REGULATED FACILITIES

    EPA Science Inventory

    The Facility Registry System (FRS) is a centrally managed database that identifies facilities, sites or places subject to environmental regulations or of environmental interest. FRS creates high-quality, accurate, and authoritative facility identification records through rigorous...