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Sample records for proton radiography comparisons

  1. Proton nuclear scattering radiography

    International Nuclear Information System (INIS)

    Duchazeaubeneix, J.C.; Faivre, J.C.; Garreta, D.

    1982-10-01

    Nuclear scattering of protons allows to radiograph objects with specific properties: direct 3- dimensional radiography, different information as compared to X-ray technique, hydrogen radiography. Furthermore, it is a well adapted method to gating techniques allowing the radiography of fast periodic moving systems. Results obtained on different objects (light and heavy materials) are shown and discussed. The dose delivery is compatible with clinical use, but at the moment, the irradiation time is too long between 1 and 4 hours. Perspectives to make the radiography faster and to get a practical method are discussed

  2. Proton nuclear scattering radiography

    International Nuclear Information System (INIS)

    Saudinos, J.

    1982-04-01

    Nuclear scattering of protons allows to radiograph objects with specific properties: 3-dimensional radiography, different information as compared to X-ray technique, hydrogen radiography. Furthermore the nuclear scattering radiography (NSR) is a well adapted method to gating techniques allowing the radiography of fast periodic moving objects. Results obtained on phantoms, formalin fixed head and moving object are shown and discussed. The dose delivery is compatible with clinical use, but at the moment, the irradiation time is too long between 1 and 4 hours. Perspectives to make the radiograph faster and to get a practical method are discussed

  3. Apparatus for proton radiography

    International Nuclear Information System (INIS)

    Martin, R.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. 10 claims, 7 drawing figures

  4. Application of proton radiography to medical imaging

    International Nuclear Information System (INIS)

    Kramer, S.L.; Martin, R.L.; Moffett, D.R.; Colton, E.

    1977-12-01

    The use of charged particles for radiographic applications has been considered for some time, but progress has been impeded by the cost and availability of suitable accelerators. However, recent developments in technology could overcome these problems. A review is presented of the physical principles leading to an improvement in mass resolution per unit of absorbed dose for charged particle radiography relative to x-ray radiography. The quantitative comparisons between x-ray and proton radiographs presented here confirm this advantage. The implications of proton radiography on cancer detection, as well as future plans for developing a proton tomographic system, are discussed

  5. Proton Radiography (pRad)

    Data.gov (United States)

    Federal Laboratory Consortium — The proton radiography project has used 800 MeV protons provided by the LANSCE accelerator facility at LANL, to diagnose more than 300 dynamic experiments in support...

  6. Theoretical and experimental comparison of proton and helium-beam radiography using silicon pixel detectors

    Science.gov (United States)

    Gehrke, T.; Amato, C.; Berke, S.; Martišíková, M.

    2018-02-01

    Ion-beam radiography (iRAD) could potentially improve the quality control of ion-beam therapy. The main advantage of iRAD is the possibility to directly measure the integrated stopping power. Until now there is no clinical implementation of iRAD. Topics of ongoing research include developing dedicated detection systems to achieve the desired spatial resolution (SR) and investigating different ion types as imaging radiation. This work focuses on the theoretical and experimental comparison of proton (pRAD) and helium-beam radiography (αRAD). The experimental comparison was performed with an in-house developed detection system consisting of silicon pixel detectors. This system enables the measurement of energy deposition of single ions, their tracking, and the identification of the ion type, which is important for αRAD due to secondary fragments. A 161 mm-thick PMMA phantom with an air gap of 1 mm placed at different depths was imaged with a 168 MeV u-1 proton/helium-ion beam at the Heidelberg ion-beam therapy center. The image quality in terms of SR and contrast-to-noise ratio (CNR) was evaluated. After validating MC simulations against experiments, pRAD and αRAD were compared to carbon-beam radiography (cRAD) in simulations. The theoretical prediction that the CNR of pRAD and αRAD is equal at similar imaging doses was experimentally confirmed. The measured SR of αRAD was 55% better compared to pRAD. The simulated cRads showed the expected improvement in SR and the decreased CNR at the same dose compared to the αRads, however only at dose levels exceeding typical doses of diagnostic x-ray projections. For clinically applicable dose levels, the cRads suffered from an insufficient number of carbon ions per pixel (220 μm  ×  220 μm). In conclusion, it was theoretically and experimentally shown that αRAD provides a better SR than pRAD without any disadvantages concerning the CNR. Using carbon ions instead of helium ions leads to a better SR at the

  7. Proton Radiography at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-28

    The proton radiography (pRad) facility at Los Alamos National Lab uses high energy protons to acquire multiple frame flash radiographic sequences at megahertz speeds: that is, it can make movies of the inside of explosions as they happen. The facility is primarily used to study the damage to and failure of metals subjected to the shock forces of high explosives as well as to study the detonation of the explosives themselves. Applications include improving our understanding of the underlying physical processes that drive the performance of the nuclear weapons in the United States stockpile and developing novel armor technologies in collaboration with the Army Research Lab. The principle and techniques of pRad will be described, and examples of some recent results will be shown.

  8. Proton radiography using highpower femtosecond laser

    International Nuclear Information System (INIS)

    Choi, Chang Il

    2010-08-01

    A femtosecond laser emits pulses whose width is between few and few hundreds femtoseconds (10 -15 s). The production mechanism of the high energy protons generated by the femtosecond laser is not clear so far, but the technologies have been improving. The applications using the generated protons are the proton therapy, proton radiography, nuclear physics, security inspection, and so on. Especially in the radiography, the laser-generated protons are very useful to obtain high quality images of thin objects, because protons are able to penetrate an object following an almost straight path and give a depth distribution information of various elements in a subject. Since the laser-driven protons require lower cost and smaller facility than accelerator-based protons, the radiography using laser-driven protons have been of interest. In this research, we have performed the radiography experiments by using protons generated by the 100 TW titanium sapphire femtosecond laser facility of Advanced Photonics Research Institute (APRI) of Gwangju Institute of Science Technology (GIST). A CR-39 Solid State Nuclear Track Detector (SSNTD) has been used as radiography screen. The radiography digital images have been obtained by using an optical microscope and a CCD camera. Modulation Transfer Function (MTF) has been derived from analyzing the obtained images, and the spatial resolution of the images have been evaluated. And, we have performed the radiography experiments of monoenergetic proton from the Tandem Van de Graaff accelerator of Korea Institute of Geoscience and Mineral Resources (KIGAM). We have obtained and compared the radiography images from other proton production methods which are the laser and the accelerator, respectively. And also, we have found out the optimized chemical etching condition, in order to improve the spatial resolution of the radiography images. Finally, the evaluated maximum spatial resolution of the images are 2.09 μm

  9. Proton radiography to improve proton therapy treatment

    NARCIS (Netherlands)

    Takatsu, J.; van der Graaf, E. R.; van Goethem, Marc-Jan; van Beuzekom, M.; Klaver, T.; Visser, Jan; Brandenburg, S.; Biegun, A. K.

    The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT)

  10. Proton Radiography for the Diagnostics of a Dense Plasma

    Science.gov (United States)

    Barminova, H. Y.

    2017-12-01

    The possibility of using high-energy proton radiography for dense plasma diagnostics is discussed. The designed telescopic ion optical system for a proton radiography installation with a 1 GeV beam is presented. The schematic diagram of the proton microscope is given. It is shown that the estimate of spatial resolution for the installation obtained with consideration of chromatic aberrations of magnetic quadrupole lenses is limited from below.

  11. Magnifying lens for 800 MeV proton radiography

    International Nuclear Information System (INIS)

    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.

    2011-01-01

    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.

  12. Proton radiography of magnetic field in laser produced plasma

    International Nuclear Information System (INIS)

    Le Pape, S.; Patel, P.; Chen, S.; Town, R.; Mackinnon, A.

    2009-01-01

    Electromagnetic fields generated by the interaction with plasmas of long-pulse laser beams relevant to inertial confinement fusion have been measure. A proton beam generated by the interaction of an ultra intense laser with a thin metallic foil is used to probe the B-fields. The proton beam then generated is temporally short (of the order of a ps), highly laminar and hence equivalent to a virtual point which makes it an ideal source for radiography. We have investigated, using face-on radiography, B fields at intensity around 10 14 W/cm 2 due to the non co-linearity of temperature and density gradients. (authors)

  13. Pencil beam proton radiography using a multilayer ionization chamber

    NARCIS (Netherlands)

    Farace, Paolo; Righetto, Roberto; Meijers, Arturs

    2016-01-01

    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

  14. From 2D to 3D: Proton Radiography and Proton CT in proton therapy: A simulation study

    NARCIS (Netherlands)

    Takatsu, J.; van der Graaf, E.R.; van Goethem, M.-J.; Brandenburg, S.; Biegun, Aleksandra

    (1) Purpose In order to reduce the uncertainty in translation of the X-ray Computed Tomography (CT) image into a map of proton stopping powers (3-4% and even up to 10% in regions containing bones [1-8]), proton radiography is being studied as an alternative imaging technique in proton therapy. We

  15. Registration of pencil beam proton radiography data with X-ray CT.

    Science.gov (United States)

    Deffet, Sylvain; Macq, Benoît; Righetto, Roberto; Vander Stappen, François; Farace, Paolo

    2017-10-01

    Proton radiography seems to be a promising tool for assessing the quality of the stopping power computation in proton therapy. However, range error maps obtained on the basis of proton radiographs are very sensitive to small misalignment between the planning CT and the proton radiography acquisitions. In order to be able to mitigate misalignment in postprocessing, the authors implemented a fast method for registration between pencil proton radiography data obtained with a multilayer ionization chamber (MLIC) and an X-ray CT acquired on a head phantom. The registration was performed by optimizing a cost function which performs a comparison between the acquired data and simulated integral depth-dose curves. Two methodologies were considered, one based on dual orthogonal projections and the other one on a single projection. For each methodology, the robustness of the registration algorithm with respect to three confounding factors (measurement noise, CT calibration errors, and spot spacing) was investigated by testing the accuracy of the method through simulations based on a CT scan of a head phantom. The present registration method showed robust convergence towards the optimal solution. For the level of measurement noise and the uncertainty in the stopping power computation expected in proton radiography using a MLIC, the accuracy appeared to be better than 0.3° for angles and 0.3 mm for translations by use of the appropriate cost function. The spot spacing analysis showed that a spacing larger than the 5 mm used by other authors for the investigation of a MLIC for proton radiography led to results with absolute accuracy better than 0.3° for angles and 1 mm for translations when orthogonal proton radiographs were fed into the algorithm. In the case of a single projection, 6 mm was the largest spot spacing presenting an acceptable registration accuracy. For registration of proton radiography data with X-ray CT, the use of a direct ray-tracing algorithm to compute

  16. Review of medical radiography and tomography with proton beams

    Science.gov (United States)

    Johnson, Robert P.

    2018-01-01

    The use of hadron beams, especially proton beams, in cancer radiotherapy has expanded rapidly in the past two decades. To fully realize the advantages of hadron therapy over traditional x-ray and gamma-ray therapy requires accurate positioning of the Bragg peak throughout the tumor being treated. A half century ago, suggestions had already been made to use protons themselves to develop images of tumors and surrounding tissue, to be used for treatment planning. The recent global expansion of hadron therapy, coupled with modern advances in computation and particle detection, has led several collaborations around the world to develop prototype detector systems and associated reconstruction codes for proton computed tomography (pCT), as well as more simple proton radiography, with the ultimate intent to use such systems in clinical treatment planning and verification. Recent imaging results of phantoms in hospital proton beams are encouraging, but many technical and programmatic challenges remain to be overcome before pCT scanners will be introduced into clinics. This review introduces hadron therapy and the perceived advantages of pCT and proton radiography for treatment planning, reviews its historical development, and discusses the physics related to proton imaging, the associated experimental and computation issues, the technologies used to attack the problem, contemporary efforts in detector and computational development, and the current status and outlook.

  17. Medium range energy proton nuclear scattering radiography

    International Nuclear Information System (INIS)

    Duchazeaubeneix, J.C.

    1982-02-01

    This thesis is concerned with a new application of the strong nuclear interaction aiming to radiographic analysis. In this work, some physical processes have been analyzed with detail; these processes play a fundamental role in method quality and limitations; they have been detailed to facilitate comprehension to scientists who are not nuclear physicists. To better appreciate specific qualities of the RDN (Radiography par Diffusion Nucleaire), a chapter reviews strong nuclear interaction properties. Then, the experimental device is described, processing and acquisition system. Spatial resolution and sensitivity limits are studied. Results are presented [fr

  18. High-energy test of proton radiography concepts

    International Nuclear Information System (INIS)

    Amann, J.F.; Atencio, L.G.; Espinoza, C.J.

    1997-01-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this work was to demonstrate the use of high energy protons to produce radiographs of heavy metal test objects. The authors executed a proof-of-principle experiment using GeV proton beams available at the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS). The experiment produced proton radiographs of a suitably dense, unclassified test object. The experiment tested capabilities in data collection, image reconstruction, and hydro-code simulation and validated models of high-energy proton radiography. A lens was designed using existing quadrupole magnets, constructed on the A1 beam line of the AGS and used to image 10-GeV protons. The results include: (1) images made with an integrating detector, (2) measurements of the background and measurements of the resolution functions, and (3) forward model fits to the transmission data. In all cases the results agree with initial estimates and provide strong support for the utility of proton radiography as a new hydrotest diagnostic

  19. PROTON RADIOGRAPHY WITH THE PIXEL DETECTOR TIMEPIX

    Directory of Open Access Journals (Sweden)

    Václav Olšanský

    2016-12-01

    Full Text Available This article presents the processing of radiographic data acquired using the position-sensitive hybrid semiconductor pixel detector Timepix. Measurements were made on thin samples at the medical ion-synchrotron HIT [1] in Heidelberg (Germany with a 221 MeV proton beam. The charge is energy by the particles crossing the sample is registered for generation of image contrast. Experimental data from the detector were processed for derivation of the energy loss of each proton using calibration matrices. The interaction point of the protons on the detector were determined with subpixel resolution by model fitting of the individual signals in the pixelated matrix. Three methods were used for calculation of these coordinates: Hough transformation, 2D Gaussian fitting and estimate the 2D mean. Parameters of calculation accuracy and calculation time are compared for each method. The final image was created by method with best parameters.

  20. Proton Radiography: Cross Section Measurements and Detector Development

    International Nuclear Information System (INIS)

    Longo, Michael J.

    2003-01-01

    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

  1. Proton Radiography: Cross Section Measurement and Detector Development

    International Nuclear Information System (INIS)

    Longo, Michael J.

    2007-01-01

    Proton radiography offers significant advantages over conventional X-ray radiography, including the capability of looking into thick, dense materials, better contrast for a wide range of materials, sensitivity to different materials of similar density, and better resolution because of the ability to focus beams. In order to achieve this capability it is crucial to understand the background due to neutrons and photons and to develop techniques to reduce it to tolerable levels. 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 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 calorimeters. These are the only detectors in the experiment that provide information on neutrons and photons. We are taking a leading role in obtaining and analyzing the for-ward production data and in developing an optimal detector for proton radiography. With the support of our Stewardship Science Academic Alliances grant, we were able to design, build, and commission the calorimeters on budget and ahead of schedule. E-907 officially started physics running at Fermilab in January 2005, and data taking continued through February 2006. Data were taken on a range of targets, from liquid hydrogen to uranium, at beam energies from 5 GeV/c to 120 GeV/c. The analysis of the data is challenging because data from many different detector systems must be understood and merged and over 31 million events were accumulated. Our recent efforts have been devoted to the calibration of the neutron and photon detectors, to track and shower reconstruction, identification of forward-going neutrons, and simulation of the calorimeters in a Monte Carlo. Reconstruction of the data with improved tracking is underway

  2. Proton Radiography with CR-39 by Using the Protons from High Power Femto-second Laser System

    International Nuclear Information System (INIS)

    Choi, Chang Il; Lee, Dong Hoon; Kang, Byoung Hwi; Kim, Yong Kyun; Choi, Il Woo; Ko, Do Kyeong; Lee, Jong Min

    2008-01-01

    Proton radiography techniques are useful to obtain a high quality image of a thin object, because protons travel straight in matter. Generation of the high energy proton using conventional accelerator costs high and requires large accelerating facility. But proton radiography using high power femto-second(10-15 second) laser has been interested, because it can generate high energy protons at lower price than the conventional accelerator like a cyclotron. For this study, we used the CR-39 SSNTD (Solid State Nuclear Track Detector) as the proton radiography screen. Commonly, CR-39 is used to detect the tracks of energetic charged particles. Incident energetic charged particles left latent tracks in the CR-39, in the form of broken molecular chains and free radicals. These latent tracks show high chemical reactivity. After chemical etching with the caustic alkali solution such as NaOH or KOH, tracks are appeared to forms of hole. If protons with various energies enter the two targets with another thickness, number of protons passed through the target per unit area is different each other. Using this feature of protons, we can a proton radiographic image with CR-39. We studied proton radiography with CR-39 by using energetic protons from high power femto-second laser and evaluated potentiality of femto-second laser as new energetic proton generator for radiography

  3. Proof of principle study of the use of a CMOS active pixel sensor for proton radiography.

    Science.gov (United States)

    Seco, Joao; Depauw, Nicolas

    2011-02-01

    Proof of principle study of the use of a CMOS active pixel sensor (APS) in producing proton radiographic images using the proton beam at the Massachusetts General Hospital (MGH). A CMOS APS, previously tested for use in s-ray radiation therapy applications, was used for proton beam radiographic imaging at the MGH. Two different setups were used as a proof of principle that CMOS can be used as proton imaging device: (i) a pen with two metal screws to assess spatial resolution of the CMOS and (ii) a phantom with lung tissue, bone tissue, and water to assess tissue contrast of the CMOS. The sensor was then traversed by a double scattered monoenergetic proton beam at 117 MeV, and the energy deposition inside the detector was recorded to assess its energy response. Conventional x-ray images with similar setup at voltages of 70 kVp and proton images using commercial Gafchromic EBT 2 and Kodak X-Omat V films were also taken for comparison purposes. Images were successfully acquired and compared to x-ray kVp and proton EBT2/X-Omat film images. The spatial resolution of the CMOS detector image is subjectively comparable to the EBT2 and Kodak X-Omat V film images obtained at the same object-detector distance. X-rays have apparent higher spatial resolution than the CMOS. However, further studies with different commercial films using proton beam irradiation demonstrate that the distance of the detector to the object is important to the amount of proton scatter contributing to the proton image. Proton images obtained with films at different distances from the source indicate that proton scatter significantly affects the CMOS image quality. Proton radiographic images were successfully acquired at MGH using a CMOS active pixel sensor detector. The CMOS demonstrated spatial resolution subjectively comparable to films at the same object-detector distance. Further work will be done in order to establish the spatial and energy resolution of the CMOS detector for protons. The

  4. Proton-counting radiography for proton therapy: a proof of principle using CMOS APS technology

    International Nuclear Information System (INIS)

    Poludniowski, G; Esposito, M; Evans, P M; Allinson, N M; Anaxagoras, T; Green, S; Parker, D J; Price, T; Manolopoulos, S; Nieto-Camero, J

    2014-01-01

    Despite the early recognition of the potential of proton imaging to assist proton therapy (Cormack 1963 J. Appl. Phys. 34 2722), the modality is still removed from clinical practice, with various approaches in development. For proton-counting radiography applications such as computed tomography (CT), the water-equivalent-path-length that each proton has travelled through an imaged object must be inferred. Typically, scintillator-based technology has been used in various energy/range telescope designs. Here we propose a very different alternative of using radiation-hard CMOS active pixel sensor technology. The ability of such a sensor to resolve the passage of individual protons in a therapy beam has not been previously shown. Here, such capability is demonstrated using a 36 MeV cyclotron beam (University of Birmingham Cyclotron, Birmingham, UK) and a 200 MeV clinical radiotherapy beam (iThemba LABS, Cape Town, SA). The feasibility of tracking individual protons through multiple CMOS layers is also demonstrated using a two-layer stack of sensors. The chief advantages of this solution are the spatial discrimination of events intrinsic to pixelated sensors, combined with the potential provision of information on both the range and residual energy of a proton. The challenges in developing a practical system are discussed. (paper)

  5. Proton-counting radiography for proton therapy: a proof of principle using CMOS APS technology.

    Science.gov (United States)

    Poludniowski, G; Allinson, N M; Anaxagoras, T; Esposito, M; Green, S; Manolopoulos, S; Nieto-Camero, J; Parker, D J; Price, T; Evans, P M

    2014-06-07

    Despite the early recognition of the potential of proton imaging to assist proton therapy (Cormack 1963 J. Appl. Phys. 34 2722), the modality is still removed from clinical practice, with various approaches in development. For proton-counting radiography applications such as computed tomography (CT), the water-equivalent-path-length that each proton has travelled through an imaged object must be inferred. Typically, scintillator-based technology has been used in various energy/range telescope designs. Here we propose a very different alternative of using radiation-hard CMOS active pixel sensor technology. The ability of such a sensor to resolve the passage of individual protons in a therapy beam has not been previously shown. Here, such capability is demonstrated using a 36 MeV cyclotron beam (University of Birmingham Cyclotron, Birmingham, UK) and a 200 MeV clinical radiotherapy beam (iThemba LABS, Cape Town, SA). The feasibility of tracking individual protons through multiple CMOS layers is also demonstrated using a two-layer stack of sensors. The chief advantages of this solution are the spatial discrimination of events intrinsic to pixelated sensors, combined with the potential provision of information on both the range and residual energy of a proton. The challenges in developing a practical system are discussed.

  6. Proton Radiography to Improve Proton Radiotherapy : Simulation Study at Different Proton Beam Energies

    NARCIS (Netherlands)

    Biegun, Aleksandra; Takatsu, Jun; van Goethem, Marc-Jan; van der Graaf, Emiel; van Beuzekom, Martin; Visser, Jan; Brandenburg, Sijtze

    To improve the quality of cancer treatment with protons, a translation of X-ray Computed Tomography (CT) images into a map of the proton stopping powers needs to be more accurate. Proton stopping powers determined from CT images have systematic uncertainties in the calculated proton range in a

  7. Inspection reliability comparison of digital radiography, film radiography and radioscopy for inspection of Inconel welds

    International Nuclear Information System (INIS)

    Meade, W.; Kidwell, C.; Warren, G.

    2004-01-01

    Digital Radiography offers the promise of economic and environmental advantages over traditional film based inspection. Boeing Commercial Aircraft Group has an on-going effort to evaluate this emerging radiographic method for production of aerospace hardware. Included in this effort was a program to evaluate the potential for utilizing amorphous silicon based digital radiography for the inspection of inconel weldments in engine ducting. For this particular program, probability of detection (POD) studies were conducted to compare the reliability of digital radiography with the existing production processes that utilize film radiography and image-intensifier based radioscopy. Cycle time studies were also conducted to determine the potential economic benefit for switching to the new process. The methodology and findings of this comparison are presented. (author)

  8. Inspection reliability comparison of digital radiography, film radiography and radioscopy for inspection of Inconel welds

    Energy Technology Data Exchange (ETDEWEB)

    Meade, W.; Kidwell, C.; Warren, G. [Boeing Commercial Aircraft Group, Renton, Washington (United States)

    2004-07-01

    Digital Radiography offers the promise of economic and environmental advantages over traditional film based inspection. Boeing Commercial Aircraft Group has an on-going effort to evaluate this emerging radiographic method for production of aerospace hardware. Included in this effort was a program to evaluate the potential for utilizing amorphous silicon based digital radiography for the inspection of inconel weldments in engine ducting. For this particular program, probability of detection (POD) studies were conducted to compare the reliability of digital radiography with the existing production processes that utilize film radiography and image-intensifier based radioscopy. Cycle time studies were also conducted to determine the potential economic benefit for switching to the new process. The methodology and findings of this comparison are presented. (author)

  9. Pencil beam proton radiography using a multilayer ionization chamber

    Science.gov (United States)

    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.

  10. Pencil beam proton radiography using a multilayer ionization chamber.

    Science.gov (United States)

    Farace, Paolo; Righetto, Roberto; Meijers, Arturs

    2016-06-07

    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.

  11. Radiography

    Science.gov (United States)

    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.

  12. Comparison of digital radiography and conventional film screen radiography

    Energy Technology Data Exchange (ETDEWEB)

    Kalender, W A; Huebener, K H

    1984-01-01

    Parameters of image quality, comprising spacial resolution and contrast, have been determined in the form of a contrast/detail diagram for a digital system (Topogram) and a film-screen system. The digital system was particularly examined concerning its contrast sensitivity in relation to quantum noise. The clinical implications of the comparison of the systems, where evaluated on chest X-rays of 250 patients. Despite lower image sharpness, the digital method is already able to produce equivalent or better diagnostic results in certain circumstances. The advantages and disadvantages of both systems are discussed in detail.

  13. A comparison of digital radiography and conventional film screen radiography

    International Nuclear Information System (INIS)

    Kalender, W.A.; Huebener, K.H.; Tuebingen Univ.

    1984-01-01

    Parameters of image quality, comprising spacial resolution and contrast, have been determined in the form of a contrast/detail diagram for a digital system (Topogram) and a film-screen system. The digital system was particularly examined concerning its contrast sensitivity in relation to quantum noise. The clinical implications of the comparison of the systems, where evaluated on chest X-rays of 250 patients. Despite lower image sharpness, the digital method is already able to produce equivalent or better diagnostic results in certain circumstances. The advantages and disadvantages of both systems are discussed in detail. (orig.) [de

  14. Proton radiography of petawatt-driven channel formation in a plasma gradient

    Science.gov (United States)

    Hill, Matthew; Sircombe, Nathan; Ramsay, Martin; Brown, Colin; Hobbs, Lauren; Allan, Peter; James, Steven; Norreys, Peter; Ratan, Naren; Ceurvorst, Luke

    2015-11-01

    Channel formation by ultra-intense laser pulses in underdense plasmas is a challenging simulation problem with direct relevance to many areas of current research. Recent experiments at the Orion laser facility have used high-energy proton radiography (>40 MeV) driven by a 1 ω petawatt beam to directly probe the interaction of another petawatt beam with a well-characterized plasma density gradient. The interaction plasma was generated using a 3 ω long-pulse beam and diagnosed using a 2 ω optical probe, simultaneously imaged onto four gated optical imagers and two streak cameras. The unique capabilities of the Orion facility allowed a comparison of the channels generated by intense 1 ω (1 μm, 100-500 J, 0.6 ps, 1021 W/cm2, f/3 parabola) and 2 ω (0.5 μm, 100 J, 0.6 ps, 1020 W/cm2, f/6 parabola) pulses. Proton radiographs of these channels are presented along with PIC simulations performed using the EPOCH code, supported by K- α measurements of hot electron beam divergence and magnetic spectrometer data. Together these provide a solid foundation for improvements to hydrodynamic and PIC simulations, further developing the predictive capabilities required to optimize future experiments.

  15. Comparison of ultrasonography and radiography in diagnosis of rib fractures.

    Science.gov (United States)

    Pishbin, Elham; Ahmadi, Koorosh; Foogardi, Molood; Salehi, Maryam; Seilanian Toosi, Farrokh; Rahimi-Movaghar, Vafa

    2017-08-01

    Rib fractures are the most common skeletal thoracic injuries resulting from blunt chest trauma. Half of the rib fractures are not detected upon a precise physical evaluation and radiographs. Recently ultrasonography (USG) has been investigated to detect rib fractures. But based on literature the usefulness of USG varies widely. This study was conducted to investigate the role of USG in the detection of possible rib fractures in comparison with radiography. In this cross-sectional study, consecutive patients with minor blunt chest trauma and suspected rib fractures presenting in Imam Reza Hospital located in Mashhad-Iran, between April 2013 and October 2013 were assessed by USG and radiography. The radiography was performed in a posteroanterior (PA) chest projection and oblique rib view centered over the area of trauma. The time duration spent in taking USG and radiography were recorded. The prevalence and location of fractures revealed by USG and radiography were compared. Sixty-one suspected patients were assessed. The male to female ratio was 2.4:1 (43 men and 18 women) with a mean ± SD age of (44.3 ± 19.7) years. There were totally 59 rib fractures in 38 (62.3%) patients based on radiography and USG, while 23 (37.7%) patients had no diagnostic evidence of rib lesions. USG revealed 58 rib fractures in 33 (54.1%) of 61 suspected patients and radiographs revealed 32 rib fractures in 20 (32.8%) of 61 patients. A total of 58 (98.3%) rib fractures were detected by USG, whereas oblique rib view and PA chest radiography showed 27 (45.8%) and 24 (40.7%) rib fractures, respectively. The average duration of USG was (12 ± 3) min (range 7-17 min), whereas the duration of radiography was (27 ± 6) min (range 15-37 min). The kappa coefficient showed a low level of agreement between both USG and PA chest radiography (kappa coefficient = 0.28), and between USG and oblique rib view (kappa coefficient = 0.32). USG discloses more fractures than radiography in

  16. Proton Radiography of Laser-Plasma Interactions with Picosecond Time Resolution

    International Nuclear Information System (INIS)

    Mackinnon, A J; Patel, P K; Town, R J; Hatchett, S P; Hicks, D; Phillips, T H; Wilks, S C; Price, D; Key, M H; Lasinski, B; Langdon, B; Borghesi, M; Romagnani, L; Kar, S

    2005-01-01

    Radiography of laser-produced plasmas with MeV protons has the potential to provide new information on plasma conditions in extreme states of matter. Protons with energies up to many hundreds MeV, produced by large scale accelerators have been recently been used to obtain mass density radiographs of the behavior of large samples which have been shocked on microsecond timescales with approximately mm spatial resolution. The recent discovery of laminar proton beams accelerated to multi-MeV energies by picosecond duration laser beams has provided the opportunity to probe dense plasmas with hitherto unparalleled temporal and spatial resolution

  17. The optimal balance between quality and efficiency in proton radiography imaging technique at various proton beam energies : A Monte Carlo study

    NARCIS (Netherlands)

    Biegun, A K; van Goethem, M-J; van der Graaf, E R; van Beuzekom, M; Koffeman, E N; Nakaji, T; Takatsu, J; Visser, J; Brandenburg, S

    Proton radiography is a novel imaging modality that allows direct measurement of the proton energy loss in various tissues. Currently, due to the conversion of so-called Hounsfield units from X-ray Computed Tomography (CT) into relative proton stopping powers (RPSP), the uncertainties of RPSP are

  18. WE-EF-303-10: Single- Detector Proton Radiography as a Portal Imaging Equivalent for Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Doolan, P [University College London Hospital, London (United Kingdom); Bentefour, E [Ion Beam Applications, Louvain-la-Neuve (Belgium); Testa, M; Cascio, E; Lu, H [Massachussetts General Hospital, Boston, MA (United States); Royle, G [University College London, London (United Kingdom); Gottschalk, B [Harvard University, Cambridge, MA (United States)

    2015-06-15

    Purpose: In proton therapy, patient alignment is of critical importance due to the sensitivity of the proton range to tissue heterogeneities. Traditionally proton radiography is used for verification of the water-equivalent path length (WEPL), which dictates the depth protons reach. In this work we propose its use for alignment. Additionally, many new proton centers have cone-beam computed tomography in place of beamline X-ray imaging and so proton radiography offers a unique patient alignment verification similar to portal imaging in photon therapy. Method: Proton radiographs of a CIRS head phantom were acquired using the Beam Imaging System (BIS) (IBA, Louvain-la-Neuve) in a horizontal beamline. A scattered beam was produced using a small, dedicated, range modulator (RM) wheel fabricated out of aluminum. The RM wheel was rotated slowly (20 sec/rev) using a stepper motor to compensate for the frame rate of the BIS (120 ms). Dose rate functions (DRFs) over two RM wheel rotations were acquired. Calibration was made with known thicknesses of homogeneous solid water. For each pixel the time width, skewness and kurtosis of the DRFs were computed. The time width was used to compute the object WEPL. In the heterogeneous phantom, the excess skewness and excess kurtosis (i.e. difference from homogeneous cases) were computed and assessed for suitability for patient set up. Results: The technique allowed for the simultaneous production of images that can be used for WEPL verification, showing few internal details, and excess skewness and kurtosis images that can be used for soft tissue alignment. These latter images highlight areas where range mixing has occurred, correlating with phantom heterogeneities. Conclusion: The excess skewness and kurtosis images contain details that are not visible in the WET images. These images, unique to the time-resolved proton radiographic method, could be used for patient set up according to soft tissues.

  19. WE-EF-303-04: An Advanced Image Processing Method to Improve the Spatial Resolution of Proton Radiographies

    International Nuclear Information System (INIS)

    Rinaldi, I; Parodi, K; Krah, N

    2015-01-01

    Purpose: We present an optimization method to improve the spatial resolution and the water equivalent thickness accuracy of proton radiographies. Methods: The method is designed for imaging systems measuring only the residual range of protons without relying on tracker detectors to determine the beam trajectory before and after the target. Specifically, the method was used for an imaging set-up consisting of a stack of 61 parallel-plate ionization chambers (PPIC) working as a range telescope. The method uses a decomposition approach of the residual range signal measured by the PPIC and constructs subimages with small size pixels geometrically rearranged and appropriately averaged to be merged into a final single radiography. The method was tested using Monte Carlo simulated and experimental proton radiographies of a PMMA step phantom and an anthropomorphic head phantom. Results: For the step phantom, the effective spatial resolution was found to be 4 and 3 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 X-ray radiography convolved with a Gaussian kernel equal to the proton beam spot-size. For DTA=2.5 mm and RD=2.5%, the passing ratio was 100%/85% for the optimized/non-optimized case, respectively. An extension of the method allows reducing the dose given to the patient during radiography acquisition. We show that despite a dose reduction of 25 times (leading to a dose of 0.016 mGy for the current imaging set-up), the image quality of the optimized radiographies remains fairly unaffected for both the simulated and experimental results. Conclusion: The optimization method leads to a significant increase of the spatial resolution allowing recovering image details that are unresolved in non-optimized radiographies. These results represent a major step towards clinical

  20. Energy deposition in a thin copper target downstream and off-axis of a proton-radiography target

    International Nuclear Information System (INIS)

    Greene, G.A.; Finfrock, C.C.; Snead, C.L.; Hanson, A.L.; Murray, M.M.

    2002-01-01

    A series of proton energy-deposition experiments was conducted to measure the energy deposited in a copper target located downstream and off-axis of a high-energy proton-radiography target. The proton/target interactions involved low-intensity bunches of protons at 24 GeV/c onto a spherical target consisting of concentric shells of tungsten and copper. The energy-deposition target was placed at five locations downstream of the proton-radiography target, off-axis of the primary beam transport, and was either unshielded or shielded by 5 or 10 cm of lead. Maximum temperature rises measured in the energy-deposition target due to single bunches of 5x10 10 protons on the proton-radiography target were approximately 20 mK per bunch. The data indicated that the scattered radiation was concentrated close to the primary transport axis of the beam line. The energy deposited in the energy-deposition target was reduced by moving the target radially away from the primary transport axis. Placing lead shielding in front of the target further reduced the energy deposition. The measured temperature rises of the energy-deposition target were empirically correlated with the distance from the source, the number of protons incident on the proton-radiography target, the thickness of the lead shielding, and the angle of the energy-deposition target off-axis of the beam line from the proton-radiography target. The correlation of the experimental data that was developed provides a starting point for the evaluation of the shielding requirements for devices downstream of proton-radiography targets such as superconducting magnets

  1. Comparison of ultrasonography and radiography in diagnosis of rib fractures

    OpenAIRE

    Pishbin, Elham; Ahmadi, Koorosh; Foogardi, Molood; Salehi, Maryam; Seilanian Toosi, Farrokh; Rahimi-Movaghar, Vafa

    2017-01-01

    Purpose: Rib fractures are the most common skeletal thoracic injuries resulting from blunt chest trauma. Half of the rib fractures are not detected upon a precise physical evaluation and radiographs. Recently ultrasonography (USG) has been investigated to detect rib fractures. But based on literature the usefulness of USG varies widely. This study was conducted to investigate the role of USG in the detection of possible rib fractures in comparison with radiography. Methods: In this cross-s...

  2. Quality comparison of direct digital panoramic radiography and computed radiography panoramic

    Directory of Open Access Journals (Sweden)

    Dariush Goodarzipour

    2013-09-01

    Full Text Available BACKGROUND AND AIM: Digital panoramic X-ray images can be captured using photostimulable phosphors or solid-state detectors (i.e. charge-coupled devices and Flat-Panels. The first category is defined as computed radiography (CR or semi-direct radiography. The second technology that uses solid-state detectors is known as direct digital radiography (DDR. Both of these technologies have their own advantages and disadvantages. One of the most important fields in comparison of these systems is their resultant image quality. The purpose of this study was to compare the subjective image quality of DDR and CR digital panoramic system, and to assess the overall density and contrast of their images. METHODS: 200 patients were randomly allocated to two digital systems: Promax [central control digital (CCD] and XC [photostimulable phosphor plates (PSP]. Image quality was evaluated in six regions on a 3-point scale by three oral and maxillofacial radiologists independently. In addition, observers assessed overall density and contrast of each image on a 3-point scale. RESULTS: Using chi-square test, no statistically significant differences were found (P >0.05 in subjective image quality of anatomic structures between the two radiographic systems. But DDR system outperformed CR system in overall density and contrast of the image. P values for both overall density and contrast of the images was less than 0.001. CONCLUSIONS: The subjective image quality of CR and DDR panoramic systems in specified anatomic regions were found statistically comparable in this study. In overall density and contrast of the radiographs, DDR system proved better than CR system.

  3. Vertebral Fracture Assessment in Supine Position : Comparison by Using Conventional Semiquantitative Radiography and Visual Radiography

    NARCIS (Netherlands)

    Hospers, Ilone C.; van der Laan, Johan G.; Zeebregts, Clark J.; Nieboer, Patrick; Wolffenbuttel, Bruce H. R.; Dierckx, Rudi A.; Kreeftenberg, Herman G.; Jager, Pieter L.; Slart, Riemer H. J. A.

    Purpose: To retrospectively evaluate the accuracy of vertebral fracture assessment (VFA) performed with the patient in the supine position and conventional semiquantitative radiography of the spine by using conventional visual radiography of the spine as the reference standard. Materials and

  4. FINAL SCIENTIFIC REPORT - PROTON RADIOGRAPHY: CROSS SECTION MEASUREMENTS AND DETECTOR DEVELOPMENT

    International Nuclear Information System (INIS)

    Longo, Michael J.; Gustafson, H. Richard.; Rajaram, Durga; Nigmanov, Turgun

    2007-01-01

    Proton radiography offers significant advantages over conventional X-ray radiography, including the capability of looking into thick, dense materials, better contrast for a wide range of materials, sensitivity to different materials of similar density, and better resolution because of the ability to focus beams. In order to achieve this capability it is crucial to understand the background due to neutrons and photons and to develop techniques to reduce it to tolerable levels. 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 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 calorimeters. These are the only detectors in the experiment that provide information on neutrons and photons. We are taking a leading role in obtaining and analyzing the for-ward production data and in developing an optimal detector for proton radiography. With the support of our Stewardship Science Academic Alliances grant, we were able to design, build, and commission the calorimeters on budget and ahead of schedule. E-907 officially started physics running at Fermilab in January 2005, and data taking continued through February 2006. Data were taken on a range of targets, from liquid hydrogen to uranium, at beam energies from 5 GeV/c to 120 GeV/c. The analysis of the data is challenging because data from many different detector systems must be understood and merged and over 31 million events were accumulated. Our recent efforts have been devoted to the calibration of the neutron and photon detectors, to track and shower reconstruction, identification of forward-going neutrons, and simulation of the calorimeters in a Monte Carlo. Reconstruction of the data with improved tracking is underway

  5. Improvement of single detector proton radiography by incorporating intensity of time-resolved dose rate functions

    Science.gov (United States)

    Zhang, Rongxiao; Jee, Kyung-Wook; Cascio, Ethan; Sharp, Gregory C.; Flanz, Jacob B.; Lu, Hsiao-Ming

    2018-01-01

    Proton radiography, which images patients with the same type of particles as those with which they are to be treated, is a promising approach to image guidance and water equivalent path length (WEPL) verification in proton radiation therapy. We have shown recently that proton radiographs could be obtained by measuring time-resolved dose rate functions (DRFs) using an x-ray amorphous silicon flat panel. The WEPL values were derived solely from the root-mean-square (RMS) of DRFs, while the intensity information in the DRFs was filtered out. In this work, we explored the use of such intensity information for potential improvement in WEPL accuracy and imaging quality. Three WEPL derivation methods based on, respectively, the RMS only, the intensity only, and the intensity-weighted RMS were tested and compared in terms of the quality of obtained radiograph images and the accuracy of WEPL values. A Gammex CT calibration phantom containing inserts made of various tissue substitute materials with independently measured relative stopping powers (RSP) was used to assess the imaging performances. Improved image quality with enhanced interfaces was achieved while preserving the accuracy by using intensity information in the calibration. Other objects, including an anthropomorphic head phantom, a proton therapy range compensator, a frozen lamb’s head and an ‘image quality phantom’ were also imaged. Both the RMS only and the intensity-weighted RMS methods derived RSPs within  ±  1% for most of the Gammex phantom inserts, with a mean absolute percentage error of 0.66% for all inserts. In the case of the insert with a titanium rod, the method based on RMS completely failed, whereas that based on the intensity-weighted RMS was qualitatively valid. The use of intensity greatly enhanced the interfaces between different materials in the obtained WEPL images, suggesting the potential for image guidance in areas such as patient positioning and tumor tracking by proton

  6. A survey of high explosive-induced damage and spall in selected metals using proton radiography

    International Nuclear Information System (INIS)

    Holtkamp, D.B.; Clark, D.A.; Ferm, E.N.; Gallegos, R.A.; Hammon, D.; Hemsing, W.F.; Hogan, G.E.; Holmes, V.H.; King, N.S.P.; Lopez, R.P.; Merrill, F.E.; Morris, C.L.; Morley, K.B.; Murray, M.M.; Pazuchanics, P.D.; Prestridge, K.P.; Quintana, J.P.; Saunders, A.; Shinas, M.A.; Stacy, H.L.

    2004-01-01

    Multiple spall and damage layers can be created in metal when the free surface reflects a Taylor wave generated by high explosives. These phenomena have been explored in different thicknesses of several metals (tantalum, copper, 6061 T6-aluminum, and tin) using high-energy proton radiography. Multiple images (up to 21) can be produced of the dynamic evolution of damaged material on the microsecond time scale with a <50 ns 'shutter' time. Movies and multiframe still images of areal and (Abel inverted) volume densities are presented. An example of material that is likely melted on release (tin) is also presented

  7. The scrounge-atron: a phased approach to the advanced hydrotest facility utilizing proton radiography

    International Nuclear Information System (INIS)

    Alford, O.J.; Barnes, P.D. Jr.; Chargin, A.K.; Dekin, W.D.; Hartouni, E.P.; Hockman, J.; Hockman, J.N.; Ladran, A.S.; Libkind, M.A.; Moore, T.L.; Ohnuma, S.; Pastrnak, J.W.; Pico, R.E.; Ruggiero, A.G.; Souza, R.J.; Stoner, J.M.; Wilson, J.H.

    1999-01-01

    The Department of Energy has initiated its Stockpile Stewardship and Management Program (SSMP) to provide a single, integrated technical program for maintaining the continued safety and reliability of the nation's nuclear weapons stockpile in the absence of nuclear testing. Consistent with the SSMP, the Advanced Hydrotest Facility (AHF) has been conceived to provide improved radiographic imaging with multiple axes and multiple time frames. The AHF would be used to better understand the evolution of nuclear weapon primary implosion shape under normal and accident scenarios. There are three fundamental technologies currently under consideration for use on the AHF. These include linear induction acceleration, inductive-adder pulsed-power technology (both technologies using high current electron beams to produce an intense X-ray beam) and high-energy proton accelerators to produce a proton beam. The Scrounge-atron (a proton synchrotron) was conceived to be a relatively low cost demonstration of the viability of the third technology using bursts of energetic protons, magnetic lenses, and particle detectors to produce the radiographic image. In order for the Scrounge-atron to provide information useful for the AHF technology decision, the accelerator would have to be built as quickly and as economically as possible. These conditions can be met by scrounging parts from decommissioned accelerators across the country, especially the Main Ring at Fermilab. The Scrounge-atron is designed to meet the baseline parameters for single axis proton radiography: a 20 GeV proton beam of ten pulses, 10 11 protons each, spaced 250 ns apart

  8. Neutron radiography characterization of an operating proton exchange membrane fuel cell with localized current distribution measurements

    International Nuclear Information System (INIS)

    Gagliardo, J.J.; Owejan, J.P.; Trabold, T.A.; Tighe, T.W.

    2009-01-01

    Neutron radiography has proven to be a powerful tool to study and understand the effects of liquid water in an operating fuel cell. In the present work, this experimental method is coupled with locally resolved current and ohmic resistance measurements, giving additional insight into water management and fuel cell performance under a variety of conditions. The effects of varying the inlet humidification level and the current density of the 50 cm 2 cell are studied by simultaneously monitoring electrochemical performance with a 10x10 matrix of current sensors, and liquid water volumes are measured using the National Institute of Standards and Technology (NIST) neutron imaging facility. A counter flow, straight channel proton exchange membrane (PEM) fuel cell is used to demonstrate localized performance loss corresponds to water-filled channels that impede gas transport to the catalyst layer, thereby creating an area that has low current density. Furthermore, certain operating conditions causing excess water accumulation in the channels can result in localized proton resistance increase, a result that can only be accurately observed with combined radiography and distributed electrochemical measurements.

  9. Development of an interpretive simulation tool for the proton radiography technique

    Energy Technology Data Exchange (ETDEWEB)

    Levy, M. C., E-mail: levymc@stanford.edu [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Ryutov, D. D.; Wilks, S. C.; Ross, J. S.; Huntington, C. M.; Fiuza, F.; Martinez, D. A.; Park, H.-S. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Kugland, N. L. [Lam Research Corporation, 4400 Cushing Parkway, Fremont, California 94538 (United States); Baring, M. G. [Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

    2015-03-15

    Proton radiography is a useful diagnostic of high energy density (HED) plasmas under active theoretical and experimental development. In this paper, we describe a new simulation tool that interacts realistic laser-driven point-like proton sources with three dimensional electromagnetic fields of arbitrary strength and structure and synthesizes the associated high resolution proton radiograph. The present tool’s numerical approach captures all relevant physics effects, including effects related to the formation of caustics. Electromagnetic fields can be imported from particle-in-cell or hydrodynamic codes in a streamlined fashion, and a library of electromagnetic field “primitives” is also provided. This latter capability allows users to add a primitive, modify the field strength, rotate a primitive, and so on, while quickly generating a high resolution radiograph at each step. In this way, our tool enables the user to deconstruct features in a radiograph and interpret them in connection to specific underlying electromagnetic field elements. We show an example application of the tool in connection to experimental observations of the Weibel instability in counterstreaming plasmas, using ∼10{sup 8} particles generated from a realistic laser-driven point-like proton source, imaging fields which cover volumes of ∼10 mm{sup 3}. Insights derived from this application show that the tool can support understanding of HED plasmas.

  10. Development of an interpretive simulation tool for the proton radiography technique

    Science.gov (United States)

    Levy, M. C.; Ryutov, D. D.; Wilks, S. C.; Ross, J. S.; Huntington, C. M.; Fiuza, F.; Martinez, D. A.; Kugland, N. L.; Baring, M. G.; Park, H.-S.

    2015-03-01

    Proton radiography is a useful diagnostic of high energy density (HED) plasmas under active theoretical and experimental development. In this paper, we describe a new simulation tool that interacts realistic laser-driven point-like proton sources with three dimensional electromagnetic fields of arbitrary strength and structure and synthesizes the associated high resolution proton radiograph. The present tool's numerical approach captures all relevant physics effects, including effects related to the formation of caustics. Electromagnetic fields can be imported from particle-in-cell or hydrodynamic codes in a streamlined fashion, and a library of electromagnetic field "primitives" is also provided. This latter capability allows users to add a primitive, modify the field strength, rotate a primitive, and so on, while quickly generating a high resolution radiograph at each step. In this way, our tool enables the user to deconstruct features in a radiograph and interpret them in connection to specific underlying electromagnetic field elements. We show an example application of the tool in connection to experimental observations of the Weibel instability in counterstreaming plasmas, using ˜108 particles generated from a realistic laser-driven point-like proton source, imaging fields which cover volumes of ˜10 mm3. Insights derived from this application show that the tool can support understanding of HED plasmas.

  11. Dose ratio proton radiography using the proximal side of the Bragg peak

    Energy Technology Data Exchange (ETDEWEB)

    Doolan, P. J., E-mail: paul.doolan.09@ucl.ac.uk; Royle, G.; Gibson, A. [Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT (United Kingdom); Lu, H.-M. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States); Prieels, D.; Bentefour, E. H. [Ion Beam Applications (IBA), 3 Chemin du Cyclotron, Louvain la Neuve B-1348 (Belgium)

    2015-04-15

    Purpose: In recent years, there has been a movement toward single-detector proton radiography, due to its potential ease of implementation within the clinical environment. One such single-detector technique is the dose ratio method in which the dose maps from two pristine Bragg peaks are recorded beyond the patient. To date, this has only been investigated on the distal side of the lower energy Bragg peak, due to the sharp falloff. The authors investigate the limits and applicability of the dose ratio method on the proximal side of the lower energy Bragg peak, which has the potential to allow a much wider range of water-equivalent thicknesses (WET) to be imaged. Comparisons are made with the use of the distal side of the Bragg peak. Methods: Using the analytical approximation for the Bragg peak, the authors generated theoretical dose ratio curves for a range of energy pairs, and then determined how an uncertainty in the dose ratio would translate to a spread in the WET estimate. By defining this spread as the accuracy one could achieve in the WET estimate, the authors were able to generate lookup graphs of the range on the proximal side of the Bragg peak that one could reliably use. These were dependent on the energy pair, noise level in the dose ratio image and the required accuracy in the WET. Using these lookup graphs, the authors investigated the applicability of the technique for a range of patient treatment sites. The authors validated the theoretical approach with experimental measurements using a complementary metal oxide semiconductor active pixel sensor (CMOS APS), by imaging a small sapphire sphere in a high energy proton beam. Results: Provided the noise level in the dose ratio image was 1% or less, a larger spread of WETs could be imaged using the proximal side of the Bragg peak (max 5.31 cm) compared to the distal side (max 2.42 cm). In simulation, it was found that, for a pediatric brain, it is possible to use the technique to image a region with a

  12. The mechanical design of a proton microscope for radiography at 800 MeV

    International Nuclear Information System (INIS)

    Valdiviez, R.; Sigler, F.E.; Barlow, D.B.; Blind, B.; Jason, A.J.; Mottershead, C.T.; Gomez, J.J.; Espinoza, C.J.

    2003-01-01

    A proton microscope has been developed for radiography applications using the 800-MeV linear accelerator at the Los Alamos Neutron Science Center (LANSCE). The microscope provides a magnified image of a static device, or of a dynamic event such as a high-speed projectile impacting a target. The microscope assembly consists primarily of four Permanent Magnet Quadrupoles (PMQ's) that are supported on movable platforms. The platform supports, along with the rest of the support structure, are designed to withstand the residual dynamic loads that are expected from the dynamic tests. This paper covers the mechanical design of the microscope assembly, including the remote positioning system that allows for fine-tuning the focus of an object being imaged.

  13. Direct Observation of the Phenomenology of a Solid Thermal Explosion Using Time-Resolved Proton Radiography

    International Nuclear Information System (INIS)

    Smilowitz, L.; Henson, B. F.; Romero, J. J.; Asay, B. W.; Schwartz, C. L.; Saunders, A.; Merrill, F. E.; Morris, C. L.; Kwiatkowski, K.; Hogan, G.; Nedrow, P.; Murray, M. M.; Thompson, T. N.; McNeil, W.; Rightley, P.; Marr-Lyon, M.

    2008-01-01

    We present a new phenomenology for burn propagation inside a thermal explosion based on dynamic radiography. Radiographic images were obtained of an aluminum cased solid cylindrical sample of a plastic bonded formulation of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine. The phenomenology observed is ignition followed by cracking in the solid accompanied by the propagation of a radially symmetric front of increasing proton transmission. This is followed by a further increase in transmission through the sample, ending after approximately 100 μs. We show that these processes are consistent with the propagation of a convective burn front followed by consumption of the remaining solid by conductive particle burning

  14. Comparison of the efficacy of conventional radiography, digital radiography, and ultrasound in diagnosing periapical lesions.

    Science.gov (United States)

    Raghav, Namita; Reddy, Sujatha S; Giridhar, A G; Murthy, Srinivas; Yashodha Devi, B K; Santana, N; Rakesh, N; Kaushik, Atul

    2010-09-01

    The aim of this study was to evaluate the efficacy of conventional radiography, digital radiography and ultrasound imaging in diagnosing periapical lesions. Twenty-one patients aged between 15 and 45 years with well defined periapical radiolucency associated with anterior maxillary or mandibular teeth requiring endodontic surgery or extraction were selected and consented to the study. Preoperative intraoral periapical radiographs and digital images using charge-coupled device obtained by paralleling technique were assessed by 3 specialist observers who gave their diagnosis of the periapical lesions. Then ultrasound examination was performed and the images were assessed for size, contents, and vascular supply by 3 ultrasonographers. It was followed by curettage of periapical tissues to enable histopathologic investigation, which is the gold standard in diagnosis. The data were statistically analyzed using SPSS, analysis of variance, and kappa statistics. The percentage accuracy of diagnosing periapical lesions using conventional radiography was 47.6%, digital radiography 55.6%, and ultrasound 95.2%. Ultrasound had the highest sensitivity and specificity: 0.95 and 1.00, respectively. Conventional and digital radiography enable diagnosis of periapical diseases, but not their nature, whereas ultrasound provides accurate information on the pathologic nature of the lesions, which is of importance in predicting the treatment outcome. Therefore ultrasound can be used as an adjunct to conventional or digital radiography in diagnosing periapical lesions. Copyright (c) 2010 Mosby, Inc. All rights reserved.

  15. Micromachining of commodity plastics by proton beam writing and fabrication of spatial resolution test-chart for neutron radiography

    International Nuclear Information System (INIS)

    Sakai, T.; Yasuda, R.; Iikura, H.; Nojima, T.; Matsubayashi, M.; Kada, W.; Kohka, M.; Satoh, T.; Ohkubo, T.; Ishii, Y.; Takano, K.

    2013-01-01

    Proton beam writing is a direct-write technique and a promising method for the micromachining of commodity plastics such as acrylic resins. Herein, we describe the fabrication of microscopic devices made from a relatively thick (∼75 μm) acrylic sheet using proton beam writing. In addition, a software package that converts image pixels into coordinates data was developed, and the successful fabrication of a very fine jigsaw puzzle was achieved. The size of the jigsaw puzzle pieces was 50 × 50 μm. For practical use, a prototype of a line and space test-chart was also successfully fabricated for the determination of spatial resolution in neutron radiography

  16. Detectability of the mediastinal lines : comparison of conventional film-screen radiography and digital radiography

    International Nuclear Information System (INIS)

    Shin, Hye Young; Park, Kyung Joo; Kang, Doo Kyung; Lee, Kang Lai; Han, Chaing Jin; Suh, Jung Ho

    1998-01-01

    Using dynamic range compression (DRC) processing, this study compared the detectability of mediastinal lines by conventional film screen radiography (FS) and by storage phosphor digital radiography (DR). We selected 200 normal consecutive chest radiographs (100 FS, 100 DR); dynamic range compression was applied to DR processing and moving grids were used in both systems. Seven mediastinal lines (left paraspinal, right paraspinal, azygoesophageal, left para-aortic, posterio junctional, anterior junctional and right paratracheal) were scored from 0 point to 3 point (0: not visible, 1 : suspiciously visible, 2 : visible, but not clear, 3: clearly visible) according to visibility and sharpness, as agreed by a radiologist and a resident. The differences between the two modalities were compared and analyzed by chi-square test. DR processed with DRC visualizes mediastinal lines more frequently and clearly than conventional FS, and is therefore thought to be useful for the evaluation of mediastinal diseases. (author). 14 refs., 2 tabs., 2 figs

  17. SU-E-J-158: Experimental Investigation of Proton Radiography Based On Time-Resolved Dose Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Testa, M; Paganetti, H; Lu, H-M [Massachusetts General Hospital ' Harvard Medical School, Boston, MA (United States); Doolan, P [University College London (United Kingdom); H, Bentefour E [IBA, Warrenville, IL (United States)

    2014-06-01

    Purpose: To use proton radiography for i) in-vivo range verification of the brain fields of medulloblastoma patients in order to reduce the exit dose to the cranial skin and thus the risk of permanent alopecia; ii) for performing patient specific optimization of the calibration from CT-Hounsfield units to proton relative stopping power in order to minimize uncertainties of proton rang Methods: We developed and tested a prototype proton radiography system based on a single-plane scintillation screen coupled with a fast CCD camera (1ms sampling rate, 0.29x0.29 mm{sup 2} pixel size, 30×30 cm{sup 2} field of view). The method is based on the principle that, for passively scattered beams, the radiological depth of any point in the plateau of a spread-out Bragg-Peak (SOBP) can be inferred from the time-pattern of the dose rate measurements. We performed detector characterization measurements using complex-shape homogeneous phantoms and an Alderson phanto Results: Detector characterization tests confirmed the robustness of the technique. The results of the phantom measurements are encouraging in terms of achievable accuracy of the water equivalent thickness. A technique to minimize the degradation of spatial resolution due to multiple Coulomb scattering is discussed. Our novel radiographic technique is rapid (100 ms) and simultaneous over the whole field. The dose required to produce one radiograph, with the current settings, is ∼3 cG Conclusion: The results obtained with this simple and innovative radiography method are promising and motivate further development of technique. The system requires only a single-plane 2D dosimeter and it uses the clinical beam for a fraction of second with low dose to the patient.

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

    Directory of Open Access Journals (Sweden)

    Wilton Mitsunari Takeshita

    2013-01-01

    Full Text Available 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.

  19. Contrast-Enhanced Proton Radiography for Patient Set-up by Using X-Ray CT Prior Knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Spadea, Maria Francesca, E-mail: mfspadea@unicz.it [Department of Experimental and Clinical Medicine, Magna Graecia University, Catanzaro (Italy); Fassi, Aurora [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Zaffino, Paolo [Department of Experimental and Clinical Medicine, Magna Graecia University, Catanzaro (Italy); Riboldi, Marco; Baroni, Guido [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit—CNAO Foundation, Pavia (Italy); Depauw, Nicolas [Department of Radiation Oncology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts (United States); Centre for Medical Radiation Physics, University of Wollongong, Wollongong (Australia); Seco, Joao [Department of Radiation Oncology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts (United States)

    2014-11-01

    Purpose: To obtain a contrasted image of the tumor region during the setup for proton therapy in lung patients, by using proton radiography and x-ray computed tomography (CT) prior knowledge. Methods and Materials: Six lung cancer patients' CT scans were preprocessed by masking out the gross tumor volume (GTV), and digitally reconstructed radiographs along the planned beam's eye view (BEV) were generated, for a total of 27 projections. Proton radiographies (PR) were also computed for the same BEV through Monte Carlo simulations. The digitally reconstructed radiograph was subtracted from the corresponding proton image, resulting in a contrast-enhanced proton radiography (CEPR). Michelson contrast analysis was performed both on PR and CEPR. The tumor region was then automatically segmented on CEPR and compared to the ground truth (GT) provided by physicians in terms of Dice coefficient, accuracy, precision, sensitivity, and specificity. Results: Contrast on CEPR was, on average, 4 times better than on PR. For 10 lateral projections (±45° off of 90° or 270°), although it was not possible to distinguish the tumor region in the PR, CEPR offers excellent GTV visibility. The median ± quartile values of Dice, precision, and accuracy indexes were 0.86 ± 0.03, 0.86 ± 0.06, and 0.88 ± 0.02, respectively, thus confirming the reliability of the method in highlighting tumor boundaries. Sensitivity and specificity analysis demonstrated that there is no systematic over- or underestimation of the tumor region. Identification of the tumor boundaries using CEPR resulted in a more accurate and precise definition of GTV compared to that obtained from pretreatment CT. Conclusions: In most proton centers, the current clinical protocol is to align the patient using kV imaging with bony anatomy as a reference. We demonstrated that CEPR can significantly improve tumor visualization, allowing better patient set-up and permitting image guided proton therapy (IGPT)

  20. Comparison of the quality of the chest film between digital radiography and conventional high kV radiography

    International Nuclear Information System (INIS)

    Zeng Qingsi; Cen Renli; Chen Ling; He Jianxun; Lin Hanfei

    2003-01-01

    Objective: To evaluate the quality and usefulness of direct digital radiography system in roentgenogram of chest in clinical practice. Methods: 1000 cases of chest roentgenograms with digital radiography and high kV conventional radiography were selected for analysis by 3 senior radiologists. Results: 1. With digital radiography system, the quality of chest film was assessed as grade A in 50.6%, grade B in 38.5%, grade C in 10.9%, and no waste film. 2. With conventional high kV radiography, the quality of chest film was assessed as grade A in 41.1%, grade B in 44.1%, grade C in 13.3%, and waste film in 1.5%. The direct digital radiography was statistically superior to the conventional high kV radiography. 3. The fine structure of the lungs could be revealed in 100.0% of chest roentgenogram with direct digital radiograph system, which was significantly higher than that acquired with the conventional high KV radiography (78.6%, P < 0.001). Conclusion: Direct digital radiography could provide the chest film with better quality than that with the conventional high kV radiography. The direct digital radiography system is easy to operate, fast in capturing imaging and could provide post-processing techniques, which will facilitate the accurate diagnosis of chest radiography

  1. Proton dosimetry comparison involving ionometry and calorimetry

    International Nuclear Information System (INIS)

    Delacroix, Sabine; Bridier, Andre; Mazal, Alexandre; Daures, Josiane; Ostrowsky, Aime; Nauraye, Catherine; Kacperek, Andre; Vynkier, Stephane; Brassard, Nicole; Habrand, Jean-Louis

    1997-01-01

    A comparison of the absorbed dose to tissue determined by various ionization chambers, Faraday cups, and an A-150 plastic calorimeter was performed in the 200 MeV proton beam of Orsay, France. Four European proton-therapy centers (Clatterbridge, UK, Louvain la Neuve, Belgium, and Nice and Orsay, France) participated in the comparison. An agreement of better than 1% was observed in the absorbed dose to A-150 measured with the different chambers of the participating groups. The mean ratio of the absorbed dose to A-150 determined with the calorimeter to that determined by the different ionization chambers in the different irradiation conditions was found to be 0.952 ± 0.007 [1 standard deviation (SD)] according to the code of practice used by all the participating centers, based on Janni's tables of stopping powers and a value of 35.2 J/Coulomb for (W air /e) p . A better agreement in the mean ratio calorimeter/chamber, 0.985 ± 0.007 (1 SD) is observed when using the proton stopping power ratio values recently published by the International Commission on Radiation Units and Measurements in Report no. 49. The mean ratio of these doses determined in accordance with the American Association of Physicists in Medicine protocol and using the new recommended stopping power tables becomes 1.002 ± 0.007 (1 SD). Two Faraday cups agree in measured charge to within 0.8%; however, the calculation of dose is underestimated by up to 17%; compared with ion chamber measurements and seems to be very sensitive to measurement conditions, particularly to the distance to the collimator

  2. SU-G-TeP2-13: Patient-Specific Reduction of Range Uncertainties in Proton Therapy by Proton Radiography with a Multi-Layer Ionization Chamber

    International Nuclear Information System (INIS)

    Deffet, S; Macq, B; Farace, P; Righetto, R; Vander Stappen, F

    2016-01-01

    Purpose: The conversion from Hounsfield units (HU) to stopping powers is a major source of range uncertainty in proton therapy (PT). Our contribution shows how proton radiographs (PR) acquired with a multi-layer ionization chamber in a PT center can be used for accurate patient positioning and subsequently for patient-specific optimization of the conversion from HU to stopping powers. Methods: A multi-layer ionization chamber was used to measure the integral depth-dose (IDD) of 220 MeV pencil beam spots passing through several anthropomorphic phantoms. The whole area of interest was imaged by repositioning the couch and by acquiring a 45×45 mm"2 frame for each position. A rigid registration algorithm was implemented to correct the positioning error between the proton radiographs and the planning CT. After registration, the stopping power map obtained from the planning CT with the calibration curve of the treatment planning system was used together with the water equivalent thickness gained from two proton radiographs to generate a phantom-specific stopping power map. Results: Our results show that it is possible to make a registration with submillimeter accuracy from proton radiography obtained by sending beamlets separated by more than 1 mm. This was made possible by the complex shape of the IDD due to the presence of lateral heterogeneities along the path of the beam. Submillimeter positioning was still possible with a 5 mm spot spacing. Phantom specific stopping power maps obtained by minimizing the range error were cross-verified by the acquisition of an additional proton radiography where the phantom was positioned in a random but known manner. Conclusion: Our results indicate that a CT-PR registration algorithm together with range-error based optimization can be used to produce a patient-specific stopping power map. Sylvain Deffet reports financial funding of its PhD thesis by Ion Beam Applications (IBA) during the confines of the study and outside the

  3. SU-G-TeP2-13: Patient-Specific Reduction of Range Uncertainties in Proton Therapy by Proton Radiography with a Multi-Layer Ionization Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Deffet, S; Macq, B [Universite catholique de Louvain, Louvain-la-Neuve (Belgium); Farace, P; Righetto, R [Trento Hospital / APSS, Trento (Italy); Vander Stappen, F [Ion Beam Applications (IBA), Louvain-la-Neuve (Belgium)

    2016-06-15

    Purpose: The conversion from Hounsfield units (HU) to stopping powers is a major source of range uncertainty in proton therapy (PT). Our contribution shows how proton radiographs (PR) acquired with a multi-layer ionization chamber in a PT center can be used for accurate patient positioning and subsequently for patient-specific optimization of the conversion from HU to stopping powers. Methods: A multi-layer ionization chamber was used to measure the integral depth-dose (IDD) of 220 MeV pencil beam spots passing through several anthropomorphic phantoms. The whole area of interest was imaged by repositioning the couch and by acquiring a 45×45 mm{sup 2} frame for each position. A rigid registration algorithm was implemented to correct the positioning error between the proton radiographs and the planning CT. After registration, the stopping power map obtained from the planning CT with the calibration curve of the treatment planning system was used together with the water equivalent thickness gained from two proton radiographs to generate a phantom-specific stopping power map. Results: Our results show that it is possible to make a registration with submillimeter accuracy from proton radiography obtained by sending beamlets separated by more than 1 mm. This was made possible by the complex shape of the IDD due to the presence of lateral heterogeneities along the path of the beam. Submillimeter positioning was still possible with a 5 mm spot spacing. Phantom specific stopping power maps obtained by minimizing the range error were cross-verified by the acquisition of an additional proton radiography where the phantom was positioned in a random but known manner. Conclusion: Our results indicate that a CT-PR registration algorithm together with range-error based optimization can be used to produce a patient-specific stopping power map. Sylvain Deffet reports financial funding of its PhD thesis by Ion Beam Applications (IBA) during the confines of the study and outside the

  4. Technical Note : A direct ray-tracing method to compute integral depth dose in pencil beam proton radiography with a multilayer ionization chamber

    NARCIS (Netherlands)

    Farace, Paolo; Righetto, Roberto; Deffet, Sylvain; Meijers, Arturs; Vander Stappen, Francois

    2016-01-01

    Purpose: To introduce a fast ray-tracing algorithm in pencil proton radiography (PR) with a multilayer ionization chamber (MLIC) for in vivo range error mapping. Methods: Pencil beam PR was obtained by delivering spots uniformly positioned in a square (45x45 mm(2) field-of-view) of 9x9 spots capable

  5. Comparison of radiography, CT and MR imaging in detection of arthropathies in patients with hemophilia

    International Nuclear Information System (INIS)

    Yu Wei; Lin Qiang; Shang Wei; Zhu Haifeng; Meng Wei; Xu Ruiyi; Zhao Yongqiang; Shi Yongsheng

    2007-01-01

    Objective: To compare MR, CT, and radiography in the detection of arthropathies in patients with hemophilia. Methods: Forty-one symptomic joint images in the 14 patients with hemophilia, aged from 11 to 24 years, were used in this study. Each joint had the examinations of radiography, CT and MR within one day. The severity of each joint was staged using conventional radiographic classification. Severe HA patients with stage 5 were excluded from the study. Imaging findings of soft tissue swelling, osteoporosis, epiphyseal overgrowth, joint erosion, cyst, joint space narrowing, bone marrow, joint effusion, hemorrhage, synovial hypertrophy, widened intercondylar notch as well as anterior and posterior cruciate ligaments (only for knee joint) were used for the all imaging comparison. Results: The 41 symptomatic joints in 14 patients with hemophilia were classified by radiographic criteria into stage 0 (n=5), stage 1 (n=7), stage 2 (n=6), stage 3 (n=8) and stage 4 (n=15). Soft tissue swelling or joint effusion was observed in 33 joints by radiographs, in 34 joints by both CT and MR. Joint erosions were demonstrated in 34 joints by MR, in 33 joints by CT and 20 joints by radiographs. Joint cysts were shown in 21 joints by MR, in 18 joints by CT and 9 joints by radiographs. Significant differences in detection of erosion and cyst were found between radiography with either CT (P 0.05). MR showed improvement for detecting more foci of both erosion and cyst than CT and radiography, and also CT showed the improvement than radiography. Bone marrow edema 14 joints, hemorrhage in 34 joints and synovial hypertrophy in 27 joints were revealed on MR images. Conclusion: MRI is superior to CT and conventional radiography in detecting the abnormal changes and should be considered as the first choice among the imaging modalities in evaluating hemophilic arthropathies. (authors)

  6. Proton radiography of dynamic electric and magnetic fields in laser-produced high-energy-density plasmas

    International Nuclear Information System (INIS)

    Li, C. K.; Seguin, F. H.; Frenje, J. A.; Manuel, M.; Casey, D.; Sinenian, N.; Petrasso, R. D.; Amendt, P. A.; Landen, O. L.; Rygg, J. R.; Town, R. P. J.; Betti, R.; Meyerhofer, D. D.; Delettrez, J.; Knauer, J. P.; Marshall, F.; Sangster, T. C.; Smalyuk, V. A.; Soures, J. M.; Shvarts, D.

    2009-01-01

    Time-gated, monoenergetic-proton radiography provides unique measurements of the electric (E) and magnetic (B) fields produced in laser-foil interactions and during the implosion of inertial-confinement-fusion capsules. These experiments resulted in the first observations of several new and important features: (1) observations of the generation, decay dynamics, and instabilities of megagauss B fields in laser-driven planar plastic foils, (2) the observation of radial E fields inside an imploding capsule, which are initially directed inward, reverse direction during deceleration, and are likely related to the evolution of the electron pressure gradient, and (3) the observation of many radial filaments with complex electromagnetic field striations in the expanding coronal plasmas surrounding the capsule. The physics behind and implications of such observed fields are discussed.

  7. TH-C-BRD-05: Reducing Proton Beam Range Uncertainty with Patient-Specific CT HU to RSP Calibrations Based On Single-Detector Proton Radiography

    Energy Technology Data Exchange (ETDEWEB)

    Doolan, P [University College London, London (United Kingdom); Massachusetts General Hospital, Boston, MA (United States); Sharp, G; Testa, M; Lu, H-M [Massachusetts General Hospital, Boston, MA (United States); Bentefour, E [Ion Beam Applications (IBA), Louvain la Neuve (Belgium); Royle, G [University College London, London (United Kingdom)

    2014-06-15

    Purpose: Beam range uncertainty in proton treatment comes primarily from converting the patient's X-ray CT (xCT) dataset to relative stopping power (RSP). Current practices use a single curve for this conversion, produced by a stoichiometric calibration based on tissue composition data for average, healthy, adult humans, but not for the individual in question. Proton radiographs produce water-equivalent path length (WEPL) maps, dependent on the RSP of tissues within the specific patient. This work investigates the use of such WEPL maps to optimize patient-specific calibration curves for reducing beam range uncertainty. Methods: The optimization procedure works on the principle of minimizing the difference between the known WEPL map, obtained from a proton radiograph, and a digitally-reconstructed WEPL map (DRWM) through an RSP dataset, by altering the calibration curve that is used to convert the xCT into an RSP dataset. DRWMs were produced with Plastimatch, an in-house developed software, and an optimization procedure was implemented in Matlab. Tests were made on a range of systems including simulated datasets with computed WEPL maps and phantoms (anthropomorphic and real biological tissue) with WEPL maps measured by single detector proton radiography. Results: For the simulated datasets, the optimizer showed excellent results. It was able to either completely eradicate or significantly reduce the root-mean-square-error (RMSE) in the WEPL for the homogeneous phantoms (to zero for individual materials or from 1.5% to 0.2% for the simultaneous optimization of multiple materials). For the heterogeneous phantom the RMSE was reduced from 1.9% to 0.3%. Conclusion: An optimization procedure has been designed to produce patient-specific calibration curves. Test results on a range of systems with different complexities and sizes have been promising for accurate beam range control in patients. This project was funded equally by the Engineering and Physical Sciences

  8. Comparison of ultrasonography with radiography for the detection of cervical esophageal foreign body

    OpenAIRE

    Reza Pourrashidi; Shervin Sharifkashani; Hashem Sharifian; Habib Mazaher; Peyman Salamati; Batool Ghorbani yekta

    2013-01-01

    Background: Detection of retained foreign bodies remains a significant problem in the emergency department. Foreign bodies can go undetected causing infectious complications ultrasonography is too inaccessible and expensive. The purpose of this study is comparison of ultrasonography with radiography for the detection of cervical esophageal foreign bodiesMethods: This cross-sectional study evaluated 58 patients referred with suspected upper esophageal foreign body in the Emergency Department, ...

  9. TU-FG-BRB-04: A New Optimization Method for Pre-Treatment Patient-Specific Stopping-Power by Combining Proton Radiography and X-Ray CT

    International Nuclear Information System (INIS)

    Collins-Fekete, C; Schulte, R; Beaulieu, L; Seco, J

    2016-01-01

    Purpose: The relative stopping power (RSP) uncertainty is the largest contributor to the range uncertainty in proton therapy. The purpose of this work is to develop a robust and systematic method that yields accurate patient specific RSPs by combining pre-treatment X-ray CT and daily proton radiography. Methods: The method is formulated as a penalized least squares optimization (PLSO) problem min(|Ax-B|). The matrix A represents the cumulative path-length crossed in each material computed by calculating proton trajectories through the X-ray CT. The material RSPs are denoted by x and B is the pRad, expressed as water equivalent thickness. The equation is solved using a convex-conic optimizer. Geant4 simulations were made to assess the feasibility of the method. RSP extracted from the Geant4 materials were used as a reference and the clinical HU-RSP curve as a comparison. The PLSO was first tested on a Gammex RMI-467 phantom. Then, anthropomorphic phantoms of the head, pelvis and lung were studied and resulting RSPs were evaluated. A pencil beam was generated in each phantom to evaluate the proton range accuracy achievable by using the optimized RSPs. Finally, experimental data of a pediatric head phantom (CIRS) were acquired using a recently completed experimental pCT scanner. Results: Numerical simulations showed precise RSP (<0.75%) for Gammex materials except low-density lung (LN-300) (1.2%). Accurate RSP have been obtained for the head (µ=−0.10%, 1.5σ=1.12%), lung (µ=−0.33, 1.5σ=1.02%) and pelvis anthropomorphic phantoms (µ=0.12, 1.5σ=0,99%). The range precision has been improved with an average R80 difference to the reference (µ±1.5σ) of −0.20±0.35%, −0.47±0.92% and −0.06±0.17% in the head, lung and pelvis phantoms respectively, compared to the 3.5% clinical margin. Experimental HU-RSP curve have been produced on the CIRS pediatric head. Conclusion: The proposed PLSO with prior knowledge X-ray CT shows promising potential (R80 σ<1.0% over

  10. Proton radiography of intense-laser-irradiated wire-attached cone targets

    International Nuclear Information System (INIS)

    Yabuuchi, T.; Sawada, H.; Bartal, T.; Beg, F.N.; Batani, D.; Gizzi, L.A.; Key, M.H.; Mackinnon, A.J.; McLean, H.S.; Patel, P.K.; Norreys, P.A.; Spindloe, C.; Stephens, R.B.; Wei, M.S.; Theobald, W.

    2011-01-01

    Measurements of extreme electrostatic and magnetic fields are of interest for the study of high-energy-density plasmas. Results of proton deflectometry of cone-wire targets that are of interest to fast-ignition inertial confinement fusion are presented. (authors)

  11. Comparison of ultrasonography with radiography for the detection of cervical esophageal foreign body

    Directory of Open Access Journals (Sweden)

    Reza Pourrashidi

    2013-07-01

    Full Text Available Background: Detection of retained foreign bodies remains a significant problem in the emergency department. Foreign bodies can go undetected causing infectious complications ultrasonography is too inaccessible and expensive. The purpose of this study is comparison of ultrasonography with radiography for the detection of cervical esophageal foreign bodiesMethods: This cross-sectional study evaluated 58 patients referred with suspected upper esophageal foreign body in the Emergency Department, Amir Alam. Patients were evaluated with ultrasonography and x-ray. After surgical exploration, different type of foreign bodies were recorded. The SPSS statistical software was used for analysis. For applicable efficacy outcome measures, a Spearman correlation was used. Differences were significant when P<0.05. All values were expressed as the frequency and present.Results: Fifty eight patients were studied. 25 patients (43.4% were male and 31 patients (56.9% were female, in 28 (48.2% patients foreign bodies were detected in radiography. 30 patients (51.8% were not recorded in techniqe. It was found in patients 22 (78.6% organic body, and six cases (21.4% non-organic body. radiographic outcomes in patients with foreign bodies were positive in 26 patients (92.9% and in two patients (7.1% were negative. Ultrasound results were positive in 27 patients (96.4% and in one patient (3.6% were negative. Association of ultrasound and radiography results were significant in patients with foreign body (Spearman correlation=0.896, P=0.001 Kappa=0.890.Conclusion: These reports suggest that result of ultrasound with radiography for the detection foreign bodies in cervical esophagus have good agreement. The use of ultrasonography in the emergency department to detect and eventually remove foreign bodies by emergency physicians is an important issue because there is not always an ultrasound technologist or radiologist available.

  12. Comparison of proton and photon dose distributions

    International Nuclear Information System (INIS)

    Goitein, Michael

    1995-01-01

    Recently, there has been considerable work, as yet largely theoretical, in developing ways to improve the dose distributions which can be achieved with x-rays. Foremost among these developments are the use of non-coplanar beam directions, the use of intensity-modulated beams, and the implementation of computer-controlled delivery of complex plans using new beam modifiers such as multi-leaf collimators and beam scanners. One way of improving the dose distributions which have been achieved with conventional radiations is to use protons, with their quite different physical characteristics but very similar radiobiological properties as compared with supervoltage x-rays. Some substantial experience has been gained in the use of protons which has confirmed clinically that better results have been obtained as a result of their better dose distributions. Indeed, it is fair to say that the advantages which protons have demonstrated are, in large part, responsible for the renewed interest in improving the dose distributions from all radiation modalities. So much better are the dose distributions which the new techniques, mentioned above, offer that there is the impression that, with their use, photons can deliver dose distributions as good as can be obtained with protons. In this paper, the extent of the possible improvement will be discussed. It will be suggested that the integral dose is relatively little affected by the treatment technique - so that the lower normal tissue doses which the new approaches offer is almost always at the price of delivering dose to a larger volume. Protons can be matched pencil beam for pencil beam with photons - and then almost always deliver substantially less dose outside the target volume. Ultimately, the clinical importance of the differences will have to decided by clinical trial

  13. Assessment of vertebral osteopenia. Comparison of spinal radiography and dual-photon absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Kroelner, B.; Berthelsen, B.; Nielsen, S.P. (Frederiksborg County Hospital, Hilleroed, Denmark)

    1982-01-01

    A comparison of radiographic morphology and dual-photon (/sup 153/Gd) absorptiometry was carried out in 132 women. Films of the lumbar spine were graded for osteopenia, spondylosis, and calcification of the abdominal aorta according to definite morphologic criteria. The radiographic grade of osteopenia and the bone mineral content of the 2nd, 3rd, and 4th lumbar vertebrae showed a highly significant inverse correlation. However, the mineral content at each radiographic grade of osteopenia differed considerably. Disproportionately high levels occurred in patients with spondylosis and severe calcification of the abdominal aorta. Spinal radiography and dual-photon absorptiometry must be regarded as complementary rather than alternative diagnostic procedures in clinical practice.

  14. Comparison of conventional panoramic radiography and panoramic digital subtraction radiography in detection of simulated lesions of mandibular condyle

    Directory of Open Access Journals (Sweden)

    Panjnoush M.

    2008-12-01

    Full Text Available "n  "nBackground and Aim: Digital subtraction Radiography (DSR is a method of accurate assessing condylar head changes. several studies have been carried out in applying DSR in dentistry, however there is a few number of studies in efficacy of DSR method in assesment of condylar head changes, The aim of this study was to compare panoramic radiography and DSR detecting simulated lesions of the mandibular condyl. "nMaterials and Methods: this was a process reaserch study, in which two dry human skulls with no obvious temporomandibular joint pathology were used. Osteophytic lesions were simulated using three sizes of bone chips that were placed on the medial portion of anterior and superolateral aspects of the condyle. Osteolytic lesions were simulated making 1 and 2 mm holes using round burr in the central portion of anterior aspect and Lateral pole of the condyle. Panoramic radiographs were prepared with and without the lesions in place. These paired radiographs were digitized and digital- subtraction images of the original panoramic images were obtained. Eight observers evaluated 155 images of each modality for the presence or absence and the type of simulated lesions of the mandibular condyle. Sensitivity, specificity, reliability and measure of agreement were analyzed using kappa test and crossed tables and qualitative variables were assess by chi-square and fisher's Exact test. "nResults: Specificity of panoramic and DSR methods were 15.4% and 66.7% respectively. Sensitivity of panoramic and DSR methods were 61.1% and 80.6% for osteophytic lesions and 37.5% and 83.3% for Osteolytic lesions. The percentage of correct decisions made in DSR method was significantly more than conventional panoramic method (82.6% vs 41.9% (p<0.0001. "nConclusion: Based on the results of this study digital subtraction technique was significantly more accurate than the panoramic radiographs in detection of simulated lesions of the mandibular condyle.

  15. Comparison of Diagnostic Performance of Semi-Quantitative Knee Ultrasound and Knee Radiography with MRI: Oulu Knee Osteoarthritis Study

    Science.gov (United States)

    Podlipská, Jana; Guermazi, Ali; Lehenkari, Petri; Niinimäki, Jaakko; Roemer, Frank W.; Arokoski, Jari P.; Kaukinen, Päivi; Liukkonen, Esa; Lammentausta, Eveliina; Nieminen, Miika T.; Tervonen, Osmo; Koski, Juhani M.; Saarakkala, Simo

    2016-01-01

    Osteoarthritis (OA) is a common degenerative musculoskeletal disease highly prevalent in aging societies worldwide. Traditionally, knee OA is diagnosed using conventional radiography. However, structural changes of articular cartilage or menisci cannot be directly evaluated using this method. On the other hand, ultrasound is a promising tool able to provide direct information on soft tissue degeneration. The aim of our study was to systematically determine the site-specific diagnostic performance of semi-quantitative ultrasound grading of knee femoral articular cartilage, osteophytes and meniscal extrusion, and of radiographic assessment of joint space narrowing and osteophytes, using MRI as a reference standard. Eighty asymptomatic and 79 symptomatic subjects with mean age of 57.7 years were included in the study. Ultrasound performed best in the assessment of femoral medial and lateral osteophytes, and medial meniscal extrusion. In comparison to radiography, ultrasound performed better or at least equally well in identification of tibio-femoral osteophytes, medial meniscal extrusion and medial femoral cartilage morphological degeneration. Ultrasound provides relevant additional diagnostic information on tissue-specific morphological changes not depicted by conventional radiography. Consequently, the use of ultrasound as a complementary imaging tool along with radiography may enable more accurate and cost-effective diagnostics of knee osteoarthritis at the primary healthcare level. PMID:26926836

  16. Selenium-based digital radiography of the cervical spine. Comparison with screen-film radiography for the depiction of anatomic details

    International Nuclear Information System (INIS)

    Ludwig, K.; Diederich, S.; Wormanns, D.; Link, T.M.; Lenzen, H.; Heindel, W.

    2002-01-01

    Purpose: To compare selenium-based digital radiography with conventional screen-film radiography of the cervical spine. Materials and Methods: In a prospective study X-ray images of the cervical spine were obtained in 25 patients using selenium-based digital radiography and conventional screen-film radiography. All images were clinically indicated. Selenium-based digital radiography and conventional screen-film radiography were used in a randomized order. Four radiologists independently evaluated all 50 examinations for the visibility of 76 anatomic details according to a five-level confidence scale (1=not visible, 5=very good visibility). From the evaluation of these anatomic details scores for the upper and middle cervical spine, the cervicothoracic junction and the cervical soft tissues were calculated. The scores for selenium-based digital radiography and conventional screen-film radiography were compared using Wilcoxon's signed rank test. Results: From a total of 15,200 observations (608 per patient) the following scores were calculated for selenium-based digital radiography and for screen-film radiography, respectively: Upper cervical spine 3.88 and 3.94; middle cervical spine 4.60 and 4.48; cervico-thoracic junction 3.64 and 2.62; cervical soft tissue 4.47 and 3.46. The differences between the last two scores were statistically significant (p [de

  17. Comparison of proton-proton and proton-antiproton scattering at very high energies

    International Nuclear Information System (INIS)

    Gauron, P.; Nicolescu, B.; Univ. Pierre et Marie Curie, 75 - Paris; Leader, E.

    1985-09-01

    The ISR results on the differential cross-sections for pp and anti-pp show unambiguously that the crossing-odd amplitude is still important at very high energies. Comparison of ISR and CERN collider anti-pp data suggests that the crossing-odd amplitude is growing maximally fast with energy. We explore the phenomenological consequences of such a ''maximal odderon'' behaviour at TeV energies

  18. SU-F-J-201: Validation Study of Proton Radiography Against CT Data for Quantitative Imaging of Anatomical Changes in Head and Neck Patients

    International Nuclear Information System (INIS)

    Hammi, A; Weber, D; Lomax, A

    2016-01-01

    Purpose: In clinical pencil-beam-scanned (PBS) proton therapy, the advantage of the characteristic sharp dose fall-off after the Bragg Peak (BP) becomes a disadvantage if the BP positions of a plan’s constituent pencil beams are shifted, eg.due to anatomical changes. Thus, for fractionated PBS proton therapy, accurate knowledge of the water equivalent path length (WEPL) of the traversed anatomy is critical. In this work we investigate the feasibility of using 2D proton range maps (proton radiography, PR) with the active-scanning gantry at PSI. Methods: We simulated our approach using Monte Carlo methods (MC) to simulate proton beam interactions in patients using clinical imaging data. We selected six head and neck cases having significant anatomical changes detected in per-treatment CTs.PRs (two at 0°/90°) were generated from MC simulations of low-dose pencil beams at 230MeV. Each beam’s residual depth-dose was propagated through the patient geometry (from CT) and detected on exiting the patient anatomy in an ideal depth-resolved detector (eg. range telescope). Firstly, to validate the technique, proton radiographs were compared to the ground truth, which was the WEPL from ray-tracing in the patient CT at the pencil beam location. Secondly, WEPL difference maps (per-treatment – planning imaging timepoints) were then generated to locate the anatomical changes, both in the CT (ground truth) and in the PRs. Binomial classification was performed to evaluate the efficacy of the technique relative to CT. Results: Over the projections simulated over all six patients, 70%, 79% and 95% of the grid points agreed with the ground truth proton range to within ±0.5%, ±1%, and ±3% respectively. The sensitivity, specificity, precision and accuracy were high (mean±1σ, 83±8%, 87±13%, 95±10%, 83±7% respectively). Conclusion: We show that proton-based radiographic images can accurately monitor patient positioning and in vivo range verification, while providing

  19. A comparison of digital radiography systems in terms of effective detective quantum efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Bertolini, Marco; Nitrosi, Andrea; Rivetti, Stefano; Lanconelli, Nico; Pattacini, Pierpaolo; Ginocchi, Vladimiro; Iori, Mauro [Department of Advanced Technology, Medical Physics Unit, Azienda Ospedaliera ASMN, Istituto di Ricovero e Cura a Carattere Scientifico, Reggio Emilia 42123 (Italy); Fisica Medica, Ospedale di Sassuolo S.p.A., Modena 41049 (Italy); Alma Mater Studiorum, Physics Department, University of Bologna, Bologna 40127 (Italy); Department of Diagnostic Imaging, Radiology Unit, Azienda Ospedaliera ASMN, Istituto di Ricovero e Cura a Carattere Scientifico, Reggio Emilia 42123 (Italy); Department of Diagnostic Imaging, Radiology Unit, Azienda USL, Reggio Emilia 42122 (Italy); Department of Advanced Technology, Medical Physics Unit, Azienda Ospedaliera ASMN, Istituto di Ricovero e Cura a Carattere Scientifico, Reggio Emilia 42123 (Italy)

    2012-05-15

    Purpose: The purpose of this study is to compare digital radiography systems using the metric effective detective quantum efficiency (eDQE), which better reflects digital radiography imaging system performance under clinical operating conditions, in comparison with conventional metrics such as modulation transfer function (MTF), normalized noise power spectra (NNPS), and detective quantum efficiency (DQE). Methods: The eDQE was computed by the calculation of the MTF, the NNPS, the phantom attenuation and scatter, and estimation of x-ray flux. The physical characterization of the systems was obtained with the standard beam conditions RQA5 and RQA9, using the PA Chest phantom proposed by AAPM Report no. 31 simulating the attenuation and scatter characteristics of the adult human thorax. The MTF (eMTF) was measured by using an edge test placed at the frontal surface of the phantom, the NNPS (eNNPS) was calculated from images of the phantom acquired at three different exposure levels covering the operating range of the system (E{sub 0}, which is the exposure at which a system is normally operated, 1/3 E{sub 0}, and 3 E0), and scatter measurements were assessed by using a beam-stop technique. The integral of DQE (IDQE) and eDQE (IeDQE) was calculated over the whole spatial frequency range. Results: The eMTF results demonstrate degradation due to magnification and the presence of scattered radiation. The eNNPS was influenced by the grid presence, and in some systems, it contained structured noise. At typical clinical exposure levels, the magnitude of eDQE(0) with respect to DQE(0) at RQA9 beam conditions was 13%, 17%, 16%, 36%, and 24%, respectively, for Carestream DRX-1, Carestream DRX-1C, Carestream Direct View CR975, Philips Digital Diagnost VM, and GE Revolution XR/d. These results were confirmed by the ratio of IeDQE and IDQE in the same conditions. Conclusions: The authors confirm the robustness and reproducibility of the eDQE method. As expected, the DR systems

  20. A comparison of digital radiography systems in terms of effective detective quantum efficiency

    International Nuclear Information System (INIS)

    Bertolini, Marco; Nitrosi, Andrea; Rivetti, Stefano; Lanconelli, Nico; Pattacini, Pierpaolo; Ginocchi, Vladimiro; Iori, Mauro

    2012-01-01

    Purpose: The purpose of this study is to compare digital radiography systems using the metric effective detective quantum efficiency (eDQE), which better reflects digital radiography imaging system performance under clinical operating conditions, in comparison with conventional metrics such as modulation transfer function (MTF), normalized noise power spectra (NNPS), and detective quantum efficiency (DQE). Methods: The eDQE was computed by the calculation of the MTF, the NNPS, the phantom attenuation and scatter, and estimation of x-ray flux. The physical characterization of the systems was obtained with the standard beam conditions RQA5 and RQA9, using the PA Chest phantom proposed by AAPM Report no. 31 simulating the attenuation and scatter characteristics of the adult human thorax. The MTF (eMTF) was measured by using an edge test placed at the frontal surface of the phantom, the NNPS (eNNPS) was calculated from images of the phantom acquired at three different exposure levels covering the operating range of the system (E 0 , which is the exposure at which a system is normally operated, 1/3 E 0 , and 3 E0), and scatter measurements were assessed by using a beam-stop technique. The integral of DQE (IDQE) and eDQE (IeDQE) was calculated over the whole spatial frequency range. Results: The eMTF results demonstrate degradation due to magnification and the presence of scattered radiation. The eNNPS was influenced by the grid presence, and in some systems, it contained structured noise. At typical clinical exposure levels, the magnitude of eDQE(0) with respect to DQE(0) at RQA9 beam conditions was 13%, 17%, 16%, 36%, and 24%, respectively, for Carestream DRX-1, Carestream DRX-1C, Carestream Direct View CR975, Philips Digital Diagnost VM, and GE Revolution XR/d. These results were confirmed by the ratio of IeDQE and IDQE in the same conditions. Conclusions: The authors confirm the robustness and reproducibility of the eDQE method. As expected, the DR systems performed

  1. Comparison of computed tomography and radiography for detecting changes induced by malignant nasal neoplasia in dogs

    International Nuclear Information System (INIS)

    Park, R.D.; Beck, E.R.; LeCouteur, R.A.

    1992-01-01

    The ability of computed tomography and radiography to detect changes associated with nasal neoplasia was compared in dogs. Eighteen areas or anatomic structures were evaluated in 21 dogs for changes indicative of neoplasia. Computed tomography was superior (P < or = 0.05) to radiography for detecting changes in 14 of 18 areas. Radiography was not superior for detecting changes in any structure or area. Computed tomography reveals vital information not always detected radiographically to assist in providing a prognosis and in planning treatment for nasal neoplasms in dogs

  2. Retrospective comparison of abdominal ultrasonography and radiography in the investigation of feline abdominal disease

    Science.gov (United States)

    Won, Wylen Wade; Sharma, Ajay; Wu, Wenbo

    2015-01-01

    Abdominal radiography and ultrasonography are commonly used as part of the initial diagnostic plan for cats with nonspecific signs of abdominal disease. This retrospective study compared the clinical usefulness of abdominal radiography and ultrasonography in 105 feline patients with signs of abdominal disease. The final diagnosis was determined more commonly with ultrasonography (59%) compared to radiography (25.7%). Ultrasonography was also able to provide additional clinically relevant information in 76% of cases, and changed or refined the diagnosis in 47% of cases. Based on these findings, ultrasonography may be sufficient as an initial diagnostic test for the investigation of feline abdominal disease. PMID:26483582

  3. Moderator/collimator for a proton/deuteron linac to produce a high-intensity, high-quality thermal neutron beam for neutron radiography

    International Nuclear Information System (INIS)

    Singleterry, R.C. Jr.; Imel, G.R.; McMichael, G.E.

    1995-01-01

    Reactor based high resolution neutron radiography facilities are able to deliver a well-collimated (L/D ≥100) thermal flux of 10 6 n/cm 2 ·sec to an image plane. This is well in excess of that achievable with the present accelerator based systems such as sealed tube D-T sources, Van der Graaff's, small cyclotrons, or low duty factor linacs. However, continuous wave linacs can accelerate tens of milliamperes of protons to 2.5 to 4 MeV. The MCNP code has been used to analyze target/moderator configurations that could be used with Argonne's Continuous Wave Linac (ACWL). These analyses have shown that ACWL could be modified to generate a neutron beam that has a high intensity and is of high quality

  4. Videofluoroscopy of the pharynx and esophagus in patients with globus pharyngis. Comparison with static radiography

    International Nuclear Information System (INIS)

    Schober, E.; Schima, W.; Pokieser, P.

    1995-01-01

    The symptom is associated with a multitude of pharyngoesophageal abnormalities. Our study compares the diagnostic yield of videofluoroscopy to that of static radiography in patients suffering from globus pharnygis. A total of 150 consecutive patients complaining of a lump in the throat, but without evidence of dysphagia, were studied in a standardized fashion with both methods. Videofluoroscopy combined with static radiography revealed morphological or functional abnormalities in 75% of our patients. The combination of the two methods yielded significantly more abnormalities in the pharynx and esophagus than videofluoroscopy or static radiography alone. Esophageal motor disorders, pharyngoesophageal sphincter dysfunction and pharyngeal residue of contrast material proved to be the most common abnormalities. In conclusion, videofluoroscopy combined with static radiography is mandatory in the radiological assessment of patients suffering from the globus sensation. (orig.) [de

  5. Comparison study on CNR and SNR of thoracic spine lateral radiography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Won [Dept. of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Min, Jung Whan; Lyu, Kwang Yeul [Dept. of Radiology, Shingu University, Sungnam (Korea, Republic of); Kim, Jung Min [Dept. of Radiological Science, College of Health Science, Korea University, Seoul (Korea, Republic of); Jeong, Hei Woun [Dept. of Radiological Science, Beakseok Culture University, Cheonan (Korea, Republic of); Lee, Joo Ah [Dept. of Oncology, Catholic University of Korea Incheon St.Mary,s Hospital, Incheon (Korea, Republic of); Jung, Jae Hong [Dept. of Oncology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Sung, Dong Chan [Dept. of Radiology, Dong Guk University Medical Center, Seoul (Korea, Republic of); Park, Soon Cheol [Dept. of Radiology, Kang Dong Kyung Hee University Medical Center, Seoul (Korea, Republic of)

    2013-12-15

    This study was proven for the T-spine breathing technique in lateral projection, using computer radiography (CR), charge coupled device (CCD), indirect digital radiography (IDR) and direct digital radiography (DDR). All images were evaluated and compared with CNR and SNR measured with the mean pixels and the standard deviation as setting ROI of spinous process, pedicle, vertebral body, intervertebral foramen and intervertebral disk using Image J. In experiment results of 4 type detectors, T-spine breathing technique was indicated as excellent in ROI of spinous process, pedicle, vertebral body, intervertebral foramen and intervertebral disk. As T-spine breathing technique indicated excellent images compared to the existing T-spine lateral radiography, this method would be useful for elderly patients who have difficulty in deep exhalation. This study was indicated the application possibility of T-spine breathing technique by presenting contrast to noise ratio (CNR) and signal to noise ratio (SNR) with quantitative value in 4 type detectors.

  6. Comparison between sensitivities of quality control methods using ultrasonic waves, radiography and acoustic emission for the thick welded joint testing

    International Nuclear Information System (INIS)

    Asty, Michel; Birac, Claude

    1981-09-01

    The testing of the thick welded joints of the nuclear industry is carried out by radiography and ultrasonics on completion of welding. When a fault is found, its repair requires a sometimes deep cut down to the position of the fault, then filling in of the cut by hand welding with a coated electrode. This very costly operation also involves the risk of causing new defects when building up by hand. Listening to the acoustic emission during the welding has been considered in order to seek the possibility of detecting defects when they appear, or soon after. The industrial use of this method would make an instant repair of the defective areas possible at less cost and with greater reliability. The study presented concerns the comparison between the results of the various non-destructive testing methods: radiography, ultrasonics and acoustic emission, for a thick welded joint in which the defects have been brought about [fr

  7. SU-C-207A-05: Feature Based Water Equivalent Path Length (WEPL) Determination for Proton Radiography by the Technique of Time Resolved Dose Measurement

    International Nuclear Information System (INIS)

    Zhang, R; Jee, K; Sharp, G; Flanz, J; Lu, H

    2016-01-01

    Purpose: Studies show that WEPL can be determined from modulated dose rate functions (DRF). However, the previous calibration method based on statistics of the DRF is sensitive to energy mixing of protons due to scattering through different materials (termed as range mixing here), causing inaccuracies in the determination of WEPL. This study intends to explore time-domain features of the DRF to reduce the effect of range mixing in proton radiography (pRG) by this technique. Methods: An amorphous silicon flat panel (PaxScan™ 4030CB, Varian Medical Systems, Inc., Palo Alto, CA) was placed behind phantoms to measure DRFs from a proton beam modulated by a specially designed modulator wheel. The performance of two methods, the previously used method based on the root mean square (RMS) and the new approach based on time-domain features of the DRF, are compared for retrieving WEPL and RSP from pRG of a Gammex phantom. Results: Calibration by T_8_0 (the time point for 80% of the major peak) was more robust to range mixing and produced WEPL with improved accuracy. The error of RSP was reduced from 8.2% to 1.7% for lung equivalent material, with the mean error for all other materials reduced from 1.2% to 0.7%. The mean error of the full width at half maximum (FWHM) of retrieved inserts was decreased from 25.85% to 5.89% for the RMS and T_8_0 method respectively. Monte Carlo simulations in simplified cases also demonstrated that the T_8_0 method is less sensitive to range mixing than the RMS method. Conclusion: WEPL images have been retrieved based on single flat panel measured DRFs, with inaccuracies reduced by exploiting time-domain features as the calibration parameter. The T_8_0 method is validated to be less sensitive to range mixing and can thus retrieve the WEPL values in proximity of interfaces with improved numerical and spatial accuracy for proton radiography.

  8. Tomosynthesis of the wrist and hand in patients with rheumatoid arthritis: comparison with radiography and MRI.

    Science.gov (United States)

    Aoki, Takatoshi; Fujii, Masami; Yamashita, Yoshiko; Takahashi, Hiroyuki; Oki, Hodaka; Hayashida, Yoshiko; Saito, Kazuyoshi; Tanaka, Yoshiya; Korogi, Yukunori

    2014-02-01

    The purpose of this article is to compare tomosynthesis with radiography and MRI of the wrist and hand for evaluating bone erosion in patients with rheumatoid arthritis (RA). Twenty consecutive patients with an established diagnosis of RA and five control patients were included in this study. They underwent radiography, tomosynthesis, and MRI of the bilateral hand and wrist within a week. The mean total dose of radiography and tomosynthesis was 0.13 and 0.25 mGy, respectively. MRI evaluation was performed according to the Outcome Measures in Rheumatology Clinical Trials recommendations. Bone erosion on images from the three modalities was independently reviewed by two certificated radiologists with a 4-point scale (0, normal; 1, discrete erosion; 2, tomosynthesis, and MRI were 26.5%, 36.1%, and 36.7%, respectively. Significantly more bone erosions were revealed with tomosynthesis and MRI than with radiography (p tomosynthesis. Interobserver agreement (kappa value) for bone erosion was good to excellent on tomosynthesis and MRI for all joints (0.65-1.00 and 0.68-1.00, respectively), whereas it was slight to fair on radiography for some carpal bones and bases of metacarpal bones (0.22-0.56). Tomosynthesis is superior to radiography and almost comparable to MRI for the detection of bone erosion in patients with RA.

  9. Evaluation of chest tomosynthesis for the detection of pulmonary nodules: effect of clinical experience and comparison with chest radiography

    Science.gov (United States)

    Zachrisson, Sara; Vikgren, Jenny; Svalkvist, Angelica; Johnsson, Åse A.; Boijsen, Marianne; Flinck, Agneta; Månsson, Lars Gunnar; Kheddache, Susanne; Båth, Magnus

    2009-02-01

    Chest tomosynthesis refers to the technique of collecting low-dose projections of the chest at different angles and using these projections to reconstruct section images of the chest. In this study, a comparison of chest tomosynthesis and chest radiography in the detection of pulmonary nodules was performed and the effect of clinical experience of chest tomosynthesis was evaluated. Three senior thoracic radiologists, with more than ten years of experience of chest radiology and 6 months of clinical experience of chest tomosynthesis, acted as observers in a jackknife free-response receiver operating characteristics (JAFROC-1) study, performed on 42 patients with and 47 patients without pulmonary nodules examined with both chest tomosynthesis and chest radiography. MDCT was used as reference and the total number of nodules found using MDCT was 131. To investigate the effect of additional clinical experience of chest tomosynthesis, a second reading session of the tomosynthesis images was performed one year after the initial one. The JAFROC-1 figure of merit (FOM) was used as the principal measure of detectability. In comparison with chest radiography, chest tomosynthesis performed significantly better with regard to detectability. The observer-averaged JAFROC-1 FOM was 0.61 for tomosynthesis and 0.40 for radiography, giving a statistically significant difference between the techniques of 0.21 (p<0.0001). The observer-averaged JAFROC-1 FOM of the second reading of the tomosynthesis cases was not significantly higher than that of the first reading, indicating no improvement in detectability due to additional clinical experience of tomosynthesis.

  10. New medical application: nuclear scattering radiography

    International Nuclear Information System (INIS)

    Saudinos, J.

    1977-01-01

    Nuclear scattering of 1 GeV protons is used to obtain three dimensional radiographies with a volume resolution of about 1 mm 3 . The information is different from the one given by X-ray radiographies and in particular one may get radiographies of the hydrogen included in objects. Results on a vertebral column and a 'sella turcica' are presented [fr

  11. Sci-Fri PM: Radiation Therapy, Planning, Imaging, and Special Techniques - 01: On the use of proton radiography to reduce beam range uncertainties and improve patient positioning accuracy in proton therapy

    Energy Technology Data Exchange (ETDEWEB)

    Collins-Fekete, Charles-Antoine; Beaulieu, Luc; Seco, Joao [Université Laval/ CHU de Québec, Université Laval/CHU de Québec, Massachussetts General Hospital/ Harvard Medical School (United States)

    2016-08-15

    To present two related developments of proton radiography (pRad) to minimize range uncertainty in proton therapy. The first combines a pRad with an X-ray CT to produce a patient-specific relative stopping power (RSP) map. The second aims to improve the pRad spatial resolution for accurate registration prior to the first. The enhanced-pRad can also be used in a novel proton-CT reconstruction algorithm. Monte Carlo pRad were computed from three phantoms; the Gammex, the Catphan and an anthropomorphic head. An optimized cubic-spline estimator derives the most likely path. The length crossed by the protons voxel-by-voxel was calculated by combining their estimated paths with the CT. The difference between the theoretical (length×RSP) and measured energy loss was minimized through a least squares optimization (LSO) algorithm yielding the RSP map. To increase pRad spatial resolution for registration with the CT, the phantom was discretized into voxels columns. The average column RSP was optimized to maximize the proton energy loss likelihood (MLE). Simulations showed precise RSP (<0.75%) for Gammex materials except low-density lung (<1.2%). For the head, accurate RSP were obtained (µ=−0.10%1.5σ=1.12%) and the range precision was improved (ΔR80 of −0.20±0.35%). Spatial resolution was increased in pRad (2.75 to 6.71 lp/cm) and pCT from MLE-enhanced pRad (2.83 to 5.86 lp/cm). The LSO decreases the range uncertainty (R80σ<1.0%) while the MLE-enhanced pRad spatial resolution (+244%) and is a great candidate for pCT reconstruction.

  12. COMPARISON OF THORACIC ULTRASONOGRAPHY AND RADIOGRAPHY FOR THE DETECTION OF INDUCED SMALL VOLUME PNEUMOTHORAX IN THE HORSE.

    Science.gov (United States)

    Partlow, Jessica; David, Florent; Hunt, Luanne Michelle; Relave, Fabien; Blond, Laurent; Pinilla, Manuel; Lavoie, Jean-Pierre

    2017-05-01

    Small volume pneumothorax can be challenging to diagnose in horses. The current standard method for diagnosis is standing thoracic radiography. We hypothesized that thoracic ultrasonography would be more sensitive. Objectives of this prospective, experimental study were to describe a thoracic ultrasound method for detection of small volume pneumothorax in horses and to compare results of radiography and ultrasound in a sample of horses with induced small volume pneumothorax. Six mature healthy horses were recruited for this study. For each horse, five 50 ml air boluses were sequentially introduced via a teat cannula into the pleural space. Lateral thoracic radiographs and standardized ultrasound (2D and M-mode) examinations of both hemithoraces were performed following administration of each 50 ml air bolus. Radiographs and ultrasound images/videos were analyzed for detection of pneumothorax by four independent investigators who were unaware of treatment status. Sensitivity, specificity, positive predictive values, negative predictive values, and agreement among investigators (Kappa test, κ) were calculated for radiography, 2D and M-mode ultrasound. Comparisons were made using a chi-squared exact test with significance set at P pneumothorax detection (P = 0.02 and P = 0.04, respectively). Specificity and positive predictive values were similar for all three imaging modalities (P = 1). Agreement between investigators for pneumothorax detection was excellent for 2D ultrasound (κ = 1), very good for M-mode ultrasound (κ = 0.87), and good for radiography (κ = 0.79). Findings from this experimental study supported the use of thoracic ultrasonography as a diagnostic method for detecting pneumothorax in horses. © 2017 American College of Veterinary Radiology.

  13. Sacroiliitis in Ankylosing Spondylitis: Comparison with Multidetector Row CT and Plain Radiography

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ji Youn; Joo, Kyung Bin; Choi, Byeong Kyoo; Ryu, Jeong Ah; Kim, Tae Hwan; Choi, Woo Jung [Hanyang University Hospital, Seoul (Korea, Republic of)

    2009-03-15

    The objective of our study was to compare multidetector row CT and the plain radiographs for making the diagnosis and grading the sacroiliitis that accompanies ankylosing spondylitis. We wanted to determine the role of multidetector row CT for the evaluation of the sacroilitis in patients with ankylosing spondylitis. One hundred ninety two patients with clinically suspected ankylosing spondylitis were evaluated by conventional radiography and multidetector row CT. Two musculoskeletal radiologists retrospectively analyzed the images, and they graded the sacroiliitis using the modified New York Criteria. Multidetector row CT demonstrated a significantly higher sensitivity (74.5%, 83.3%) than did plain radiography (59.9%, 66.7%) for detecting early sacroiliitis (p<0.05). Multidetector row CT showed a higher grade of sacroiliitis in 114 and 127 of 384 sacroiliac joints. Performing multidetector row CT rather than plain radiography for making the diagnoses of accompanying ankylosing spondylitis allows an early start of treatment with a subsequently improved prognosis

  14. Digital Tomosynthesis to Evaluate Fracture Healing: Prospective Comparison With Radiography and CT.

    Science.gov (United States)

    Ha, Alice S; Lee, Amie Y; Hippe, Daniel S; Chou, Shinn-Huey S; Chew, Felix S

    2015-07-01

    Radiography, currently the standard for postoperative fracture imaging, is limited by overlapping bone and hardware. Tomosynthesis has the benefit of level-by-level imaging without the disadvantages of metal artifacts, increased radiation, and higher costs of CT, the current problem-solving tool. The purpose of this study was to compare tomosynthesis with radiography for evaluating fracture healing. In a prospective study, patients within 1 year of wrist hardware fixation underwent radiography, tomosynthesis, and CT, and the images were interpreted by three readers. The diagnostic accuracy of radiology and tomosynthesis was assessed with ROC curves, and interreader agreement was assessed with Cohen kappa. Fracture scores were correlated with Disabilities of the Arm, Shoulder, and Hand (DASH) and pain scores. The study participants were 49 patients with 51 fractures. The most common fracture sites were distal radius (43%), scaphoid (18%), and metacarpals (18%). Rates of cortex obscuration by hardware were 2% for CT, 8% for tomosynthesis, and 15% for radiography (p tomosynthesis than with radiography (AUC, 0.84 vs 0.76, p = 0.01). Inter-reader agreement was moderate for both radiography and tomosynthesis (κ = 0.44 vs 0.55, p = 0.051). There was no significant correlation between fracture scores and DASH scores. There was significant correlation between reported pain levels and both tomosynthesis (r = 0.28, p = 0.03) and CT (r = 0.29, p = 0.04) fracture scores. Tomosynthesis provides diagnostic information superior to that of ra diography in postoperative evaluation of wrist fractures with lower cost and radiation than CT and should be considered in fracture follow-up imaging of other bones.

  15. Measurements of proton strength functions and comparisons with theory

    International Nuclear Information System (INIS)

    Arai, E.; Ozawa, Y.

    1986-01-01

    Using a high-resolution proton beam of the Tokyo Institute of Technology Van de Graaff, precise measurements of elastic and inelastic scattering cross sections have been performed in the past 15 years. By directly observing individual proton resonances, their spins, parities and proton decay widths were deduced. From these experiments we have evaluated (1) proton strength functions in terms of target mass number and of incident proton energy and (2) Coulomb matrix elements for split analogue resonances. (orig.)

  16. The radiologic finding in pneumomediastinum. Value of conventional radiography and comparison with computerized tomography

    International Nuclear Information System (INIS)

    Martin, M.F.; Hlawatsch, A.; Heussel, C.P.; Schweden, F.; Kauczor, H.U.

    1997-01-01

    Pneumomediastinum, or mediastinal emphysema, may be difficult to demonstrate and is not always easy to differentiate from pneumothorax and pneumopericardium by conventional radiography, especially in severely ill patients. In this article, we evaluate the sensitivity of plain films in detecting pneumomediastinum, and describe the conventional radiography and computerized tomography (CT) findings associated with this entity. The etiology and CT findings in 24 patients who had been diagnosed as having pneumomediastinum by CT were reviewed. Conventional radiographs were available for review in 19 of these cases. Radiographic and CT findings were retrospectively compared, using CT as reference technique. We looked for abnormal mediastinal air collections and their location, as well as pathologic findings such as pneumothorax or pneumopericardium. Classical radiographic signs were also evaluated. Conventional radiography showed mediastinal air in 17 patients (89,5%) and classical radiographic signs were observed in 13 (68,4%). The results of the comparative study of plain films and CT revealed the following sites of mediastinal air: superior mediastinum (9/15), anterior mediastinum (14/19), middle mediastinum (7/12) and posterior mediastinum (4/14). The incidences of pneumothorax (7/12) and pneumopericardium (1/4) were also recorded. The comparative study of conventional radiography and CT demonstrated that Ct is a more reliable technique for determining the diagnosis, location and extent of pneumomediastinum and differentiating it from pneumothorax and pneumopericardium, especially in severely ill patients. Therefore, CT is recommended in patients with evident clinical suspicion of pneumomediastinum. (Author) 23 refs

  17. Computed and conventional chest radiography: a comparison of image quality and radiation dose

    International Nuclear Information System (INIS)

    Ramli, K.; Abdullah, B.J.J.; Ng, K-H.; Hussain, A.F.; Mahmud, R.

    2005-01-01

    The aim of this study was to compare the image quality and entrance skin dose (ESD) for film-screen and computed chest radiography. Analysis of the image quality and dose on chest radiography was carried out on a conventional X-ray unit using film-screen, storage phosphor plates and selenium drum direct chest radiography. For each receptor, ESD was measured in 60 patients using thermoluminescent dosemeters. Images were printed on 35 x 43 cm films. Image quality was assessed subjectively by evaluation of anatomic features and estimation of the image quality, following the guidelines established by the protocols of the Commission of the European Communities. There was no statistically significant difference noted between the computed and conventional images (Wilcoxon rank sum test, P>0.05). Imaging of the mediastinum and peripheral lung structures were better visualized with the storage phosphor and selenium drum technique than with the film-screen combination. The patients' mean ESD for chest radiography using the storage phosphor, film-screen combination and selenium drum was 0.20, 0.20 and 0.25 mGy, respectively, with no statistically significant difference with P > 0.05 (χ 2 tests) Copyright (2005) Blackwell Publishing Asia Pty Ltd

  18. Comparison between film-screen and computed radiography systems in Brazilian mammography

    International Nuclear Information System (INIS)

    Vieira, L.A.; Oliveira, J.R.; Carvalho, L.A.P.; César, A.C.Z.; Nogueira, M.S.

    2015-01-01

    Since 2004 the Public Health Office of the State of Minas Gerais in Brazil has established the Image Quality Control Program in Mammography. It evaluates the image quality based on an accredited phantom of the Brazilian College of Radiology (CBR). This phantom follows international standards such as masses, specks, fibers, contrast details and spatial resolution. The contrast index (CI) is accessed through optical density (OD) measurements. Although OD is defined under film-screen (FS) scope, among all accessible mammographic systems under the health office surveillance, almost 80% are computed radiography (CR) based. A necessity to adapt the protocol has emerged to consider OD as a conformity parameter. Objective: To verify the OD accessibility under CR´s printed out films and the feasibility to calculate contrast index, in comparison with FS´s. Results: A total of 56 images were evaluated with three different CBR phantoms. They were equally divided into FS and CR systems and a densitometer was used to read out their OD values. The correlation between their contrast-to-noise ratio (CNR) was found to be in the order of 0.77 (±0.14). The samples were not significantly different (inside 5% incertitude) for every phantom. The CNR correlation coefficient was 0.871. For OD, correlation coefficient was 0.989 and a log-fit function has shown good agreement with detector response. The OD-normalized standard deviation difference between CR and FS for every different phantom was 36.6%, 2.8% and 20.2%. A CI range for CR´s lying between 0.13 and 0.69 was found. Conclusions: Different phantoms were successfully tested in both CR and FS to evaluate the feasibility in use contrast index as a conformity parameter since their correlations are strictly related to calibration curve, as provided by phantom manufacturer. The relative CR-FS OD σ-difference provides a spreading indicator, where the first and last phantoms are considerably out of expectation. Such differences are

  19. Radiography - A conceptual approach

    Energy Technology Data Exchange (ETDEWEB)

    Ahonen, Sanna-Mari [Department of Nursing Science and Health Administration, University of Oulu, P.O. Box 5000, FIN-90014 (Finland)], E-mail: sanna-mari.ahonen@oulu.fi

    2008-11-15

    Aim: The purpose of this article is to describe interdisciplinary comparison of the attributes of the concept of radiography in health sciences, physics and technology on the grounds of concept analysis. Background: The concept of radiography is widely used in health sciences, physics and technology. However, the content of the concept may vary. In order to clarify the concept of radiography, the concept must be systematically examined and defined in linguistic form. Method: The concept of radiography was analysed by using the evolutionary method of concept analysis. The data were collected through discretionary sampling and consisted of literature and Internet pages. Qualitative content analysis was employed for analysing the data. Findings: As a result of concept analysis, the concept of radiography in health sciences was determined as expertise of radiographers in the use of radiation, which is dual, dynamic, social and situation-related in nature, and typically based on versatile synthesis. Regarding the attributes identified, the concept of radiography has both similarities and differences between health sciences, physics and technology. Conclusions: The concept of radiography was found to be more abstract, wider, more complex and more radiographer-centred in health sciences than in other disciplines. The content of the concept of radiography seems to vary according to the discipline.

  20. Radiography - A conceptual approach

    International Nuclear Information System (INIS)

    Ahonen, Sanna-Mari

    2008-01-01

    Aim: The purpose of this article is to describe interdisciplinary comparison of the attributes of the concept of radiography in health sciences, physics and technology on the grounds of concept analysis. Background: The concept of radiography is widely used in health sciences, physics and technology. However, the content of the concept may vary. In order to clarify the concept of radiography, the concept must be systematically examined and defined in linguistic form. Method: The concept of radiography was analysed by using the evolutionary method of concept analysis. The data were collected through discretionary sampling and consisted of literature and Internet pages. Qualitative content analysis was employed for analysing the data. Findings: As a result of concept analysis, the concept of radiography in health sciences was determined as expertise of radiographers in the use of radiation, which is dual, dynamic, social and situation-related in nature, and typically based on versatile synthesis. Regarding the attributes identified, the concept of radiography has both similarities and differences between health sciences, physics and technology. Conclusions: The concept of radiography was found to be more abstract, wider, more complex and more radiographer-centred in health sciences than in other disciplines. The content of the concept of radiography seems to vary according to the discipline

  1. Comparison of the Accuracy of Root ZX and Novapex with Radiography: an in Vivo Study

    Directory of Open Access Journals (Sweden)

    Amir Mohamad Mahabadi

    2012-02-01

    Full Text Available Background and Aims: Working length determination and remaining this length is of great importance in root canal therapy. Recently, electronic apex locators are being used to determine working length and decrease the number of radiographs. The purpose of this study was to compare the sensitivity of Root ZX and Novapex electronic apex locators with radiography in a clinical study. Materials and Methods: In this study, 73 single-canalled teeth of the patients referred to the endodontic department of the Yazd Dental School were evaluated. The access cavity was prepared and working length of the root canals were measured by using the apex locators: Root ZX and Novapex. The file was placed in the root canal and a periapical radiograph was taken using parallel technique. The working lengths obtained by apex locators were recorded and compared with those of radiographs. The data were analyzed by Pearsons correlation coefficient, Wilcoxon test and paired t-test. Results: The exact measurement without any fault was 46.6% for Root ZX and 20.5% for Novapex compared to radiography. In the range of 0.5 mm fault, the results were 91.8% for Root ZX and 64.4% for Novapex compared to radiographic measurements. The difference between the average of the measured lengths by Root ZX and radiography was not significant (P=0.17. On the other hand, the results showed significant difference between the average of the measured lengths by Novapex and radiography (P=0.017. The difference between two apex locators was not significant (P=0.061. Conclusion: Root ZX and Novapex with high accuracy are useful for determining working length of the root canals in pregnant patients with special anatomic conditions and patients with muscle disharmony. Therefore, the use of these apex locators combined with radiography is recommended in root canal treatment.

  2. Assessment of medial elbow laxity by gravity stress radiography: comparison of valgus stress radiography with gravity and a Telos stress device.

    Science.gov (United States)

    Harada, Mikio; Takahara, Masatoshi; Maruyama, Masahiro; Nemoto, Tadanobu; Koseki, Kazuhiko; Kato, Yoshihiro

    2014-04-01

    Valgus instability was reported to be higher with the elbow in 60° of flexion, rather than in 30° of flexion, although there are no studies using valgus stress radiography by gravity (gravity radiography) with the elbow in 60° of flexion. Fifty-seven patients with medial elbow pain participated. For both elbows, valgus stress radiography by use of a Telos device (Telos radiography) and gravity radiography, with the elbow in 60° of flexion, were performed for the assessment of medial elbow laxity. In both radiographs, the medial elbow joint space (MJS) on the affected side was compared with that on the opposite side, and the increase in the MJS on the affected side was assessed. For the Telos radiographs, the mean MJS was 4.7 mm on the affected side and 4.0 mm on the opposite side, with the mean increase in the MJS on the affected side being 0.7 mm. For the gravity radiographs, the mean MJS was 5.0 mm on the affected side and 4.2 mm on the opposite side, with the mean increase in the MJS on the affected side being 0.8 mm. There were significant correlations between the Telos and gravity radiographs in the MJS on the affected side, the MJS on the opposite side, and the increase in the MJS on the affected side (respectively, P gravity radiographs. Gravity radiography is useful for assessment of medial elbow laxity, similar to Telos radiography. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  3. Computer radiography - indirect digital radiography

    International Nuclear Information System (INIS)

    Jezierski, G.

    2008-01-01

    Implementation of the new European standards for industrial radiography with the use of storage phosphor imaging plates will result in the arousing of interest among numerous laboratories in non-destructive testing with application of the new method of testing to replace conventional radiography used so far, i.e. film radiography. Computer radiography is quite commonly used for medical radiography, where the fundamental problem consists in reduction of the radiation dose during the examination of a patient. However, it must be kept in mind that industrial applications have a little bit different requirements when compared with medical radiography. The article describes only new method for radiographic testing. (author)

  4. Charged Particle Radiography

    International Nuclear Information System (INIS)

    Morris, Chris

    2004-01-01

    The Coulomb multiple scattering of charged particles as they pass through material allows them to be used as a radiographic probe. This forms the basis for a new kind of radiography that is finding application where conventional x-ray radiography is limited by flux or backgrounds. Charged-particle radiography is providing a versatile new probe that has advantages over conventional x-ray radiography for some unique application. Proton radiography has been used to make quantitative motion pictures of high explosive driven experiments and proves to be of great value for radiographing experiments that mock up nuclear weapon primaries for stockpile certification. By taking advantage of magnetic lens to magnify images and by using the very bright beams that can be made with electrons, charged-particle radiography may be useful for studying the fine spatial detail and very fast motion in laser driven implosion experiments at the National Ignition Facility. Finally, radiographs can be made using cosmic-ray muons for searching vehicles and cargo containers for surreptitious cargo of high z materials such as uranium or plutonium.

  5. Comparison of Radiography and Ultrasonography for Diagnosis of Diaphragmatic Hernia in Bovines

    Directory of Open Access Journals (Sweden)

    Hakim Athar

    2010-01-01

    Full Text Available The present study was conducted on 101 animals suffering from thoracoabdominal disorders; out of which twenty seven animals (twenty six buffaloes and one cow were diagnosed with diaphragmatic hernia based on clinical signs, radiography, ultrasonography, and left flank laparorumenotomy. Radiography alone confirmed diaphragmatic hernia in 18 cases (66.67% with a sac-like structure cranial to the diaphragm. In 15 animals the sac contained metallic densities while in three cases a sac-like structure with no metallic densities was present. Ultrasonography was helpful in confirming diaphragmatic hernia in 23 cases (85.18% and ultrasonographically reticular motility was evident at the level of 4th/5th intercostal space in all the animals. B+M mode ultrasonography was used for the first time for diagnosis of diaphragmatic hernia in bovines and the results suggested that ultrasonography was a reliable diagnostic modality for diaphragmatic hernia in bovines.

  6. Comparison of radiography and ultrasonography for diagnosing small-intestinal mechanical obstruction in vomiting dogs.

    Science.gov (United States)

    Sharma, Ajay; Thompson, Margret S; Scrivani, Peter V; Dykes, Nathan L; Yeager, Amy E; Freer, Sean R; Erb, Hollis N

    2011-01-01

    A cross-sectional study was performed on acutely vomiting dogs to compare the accuracy of radiography and ultrasonography for the diagnosis of small-intestinal mechanical obstruction and to describe several radiographic and ultrasonographic signs to identify their contribution to the final diagnosis. The sample population consisted of 82 adult dogs and small-intestinal obstruction by foreign body was confirmed in 27/82 (33%) dogs by surgery or necropsy. Radiography produced a definitive result (obstructed or not obstructed) in 58/82 (70%) of dogs; ultrasonography produced a definitive result in 80/82 (97%) of dogs. On radiographs, a diagnosis of obstruction was based on detection of segmental small-intestinal dilatation, plication, or detection of a foreign body. Approximately 30% (8/27) of obstructed dogs did not have radiographic signs of segmental small-intestinal dilatation, of which 50% (4/8) were due to linear foreign bodies. The ultrasonographic diagnosis of small-intestinal obstruction was based on detection of an obstructive lesion, sonographic signs of plication or segmental, small-intestinal dilatation. The ultrasonographic presence or absence of moderate-to-severe intestinal diameter enlargement (due to lumen dilatation) of the jejunum (>1.5 cm) was a useful discriminatory finding and, when present, should prompt a thorough search for a cause of small-intestinal obstruction. In conclusion, both abdominal radiography and abdominal ultrasonography are accurate for diagnosing small-intestinal obstruction in vomiting dogs and either may be used depending on availability and examiner choice. Abdominal ultrasonography had greater accuracy, fewer equivocal results and provided greater diagnostic confidence compared with radiography. © 2010 Veterinary Radiology & Ultrasound.

  7. A Comparison of Panoramic, Periapical and Bite Wing Radiographies in Evaluation of Alveolar Bone Loss in Periodiontitis

    Directory of Open Access Journals (Sweden)

    A Haerian Ardakani

    2007-07-01

    Full Text Available Introduction: The height of the alveolar bone, is normally maintained by equilibrium between bone formation and bone resorption, but in periodontal disease more destruction or lack of bone formation will reduce the alveolar bone height. However the radiography is important in diagnosis, treatment plan and detection of quality and quantity of the alveolar bone; although the type of radiography is more important. The purpose of this study is the comparison between panaromic, P.A (Parallel, Bite Wing radiographs in diagnosis of periodontitis. Methods: This study was descriptive cross-Sectional study Periapical (PA, Bitewing (B.W & Panoramic radiographic images in 32 pationent 13 male and 19 female with moderate to advanced periodontitis (mean age 38 year were taken before surgical treatment. Actual hight of defect were measured by a William's probe during surgery, the distance between cemento enamel junction (CEJ and alveolar crest were measured on radiographs using a digital vernie scale as will as. Actual measurements were compared with values taken from panoramic PA, B.W radiographs. For Data analysis Paired t test was used. Results: A total of 314 linear distances from the panoramic PA , B.W, and CEJ/BL were measured. The mean difference between panoramic and actual Measurements (0.115 and 0.28 P=(0.24-0.07, were not satistically significant (P> 0.05. The mean difference between P.A and actual measurements (0.279-0.498 P=(0.0001-0.004 showed a satistically significant difference (P< 0.05. The mean deference between BW and actual Measurements (0.576-0.613 P=(0.24-0.07 were satistically significant (P<0.05. Conclusion: Although, all forms of radiographic images showed agreement in detection of periodontal bone loss, the accuracy of panoramic radiographs was more than PA & BW radiographs'. Specially when the magnification was adjusted in panoramic radiography.

  8. Sonographic appearances of common gut pathology in paediatric patients: comparison with plain abdominal radiography

    International Nuclear Information System (INIS)

    Piotto, Lino; Gent, Roger

    2004-01-01

    Even with the advent of more specialised imaging modalities such as fluoroscopic contrast examinations, CT and MRI, the plain abdominal radiograph remains the initial imaging modality in investigating the signs and symptoms of suspected gut pathology. However, ultrasound is playing an increasing part in the detection of gut pathology in paediatric patients. At our hospital, when plain abdominal radiography does not provide a diagnosis, ultrasound is commonly requested to rule out conditions that require urgent attention, such as intussusception, appendicitis and midgut malrotation and volvulus. After these conditions have been excluded however, the ultrasound examination can frequently lead to the diagnosis of several other conditions, including gastroenteritis, Crohn's disease, mesenteric lymphadenopathy and less commonly, duplication cysts, bezoas, and haemolytic uraemic syndrome. Although plain radiography of the abdomen may be suggestive of gut pathology, the additional information provided by sonography often provides a specific diagnosis, leading to better patient care. This paper is a presentation of ten case studies demonstrating the use of ultrasound to augment plain X-ray findings, in order to obtain a final diagnosis. Copyright (2004) Australian Institute of Radiography

  9. Comparison of ultrasound, digital, and conventional radiography in differentiating periapical lesions: An in vivo study

    Directory of Open Access Journals (Sweden)

    Purnachandrarao Naik Nunsavathu

    2015-01-01

    Full Text Available Aims and Objectives: To evaluate in vivo the efficacy of ultrasound, digital and conventional radiography in identifying periapical lesions. To compare the results of the above imaging modalities with histopathology, which is considered to be the gold standard for diagnosis. Materials and Methods: Thirty patients aged between 15 and 45 years with periapical lesions associated with maxillary or mandibular anterior teeth indicated for endodontic surgery or extraction were selected for the study. Pre-operatively, conventional, digital periapical radiography and ultrasonography were done and interpreted. Endodontic surgery or extraction was performed including curettage of apical tissue to enable histopathological investigation, which provided the gold standard diagnosis. All measurements and findings were compared and statistically analyzed. Results: In conventional and digital radiography, the periapical lesions were readily identified but observers were unable to differentiate granuloma from cyst using these modalities only. But ultrasonography was able to give the true nature of the periapical pathology. All the cases diagnosed by ultrasound were confirmed with histopathology, and maximal number of cases diagnosed by ultrasound correlated with the histopathological diagnosis. Conclusion: The present study confirms that ultrasound is a promising and reliable imaging technique for differentiating periapical lesions i.e., periapical cysts and granulomas. Based on the echo texture of their contents and the presence of vascularity using color Doppler, periapical cyst and granulomas can be readily identified. The present study is further applicable for the evaluation of periapical lesions of the posterior teeth and evaluation of other jaw lesions.

  10. The evolution of solid density within a thermal explosion II. Dynamic proton radiography of cracking and solid consumption by burning

    International Nuclear Information System (INIS)

    Smilowitz, L.; Henson, B. F.; Romero, J. J.; Asay, B. W.; Saunders, A.; Merrill, F. E.; Morris, C. L.; Kwiatkowski, K.; Grim, G.; Mariam, F.; Schwartz, C. L.; Hogan, G.; Nedrow, P.; Murray, M. M.; Thompson, T. N.; Espinoza, C.; Lewis, D.; Bainbridge, J.; McNeil, W.; Rightley, P.

    2012-01-01

    We report proton transmission images obtained subsequent to the laser assisted thermal ignition of a sample of PBX 9501 (a plastic bonded formulation of the explosive nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)). We describe the laser assisted thermal ignition technique as a means to synchronize a non-linear thermal ignition event while preserving the subsequent post-ignition behavior. We have obtained dynamic proton transmission images at two spatial magnifications and viewed both the radial and transverse axis of a solid cylindrical sample encased in aluminum. Images have been obtained with 3 to 15 μs temporal resolution and approximately 100 μm spatial resolution at the higher magnification. We observe case expansion from very early in the experiment, until case fragmentation. We observe spatially anisotropic features in the transmission which we attribute to cracking in the solid explosive, in agreement with previous measurements conducted on two dimensional samples with optical viewing. Digital analysis of the images also reveals spatially isotropic features which we attribute to the evolution of the loss of density by burning subsequent to thermal ignition.

  11. Evaluating the ONEBFP transport code for possible use in the proton radiography program. Final report, Task 47

    International Nuclear Information System (INIS)

    Marr, D.R.; Prael, R.E.; Adams, K.J.

    1996-10-01

    This is notification of the completion of Task 47 and a summary of the fulfillment of the requirements thereof. Deliverables for Task 47 include the data test files and a final report. The test files have been delivered to the customer and the attached paper satisfies the requirements for a final report. Detail on the completion of each of the subtasks described in the Statement of Work follow. The author repeats the complete list of subtasks for Task 47: (1) The software engineer will modify the ONEBFP code to generate a logarithmic distribution of discrete angles and an associated set of quadrature weights; (2) The software engineer will work with Group XTM personnel to obtain the required cross-section data for protons/nuclear cascade particles; and (3) The software engineer will perform 5 test calculations using the modified ONEBFP code to assess its accuracy and efficiency for proton transport problems. The test calculations will be documented in a brief report. Appendix C of the paper describes the quadrature set capability installed in the ONEBFP code pertinent to the fulfillment of subtask 1. A portion of the body of the paper describes the source and modeling and Appendix A describes the extraction of the cross section data used in this study, fulfilling subtask 2. The bulk of the attached report describes the test problems, states the modeling used for each problem, shows the results in both graphical and tabular form, and discusses the implications of the results. This fulfills the requirements of subtask 3

  12. The evolution of solid density within a thermal explosion II. Dynamic proton radiography of cracking and solid consumption by burning

    Energy Technology Data Exchange (ETDEWEB)

    Smilowitz, L.; Henson, B. F.; Romero, J. J.; Asay, B. W.; Saunders, A.; Merrill, F. E.; Morris, C. L.; Kwiatkowski, K.; Grim, G.; Mariam, F.; Schwartz, C. L.; Hogan, G.; Nedrow, P.; Murray, M. M.; Thompson, T. N.; Espinoza, C.; Lewis, D.; Bainbridge, J.; McNeil, W.; Rightley, P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); and others

    2012-05-15

    We report proton transmission images obtained subsequent to the laser assisted thermal ignition of a sample of PBX 9501 (a plastic bonded formulation of the explosive nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)). We describe the laser assisted thermal ignition technique as a means to synchronize a non-linear thermal ignition event while preserving the subsequent post-ignition behavior. We have obtained dynamic proton transmission images at two spatial magnifications and viewed both the radial and transverse axis of a solid cylindrical sample encased in aluminum. Images have been obtained with 3 to 15 {mu}s temporal resolution and approximately 100 {mu}m spatial resolution at the higher magnification. We observe case expansion from very early in the experiment, until case fragmentation. We observe spatially anisotropic features in the transmission which we attribute to cracking in the solid explosive, in agreement with previous measurements conducted on two dimensional samples with optical viewing. Digital analysis of the images also reveals spatially isotropic features which we attribute to the evolution of the loss of density by burning subsequent to thermal ignition.

  13. Comparison of the perceived image quality between two digital imaging systems for neonatal bedside radiography – A case study

    International Nuclear Information System (INIS)

    Zyl, S.A. van; Kekana, R.M.

    2015-01-01

    Background: Chest X-rays are performed daily in the neonatal intensive care and high care units. The skill of the radiographer is critical for obtaining the best image quality and limiting the patient's radiation exposure. The literature states that indirect flat panel detectors produce images of superior quality in comparison to computed radiography systems. At Steve Biko Academic Hospital a decision was made to revert from the direct digital radiography (DR) system to the computed radiography (CR) system, due to poor image quality experienced. Method: The case study objective was to conduct a comparative analysis describing key technical factors contributing to image quality. The analysis entailed retrospectively comparing the images obtained during 2010 and 2011. An image analysis form was utilised in evaluating the technical aspects of the image. A total of 160 images were viewed by 16 participants sampled from the radiography, radiology and paediatric departments. The participants were asked to re-evaluate two of their allotted images after five days to determine their reliability. Results: Findings were that the DR system provides significantly better image quality than the CR system (p < 0.05) for all the technical factors evaluated. However technical improvements are recommended. A wide variance in intra-observer reliability was also found. Conclusion: This case study demonstrated that DR images were considered to be superior to CR images. Recommendations include: a standardised technique for imaging the neonates; optimisation of the imaging software for the digital detectors, improved feedback systems in terms of exposure index values, and the training of radiographers and referring physicians in technical image analysis. - Highlights: • DR system provides better image quality than the CR system for all technical factors evaluated. • The average values obtained from the VAS showed that the DR system still needs to be optimised. • There is need

  14. Neutron radiography

    International Nuclear Information System (INIS)

    Hrdlicka, Z.

    1977-01-01

    Neutron radiography is a radiographic method using a neutron beam of a defined geometry. The neutron source usually consists of a research reactor, a specialized neutron radiography reactor or the 252 Cf radioisotope source. There are two types of the neutron radiography display system, viz., a system producing neutron radiography images by a photographic process or a system allowing a visual display, eg., using a television monitor. The method can be used wherever X-ray radiography is used except applications in the radiography of humans. The neutron radiography unit at UJV uses the WWR-S reactor as the neutron source and both types of the above mentioned display system. (J.P.)

  15. Effective radiation dose from semicoronal CT of the sacroiliac joints in comparison with axial CT and conventional radiography

    Energy Technology Data Exchange (ETDEWEB)

    Jurik, Anne Grethe; Boecker Puhakka, Katriina [Department of Radiology R, Aarhus University Hospital, Aarhus Kommunehospital, Noerrebrogade 44, 8000 Aarhus C (Denmark); Hansen, Jolanta [Department of Medical Physics, Aarhus University Hospital, Aarhus Kommunehospital, Noerrebrogade 44, 8000 Aarhus C (Denmark)

    2002-11-01

    The aim of this study was to evaluate the radiation dose given by semicoronal CT of the sacroiliac joints (SIJs) in comparison with axial CT and conventional radiography. The total effective radiation doses given by serial contiguous semicoronal and axial CT, using 5-mm slices, 120 kV and 330 mAs, were determined by measurement of organ doses using an anthropomorphic Rando Alderson phantom paced with thermoluminescence dosimeters. The doses given by conventional antero-posterior (AP) and oblique projections of the SIJs were determined similarly. In a female the total effective dose by semicoronal CT was found to be more than six times lower than by axial CT and 2.5 times lower than the dose use to obtain a conventional AP radiograph, the values being 102, 678, and 255 {mu}Sv, respectively. The effective dose by semicoronal CT was only a little higher than the dose given to obtain two oblique radiographs. In a male with lead protection of the gonads the dose by semicoronal CT was four times lower than by axial CT, but higher than by conventional radiography. In conclusion, the effective dose by semicoronal CT of the SIJs is lower than by axial CT, and in females a semicoronal CT implies a lower effective radiation dose that used to obtain an AP radiograph. (orig.)

  16. Preliminary Comparison of the Response of LHC Tertiary Collimators to Proton and Ion Beam Impacts

    CERN Document Server

    Cauchi, M; Bertarelli, A; Carra, F; Cerutti, F; Lari, L; Mollicone, P; Sammut, N

    2013-01-01

    The CERN Large Hadron Collider is designed to bring into collision protons as well as heavy ions. Accidents involving impacts on collimators can happen for both species. The interaction of lead ions with matter differs to that of protons, thus making this scenario a new interesting case to study as it can result in different damage aspects on the collimator. This paper will present a preliminary comparison of the response of collimators to proton and ion beam impacts.

  17. Proton Radiography of Spontaneous Fields, Plasma Flows and Dynamics in X-Ray Driven Inertial-Confinement Fusion Implosions

    Science.gov (United States)

    Li, C. K.; Seguin, F. H.; Frenje, J. A.; Rosenberg, M.; Zylstra, A. B.; Rinderknecht, H. G.; Petrasso, R. D.; Amendt, P. A.; Landen, O. L.; Town, R. P. J.; Betti, R.; Knauer, J. P.; Meyerhofer, D. D.; Back, C. A.; Kilkenny, J. D.; Nikroo, A.

    2010-11-01

    Backlighting of x-ray-driven implosions in empty hohlraums with mono-energetic protons on the OMEGA laser facility has allowed a number of important phenomena to be observed. Several critical parameters were determined, including plasma flow, three types of spontaneous electric fields and megaGauss magnetic fields. These results provide insight into important issues in indirect-drive ICF. Even though the cavity is effectively a Faraday cage, the strong, local fields inside the hohlraum can affect laser-plasma instabilities, electron distributions and implosion symmetry. They are of fundamental scientific importance for a range of new experiments at the frontiers of high-energy-density physics. Future experiments designed to characterize the field formation and evolution in low-Z gas fill hohlraums will be discussed.

  18. Usefulness of ultrasonography in follow-up evaluation after Ilizarov procedure : comparison with plain radiography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Hoon; Jee, Sung Woo; Lee, Ho Won; Lee, Sung Moon; Kim, Jung Sik; Kim, Hong; Song, Kwang Soon; Woo, Sung Ku [Keimyung University, Taegu (Korea, Republic of). School of Medicine; Cho, Kil Ho [Yeungnam Univ., Taegu (Korea, Republic of). School of Medicine

    1998-06-01

    The purpose of this study is to compare the usefulness of ultrasonography in follow up evaluation after the Ilizarov procedure with that of plain radiography. We analyzed ultrasound findings in twelve patients who had undergone the Ilizarov procedure, and retrospectively compared the results with the findings of plain radiography. The procedure was performed due to post-traumatic limb deformity or non-union (nine of twelve patients), congenital pseudoarthrosis (one case), sequelae of poliomyelitis (one case), and short stature (one case). The patients` mean age was 29 years; eleven of twelve were male. Ten of twelve procedures were performed on the tibia and two on the femur. After 7-10 days, distraction was initiated at a rate of 0.25 mm four times a day. Ultrasonography was performed with a 5-10 MHz linear or convex transducer; new bone formation was defined as dotted or linear echogenic foci within a hypoechoic distraction gap. Initial ultrasonographic examination was performed 2-4 weeks after distraction, and the results were compared with those of plain radiography. Color doppler imaging was performed in three cases. After the Ilizarov bone lengthening procedure, ultrasound appears to be useful for follow-up examination. New bone formation, as well as complications, can be detected earlier; it can indicate whether ultrasound-guided interventional procedure is required, and if combined with color doppler study, is able to detect the periosteal blood supply. Further evaluation of the clinical significance of preserved periosteal blood supply seems however, to be needed. (author). 18 refs., 4 figs.

  19. Acute Knee Trauma: Analysis of Multidetector Computed Tomography Findings and Comparison with Conventional Radiography

    International Nuclear Information System (INIS)

    Mustonen, A.O.T.; Kiuru, M.J.

    2005-01-01

    Purpose: To evaluate the multidetector computed tomography (MDCT) findings of acute knee trauma and to compare radiography with MDCT in patients referred ta level 1 trauma center. Material and Methods: During a 5-year period, a total of 415 MDCT examinations were performed on 409 patients with acute knee trauma to reveal complex fracture anatomy or rule out a fracture. MDCT and primary radiographs were re-evaluated with respect to fracture location and trauma mechanism. Tibial plateau fractures were further analyzed depending on anatomical location: anterior-medial, anterior-lateral, posterior-lateral, and posterior-medial regions. Maximal depression of the tibial articular surface was measured. Findings on the primary knee radiographs were compared with MDCT findings. Results: Of the 409 patients, 356 (87%) had a knee fracture. A total of 451 fractures were found in all anatomic regions: distal femur ( n = 49), proximal tibia ( n 307), patella ( n = 23), and proximal fibula ( n = 72). Primary radiographs were available in 316 (76%) cases. Of these, 225 (71%) had MDCT in order to reveal the fracture anatomy better, and 91 (29%) had a subsequent MDCT after negative plain radiographs. Overall sensitivity of radiography was 83%, while negative predictive value was 49%. On radiography, tibial plateau articular depression was underestimated in all regions except when the fracture consisted of the whole half of the anterior or posterior plateau. The three main injury mechanisms were traffic accident, a simple fall, and sport. In 49 cases (15%), primary radiographs were suboptimal due to positioning. Conclusion: In severely injured patients, diagnostically sufficient radiographs are difficult to obtain, and therefore a negative radiograph is not reliable in ruling out a fracture. In these patients, MDCT is a fast and accurate examination and is also recommended in patients with tibial plateau fractures or complex knee injuries in order to evaluate the fracture adequately

  20. Usefulness of ultrasonography in follow-up evaluation after Ilizarov procedure : comparison with plain radiography

    International Nuclear Information System (INIS)

    Lee, Jong Hoon; Jee, Sung Woo; Lee, Ho Won; Lee, Sung Moon; Kim, Jung Sik; Kim, Hong; Song, Kwang Soon; Woo, Sung Ku; Cho, Kil Ho

    1998-01-01

    The purpose of this study is to compare the usefulness of ultrasonography in follow up evaluation after the Ilizarov procedure with that of plain radiography. We analyzed ultrasound findings in twelve patients who had undergone the Ilizarov procedure, and retrospectively compared the results with the findings of plain radiography. The procedure was performed due to post-traumatic limb deformity or non-union (nine of twelve patients), congenital pseudoarthrosis (one case), sequelae of poliomyelitis (one case), and short stature (one case). The patients' mean age was 29 years; eleven of twelve were male. Ten of twelve procedures were performed on the tibia and two on the femur. After 7-10 days, distraction was initiated at a rate of 0.25 mm four times a day. Ultrasonography was performed with a 5-10 MHz linear or convex transducer; new bone formation was defined as dotted or linear echogenic foci within a hypoechoic distraction gap. Initial ultrasonographic examination was performed 2-4 weeks after distraction, and the results were compared with those of plain radiography. Color doppler imaging was performed in three cases. After the Ilizarov bone lengthening procedure, ultrasound appears to be useful for follow-up examination. New bone formation, as well as complications, can be detected earlier; it can indicate whether ultrasound-guided interventional procedure is required, and if combined with color doppler study, is able to detect the periosteal blood supply. Further evaluation of the clinical significance of preserved periosteal blood supply seems however, to be needed. (author). 18 refs., 4 figs

  1. Comparison of radiography and ultrasonography in the evaluation of renal lesions in the dog

    International Nuclear Information System (INIS)

    Konde, L.J.; Park, R.D.; Wrigley, R.H.; Lebel, J.L.

    1986-01-01

    Survey abdominal radiographs, excretory urograms, and nephrosonograms were obtained from 14 dogs with renal lesions. Renal enlargement was suspected on survey radiographs and confirmed by excretory urography in 13 dogs. Radiographic differentiation between a solid and cystic renal lesion was not possible in 9 dogs. Ultrasonography determined the presence of solid masses in 12 dogs, established the presence of a renal cyst in the opposite kidney in 1 dog, and revealed hydronephrosis in 2 dogs. Ultrasonography appeared to be more sensitive than radiography in differentiating the internal characteristics of renal lesions

  2. Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets

    Energy Technology Data Exchange (ETDEWEB)

    Morris, C. L.; Bourke, M.; Byler, D. D.; Chen, C. F.; Hogan, G.; Hunter, J. F.; Kwiatkowski, K.; Mariam, F. G.; McClellan, K. J.; Merrill, F.; Morley, D. J.; Saunders, A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2013-02-15

    We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. We also show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods have been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 {mu}m has been demonstrate, 20 {mu}m seems feasible with minor changes) for tomography on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 {mu}m resolution but further development of sources, collimation, and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.

  3. Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets

    International Nuclear Information System (INIS)

    Morris, C. L.; Bourke, M.; Byler, D. D.; Chen, C. F.; Hogan, G.; Hunter, J. F.; Kwiatkowski, K.; Mariam, F. G.; McClellan, K. J.; Merrill, F.; Morley, D. J.; Saunders, A.

    2013-01-01

    We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. We also show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods have been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 μm has been demonstrate, 20 μm seems feasible with minor changes) for tomography on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 μm resolution but further development of sources, collimation, and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.

  4. Experimental Comparison of 2-3MV X-Ray Sources for Flash Radiography

    International Nuclear Information System (INIS)

    MENGE, PETER RICHARD; JOHNSON, DAVID LEE; MAENCHEN, JOHN E.; OLSON, CRAIG L.; ROVANG, DEAN C.; DROEMER, D.; HUNT, E.; OLIVER, BRYAN VELTEN; ROSE, DAVID VINCENT; WELCH, DALE ROBERT

    2002-01-01

    High-brightness flash x-ray sources are needed for penetrating dynamic radiography for a variety of applications. Various bremsstrahlung source experiments have been conducted on the TriMeV accelerator (3MV, 60 Ω 20 ns) to determine the best diode and focusing configuration in the 2-3 MV range. Three classes of candidate diodes were examined: gas cell focusing, magnetically immersed, and rod pinch. The best result for the gas cell diode was 6 rad at 1 meter from the source with a 5 mm diameter x-ray spot. Using a 0.5 mm diameter cathode immersed in a 17 T solenoidal magnetic field, the best shot produced 4.1 rad with a 2.9 mm spot. The rod pinch diode demonstrated very reproducible radiographic spots between 0.75 and 0.8 mm in diameter, producing 1.2 rad. This represents a factor of eight improvement in the TriMeV flash radiographic capability above the original gas cell diode to a figure of merit (dose/spot diameter) > 1.8 rad/mm. These results clearly show the rod pinch diode to be the choice x-ray source for flash radiography at 2-3 M V

  5. Impact of sonography in gouty arthritis: Comparison with conventional radiography, clinical examination, and laboratory findings

    International Nuclear Information System (INIS)

    Schueller-Weidekamm, Claudia; Schueller, Gerd; Aringer, Martin; Weber, Michael; Kainberger, Franz

    2007-01-01

    Objective: To explore the typical sonographic features of gray-scale and Power Doppler of acute and chronic gouty arthritis in conjunction with radiographic, clinical, and laboratory findings. Materials and methods: All hand, finger, and toe joints of 19 patients with acute and chronic gout were examined with gray-scale and Power Doppler sonography. The number and size of bone changes detected with sonography was compared to radiographic findings. Vascularization of the synovial tissue was scored on Power Doppler (grades 0-3), and was compared with clinical appearance, including swelling, tenderness, and redness (grades 0-3). Results: In acute gout, mild to moderate echogenic periarticular nodules with sonotransmission and hypervascularization of the edematous surrounding soft tissue were found. In chronic gout, tophaceous nodules completely blocked transmission of US wave, leading to strong reflexion and dorsal shadowing in a minority of cases. No significant difference in the detection of large bone changes (>2 mm) was found between sonography and radiography. However, gray-scale sonography was significantly more sensitive in the detection of small bone changes (p < 0.001). Power Doppler scores were statistically significantly higher than clinical examination scores (p < 0.001). Discussion: Sonography is superior to radiographs in evaluating small bone changes. The inflammatory process in joints can be better detected with Power Doppler sonography than with clinical examination. Typical sonographic appearance of acute and in particular of chronic gout might provide clues on gouty arthritis that adds to the information available from conventional radiography, clinical, and laboratory findings

  6. Impact of sonography in gouty arthritis: Comparison with conventional radiography, clinical examination, and laboratory findings

    Energy Technology Data Exchange (ETDEWEB)

    Schueller-Weidekamm, Claudia [Department of Diagnostic Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)]. E-mail: claudia.schueller-weidekamm@meduniwien.ac.at; Schueller, Gerd [Department of Diagnostic Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Aringer, Martin [Department of Rheumatology, Internal Medicine III, Medical University of Vienna (Austria); Weber, Michael [Department of Diagnostic Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Kainberger, Franz [Department of Diagnostic Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)

    2007-06-15

    Objective: To explore the typical sonographic features of gray-scale and Power Doppler of acute and chronic gouty arthritis in conjunction with radiographic, clinical, and laboratory findings. Materials and methods: All hand, finger, and toe joints of 19 patients with acute and chronic gout were examined with gray-scale and Power Doppler sonography. The number and size of bone changes detected with sonography was compared to radiographic findings. Vascularization of the synovial tissue was scored on Power Doppler (grades 0-3), and was compared with clinical appearance, including swelling, tenderness, and redness (grades 0-3). Results: In acute gout, mild to moderate echogenic periarticular nodules with sonotransmission and hypervascularization of the edematous surrounding soft tissue were found. In chronic gout, tophaceous nodules completely blocked transmission of US wave, leading to strong reflexion and dorsal shadowing in a minority of cases. No significant difference in the detection of large bone changes (>2 mm) was found between sonography and radiography. However, gray-scale sonography was significantly more sensitive in the detection of small bone changes (p < 0.001). Power Doppler scores were statistically significantly higher than clinical examination scores (p < 0.001). Discussion: Sonography is superior to radiographs in evaluating small bone changes. The inflammatory process in joints can be better detected with Power Doppler sonography than with clinical examination. Typical sonographic appearance of acute and in particular of chronic gout might provide clues on gouty arthritis that adds to the information available from conventional radiography, clinical, and laboratory findings.

  7. Comparison of sputum acid-fast culture and chest radiography in pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Lim, G.M.

    1991-01-01

    While it is still a common practice of some clinicians to rely on chest radiography examination alone for the diagnosis of pulmonary tuberculosis, others still claim that absolute diagnosis of tuberculosis can firmly be established by bacteriological examination from secretions or tissues of the infected host. This study will evaluate the relationship between radiographic findings (CXR) and the likelihood of finding tubercle bacilli on sputum acid-fast bacilli (AFB) culture in pulmonary tuberculosis at Lung Center of the Philippines. Of 41 individuals who submitted their sputum for AFB culture, tubercle bacilli in the sputum was shown in 25 (60%) of cases and no growth of tubercle bacilli in 16 (40%) of cases. Chest radiography reading revealed tuberculosis in 100% of cases, of which when classified further, 22 (54%) has fibrohazed or hazy infiltrates on their CXR, 7 (17%) has cavitations or interpreted as moderate or far advanced TB, 12 (29%) has fibroid, nodular infiltrates or densities. In patients radiologically diagnosed as PTB minimal, sputum culture revealed tubercle bacilli in 15 (57%) among moderate, far advanced tuberculosis, and 6 (50%) among those with inactive or old tuberculosis. Therefore, the probability of detecting tubercle bacilli in pulmonary tuberculosis is not greatly influenced by radiographic findings. (auth.). 11 refs.; 2 figs.; 2 tabs

  8. Quality comparison between DEF-10 digital image from simulation technique and Computed Tomography (CR) technique in industrial radiography

    International Nuclear Information System (INIS)

    Siti Nur Syatirah Ismail

    2012-01-01

    The study was conducted to make comparison of digital image quality of DEF-10 from the techniques of simulation and computed radiography (CR). The sample used is steel DEF-10 with thickness of 15.28 mm. In this study, the sample is exposed to radiation from X-ray machine (ISOVOLT Titan E) with certain parameters. The parameters used in this study such as current, volt, exposure time and distance are specified. The current and distance of 3 mA and 700 mm respectively are specified while the applied voltage varies at 140, 160, 180 and 200 kV. The exposure time is reduced at a rate of 0, 20, 40, 60 and 80 % for each sample exposure. Digital image of simulation produced from aRTist software whereas digital image of computed radiography produced from imaging plate. Therefore, both images were compared qualitatively (sensitivity) and quantitatively (Signal to-Noise Ratio; SNR, Basic Spatial Resolution; SRb and LOP size) using Isee software. Radiographic sensitivity is indicated by Image Quality Indicator (IQI) which is the ability of the CR system and aRTist software to identify IQI of wire type when the time exposure is reduced up to 80% according to exposure chart ( D7; ISOVOLT Titan E). The image of the thinnest wire diameter achieved by radiograph from simulation and CR are the wire numbered 7 rather than the wire numbered 8 required by the standard. In quantitative comparison, this study shows that the SNR values decreases with reducing exposure time. SRb values increases for simulation and decreases for CR when the exposure time decreases and the good image quality can be achieved at 80% reduced exposure time. The high SNR and SRb values produced good image quality in CR and simulation techniques respectively. (author)

  9. Comparison of dynamical aspects of nonadiabatic electron, proton, and proton-coupled electron transfer reactions

    International Nuclear Information System (INIS)

    Hatcher, Elizabeth; Soudackov, Alexander; Hammes-Schiffer, Sharon

    2005-01-01

    The dynamical aspects of a model proton-coupled electron transfer (PCET) reaction in solution are analyzed with molecular dynamics simulations. The rate for nonadiabatic PCET is expressed in terms of a time-dependent probability flux correlation function. The impact of the proton donor-acceptor and solvent dynamics on the probability flux is examined. The dynamical behavior of the probability flux correlation function is dominated by a solvent damping term that depends on the energy gap correlation function. The proton donor-acceptor motion does not impact the dynamical behavior of the probability flux correlation function but does influence the magnitude of the rate. The approximations previously invoked for the calculation of PCET rates are tested. The effects of solvent damping on the proton donor-acceptor vibrational motion are found to be negligible, and the short-time solvent approximation, in which only equilibrium fluctuations of the solvent are considered, is determined to be valid for these types of reactions. The analysis of PCET reactions is compared to previous analyses of single electron and proton transfer reactions. The dynamical behavior is qualitatively similar for all three types of reactions, but the time scale of the decay of the probability flux correlation function is significantly longer for single proton transfer than for PCET and single electron transfer due to a smaller solvent reorganization energy for proton transfer

  10. Comparison of pion- and proton-production of charmonium

    International Nuclear Information System (INIS)

    Graff, T.L.

    1984-01-01

    Charomium chi states produced in π - -beryllium interactions at 190 GeV/c and in proton-beryllium interactions at 200 GeV/c and 250 GeV/c have been observed via their decay into J/Psi + γ. This experiment was carried out with the Chicago Cyclotron Magnet Spectrometer at Fermilab. The fraction of J/Psi's resulting from chi decay is measured to be 0.33 +- 0.07 for incident pions and 0.47 +- 0.21 for incident protons. The chi(3510) and chi(3555) are produced in roughly equal numbers for pions, but the chi(3555) dominates for protons. Simple gluon fusion accounts for chi production by protons. This is reasonable considering the lack of valence antiquarks in the proton-beryllium system. Other mechanisms are needed to explain chi production by pions

  11. Digital radiography

    International Nuclear Information System (INIS)

    Zani, M.L.

    2002-01-01

    X-ray radiography is a very common technique used to check the homogeneity of a material or the inside of a mechanical part. Generally the radiation that goes through the material to check, produced an image on a sensitized film. This method requires time because the film needs to be developed, digital radiography has no longer this inconvenient. In digital radiography the film is replaced by digital data and can be processed as any computer file. This new technique is promising but its main inconvenient is that today its resolution is not so good as that of film radiography. (A.C.)

  12. Bone marrow scintigraphy with antigranulocyte antibody in multiple myeloma: comparison with simple radiography and bone scintigraphy

    International Nuclear Information System (INIS)

    Kim, Dong Hwan; Lee, Jae Tae; Baek, Jin Ho

    1998-01-01

    Simple X-ray study and bone scan have limitations for early diagnosis of bone or bone marrow lesions in multiple myeloma. The purpose of this study was to evaluate the diagnostic usefulness of bone marrow immunoscintigraphy using anti-granulocyte monoclonal antibody for the evaluation of bone involvement in multiple myeloma. In 22 patients (Male: 15, Female: 7) with multiple myeloma, we performed whole-body immunoscintigraphy using 99m Tc-labelled antigranulocyte antibody (BW 250/183, Scintimum Granulozyt R CIS, France) and compared the findings with those of simple bone radiography and 99m Tc-MDP bone scan. Abnormal findings in bone marrow scintigraphy were considered to be present in case of expansion of peripheral bone marrow or focal photon defect in axial bones. Marrow expansion was noted in 15 of 22 patients (68%). Focal photon defects were found in 18 patients (82%). While one (33%) of 3 patients with Stage II disease showed focal defects in bone marrow scan, abnormal focal defects were observed in 17 of 19 (90%) patients with Stage III. Among 124 focal abnormal sites which were observed in bone marrow scan, bone scan or simple bone radiography, bone marrow scan detected 92 sites (74%), whereas 82 sites (66%) were observed in simple bone radiogrpahy (58 sites, 47%) or bone scan (40 sites, 32%). Fifty-one(41%) out of 124 bone lesions were detected by bone marrow scan only, and located mostly in thoracolumbar spine. Bone marrow scan using 99m Tc-labelled antigranulocyte antibody seems to be a more sensitive procedure for the detection of pathologic bone lesions than simple bone X-ray or bone scan in patients with multiple myeloma

  13. A comparison of the diagnostic utility of two image receptors for panoramic radiography.

    Science.gov (United States)

    Carmichael, F A; Hirschmann, P N; Scaife, B; Sheard, L; Mackenzie, A

    2000-01-01

    To compare the diagnostic utility of two screen-film systems for panoramic radiography, one based on green and the other on ultraviolet light. Two hundred consecutive adult patients with teeth in all four quadrants requiring panoramic radiographs were randomly allocated to one of two groups. One group was imaged with OGA L (CEA AB, Strängnäs, Sweden) film using Lanex Regular (Eastman Kodak, Rochester, NY, USA) screens (the Lanex group). The other group was imaged using Ultra-Vision (Dupont UK Limited, Hertfordshire, UK) film and screens (the Ultra-vision group). Two different panoramic machines were used, a Planmeca (Planmeca OY, Helsinki, Finland) and Cranex (Soredex Orion Corporation, Helsinki, Finland). The radiographs were evaluated by two radiographers for overall quality and any faults recorded. Two dental radiologists evaluated the crestal and apical areas of every standing tooth on a 4-point scale. The likelihood of getting a high-quality image with the different films was modelled using logistic regression, adjusting for the radiologist and the area of the tooth being examined. Inter- and intra-examiner agreement was calculated using Kappa and weighted Kappa where appropriate. The radiographers recorded no significant differences in positioning errors between the two groups of film. However, the films produced on the Cranex were less likely to be recorded as excellent. The radiologists' interexaminer agreement for the lower molars and upper incisors was only moderate at best (kappa = 0.56). No significant differences were found between the likelihood of the two types of film providing a high-quality image. Crestal areas were more likely to be scored well than apical areas. There were no differences in ease of discerning apical and crestal areas between the two screen-film systems. There was only poor to moderate agreement between the two radiologists. Ultra-Vision can be recommended as an alternative to existing rare earth systems for panoramic

  14. Free focus radiography with miniaturized dental x-ray machines: a comparison of ''midline'' and ''lateral'' techniques

    International Nuclear Information System (INIS)

    Jensen, T.W.

    1983-01-01

    The use of free focus radiography (FFR) employing miniaturized dental x-ray machines with radiation probes has never been generally accepted in dentistry despite its recognized radiographic potential. The present investigation studied ways to improve imaging and lower radiation burdens in dental free focus radiography. Relatively high air exposures ranging from 42,050 mR per film for high-resolution images to 3,214 mR per film for lower-resolution images using a current midline radiographic technique for panoramic FFR were found. In a proposed lateral FFR panoramic technique, reduced exposures ranged from 420 mR per film for high-resolution images to 14 mR per film for lower-resolution images. In each technique the lower exposure was obtained with a rare earth imaging system. A proposed modification of the current midline FFR technique using a rare earth imaging system and heavy added copper filtration was found to produce exposures in the range normally used in dentistry (207 mr), and the resultant image was high in contrast with relatively low detail. A comparison of essential characteristics of midline and lateral FFR techniques failed to identify specific advantages for the midline technique in current use. Lateral exposure modes in dental FFR should receive increased attention in the interest of good imaging and radiation control. It was noted that existing miniaturized dental x-ray machines may have been designed specifically for use of the midline FFR exposure technique, and modification of this equipment to support reliable lateral exposure modes was recommended

  15. Military radiography

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Historic military uses of radiography are discussed in this chapter: Battle of Adowa in 1986 was the first. Besides describing the early campaigns in which radiography was used, the author discusses the problems faced: a reliable source of electricity; the problems of extreme heat; moving and breakage of equipment. Numerous historical photographs are included. 9 refs

  16. SU-E-T-210: Comparison of Proton with Electron Boost in Breast Cancer Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Y; Chang, A [Procure Proton Therapy Center, Oklahoma City, OK (United States); Liu, Y [INTEGRIS Cancer Institute of Oklahoma, Oklahoma City, OK (United States)

    2015-06-15

    Purpose: Electron beams are commonly used for boost radiation following whole breast irradiation (WBI) to improve the in-breast local control. Proton beams have a finite range and a sharper distal dose falloff compared to electron beams, thus potentially sparing more heart and lung in breast treatment. The purpose of the study is to compare protons with electrons for boost breast treatment in terms of target coverage and normal tissue sparing. Methods: Six breast cancer patients were included in this study. All women received WBI to 45–50 Gy, followed by a 10–16.2 Gy boost with standard fractionation. If proton beams were used for the boost treatment, an electron plan was retrospectively generated for comparison using the same CT set and structures, and vice versa if electron beams were used for treatment. Proton plans were generated using the treatment planning system (TPS) with two to three uniform scanning proton beams. Electron plans were generated using the Pinnacle TPS with one single en face beam. Dose-volume histograms (DVH) were calculated and compared between proton and electron boost plans. Results: Proton plans show a similar boost target coverage, similar skin dose, and much better heart and lung sparing. For an example patient, V95% for PTV was 99.98% and skin (5 mm shell) received a max dose close to the prescription dose for both protons and electrons; however, V2 and V5 for the ipsilateral lung and heart were 37.5%, 17.9% and 19.9%, 4.9% respectively for electrons, but were essentially 0 for protons. Conclusions: This dosimetric comparison demonstrates that while both proton therapy and electron therapy provided similar coverage and skin dose, proton therapy could largely reduce the dose to lung and heart, thus leading to potential less side effects.

  17. Timing Comparisons for GLEs and High-energy Proton Events using GPS Proton Measurements

    Science.gov (United States)

    Bernstein, V.; Winter, L. M.; Carver, M.; Morley, S.

    2017-12-01

    The newly released LANL GPS particle sensor data offers a unique snapshot of access of relativistic particles into the geomagnetic field. Currently, 23 of the 31 operational GPS satellites host energetic particle detectors which can detect the arrival of high-energy solar protons associated with Ground Level Enhancements (GLEs). We compare the timing profiles of solar energetic proton detections from GPS satellites as well as from ground-based Neutron Monitors and GOES spacecraft at geostationary orbit in order to understand how high-energy protons from the Sun enter the geomagnetic field and investigate potential differences in arrival time of energetic protons at GPS satellites as a function of location. Previous studies could only use one or two spacecraft at a similar altitude to track the arrival of energetic particles. With GPS data, we can now test whether the particles arrive isotropically, as assumed, or whether there exist differences in the timing and energetics viewed by each of the individual satellites. Extensions of this work could lead to improvements in space weather forecasting that predict more localized risk estimates for space-based technology.

  18. Comparison of low-contrast detectability of computed radiography and screen/ film mammography systems

    International Nuclear Information System (INIS)

    Noriah Jamal; Kwan-Hoong Ng; McLean, D.; McLean, D.

    2008-01-01

    The objective of this study is to compare low-contrast detectability of computed radiography (CR) and screen/ film (SF) mammography systems. The Nijimegen contrast detail test object (CDMAM type 3.4) was imaged at 28 kV, in automatic exposure control mode separately. Six medical imaging physicists read each CDMAM phantom image. Contrast detail curves were plotted to compare low-contrast detectability of CR (soft copy and hard copy) and SF mammography systems. Effect of varying exposure parameters, namely kV, object position inside the breast phantom, and entrance surface exposure (ESE) on the contrast detail curve were also investigated using soft copy CR. The significance of the difference in contrast between CR and SF, and for each exposure parameter, was tested using non-parametric Kruskal-Wallis test. The low-contrast detectability of the CR (soft copy and hard copy) system was found to be not significantly different to that of the SF system (p> 0.05, Kruskal-Wallis test).For CR soft copy, no significant relationship (p>0.05, Kruskal-Wallis test) was seen for variation of kV, object position inside the breast phantom and ESE. This indicates that CR is comparable with SF for useful detection and visualization of low-contrast objects such as small low-contrast areas corresponding to breast pathology. (Author)

  19. Storage phosphor radiography of wrist fractures: a subjective comparison of image quality at varying exposure levels

    Energy Technology Data Exchange (ETDEWEB)

    Peer, Regina; Giacomuzzi, Salvatore M.; Bodner, Gerd; Jaschke, Werner; Peer, Siegfried [Innsbruck Univ. (Austria). Inst. fuer Radiologie; Lanser, Anton [Academy of Radiology Technicians, Innsbruck (Austria); Pechlaner, Sigurd [Department of Traumatology, University Hospital, Innsbruck (Austria); Kuenzel, Karl Heinz; Gaber, O. [Department of Anatomy and Histology, University Hospital, Innsbruck (Austria)

    2002-06-01

    Image quality of storage phosphor radiographs acquired at different exposure levels was compared to define the minimal radiation dose needed to achieve images which allow for reliable detection of wrist fractures. In a study on 33 fractured anatomical wrist specimens image quality of storage phosphor radiographs was assessed on a diagnostic PACS workstation by three observers. Images were acquired at exposure levels corresponding to a speed classes 100, 200, 400 and 800. Cortical bone surface, trabecular bone, soft tissues and fracture delineation were judged on a subjective basis. Image quality was rated according to a standard protocol and statistical evaluation was performed based on an analysis of variance (ANOVA). Images at a dose reduction of 37% were rated sufficient quality without loss in diagnostic accuracy. Sufficient trabecular and cortical bone presentation was still achieved at a dose reduction of 62%. The latter images, however, were considered unacceptable for fracture detection. To achieve high-quality storage phosphor radiographs, which allow for a reliable evaluation of wrist fractures, a minimum exposure dose equivalent to a speed class of 200 is needed. For general-purpose skeletal radiography, however, a dose reduction of up to 62% can be achieved. A choice of exposure settings according to the clinical situation (ALARA principle) is recommended to achieve possible dose reductions. (orig.)

  20. Comparison of the new and the used imaging plates on computed radiography

    International Nuclear Information System (INIS)

    Ding Weihong; Zhang Weimin; Wang Jiawei

    2008-01-01

    Objective: To compare image quality and radiation dose of the new imaging plate (IP) with the used IP on computed radiography (CR), and to investigate the using principle in the two kinds of IP. Methods: The dark noise, uniformity and erasure thoroughness of the new and the used IP were measured respectively. Based on threshold contrast-detail detectability (TCCD) technique, the phantom TO, 16 photography was done at 75 kV, and with the two kinds of IP respectively. Three observers scored each image sequence using double blind method, calculated the threshold detection index (H T ). The volunteers were randomly divided into three groups: the knee joint group, the chest group and the lumbar group. Each group had 50 cases and checked with the same condition as the phantom. Three radiologists using double blind method evaluated the imaging quality of knee joint, chest and lumbar. Results: The physical characteristic indexes of the new and the used IP were similar to each other. Under the same condition, the detection ability of the new IP was better than that of the used one. When the dose of exposure was raised about 20%, the detection ability of the used IP was close to that of the new one. Conclusions: The dose of exposure can be raised to keep the same imaging quality with the increase times of IP used. The detection ability of IP can decrease with the same dose as before, and the image quality decreases too. (authors)

  1. High intensification screen-film systems in thorax radiography: a clinical comparison

    International Nuclear Information System (INIS)

    Schaefer, C.B.; Sokiranski, R.; Claussen, C.D.

    1995-01-01

    Objective: The quality of chest images was evaluated for a conventional screen-film system, a new asymmetric screen-film system, and a new uv screen-film system. Materials and Methods: 138 Chest radiographs (69 p.a., 69 lateral) obtained with three different high intensification screen-film combinations were compared. Film density and film contrast were measured. Three readers graded the image quality according to 16 criteria. Results: The asymmetric film-screen combination Insight HC showed the lowest film contrast, the best exposure range, and a elevated film density in the mediastinal area. The asymmetric screen-film system was ranked by all three observers as being substantially better in image quality. Conclusion: Compared to conventional screen-film systems, the new screen-film systems can improve the image quality of chest radiographs. Therefore, the new high intensification screen-film combinations can be used as a low cost alternative to the Amber technique and digital radiography. (orig.) [de

  2. Ultrasonography X gamma radiography

    International Nuclear Information System (INIS)

    Mello Campos, A.M. de

    1989-01-01

    The accumulated experience in the last ten years of substitution to essays by gamma radiography to essay by ultrasonography, starting of the systematic comparison and tabulation of the results obtained by both essays applied in welding joints, in field, in steel pipelines of the SABESP. (V.R.B.)

  3. Technical Note: A direct ray-tracing method to compute integral depth dose in pencil beam proton radiography with a multilayer ionization chamber.

    Science.gov (United States)

    Farace, Paolo; Righetto, Roberto; Deffet, Sylvain; Meijers, Arturs; Vander Stappen, Francois

    2016-12-01

    To introduce a fast ray-tracing algorithm in pencil proton radiography (PR) with a multilayer ionization chamber (MLIC) for in vivo range error mapping. Pencil beam PR was obtained by delivering spots uniformly positioned in a square (45 × 45 mm 2 field-of-view) of 9 × 9 spots capable of crossing the phantoms (210 MeV). The exit beam was collected by a MLIC to sample the integral depth dose (IDD MLIC ). PRs of an electron-density and of a head phantom were acquired by moving the couch to obtain multiple 45 × 45 mm 2 frames. To map the corresponding range errors, the two-dimensional set of IDD MLIC was compared with (i) the integral depth dose computed by the treatment planning system (TPS) by both analytic (IDD TPS ) and Monte Carlo (IDD MC ) algorithms in a volume of water simulating the MLIC at the CT, and (ii) the integral depth dose directly computed by a simple ray-tracing algorithm (IDD direct ) through the same CT data. The exact spatial position of the spot pattern was numerically adjusted testing different in-plane positions and selecting the one that minimized the range differences between IDD direct and IDD MLIC . Range error mapping was feasible by both the TPS and the ray-tracing methods, but very sensitive to even small misalignments. In homogeneous regions, the range errors computed by the direct ray-tracing algorithm matched the results obtained by both the analytic and the Monte Carlo algorithms. In both phantoms, lateral heterogeneities were better modeled by the ray-tracing and the Monte Carlo algorithms than by the analytic TPS computation. Accordingly, when the pencil beam crossed lateral heterogeneities, the range errors mapped by the direct algorithm matched better the Monte Carlo maps than those obtained by the analytic algorithm. Finally, the simplicity of the ray-tracing algorithm allowed to implement a prototype procedure for automated spatial alignment. The ray-tracing algorithm can reliably replace the TPS method in MLIC PR for in

  4. Comparison of Monte Carlo simulations with proton experiment for a thick Au absorber

    International Nuclear Information System (INIS)

    Yevseyeva, Olga; Assis, Joaquim T. de; Diaz, Katherin S.; Hormaza, Joel M.; Lopes, Ricardo T.

    2009-01-01

    Proton therapy applications deal with relatively thick targets like the human head or the trunk. Therefore, relatively small differences in the total proton stopping power given, for example, by the different models provided by GEANT4, could lead to significant disagreement in the final proton energy spectra when integrated along lengthy proton trajectories. This work presents a comparison of proton energy spectra for 49.1 MeV protons passing through a couple of Au absorbers with different thicknesses obtained by GEANT4.8.2 simulations using ICRU49, Ziegler1985 and Ziegler2000 models. The comparison was made with the experimental data of Tschalaer, with TRIM/SRIM2008 and MCNPX2.4.0 simulations, and the Payne analytical solution for the transport equation in the Fokker-Plank approximation. It is shown that the simulations reproduce the experimental spectra with some detectable contradictions. It should be noted that all the spectra lay at the proton energies significantly above 2 MeV, i.e. in the so-called 'Bethe-Bloch region'. Therefore the observed disagreements in GEANT4 results, simulated with different models, are somewhat unexpected. Further studies for a better understanding and to obtain definitive conclusions are necessary. (author)

  5. Digital radiography

    International Nuclear Information System (INIS)

    Kusano, Shoichi

    1993-01-01

    Firstly, from an historic point of view, fundamental concepts on digital imaging were reviewed to provide a foundation for discussion of digital radiography. Secondly, this review summarized the results of ongoing research in computed radiography that replaces the conventional film-screen system with a photo-stimulable phosphor plate; and thirdly, image quality, radiation protection, and image processing techniques were discussed with emphasis on picture archiving and communication system environment as our final goal. Finally, future expansion of digital radiography was described based on the present utilization of computed tomography at the National Defense Medical College Hospital. (author) 60 refs

  6. Comparison of Digital Tomosynthesis and Chest Radiography for the Detection of Noncalcified Pulmonary and Hilar Lesions.

    Science.gov (United States)

    Galea, Angela; Adlan, Tarig; Gay, David; Roobottom, Carl; Dubbins, Paul; Riordan, Richard

    2015-09-01

    The aim of this study was to compare the sensitivity and specificity of chest digital tomosynthesis (DTS) with chest radiography (CXR) for the detection of noncalcified pulmonary nodules and hilar lesions using computed tomography (CT) as the reference standard. A total of 78 patients with suspected noncalcified pulmonary lesions on CXR were included in the study. Two radiologists, blinded to the history and CT, analyzed the CXR and the DTS images (separately), whereas a third radiologist analyzed the CXR and DTS images together. Noncalcified intrapulmonary nodules and hilar lesions were recorded for analysis. The interobserver agreement for CXR and DTS was assessed, and the time taken to report the images was recorded. A total of 202 lesions were recorded in 78 patients. There were 111 true lesions confirmed on CT in 53 patients; in 25 patients subsequent CT excluded a lesion. The overall sensitivity was 32% for CXR and 49% for DTS. This improved to 54% when the posteroanterior CXR and DTS were reviewed together (CXR-DTS). The overall specificities for CXR, DTS, and CXR-DTS were 49%, 96%, and 98%, respectively. There were 56 suspected hilar lesions with subgroup sensitivities of 76% for CXR, 65% for DTS, and 76% for CXR-DTS. The specificity for hilar lesions was 59%, 92%, and 97% for CXR, DTS, and CXR-DTS, respectively. DTS significantly improves the detectability of noncalcified nodules when compared with and when used in combination with CXR. The specificity and interobserver agreement of DTS in the diagnosis of suspected noncalcified pulmonary nodules and hilar lesions are significantly better than those of CXR and approaches those of CT.

  7. Lateralized odontoid in plain film radiography. Sign of fractures? A comparison study with MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Keller, S.; Bieck, K.; Karul, M.; Schoennagel, B.; Adam, G.; Habermann, C.; Yamamura, J. [University Hospital Hamburg Eppendorf (Germany). Dept. of Diagnostic and Interventional Radiology

    2015-09-15

    To evaluate X-ray standards for the detection of odontoid fractures. Summary of background data: Cervical spine fractures are a common finding in emergency medicine, accounting for 1 - 3 % of injuries. Involvement of the C1 / C2 complex is found in 25 % of cases, affecting the odontoid peg in 55 - 80 %. Regarding the consequences of missed fractures, radiographic techniques built the groundwork for further treatment procedures. As standardized X-ray measurements have not been established, the incidence of unrecognized cervical spine fracture is expected to be up to 20 %. The establishment of X-ray-based guidelines is also limited by the presumed low specificity and sensitivity of distance measurements caused by rotational distortion which leads to a rising popularity of CT. 79 (age 60 ± 26 yrs) patients with lateralization of the odontoid process on conventional plain film radiography (anteroposterior, lateral, and open mouth odontoid process view projection) were examined. The distance between the odontoid process and lateral mass of C1, angles of vertical odontoid line and basis of C2 were measured in the ap view. In the lateral view, dorsal alignment and atlantodental distance were assessed. MDCT examinations were used as a reference. Discriminatory power test was applied to assess significance. 8/79 (10.1 %) odontoid process fractures were found. Diagnosis was achieved on conventional radiographs in 6 patients. Neither distance and angle measurements between odontoid and C1 nor the dorsal alignment of the vertebral bodies differed significantly between healthy and affected patients. Decentralization of the odontoid process is not necessarily an indirect sign for its fracture. In patients with suspected injury of the odontoid process, an MDCT scan might be the method of choice to rule out a fracture.

  8. COMPARISON OF COMPUTED TOMOGRAPHY AND ABDOMINAL RADIOGRAPHY FOR DETECTION OF CANINE MECHANICAL INTESTINAL OBSTRUCTION.

    Science.gov (United States)

    Drost, Wm Tod; Green, Eric M; Zekas, Lisa J; Aarnes, Turi K; Su, Lillian; Habing, Gregory G

    2016-07-01

    Vomiting, often caused by mechanical intestinal obstruction, is common in dogs. Equivocal radiographic signs often necessitate repeat radiographs or additional imaging procedures. For our prospective, case-controlled, accuracy study, we hypothesized the following: (1) using computed tomography (CT), radiologists will be more sensitive and specific for detecting mechanical intestinal obstruction and recommending surgery compared to using radiographs; and (2) using measurements, radiologists will be more sensitive and specific using radiographs or CT for detecting mechanical intestinal obstruction and recommending surgery. Twenty dogs had abdominal radiographs and abdominal CT. Seventeen dogs had abdominal surgery and three dogs were not obstructed based on clinical follow-up. Confidence levels (five-point scale) of three experienced radiologists for mechanical intestinal obstruction and recommending surgery were recorded before and after making selected measurements. Eight dogs had surgically confirmed mechanical intestinal obstruction, and 12 dogs did not have obstruction. For detecting mechanical intestinal obstruction, CT was more sensitive (95.8% vs. 79.2%) and specific (80.6% vs. 69.4%) compared to radiographs, but the difference was not statistically significant. For recommending surgery, radiography was more sensitive (91.7% vs. 83.3%) and specific (83.3% vs. 72.2%) than using CT, but differences were not statistically significant. We reported objective CT measurements for predicting small mechanical intestinal obstruction. By incorporating these objective data, the diagnosis of mechanical intestinal obstruction changed in five of 120 instances (radiographs and CT). In no instance (0/120), did the objective data change the recommendation for surgery. Using CT or abdominal radiographs for the detection of canine mechanical intestinal obstruction is sensitive and specific when evaluated by experienced veterinary radiologists. © 2016 American College of

  9. Comparison of Ultrasonography and Radiography in Detection of Thoracic Bone Fractures; a Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Yousefifard, Mahmoud; Baikpour, Masoud; Ghelichkhani, Parisa; Asady, Hadi; Darafarin, Abolfazl; Amini Esfahani, Mohammad Reza; Hosseini, Mostafa; Yaseri, Mehdi; Safari, Saeed

    2016-01-01

    The potential benefit of ultrasonography for detection of thoracic bone fractures has been proven in various surveys but no comprehensive conclusion has been drawn yet; therefore, the present study aimed to conduct a thorough meta-analytic systematic review on this subject. Two reviewers independently carried out a comprehensive systematic search in Medline, EMBASE, ISI Web of Knowledge, Scopus, Cochrane Library, and ProQuest databases. Data were summarized as true positive, false positive, true negative and false negative and were analyzed via STATA 11.0 software using a mixed-effects binary regression model. Sources of heterogeneity were further assessed through subgroup analysis. Data on 1667 patients (807 subjects with and 860 cases without thoracic fractures), whose age ranged from 0 to 92 years, were extracted from 17 surveys. Pooled sensitivity and specificity of ultrasonography in detection of thoracic bone fractures were 0.97 (95% CI: 0.90-0.99; I2= 88.88, prib fractures, compared to fractures of sternum or clavicle (97% vs. 91%). Moreover, the sensitivity was found to be higher when the procedure was carried out by a radiologist in comparison to an emergency medicine specialist (96% vs. 90%). Base on the findings of the present meta-analysis, screening performance characteristic of ultrasonography in detection of thoracic bone fractures was found to be higher than radiography. However, these characteristics were more prominent in detection of rib fractures and in cases where was performed by a radiologist.

  10. Neutron radiography

    International Nuclear Information System (INIS)

    Bayon, G.

    1989-01-01

    Neutronography or neutron radiography, a non-destructive test method which is similar in its principle to conventional X-ray photography, presently occupies a marginal position among non-destructive test methods (NDT) (no source of suitable performance or cost). Neutron radiography associated with the ORPHEE reactor permits industrial testing; it can very quickly meet a cost requirement comparable to that of conventional test methods. In 1988, 2500 parts were tested on this unit [fr

  11. Industrial radiography

    International Nuclear Information System (INIS)

    1994-01-01

    This Health and Safety Executive Information Sheet on industrial radiography aims to inform directors and managers of industrial radiography companies on the safety precautions necessary to ensure that their personnel do not exceed dose guidelines for exposure to ionizing radiation. The Ionising Radiations Regulations 1985 (IRR85) require that exposure doses for radiographers are kept as low reasonably practicable. Equipment maintenance, and the employment of proper emergency procedures will help to ensure personnel safety. (UK)

  12. Comparison of the diagnostic value of ultrasonography and standing radiography for pelvic-femoral disorders in horses.

    Science.gov (United States)

    Geburek, Florian; Rötting, Anna K; Stadler, Peter M

    2009-04-01

    To assess agreement between ultrasonography (transcutaneous and transrectal) and standing radiography in horses with fractures in the pelvic region and disorders of the coxofemoral joint. Case series. Warmblood horses (n=23) and 2 ponies. Medical records (1999-2008) of equids with pelvic or coxofemoral disorders that had pelvic radiography and ultrasonography were retrieved and results of both techniques compared. Radiography and ultrasonography each identified equal numbers of fractures of the tuber coxa (n=4), ilial shaft (2), ischium (3), femoral neck (2), and osteoarthritis/osis of the coxofemoral joint (6). Fractures of the ilial wing (4) were only identified by ultrasonography not by standing radiography. Of 9 acetabular fractures, 3 were identified on radiographs only, 5 were identified with both modalities. One pubic fracture was identified using ultrasonography and radiography. One acetabular and 1 pubic fracture were only diagnosed on necropsy. We found reasonable agreement (73%; 24/33) between ultrasonography and standing radiography for diagnosis of pelvic-femoral disorders. Ultrasonography was more useful for ilial wing fractures and radiography for acetabular fractures. Ultrasonography is a rapid, safe imaging technique for detecting disorders of the pelvic region with a high diagnostic yield and is a preferred initial approach in horses with severe hindlimb lameness.

  13. A comparison of digital tomosynthesis and chest radiography in evaluating airway lesions using computed tomography as a reference

    International Nuclear Information System (INIS)

    Choo, Ji Yung; Lee, Ki Yeol; Choi, Jung Won; Yu, Ami; Kim, Je-Hyeong; Lee, Seung Heon; Kang, Eun-Young; Oh, Yu Whan

    2016-01-01

    To compare the diagnostic performance of digital tomosynthesis (DTS) and chest radiography for detecting airway abnormalities, using computed tomography (CT) as a reference. We evaluated 161 data sets from 149 patients (91 with and 70 without airway abnormalities) who had undergone radiography, DTS, and CT to detect airway problems. Radiographs and DTS were evaluated to localize and score the severity of the airway abnormalities, and to score the image quality using CT as a reference. Receiver operating characteristics (ROC), McNemar's test, weighted kappa, and the paired t-test were used for statistical analysis. The sensitivity of DTS was higher (reader 1, 93.51 %; reader 2, 94.29 %) than chest radiography (68.83 %; 71.43 %) in detecting airway lesions. The diagnostic accuracy of DTS (90.91 %; 94.70 %) was also significantly better than that of radiography (78.03 %; 82.58 %, all p < 0.05). DTS image quality was significantly better than chest radiography (1.83, 2.74; p < 0.05) in the results of both readers. The inter-observer agreement with respect to DTS findings was moderate and superior when compared to radiography findings. DTS is a more accurate and sensitive modality than radiography for detecting airway lesions that are easily obscured by soft tissue structures in the mediastinum. (orig.)

  14. A comparison of digital tomosynthesis and chest radiography in evaluating airway lesions using computed tomography as a reference.

    Science.gov (United States)

    Choo, Ji Yung; Lee, Ki Yeol; Yu, Ami; Kim, Je-Hyeong; Lee, Seung Heon; Choi, Jung Won; Kang, Eun-Young; Oh, Yu Whan

    2016-09-01

    To compare the diagnostic performance of digital tomosynthesis (DTS) and chest radiography for detecting airway abnormalities, using computed tomography (CT) as a reference. We evaluated 161 data sets from 149 patients (91 with and 70 without airway abnormalities) who had undergone radiography, DTS, and CT to detect airway problems. Radiographs and DTS were evaluated to localize and score the severity of the airway abnormalities, and to score the image quality using CT as a reference. Receiver operating characteristics (ROC), McNemar's test, weighted kappa, and the paired t-test were used for statistical analysis. The sensitivity of DTS was higher (reader 1, 93.51 %; reader 2, 94.29 %) than chest radiography (68.83 %; 71.43 %) in detecting airway lesions. The diagnostic accuracy of DTS (90.91 %; 94.70 %) was also significantly better than that of radiography (78.03 %; 82.58 %, all p chest radiography (1.83, 2.74; p < 0.05) in the results of both readers. The inter-observer agreement with respect to DTS findings was moderate and superior when compared to radiography findings. DTS is a more accurate and sensitive modality than radiography for detecting airway lesions that are easily obscured by soft tissue structures in the mediastinum. • Digital tomosynthesis offers new diagnostic options for airway lesions. • Digital tomosynthesis is more sensitive and accurate than radiography for airway lesions. • Digital tomosynthesis shows better image quality than radiography. • Assessment of lesion severity, via tomosynthesis is comparable to computed tomography.

  15. Comparison of gamma, neutron and proton irradiations of multimode fibers

    International Nuclear Information System (INIS)

    Gingerich, M.E.; Dorsey, K.L.; Askins, C.G.; Friebele, E.J.

    1987-01-01

    The effects of pure gamma, pure proton, and mixed neutron-gamma irradiation fields on a set of both pure and doped silica core multimode fibers have been investigated. Only slight differences are found in the radiation response of pure and doped silica core fibers exposed to gamma or mixed neutron-gamma fields, indicating that Co-60 sources can be used to simulate the effects of the mixed field (except in the case of a pure neutron environment). Although it is noted that neither mix field nor gamma sources adequately simulate the effects of proton irradiation of doped silica core fibers, a good correspondence is found in the case of the pure silica core waveguide. 13 references

  16. Neutron radiography by using JSW baby cyclotron

    International Nuclear Information System (INIS)

    Toda, Yojiro

    1995-01-01

    At present, JSW baby cyclotrons are mostly used for the production of the radioisotopes for medical use. The attempt to use this baby cyclotron for neutron radiography began already in 1981. The feasibility of the neutron radiography for the explosives in metallic cases which are used for H1 rockets was investigated. In 1983, it was shown that the neutron radiography by using the baby cyclotron in Muroran Works, Japan Steel Works, Ltd. was able to be carried out as a routine work. Since then, the nondestructive inspection by neutron radiography has been performed for rocket pyrotechnic articles, and contributed to heighten their reliability. Further, the radiography by using fast neutrons was developed and put to practical use for recent large H2 rockets. The JSW baby cyclotron BC 168 which has been used for neutron radiography can accelerate 16 MeV protons or 8 MeV deuterons up to 50 μA. The principle of thermal neutron radiography is the generation of fast neutrons by irradiating a Be target with the proton beam accelerated by a baby cyclotron, the moderation of the fast neutrons, the formation of the thermal neutron flux of uniform distribution with a collimator, the thermal neutron flux hitting the Gd plate in a film cassette through an object, and the exposure of an X-ray film to electrons from the Gd plate. Fast neutron radiography apparatus, and commercial neutron radiography are described. (K.I.)

  17. Charmonium production in proton-proton collisions and in collisions of lead nuclei at CERN and comparison with Brookhaven data

    International Nuclear Information System (INIS)

    Topilskaya, N. S.

    2013-01-01

    A review of experimental data on charmoniumproduction that were obtained in fixed-target experiments at the SPS synchrotron and in proton-proton collisions and in collisions of lead nuclei in beams of the Large Hadron Collider (LHC) at CERN (Switzerland) is presented. A comparison with data obtained at the Brookhaven National Laboratory (USA) from experiments at the Relativistic Heavy Ion Collider (RHIC) is performed. Measurement of the suppression of J/ψ-meson production as a possible signal of the production of quark-gluon plasmawas proposed back in 1986 by T. Matsui and H. Satz. An anomalous suppression of J/ψ-meson production was discovered by the NA50 Collaboration at SPS (CERN) in central collisions of lead nuclei at the c.m. collision energy of 158 GeV per nucleon. Data obtained at the c.m. energy of 200 GeV per nucleon in the PHENIX experiment at RHIC indicate that, depending on multiplicity, the suppression of J/ψ-meson production at this energy approximately corresponds to the suppression of J/ψ-meson production in collisions of lead nuclei at the SPS accelerator. Theoretical models that take into account the regeneration of J/ψ mesons describe better RHIC experimental data. The measurement of charmonium production in proton-proton collisions and in collisions of lead nuclei in LHC beams revealed the importance of taking into account the regeneration process. At the LHC energies, it is also necessary to take into account the contribution of B-meson decays. Future measurements of charmonium production at the LHC to a higher statistical precision and over an extended energy region would be of importance for obtaining deeper insight into the mechanism of charmonium production and for studying the properties of matter at high energy density and temperature

  18. Industrial radiography

    International Nuclear Information System (INIS)

    1992-01-01

    Industrial radiography is a non-destructive testing (NDT) method which allows components to be examined for flaws without interfering with their usefulness. It is one of a number of inspection methods which are commonly used in industry to control the quality of manufactured products and to monitor their performance in service. Because of its involvement in organizing training courses in all the common NDT methods in regional projects in Asia and the Pacific and Latin America and the Caribbean and in many country programmes, the Agency is aware of the importance of standardizing as far as possible the syllabi and training course notes used by the many experts who are involved in presenting the training courses. IAEA-TECDOC-628 ''Training Guidelines in Non-destructive Testing'' presents syllabi which were developed by an Agency executed UNDP project in Latin America and the Caribbean taking into account the developmental work done by the International Committee for Non-destructive Testing. Experience gained from using the radiography syllabi from TECDOC-628 at national and regional radiography training courses in the Agency executed UNDP project in Asia and the Pacific (RAS/86/073) showed that some guidance needed to be given to radiography experts engaged in teaching at these courses on the material which should be covered. The IAEA/UNDP Asia and Pacific Project National NDT Coordinators therefore undertook to prepare Radiography Training Course Notes which could be used by experts to prepare lectures for Level 1,2 and 3 radiography personnel. The notes have been expanded to cover most topics in a more complete manner than that possible at a Level 1, 2 or 3 training course and can now be used as source material for NDT personnel interested in expanding their knowledge of radiography. Refs, figs and tabs

  19. Detection of rib fractures in minor chest injuries: a comparison between ultrasonography and radiography performed on the same day

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Soo; Back, Chang Hee; Lee, Kyung Rae; Shin, Yun Hack; Whang, Yeong Seop; Jeong, Ku Young [Yeosu Baek Hospital, Yeosu (Korea, Republic of); Chung, Soo Hyun [NamWon Medical Center, NamWon (Korea, Republic of); Whang, Cheol Mog [Konyang University Hospital, Daejeon (Korea, Republic of)

    2007-04-15

    We wished to compare the ability of ultrasonography and radiography performed on the same day to detect rib fractures in minor chest injuries. Two hundred and fifteen patients with minor chest injuries were selected. Radiography and ultrasonography were performed on the same day with these patients. Chest wall pain was the only presenting symptom. Two radiologists performed ultrasonography. Fractures were identified by a disruption of the anterior margin of the rib and costal cartilage. The incidence and location of fractures and complications revealed by radiography and ultrasonography were compared. Radiographs revealed the presence of 70 rib fractures in 50 (23%) of 215 patients and ultrasonography revealed the presence of 203 rib fractures in 133 (62%) of 215 patients. Ultrasonography uniquely identified 133 rib fractures in 83 patients. Ultrasonography identified a 2.9 fold increase in the number of fractures in a 2.6 fold number of subjects as compared to radiography. Of the 203 sonographically detected fractures, 201 were located in the rib, one was located at the costochondral junction, and one in the costal cartilage. There were no complications seen by either radiography or ultrasonography. Ultrasonography reveals more fractures than those that may be overlooked on radiography for minor chest injuries.

  20. Detection of rib fractures in minor chest injuries: a comparison between ultrasonography and radiography performed on the same day

    International Nuclear Information System (INIS)

    Cho, Yong Soo; Back, Chang Hee; Lee, Kyung Rae; Shin, Yun Hack; Whang, Yeong Seop; Jeong, Ku Young; Chung, Soo Hyun; Whang, Cheol Mog

    2007-01-01

    We wished to compare the ability of ultrasonography and radiography performed on the same day to detect rib fractures in minor chest injuries. Two hundred and fifteen patients with minor chest injuries were selected. Radiography and ultrasonography were performed on the same day with these patients. Chest wall pain was the only presenting symptom. Two radiologists performed ultrasonography. Fractures were identified by a disruption of the anterior margin of the rib and costal cartilage. The incidence and location of fractures and complications revealed by radiography and ultrasonography were compared. Radiographs revealed the presence of 70 rib fractures in 50 (23%) of 215 patients and ultrasonography revealed the presence of 203 rib fractures in 133 (62%) of 215 patients. Ultrasonography uniquely identified 133 rib fractures in 83 patients. Ultrasonography identified a 2.9 fold increase in the number of fractures in a 2.6 fold number of subjects as compared to radiography. Of the 203 sonographically detected fractures, 201 were located in the rib, one was located at the costochondral junction, and one in the costal cartilage. There were no complications seen by either radiography or ultrasonography. Ultrasonography reveals more fractures than those that may be overlooked on radiography for minor chest injuries

  1. Comparison of neutron and high-energy X-ray dual-beam radiography for air cargo inspection

    International Nuclear Information System (INIS)

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

    2008-01-01

    Dual-beam radiography techniques utilising various combinations of high-energy X-rays and neutrons are attractive for screening bulk cargo for contraband such as narcotics and explosives. Dual-beam radiography is an important enhancement to conventional single-beam X-ray radiography systems in that it provides additional information on the composition of the object being imaged. By comparing the attenuations of transmitted dual high-energy beams, it is possible to build a 2D image, colour coded to indicate material. Only high-energy X-rays, gamma-rays and neutrons have the required penetration to screen cargo containers. This paper reviews recent developments and applications of dual-beam radiography for air cargo inspection. These developments include dual high-energy X-ray techniques as well as fast neutron and gamma-ray (or X-ray) radiography systems. High-energy X-ray systems have the advantage of generally better penetration than neutron systems, depending on the material being interrogated. However, neutron systems have the advantage of much better sensitivity to material composition compared to dual high-energy X-ray techniques. In particular, fast neutron radiography offers the potential to discriminate between various classes of organic material, unlike dual energy X-ray techniques that realistically only offer the ability to discriminate between organic and metal objects

  2. Comparison of scatter rejection and low-contrast performance of scan equalization digital radiography (SEDR), slot-scan digital radiography, and full-field digital radiography systems for chest phantom imaging

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xinming; Shaw, Chris C.; Lai, Chao-Jen; Wang Tianpeng [Department of Imaging Physics, Digital Imaging Research Laboratory, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030-4009 (United States)

    2011-01-15

    Purpose: To investigate and compare the scatter rejection properties and low-contrast performance of the scan equalization digital radiography (SEDR) technique to the slot-scan and conventional full-field digital radiography techniques for chest imaging. Methods: A prototype SEDR system was designed and constructed with an a-Se flat-panel (FP) detector to improve image quality in heavily attenuating regions of an anthropomorphic chest phantom. Slot-scanning geometry was used to reject scattered radiation without attenuating primary x rays. The readout scheme of the FP was modified to erase accumulated scatter signals prior to image readout. A 24-segment beam width modulator was developed to regulate x-ray exposures regionally and compensate for the low x-ray flux in heavily attenuating regions. To measure the scatter-to-primary ratios (SPRs), a 2 mm thick lead plate with a 2-D array of aperture holes was used to measure the primary signals, which were then subtracted from those obtained without the lead plate to determine scatter components. A 2-D array of aluminum beads (3 mm in diameter) was used as the low-contrast objects to measure the contrast ratios (CRs) and contrast-to-noise ratios (CNRs) for evaluating the low-contrast performance in chest phantom images. A set of two images acquired with the same techniques were subtracted from each other to measure the noise levels. SPRs, CRs, and CNRs of the SEDR images were measured in four anatomical regions of chest phantom images and compared to those of slot-scan images and full-field images acquired with and without antiscatter grid. Results: The percentage reduction of SPR (percentage of SPRs reduced with scatter removal/rejection methods relative to that for nongrid full-field imaging) averaged over four anatomical regions was measured to be 80%, 83%, and 71% for SEDR, slot-scan, and full-field with grid, respectively. The average CR over four regions was found to improve over that for nongrid full

  3. Comparison of scatter rejection and low-contrast performance of scan equalization digital radiography (SEDR), slot-scan digital radiography, and full-field digital radiography systems for chest phantom imaging

    International Nuclear Information System (INIS)

    Liu Xinming; Shaw, Chris C.; Lai, Chao-Jen; Wang Tianpeng

    2011-01-01

    Purpose: To investigate and compare the scatter rejection properties and low-contrast performance of the scan equalization digital radiography (SEDR) technique to the slot-scan and conventional full-field digital radiography techniques for chest imaging. Methods: A prototype SEDR system was designed and constructed with an a-Se flat-panel (FP) detector to improve image quality in heavily attenuating regions of an anthropomorphic chest phantom. Slot-scanning geometry was used to reject scattered radiation without attenuating primary x rays. The readout scheme of the FP was modified to erase accumulated scatter signals prior to image readout. A 24-segment beam width modulator was developed to regulate x-ray exposures regionally and compensate for the low x-ray flux in heavily attenuating regions. To measure the scatter-to-primary ratios (SPRs), a 2 mm thick lead plate with a 2-D array of aperture holes was used to measure the primary signals, which were then subtracted from those obtained without the lead plate to determine scatter components. A 2-D array of aluminum beads (3 mm in diameter) was used as the low-contrast objects to measure the contrast ratios (CRs) and contrast-to-noise ratios (CNRs) for evaluating the low-contrast performance in chest phantom images. A set of two images acquired with the same techniques were subtracted from each other to measure the noise levels. SPRs, CRs, and CNRs of the SEDR images were measured in four anatomical regions of chest phantom images and compared to those of slot-scan images and full-field images acquired with and without antiscatter grid. Results: The percentage reduction of SPR (percentage of SPRs reduced with scatter removal/rejection methods relative to that for nongrid full-field imaging) averaged over four anatomical regions was measured to be 80%, 83%, and 71% for SEDR, slot-scan, and full-field with grid, respectively. The average CR over four regions was found to improve over that for nongrid full

  4. COMPARISONS AMONG RADIOGRAPHY, ULTRASONOGRAPHY AND COMPUTED TOMOGRAPHY FOR EX VIVO CHARACTERIZATION OF STIFLE OSTEOARTHRITIS IN THE HORSE.

    Science.gov (United States)

    De Lasalle, Julie; Alexander, Kate; Olive, Julien; Laverty, Sheila

    2016-09-01

    A better understanding of imaging characteristics of equine stifle osteoarthritis (OA) may allow earlier detection and improve prognosis. Objectives of this ex vivo, prospective, methods comparison study were to (1) describe the location and severity of naturally acquired OA lesions in the equine stifle using ultrasound (US), radiography (XR), computed tomography (CT), and macroscopic evaluation (ME); (2) compare the diagnostic performance of each imaging modality with ME; and (3) describe subchondral bone mineral density (BMD) in equine stifle joints with OA using CT. Radiographic, CT, and US evaluations were performed on 23 equine cadaver stifles and compared with ME. Significant associations were found between osteophyte global scores for all imaging modalities (CT, P ˂ 0.0001; XR, P = 0.005; US, P = 0.04) vs. ME osteophyte global scores. Osteophytes were detected most frequently in the medial femorotibial (MFT) joint. A specific pattern of osteophytes was observed, with a long ridge of new bone at the insertion of the MFT joint capsule cranially on the medial femoral condyle. A novel caudo-10°proximo-5°lateral-cranio-disto-medial oblique radiographic projection was helpful for detection of intercondylar osteophytes. Multiplanar CT reformatted images were helpful for characterizing all osteophytes. Osteophyte grades at most sites did not differ among modalities. Low sensitivity/specificity for subchondral bone sclerosis and flattening of femoral condyles suggested that these signs may not be reliable radiographic and CT indicators of equine stifle OA. Equine stifle OA was associated with a decrease in BMD and specific sites of focal subchondral bone resorption/cyst formation were found in some specimens. © 2016 American College of Veterinary Radiology.

  5. Dental radiography

    International Nuclear Information System (INIS)

    Shekhdar, J.

    1993-01-01

    Dental radiography must comply with the same regulations with which conventional radiography complies. Radiation doses to individual patients are low but, because of the large number of patients X-rayed, the collective dose to the population is not negligible. Care in siting and regular maintenance of the equipment will reduce doses to both staff and patients. To produce X-ray films with a good image quality using a low radiation dose requires attention to film processing; this is often a neglected area. (Author)

  6. Proton beam dosimetry: a comparison between a plastic scintillator, ionization chamber and faraday cup

    International Nuclear Information System (INIS)

    Ghergherehchi, Mitra; Afarideh, Hossein; Mohammadzadeh, Ahmad; Boghrati, Behzad; Ghannadi, Mohammad; Aslani, Golam Reza

    2010-01-01

    In this study, a comparison was made between a plastic scintillator (BC400), a Faraday Cup (FC) and an ionization chamber (IC) used for routine proton dosimetry. Thin scintillators can be applied to proton dosimetry and consequently to proton therapy as relative dosimeters because of their water-equivalent nature, high energy-light conversion efficiency, low dimensions and good proportionality to the absorbed dose at low stopping powers. To employ such scintillators as relative dosimeters in proton therapy, the corrective factors must be applied to correct the quenching luminescence at the Bragg peak. A fine linear proportionality between the luminescence light yield Y and the proton flux in a thin (0.5 mm) scintillator for the 20 and 30 MeV proton beams were observed. The experimental peak/plateau ratios of Bragg Curve for 2, 1 and 0.5 mm scintillators with an accuracy of 0.5% were obtained to be 1.87, 1.91 and 2.30, respectively. With combination of the Markus chamber and the CR-39 detector, the peak/plateau ratio was improved to 3.26. The obtained data of the luminescence yield as a function of the specific energy loss is in agreement with the Craun-Birk's theory. Results show that the FC and Markus ionization chamber are in agreement within 4%, while the FC gives a lower dose evaluation. For a defined beam, the data for the fluence measurements are reproducible within a good accuracy. (author)

  7. Comparison of digital tomosynthesis and chest radiography for the detection of pulmonary nodules: systematic review and meta-analysis.

    Science.gov (United States)

    Kim, Jun H; Lee, Kyung H; Kim, Kyoung-Tae; Kim, Hyun J; Ahn, Hyeong S; Kim, Yeo J; Lee, Ha Y; Jeon, Yong S

    2016-12-01

    To compare the diagnostic accuracy of digital tomosynthesis (DTS) with that of chest radiography for the detection of pulmonary nodules by meta-analysis. A systematic literature search was performed to identify relevant original studies from 1 January 1 1976 to 31 August 31 2016. The quality of included studies was assessed by quality assessment of diagnostic accuracy studies-2. Per-patient data were used to calculate the sensitivity and specificity and per-lesion data were used to calculate the detection rate. Summary receiver-operating characteristic curves were drawn for pulmonary nodule detection. 16 studies met the inclusion criteria. 1017 patients on a per-patient basis and 2159 lesions on a per-lesion basis from 16 eligible studies were evaluated. The pooled patient-based sensitivity of DTS was 0.85 [95% confidence interval (CI) 0.83-0.88] and the specificity was 0.95 (0.93-0.96). The pooled sensitivity and specificity of chest radiography were 0.47 (0.44-0.51) and 0.37 (0.34-0.40), respectively. The per-lesion detection rate was 2.90 (95% CI 2.63-3.19). DTS has higher diagnostic accuracy than chest radiography for detection of pulmonary nodules. Chest radiography has low sensitivity but similar specificity, comparable with that of DTS. Advances in knowledge: DTS has higher diagnostic accuracy than chest radiography for the detection of pulmonary nodules.

  8. Dosimetric comparison of photon and proton treatment techniques for chondrosarcoma of thoracic spine

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Poonam, E-mail: yadav@humonc.wisc.edu [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, WI (United States); University of Wisconsin Riverview Cancer Center, Wisconsin Rapids, WI (United States); Paliwal, Bhudatt R. [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Kozak, Kevin [Department of Human Oncology, University of Wisconsin, Madison, WI (United States)

    2013-10-01

    Chondrosarcomas are relatively radiotherapy resistant, and also delivering high radiation doses is not feasible owing to anatomic constraints. In this study, the feasibility of helical tomotherapy for treatment of chondrosarcoma of thoracic spine is explored and compared with other available photon and proton radiotherapy techniques in the clinical setting. A patient was treated for high-grade chondrosarcoma of the thoracic spine using tomotherapy. Retrospectively, the tomotherapy plan was compared with intensity-modulated radiation therapy, dynamic arc photon therapy, and proton therapy. Two primary comparisons were made: (1) comparison of normal tissue sparing with comparable target volume coverage (plan-1), and (2) comparison of target volume coverage with a constrained maximum dose to the cord center (plan-2). With constrained target volume coverage, proton plans were found to yield lower mean doses for all organs at risk (spinal cord, esophagus, heart, and both lungs). Tomotherapy planning resulted in the lowest mean dose to all organs at risk amongst photon-based methods. For cord dose constrained plans, the static-field intensity-modulated radiation therapy and dynamic arc plans resulted target underdosing in 20% and 12% of planning target volume2 volumes, respectively, whereas both proton and tomotherapy plans provided clinically acceptable target volume coverage with no portion of planning target volume2 receiving less than 90% of the prescribed dose. Tomotherapy plans are comparable to proton plans and produce superior results compared with other photon modalities. This feasibility study suggests that tomotherapy is an attractive alternative to proton radiotherapy for delivering high doses to lesions in the thoracic spine.

  9. Dosimetric comparison of photon and proton treatment techniques for chondrosarcoma of thoracic spine

    International Nuclear Information System (INIS)

    Yadav, Poonam; Paliwal, Bhudatt R.; Kozak, Kevin

    2013-01-01

    Chondrosarcomas are relatively radiotherapy resistant, and also delivering high radiation doses is not feasible owing to anatomic constraints. In this study, the feasibility of helical tomotherapy for treatment of chondrosarcoma of thoracic spine is explored and compared with other available photon and proton radiotherapy techniques in the clinical setting. A patient was treated for high-grade chondrosarcoma of the thoracic spine using tomotherapy. Retrospectively, the tomotherapy plan was compared with intensity-modulated radiation therapy, dynamic arc photon therapy, and proton therapy. Two primary comparisons were made: (1) comparison of normal tissue sparing with comparable target volume coverage (plan-1), and (2) comparison of target volume coverage with a constrained maximum dose to the cord center (plan-2). With constrained target volume coverage, proton plans were found to yield lower mean doses for all organs at risk (spinal cord, esophagus, heart, and both lungs). Tomotherapy planning resulted in the lowest mean dose to all organs at risk amongst photon-based methods. For cord dose constrained plans, the static-field intensity-modulated radiation therapy and dynamic arc plans resulted target underdosing in 20% and 12% of planning target volume2 volumes, respectively, whereas both proton and tomotherapy plans provided clinically acceptable target volume coverage with no portion of planning target volume2 receiving less than 90% of the prescribed dose. Tomotherapy plans are comparable to proton plans and produce superior results compared with other photon modalities. This feasibility study suggests that tomotherapy is an attractive alternative to proton radiotherapy for delivering high doses to lesions in the thoracic spine

  10. The role of whole body spiral CT in the primary work-up of polytrauma patients - comparison with conventional radiography and abdominal sonography

    International Nuclear Information System (INIS)

    Albrecht, T.; Schlippenbach, J. von; Wolf, K.J.; Stahel, P.F.; Ertel, W.

    2004-01-01

    Purpose: To evaluate the role of routine 'whole body spiral CT' in the primary work-up of polytrauma patients for injuries of the thorax, abdomen and spine, and to compare the results with those of conventional radiography of the chest and spine and abdominal ultrasound. Materials and Methods: Fifty consecutive polytrauma patients underwent contrast-enhanced single slice spiral CT (5 mm collimation) from the vertex to the floor of the pelvis as part of the primary work-up after emergency room admission. Overlapping high resolution sections and sagittal reformations of the spine were obtained. Reports of additional chest radiographs (n=43), abdominal ultrasound examinations (n=47) and spine radiographs (n=36) performed in the emergency room were available for retrospective comparison. The 'final diagnoses', which served as the standard of reference, were taken from the patients' records using all information that became available until discharge or death, such as findings from further imaging, surgery and autopsy. Results: CT showed 109 (97%) of 112 thoracic and abdominal soft-tissue injuries. Relevant injuries missed were an early splenic laceration and an early pelvic hematoma, both of which became clinically apparent several hours later. There were 4 false positive CT findings. Conventional chest radiography demonstrated only 20% of thoracic and sonography 22% of abdominal injuries. Chest radiography and sonography produced 2 false-positive findings each. CT showed 66 (87%) of 76 vertebral fractures including all 19 unstable ones. CT missed 5 anterior vertebral body and 5 spinous/transverse process fractures. Conventional radiography found 71% of vertebral fractures including only 50% of the unstable one. (orig.)

  11. Neutron induced electron radiography

    International Nuclear Information System (INIS)

    Andrade, Marcos Leandro Garcia

    2008-01-01

    In the present paper a new radiography technique, the 'Neutron Induced Electron Radiography' - NIER, to inspect low thickness samples on the order of micra, has been developed. This technique makes use of low energy electrons as penetrating radiation generated from metallic gadolinium screens when irradiated by thermal neutrons. The conditions to obtain the best image for the conventional X-ray film Kodak-AA were determined by using a digital system to quantify the darkening level of the film. The irradiations have been performed at a radiography equipment installed at the beam-hole no. 8 of the 5 MW IEA-R1 nuclear research reactor of IPEN-CNEN/SP. The irradiation time to obtain the best radiography was 100 seconds and for such condition the technique was able to discern 1 μm in 24 μm of aluminum at a resolution of 32 μm. By visual comparison the images obtained by the NIER shown a higher quality when compared with the ones from other usual techniques the make use of electrons a penetrating radiation and films for image registration. Furthermore the use of the digital system has provided a smaller time for data acquisition and data analysis as well as an improvement in the image visualization. (author)

  12. Industrial radiography

    International Nuclear Information System (INIS)

    Aloni, A.; Magal, O.

    1992-02-01

    This publication is meant to be a manual for industrial radiography. As such the manual concentrates on the practical aspects, presenting existing radiographic system and techniques of operation to satisfy specified quality requirements. The manual also reviews the safety aspect of performing radiographic work. (author) systems

  13. Radiography technique

    Energy Technology Data Exchange (ETDEWEB)

    Panaiotov, L N

    1951-10-23

    A new method of hollow articles radiography is presented enabling to eliminate shortcomings coupled with medical personnel irradiation when the ampoule incorporating radioactive substance is removed from the protective container and adjusted in the article. The method presented permits to transport the ampoule from the protective container immediately into the inner cavity of the article.

  14. Skull Radiography

    Science.gov (United States)

    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, ...

  15. Comparison of computerized digital and film-screen radiography: response to variation in imaging kVp

    Energy Technology Data Exchange (ETDEWEB)

    Broderick, N J; Long, B; Dreesen, R G; Cohen, M D; Cory, D A [Riley Hospital for Children, Indiana Univ. School of Medicine, Indianapolis, IN (United States). Dept. of Radiology; Katz, B P; Kalasinski, L A [Regenstreif Inst., Indiana Univ. School of Medicine, Indianapolis, IN (United States). Dept. of Medicine

    1992-09-01

    A controlled prospective study, in an animal model chosen to simulate portable neonatal radiography, was performed to compare the response of the Philips Computed Radiography (CR) system and conventional 200 speed film-screen (FS) to variation in imaging kVp. Acceptable images were obtained on the CR system over a very wide kVp range. In contrast the FS system produced acceptable images over a narrow kVp range. This ability suggests that the CR system should eliminate the need for repeat examinations in cases where a suboptimal kVp setting would have resulted in an unacceptable FS image. CR technology should therefore be ideally suited to portable radiography especially in situations where selection of correct exposure factors is difficult as in the neonatal nursery. (orig.).

  16. Comparison of computerized digital and film-screen radiography: response to variation in imaging kVp

    International Nuclear Information System (INIS)

    Broderick, N.J.; Long, B.; Dreesen, R.G.; Cohen, M.D.; Cory, D.A.; Katz, B.P.; Kalasinski, L.A.

    1992-01-01

    A controlled prospective study, in an animal model chosen to simulate portable neonatal radiography, was performed to compare the response of the Philips Computed Radiography (CR) system and conventional 200 speed film-screen (FS) to variation in imaging kVp. Acceptable images were obtained on the CR system over a very wide kVp range. In contrast the FS system produced acceptable images over a narrow kVp range. This ability suggests that the CR system should eliminate the need for repeat examinations in cases where a suboptimal kVp setting would have resulted in an unacceptable FS image. CR technology should therefore be ideally suited to portable radiography especially in situations where selection of correct exposure factors is difficult as in the neonatal nursery. (orig.)

  17. A comparison of radiography, computed tomography, and magnetic resonance imaging for the diagnosis of palmar process fractures in foals

    International Nuclear Information System (INIS)

    Kaneps, A.J.; Koblik, P.D.; Freeman, D.M.; Pool, R.R.; O'Brien, T.R.

    1995-01-01

    The relative sensitivity of radiography, computed tomography, and magnetic resonance imaging for detecting palmar process fractures of the distal phalanx in foals was determined and the imaging findings were compared with histomorphologic evaluations of the palmar processes. Compared to radiography, computed tomography and magnetic resonance imaging did not improve the sensitivity for detection of palmar process fractures. Statistical agreement for palmar process fracture diagnosis was excellent among the three imaging modalities. Histomorphologic evaluations were more sensitive for diagnosis of palmar process fracture than any of the imaging modalities. Three-dimensional image reconstructions and volume measurements of distal phalanges and palmar process fracture fragments from computed tomography studies provided more complete anatomical information than radiography. Magnetic resonance imaging confirmed that the deep digital flexor tendon insertion on the distal phalanx is immediately axial to the site where palmar process fractures occur, and differentiated cartilage, bone, and soft tissue structures of the hoof

  18. Comparison of clinical and physical measures of image quality in chest and pelvis computed radiography at different tube voltages

    International Nuclear Information System (INIS)

    Sandborg, Michael; Tingberg, Anders; Ullman, Gustaf; Dance, David R.; Alm Carlsson, Gudrun

    2006-01-01

    The aim of this work was to study the dependence of image quality in digital chest and pelvis radiography on tube voltage, and to explore correlations between clinical and physical measures of image quality. The effect on image quality of tube voltage in these two examinations was assessed using two methods. The first method relies on radiologists' observations of images of an anthropomorphic phantom, and the second method was based on computer modeling of the imaging system using an anthropomorphic voxel phantom. The tube voltage was varied within a broad range (50-150 kV), including those values typically used with screen-film radiography. The tube charge was altered so that the same effective dose was achieved for each projection. Two x-ray units were employed using a computed radiography (CR) image detector with standard tube filtration and antiscatter device. Clinical image quality was assessed by a group of radiologists using a visual grading analysis (VGA) technique based on the revised CEC image criteria. Physical image quality was derived from a Monte Carlo computer model in terms of the signal-to-noise ratio, SNR, of anatomical structures corresponding to the image criteria. Both the VGAS (visual grading analysis score) and SNR decrease with increasing tube voltage in both chest PA and pelvis AP examinations, indicating superior performance if lower tube voltages are employed. Hence, a positive correlation between clinical and physical measures of image quality was found. The pros and cons of using lower tube voltages with CR digital radiography than typically used in analog screen-film radiography are discussed, as well as the relevance of using VGAS and quantum-noise SNR as measures of image quality in pelvis and chest radiography

  19. Comparison of Radiography, Laser Fluorescence, and Visual Examination in Diagnosing Incipient OcclusalCaries of Permanent First Molars

    Directory of Open Access Journals (Sweden)

    Zahra Bahrololoomi

    2015-10-01

    Full Text Available Objectives: Early diagnosis of incipient and non cavitated carious lesions is crucial for performing preventive treatments. The aim of this study was to compare the effi- ciency of three diagnostic methods of bite-wing radiography, DIAGNOdent, and visu- al examination in diagnosing the incipient occlusal caries of permanent first molars.Materials and Methods:  In this diagnostic cross-sectional study, 109 premanent first molar teeth of 31 patients aged 7-13 years were examined visually by bite-wing radi- ograghy, and DIAGNOdent. Scoring of visual and radiography examinations were based on the Ekstrand classification. Visual examination after pit and fissure opening was used as the gold standard. ROC curve (Receiver Operating Characteristics was used to define the best cut-off point for DIAGNodent compareing with gold standard and inter-examiner reproductibility of visual, radiography were assessed using Kappa test and ICC (Intraclass Correlation wase used for DIAGNOdent values.Results: The sensitivity of detecting caries that had extended into the enamel was 81.4%, 86.3%, and 81.4% for visual examination, DIAGNOdent, and radiography, respectively. Moreover, the specificity was 100%, 71.4%, and 100% for visual obser- vation, DIAGNOdent, and radiography, respectively in the enamel. The Kappa index for inter-examiner correlation was 0.7 and 0.8 for visual examination and radiog- raphy, respectively. The ICC (Intraclass Correlation was 0.98 for the values read by DIAGNOdent.Conclusion: Visual examination is rendered as the first choice in the diagnosis of in- cipient caries. In suspicious cases, radiography and laser DIAGNOdent can be used as adjunct procedures.

  20. Neutron radiography

    International Nuclear Information System (INIS)

    Alaa eldin, M.T.

    2011-01-01

    The digital processing of the neutron radiography images gives the possibility for data quantification. In this case an exact relation between the measured neutron attenuation and the real macroscopic attenuation coefficient for every point of the sample is required. The assumption that the attenuation of the neutron beam through the sample is exponential is valid only in an ideal case where a monochromatic beam, non scattering sample and non background contribution are assumed. In the real case these conditions are not fulfilled and in dependence on the sample material we have more or less deviation from the exponential attenuation law. Because of the high scattering cross-sections of hydrogen (σs=80.26 barn) for thermal neutrons, the problem with the scattered neutrons at quantitative radiography investigations of hydrogenous materials (as PE, Oil, H 2 O, etc) is not trivial. For these strong scattering materials the neutron beam attenuation is no longer exponential and a dependence of the macroscopic attenuation coefficient on the material thickness and on the distance between the sample and the detector appears. When quantitative radiography (2 D) or tomography investigations (3 D) are performed, some image correction procedures for a description of the scattering effect are required. This thesis presents a method that can be used to enhance the neutron radiography image for objects with high scattering materials like hydrogen, carbon and other light materials. This method uses the Monte Carlo code, MCNP5, to simulate the neutron radiography process and get the flux distribution for each pixel of the image and determine the scattered neutrons distribution that causes the image blur and then subtract it from the initial image to improve its quality.

  1. Subtraction radiography and computer assisted densitometric analyses of standardized radiographs. A comparison study with /sup 125/I absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Ortmann, L.F.; Dunford, R.; McHenry, K.; Hausmann, E.

    1985-01-01

    A standardized radiographic series of incrementally increasing alveolar crestal defects in skulls were subjected to analyses by subtraction radiography and computer assisted quantitative densitometric analysis. Subjects were able to detect change using subtraction radiography in alveolar bone defects with bone loss in the range of 1-5 percent as measured by /sup 125/I absorptiometry. Quantitative densitometric analyses utilizing radiographic pairs adjusted for differences in contrast (gamma corrected) can be used to follow longitudinal changes at a particular alveolar bone site. Such measurements correlate with change observed by /sup 125/I absorptiometry (r=0.82-0.94). (author).

  2. Progress in digital radiography

    International Nuclear Information System (INIS)

    Cappelle, A.

    2016-01-01

    Because of its practical aspect digital radiography is more and more used in the industrial sector. There are 2 kinds of digital radiography. First, the 'computed radiography' that uses a photon-stimulated screen, and after radiation exposure this screen must be read by an analyser to get a digit image. The second type is the 'direct radiography' that allows one to get a digit radiograph of the object directly. Digital radiography uses the same radioactive nuclides as radiography with silver films: cobalt, iridium or selenium. The spatial resolution of digital radiography is less good than with classical silver film radiography but digital radiography offers a better visual contrast. (A.C.)

  3. Thorium-uranium fission radiography

    Science.gov (United States)

    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.

  4. Comparison of cone - beam computed tomography and intraoral radiography in detection of recurrent caries under composite restorations

    Energy Technology Data Exchange (ETDEWEB)

    Kasraei, Shahin; Shokri, Abbas; Poorolajal, Jalal; Rahmani, Hamid, E-mail: Dr.a.shokri@gmail.com [Hamadan University of Medical Sciences Hamadan (Iran, Islamic Republic of); Khajeh, Samira [Kurdistan University of Medical Sciences, Sanandaj (Iran, Islamic Republic of)

    2017-01-15

    Secondary caries is the most common cause of dental restoration failures. This study aimed to compare the diagnostic accuracy of conventional and digital intraoral radiography and cone beam computed tomography (CBCT) for detection of recurrent caries around composite restorations mesio-occluso-distal (MOD) cavities were prepared using bur on 45 extracted sound human molar teeth. The teeth were divided into 3 groups. In the control group, cavities were restored with composite resin after etching and bonding (n=15). In Group 2, 500-μm thick wax was placed over the buccal, lingual and gingival walls and the cavities were restored with composite resin. Group 3 specimens were subjected to pH cycling and artificial caries were created on the buccal, lingual and gingival walls. The cavities were restored with composite. Conventional and digital photo-stimulable phosphor (PSP; Optime) radiographs and two CBCTs images (NewTom 3G and Cranex 3D) were obtained from them. Presence or absence of caries in the cavity walls was assessed on these images. Data were analyzed using Kappa statistic. The diagnostic accuracy of CBCT was significantly higher than that of digital and conventional intraoral radiography (p<0.05). The accuracy was 0.83, 0.78, 0.55 and 0.49 for CBCT Cranex 3D, CBCT NewTom 3G, conventional and digital intraoral radiography, respectively. CBCT has a higher diagnostic accuracy than digital and conventional intraoral radiography for detection of secondary caries around composite restorations. (author)

  5. Occupational exposure in Greek industrial radiography laboratories (2004-2006) and comparison of doses with other industrial applications

    International Nuclear Information System (INIS)

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

    2008-01-01

    Full text: In this study the Mean Annual Dose (MAD) of all industrial radiography workers in Greece for the time period 2004-2006 is evaluated and correlated to the practice and type of equipment used. All data used in this study come from the National Dose Registry Information System of the Greek Atomic Energy Commission. The present study constitutes the follow up of two previous studies, where a Dose Constraint (DC) for industrial radiography in Greece, equal to 4.0mSv was introduced for the first time. The introduction and systematic use of a dynamic DC value aims to optimize common working practices through a continuous decrease of occupational doses. In the current work a further decrease in the industrial radiography personnel doses is observed and the factors leading to this result are analyzed. Finally, the estimated MAD value for exposed workers in industrial radiography is compared to the ones corresponding to workers in other industrial applications involving the use of ionizing radiation

  6. Comparison of radiography, computed tomography and magnetic resonance imaging in the detection of sacroiliitis accompanying ankylosing spondylitis

    International Nuclear Information System (INIS)

    Yu, Wei; Feng Feng; Yang Hongzen; Jiang Ming; Dion, E.; Genant, H.K.

    1998-01-01

    Objective. To compare magnetic resonance (MR) imaging, computed tomography (CT), and radiography in the detection of sacroiliitis accompanying ankylosing spondylitis (AS). Design and subjects. Nine volunteers and 24 patients were recruited. Radiography, CT, and MR imaging were completed within a 1-week period in 24 patients with AS. In precontrast MR examination, spin-echo T1, fast spin-echo T2, and gradient echo with rephasing T2* images were obtained without fat saturation using a 0.3-T imager for all volunteers and patients. Postcontrast MR examination was performed using the same precontrast SE T1 sequence for patients with AS. Results and conclusions. MR imaging directly showed the normal cartilage in all 16 sacroiliac joints of the 8 volunteers. In the 24 patients with AS, cartilage abnormalities were observed in 42 sacroiliac joints. More diagnoses of sacroiliitis were made using MR and CT imaging than using radiography (P<0.001). Therefore, low-field-strength MR can be useful in detecting early sacroiliitis in patients with AS. MR imaging was able to reveal early cartilage changes and bone marrow edema, which could not be found by either CT or radiography. (orig.)

  7. A comparison of magnetic resonance imaging, sonography, and radiography of the hand in patients with early rheumatoid arthritis

    NARCIS (Netherlands)

    Hoving, Jan Lucas; Buchbinder, Rachelle; Hall, Stephen; Lawler, Gary; Coombs, Peter; McNealy, Stephen; Bird, Paul; Connell, David

    2004-01-01

    OBJECTIVE: As therapy for rheumatoid arthritis (RA) becomes more effective, more sensitive imaging methods are required to assess disease activity and joint damage. We compared magnetic resonance imaging (MRI), sonography, and radiography for assessment of disease activity for the detection of bony

  8. Comparison of cone - beam computed tomography and intraoral radiography in detection of recurrent caries under composite restorations

    International Nuclear Information System (INIS)

    Kasraei, Shahin; Shokri, Abbas; Poorolajal, Jalal; Rahmani, Hamid; Khajeh, Samira

    2017-01-01

    Secondary caries is the most common cause of dental restoration failures. This study aimed to compare the diagnostic accuracy of conventional and digital intraoral radiography and cone beam computed tomography (CBCT) for detection of recurrent caries around composite restorations mesio-occluso-distal (MOD) cavities were prepared using bur on 45 extracted sound human molar teeth. The teeth were divided into 3 groups. In the control group, cavities were restored with composite resin after etching and bonding (n=15). In Group 2, 500-μm thick wax was placed over the buccal, lingual and gingival walls and the cavities were restored with composite resin. Group 3 specimens were subjected to pH cycling and artificial caries were created on the buccal, lingual and gingival walls. The cavities were restored with composite. Conventional and digital photo-stimulable phosphor (PSP; Optime) radiographs and two CBCTs images (NewTom 3G and Cranex 3D) were obtained from them. Presence or absence of caries in the cavity walls was assessed on these images. Data were analyzed using Kappa statistic. The diagnostic accuracy of CBCT was significantly higher than that of digital and conventional intraoral radiography (p<0.05). The accuracy was 0.83, 0.78, 0.55 and 0.49 for CBCT Cranex 3D, CBCT NewTom 3G, conventional and digital intraoral radiography, respectively. CBCT has a higher diagnostic accuracy than digital and conventional intraoral radiography for detection of secondary caries around composite restorations. (author)

  9. SU-E-I-15: Comparison of Radiation Dose for Radiography and EOS in Adolescent Scoliosis Patients

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, B; Walz-Flannigan, A [Mayo Clinic, Rochester, MN (United States)

    2014-06-01

    Purpose: To estimate patient radiation dose for whole spine imaging using EOS, a new biplanar slot-scanning radiographic system and compare with standard scoliosis radiography. Methods: The EOS imaging system (EOS Imaging, Paris, France) consists of two orthogonal x-ray fan beams which simultaneously acquire frontal and lateral projection images of a standing patient. The patient entrance skin air kerma was measured for each projection image using manufacturer-recommended exposure parameters for spine imaging. Organ and effective doses were estimated using a commercially-available Monte Carlo simulation program (PCXMC, STUK, Radiation and Nuclear Safety Authority, Helsinki, Finland) for a 15 year old mathematical phantom model. These results were compared to organ and effective dose estimated for scoliosis radiography using computed radiography (CR) with standard exposure parameters obtained from a survey of pediatric radiographic projections. Results: The entrance skin air kerma for EOS was found to be 0.18 mGy and 0.33 mGy for posterior-anterior (PA) and lateral projections, respectively. This compares to 0.76 mGy and 1.4 mGy for CR, PA and lateral projections. Effective dose for EOS (PA and lateral projections combined) is 0.19 mSv compared to 0.51 mSv for CR. Conclusion: The EOS slot-scanning radiographic system allows for reduced patient radiation dose in scoliosis patients as compared to standard CR radiography.

  10. Comparison of cone beam computed tomography and conventional panoramic radiography in assessing the topographic relationship between the mandibular canal and impacted third molars

    International Nuclear Information System (INIS)

    Choi, Hyung Soo; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan

    2008-01-01

    To assess the diagnostic accuracy and value in an imaging technique field through the comparison of cone beam computed tomography and conventional panoramic radiography in assessing the topographic relationship between the mandibular canal and impacted third molars. Participants consisted of 100 patients offered the images through cone beam computed tomography and panoramic radiography. PSR-9000TM Dental CT system (Asahi Roentgen Ind. Co., Ltd, Japan) was used as the unit of cone beam computed tomography. CE-II (Asahi Roentgen Ind. Co., Ltd, Japan) and Pro Max (Planmeca Oy, Finland) were used as the unit of panoramic radiography. The images obtained through panoramic radiography were classified into 3 types according to the distance between mandibular canal and root of mandibular third molar. And they were classified into 4 types according to the proximity of radiographic feature. The images obtained through cone beam computed tomography based on the classification above were classified into 4 types according to the location between the mandibular canal and the root and were analyzed. And they were classified into buccal, inferior, lingual, and between roots, according to the location between mandibular canal and root. The data were statistically analyzed and estimated by x2-test. 1. There was no statistical significance according to 3 types (type I, type II, type III) through CBCT. 2. The results of 4 types (type A, type B, type C, type D) through CBCT were as high prevalence of CBCT 1 in type A, CBCT 2 in type B, CBCT 3 in type C, and CBCT1 in type D and those of which showed statistical significance (P value=0.03). 3. The results according to location between mandibular canal and root through CBCT recorded each 49, 25, 17, 9 as buccal, inferior, lingual, between roots. When estimating the mandibular canal and the roots through the panoramic radiography, it could be difficult to drive the views of which this estimation was considerable. Thus it is required to

  11. Digital radiography

    International Nuclear Information System (INIS)

    Brody, W.R.

    1984-01-01

    Digital Radiography begins with an orderly introduction to the fundamental concepts of digital imaging. The entire X-ray digital imagining system is described, from an overall characterization of image quality to specific components required for a digital radiographic system. Because subtraction is central to digital radiographic systems, the author details the use of various subtraction methods for image enhancement. Complex concepts are illustrated with numerous examples and presented in terms that can readily be understood by physicians without an advanced mathematics background. The second part of the book discusses implementations and applications of digital imagining systems based on area and scanned detector technologies. This section includes thorough coverage of digital fluoroscopy, scanned projection radiography, and film-based digital imaging systems, and features a state-of-the-art synopsis of the applications of digital subtraction angiography. The book concludes with a timely assessment of anticipated technological advances

  12. Ambulating radiography

    International Nuclear Information System (INIS)

    Magnusson, K.

    1989-01-01

    Strong gamme or X-ray sources are utilized for non-destructive testing of i.e. bridges. The activities involve certain risks of accident that might lead to serious injuries caused by radiation. The National Institute of Radiation Protection has during the laste decade greatly yhe inspection rate in this area. It has today made controls of most enterprieses running ambulating radiography. (O.S.)

  13. Computed radiography

    International Nuclear Information System (INIS)

    Pupchek, G.

    2004-01-01

    Computed radiography (CR) is an image acquisition process that is used to create digital, 2-dimensional radiographs. CR employs a photostimulable phosphor-based imaging plate, replacing the standard x-ray film and intensifying screen combination. Conventional radiographic exposure equipment is used with no modification required to the existing system. CR can transform an analog x-ray department into a digital one and eliminates the need for chemicals, water, darkrooms and film processor headaches. (author)

  14. Magnification radiography

    International Nuclear Information System (INIS)

    Genant, H.K.; Resnick, D.

    1988-01-01

    The relative clinical value of magnification compared with conventional radiography for skeletal applications is presented qualitatively. The presentation is based on the authors' experience with over 25,000 cases in which magnification has been used. For most areas in which magnification (optical or geometric) proves useful, subtle abnormalities of clinical importance are present at bone surfaces or at host-lesion interfaces. This is particularly true for arthritis and metabolic and infectious disorders of bone. In additional instances, serial assessment of the progression of disease or its response to therapy is enhanced by magnification. When gross abnormalities are present, as in most instances of trauma and bone dysplasia, the findings are obvious on conventional radiography, and magnification is not necessary. Thus, the magnification techniques appear to provide important diagnostic information, depending upon the anatomic part that is studied and the clinical question that is posed. It is also apparent that the demonstration of subtle skeletal abnormalities to clinical colleagues for educational purposes is greatly enhanced by magnification radiography

  15. Dosimetric comparison of intensity modulated radiation, Proton beam therapy and proton arc therapy for para-aortic lymph node tumor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hoon [Dept. of Radiation Oncology, Konyang University Hospital. Daejeon (Korea, Republic of)

    2014-12-15

    To test feasibility of proton arc therapy (PAT) in the treatment of para-aortic lymph node tumor and compare its dosimetric properties with advanced radiotherapy techniques such as intensity modulated radiation therapy (IMRT) and conventional 3D conformal proton beam therapy (PBT). The treatment plans for para-aortic lymph node tumor were planned for 9 patients treated at our institution using IMRT, PBT, and PAT. Feasibility test and dosimetric evaluation were based on comparisons of dose volume histograms (DVHs) which reveal mean dose, D{sub 30%}, D{sub 60%}, D{sub 90%}, V{sub 30%}, V{sub 60%}, V{sub 90}%, organ equivalent doses (OEDs), normal tissue complication probability (NTCP), homogeneity index (HI) and conformity index (CI). The average doses delivered by PAT to the liver, kidney, small bowel, duodenum, stomach were 7.6%, 3%, 17.3%, 26.7%, and 14.4%, of the prescription dose (PD), respectively, which is higher than the doses delivered by IMRT (0.4%, 7.2%, 14.2%, 15.9%, and 12.8%, respectively) and PBT (4.9%, 0.5%, 14.12%, 16.1% 9.9%, respectively). The average homogeneity index and conformity index of tumor using PAT were 12.1 and 1.21, respectively which were much better than IMRT (21.5 and 1.47, respectively) and comparable to PBT (13.1 and 1.23, respectively). The result shows that both NTCP and OED of PAT are generally lower than IMRT and PBT. This study demonstrates that PAT is better in target conformity and homogeneity than IMRT and PBT but worse than IMRT and PBT for most of dosimetric factor which indicate that PAT is not recommended for the treatment of para-aortic lymph node tumor.

  16. Comparison of dose distribution for proton beams and electrons: advantages and disadvantages; Comparacao de distribuicao de dose para feixes de protons e eletrons: vantagens e desvantagens

    Energy Technology Data Exchange (ETDEWEB)

    Neto, Joao T.M.; Ferreira, Maira B.; Braga, Victor B. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2016-07-01

    This study consists of a simulation of cancer therapy using a beam of protons and electrons. By comparing dose distribution curves for both beams we have showed the advantages and disadvantages of both therapies. The study was performed with Monte Carlo simulations using Geant4 code for a brain tumor, and it was found that the presence of the Bragg peak in proton beam allows a higher dose deposition in tumor and protection of adjacent tissues, while the electron beam has an entry dose in the tissue higher than the proton, yielding to the tissue neighbors of the tumor, unnecessary radiation. Moreover, it was also found significant production of neutrons from the proton beam, showing its main disadvantage. The continuation of this work will add the comparison with clinical beams of photons. (author)

  17. A clinical comparison of image quality and patient exposure reduction in panoramic radiography with heavy metal filtration

    International Nuclear Information System (INIS)

    Kapa, S.F.; Tyndall, D.A.

    1989-01-01

    Laboratory and clinical studies with the use of rare earth intensifying screens and four different forms of heavy metal elements serving as additional beam filtration were performed for panoramic radiography to identify the most efficacious system. Balanced density images were evaluated for contrast indices, resolution, relative dose reduction, and subjective image quality. Clinical studies were performed with a standard calcium tungstate imaging system and the four most promising experimental imaging systems that showed improvement over the standard system. Dosimetric studies were performed with the use of ionization chambers and thermoluminescent dosimetry (TLD) dosimeters. Exposure reductions of 34% to 79%, depending on the anatomic site and the imaging system used, were achieved. Subjective image quality was evaluated and analyzed statistically. This study concluded that the use of a Kodak Lanex regular screen/T-Mat G film with either Lanex screen or yttrium added beam filtration results in reduced patient exposure in panoramic radiography while image quality is maintained or improved

  18. Imaging of sacroiliitis in early seronegative spondylarthropathy. Assessment of abnormalities by MR in comparison with radiography and CT

    DEFF Research Database (Denmark)

    Puhakka, K Bøcker; Jurik, A G; Egund, N

    2003-01-01

    . MATERIAL AND METHODS: The SIJs of 41 patients with early SpA (median duration of inflammatory low back pain of 19 months) were evaluated by MR imaging using STIR, T1, T2, and T1 fat saturated (FS) sequences before and after i.v. Gd contrast medium followed by staging of abnormalities. The findings were...... compared with those obtained by CT and radiography. RESULTS: MR and CT had equal efficacy superior to radiography in staging of erosions and osseous sclerosis. Only MR allowed visualization and grading of active inflammatory changes in the subchondral bone and surrounding ligaments in addition to bone......: semicoronal T1 and both semicoronal and semiaxial STIR. If these images are normal, the examination can be finished; otherwise additional semicoronal T1 FS before and after i.v. contrast has to be performed as well as semiaxial post-contrast T1 FS....

  19. A comparison of digital luminescence radiography and conventional film/screen techniques in the diagnosis of fractures

    International Nuclear Information System (INIS)

    Fink, U.; Schwerdtfeger, J.; Fink, B.K.; Schaetzl, M.; Reiser, M.

    1996-01-01

    The accuracy of digital luminescence radiography was compared with that of conventional film/screen techniques, using animal preparations and clinical examinations. Fine fissures were made in 8 animal bones and these were examined radiologically. The digital examinations were carried out with and without edge enhancement. 208 patients were examined in a similar way. Film quality and assessment of the fractures were evaluated quantitatively. In no instance did either of the digital methods provide inferior quality when compared with conventional films. ROC analysis for evaluation of fractures in patients, using an experienced radiologist, showed no significant difference between the various methods (ROC areas: Conventional 0.947, digital 0.958, digital with edge enhancement 0.943). With a less experienced observer there were significant advantages for both digital methods (ROC areas: 0.851, 0.886, 0.908). Our investigation has proved that fractures which are difficult to see can be reliably demonstrated by digital luminescence radiography. (orig.) [de

  20. Comparison of plain radiography and magnetic resonance in the evaluation of the sacroiliac joint in patients with sacroiliitis

    International Nuclear Information System (INIS)

    Marti-Bonmati, L.; Ybanez, D.; Sarti, M.A.; Belloch, V.

    1996-01-01

    The Ankylosing spondylitis (AS) is an inflammatory disease involving joints and ligaments. plain radiography is an indispensable diagnostic technique in the evaluation of the sacroiliac joint, while the role of magnetic resonance (MR) is yet to be defined. Our purpose is to compare the diagnostic efficacy of plain radiography and MR in the evaluation of sacroiliac joint inflammation. We have carried out a prospective study of 43 individuals, 12 healthy volunteers (control group) and 31 patients with sacroiliitis (18 cases of confirmed AS, 11 of probable AS and 2 of condensing osteitis of the ilium). All the subjects underwent anteroposterior X-ray of pelvis and an MR study that provided two transversal sequences (SE-T2 and SE-PD) and two coronal sequences (SE-T1 and GE-T2). MR was significantly more sensitive than radiography in detecting the loss definition of the joint margins and cortical erosion (P<0.01). It was also more sensitive, although not significantly so, in the detection of subchondral sclerosis, osseous bridges and bone fusion. Erosion revealed by radiography would probably also be detected with MR(p<0.01). Despite the greater sensitivity of MR, plain X-ray should still be considered the technique of choice given its lower cost and greater availability. MR is indicated in patients without radiographic abnormalities in whom there is an evident clinical suspicion of AS. It is yet to be determined whether the greater sensitivity of MR in the detection of abnormality has any prognostic or therapeutic impact in AS patients. 15 refs

  1. Comparison between calculation and measurement of energy deposited by 800 MeV protons

    International Nuclear Information System (INIS)

    Loewe, W.E.

    1980-01-01

    The High Energy Transport Code, HETC, was obtained from the Radiation Shielding Information Center (RSIC) at Oak Ridge National Laboratory and altered as necessary to run on a CDC 7600 using the LTSS software in use at LLNL. HETC was then used to obtain calculated estimates of energy deposited, for comparison with a series of benchmark experiments done by LLNL. These experiments used proton beams of various energies incident on well-defined composite targets in good geometry. In this report, two aspects of the comparison between calculated and experimental energy depositions from an 800 MeV proton beam are discussed. Both aspects involve the fact that workers at SAI had previously used their version of HETC to calculate this experiment and reported their comparison with the measured data. The first aspect addressed is that their calculated data and LLNL calculations do not agree, suggesting an error in the conversion process from the RSIC code. The second aspect is not independent of the first, but is of sufficient importance to merit separate emphasis. It is that the SAI calculations agree well with experiments at the detector plate located some distance from the shower plate, whereas the LLNL calculations show a clearcut discrepancy there in comparison with the experiment. A contract was let in January 1980 by LLNL with SAI in order to obtain full details on the two cited aspects of the comparison between calculated and experimental energy depositions from an 800 MeV proton beam. The ensuing discussion is based on the final report of that contracted work

  2. Comparison of radiography and ultrasonography in the detection of lung and liver cysts in cattle and buffaloes

    Directory of Open Access Journals (Sweden)

    Ashwani Kumar

    2016-10-01

    Full Text Available Aim: Echinococcosis is the major cause of lung and liver cysts in ruminants. This study compared usefulness of radiography and ultrasonography (USG in the detection of lung and/or liver cysts in sick bovine animals. The study also worked out cooccurrence of lung and liver cysts, and whether these cysts were primary cause of sickness or not. Materials and Methods: This study was conducted on 45 sick bovine (37 buffaloes and 8 cattle suffering from lung and liver cysts. A complete history of illness and clinical examination was carried out. Lateral radiographs of chest and reticular region were taken. In radiographically positive or suspected cases of cysts, USG of the lung and liver region was done. Depending on the location of cyst and clinical manifestations of the animal, the cysts were categorized as primary or secondary causes of sickness. Results: Using either imaging technique, it was observed that 46.7% of the animals had both lung and liver cysts, whereas 33.3% had only lung and 20% had only liver cyst. Cysts were identified as primary cause of sickness in 31.1% animals only. For diagnosing lung cysts, radiography (71.1% and USG (62.2% had similar diagnostic utility. However, for detecting liver cysts, USG was the only imaging tool. Conclusion: The lung and liver cysts, depending on their number and size may be a primary cause of sickness in bovine. Radiography and USG are recommended, in combination, as screening tools to rule out echinococcosis.

  3. Comparison of therapeutic dosimetric data from passively scattered proton and photon craniospinal irradiations for medulloblastoma

    Directory of Open Access Journals (Sweden)

    Howell Rebecca M

    2012-07-01

    Full Text Available Abstract Background For many decades, the standard of care radiotherapy regimen for medulloblastoma has been photon (megavoltage x-rays craniospinal irradiation (CSI. The late effects associated with CSI are well-documented in the literature and are in-part attributed to unwanted dose to healthy tissue. Recently, there is growing interest in using proton therapy for CSI in pediatric and adolescent patients to reduce this undesirable dose. Previous comparisons of dose to target and non-target organs from conventional photon CSI and passively scattered proton CSI have been limited to small populations (n ≤ 3 and have not considered the use of age-dependent target volumes in proton CSI. Methods Standard of care treatment plans were developed for both photon and proton CSI for 18 patients. This cohort included both male and female medulloblastoma patients whose ages, heights, and weights spanned a clinically relevant and representative spectrum (age 2–16, BMI 16.4–37.9 kg/m2. Differences in plans were evaluated using Wilcoxon signed rank tests for various dosimetric parameters for the target volumes and normal tissue. Results Proton CSI improved normal tissue sparing while also providing more homogeneous target coverage than photon CSI for patients across a wide age and BMI spectrum. Of the 24 parameters (V5, V10, V15, and V20 in the esophagus, heart, liver, thyroid, kidneys, and lungs Wilcoxon signed rank test results indicated 20 were significantly higher for photon CSI compared to proton CSI (p ≤ 0.05 . Specifically, V15 and V20 in all six organs and V5, V10 in the esophagus, heart, liver, and thyroid were significantly higher with photon CSI. Conclusions Our patient cohort is the largest, to date, in which CSI with proton and photon therapies have been compared. This work adds to the body of literature that proton CSI reduces dose to normal tissue compared to photon CSI for pediatric patients who are at substantial risk for

  4. Proton Radiotherapy for High-Risk Pediatric Neuroblastoma: Early Outcomes and Dose Comparison

    Energy Technology Data Exchange (ETDEWEB)

    Hattangadi, Jona A. [Harvard Radiation Oncology Program, Boston, MA (United States); Rombi, Barbara [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Provincial Agency for Proton Therapy, Trento (Italy); Yock, Torunn I.; Broussard, George [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Friedmann, Alison M.; Huang, Mary [Department of Pediatric Hematology-Oncology, Massachusetts General Hospital, Boston, MA (United States); Chen, Yen-Lin E.; Lu, Hsiao-Ming; Kooy, Hanne [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); MacDonald, Shannon M., E-mail: smacdonald@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States)

    2012-07-01

    for high-risk neuroblastoma, although distant failures continu to occur. Dosimetric comparisons demonstrate the advantage of proton RT compared with IMRT in this setting, allowing more conformal treatment and better normal tissue sparing.

  5. Comparison of therapeutic dosimetric data from passively scattered proton and photon craniospinal irradiations for medulloblastoma

    International Nuclear Information System (INIS)

    Howell, Rebecca M; Giebeler, Annelise; Koontz-Raisig, Wendi; Mahajan, Anita; Etzel, Carol J; D’Amelio, Anthony M Jr; Homann, Kenneth L

    2012-01-01

    For many decades, the standard of care radiotherapy regimen for medulloblastoma has been photon (megavoltage x-rays) craniospinal irradiation (CSI). The late effects associated with CSI are well-documented in the literature and are in-part attributed to unwanted dose to healthy tissue. Recently, there is growing interest in using proton therapy for CSI in pediatric and adolescent patients to reduce this undesirable dose. Previous comparisons of dose to target and non-target organs from conventional photon CSI and passively scattered proton CSI have been limited to small populations (n ≤ 3) and have not considered the use of age-dependent target volumes in proton CSI. Standard of care treatment plans were developed for both photon and proton CSI for 18 patients. This cohort included both male and female medulloblastoma patients whose ages, heights, and weights spanned a clinically relevant and representative spectrum (age 2–16, BMI 16.4–37.9 kg/m2). Differences in plans were evaluated using Wilcoxon signed rank tests for various dosimetric parameters for the target volumes and normal tissue. Proton CSI improved normal tissue sparing while also providing more homogeneous target coverage than photon CSI for patients across a wide age and BMI spectrum. Of the 24 parameters (V 5 , V 10 , V 15 , and V 20 in the esophagus, heart, liver, thyroid, kidneys, and lungs) Wilcoxon signed rank test results indicated 20 were significantly higher for photon CSI compared to proton CSI (p ≤ 0.05) . Specifically, V 15 and V 20 in all six organs and V 5 , V 10 in the esophagus, heart, liver, and thyroid were significantly higher with photon CSI. Our patient cohort is the largest, to date, in which CSI with proton and photon therapies have been compared. This work adds to the body of literature that proton CSI reduces dose to normal tissue compared to photon CSI for pediatric patients who are at substantial risk for developing radiogenic late effects. Although the present study

  6. Digital radiography

    International Nuclear Information System (INIS)

    Coulomb, M.; Dal Soglio, S.; Pittet-Barbier, L.; Ranchoup, Y.; Thony, F.; Ferretti, G.; Robert, F.

    1992-01-01

    Digital projection radiography may replace conventional radiography some day, provided it can meet several requirements: equal or better diagnostic effectiveness of the screen-film systems; reasonable image cost; real improvement in the productivity of the Departments of Imaging. All digital radiographic systems include an X-ray source, an image acquisition and formatting sub-system, a display and manipulation sub-system, and archiving subsystem and a laser editing system, preferably shared by other sources of digital images. Three digitization processes are available: digitization of the radiographic film, digital fluorography and phospholuminescent detectors with memory. The advantages of digital fluoroscopy are appealing: real-time image acquisition, suppression of cassettes; but its disadvantages are far from negligible: it cannot be applied to bedside radiography, the field of examination is limited, and the wide-field spatial resolution is poor. Phospholuminescent detectors with memory have great advantages: they can be used for bedside radiographs and on all the common radiographic systems; spatial resolution is satisfactory; its current disadvantages are considerable. These two systems, have common properties making up the entire philosophy of digital radiology and specific features that must guide our choice according to the application. Digital fluorography is best applied in pediatric radiology. However, evaluation works have showed that it was applicable with sufficient quality to many indications of general radiology in which a fluoroscopic control and fast acquisition of the images are essential; the time gained on the examination may be considerable, as well as the savings on film. Detectors with memory are required for bedside radiographs, in osteoarticular and thoracic radiology, in all cases of traumatic emergency and in the resuscitation and intensive care departments

  7. In situ observation of self-propagating high temperature syntheses of Ta5Si3, Ti5Si3 and TiB2 by proton and X-ray radiography

    Science.gov (United States)

    Bernert, T.; Winkler, B.; Haussühl, E.; Trouw, F.; Vogel, S. C.; Hurd, A. J.; Smilowitz, L.; Henson, B. F.; Merrill, F. E.; Morris, C. L.; Mariam, F. G.; Saunders, A.; Juarez-Arellano, E. A.

    2013-08-01

    Self-propagating high temperature reactions of tantalum and titanium with silicon and titanium with boron were studied using proton and X-ray radiography, small-angle neutron scattering, neutron time-of-flight, X-ray and neutron diffraction, dilatometry and video recording. We show that radiography allows the observation of the propagation of the flame front in all investigated systems and the determination of the widths of the burning zones. X-ray and neutron diffraction showed that the reaction products consisted of ≈90 wt% of the main phase and one or two secondary phases. For the reaction 5Ti + 3Si → Ti5Si3 flame front velocities of 7.1(3)-34.2(4) mm/s were determined depending on the concentration of a retardant added to the starting material, the geometry and the green density of the samples. The flame front width was determined to be 1.17(4)-1.82(8) mm and depends exponentially on the flame front velocity. Similarly, for the reaction Ti + 2B → TiB2 flame front velocities of 15(2)-26.6(4) mm/s were determined, while for a 5Ta + 3Si → Ta5Si3 reaction the flame front velocity was 7.05(4) mm/s. The micro structure of the product phase Ta5Si3 shows no texture. From SANS measurements the dependence of the specific surface of the product phase on the particle sizes of the starting materials was studied.

  8. Pencil beam scanning proton therapy vs rotational arc radiation therapy: A treatment planning comparison for postoperative oropharyngeal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Apinorasethkul, Ontida, E-mail: Ontida.a@gmail.com; Kirk, Maura; Teo, Kevin; Swisher-McClure, Samuel; Lukens, John N.; Lin, Alexander

    2017-04-01

    Patients diagnosed with head and neck cancer are traditionally treated with photon radiotherapy. Proton therapy is currently being used clinically and may potentially reduce treatment-related toxicities by minimizing the dose to normal organs in the treatment of postoperative oropharyngeal cancer. The finite range of protons has the potential to significantly reduce normal tissue toxicity compared to photon radiotherapy. Seven patients were planned with both proton and photon modalities. The planning goal for both modalities was achieving the prescribed dose to 95% of the planning target volume (PTV). Dose-volume histograms were compared in which all cases met the target coverage goals. Mean doses were significantly lower in the proton plans for the oral cavity (1771 cGy photon vs 293 cGy proton, p < 0.001), contralateral parotid (1796 cGy photon vs 1358 proton, p < 0.001), and the contralateral submandibular gland (3608 cGy photon vs 3251 cGy proton, p = 0.03). Average total integral dose was 9.1% lower in proton plans. The significant dosimetric sparing seen with proton therapy may lead to reduced side effects such as pain, weight loss, taste changes, and dry mouth. Prospective comparisons of protons vs photons for disease control, toxicity, and patient-reported outcomes are therefore warranted and currently being pursued.

  9. Radiography shielding

    Energy Technology Data Exchange (ETDEWEB)

    Redmayne, I.

    1985-11-27

    Apparatus for the inspection of a pipe weld by radiography comprises a radiation source contained in a housing having a first collimator for defining the exit beam and a second collimator mountable on the pipe in the region of the weld to define with the first collimator a predetermined volume enclosing the radiation beam passing through the second collimator when the housing is in a predetermined position relative to the second collimator. The arrangement is such that if the housing is slightly displaced from the predetermined position the radiation beam still falls within the predetermined volume.

  10. Radiography shielding

    International Nuclear Information System (INIS)

    Redmayne, I.

    1985-01-01

    Apparatus for the inspection of a pipe weld by radiography comprises a radiation source contained in a housing having a first collimator for defining the exit beam and a second collimator mountable on the pipe in the region of the weld to define with the first collimator a predetermined volume enclosing the radiation beam passing through the second collimator when the housing is in a predetermined position relative to the second collimator. The arrangement is such that if the housing is slightly displaced from the predetermined position the radiation beam still falls within the predetermined volume. (author)

  11. Digital Radiography

    Science.gov (United States)

    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.

  12. Digital radiography

    International Nuclear Information System (INIS)

    Elander, S.; Hellesnes, J.; Reitan, J.B.

    1992-01-01

    The technology of radiography is developing rapidly, both regarding imaging technology and data hardware, and software technology. More and more advanced systems are marketed by the radiological companies. The wide product range makes it difficult to get an overview over principles and components. By closer inspection, however, the number of basic components and technologies is limited. Moreover, the components seem rather well known from other technologies, due to the long times of development in radiology. This report gives a survey of some new principles and components in the video chain. As components may deteriorate or age fast by irradiation, the radiation levels in the chain are evaluated. 13 refs

  13. Radiography apparatus

    International Nuclear Information System (INIS)

    Sashin, D.; Sternglass, E.J.

    1982-01-01

    The apparatus of the present invention provides radiography apparatus wherein the use of a flat, generally rectangular beam or a fan-shaped beam of radiation in combination with a collimator, scintillator and device for optically coupling a self-scanning array of photodiodes to the scintillator means will permit production of images or image data with high contrast sensitivity and detail. It is contemplated that the self-scanning array of photodiodes may contain from about 60 to 2048, and preferably about 256 to 2048, individual photodiode elements per inch of object width, thereby permitting maximum data collection to produce a complete image or complete collection of image data

  14. Comparison of coaxial higher order mode couplers for the CERN Superconducting Proton Linac study

    CERN Document Server

    AUTHOR|(CDS)2085329; Gerigk, Frank; Van Rienen, Ursula

    2017-01-01

    Higher order modes (HOMs) may affect beam stability and refrigeration requirements of superconducting proton linacs such as the Superconducting Proton Linac, which is studied at CERN. Under certain conditions beam-induced HOMs can accumulate sufficient energy to destabilize the beam or quench the superconducting cavities. In order to limit these effects, CERN considers the use of coaxial HOM couplers on the cutoff tubes of the 5-cell superconducting cavities. These couplers consist of resonant antennas shaped as loops or probes, which are designed to couple to potentially dangerous modes while sufficiently rejecting the fundamental mode. In this paper, the design process is presented and a comparison is made between various designs for the high-beta SPL cavities, which operate at 704.4 MHz. The rf and thermal behavior as well as mechanical aspects are discussed. In order to verify the designs, a rapid prototype for the favored coupler was fabricated and characterized on a low-power test-stand.

  15. Assessment of survey radiography and comparison with x-ray computed tomography for detection of hyperfunctioning adrenocortical tumors in dogs

    International Nuclear Information System (INIS)

    Voorhout, G.; Stolp, R.; Rijnberk, A.; Waes, P.F.G.M. van

    1990-01-01

    Results of abdominal survey radiography and x-ray computed tomography (CT) were compared in 13 dogs with hyperadrenocorticism histologically attributed to adrenocortical tumors. X-ray computed tomography enabled accurate localization of the tumor in all 13 dogs. Apart from 2 poorly demarcated irregular-shaped and mineralized carcinomas, there were no differences between adenoma (n = 3) and carcinoma (n = 10) on CT images. In 1 dog, invasion of the caudal vena cava by the tumor was suggested on CT images and was confirmed during surgery. Suspicion of adhesions between tumors of the right adrenal gland and the caudal vena cava on the basis of CT images was confirmed during surgery in only 2 of 6 dogs. Survey radiography allowed accurate localization of the tumor in 7 dogs (4 on the right side and 3 on the left). In 6 of these dogs, the tumor was visible as a well-demarcated soft tissue mass and, in the other dog, as a poorly demarcated mineralized mass. The smallest tumor visualized on survey radiographs had a diameter of 20 mm on CT images. Six tumors with diameter less than or equal to 20 mm were not visualized on survey radiographs. In 1 of these dogs, a mineralized nodule was found in the left adrenal region, without evidence of a mass. In a considerable number of cases, survey radiography can provide presurgical localization of adrenocortical tumors in dogs with hyperadrenocorticism; CT is redundant in these instances. In the absence of positive radiographic findings, CT is valuable for localization of adrenocortical tumors

  16. Skeletal imaging following reconstruction of the posterior cruciate ligament: in vivo comparison of fluoroscopy, radiography, and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Osti, Michael; Benedetto, Karl Peter [Academic Hospital Feldkirch, Department for Trauma Surgery and Sports Traumatology, Feldkirch (Austria); Krawinkel, Alessa [Academic Hospital Feldkirch, Department for Radiology, Feldkirch (Austria)

    2014-12-15

    Intra- and postoperative validation of anatomic footprint replication in posterior cruciate ligament (PCL) reconstruction can be conducted using fluoroscopy, radiography, or computed tomography (CT) scans. However, effectiveness and exposure to radiation of these imaging modalities are unknown. The objective of this study was to evaluate the comparative effectiveness of fluoroscopy, radiography, and CT in detecting femoral and tibial tunnel positions following an all-inside reconstruction of the PCL ligament in vivo. The study design was a retrospective case series. Intraoperative fluoroscopic images, postoperative radiographs, and CT scans were obtained in 50 consecutive patients following single-bundle PCL reconstruction. The centers of the tibial and femoral tunnel apertures were identified and correlated to measurement grid systems. The results of fluoroscopic, radiographic, and CT measurements were compared to each other and accumulated radiation dosages were calculated. Comparing the imaging groups, no statistically significant difference could be detected for the reference of the femoral tunnel to the intercondylar depth and height, for the reference of the tibial tunnel to the mediolateral diameter of the tibial plateau and for the superoinferior distance of the tibial tunnel entry to the tibial plateau and to the former physis line. Effective doses resulting from fluoroscopic, radiographic, and CT exposure averaged 2.9 mSv, standard deviation (±SD) 4.1 mSv, to 1.3 ± 0.8 mSv and to 3.6 ± 1.0 mSv, respectively. Fluoroscopy, radiography, and CT yield approximately equal effectiveness in detecting parameters used for quality validation intra- and postoperatively. An accumulating exposure to radiation must be considered. (orig.)

  17. Image quality in digital radiography

    International Nuclear Information System (INIS)

    Kuhn, H.

    1986-01-01

    The contribution deals with the potentials of digital radiography and critically evaluates the advantages of drawbacks of the image intensifier-tv-digital system; digitalisation of the X-ray film and scanning of luminescent storage foils. The evaluation is done in comparison with the image quality of the traditional, large-size X-ray picture. (orig.) [de

  18. Comparison of patient specific dose metrics between chest radiography, tomosynthesis, and CT for adult patients of wide ranging body habitus

    International Nuclear Information System (INIS)

    Zhang, Yakun; Li, Xiang; Segars, W. Paul; Samei, Ehsan

    2014-01-01

    Purpose: Given the radiation concerns inherent to the x-ray modalities, accurately estimating the radiation doses that patients receive during different imaging modalities is crucial. This study estimated organ doses, effective doses, and risk indices for the three clinical chest x-ray imaging techniques (chest radiography, tomosynthesis, and CT) using 59 anatomically variable voxelized phantoms and Monte Carlo simulation methods. Methods: A total of 59 computational anthropomorphic male and female extended cardiac-torso (XCAT) adult phantoms were used in this study. Organ doses and effective doses were estimated for a clinical radiography system with the capability of conducting chest radiography and tomosynthesis (Definium 8000, VolumeRAD, GE Healthcare) and a clinical CT system (LightSpeed VCT, GE Healthcare). A Monte Carlo dose simulation program (PENELOPE, version 2006, Universitat de Barcelona, Spain) was used to mimic these two clinical systems. The Duke University (Durham, NC) technique charts were used to determine the clinical techniques for the radiographic modalities. An exponential relationship between CTDI vol and patient diameter was used to determine the absolute dose values for CT. The simulations of the two clinical systems compute organ and tissue doses, which were then used to calculate effective dose and risk index. The calculation of the two dose metrics used the tissue weighting factors from ICRP Publication 103 and BEIR VII report. Results: The average effective dose of the chest posteroanterior examination was found to be 0.04 mSv, which was 1.3% that of the chest CT examination. The average effective dose of the chest tomosynthesis examination was found to be about ten times that of the chest posteroanterior examination and about 12% that of the chest CT examination. With increasing patient average chest diameter, both the effective dose and risk index for CT increased considerably in an exponential fashion, while these two dose metrics

  19. Comparison of patient specific dose metrics between chest radiography, tomosynthesis, and CT for adult patients of wide ranging body habitus

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yakun [Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Li, Xiang [Medical Physics Graduate Program, Department of Physics, Cleveland State University, Cleveland, Ohio 44115 (United States); Segars, W. Paul [Medical Physics Graduate Program, Carl E. Ravin Advanced Imaging Laboratories, and Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Samei, Ehsan, E-mail: samei@duke.edu [Medical Physics Graduate Program, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Departments of Physics, Biomedical Engineering, and Electrical and Computer Engineering, Duke University Medical Center, Durham, North Carolina 27705 (United States)

    2014-02-15

    Purpose: Given the radiation concerns inherent to the x-ray modalities, accurately estimating the radiation doses that patients receive during different imaging modalities is crucial. This study estimated organ doses, effective doses, and risk indices for the three clinical chest x-ray imaging techniques (chest radiography, tomosynthesis, and CT) using 59 anatomically variable voxelized phantoms and Monte Carlo simulation methods. Methods: A total of 59 computational anthropomorphic male and female extended cardiac-torso (XCAT) adult phantoms were used in this study. Organ doses and effective doses were estimated for a clinical radiography system with the capability of conducting chest radiography and tomosynthesis (Definium 8000, VolumeRAD, GE Healthcare) and a clinical CT system (LightSpeed VCT, GE Healthcare). A Monte Carlo dose simulation program (PENELOPE, version 2006, Universitat de Barcelona, Spain) was used to mimic these two clinical systems. The Duke University (Durham, NC) technique charts were used to determine the clinical techniques for the radiographic modalities. An exponential relationship between CTDI{sub vol} and patient diameter was used to determine the absolute dose values for CT. The simulations of the two clinical systems compute organ and tissue doses, which were then used to calculate effective dose and risk index. The calculation of the two dose metrics used the tissue weighting factors from ICRP Publication 103 and BEIR VII report. Results: The average effective dose of the chest posteroanterior examination was found to be 0.04 mSv, which was 1.3% that of the chest CT examination. The average effective dose of the chest tomosynthesis examination was found to be about ten times that of the chest posteroanterior examination and about 12% that of the chest CT examination. With increasing patient average chest diameter, both the effective dose and risk index for CT increased considerably in an exponential fashion, while these two dose

  20. neutron radiography

    International Nuclear Information System (INIS)

    Barton, J.P.

    1993-01-01

    Neutron radiography (or radiology) is a diverse filed that uses neutrons of various energies, subthermal, thermal, epithermal or fast in either steady state or pulsed mode to examine objects for industrial, medical, or other purposes, both microscopic and macroscopic. The applications include engineering design, biological studies, nondestructive inspection and materials evaluation. In the past decade, over 100 different centers in some 30 countries have published reports of pioneering activities using reactors, accelerators and isotopic neutron sources. While film transparency and electronic video are most common imaging methods for static or in motion objects respectively, there are other important data gathering techniques, including track etch, digital gauging and computed tomography. A survey of the world-wide progress shows the field to be gaining steadily in its diversity, its sophistication and its importance. (author)

  1. Electron radiography

    Science.gov (United States)

    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.

  2. Filmless Radiography

    Science.gov (United States)

    1997-01-01

    Technology initially prototyped under a Small Business Innovation Research contract between Quantex Corporation and Langley Research Center was licensed to Liberty Technology and incorporated into RADView, a new filmless radiography technology. The NASA-sponsored work involved the investigation of Electron Trapping, which led to a solid-state film that uses a special class of photoluminescent materials to capture radiographic images. RadView is a total imaging solution for the conversion of radiographic film records to digital format and digital acquisitions of radiographs. With the RADView technology, there is a reduction of exposure times and errors; film waste is eliminated; and the efficiency of data management and precise image analysis is boosted. The solid-state film can be exposed, read, erased, and re- exposed indefinitely until mechanical replacement is required. Digital images can be stored to optical media for up to 100 years and beyond without information loss.

  3. A Comparison of Plain Radiography with Computer Tomography in Determining Coronal and Sagittal Alignments following Total Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Solayar GN

    2017-07-01

    Full Text Available INTRODUCTION: Optimal coronal and sagittal component positioning is important in achieving a successful outcome following total knee arthroplasty (TKA. Modalities to determine post-operative alignment include plain radiography and computer tomography (CT imaging. This study aims to determine the accuracy and reliability of plain radiographs in measuring coronal and sagittal alignment following TKA. MATERIALS AND METHODS: A prospective, consecutive study of 58 patients undergoing TKA was performed comparing alignment data from plain radiographs and CT imaging. Hip- knee-angle (HKA, sagittal femoral angle (SFA and sagittal tibial angle (STA measurements were taken by two observers from plain radiographs and compared with CT alignment. Intra- and inter-observer correlation was calculated for each measurement. RESULTS: Intra-observer correlation was excellent for HKA (r>0.89 with a mean difference of 0.95 and STA (r>0.8 compared to SFA (r=0.5. When comparing modalities (radiographs vs CT, HKA estimations for both observers showed the least maximum and mean differences while SFA observations were the least accurate. CONCLUSION: Radiographic estimation of HKA showed excellent intra- and inter-observer correlation and corresponds well with CT imaging. However, radiographic estimation of sagittal plane alignment was less reliably measured and correlated less with CT imaging. Plain radiography was found to be inferior to CT for estimation of biplanar prosthetic alignment following TKA.

  4. Comparison of image quality among three x-ray systems for chest radiography: first step in optimisation

    International Nuclear Information System (INIS)

    Nocetti, D.; Ubeda, C.; Calcagno, S.; Acevedo, J.; Pardo, D.

    2015-01-01

    The aim of this study was to compare the performance of three digital X-ray systems [one flat-panel (DR) and two computed radiography (CR)] for chest radiography in terms of the entrance surface air kerma (ESAK) delivered to a polymethyl methacrylate phantom of 20 cm (equivalent to an adult patient) and image quality through of numerical evaluations using a test object (TO). The tube charge applied was ranged from 0.6 to 32 mAs, to a fixed tension of 125 kVp. The DR system presented the highest mean values of ESAK (615.9 μGy) along with the highest signal-to-noise ratio values, whereas CR systems showed a better high-contrast spatial resolution. Differences were statistically significant in both cases regarding the tube charge used. Thus, this parameter should be mainly considered to optimise the radiological protection through exposure settings selected. This survey represents the first effort to achieve optimisation in digital radiology for Chile. (authors)

  5. Small lung cancers: improved detection by use of bone suppression imaging--comparison with dual-energy subtraction chest radiography.

    Science.gov (United States)

    Li, Feng; Engelmann, Roger; Pesce, Lorenzo L; Doi, Kunio; Metz, Charles E; Macmahon, Heber

    2011-12-01

    To determine whether use of bone suppression (BS) imaging, used together with a standard radiograph, could improve radiologists' performance for detection of small lung cancers compared with use of standard chest radiographs alone and whether BS imaging would provide accuracy equivalent to that of dual-energy subtraction (DES) radiography. Institutional review board approval was obtained. The requirement for informed consent was waived. The study was HIPAA compliant. Standard and DES chest radiographs of 50 patients with 55 confirmed primary nodular cancers (mean diameter, 20 mm) as well as 30 patients without cancers were included in the observer study. A new BS imaging processing system that can suppress the conspicuity of bones was applied to the standard radiographs to create corresponding BS images. Ten observers, including six experienced radiologists and four radiology residents, indicated their confidence levels regarding the presence or absence of a lung cancer for each lung, first by using a standard image, then a BS image, and finally DES soft-tissue and bone images. Receiver operating characteristic (ROC) analysis was used to evaluate observer performance. The average area under the ROC curve (AUC) for all observers was significantly improved from 0.807 to 0.867 with BS imaging and to 0.916 with DES (both P chest radiographs. Further improvements can be achieved by use of DES radiography but with the requirement for special equipment and a potential small increase in radiation dose. © RSNA, 2011.

  6. Comparison of digital radiography and apex locator with the conventional method in root length determination of primary teeth

    Directory of Open Access Journals (Sweden)

    I E Neena

    2011-01-01

    Full Text Available Aim: The purpose of this study was to compare the Working length in primary teeth endodontics using intra oral digital radiovisiography and apex locator with conventional method for accuracy. Materials and Methods: This in vivo study was conducted on 30 primary teeth which were indicated for pulpectomy in the patients of the age group of 5-11 years All experimental teeth had adequate remaining tooth structure for rubber dam isolation and radiographicaly visible canals. Endodontic treatment was required due to irreversible pulpitis or pulp necrosis. A standardized intraoral periapical radiograph of the tooth was taken using conventional method by paralleling technique. The distance between the source and the tooth, tooth and the films were standardized using X-ray positioning device. During the pulpectomy procedure, the working length was determined by digital radiograph and apex locator. The measurements were then compared with the conventional method of root canal measurement technique for accuracy Result: From the results obtained we can conclude that Working length determined in primary molars using digital radiography and Apex locator did not show any significant difference in the mean working length measurements when compared with the conventional radiographic method. Conclusions: Apex locator is comparable to conventional radiograph in determining the working length without radiation in the primary teeth. Intraoral digital radiography is the safest method in determining the working length with significant reduction in radiation exposure.Hence, both the techniques can be safely used as alternatives to conventional radiographic methods in determining working length in primary teeth.

  7. Challenging the Standard Model: High-Precision Comparisons of the Fundamental Properties of Protons and Antiprotons

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    The Baryon Antibaryon Symmetry Experiment (BASE-CERN) at CERN’s antiproton decelerator facility is aiming at high-precision comparisons of the fundamental properties of protons and antiprotons, such as charge-to-mass ratios, magnetic moments and lifetimes. Such experiments provide sensitive tests of the fundamental charge-parity-time invariance in the baryon sector. BASE was approved in 2013 and has measured since then, utilizing single-particle multi-Penning-trap techniques, the antiproton-to-proton charge-to-mass ratio with a fractional precision of 69 p.p.t. [1], as well as the antiproton magnetic moment with fractional precisions of 0.8 p.p.m. and 1.5 p.p.b., respectively [2]. At our matter companion experiment BASE-Mainz, we have performed proton magnetic moment measurements with fractional uncertainties of 3.3 p.p.b. [3] and 0.3 p.p.b. [4]. By combining the data of both experiments we provide a baryon-magnetic-moment based CPT test gpbar/gp = 1.000 000 000 2(15), which improves the uncertainty of p...

  8. Comparison of plain radiography, conventional tomography, and computed tomography in detecting intrathoracic lymph node metastases from lung carcinoma

    International Nuclear Information System (INIS)

    Osborne, D.R.; Korobkin, M.; Ravin, C.E.

    1982-01-01

    Forty-two patients with T2 bronchogenic carcinoma were evaluated with plain radiography, conventional 55 0 oblique hilar and anteroposterior mediastinal tomography, and computed tomography (CT) to compare their accuracy in assessing mediastinal and hilar nodal metastases. Definitive staging was achieved by thoracotomy and histopathological evaluation of resected specimens. All modalities demonstrated about the same accuracy, however, in the 25 patients with hilar and/or mediastinal lymphadenopathy, CT of the mediastinum was more sensitive but not more specific than the other two and conventional tomography was no more accurate than CT for hilar evaluation. Overall, no technicue was accurate enough for routine staging; their value may lie in directing biopsy or in treatment planning in patients with inoperable disease

  9. The comparison of mandibular radiomorphometric indices in panoramic radiography between patients with chronic periodontitis and healthy individuals.

    Science.gov (United States)

    Moeintaghavi, Amir; Hosseinizarch, Hossein; Tabassi, Sara Mohammadzadeh

    2014-07-01

    Osteoporosis and periodontitis are two separate diseases with different origins and manifestations. It is believed that these diseases linked together, because they both lead to bone damage, some risk factors are similar, they both have the highest prevalence in middle-aged and older women. Some studies showed that the use of panoramic radiography and special indices could be reliable tools for osteoporosis screening. This study was performed to evaluate the relationship between periodontal disease and jaw osteoporotic indices. Eighty-two patients with chronic periodontitis and 80 healthy individuals were selected, they had been referred to a private oral and maxillofacial radiology clinic to take a panoramic radiograph. Then panoramic indicators; including the mandibular cortical index (MCI), mental index (MI), and panoramic mandible index (PMI) in both groups were measured, recorded and analyzed. The mean age of investigated individuals was 39/8 ± 9/33. 58.6% of participants were females and 41.4% were males. MI and PMI levels in the periodontal group were more than the periodontally healthy group, but the differences between the two groups was not statistically significant (p = 0.808 and p = 0.102 respectively). The MCI level was significantly different between two groups (p = 0.028). The results of this study showed that there is significant relationship between MCI in panoramic radiography and chronic periodontitis. It is suggested to perform more studies to confrm if this index could be used for screening and indicating of bone status in high risk individuals. This study did not show a strong evidence of a relationship between osteoporosis and periodontitis. Since panoramic radiographs are routinely used for screening in dental practice, any association between radiomorphometric indices of mandible in periodontitis patients might be useful in prediction of osteoporosis in patients referring to dental clinics.

  10. Comparison of short-lived medical isotopes activation by laser thin target induced protons and conventional cyclotron proton beams

    Science.gov (United States)

    Murray, Joseph; Dudnikova, Galina; Liu, Tung-Chang; Papadopoulos, Dennis; Sagdeev, Roald; Su, J. J.; UMD MicroPET Team

    2014-10-01

    Production diagnostic or therapeutic nuclear medicines are either by nuclear reactors or by ion accelerators. In general, diagnostic nuclear radioisotopes have a very short half-life varying from tens of minutes for PET tracers and few hours for SPECT tracers. Thus supplies of PET and SPECT radiotracers are limited by regional production facilities. For example 18F-fluorodeoxyglucose (FDG) is the most desired tracer for positron emission tomography because its 110 minutes half-life is sufficient long for transport from production facilities to nearby users. From nuclear activation to completing image taking must be done within 4 hours. Decentralized production of diagnostic radioisotopes will be idea to make high specific activity radiotracers available to researches and clinicians. 11 C, 13 N, 15 O and 18 F can be produced in the energy range from 10-20 MeV by protons. Protons of energies up to tens of MeV generated by intense laser interacting with hydrogen containing targets have been demonstrated by many groups in the past decade. We use 2D PIC code for proton acceleration, Geant4 Monte Carlo code for nuclei activation to compare the yields and specific activities of short-lived isotopes produced by cyclotron proton beams and laser driven protons.

  11. Industrial radiographies

    CERN Multimedia

    2005-01-01

    The Radiation Protection group wishes to remind CERN staff responsible for contractors performing X-ray inspections on the CERN sites that the firms must apply the legislation in force in their country of origin, in particular with regard to the prevention of risks relating to ionizing radiation. Industrial radiography firms called on to work on the CERN sites must also comply with the rules laid down in CERN's Radiation Safety Manual and be registered in the relevant CERN database. Since CERN is responsible for safety on its own site, a number of additional rules have been laid down for this kind of work, as set out in Radiation Protection Procedure PRP30 https://edms.cern.ch/file/346848/LAST_RELEASED/PRP30.pdf The CERN Staff Member responsible for the contract shall register the company and issue notification that an X-ray inspection is to be performed via the web interface at the following address: http://cern.ch/rp-radio

  12. Neutron radiography

    International Nuclear Information System (INIS)

    Hiraoka, Eiichi

    1988-01-01

    The thermal neutron absorption coefficient is essentially different from the X-ray absorption coefficient. Each substance has a characteristic absorption coefficient regardless of its density. Neutron deams have the following features: (1) neutrons are not transmitted efficiently by low molecular weight substances, (2) they are transmitted efficiently by heavy metals, and (3) the transmittance differs among isotopes. Thus, neutron beams are suitable for cheking for foreign matters in heavy metals and testing of composites consisting of both heavy and light materials. A neutron source generates fast neutrons, which should be converted into thermal neutrons by reducing their energy. Major neutron souces include nuclear reactors, radioisotopes and particle accelerators. Photographic films and television systems are mainly used to observe neutron transmission images. Computers are employed for image processing, computerized tomography and three-dimensional analysis. The major applications of neutron radiography include inspection of neclear fuel; evaluation of material for airplane; observation of fuel in the engine and oil in the hydraulic systems in airplanes; testing of composite materials; etc. (Nogami, K.)

  13. Comparison of radiation dose, workflow, patient comfort and financial break-even of standard digital radiography and a novel biplanar low-dose X-ray system for upright full-length lower limb and whole spine radiography

    International Nuclear Information System (INIS)

    Dietrich, Tobias J.; Pfirrmann, Christian W.A.; Pankalla, Katja; Buck, Florian M.; Schwab, Alexander

    2013-01-01

    To compare the radiation dose, workflow, patient comfort, and financial break-even of a standard digital radiography and a biplanar low-dose X-ray system. A standard digital radiography system (Ysio, Siemens Healthcare, Erlangen, Germany) was compared with a biplanar X-ray unit (EOS, EOS imaging, Paris, France) consisting of two X-ray tubes and slot-scanning detectors, arranged at an angle of 90 allowing simultaneous vertical biplanar linear scanning in the upright patient position. We compared data of standing full-length lower limb radiographs and whole spine radiographs of both X-ray systems. Dose-area product was significantly lower for radiographs of the biplanar X-ray system than for the standard digital radiography system (e.g. whole spine radiographs; standard digital radiography system: 392.2 ± 231.7 cGy*cm 2 versus biplanar X-ray system: 158.4 ± 103.8 cGy*cm 2 ). The mean examination time was significantly shorter for biplanar radiographs compared with standard digital radiographs (e.g. whole spine radiographs: 449 s vs 248 s). Patients' comfort regarding noise was significantly higher for the standard digital radiography system. The financial break-even point was 2,602 radiographs/year for the standard digital radiography system compared with 4,077 radiographs/year for the biplanar X-ray unit. The biplanar X-ray unit reduces radiation exposure and increases subjective noise exposure to patients. The biplanar X-ray unit demands a higher number of examinations per year for the financial break-even point, despite the lower labour cost per examination due to the shorter examination time. (orig.)

  14. Interobserver agreement and performance score comparison in quality control using a breast phantom: screen-film mammography vs computed radiography

    International Nuclear Information System (INIS)

    Shimamoto, Kazuhiro; Ikeda, Mitsuru; Satake, Hiroko; Ishigaki, Satoko; Sawaki, Akiko; Ishigaki, Takeo

    2002-01-01

    Our objective was to evaluate interobserver agreement and to compare the performance score in quality control of screen-film mammography and computed radiography (CR) using a breast phantom. Eleven radiologists interpreted a breast phantom image (CIRS model X) by four viewing methods: (a) original screen-film; (b) soft-copy reading of the digitized film image; (c) hard-copy reading of CR using an imaging plate; and (d) soft-copy reading of CR. For the soft-copy reading, a 17-in. CRT monitor (1024 x 1536 x 8 bits) was used. The phantom image was evaluated using a scoring system outlined in the instruction manual, and observers judged each object using a three-point rating scale: (a) clearly seen; (b) barely seen; and (c) not seen. For statistical analysis, the kappa statistic was employed. For ''mass'' depiction, interobserver agreement using CR was significantly lower than when using screen-film (p<0.05). There was no significant difference in the kappa value for detecting ''microcalcification''; however, the performance score of ''microcalcification'' on CR hard-copy was significantly lower than on the other three viewing methods (p<0.05). Viewing methods (film or CR, soft-copy or hard-copy) could affect how the phantom image is judged. Paying special attention to viewing conditions is recommended for quality control of CR mammograms. (orig.)

  15. Comparison of coaxial higher order mode couplers for the CERN Superconducting Proton Linac study

    Directory of Open Access Journals (Sweden)

    K. Papke

    2017-06-01

    Full Text Available Higher order modes (HOMs may affect beam stability and refrigeration requirements of superconducting proton linacs such as the Superconducting Proton Linac, which is studied at CERN. Under certain conditions beam-induced HOMs can accumulate sufficient energy to destabilize the beam or quench the superconducting cavities. In order to limit these effects, CERN considers the use of coaxial HOM couplers on the cutoff tubes of the 5-cell superconducting cavities. These couplers consist of resonant antennas shaped as loops or probes, which are designed to couple to potentially dangerous modes while sufficiently rejecting the fundamental mode. In this paper, the design process is presented and a comparison is made between various designs for the high-beta SPL cavities, which operate at 704.4 MHz. The rf and thermal behavior as well as mechanical aspects are discussed. In order to verify the designs, a rapid prototype for the favored coupler was fabricated and characterized on a low-power test-stand.

  16. Pickup Protons: Comparisons using the Three-Dimensional MHD HHMS-PI model and Ulysses SWICS Measurements

    Science.gov (United States)

    Intriligator, Devrie S.; Detman, Thomas; Gloecker, George; Gloeckler, Christine; Dryer, Murray; Sun, Wei; Intriligator, James; Deehr, Charles

    2012-01-01

    We report the first comparisons of pickup proton simulation results with in situ measurements of pickup protons obtained by the SWICS instrument on Ulysses. Simulations were run using the three dimensional (3D) time-dependent Hybrid Heliospheric Modeling System with Pickup Protons (HHMS-PI). HHMS-PI is an MHD solar wind model, expanded to include the basic physics of pickup protons from neutral hydrogen that drifts into the heliosphere from the local interstellar medium. We use the same model and input data developed by Detman et al. (2011) to now investigate the pickup protons. The simulated interval of 82 days in 2003 2004, includes both quiet solar wind (SW) and also the October November 2003 solar events (the Halloween 2003 solar storms). The HHMS-PI pickup proton simulations generally agree with the SWICS measurements and the HHMS-PI simulated solar wind generally agrees with SWOOPS (also on Ulysses) measurements. Many specific features in the observations are well represented by the model. We simulated twenty specific solar events associated with the Halloween 2003 storm. We give the specific values of the solar input parameters for the HHMS-PI simulations that provide the best combined agreement in the times of arrival of the solar-generated shocks at both ACE and Ulysses. We show graphical comparisons of simulated and observed parameters, and we give quantitative measures of the agreement of simulated with observed parameters. We suggest that some of the variations in the pickup proton density during the Halloween 2003 solar events may be attributed to depletion of the inflowing local interstellar medium (LISM) neutral hydrogen (H) caused by its increased conversion to pickup protons in the immediately preceding shock.

  17. International Neutron Radiography Newsletter

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1986-01-01

    At the First World Conference on Neutron Radiography i t was decided to continue the "Neutron Radiography Newsletter", published previously by J.P. Barton, as the "International Neutron Radiography Newsletter" (INRNL), with J.C. Doraanus as editor. The British Journal of Non-Destructive Testing...

  18. Comparison of Diagnostic Accuracy of Radiation Dose-Equivalent Radiography, Multidetector Computed Tomography and Cone Beam Computed Tomography for Fractures of Adult Cadaveric Wrists.

    Science.gov (United States)

    Neubauer, Jakob; Benndorf, Matthias; Reidelbach, Carolin; Krauß, Tobias; Lampert, Florian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Fiebich, Martin; Goerke, Sebastian M

    2016-01-01

    To compare the diagnostic accuracy of radiography, to radiography equivalent dose multidetector computed tomography (RED-MDCT) and to radiography equivalent dose cone beam computed tomography (RED-CBCT) for wrist fractures. As study subjects we obtained 10 cadaveric human hands from body donors. Distal radius, distal ulna and carpal bones (n = 100) were artificially fractured in random order in a controlled experimental setting. We performed radiation dose equivalent radiography (settings as in standard clinical care), RED-MDCT in a 320 row MDCT with single shot mode and RED-CBCT in a device dedicated to musculoskeletal imaging. Three raters independently evaluated the resulting images for fractures and the level of confidence for each finding. Gold standard was evaluated by consensus reading of a high-dose MDCT. Pooled sensitivity was higher in RED-MDCT with 0.89 and RED-MDCT with 0.81 compared to radiography with 0.54 (P = radiography (P radiography. Readers are more confident in their reporting with the cross sectional modalities. Dose equivalent cross sectional computed tomography of the wrist could replace plain radiography for fracture diagnosis in the long run.

  19. Challenging the standard model by high-precision comparisons of the fundamental properties of protons and antiprotons

    Science.gov (United States)

    Ulmer, S.; Mooser, A.; Nagahama, H.; Sellner, S.; Smorra, C.

    2018-03-01

    The BASE collaboration investigates the fundamental properties of protons and antiprotons, such as charge-to-mass ratios and magnetic moments, using advanced cryogenic Penning trap systems. In recent years, we performed the most precise measurement of the magnetic moments of both the proton and the antiproton, and conducted the most precise comparison of the proton-to-antiproton charge-to-mass ratio. In addition, we have set the most stringent constraint on directly measured antiproton lifetime, based on a unique reservoir trap technique. Our matter/antimatter comparison experiments provide stringent tests of the fundamental charge-parity-time invariance, which is one of the fundamental symmetries of the standard model of particle physics. This article reviews the recent achievements of BASE and gives an outlook to our physics programme in the ELENA era. This article is part of the Theo Murphy meeting issue `Antiproton physics in the ELENA era'.

  20. Challenging the standard model by high-precision comparisons of the fundamental properties of protons and antiprotons.

    Science.gov (United States)

    Ulmer, S; Mooser, A; Nagahama, H; Sellner, S; Smorra, C

    2018-03-28

    The BASE collaboration investigates the fundamental properties of protons and antiprotons, such as charge-to-mass ratios and magnetic moments, using advanced cryogenic Penning trap systems. In recent years, we performed the most precise measurement of the magnetic moments of both the proton and the antiproton, and conducted the most precise comparison of the proton-to-antiproton charge-to-mass ratio. In addition, we have set the most stringent constraint on directly measured antiproton lifetime, based on a unique reservoir trap technique. Our matter/antimatter comparison experiments provide stringent tests of the fundamental charge-parity-time invariance, which is one of the fundamental symmetries of the standard model of particle physics. This article reviews the recent achievements of BASE and gives an outlook to our physics programme in the ELENA era.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'. © 2018 The Authors.

  1. High-precision comparison of the antiproton-to-proton charge-to-mass ratio.

    Science.gov (United States)

    Ulmer, S; Smorra, C; Mooser, A; Franke, K; Nagahama, H; Schneider, G; Higuchi, T; Van Gorp, S; Blaum, K; Matsuda, Y; Quint, W; Walz, J; Yamazaki, Y

    2015-08-13

    Invariance under the charge, parity, time-reversal (CPT) transformation is one of the fundamental symmetries of the standard model of particle physics. This CPT invariance implies that the fundamental properties of antiparticles and their matter-conjugates are identical, apart from signs. There is a deep link between CPT invariance and Lorentz symmetry--that is, the laws of nature seem to be invariant under the symmetry transformation of spacetime--although it is model dependent. A number of high-precision CPT and Lorentz invariance tests--using a co-magnetometer, a torsion pendulum and a maser, among others--have been performed, but only a few direct high-precision CPT tests that compare the fundamental properties of matter and antimatter are available. Here we report high-precision cyclotron frequency comparisons of a single antiproton and a negatively charged hydrogen ion (H(-)) carried out in a Penning trap system. From 13,000 frequency measurements we compare the charge-to-mass ratio for the antiproton (q/m)p- to that for the proton (q/m)p and obtain (q/m)p-/(q/m)p − 1 =1(69) × 10(-12). The measurements were performed at cyclotron frequencies of 29.6 megahertz, so our result shows that the CPT theorem holds at the atto-electronvolt scale. Our precision of 69 parts per trillion exceeds the energy resolution of previous antiproton-to-proton mass comparisons as well as the respective figure of merit of the standard model extension by a factor of four. In addition, we give a limit on sidereal variations in the measured ratio of baryonic antimatter, and it sets a new limit on the gravitational anomaly parameter of |α − 1| < 8.7 × 10(-7).

  2. SU-E-T-124: Dosimetric Comparison of HDR Brachytherapy and Intensity Modulated Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J [Purdue University, West Lafayette, IN (United States); Wu, H [IUPUI, Indianapolis, IN (United States); Das, I [Indiana University- School of Medicine, Indianapolis, IN (United States)

    2014-06-01

    Purpose: Brachytherapy is known to be able to deliver more radiation dose to tumor while minimizing radiation dose to surrounding normal tissues. Proton therapy also provides superior dose distribution due to Bragg peak. Since both HDR and Intensity Modulated Proton Therapy (IMPT) are beneficial for their quick dose drop off, our goal in this study is to compare the pace of dose gradient drop-off between HDR and IMPT plans based on the same CT image data-set. In addition, normal tissues sparing were also compared among HDR, IMPT and SBRT. Methods: Five cervical cancer cases treated with EBRT + HDR boost combination with Tandem and Ovoid applicator were used for comparison purpose. Original HDR plans with prescribed dose of 5.5 Gy x 5 fractions were generated and optimized. The 100% isodose line of HDR plans was converted to a dose volume, and treated as CTV for IMPT and SBRT planning. The same HDR CT scans were also used for IMPT plan and SBRT plan for direct comparison. The philosophy of the IMPT and SBRT planning was to create the same CTV coverage as HDR plans. All three modalities treatment plans were compared to each other with a set of predetermined criteria. Results: With similar target volume coverage in cervix cancer boost treatment, HDR provides a slightly sharper dose drop-off from 100% to 50% isodose line, averagely in all directions compared to IMPT. However, IMPT demonstrated more dose gradient drop-off at the junction of the target and normal tissues by providing more normal tissue sparing and superior capability to reduce integral dose. Conclusion: IMPT is capable of providing comparable dose drop-off as HDR. IMPT can be explored as replacement for HDR brachytherapy in various applications.

  3. Blinded comparison of faecal loading on plain radiography versus radio-opaque marker transit studies in the assessment of constipation

    International Nuclear Information System (INIS)

    Cowlam, S.; Vinayagam, R.; Khan, U.; Marsden, S.; Minty, I.; Moncur, P.; Bain, I.; Yiannakou, Y.J.

    2008-01-01

    Aim: To compare faecal loading on plain radiography versus radio-opaque marker transit studies in the assessment of constipation. Methods: The study group was a convenience sample of patients attending the Durham Constipation Clinic. All patients underwent transit studies according to an established protocol, and severity of constipation was assessed contemporaneously using a validated questionnaire (PAC-SYM). Transit studies were performed using radio-opaque markers that were ingested over 3 consecutive days, with a radiograph taken on the fourth day. Digital images of the radiograph were digitally altered to remove all traces of the transit markers without affecting the underlying pattern of faecal loading. Four observers assessed faecal loading independently; two clinicians (C1 and C2) and two radiologists (R1 and R2). C1 and R1 used a previously described formal scoring method of assessing faecal loading, whereas C2 and R2 assessed the images as if they were in a clinic or reporting session, grading the faecal loading as mild, moderate, or severe. Results: One hundred patients were recruited out of 186 presenting in a 2-year period. All patients completed assessments. The correlation between observers was only fair to moderate (r ranging from 0.34-0.51). There were some surprisingly marked disagreements in 10-18% of assessments. The correlation between faecal loading and transit was weak for all observers (r ranging from 0.261-0.311). Symptom severity did not correlate with faecal loading. Conclusion: These results suggest that there is considerable inter-observer variation in the radiological assessment of faecal loading, irrespective of the training or method used by the observer, and that there is very poor correlation with colonic transit. The diagnosis of constipation, and the assessment of severity, is best performed clinically

  4. Blinded comparison of faecal loading on plain radiography versus radio-opaque marker transit studies in the assessment of constipation

    Energy Technology Data Exchange (ETDEWEB)

    Cowlam, S. [Sunderland Royal Hospital, Sunderland (United Kingdom); Vinayagam, R.; Khan, U.; Marsden, S.; Minty, I.; Moncur, P.; Bain, I. [University Hospital of North Durham, Durham (United Kingdom); Yiannakou, Y.J. [University Hospital of North Durham, Durham (United Kingdom)], E-mail: yan.yiannakou@cddft.nhs.uk

    2008-12-15

    Aim: To compare faecal loading on plain radiography versus radio-opaque marker transit studies in the assessment of constipation. Methods: The study group was a convenience sample of patients attending the Durham Constipation Clinic. All patients underwent transit studies according to an established protocol, and severity of constipation was assessed contemporaneously using a validated questionnaire (PAC-SYM). Transit studies were performed using radio-opaque markers that were ingested over 3 consecutive days, with a radiograph taken on the fourth day. Digital images of the radiograph were digitally altered to remove all traces of the transit markers without affecting the underlying pattern of faecal loading. Four observers assessed faecal loading independently; two clinicians (C1 and C2) and two radiologists (R1 and R2). C1 and R1 used a previously described formal scoring method of assessing faecal loading, whereas C2 and R2 assessed the images as if they were in a clinic or reporting session, grading the faecal loading as mild, moderate, or severe. Results: One hundred patients were recruited out of 186 presenting in a 2-year period. All patients completed assessments. The correlation between observers was only fair to moderate (r ranging from 0.34-0.51). There were some surprisingly marked disagreements in 10-18% of assessments. The correlation between faecal loading and transit was weak for all observers (r ranging from 0.261-0.311). Symptom severity did not correlate with faecal loading. Conclusion: These results suggest that there is considerable inter-observer variation in the radiological assessment of faecal loading, irrespective of the training or method used by the observer, and that there is very poor correlation with colonic transit. The diagnosis of constipation, and the assessment of severity, is best performed clinically.

  5. Use of Tomosynthesis for Detection of Bone Erosions of the Foot in Patients With Established Rheumatoid Arthritis: Comparison With Radiography and CT.

    Science.gov (United States)

    Simoni, Paolo; Gérard, Laurent; Kaiser, Marie-Joëlle; Ribbens, Clio; Rinkin, Charline; Malaise, Olivier; Malaise, Michel

    2015-08-01

    The purpose of this study was to compare tomosynthesis with radiography for the detection of bone erosions of the foot in patients with established rheumatoid arthritis (RA) using MDCT as a reference standard. Eighteen consecutive patients with established RA were included. Each patient underwent radiography, tomosynthesis, and CT examinations of the feet on the same day. Two radiologists independently determined the number of bone erosions and the Sharp-van der Heijde score with each of the three imaging modalities. On a total of 216 joints from 18 patients, 216 bone erosions were detected on CT, 215 on tomosynthesis, and 181 with radiography. The mean (± SD) Sharp-van der Heijde score was equivalent for tomosynthesis (18.8 ± 16.8) and CT (19.8 ± 18.5) but was statistically lower for radiography (16.4 ± 18.0) (p = 0.030). The respective overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for tomosynthesis were 80%, 75%, 78%, 76%, and 80%, whereas the respective corresponding values for radiography were 66%, 81%, 74%, 77%, and 71%. The radiation burden of tomosynthesis was almost equivalent to that of radiography. Tomosynthesis has a higher sensitivity than radiography to detect bone erosions of the foot in patients with established RA and imparts an almost equivalent radiation burden.

  6. PROTON MICROSCOPY AT FAIR

    International Nuclear Information System (INIS)

    Merrill, F. E.; Mariam, F. G.; Golubev, A. A.; Turtikov, V. I.; Varentsov, D.

    2009-01-01

    Proton radiography was invented in the 1990's at Los Alamos National Laboratory (LANL) as a diagnostic to study dynamic material properties under extreme pressures, strain and strain rate. Since this time hundreds of dynamic proton radiography experiments have been performed at LANL and a facility has been commissioned at the Institute for Theoretical and Experimental Physics (ITEP) in Russia for similar applications in dynamic material studies. Recently an international effort has investigated a new proton radiography capability for the study of dynamic material properties at the Facility for Anti-proton and Ion Research (FAIR) located in Darmstadt, Germany. This new Proton microscope for FAIR(PRIOR) will provide radiographic imaging of dynamic systems with unprecedented spatial, temporal and density resolution, resulting in a window for understanding dynamic material properties at new length scales. It is also proposed to install the PRIOR system at the GSI Helmholtzzentrum fuer Schwerionenforschung before installation at FAIR for dynamic experiments with different drivers including high explosives, pulsed power and lasers. The design of the proton microscope and expected radiographic performance is presented.

  7. Comparison between diagnostic ultrasonography and radiography in the evaluation of horses and cattle with thoracic disease: 56 cases (1984-1985)

    International Nuclear Information System (INIS)

    Reef, V.B.; Boy, M.G.; Reid, C.F.; Elser, A.

    1991-01-01

    The results of radiography and ultrasonography were compared on 56 horses and cows with lower respiratory tract disease. Ultrasonography was more sensitive than radiography for the detection of small pleural effusions and consolidations in large animals. The side of the thorax affected and the character of the pleural fluid and lung in large animals with pleural effusion can be evaluated ultrasonographically. The periphery of the lung must be affected to characterize pulmonary lesions ultrasonographically. Radiography is the best technique to characterize lesions deep within the lung when the periphery of the lung is normal

  8. Polarization measurements in high energy elastic scattering of pions, kaons, protons and antiprotons on protons and comparison with Regge phenomenology

    International Nuclear Information System (INIS)

    Gaidot, A.; Bruneton, C.; Bystricky, J.; Cozzika, G.; Deregel, J.; Ducros, Y.; Khantine-Langlois, F.; Lehar, F.; Lesquen, A. de; Merlo, J.P.; Miyashita, S.; Movchet, J.; Pierrard, J.; Raoul, J.C.; Van Rossum, L.; Kanavets, V.P.

    1975-01-01

    The polarization parameter P has been measured for elastic scattering on polarized protons, of π - , K - and anti-p at 40GeV/c and of π + , K + and p at 45GeV/c. Four-momentum transfer ranges from -0.08 to -1.8(GeV/c) 2 for π - p and pp, and from -0.08 to -1.2(GeV/c) 2 for π + , K + or K - and anti-p [fr

  9. Dosimetric Comparison of Three-Dimensional Conformal Proton Radiotherapy, Intensity-Modulated Proton Therapy, and Intensity-Modulated Radiotherapy for Treatment of Pediatric Craniopharyngiomas

    Energy Technology Data Exchange (ETDEWEB)

    Boehling, Nicholas S. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Grosshans, David R., E-mail: dgrossha@mdanderson.org [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Bluett, Jaques B. [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Palmer, Matthew T. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Song, Xiaofei; Amos, Richard A.; Sahoo, Narayan [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Meyer, Jeffrey J.; Mahajan, Anita; Woo, Shiao Y. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

    2012-02-01

    Purpose: Cranial irradiation in pediatric patients is associated with serious long-term adverse effects. We sought to determine whether both three-dimensional conformal proton radiotherapy (3D-PRT) and intensity-modulated proton therapy (IMPT) compared with intensity-modulated radiotherapy (IMRT) decrease integral dose to brain areas known to harbor neuronal stem cells, major blood vessels, and other normal brain structures for pediatric patients with craniopharyngiomas. Methods and Materials: IMRT, forward planned, passive scattering proton, and IMPT plans were generated and optimized for 10 pediatric patients. The dose was 50.4 Gy (or cobalt Gy equivalent) delivered in 28 fractions with the requirement for planning target volume (PTV) coverage of 95% or better. Integral dose data were calculated from differential dose-volume histograms. Results: The PTV target coverage was adequate for all modalities. IMRT and IMPT yielded the most conformal plans in comparison to 3D-PRT. Compared with IMRT, 3D-PRT and IMPT plans had a relative reduction of integral dose to the hippocampus (3D-PRT, 20.4; IMPT, 51.3%{sup Asterisk-Operator }), dentate gyrus (27.3, 75.0%{sup Asterisk-Operator }), and subventricular zone (4.5, 57.8%{sup Asterisk-Operator }). Vascular organs at risk also had reduced integral dose with the use of proton therapy (anterior cerebral arteries, 33.3{sup Asterisk-Operator }, 100.0%{sup Asterisk-Operator }; middle cerebral arteries, 25.9%{sup Asterisk-Operator }, 100%{sup Asterisk-Operator }; anterior communicating arteries, 30.8{sup Asterisk-Operator }, 41.7%{sup Asterisk-Operator }; and carotid arteries, 51.5{sup Asterisk-Operator }, 77.6{sup Asterisk-Operator }). Relative reduction of integral dose to the infratentorial brain (190.7{sup Asterisk-Operator }, 109.7%{sup Asterisk-Operator }), supratentorial brain without PTV (9.6, 26.8%{sup Asterisk-Operator }), brainstem (45.6, 22.4%{sup Asterisk-Operator }), and whole brain without PTV (19.4{sup Asterisk

  10. Onsets of Solar Proton Events in Satellite and Ground Level Observations: A Comparison

    Science.gov (United States)

    He, Jing; Rodriguez, Juan V.

    2018-03-01

    The early detection of solar proton event onsets is essential for protecting humans and electronics in space, as well as passengers and crew at aviation altitudes. Two commonly compared methods for observing solar proton events that are sufficiently large and energetic to be detected on the ground through the creation of secondary radiation—known as ground level enhancements (GLEs)—are (1) a network of ground-based neutron monitors (NMs) and (2) satellite-based particle detectors. Until recently, owing to the different time resolution of the two data sets, it has not been feasible to compare these two types of observations using the same detection algorithm. This paper presents a comparison between the two observational platforms using newly processed >100 MeV 1 min count rates and fluxes from National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellite (GOES) 8-12 satellites, and 1 min count rates from the Neutron Monitor Database. We applied the same detection algorithm to each data set (tuned to the different background noise levels of the instrument types). Seventeen SPEs with GLEs were studied: GLEs 55-70 from Solar Cycle 23 and GLE 71 from Solar Cycle 24. The median difference in the event detection times by GOES and NM data is 0 min, indicating no innate benefit in time of either system. The 10th, 25th, 75th, and 90th percentiles of the onset time differences (GOES minus NMs) are -7.2 min, -1.5 min, 2.5 min, and 4.2 min, respectively. This is in contrast to previous studies in which NM detections led GOES by 8 to 52 min without accounting for different alert protocols.

  11. The usefulness of whole body bone mineral densitometry in the osteopenia of preterm infants: comparison with the wrist radiography and biochemical parameters

    International Nuclear Information System (INIS)

    Cheon, Bong Jin; Huh, Jin Do; Shin, Sang Bum; Cheon, Byung Kook; Joh, Young Duk; Kwon, Jeong Mi; Jeon, Seong Sook

    1997-01-01

    To evaluate the usefulness of whole body bone mineral densitometry in the diagnosis of frequent osteopenia of preterm infants by comparison with the wrist radiographs and biochemical parameters. From January 1995 to January 1996, we obtained whole body bone mineral density(BMD) studies using dual energy X-ray absorptiometry(DXA) and wrist radiographs of 39 preterm infants. They were divided into three groups according to birth weight, under 1500g, 1501g to 2000g and above 2000g, and four grades of skeletal change, as seen on wrist radiography, according to the scoring method of Koo et al. Groups of birth weight and grades of skeletal change were then correlated with whole body BMD and biochemical parameters. For comparison, normal data were obtained from 13 infants born at full term. Data were analyzed by one way analysis of variation(ANOVA) and correlation and regression analysis. A p-value of less than 0.05 was considered significant. Whole body BMDs were significantly lower in the more premature and smaller birth weight infants(r=0.77, p=0.0000), and in the higher grade of skeletal change(r-0.5276, p=0.0000). Aggravated skeletal changes were found in infants with lower birth weight(r= -0.3822, p=0.01). Interobserver variation in grading skeletal change was 42.9%, and intraobserver variation was 18.4%. Biochemical parameters such as serum calcium, phosphate, alkaline phosphatase, parathromone, calcitonin and 25-hydroxy-vitamine D did not vary significantly according to either birth weight or skeletal change(p > 0.05). Premature osteopenia is more effectively diagnosed by measuring whole body BMD using DXA than by grading radiographical skeletal change or by biochemical parameters

  12. The usefulness of whole body bone mineral densitometry in the osteopenia of preterm infants: comparison with the wrist radiography and biochemical parameters

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, Bong Jin; Huh, Jin Do; Shin, Sang Bum; Cheon, Byung Kook; Joh, Young Duk [Kosin Univ. Gospel Hospital, Pusan (Korea, Republic of); Kwon, Jeong Mi; Jeon, Seong Sook [Ilsin Christian Hospital, Pusan (Korea, Republic of)

    1997-02-01

    To evaluate the usefulness of whole body bone mineral densitometry in the diagnosis of frequent osteopenia of preterm infants by comparison with the wrist radiographs and biochemical parameters. From January 1995 to January 1996, we obtained whole body bone mineral density(BMD) studies using dual energy X-ray absorptiometry(DXA) and wrist radiographs of 39 preterm infants. They were divided into three groups according to birth weight, under 1500g, 1501g to 2000g and above 2000g, and four grades of skeletal change, as seen on wrist radiography, according to the scoring method of Koo et al. Groups of birth weight and grades of skeletal change were then correlated with whole body BMD and biochemical parameters. For comparison, normal data were obtained from 13 infants born at full term. Data were analyzed by one way analysis of variation(ANOVA) and correlation and regression analysis. A p-value of less than 0.05 was considered significant. Whole body BMDs were significantly lower in the more premature and smaller birth weight infants(r=0.77, p=0.0000), and in the higher grade of skeletal change(r-0.5276, p=0.0000). Aggravated skeletal changes were found in infants with lower birth weight(r= -0.3822, p=0.01). Interobserver variation in grading skeletal change was 42.9%, and intraobserver variation was 18.4%. Biochemical parameters such as serum calcium, phosphate, alkaline phosphatase, parathromone, calcitonin and 25-hydroxy-vitamine D did not vary significantly according to either birth weight or skeletal change(p > 0.05). Premature osteopenia is more effectively diagnosed by measuring whole body BMD using DXA than by grading radiographical skeletal change or by biochemical parameters.

  13. The role of whole body spiral CT in the primary work-up of polytrauma patients - comparison with conventional radiography and abdominal sonography; Die Rolle der Ganzkoerper-Spiral-CT bei der Primaerdiagnostik polytraumatisierter Patienten - Vergleich mit konventioneller Radiographie und Abdomensonographie

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, T.; Schlippenbach, J. von; Wolf, K.J. [Klinik und Poliklinik fuer Radiologie und Nuklearmedizin, Charite - Campus Benjamin Franklin (Germany); Stahel, P.F.; Ertel, W. [Klinik fuer Unfall- und Wiederherstellungschirurgie, Charite - Campus Benjamin Franklin (Germany)

    2004-08-01

    Purpose: To evaluate the role of routine 'whole body spiral CT' in the primary work-up of polytrauma patients for injuries of the thorax, abdomen and spine, and to compare the results with those of conventional radiography of the chest and spine and abdominal ultrasound. Materials and Methods: Fifty consecutive polytrauma patients underwent contrast-enhanced single slice spiral CT (5 mm collimation) from the vertex to the floor of the pelvis as part of the primary work-up after emergency room admission. Overlapping high resolution sections and sagittal reformations of the spine were obtained. Reports of additional chest radiographs (n=43), abdominal ultrasound examinations (n=47) and spine radiographs (n=36) performed in the emergency room were available for retrospective comparison. The 'final diagnoses', which served as the standard of reference, were taken from the patients' records using all information that became available until discharge or death, such as findings from further imaging, surgery and autopsy. Results: CT showed 109 (97%) of 112 thoracic and abdominal soft-tissue injuries. Relevant injuries missed were an early splenic laceration and an early pelvic hematoma, both of which became clinically apparent several hours later. There were 4 false positive CT findings. Conventional chest radiography demonstrated only 20% of thoracic and sonography 22% of abdominal injuries. Chest radiography and sonography produced 2 false-positive findings each. CT showed 66 (87%) of 76 vertebral fractures including all 19 unstable ones. CT missed 5 anterior vertebral body and 5 spinous/transverse process fractures. Conventional radiography found 71% of vertebral fractures including only 50% of the unstable one. (orig.)

  14. An in vitro comparison of diagnostic abilities of conventional radiography, storage phosphor, and cone beam computed tomography to determine occlusal and approximal caries

    Energy Technology Data Exchange (ETDEWEB)

    Kayipmaz, Saadettin, E-mail: kayipmaz@ktu.edu.tr [Karadeniz Technical University, Faculty of Dentistry, Department of Oral Diagnosis and Radiology, Farabi, 61080 Trabzon (Turkey); Sezgin, Omer Said, E-mail: omersaidsezgin@gmail.com [Karadeniz Technical University, Faculty of Dentistry, Department of Oral Diagnosis and Radiology, Farabi, 61080 Trabzon (Turkey); Saricaoglu, Senem Tugra, E-mail: senem_tugra@hotmail.com [Karadeniz Technical University, Faculty of Dentistry, Department of Oral Diagnosis and Radiology, Farabi, 61080 Trabzon (Turkey); Can, Gamze, E-mail: gcanktu@yahoo.com [Karadeniz Technical University Faculty of Medicine Department of Public Health (Turkey)

    2011-11-15

    Aim: The aim of this study was to compare conventional radiography, storage phosphor plate, and cone beam computed tomography for in vitro determination of occlusal and approximal caries. Methods: A total of 72 extracted human premolar and molar teeth were selected. Teeth were radiographed with conventional intraoral radiography, a storage phosphor plate system, and cone beam computed tomography and evaluated by two observers. The teeth were then separated and examined with a stereomicroscope and a scanner at approximately 8x magnification. Results: CBCT was statistically superior to conventional radiography and phosphor plate for determining occlusal caries. No significant difference from CBCT, conventional radiography and the phosphor plate system for determining approximal caries was found. Conclusion: The CBCT system may be used as an auxiliary method for the detection of caries.

  15. An in vitro comparison of diagnostic abilities of conventional radiography, storage phosphor, and cone beam computed tomography to determine occlusal and approximal caries

    International Nuclear Information System (INIS)

    Kayipmaz, Saadettin; Sezgin, Omer Said; Saricaoglu, Senem Tugra; Can, Gamze

    2011-01-01

    Aim: The aim of this study was to compare conventional radiography, storage phosphor plate, and cone beam computed tomography for in vitro determination of occlusal and approximal caries. Methods: A total of 72 extracted human premolar and molar teeth were selected. Teeth were radiographed with conventional intraoral radiography, a storage phosphor plate system, and cone beam computed tomography and evaluated by two observers. The teeth were then separated and examined with a stereomicroscope and a scanner at approximately 8x magnification. Results: CBCT was statistically superior to conventional radiography and phosphor plate for determining occlusal caries. No significant difference from CBCT, conventional radiography and the phosphor plate system for determining approximal caries was found. Conclusion: The CBCT system may be used as an auxiliary method for the detection of caries.

  16. Fractures of the thoracic spine in patients with minor trauma: Comparison of diagnostic accuracy and dose of biplane radiography and MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Karul, M., E-mail: m.karul@uke.de [Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Bannas, P.; Schoennagel, B.P.; Hoffmann, A.; Wedegaertner, U.; Adam, G.; Yamamura, J. [Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany)

    2013-08-15

    Objectives: To investigate the accuracy of biplane radiography in the detection of fractures of the thoracic spine in patients with minor trauma using multidetector computed tomography (MDCT) as the reference and to compare the dose of both techniques. Methods: 107 consecutive trauma patients with suspected fractures of the thoracic spine on physical examination were included. All had undergone biplane radiography first, followed by a MDCT scan between October 2008 and October 2012. A fourfold table was used for the classification of the screening test results. Both the Chi-square test (χ{sup 2}) and the mean dose-length product (DLP) were used to compare the diagnostic methods. Results: MDCT revealed 77 fractures in 65/107 patients (60.7%). Biplane radiography was true positive in 32/107 patients (29.9%), false positive in 19/107 patients (17.8%), true negative in 23/107 (21.5%) and false negative in 33/107 patients (30.8%), showing a sensitivity of 49.2%, a specificity of 54.7%, a positive predictive value (PPV) of 62.7%, a negative predictive value (NPV) of 41.1%, and an accuracy of 51.4%. The presence of a fracture on biplane radiography was highly statistical significant, if this was simultaneously proven by MDCT (χ{sup 2} = 7.6; p = 0.01). None of the fractures missed on biplane radiography was unstable. The mean DLP on biplane radiography was 14.5 mGy cm (range 1.9–97.8) and on MDCT 374.6 mGy cm (range 80.2–871). Conclusions: The sensitivity and the specificity of biplane radiography in the diagnosis of fractures of the thoracic spine in patients with minor trauma are low. Considering the wide availability of MDCT that is usually necessary for taking significant therapeutic steps, the indication for biplane radiography should be very restrictive.

  17. Evidence-based radiography

    International Nuclear Information System (INIS)

    Hafslund, Bjorg; Clare, Judith; Graverholt, Birgitte; Wammen Nortvedt, Monica

    2008-01-01

    Evidence-based practice (EBP) offers the integration of the best research evidence with clinical knowledge and expertise and patient values. EBP is a well known term in health care. This paper discusses the implementation of EBP into radiography and introduces the term evidence-based radiography. Evidence-based radiography is radiography informed and based on the combination of clinical expertise and the best available research-based evidence, patient preferences and resources available. In Norway, EBP in radiography is being debated and radiographers are discussing the challenges of implementing EBP in both academic and clinical practice. This discussion paper explains why EBP needs to be a basis for a radiography curriculum and a part of radiographers' practice. We argue that Norwegian radiographers must increase participation in research and developing practice within their specific radiographic domain

  18. Diagnostic imaging in polytrauma: comparison of radiation exposure from whole-body MSCT and conventional radiography with organ-specific CT

    International Nuclear Information System (INIS)

    Wedegaertner, U.; Lorenzen, M.; Weber, C.; Adam, G.; Nagel, H.D.

    2004-01-01

    Purpose: To compare the radiation dose of whole-body multislice CT (MSCT) and conventional radiography with organ-specific CT in polytrauma. Materials and Methods: The whole-body MSCT encompassing brain, neck and midface, chest, abdomen and pelvis was performed on a Somatom Volume Zoom (Siemens). Conventional radiography consisted of chest and cervical, thoracic and lumbar spine in two views as well as pelvis. Polymat, Siemens. Three combinations of organ specific CT were chosen: CT examination of (1) head and cervical spine, (2) head, cervical spine and chest, (3) head, cervical spine and abdomen. The effective doses of whole-body MSCT and conventional radiography with organ-specific CT were calculated. Results: Effective doses were 20 mSv for whole-body MSCT, 2 mSv for conventional x-ray, and 5 mSv for combination (1), 8 mSv for combination (2) and (3) 16 mSv for combination (3) of the organ-specific CT. The ratio of radiation dose between whole-body MSCT and radiography was 10: 1. This ratio was reduced to 3: 1, 2: 1 and 1: 1 when a combination of radiography and CT was performed. Conclusions: Whole-body MSCT in polytrauma compared to conventional radiography with organ-specific CT induces a threefold increased dose in unfavorable situations and no increased dose in favorable situations. Nevertheless, routine use of whole-body MSCT should be critically evaluated and should be adapted to the clinical benefit. (orig.) [de

  19. Comparison of digital selenium radiography with an analog screen-film system in the diagnostic process of pneumoconiosis according to ILO classification

    International Nuclear Information System (INIS)

    Zaehringer, M.; Winnekendonk, G.; Gossmann, A.; Krueger, K.; Krug, B.

    2001-01-01

    Purpose: The aim of the study was to determine the diagnostic value of digital selenium radiography in patients with pneumoconiosis. For this purpose chest X-rays by digital selenium radiography and analog screen-film system were compared according to the ILO classification of pneumoconiosis. Method: After approval of the study by the local ethic commission and the Federal German Office for Radiation Protection 50 patients were subjected to X-rays by digital selenium radiography (Thoravision; Philips Medical Systems, Hamburg, Germany) and analog screen-film system of the same day within the scope of an industrial medicine preventive checkup. Four investigators rated the chest X-rays according to the ILO classification of pneumoconiosis. Results: The findings demonstrated by chest X-rays according to ILO classification were rated similar by digital selenium radiography and analog screen film systems. Image quality of the digital pictures was rated significantly better. Conclusion: The use of digital selenium radiography in evaluating chest X-rays according to the ILO classification does not result in over- or underestimation of pulmonary pathologies. Hence, in the diagnosis of pneumoconiosis, digital selenium radiography can replace the tested analog screen-film system. (orig.) [de

  20. Dosimetric comparison of proton and photon three-dimensional, conformal, external beam accelerated partial breast irradiation techniques

    International Nuclear Information System (INIS)

    Kozak, Kevin R.; Katz, Angela; Adams, Judith C.; Crowley, Elizabeth M.; Nyamwanda, Jacqueline A.C.; Feng, Jennifer K.C.; Doppke, Karen P.; DeLaney, Thomas F.; Taghian, Alphonse G.

    2006-01-01

    Purpose: To compare the dosimetry of proton and photon-electron three-dimensional, conformal, external beam accelerated partial breast irradiation (3D-CPBI). Methods and Materials: Twenty-four patients with fully excised, Stage I breast cancer treated with adjuvant proton 3D-CPBI had treatment plans generated using the mixed-modality, photon-electron 3D-CPBI technique. To facilitate dosimetric comparisons, planning target volumes (PTVs; lumpectomy site plus 1.5-2.0 cm margin) and prescribed dose (32 Gy) were held constant. Plans were optimized for PTV coverage and normal tissue sparing. Results: Proton and mixed-modality plans both provided acceptable PTV coverage with 95% of the PTV receiving 90% of the prescribed dose in all cases. Both techniques also provided excellent dose homogeneity with a dose maximum exceeding 110% of the prescribed dose in only one case. Proton 3D-CPBI reduced the volume of nontarget breast tissue receiving 50% of the prescribed dose by an average of 36%. Statistically significant reductions in the volume of total ipsilateral breast receiving 100%, 75%, 50%, and 25% of the prescribed dose were also observed. The use of protons resulted in small, but statistically significant, reductions in the radiation dose delivered to 5%, 10%, and 20% of ipsilateral and contralateral lung and heart. The nontarget breast tissue dosimetric advantages of proton 3D-CPBI were not dependent on tumor location, breast size, PTV size, or the ratio of PTV to breast volume. Conclusions: Compared to photon-electron 3D-CPBI, proton 3D-CPBI significantly reduces the volume of irradiated nontarget breast tissue. Both approaches to accelerated partial breast irradiation offer exceptional lung and heart sparing

  1. Dose optimisation in computed radiography

    International Nuclear Information System (INIS)

    Schreiner-Karoussou, A.

    2005-01-01

    After the installation of computed radiography (CR) systems in three hospitals in Luxembourg a patient dose survey was carried out for three radiographic examinations, thorax, pelvis and lumbar spine. It was found that the patient doses had changed in comparison with the patient doses measured for conventional radiography in the same three hospitals. A close collaboration between the manufacturers of the X-ray installations, the CR imaging systems and the medical physicists led to the discovery that the speed class with which each radiographic examination was to be performed, had been ignored, during installation of the digital imaging systems. A number of procedures were carried out in order to calibrate and program the X-ray installations in conjunction with the CR systems. Following this optimisation procedure, a new patient dose survey was carried out for the three radiographic examinations. It was found that patient doses for the three hospitals were reduced. (authors)

  2. COMPARISON OF RESPONSE OF PASSIVE DOSIMETRY SYSTEMS IN SCANNING PROTON RADIOTHERAPY-A STUDY USING PAEDIATRIC ANTHROPOMORPHIC PHANTOMS.

    Science.gov (United States)

    Kneževic, Ž; Ambrozova, I; Domingo, C; De Saint-Hubert, M; Majer, M; Martínez-Rovira, I; Miljanic, S; Mojzeszek, N; Porwol, P; Ploc, O; Romero-Expósito, M; Stolarczyk, L; Trinkl, S; Harrison, R M; Olko, P

    2017-11-18

    Proton beam therapy has advantages in comparison to conventional photon radiotherapy due to the physical properties of proton beams (e.g. sharp distal fall off, adjustable range and modulation). In proton therapy, there is the possibility of sparing healthy tissue close to the target volume. This is especially important when tumours are located next to critical organs and while treating cancer in paediatric patients. On the other hand, the interactions of protons with matter result in the production of secondary radiation, mostly neutrons and gamma radiation, which deposit their energy at a distance from the target. The aim of this study was to compare the response of different passive dosimetry systems in mixed radiation field induced by proton pencil beam inside anthropomorphic phantoms representing 5 and 10 years old children. Doses were measured in different organs with thermoluminescent (MTS-7, MTS-6 and MCP-N), radiophotoluminescent (GD-352 M and GD-302M), bubble and poly-allyl-diglycol carbonate (PADC) track detectors. Results show that RPL detectors are the less sensitive for neutrons than LiF TLDs and can be applied for in-phantom dosimetry of gamma component. Neutron doses determined using track detectors, bubble detectors and pairs of MTS-7/MTS-6 are consistent within the uncertainty range. This is the first study dealing with measurements on child anthropomorphic phantoms irradiated by a pencil scanning beam technique. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Inter-comparison of Dose Distributions Calculated by FLUKA, GEANT4, MCNP, and PHITS for Proton Therapy

    Science.gov (United States)

    Yang, Zi-Yi; Tsai, Pi-En; Lee, Shao-Chun; Liu, Yen-Chiang; Chen, Chin-Cheng; Sato, Tatsuhiko; Sheu, Rong-Jiun

    2017-09-01

    The dose distributions from proton pencil beam scanning were calculated by FLUKA, GEANT4, MCNP, and PHITS, in order to investigate their applicability in proton radiotherapy. The first studied case was the integrated depth dose curves (IDDCs), respectively from a 100 and a 226-MeV proton pencil beam impinging a water phantom. The calculated IDDCs agree with each other as long as each code employs 75 eV for the ionization potential of water. The second case considered a similar condition of the first case but with proton energies in a Gaussian distribution. The comparison to the measurement indicates the inter-code differences might not only due to different stopping power but also the nuclear physics models. How the physics parameter setting affect the computation time was also discussed. In the third case, the applicability of each code for pencil beam scanning was confirmed by delivering a uniform volumetric dose distribution based on the treatment plan, and the results showed general agreement between each codes, the treatment plan, and the measurement, except that some deviations were found in the penumbra region. This study has demonstrated that the selected codes are all capable of performing dose calculations for therapeutic scanning proton beams with proper physics settings.

  4. JRR-3 neutron radiography facility

    International Nuclear Information System (INIS)

    Matsubayashi, M.; Tsuruno, A.

    1992-01-01

    JRR-3 neutron radiography facility consists of thermal neutron radiography facility (TNRF) and cold neutron radiography facility (CNRF). TNRF is installed in JRR-3 reactor building. CNRF is installed in the experimental beam hall adjacent to the reactor building. (author)

  5. Specific radiography technique

    International Nuclear Information System (INIS)

    Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

    2008-01-01

    Beside radiography testing using x-ray machine and gamma source, there are several technique that developed specifically to complete the testing that cannot be done with the two earlier. This technique was specific based on several factor, for the example, the advantages of neutron and electron using to show the image was unique compare to x-ray and gamma. Besides that, these special radiography techniques maybe differ in how to detect the radiation get through the object. These technique can used to inspect thin or specimen that contained radioactive material. There are several technique will discussed in this chapter such as neutron radiography, electron radiography, fluoroscopy and also autoradiography.

  6. Digital radiography of the skeleton using a large-area detector based on amorphous silicon technology: Image quality and potential for dose reduction in comparison with screen-film radiography

    International Nuclear Information System (INIS)

    Volk, M.; Strotzer, M.; Holzkneckt, N.; Manke, C.; Lenhart, M.; Gmeinwieser, J.; Link, J.; Reiser, M.; Feuerback, S.

    2000-01-01

    AIM: The purpose of this study was to evaluate a large-area, flat-panel X-ray detector (FD), based on caesium-iodide (CsI) and amorphous silicon (a-Si) with respect to skeletal radiography. Conventional images were compared with digital radiographs using identical and reduced radiation doses. MATERIALS AND METHODS: Thirty consecutive patients were studied prospectively using conventional screen-film radiography (SFR; detector dose 2.5 μGy). Digital images were taken from the same patients with detector doses of 2.5, 1.25 and 0.625 μGy, respectively. The active-matrix detector had a panel size of 43 x 43 cm, a matrix of 3 x 3K, and a pixel size of 143 μm. All hard copies were presented in a random order to eight independent observers, who rated image quality according to subjective quality criteria. Results were assessed for significance using the Student's t -test (confidence level 95%). RESULTS: A statistically significant preference for digital over conventional images was revealed for all quality criteria, except for over-exposure (detector dose 2.5 μGy). Digital images with a 50% dose showed a small, statistically not significant, inferiority compared with SFR. The FD-technique was significantly inferior to SFR at 75% dose reduction regarding bone cortex and trabecula, contrast and overall impression. No statistically significant differences were found with regard to over- and under-exposure and soft tissue presentation. CONCLUSION: Amorphous silicon-based digital radiography yields good image quality. The potential for dose reduction depends on the clinical query. Volk, M. (2000)

  7. Physical and Clinical Comparison between a Screen-Film System and a Dual-Side Reading Mammography-Dedicated Computed Radiography System

    International Nuclear Information System (INIS)

    Rivetti, S.; Canossi, B.; Battista, R.; Vetruccio, E.; Torricelli, P.; Lanconelli, N.; Danielli, C.; Borasi, G.

    2009-01-01

    Background: Digital mammography systems, thanks to a physical performance better than conventional screen-film units, have the potential of reducing the dose to patients, without decreasing the diagnostic accuracy. Purpose: To achieve a physical and clinical comparison between two systems: a screen-film plate and a dual-side computed radiography system (CRM; FUJIFILM FCR 5000 MA). Material and Methods: A unique feature of the FCR 5000 MA system is that it has a clear support medium, allowing light emitted during the scanning process to be detected on the 'back' of the storage phosphor plate, considerably improving the system's efficiency. The system's physical performance was tested by means of a quantitative analysis, with calculation of the modulation transfer function, detective quantum efficiency, and contrast-detail analysis; subsequently, the results were compared with those achieved using a screen-film system (SFM; Eastmann Kodak MinR-MinR 2000). A receiver operating characteristic (ROC) analysis was then performed on 120 paired clinical images obtained in a craniocaudal projection with the conventional SFM system under standard exposure conditions and also with the CRM system working with a dose reduced by 35% (average breast thickness: 4.3 cm; mean glandular dose: 1.45 mGy). CRM clinical images were interpreted both in hard copy and in soft copy. Results: The ROC analysis revealed that the performances of the two systems (SFM and CRM with reduced dose) were similar (P>0.05): the diagnostic accuracy of the two systems, when valued in terms of the area underneath the ROC curve, was found to be 0.74 for the SFM, 0.78 for the CRM (hard copy), and 0.79 for the CRM (soft copy). Conclusion: The outcome obtained from our experiments shows that the use of the dual-side CRM system is a very good alternative to the screen-film system

  8. Comparison of platinum/MWCNTs Nanocatalysts Synthesis Processes for Proton Exchange Membrane Fuel Cells

    Science.gov (United States)

    Liu, Xuan

    Due to the growing concerns on the depletion of petroleum based energy resources and climate change; fuel cell technologies have received much attention in recent years. Proton exchange membrane fuel cell (PEMFCs) features high energy conversion efficiency and nearly zero greenhouse gas emissions, because of its combination of the hydrogen oxidation reaction (HOR) at anode side and oxygen reduction reaction (ORR) at cathode side. Synthesis of Pt nanoparticles supported on multi walled carbon nanotubes (MWCNTs) possess a highly durable electrochemical surface area (ESA) and show good power output on proton exchange membrane (PEM) fuel cell performance. Platinum on multi-walled carbon nanotubes (MWCNTs) support were synthesized by two different processes to transfer PtCl62- from aqueous to organic phase. While the first method of Pt/MWCNTs synthesis involved dodecane thiol (DDT) and octadecane thiol (ODT) as anchoring agent, the second method used ammonium lauryl sulfate (ALS) as the dispersion/anchoring agent. The particle size and distribution of platinum were examined by high-resolution transmission electron microscope (HRTEM). The TEM images showed homogenous distribution and uniform particle size of platinum deposited on the surface of MWCNTs. The single cell fuel cell performance of the Pt/MWCNTs synthesized thiols and ALS based electrode containing 0.2 (anode) and 0.4 mg (cathode) Pt.cm-2 were evaluated using Nafion-212 electrolyte with H2 and O2 gases at 80 °C and ambient pressure. The catalyst synthesis with ALS is relatively simple compared to that with thiols and also showed higher performance (power density reaches about 1070 mW.cm -2). The Electrodes with Pt/MWCNTs nanocatalysts synthesized using ALS were characterized by cyclic voltammetry (CV) for durability evaluation using humidified H2 and N2 gases at room temperature (21 °C) along with commercial Pt/C for comparison. The ESA measured by cyclic voltammetry between 0.15 and 1.2 V showed significant

  9. Basic studies of radiation image diagnosis in veterinary medicine, 1: Comparison of the resolution of computed tomography, scanography and conventional radiography in an equine thoracic phantom

    International Nuclear Information System (INIS)

    Shida, T.; Suganuma, T.; Hashizume, T.

    1984-01-01

    In radiography of the thorax and abdomen of a large animal, the extreme thickness of the body causes a large amount of scattered radiation, which makes it difficult to obtain sharp images. The image resolutions of radiographs obtained by applying conventional radiography, scanography and computed tomography [CT] on an equine thoracic phantom were compared. Tubes of various inside diameters, used to simulate the pulmonary vessels were placed in an equine thoracic phantom and radiographed by CT, scanography and conventional radiography so as to compare the various degrees of resolution of the images of the tubes obtained by these methods. CT and scanography both gave a higher resolution index than conventional radiography, and both provided recognizable images of tubes < 2 mm in diameter, which conventional radiography failed to do. Scanography and CT can be used to obtain high-quality images of the thorax and abdomen of large animals. The image quality was compared using the resolution index (RI). The RI would be a wholly practical and comprehensive index for resolution because it includes 3 factors, contrast, sharpness and magnification, and yet is easy to calculate

  10. Proton energy and scattering angle radiographs to improve proton treatment planning : a Monte Carlo study

    NARCIS (Netherlands)

    Biegun, Aleksandra; Takatsu, Jun; Nakaji, Taku; van Goethem, Marc-Jan; van der Graaf, Emiel; Koffeman, E.; Visser, Jan; Brandenburg, Sijtze

    2016-01-01

    The novel proton radiography imaging technique has a large potential to be used in direct measurement of the proton energy loss (proton stopping power, PSP) in various tissues in the patient. The uncertainty of PSPs, currently obtained from translation of X-ray Computed Tomography (xCT) images,

  11. Digital chest radiography

    DEFF Research Database (Denmark)

    Debess, Jeanne Elisabeth; Johnsen, Karen Kirstine; Thomsen, Henrik

    on collimation and dose reduction in digital chest radiography Methods and Materials A retrospective study of digital chest radiography is performed to evaluate the primary x-ray tube collimation of the PA and lateral radiographs. Data from one hundred fifty self-reliant female patients between 15 and 55 years...

  12. Identification of Nasal Bone Fractures on Conventional Radiography and Facial CT: Comparison of the Diagnostic Accuracy in Different Imaging Modalities and Analysis of Interobserver Reliability

    International Nuclear Information System (INIS)

    Baek, Hye Jin; Kim, Dong Wook; Ryu, Ji Hwa; Lee, Yoo Jin

    2013-01-01

    There has been no study to compare the diagnostic accuracy of an experienced radiologist with a trainee in nasal bone fracture. To compare the diagnostic accuracy between conventional radiography and computed tomography (CT) for the identification of nasal bone fractures and to evaluate the interobserver reliability between a staff radiologist and a trainee. A total of 108 patients who underwent conventional radiography and CT after acute nasal trauma were included in this retrospective study. Two readers, a staff radiologist and a second-year resident, independently assessed the results of the imaging studies. Of the 108 patients, the presence of a nasal bone fracture was confirmed in 88 (81.5%) patients. The number of non-depressed fractures was higher than the number of depressed fractures. In nine (10.2%) patients, nasal bone fractures were only identified on conventional radiography, including three depressed and six non-depressed fractures. CT was more accurate as compared to conventional radiography for the identification of nasal bone fractures as determined by both readers (P <0.05), all diagnostic indices of an experienced radiologist were similar to or higher than those of a trainee, and κ statistics showed moderate agreement between the two diagnostic tools for both readers. There was no statistical difference in the assessment of interobserver reliability for both imaging modalities in the identification of nasal bone fractures. For the identification of nasal bone fractures, CT was significantly superior to conventional radiography. Although a staff radiologist showed better values in the identification of nasal bone fracture and differentiation between depressed and non-depressed fractures than a trainee, there was no statistically significant difference in the interpretation of conventional radiography and CT between a radiologist and a trainee

  13. Industrial Radiography Safety in Australia

    International Nuclear Information System (INIS)

    Hockings, Colin

    2006-01-01

    cumbersome and often exceeds the prescribed OH and S single person lifting limits. The role of industrial radiography has expanded to inspect not only welds and castings, so that it now includes inspection of assembled and processed goods ranging from automotive air-bags to canned food. It is also used in security systems at airports and other facilities. Almost all these applications use cabinet systems which are rarely the subject of serious radiation incidents or accidents. Gamma ray inspection no longer uses radium. The most common radio-isotopes in use now are Cobalt 60 and Iridium 192. Their freedom from the need for an electrical power supply; their high radiation energy and the ability to place a source in positions of limited physical access, ensures the ongoing attraction of the method. The useful activity ranges of typical sources vary according to their application and the effect on total inspection costs. Common source activities in Australia range between 185 and 370 GBq for Cobalt 60; and between 1500 and 3700 GBq for Iridium 192. Outside Australia however there are recent reports of routine industrial radiography using more than 5500 GBq of Iridium 192. Thus it can be appreciated that any radiation accidents involving these high activity sources have the potential for significant radiation doses. Personal Dose Data: ARPANSA and its predecessor, the Australian Radiation Laboratory, has been providing a personal radiation monitoring service for some time, and releases a summary report every few years (ARPANSA/TR 139, ARL/TR 121, ARL/TR 107). The selected data shown in Table 2 indicate a downward trend in occupational doses received by industrial radiographers working in open site situations, which are potentially the most hazardous. This trend is encouraging, especially when the number of industrial radiographers is increasing. A comparison of the ARPANSA data indicate that whilst the average Australian industrial radiographer's annual dose is higher than the

  14. Ultrasonography of the metacarpophalangeal and proximal interphalangeal joints in rheumatoid arthritis: a comparison with magnetic resonance imaging, conventional radiography and clinical examination

    DEFF Research Database (Denmark)

    Szkudlarek, Marcin; Klarlund, Mette; Narvestad, E.

    2006-01-01

    ultrasonography can provide information on signs of inflammation and destruction in RA finger joints that are not available with conventional radiography and clinical examination, and comparable to the information provided by magnetic resonance imaging (MRI). The second to fifth metacarpophalangeal and proximal...... interphalangeal joints of 40 RA patients and 20 control persons were assessed with ultrasonography, clinical examination, radiography and MRI. With MRI as the reference method, the sensitivity, specificity and accuracy of ultrasonography in detecting bone erosions in the finger joints were 0.59, 0.98 and 0...

  15. Proton radiotherapy for chest wall and regional lymphatic radiation; dose comparisons and treatment delivery

    International Nuclear Information System (INIS)

    MacDonald, Shannon M; Jimenez, Rachel; Paetzold, Peter; Adams, Judith; Beatty, Jonathan; DeLaney, Thomas F; Kooy, Hanne; Taghian, Alphonse G; Lu, Hsiao-Ming

    2013-01-01

    The delivery of post-mastectomy radiation therapy (PMRT) can be challenging for patients with left sided breast cancer that have undergone mastectomy. This study investigates the use of protons for PMRT in selected patients with unfavorable cardiac anatomy. We also report the first clinical application of protons for these patients. Eleven patients were planned with protons, partially wide tangent photon fields (PWTF), and photon/electron (P/E) fields. Plans were generated with the goal of achieving 95% coverage of target volumes while maximally sparing cardiac and pulmonary structures. In addition, we report on two patients with unfavorable cardiac anatomy and IMN involvement that were treated with a mix of proton and standard radiation. PWTF, P/E, and proton plans were generated and compared. Reasonable target volume coverage was achieved with PWTF and P/E fields, but proton therapy achieved superior coverage with a more homogeneous plan. Substantial cardiac and pulmonary sparing was achieved with proton therapy as compared to PWTF and P/E. In the two clinical cases, the delivery of proton radiation with a 7.2 to 9 Gy photon and electron component was feasible and well tolerated. Akimbo positioning was necessary for gantry clearance for one patient; the other was treated on a breast board with standard positioning (arms above her head). LAO field arrangement was used for both patients. Erythema and fatigue were the only noted side effects. Proton RT enables delivery of radiation to the chest wall and regional lymphatics, including the IMN, without compromise of coverage and with improved sparing of surrounding normal structures. This treatment is feasible, however, optimal patient set up may vary and field size is limited without multiple fields/matching

  16. SU-F-T-198: Dosimetric Comparison of Carbon and Proton Radiotherapy for Recurrent Nasopharynx Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Y; Zhao, J; Wang, W; Lin, L; Liu, X; Shahnazi, K [Shanghai Proton and Heavy Ion Center, Shanghai (China)

    2016-06-15

    Purpose: Various radiotherapy planning methods for locally recurrent nasopharynx carcinoma (R-NPC) have been proposed. The purpose of this study was to compare carbon and proton therapy for the treatment of R-NPC in terms of dose coverage for target volume and sparing for organs at risk (OARs). Methods: Six patients who were suffering from R-NPC and treated using carbon therapy were selected for this study. Treatment plans with a total dose of 57.5Gy (RBE) in 23 fractions were made using SIEMENS Syngo V11. An intensity-modulated radiotherapy optimization method was chosen for carbon plans (IMCT) while for proton plans both intensity-modulated radiotherapy (IMPT) and single beam optimization (proton-SBO) methods were chosen. Dose distributions, dose volume parameters, and selected dosimetric indices for target volumes and OARs were compared for all treatment plans. Results: All plans provided comparable PTV coverage. The volume covered by 95% of the prescribed dose was comparable for all three plans. The average values were 96.11%, 96.24% and 96.11% for IMCT, IMPT, and proton-SBO respectively. A significant reduction of the 80% and 50% dose volumes were observed for the IMCT plans compared to the IMPT and proton-SBO plans. Critical organs lateral to the target such as brain stem and spinal cord were better spared by IMPT than by proton-SBO, while IMCT spared those organs best. For organs in the beam path, such as parotid glands, the mean dose results were similar for all three plans. Conclusion: Carbon plans yielded better dose conformity than proton plans. They provided similar or better target coverage while significantly lowering the dose for normal tissues. Dose sparing for critical organs in IMPT plans was better than proton-SBO, however, IMPT is known to be more sensitive to range uncertainties. For proton plans it is essential to find a balance between the two optimization methods.

  17. Neutron radiography, techniques and applications

    International Nuclear Information System (INIS)

    Domanus, J.C.

    1987-10-01

    After describing the principles of the ''in pool'' and ''dry'' installations, techniques used in neutron radiography are reviewed. Use of converter foils with silver halide films for the direct and transfer methods is described. Advantages of the use of nitrocellulose film for radiographying radioactive objects are discussed. Dynamic imaging is shortly reviewed. Standardization in the field of neutron radiography (ASTM and Euratom Neutron Radiography Working Group) is described. The paper reviews main fields of use of neutron radiography. Possibilities of use of neutron radiography at research reactors in various scientific, industrial and other fields are mentioned. Examples are given of application of neutron radiography in industry and the nuclear field. (author)

  18. A Comparison of Angular Values of the Pelvic Limb with Normal and Medial Patellar Luxation Stifles in Chihuahua Dogs Using Radiography and Computed Tomography.

    Science.gov (United States)

    Phetkaew, Thitaporn; Kalpravidh, Marissak; Penchome, Rampaipat; Wangdee, Chalika

    2018-02-01

     This article aimed to determine and compare the angular values of the pelvic limb in normal and medial patellar luxation (MPL) stifles in Chihuahuas using radiography and computed tomographic (CT) scan, to identify the relationship between pelvic limb angles and severity of MPL. In addition, radiographic and CT images were compared to determine the more suitable method of limb deformity assessment.  Sixty hindlimbs of Chihuahuas were divided into normal and grade 1, 2, 3 and 4 MPL groups. The pelvic limb angles in frontal and sagittal planes were evaluated on radiography and CT scan. Femoral and tibial torsion angles (FTA and TTA) were evaluated only by CT scan. All angles were compared among normal and MPL stifles and between radiography and CT scan.  Based on the CT scan, the mechanical lateral distal femoral angle (mLDFA), anatomical caudal proximal femoral angle (aCdPFA), and TTA were related to the severity of MPL. The mLDFA and TTA were significantly increased ( p  Chihuahuas are aLDFA, mLDFA, aCdPFA and TTA. Radiography had some limitations for evaluating pelvic limb angles. The caudocranial radiograph is recommended for the assessment of the distal femoral angles, while the craniocaudal radiograph is for the tibial angles. Schattauer GmbH Stuttgart.

  19. A short comparison of electron and proton transfer processes in biological systems

    International Nuclear Information System (INIS)

    Bertrand, Patrick

    2005-01-01

    The main differences between electron and proton transfers that take place in biological systems are examined. The relation between the distance dependence of the rate constant and the mass of the transferred particle is analyzed in detail. Differences between the two processes have important consequences at the experimental level, which are discussed. The various mechanisms that ensure the coupling between electron and proton transfers are briefly described

  20. Recent developments in radiography

    International Nuclear Information System (INIS)

    Berger, Harold

    1982-01-01

    Advances in radiography are reviewed and eighty-one references are cited to provide additional information. The review includes information on x-ray sources in terms of output, portability and imaging geometry and detectors in terms of films and screens, electrostatic methods, real-time techniques and solid state devices. Inspection methods utilizing radiations other than x-rays, neutrons and charged particles, expand the inspection problems suitable for radiography. Techniques such as tomography, digital radiography and image enhancement are described. Tomography, in particular, provides excellent capability to characterize materials and discontinuities

  1. Transitioning to digital radiography

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, F., E-mail: Francisco.Miranda@pwc.ca [Pratt & Whitney Canada, Longueuil, Quebec (Canada)

    2015-09-15

    This article provides insight on the technical and business considerations necessary to implement or to transition to digital radiography Continued refinements in digital radiography technology have resulted in significant improvements in image quality and detectability of indications. These improvements have resulted in the acceptance of the technology by users and aerospace primes for final product inspection and disposition. Digital radiography has also been identified as an interesting cost reduction initiative with the potential of providing gains in productivity through increased throughput and decreased inspection lead-times and resulting costs. (author)

  2. Direct Comparison of Biologically Optimized Spread-out Bragg Peaks for Protons and Carbon Ions

    International Nuclear Information System (INIS)

    Wilkens, Jan J.; Oelfke, Uwe

    2008-01-01

    Purpose: In radiotherapy with hadrons, it is anticipated that carbon ions are superior to protons, mainly because of their biological properties: the relative biological effectiveness (RBE) for carbon ions is supposedly higher in the target than in the surrounding normal tissue, leading to a therapeutic advantage over protons. The purpose of this report is to investigate this effect by using biological model calculations. Methods and Materials: We compared spread-out Bragg peaks for protons and carbon ions by using physical and biological optimization. The RBE for protons and carbon ions was calculated according to published biological models. These models predict increased RBE values in regions of high linear energy transfer (LET) and an inverse dependency of the RBE on dose. Results: For pure physical optimization, protons yield a better dose distribution along the central axis. In biologically optimized plans, RBE variations for protons were relatively small. For carbon ions, high RBE values were found in the high-LET target region, as well as in the low-dose region outside the target. This means that the LET dependency and dose dependency of the RBE can cancel each other. We show this for radioresistant tissues treated with two opposing beams, for which the predicted carbon RBE within the target volume was lower than outside. Conclusions: For tissue parameters used in this study, the model used does not predict a biologic advantage of carbon ions. More reliable model parameters and clinical trials are necessary to explore the true potential of radiotherapy with carbon ions

  3. Qualitative discussion of quantitative radiography

    International Nuclear Information System (INIS)

    Berger, H.; Motz, J.W.

    1975-01-01

    Since radiography yields an image that can be easily related to the tested object, it is superior to many nondestructive testing techniques in revealing the size, shape, and location of certain types of discontinuities. The discussion is limited to a description of the radiographic process, examination of some of the quantitative aspects of radiography, and an outline of some of the new ideas emerging in radiography. The advantages of monoenergetic x-ray radiography and neutron radiography are noted

  4. Diagnostic accuracy of cone-beam CT in the assessment of mandibular invasion of lower gingival carcinoma: Comparison with conventional panoramic radiography

    International Nuclear Information System (INIS)

    Momin, Mohammad A.; Okochi, Kiyoshi; Watanabe, Hiroshi; Imaizumi, Akiko; Omura, Ken; Amagasa, Teruo; Okada, Norihiko; Ohbayashi, Naoto; Kurabayashi, Tohru

    2009-01-01

    Purpose: To evaluate the diagnostic accuracy of cone-beam CT in assessing mandibular invasion by lower gingival carcinoma and compare it with that of panoramic radiography. Patients and methods: Fifty patients with squamous cell carcinoma of the lower gingiva who were examined by both panoramic radiography and cone-beam CT before surgery were included in this study. Five radiologists used a 6-point rating scale to independently evaluate cone-beam CT and panoramic images for the presence or absence of alveolar bone and mandibular canal involvement by tumor. Using the histopathogical findings as the gold standard, we calculated and compared the area under the receiver operating characteristic curve (Az value) and the sensitivity and specificity of the two imaging modalities. Results: In evaluations of both alveolar bone and mandibular canal involvement, the mean Az value for cone-beam CT (0.918 and 0.977, respectively) was significantly higher than that for panoramic radiography (0.793 and 0.872, respectively). The mean sensitivity for cone-beam CT (89% and 99%, respectively) was significantly higher than that for panoramic radiography (73% and 56%, respectively). There was no significant difference in the mean specificity. While cone-beam CT could provide high-resolution three-dimensional images, the image quality around the alveolar crest was often hampered by severe dental artifacts and image noise, resulting in difficulties in detecting subtle alveolar invasion. Conclusion: Cone-beam CT was significantly superior to panoramic radiography in evaluating mandibular invasion by lower gingival carcinoma. Its diagnostic value in detecting subtle alveolar invasion, however, may be limited by severe dental artifacts and image noise.

  5. Neutron radiography in metallurgy

    International Nuclear Information System (INIS)

    Rant, J.; Ilic, R.

    1977-01-01

    The review surveys microneutronographic and neutron-induced autoradiographic techniques and their applications in metallurgy. A brief survey of applications of neutron radiography as a method of non-destructive testing to some macroscopic problems in metallurgy is included. (author)

  6. High energy neutron radiography

    International Nuclear Information System (INIS)

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

    1996-01-01

    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

  7. Collaboration in radiography: A bibliometric analysis

    International Nuclear Information System (INIS)

    Snaith, Beverly

    2012-01-01

    Introduction: Increasing research activity is an aim of the radiography profession, but there is a lack of knowledge of how this can be achieved. Collaboration between clinical and academic centres as well as between individuals has increased productivity in other professions and has been suggested as a strategy for radiography. This bibliometric study maps the current contribution to the radiography evidence base through a single journal. Method: All articles published in Radiography from 1997 to 2011 were reviewed to identify collaboration trends together with article type and subject. Analysis also enabled comparison of research and publication patterns. Results: 706 articles were published by 1205 individual authors. 63.0% were written by UK based authors, although this varied over time. Over 80% of authors published only single article. Two thirds of articles were collaborative with an increase in clinical-academic co-authorship over the 15 years of the study. Although the majority of articles were diagnostic imaging based, the pattern mirrors the UK workforce profile. Clinicians, including clinical-academic co-authors, tend to write about clinical practice and roles, whereas academics write about a broader range of topics. Conclusions: There has been a growth in research and scholarship within the UK radiography journal and both clinical and academic radiographers are contributing to the evidence base through increased collaboration.

  8. Comparison of surface doses from spot scanning and passively scattered proton therapy beams

    International Nuclear Information System (INIS)

    Arjomandy, Bijan; Sahoo, Narayan; Gillin, Michael; Cox, James; Lee, Andrew

    2009-01-01

    Proton therapy for the treatment of cancer is delivered using either passively scattered or scanning beams. Each technique delivers a different amount of dose to the skin, because of the specific feature of their delivery system. The amount of dose delivered to the skin can play an important role in choosing the delivery technique for a specific site. To assess the differences in skin doses, we measured the surface doses associated with these two techniques. For the purpose of this investigation, the surface doses in a phantom were measured for ten prostate treatment fields planned with passively scattered proton beams and ten patients planned with spot scanning proton beams. The measured doses were compared to evaluate the differences in the amount of skin dose delivered by using these techniques. The results indicate that, on average, the patients treated with spot scanning proton beams received lower skin doses by an amount of 11.8% ± 0.3% than did the patients treated with passively scattered proton beams. That difference could amount to 4 CGE per field for a prescribed dose of 76 CGE in 38 fractions treated with two equally weighted parallel opposed fields. (note)

  9. Efficacy of daily bedside chest radiography as visualized by digital luminescence radiography

    International Nuclear Information System (INIS)

    Kirchner, J.; Stueckle, C.A.; Schilling, E.M.; Peters, J.

    2001-01-01

    To determine the diagnostic impact of daily bedside chest radiography in comparison with digital luminescence technique (DLR; storage phosphor radiography) and conventional film screen radiography, a prospective randomized study was completed in 210 mechanically ventilated patients with a total of 420 analysed radiographs. The patients were allocated to two groups: 150 patients underwent DLR, and 60 patients underwent conventional film screen radiography. Radiological analysis was performed consensually and therapeutic efficacy was assessed by the clinicians. There was no statistical significant difference between the frequency of abnormal findings seen on DLR and conventional film screen radiography. In total, 448 abnormal findings were present in 249 of 300 DLR and 97 of 120 conventional film screen radiographs. The most common findings were signs of overhydration (41 %), pleural effusion (31%), partial collapse of the lung (11%) and pneumothorax (2%). One hundred and twenty-three of 448 (27%) of these abnormal findings were thought to have a considerable impact on patient management. The high rate of abnormal findings with significant impact on patient management suggests that the use of daily bedside chest radiography may be reasonable. Copyright (2001) Blackwell Science Pty Ltd

  10. Digital chest radiography with an amorphous silicon flat-panel-detector versus a storage-phosphor system: comparison of soft-copy images

    International Nuclear Information System (INIS)

    Lee, Hyun Ju; Im, Jung Gi; Goo, Jin Mo; Lee, Chang Hyun

    2006-01-01

    We compared the soft-copy images produced by an amorphous silicon flat-panel-detector system with the images produced by a storage-phosphor radiography system for their ability to visualize anatomic regions of the chest. Two chest radiologists independently analyzed 234 posteroanterior chest radiographs obtained from 78 patients on high-resolution liquid crystal display monitors (2560 x 2048 x 8 bits). In each patient, one radiograph was obtained with a storage-phosphor system, and two radiographs were obtained via amorphous silicon flat-panel-detector radiography with and without spatial frequency filtering. After randomizing the 234 images, the interpreters rated the visibility and radiographic quality of 11 different anatomic regions. Each image was ranked on a five-point scale (1 = not visualized, 2 = poor visualization, 3 = fair visualization, 4 = good visualization, and 5 = excellent visualization). The statistical difference between each system was determined using the Wilcoxon's signed rank test. The visibility of three anatomic regions (hilum, heart border and ribs), as determined by the chest radiologist with 14 years experience (ρ < 0.05) and the visibility of the thoracic spine, as determined by the chest radiologist with 8 years experience (ρ = 0.036), on the amorphous silicon flat-panel-detector radiography prior to spatial frequency filtering were significantly superior to that on the storage-phosphor radiography. The visibility of 11 anatomic regions, as determined by the chest radiologist with 14 years experience (ρ < 0.0001) and the visibility of five anatomic regions (unobscured lung, rib, proximal airway, thoracic spine and overall appearance), as determined by the chest radiologist with 8 years experience (ρ < 0.05), on the amorphous silicon flat-panel-detector radiography after spatial frequency filtering were significantly superior to that on the storage-phosphor radiography. The amorphous silicon flat-panel-detector system depicted the

  11. Opportunities for TRIGA reactors in neutron radiography

    International Nuclear Information System (INIS)

    Barton, John P.

    1978-01-01

    In this country the two most recent installations of TRIGA reactors have both been for neutron radiography, one at HEDL and the other at ANL. Meanwhile, a major portion of the commercial neutron radiography is performed on a TRIGA fueled reactor at Aerotest. Each of these installations has different primary objectives and some comparative observations can be drawn. Another interesting comparison is between the TRIGA reactors for neutron radiography and other small reactors that are being installed for this purpose such as the MIRENE slow pulse reactors in France, a U-233 fueled reactor for neutron radiography in India and the L88 solution reactor in Denmark. At Monsanto Laboratory, in Ohio, a subcritical reactor based on MTR-type fuel has recently been purchased for neutron radiography. Such systems, when driven by a Van de Graaff neutron source, will be compared with the standard TRIGA reactor. Future demands on TRIGA or competitive systems for neutron radiography are likely to include the pulsing capability of the reactor, and also the extraction of cold neutron beams and resonance energy beams. Experiments recently performed on the Oregon State TRIGA Reactor provide information in each of these categories. A point of particular current concern is a comparison made between the resonance energy beam intensity extracted from the edge of the TRIGA core and from a slot which penetrated to the center of the TREAT reactor. These results indicate that by using such slots on a TRIGA, resonance energy intensities could be extracted that are much higher than previously predicted. (author)

  12. A system for fast neutron radiography

    International Nuclear Information System (INIS)

    Klann, R.T.

    1996-01-01

    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 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 7 to 3.8x10 8 n/cm 2 depending on the type of screen and film

  13. submitter Variable RBE in proton therapy: comparison of different model predictions and their influence on clinical-like scenarios

    CERN Document Server

    Giovannini, Giulia; Cabal, Gonzalo; Bauer, Julia; Tessonnier, Thomas; Frey, Kathrin; Debus, Jürgen; Mairani, Andrea; Parodi, Katia

    2016-01-01

    Background: In proton radiation therapy a constant relative biological effectiveness (RBE) of 1.1 is usually assumed. However, biological experiments have evidenced RBE dependencies on dose level, proton linear energy transfer (LET) and tissue type. This work compares the predictions of three of the main radio-biological models proposed in the literature by Carabe-Fernandez, Wedenberg, Scholz and coworkers. Methods: Using the chosen models, a spread-out Bragg peak (SOBP) as well as two exemplary clinical cases (single field and two fields) for cranial proton irradiation, all delivered with state-of-the-art pencil-beam scanning, have been analyzed in terms of absorbed dose, dose-averaged LET $(LET_D)$, RBE-weighted dose $(D_{RBE})$ and biological range shift distributions. Results: In the systematic comparison of RBE predictions by the three models we could show different levels of agreement depending on $(α/β) x$ and LET values. The SOBP study emphasizes the variation of LET D and RBE not only as a functi...

  14. Proton or photon irradiation for hemangiomas of the choroid? A retrospective comparison

    International Nuclear Information System (INIS)

    Hoecht, Stefan; Wachtlin, Joachim; Bechrakis, Nikolaos E.; Schaefer, Christiane; Heufelder, Jens; Cordini, Dino; Kluge, Heinz; Foerster, Michael; Hinkelbein, Wolfgang

    2006-01-01

    Purpose: The aim of this study was to compare, on a retrospective basis, the results of therapy in patients with uveal hemangioma treated with photon or proton irradiation at a single center. Methods and Materials: From 1993 to 2002 a total of 44 patients were treated. Until 1998 radiotherapy was given with 6 MV photons in standard fractionation of 2.0 Gy 5 times per week. In 1998 proton therapy became available and was used since then. A dose of 20 to 22.5 Cobalt Gray Equivalent (CGE) 68 MeV protons was given on 4 consecutive days. Progressive symptoms or deterioration of vision were the indications for therapy. Results: Of the 44 patients treated, 36 had circumscribed choroidal hemangiomas and 8 had diffuse choroidal hemangiomas (DCH) and Sturge-Weber syndrome. Of the patients, 19 were treated with photons with a total dose in the range of 16 to 30 Gy. A total of 25 patients were irradiated with protons. All patients with DCH but 1 were treated with photons. Stabilization of visual acuity was achieved in 93.2% of all patients. Tumor thickness decreased in 95.4% and retinal detachment resolved in 92.9%. Late effects, although generally mild or moderate, were frequently detected. In all, 40.9% showed radiation-induced optic neuropathy, maximum Grade I. Retinopathy was found in 29.5% of cases, but only 1 patient experienced more than Grade II severity. Retinopathy and radiation-induced optic neuropathy were reversible in some of the patients and in some resolved completely. No differences could be detected between patients with circumscribed choroidal hemangiomas treated with protons and photons. Treatment was less effective in DCH patients (75%). Conclusions: Radiotherapy is effective in treating choroidal hemangiomas with respect to visual acuity and tumor thickness but a benefit of proton therapy could not be detected. Side effects are moderate but careful monitoring for side effects should be part of the follow-up procedures

  15. Comparison of multiplicity distributions to the negative binomial distribution in muon-proton scattering

    International Nuclear Information System (INIS)

    Arneodo, M.; Ferrero, M.I.; Peroni, C.; Bee, C.P.; Bird, I.; Coughlan, J.; Sloan, T.; Braun, H.; Brueck, H.; Drees, J.; Edwards, A.; Krueger, J.; Montgomery, H.E.; Peschel, H.; Pietrzyk, U.; Poetsch, M.; Schneider, A.; Dreyer, T.; Ernst, T.; Haas, J.; Kabuss, E.M.; Landgraf, U.; Mohr, W.; Rith, K.; Schlagboehmer, A.; Schroeder, T.; Stier, H.E.; Wallucks, W.

    1987-01-01

    The multiplicity distributions of charged hadrons produced in the deep inelastic muon-proton scattering at 280 GeV are analysed in various rapidity intervals, as a function of the total hadronic centre of mass energy W ranging from 4-20 GeV. Multiplicity distributions for the backward and forward hemispheres are also analysed separately. The data can be well parameterized by binomial distributions, extending their range of applicability to the case of lepton-proton scattering. The energy and the rapidity dependence of the parameters is presented and a smooth transition from the binomial distribution via Poissonian to the ordinary binomial is observed. (orig.)

  16. Reactivation of Latent Epstein-Barr Virus; A Comparison After Gamma Rays and Proton Treatment

    Science.gov (United States)

    Mehta, Satish K.; Plante, Ianik; Bloom, David C.; Stowe, Raymond; Renner, Ashlie; Wu, Honglu; Crucian, Brian; Pierson, Duane L.

    2017-01-01

    Among different unique stressors astronauts are exposed to during spaceflight, cosmic radiation constitutes an important one that leads to various health effects. In particular, space radiation may contribute to decreased immunity, which has been observed in astronauts during short and long duration missions, as evidenced by several changes in cellular immunity and plasma cytokines levels. Reactivation of latent herpes viruses, either directly from radiation or resulting from perturbation in the immune system, is also observed in astronauts. While EBV is one of the eight human herpes viruses known to infect more than 90% human adults and stays latent for the life of the host without normally causing adverse effects of reactivation, increased reactivation in astronauts is well-documented, though the mechanism of this increase is not understood. In this work, we have studied the effect of two different types of radiations, Cs-137 gamma and 150-MeV proton on the reactivation rates of the Epstein - Barr virus (EBV) in vitro in EBV latent cell lines at doses of 0.1, 0.5, 1.0 and 2.0 Gy. While we find that both types of radiations reactivated latent EBV in vitro, we observe that at equivalent doses, early response is stronger for protons but with time, the reactivation induced by gamma rays is more persistent. These differences between the protons and gamma rays curves in latent virus reactivation challenge the common paradigm that protons and gamma rays have similar biological effects.

  17. Comparison of the secondary electrons produced by proton and electron beams in water

    Energy Technology Data Exchange (ETDEWEB)

    Kia, Mohammad Reza, E-mail: m-r-kia@aut.ac.ir; Noshad, Houshyar [Department of Energy Engineering and Physics, Amirkabir University of Technology (Tehran Polytechnic), P.O. Box 15875-4413, Hafez Avenue, Tehran (Iran, Islamic Republic of)

    2016-05-15

    The secondary electrons produced in water by electron and proton beams are compared with each other. The total ionization cross section (TICS) for an electron impact in water is obtained by using the binary-encounter-Bethe model. Hence, an empirical equation based on two adjustable fitting parameters is presented to determine the TICS for proton impact in media. In order to calculate the projectile trajectory, a set of stochastic differential equations based on the inelastic collision, elastic scattering, and bremsstrahlung emission are used. In accordance with the projectile trajectory, the depth dose deposition, electron energy loss distribution in a certain depth, and secondary electrons produced in water are calculated. The obtained results for the depth dose deposition and energy loss distribution in certain depth for electron and proton beams with various incident energies in media are in excellent agreement with the reported experimental data. The difference between the profiles for the depth dose deposition and production of secondary electrons for a proton beam can be ignored approximately. But, these profiles for an electron beam are completely different due to the effect of elastic scattering on electron trajectory.

  18. A dosimetric comparison of proton and photon therapy in unresectable cancers of the head of pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Reid F.; Zhai, Huifang; Both, Stefan; Metz, James M.; Plastaras, John P.; Ben-Josef, Edgar, E-mail: Edgar.Ben-Josef@uphs.upenn.edu [University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Mayekar, Sonal U. [Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Apisarnthanarax, Smith [University of Washington, Seattle, Washington 98109 (United States)

    2014-08-15

    Purpose: Uncontrolled local growth is the cause of death in ∼30% of patients with unresectable pancreatic cancers. The addition of standard-dose radiotherapy to gemcitabine has been shown to confer a modest survival benefit in this population. Radiation dose escalation with three-dimensional planning is not feasible, but high-dose intensity-modulated radiation therapy (IMRT) has been shown to improve local control. Still, dose-escalation remains limited by gastrointestinal toxicity. In this study, the authors investigate the potential use of double scattering (DS) and pencil beam scanning (PBS) proton therapy in limiting dose to critical organs at risk. Methods: The authors compared DS, PBS, and IMRT plans in 13 patients with unresectable cancer of the pancreatic head, paying particular attention to duodenum, small intestine, stomach, liver, kidney, and cord constraints in addition to target volume coverage. All plans were calculated to 5500 cGy in 25 fractions with equivalent constraints and normalized to prescription dose. All statistics were by two-tailed paired t-test. Results: Both DS and PBS decreased stomach, duodenum, and small bowel dose in low-dose regions compared to IMRT (p < 0.01). However, protons yielded increased doses in the mid to high dose regions (e.g., 23.6–53.8 and 34.9–52.4 Gy for duodenum using DS and PBS, respectively; p < 0.05). Protons also increased generalized equivalent uniform dose to duodenum and stomach, however these differences were small (<5% and 10%, respectively; p < 0.01). Doses to other organs-at-risk were within institutional constraints and placed no obvious limitations on treatment planning. Conclusions: Proton therapy does not appear to reduce OAR volumes receiving high dose. Protons are able to reduce the treated volume receiving low-intermediate doses, however the clinical significance of this remains to be determined in future investigations.

  19. Radiography at CERN

    CERN Multimedia

    HSE Unit

    2014-01-01

    What is industrial radiography? It is a non-destructive method with a wide variety of applications, such as inspecting the quality of a weld. It uses high-energy radioactive sources or an X-ray generator.   Is this inspection technique used at CERN? Yes, it is widely used at CERN by the EN-MME Group, which outsources the work to one or more companies, depending on the workload. Is it possible to carry out radiography anywhere at CERN? Yes, it is possible to carry out radiography in any building/accelerator/experiment area at CERN (including in areas which are not normally subject to radiological hazards). When is radiography carried out? It normally takes place outside of working hours (7 p.m. to 6 a.m.). How will I know if radiography is taking place in my building? If this activity is planned in a CERN building, notices will be affixed to all of its main entrance doors at least 24 hours in advance. What are the risks? There is a risk of exposure to very high levels of radiation, dep...

  20. Comparison of proton therapy techniques for treatment of the whole brain as a component of craniospinal radiation

    International Nuclear Information System (INIS)

    Dinh, Jeffrey; Stoker, Joshua; Georges, Rola H; Sahoo, Narayan; Zhu, X Ronald; Rath, Smruti; Mahajan, Anita; Grosshans, David R

    2013-01-01

    For treatment of the entire cranium using passive scattering proton therapy (PSPT) compensators are often employed in order to reduce lens and cochlear exposure. We sought to assess the advantages and consequences of utilizing compensators for the treatment of the whole brain as a component of craniospinal radiation (CSI) with PSPT. Moreover, we evaluated the potential benefits of spot scanning beam delivery in comparison to PSPT. Planning computed tomography scans for 50 consecutive CSI patients were utilized to generate passive scattering proton therapy treatment plans with and without Lucite compensators (PSW and PSWO respectively). A subset of 10 patients was randomly chosen to generate scanning beam treatment plans for comparison. All plans were generated using an Eclipse treatment planning system and were prescribed to a dose of 36 Gy(RBE), delivered in 20 fractions, to the whole brain PTV. Plans were normalized to ensure equal whole brain target coverage. Dosimetric data was compiled and statistical analyses performed using a two-tailed Student’s t-test with Bonferroni corrections to account for multiple comparisons. Whole brain target coverage was comparable between all methods. However, cribriform plate coverage was superior in PSWO plans in comparison to PSW (V95%; 92.9 ± 14 vs. 97.4 ± 5, p < 0.05). As predicted, PSWO plans had significantly higher lens exposure in comparison to PSW plans (max lens dose Gy(RBE): left; 24.8 ± 0.8 vs. 22.2 ± 0.7, p < 0.05, right; 25.2 ± 0.8 vs. 22.8 ± 0.7, p < 0.05). However, PSW plans demonstrated no significant cochlear sparing vs. PSWO (mean cochlea dose Gy(RBE): 36.4 ± 0.2 vs. 36.7 ± 0.1, p = NS). Moreover, dose homogeneity was inferior in PSW plans in comparison to PSWO plans as reflected by significant alterations in both whole brain and brainstem homogeneity index (HI) and inhomogeneity coefficient (IC). In comparison to both PSPT techniques, multi-field optimized intensity modulated (MFO-IMPT) spot

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... are the limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray ( ... leg (shin), ankle or foot. top of page What are some common uses of the procedure? A ...

  2. Digital radiography in NDT applications

    International Nuclear Information System (INIS)

    Deprins, E.

    2004-01-01

    A lot of film radiography could be replaced by today's technologies in the field of digital radiography. Only few of these applications have indeed replaced film. The choice to go digital depends on cost, quality requirement, workflow and throughput. Digital images offer a lot of advantages in terms of image manipulation and workflow. But despite the many advantages, a lot of considerations are needed before someone can decide to convert his organization from conventional to digital radiography. This paper gives an overview of all different modalities that can be used in digital radiography with today's technologies, together with the experiences of the pioneers of digital radiography. Film Scanning, Computed Radiography and Digital Radiography by using of different kinds of flat panel detectors all have their specific application fields and customers. What is the status of the technology today, which advantages brings digital radiography, and which are the limitations radiographers have to consider when replacing film by digital systems. (author)

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

    International Nuclear Information System (INIS)

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

    2006-01-01

    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. (orig.)

  4. Variable RBE in proton therapy: comparison of different model predictions and their influence on clinical-like scenarios

    International Nuclear Information System (INIS)

    Giovannini, Giulia; Böhlen, Till; Cabal, Gonzalo; Bauer, Julia; Tessonnier, Thomas; Frey, Kathrin; Debus, Jürgen; Mairani, Andrea; Parodi, Katia

    2016-01-01

    In proton radiation therapy a constant relative biological effectiveness (RBE) of 1.1 is usually assumed. However, biological experiments have evidenced RBE dependencies on dose level, proton linear energy transfer (LET) and tissue type. This work compares the predictions of three of the main radio-biological models proposed in the literature by Carabe-Fernandez, Wedenberg, Scholz and coworkers. Using the chosen models, a spread-out Bragg peak (SOBP) as well as two exemplary clinical cases (single field and two fields) for cranial proton irradiation, all delivered with state-of-the-art pencil-beam scanning, have been analyzed in terms of absorbed dose, dose-averaged LET (LET D ), RBE-weighted dose (D RBE ) and biological range shift distributions. In the systematic comparison of RBE predictions by the three models we could show different levels of agreement depending on (α/β) x and LET values. The SOBP study emphasizes the variation of LET D and RBE not only as a function of depth but also of lateral distance from the central beam axis. Application to clinical-like scenario shows consistent discrepancies from the values obtained for a constant RBE of 1.1, when using a variable RBE scheme for proton irradiation in tissues with low (α/β) x , regardless of the model. Biological range shifts of 0.6– 2.4 mm (for high (α/β) x ) and 3.0 – 5.4 mm (for low (α/β) x ) were found from the fall-off analysis of individual profiles of RBE-weighted fraction dose along the beam penetration depth. Although more experimental evidence is needed to validate the accuracy of the investigated models and their input parameters, their consistent trend suggests that their main RBE dependencies (dose, LET and (α/β) x ) should be included in treatment planning systems. In particular, our results suggest that simpler models based on the linear-quadratic formalism and LET D might already be sufficient to reproduce important RBE dependencies for re-evaluation of plans optimized with

  5. Are radiography lecturers, leaders?

    International Nuclear Information System (INIS)

    Hendry, Julie Anne

    2013-01-01

    This review article aims to explore the concept of radiography lecturers acting as leaders to their student followers. Through a brief review of the literature, a definition of leadership is suggested and some leadership theories explored. The path-goal theory, leader–member exchange theory and the contemporary theory of transformational leadership are examined more closely. Links between lecturer-leader behaviour and student motivation and learning are tentatively suggested with transformational leadership appearing to offer the optimal leadership style for lecturers to adopt. The paucity of literature relating directly to radiography is acknowledged and areas for further research are suggested. The article concludes with some of the author's practical ideas for incorporating transformational leadership styles and behaviours into radiography education today

  6. Broadening the radiography spectrum

    International Nuclear Information System (INIS)

    Waswa, L.; Mutwasi, O.; Kioko, J.

    2006-05-01

    The text discuses the mammography in breast screening and evaluation of breast cancer; Small parts ultrasounds at plaza imaging solutions; role of a Radiographer in mammography-new perspective; Medical imaging education in africa; Caring for the paediatric patient as to broaden radiotherapy spectrum; Problems and challenges in care for children undergoing radiotherapy; Paediatric radiotherapy, management and side effects; The principles of pattern recognition of skeletal structures; the place of distance learning education in broadening the radiography spectrum; the curriculum and budgeting image; sonographer's guide; Computed radiography- X-Ray with vision; digital Radiography in Kenya today; Particle Therapy at Ithemba Labs; The role of lung perfusion and ventilation study in the evaluation of the pulmonary embolism and lastly, an overview of Head and neck treatment at Kenyatta National hospital radiotherapy

  7. Spatially coded backscatter radiography

    International Nuclear Information System (INIS)

    Thangavelu, S.; Hussein, E.M.A.

    2007-01-01

    Conventional radiography requires access to two opposite sides of an object, which makes it unsuitable for the inspection of extended and/or thick structures (airframes, bridges, floors etc.). Backscatter imaging can overcome this problem, but the indications obtained are difficult to interpret. This paper applies the coded aperture technique to gamma-ray backscatter-radiography in order to enhance the detectability of flaws. This spatial coding method involves the positioning of a mask with closed and open holes to selectively permit or block the passage of radiation. The obtained coded-aperture indications are then mathematically decoded to detect the presence of anomalies. Indications obtained from Monte Carlo calculations were utilized in this work to simulate radiation scattering measurements. These simulated measurements were used to investigate the applicability of this technique to the detection of flaws by backscatter radiography

  8. Computed radiography in paediatrics

    International Nuclear Information System (INIS)

    Kelly, C.

    1996-01-01

    Computed radiography has also been called storage phosphor technology, digital luminescence radiography and scintillation phosphor technology, since it relies on phosphor imaging plate as an alternative to screen-film. One of the major advantages in the use of computed radiography (CR) is the consistent image quality independence of the radiographer and exposure used. And secondly a marked reduction in the need for repeat films was achieved and thus a decrease in dose to the patient. In some cases, dose was able to be reduced further due to the fact that the plates respond to lower doses and still provide adequate image quality. Digitalising the Cr image allows it to be transmitted to an imaging console. The images can then be stored on optical disc. 7 refs

  9. Real-time radiography

    International Nuclear Information System (INIS)

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

    1981-01-01

    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

  10. SIMPLE for industrial radiography

    International Nuclear Information System (INIS)

    Azhar Azmi; Abd Nassir Ibrahim; Siti Madiha Muhammad Amir; Glam Hadzir Patai Mohamad; Saidi Rajab

    2004-01-01

    The first thing industrial radiographers have to do before commencing radiography works is to determine manually the amount of correct exposure that the film need to be exposed in order to obtain the right density. The amount of exposure depends on many variables such as type of radioisotope, type of film, nature of test-object and its orientation, and specific arrangement related to object location and configuration. In many cases radiography works are rejected because of radiographs fail to meet certain reference criteria as defined in the applicable standard. One of the main reasons of radiograph rejection is due to inadequate exposure received by the films. SIMPLE is a software specially developed to facilitate the calculation of gamma-radiography exposure. By using this software and knowing radiographic parameters to be encountered during the work, it is expected that human error will be minimized, thus enhancing the quality and productivity of NDT jobs. (Author)

  11. Practical radiography. 11. ed.

    International Nuclear Information System (INIS)

    Hoxter, E.A.

    1982-01-01

    After a brief explanation of the basics of electricity, the fundamentals of radiography are dealt with in more detail - the discovery of X-rays, their nature and properties, the production of the X-ray image and ways of improving the image. A chapter is devoted to the important subject of radiation protection. Explanations are given of the use of the Siemens exposure tables, which make it simpler to modify exposures from the values given in the tables. There is also a section on some of the standard radiographic positioning for patients. The most common medical terms used in radiography and fluoroscopy are listed and an Appendix gives details of the major items of Siemens X-ray equipment. There is a list of literature recommended for further study. Theoretical explanations have been kept to a minimum so that information that is important to radiography can be emphasized. (orig./MG)

  12. Radiography of pressure ulcers

    International Nuclear Information System (INIS)

    Borgstroem, P.S.; Ekberg, O.; Lasson, A.

    1988-01-01

    In patients with longstanding and/or deep pressure ulcers radiology is usually consulted. Survey radiography and sinography in 14 patients with pressure ulcers (6 over the tuber ischii and 8 over the femoral trochanter) were evaluated. Osteomyelitic involvement of adjacent bone was revealed in 9 patients on survey radiography. However, it was usually impossible to assess whether or not bony involvement represents healed or active osteomyelitis. Sinography did not contribute to the assessment of whether or not adjacent cortical bone was involved. However, when a fistulation to an adjacent joint was revealed this contributed substantially to the preoperative planning of resection. We therefore recommend that survey radiography and sinography should be included in the evaluation of these patients but that the results from such examinations are critically evaluated. Joint involvement should be taken seriously as progression of septic arthritis usually occurs rapidly. (orig.)

  13. Radiography Capabilities for Matter-Radiation Interactions in Extremes

    Energy Technology Data Exchange (ETDEWEB)

    Walstrom, Peter Lowell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Garnett, Robert William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chapman, Catherine A. B [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Salazar, Harry Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Otoole, Joseph Alfred [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Barber, Ronald L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gomez, Tony Simon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    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.

  14. Comparison of protons, carbon and fullerene impacts on a carbon cylinder

    CERN Document Server

    Webb, R P

    2003-01-01

    The use of protons in radiation treatment has been much studied and is widely used in the treatment of cancer cells. The proton causes damage to the strands of DNA in the cells largely by interaction with the electronic system. The proton interactions largely result in bond breakage in the DNA molecules. Sometimes the resulting damage to the DNA molecule is insufficient to cause both strands of the molecule to be broken and consequently the cell can reproduce despite being irradiated. Heavy ion therapy using carbon ions has been used to try and introduce more damage into the molecule structure, ensuring that both strands of the DNA are broken and hence preventing the cell from replicating. However, it seems that even the use of ions as heavy as carbon still result in DNA that is not fully damaged. The simulations reported here form a preliminary investigation on the possible use of a molecular species to deliver multiple impacting particles to the molecular structure thereby increasing the energy density of t...

  15. Comparison of proton microbeam and gamma irradiation for the radiation hardness testing of silicon PIN diodes

    Science.gov (United States)

    Jakšić, M.; Grilj, V.; Skukan, N.; Majer, M.; Jung, H. K.; Kim, J. Y.; Lee, N. H.

    2013-09-01

    Simple and cost-effective solutions using Si PIN diodes as detectors are presently utilized in various radiation-related applications in which excessive exposure to radiation degrades their charge transport properties. One of the conventional methods for the radiation hardness testing of such devices is time-consuming irradiation with electron beam or gamma-ray irradiation facilities, high-energy proton accelerators, or with neutrons from research reactors. Recently, for the purpose of radiation hardness testing, a much faster nuclear microprobe based approach utilizing proton irradiation has been developed. To compare the two different irradiation techniques, silicon PIN diodes have been irradiated with a Co-60 gamma radiation source and with a 6 MeV proton microbeam. The signal degradation in the silicon PIN diodes for both irradiation conditions has been probed by the IBIC (ion beam induced charge) technique, which can precisely monitor changes in charge collection efficiency. The results presented are reviewed on the basis of displacement damage calculations and NIEL (non-ionizing energy loss) concept.

  16. Proton radiation therapy for retinoblastoma: Comparison of various intraocular tumor locations and beam arrangements

    International Nuclear Information System (INIS)

    Krengli, Marco; Hug, Eugen B.; Adams, Judy A.; Smith, Alfred R.; Tarbell, Nancy J.; Munzenrider, John E.

    2005-01-01

    Purpose: To study the optimization of proton beam arrangements for various intraocular tumor locations; and to correlate isodose distributions with various target and nontarget structures. Methods and materials: We considered posterior-central, nasal, and temporal tumor locations, with straight, intrarotated, or extrarotated eye positions. Doses of 46 cobalt grey equivalent (CGE) to gross tumor volume (GTV) and 40 CGE to clinical target volume (CTV) (2 CGE per fraction) were assumed. Using three-dimensional planning, we compared isodose distributions for lateral, anterolateral oblique, and anteromedial oblique beams and dose-volume histograms of CTVs, GTVs, lens, lacrimal gland, bony orbit, and soft tissues. Results: All beam arrangements fully covered GTVs and CTVs with optimal lens sparing. Only 15% of orbital bone received doses ≥20 CGE with a lateral beam, with 20-26 CGE delivered to two of three growth centers. The anterolateral oblique approach with an intrarotated eye resulted in additional reduction of bony volume and exposure of only one growth center. No appreciable dose was delivered to the contralateral eye, brain tissue, or pituitary gland. Conclusions: Proton therapy achieved homogeneous target coverage with true lens sparing. Doses to orbit structures, including bony growth centers, were minimized with different beam arrangements and eye positions. Proton therapy could reduce the risks of second malignancy and cosmetic and functional sequelae

  17. Compton radiography, 4. Magnification compton radiography

    Energy Technology Data Exchange (ETDEWEB)

    Okuyama, S; Sera, K; Shishido, F; Fukuda, H [Tohoku Univ., Sendai (Japan). Research Inst. for Tuberculosis and Cancer; Mishina, H

    1978-03-01

    Compton radiography permits an acquisition of direct magnification Compton radiograms by use of a pinhole collimator, rendering it feasible to overcome the resolution of the scinticamera being employed. An improvement of resolution was attained from 7 mm to 1 mm separation. Usefulness of its clinical application can be seen in orientation of puncture and biopsy in deep structures and detection of various foreign bodies penetrated by blasts and so on under the ''magnification Compton fluoroscopy'' which can be developed on this principle in the near future.

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive medical ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small dose ... limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  1. Bone X-Ray (Radiography)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  3. Comparison of proton therapy techniques for treatment of the whole brain as a component of craniospinal radiation.

    Science.gov (United States)

    Dinh, Jeffrey; Stoker, Joshua; Georges, Rola H; Sahoo, Narayan; Zhu, X Ronald; Rath, Smruti; Mahajan, Anita; Grosshans, David R

    2013-12-17

    For treatment of the entire cranium using passive scattering proton therapy (PSPT) compensators are often employed in order to reduce lens and cochlear exposure. We sought to assess the advantages and consequences of utilizing compensators for the treatment of the whole brain as a component of craniospinal radiation (CSI) with PSPT. Moreover, we evaluated the potential benefits of spot scanning beam delivery in comparison to PSPT. Planning computed tomography scans for 50 consecutive CSI patients were utilized to generate passive scattering proton therapy treatment plans with and without Lucite compensators (PSW and PSWO respectively). A subset of 10 patients was randomly chosen to generate scanning beam treatment plans for comparison. All plans were generated using an Eclipse treatment planning system and were prescribed to a dose of 36 Gy(RBE), delivered in 20 fractions, to the whole brain PTV. Plans were normalized to ensure equal whole brain target coverage. Dosimetric data was compiled and statistical analyses performed using a two-tailed Student's t-test with Bonferroni corrections to account for multiple comparisons. Whole brain target coverage was comparable between all methods. However, cribriform plate coverage was superior in PSWO plans in comparison to PSW (V95%; 92.9 ± 14 vs. 97.4 ± 5, p left; 24.8 ± 0.8 vs. 22.2 ± 0.7, p right; 25.2 ± 0.8 vs. 22.8 ± 0.7, p vs. PSWO (mean cochlea dose Gy(RBE): 36.4 ± 0.2 vs. 36.7 ± 0.1, p = NS). Moreover, dose homogeneity was inferior in PSW plans in comparison to PSWO plans as reflected by significant alterations in both whole brain and brainstem homogeneity index (HI) and inhomogeneity coefficient (IC). In comparison to both PSPT techniques, multi-field optimized intensity modulated (MFO-IMPT) spot scanning treatment plans displayed superior sparing of both lens and cochlea (max lens: 12.5 ± 0.6 and 12.9 ± 0.7 right and left respectively; mean cochlea 28.6

  4. Comparative study between computed radiography and conventional radiography

    International Nuclear Information System (INIS)

    Noorhazleena Azaman; Khairul Anuar Mohd Salleh; Sapizah Rahim; Shaharudin Sayuti; Arshad Yassin; Abdul Razak Hamzah

    2010-01-01

    In Industrial Radiography, there are many criteria that need to be considered based on established standards to accept or reject the radiographic film. For conventional radiography, we need to consider the optical density by using the densitometer when viewing the film on the viewer. But in the computed radiography (CR) we need to evaluate and performed the analysis from the quality of the digital image through grey value. There are many factors that affected the digital image quality. One of the factors which are affected to the digital image quality in the image processing is grey value that related to the contrast resolution. In this work, we performed grey value study measurement on digital radiography systems and compared it with exposed films in conventional radiography. The test sample is a steel step wedge. We found out the contrast resolution is higher in Computed Radiography compared with Conventional Radiography. (author)

  5. The stationary neutron radiography system

    International Nuclear Information System (INIS)

    Weeks, A.A.; Newell, D.L.; Heidel, C.C.

    1990-01-01

    To provide the high intensity neutron beam and support systems necessary for radiography, the Stationary Neutron Radiography System was constructed at McClellan Air Force Base. The Stationary Neutron Radiography System utilizes a one megawatt TRIGA reactor contained in an Aluminium tank surrounded by eight foot thick concrete walls. There are four neutron beam tubes at inclined angles from the reactor core to separate radiography bays. In three of the bays, robotic systems manipulate aircraft components in the neutron beam, while real-time imaging systems provide images concurrent with the irradiation. Film radiography of smaller components is performed in the remaining bay

  6. Neutron radiography using a transportable superconducting cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Allen, D.A. (School of Physics and Space Research, University of Birmingham, Birmingham, B15 2TT (United Kingdom)); Hawkesworth, M.R. (School of Physics and Space Research, University of Birmingham, Birmingham, B15 2TT (United Kingdom)); Beynon, T.D. (School of Physics and Space Research, University of Birmingham, Birmingham, B15 2TT (United Kingdom)); Green, S. (School of Physics and Space Research, University of Birmingham, Birmingham, B15 2TT (United Kingdom)); Rogers, J.D. (Rolls-Royce, Derby (United Kingdom)); Allen, M.J. (Rolls-Royce, Derby (United Kingdom)); Plummer, H.C. (Rolls-Royce, MatEval, Derby (United Kingdom)); Boulding, N.J. (Oxford Instruments (United Kingdom)); Cox, M. (Oxford Instruments (United Kingdom)); McDougall, I. (Oxford Instruments (United Kingdom))

    1994-12-30

    A thermal neutron radiography system based on a compact 12 MeV superconducting proton cyclotron is described. Neutrons are generated using a thick beryllium target and moderated in high density polyethylene. Monte Carlo computer simulations have been used to model the neutron and photon transport in order to optimise the performance of the system. With proton beam currents in excess of 100 [mu]A, it can provide high thermal neutron fluxes with L/D ratios of between 50 and 300 for various applications. Both film and electronic imaging are used to produce radiographs. The electronic imaging system consists of a [sup 6]Li-loaded ZnS intensifier screen, and a low light CCD or SIT camera. High resolution images can be recorded and computer-controlled data processing, analysis and display are possible. ((orig.))

  7. Two-proton decays from light to heavy nuclei - Comparison of theory and experiment

    International Nuclear Information System (INIS)

    Grigorenko, L. V.; Zhukov, M. V.

    2009-01-01

    Two-proton (2p) radioactivity was predicted by V.I. Goldansky in 1960 [1] as an exclusively quantum-mechanical phenomenon. True three-body decay, in his terms, is a situation where the sequential emission of the particles is energetically prohibited from the ground state of a nucleus and all the final-state fragments are emitted simultaneously. Since the experimental discovery of the 4 6F e two-proton radioactivity in 2002 [2,3], this field has made fast progress. New cases of 2p radioactivity were found for 6 4Z n [4], 1 9M g [5], and, maybe, 4 8N i [6]. The 2p correlations were recently measured for the ground state decays of 4 6F e [7], 1 9M g [5,8], 1 6N e [8], and 6 B e [9]. All these decays exhibit complex correlation patterns. These correlation patterns are well described within the three-cluster theory of two-proton radioactivity (see Ref. [9] and Refs. therein); the example of the 6 B e ground state decay is provided in Fig. 1. The correlations are shown to be sensitive to the details of structure and nuclear interactions. Thus experimental studies of correlations can provide important information about the structure of decaying nuclei. With lifetimes and correlations well described by the theory in a broad range of nuclear masses (6 B e, 1 9M g, and 4 6F e belong to p, s-d, and p-f shells respectively) understanding of the nature of 2p radioactivity is getting now a solid empirical support. This is specially important in the view of astrophysical implementations of the three-body decay theory for the inverse processes of the three-body radiative capture in astrophysics, which seem to be not completely understood so far.(author)

  8. Proton Beam Therapy for Hepatocellular Carcinoma: A Comparison of Three Treatment Protocols

    Energy Technology Data Exchange (ETDEWEB)

    Mizumoto, Masashi; Okumura, Toshiyuki; Hashimoto, Takayuki [Proton Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki (Japan); Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki (Japan); Fukuda, Kuniaki [Department of Gastroenterology, University of Tsukuba, Tsukuba, Ibaraki (Japan); Oshiro, Yoshiko; Fukumitsu, Nobuyoshi [Proton Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki (Japan); Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki (Japan); Abei, Masato [Department of Gastroenterology, University of Tsukuba, Tsukuba, Ibaraki (Japan); Kawaguchi, Atsushi [Biostatistics Center, Kurume University, Fukuoka (Japan); Hayashi, Yasutaka; Ookawa, Ayako; Hashii, Haruko; Kanemoto, Ayae [Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki (Japan); Moritake, Takashi [Proton Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki (Japan); Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki (Japan); Tohno, Eriko [Department of Diagnostic Radiology, University of Tsukuba, Tsukuba, Ibaraki (Japan); Tsuboi, Koji [Proton Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki (Japan); Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki (Japan); Sakae, Takeji [Proton Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki (Japan); Sakurai, Hideyuki, E-mail: hsakurai@pmrc.tsukuba.ac.jp [Proton Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki (Japan); Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki (Japan)

    2011-11-15

    Background: Our previous results for treatment of hepatocellular carcinoma (HCC) with proton beam therapy revealed excellent local control with low toxicity. Three protocols were used to avoid late complications such as gastrointestinal ulceration and bile duct stenosis. In this study, we examined the efficacy of these protocols. Methods and Materials: The subjects were 266 patients (273 HCCs) treated by proton beam therapy at University of Tsukuba between January 2001 and December 2007. Three treatment protocols (A, 66 GyE in 10 fractions; B, 72.6 GyE in 22 fractions; and C, 77 GyE in 35 fractions) were used, depending on the tumor location. Results: Of the 266 patients, 104, 95, and 60 patients were treated with protocols A, B, and C, respectively. Seven patients with double lesions underwent two different protocols. The overall survival rates after 1, 3 and 5 years were 87%, 61%, and 48%, respectively (median survival, 4.2 years). Multivariate analysis showed that better liver function, small clinical target volume, and no prior treatment (outside the irradiated field) were associated with good survival. The local control rates after 1, 3, and 5 years were 98%, 87%, and 81%, respectively. Multivariate analysis did not identify any factors associated with good local control. Conclusions: This study showed that proton beam therapy achieved good local control for HCC using each of three treatment protocols. This suggests that selection of treatment schedules based on tumor location may be used to reduce the risk of late toxicity and maintain good treatment efficacy.

  9. Comparison of pad detectors produced on different silicon materials after irradiation with neutrons, protons and pions

    International Nuclear Information System (INIS)

    Kramberger, G.; Cindro, V.; Dolenc, I.; Mandic, I.; Mikuz, M.; Zavrtanik, M.

    2010-01-01

    A set of 44 pad detectors produced on p- and n-type MCz and Fz wafers was irradiated with 23 GeV protons, 200 MeV pions and reactor neutrons up to the equivalent fluences of Φ eq =3x10 15 cm -2 . The evolution of the full depletion voltage and the leakage current were monitored during short- and long-term annealing. At selected representative annealing steps, charge collection measurements were performed for all samples with LHC speed electronics. Measurements of full depletion voltage, leakage current and charge collection efficiency were compared for different irradiation particles and silicon materials.

  10. Comparison of pad detectors produced on different silicon materials after irradiation with neutrons, protons and pions

    Energy Technology Data Exchange (ETDEWEB)

    Kramberger, G., E-mail: Gregor.Kramberger@ijs.s [Jozef Stefan Institute and Department of Physics, University of Ljubljana, SI-1000 Ljubljana (Slovenia); Cindro, V.; Dolenc, I.; Mandic, I.; Mikuz, M.; Zavrtanik, M. [Jozef Stefan Institute and Department of Physics, University of Ljubljana, SI-1000 Ljubljana (Slovenia)

    2010-01-01

    A set of 44 pad detectors produced on p- and n-type MCz and Fz wafers was irradiated with 23 GeV protons, 200 MeV pions and reactor neutrons up to the equivalent fluences of PHI{sub eq}=3x10{sup 15}cm{sup -2}. The evolution of the full depletion voltage and the leakage current were monitored during short- and long-term annealing. At selected representative annealing steps, charge collection measurements were performed for all samples with LHC speed electronics. Measurements of full depletion voltage, leakage current and charge collection efficiency were compared for different irradiation particles and silicon materials.

  11. Manual on industrial radiography

    International Nuclear Information System (INIS)

    1981-08-01

    This manual is intended as a source of educational material to personnel seeking certification as industrial radiographers, and as a guide and reference text for educational organizations that are providng courses in industrial radiography. It covers the basic principles of x-ray and gamma radiation, radiation safety, films and film processing, welding, casting and forging, aircraft structures and components, radiographic techniques, and records

  12. Compton radiography, 2

    International Nuclear Information System (INIS)

    Okuyama, Shinichi; Sera, Koichiro; Fukuda, Hiroshi; Shishido, Fumio; Mishina, Hitoshi.

    1977-01-01

    Compton radiography, a tomographic technic with Compton-scattered rays of a monochromatic gamma ray beam, was feasible of tomographing a chest phantom. The result suggested that the technic could be extended to imaging of the lung and the surrounding structures of the chest wall, mediastinum and liver in Compton tomographic mode. (auth.)

  13. Neutron radiography in Brazil

    International Nuclear Information System (INIS)

    Rogers, J.D.

    1983-01-01

    Neutron radiography studies being carried out in reactor centres in Brazil are discussed. These research projects are under way using the 5 MW swimming pool reactor at the Institute of Energy and Nuclear Research (IPEN) in Sao Paulo and the Argonaut reactor at the Institute of Nuclear Engineering (IEN) in Rio de Janeiro. (Auth.)

  14. Basic principles of industrial radiography

    International Nuclear Information System (INIS)

    Bestbier, P.

    1983-01-01

    X-ray radiography and gamma radiography are used in industrial radiography. X-rays and gamma rays have the ability to penetrate materials and be absorbed by different densities. This characteristic makes them useful tools in industrial and medical radiography. The sources used for the generation of x-rays, gamma rays and radioisotopes are discussed. Films are one of the recording methods of x-radiography. The article also deals with advantages and disadvantages of radiography. Factors governing radiation exposure includes: the type of radiation source, material to be radiographed, distance, film, and the method for development. International specifications are also responsible for strict control over the standard of workmanship in industrial radiography

  15. Proton microscope design for 9 GeV pRad facility

    International Nuclear Information System (INIS)

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

    2016-01-01

    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.

  16. A review of digital radiography technology for valve inspection

    International Nuclear Information System (INIS)

    Stoev, K.; Guerout, F.M.; Horn, D.

    2008-01-01

    There are thousands of valves in a nuclear power plant (NPP) used for control, safety and checks in various plant systems, so there is a well-identified need for fast and reliable inspection and diagnostics of valves. Digital radiography can provide considerable improvements to the inspection and testing procedures for valves in comparison to classical film radiography. These improvements can lead to significant financial advantages by providing real-time inspection results, significantly reduced inspection and decision-making time, and reduced operational cost. Digital image processing, including digital image enhancement, digital archiving, and digital communication of the images and the results, is also a considerable advantage over classical film radiography technology. Another advantage of digital radiography technology is the improved safety and the reduced environmental impact due to reduced exposure/test times, use of smaller exclusion zones, elimination of chemical processing, and absence of disposable materials. This paper reviews the existing technology and evaluates the potential of digital radiography for inspection and diagnostics of valves. Station needs and requirements are assessed, and the safety, environmental and economical constraints of digital radiography techniques estimated. The advantages and disadvantages of different digital radiography equipment are compared, and their limitations and characteristics studied. (author)

  17. Artifacts in digital radiography

    Energy Technology Data Exchange (ETDEWEB)

    Min, Jung Whan [Dept. of Radiological Technology, Shin Gu University, Sungnam (Korea, Republic of); Kim, Jung Min [Dept. of Radiological Technology, Korea University, Seoul (Korea, Republic of); Jeong, Hoi Woun [Dept. of Radiological Technology, Beakseok Culture University, Cheonan (Korea, Republic of)

    2015-12-15

    Digital Radiography is a big part of diagnostic radiology. Because uncorrected digital radiography image supported false effect of Patient’s health care. We must be manage the correct digital radiography image. Thus, the artifact images can have effect to make a wrong diagnosis. We report types of occurrence by analyzing the artifacts that occurs in digital radiography system. We had collected the artifacts occurred in digital radiography system of general hospital from 2007 to 2014. The collected data had analyzed and then had categorize as the occurred causes. The artifacts could be categorized by hardware artifacts, software artifacts, operating errors, system artifacts, and others. Hardware artifact from a Ghost artifact that is caused by lag effect occurred most frequently. The others cases are the artifacts caused by RF noise and foreign body in equipments. Software artifacts are many different types of reasons. The uncorrected processing artifacts and the image processing error artifacts occurred most frequently. Exposure data recognize (EDR) error artifacts, the processing error of commissural line, and etc., the software artifacts were caused by various reasons. Operating artifacts were caused when the user did not have the full understanding of the digital medical image system. System artifacts had appeared the error due to DICOM header information and the compression algorithm. The obvious artifacts should be re-examined, and it could result in increasing the exposure dose of the patient. The unclear artifact leads to a wrong diagnosis and added examination. The ability to correctly determine artifact are required. We have to reduce the artifact occurrences by understanding its characteristic and providing sustainable education as well as the maintenance of the equipments.

  18. Artifacts in digital radiography

    International Nuclear Information System (INIS)

    Min, Jung Whan; Kim, Jung Min; Jeong, Hoi Woun

    2015-01-01

    Digital Radiography is a big part of diagnostic radiology. Because uncorrected digital radiography image supported false effect of Patient’s health care. We must be manage the correct digital radiography image. Thus, the artifact images can have effect to make a wrong diagnosis. We report types of occurrence by analyzing the artifacts that occurs in digital radiography system. We had collected the artifacts occurred in digital radiography system of general hospital from 2007 to 2014. The collected data had analyzed and then had categorize as the occurred causes. The artifacts could be categorized by hardware artifacts, software artifacts, operating errors, system artifacts, and others. Hardware artifact from a Ghost artifact that is caused by lag effect occurred most frequently. The others cases are the artifacts caused by RF noise and foreign body in equipments. Software artifacts are many different types of reasons. The uncorrected processing artifacts and the image processing error artifacts occurred most frequently. Exposure data recognize (EDR) error artifacts, the processing error of commissural line, and etc., the software artifacts were caused by various reasons. Operating artifacts were caused when the user did not have the full understanding of the digital medical image system. System artifacts had appeared the error due to DICOM header information and the compression algorithm. The obvious artifacts should be re-examined, and it could result in increasing the exposure dose of the patient. The unclear artifact leads to a wrong diagnosis and added examination. The ability to correctly determine artifact are required. We have to reduce the artifact occurrences by understanding its characteristic and providing sustainable education as well as the maintenance of the equipments

  19. Treatment of Non-Small Cell Lung Cancer Patients With Proton Beam-Based Stereotactic Body Radiotherapy: Dosimetric Comparison With Photon Plans Highlights Importance of Range Uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Seco, Joao, E-mail: jseco@partners.org [Department of Radiation Oncology, Harvard Medical School and Massachusetts General Hospital, Boston, MA (United States); Panahandeh, Hamid Reza [Department of Radiation Oncology, Harvard Medical School and Massachusetts General Hospital, Boston, MA (United States); Westover, Kenneth [Department of Radiation Oncology, Harvard Medical School and Massachusetts General Hospital, Boston, MA (United States); Harvard Radiation Oncology Program, Harvard Medical School, Boston, MA (United States); Adams, Judith; Willers, Henning [Department of Radiation Oncology, Harvard Medical School and Massachusetts General Hospital, Boston, MA (United States)

    2012-05-01

    Purpose: Proton beam radiotherapy has been proposed for use in stereotactic body radiotherapy (SBRT) for early-stage non-small-cell lung cancer. In the present study, we sought to analyze how the range uncertainties for protons might affect its therapeutic utility for SBRT. Methods and Materials: Ten patients with early-stage non-small-cell lung cancer received SBRT with two to three proton beams. The patients underwent repeat planning for photon SBRT, and the dose distributions to the normal and tumor tissues were compared with the proton plans. The dosimetric comparisons were performed within an operational definition of high- and low-dose regions representing volumes receiving >50% and <50% of the prescription dose, respectively. Results: In high-dose regions, the average volume receiving {>=}95% of the prescription dose was larger for proton than for photon SBRT (i.e., 46.5 cm{sup 3} vs. 33.5 cm{sup 3}; p = .009, respectively). The corresponding conformity indexes were 2.46 and 1.56. For tumors in close proximity to the chest wall, the chest wall volume receiving {>=}30 Gy was 7 cm{sup 3} larger for protons than for photons (p = .06). In low-dose regions, the lung volume receiving {>=}5 Gy and maximum esophagus dose were smaller for protons than for photons (p = .019 and p < .001, respectively). Conclusions: Protons generate larger high-dose regions than photons because of range uncertainties. This can result in nearby healthy organs (e.g., chest wall) receiving close to the prescription dose, at least when two to three beams are used, such as in our study. Therefore, future research should explore the benefit of using more than three beams to reduce the dose to nearby organs. Additionally, clinical subgroups should be identified that will benefit from proton SBRT.

  20. Z-petawatt driven ion beam radiography development.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Proton-proton bremsstrahlung

    International Nuclear Information System (INIS)

    Fearing, H.W.

    1990-01-01

    We summarize some of the information about the nucleon-nucleon force which has been obtained by comparing recent calculations of proton-proton bremsstrahlung with cross section and analyzing power data from the new TRIUMF bremsstrahlung experiment. Some comments are made as to how these results can be extended to neutron-proton bremsstrahlung. (Author) 17 refs., 6 figs

  2. Evaluation and comparison of New 4DCT based strategies for proton treatment planning for lung tumors

    International Nuclear Information System (INIS)

    Wang, Ning; Patyal, Baldev; Ghebremedhin, Abiel; Bush, David

    2013-01-01

    To evaluate different strategies for proton lung treatment planning based on four-dimensional CT (4DCT) scans. Twelve cases, involving only gross tumor volumes (GTV), were evaluated. Single image sets of (1) maximum intensity projection (MIP3) of end inhale (EI), middle exhale (ME) and end exhale (EE) images; (2) average intensity projection (AVG) of all phase images; and (3) EE images from 4DCT scans were selected as primary images for proton treatment planning. Internal target volumes (ITVs) outlined by a clinician were imported into MIP3, AVG, and EE images as planning targets. Initially, treatment uncertainties were not included in planning. Each plan was imported into phase images of 4DCT scans. Relative volumes of GTVs covered by 95% of prescribed dose and mean ipsilateral lung dose of a phase image obtained by averaging the dose in inspiration and expiration phases were used to evaluate the quality of a plan for a particular case. For comparing different planning strategies, the mean of the averaged relative volumes of GTVs covered by 95% of prescribed dose and its standard deviation for each planning strategy for all cases were used. Then, treatment uncertainties were included in planning. Each plan was recalculated in phase images of 4DCT scans. Same strategies were used for plan evaluation except dose-volume histograms of the planning target volumes (PTVs) instead of GTVs were used and the mean and standard deviation of the relative volumes of PTVs covered by 95% of prescribed dose and the ipsilateral lung dose were used to compare different planning strategies. MIP3 plans without treatment uncertainties yielded 96.7% of the mean relative GTV covered by 95% of prescribed dose (standard deviations of 5.7% for all cases). With treatment uncertainties, MIP3 plans yielded 99.5% of mean relative PTV covered by 95% of prescribed dose (standard deviations of 0.7%). Inclusion of treatment uncertainties improved PTV dose coverage but also increased the ipsilateral

  3. Comparison of Enamel and Stainless Steel Electron Cloud Clearing Electrodes Tested in the CERN Proton Synchrotron

    CERN Document Server

    Caspers, Friedhelm; Mahner, C; Wendel, JC

    2010-01-01

    During the 2007 run with the nominal LHC proton beam, electron cloud has been clearly identified and characterized in the PS using a dedicated setup with shielded button-type pickups. Efficient electron cloud suppression could be achieved with a stainless steel stripline-type electrode biased to negative and positive voltages up to ± 1 kV. For the 2008 run, a second setup was installed in straight section 84 of the PS where the stainless steel was replaced by a stripline composed of an enamel insulator with a resistive coating. In contrast to ordinary stripline electrodes this setup presents a very low beam coupling impedance and could thus be envisaged for long sections of high-intensity machines. Here, we present first comparative measurements with this new type of enamel clearing electrode using the nominal LHC beam with 72 bunches and 25 ns bunch spacing.

  4. Radiography – How do students understand the concept of radiography?

    International Nuclear Information System (INIS)

    Lundgren, S.M.; Lundén, M.; Andersson, B.T.

    2015-01-01

    Background: Radiography as a concept has mainly been associated with the functional role of the radiographer. The concept has been studied from a theoretical point of view. However, there is a lack of a theoretical foundation and research on the actual substance of the term radiography used in education. It is therefore important to undertake an investigation in order to determine how students after three years education understand the subject of radiography. Aim: The aim of this study was to analyse how students in the Swedish radiographers' degree program understand the concept of radiography. Method: A concept analysis was made according to the hybrid model, which combines theoretical, fieldwork and analytical phases. A summative content analysis was used to identify the number and content of statements. The empirical data were collected from questionnaires answered by radiography students at four universities in Sweden. Findings: All radiography students' exemplified radiography with statements related to the practical level although some of them also identified radiography at an abstract level, as a subject within a discipline. The attribute ‘An interdisciplinary area of knowledge’ emerged, which is an attribute on the abstract level. The practical level was described by four attributes: Mastering Medical Imaging’, ‘To accomplish images for diagnosis and interventions’, ‘Creating a caring environment’ and ‘Enabling fruitful encounters’. Conclusion: The hybrid model used was a versatile model of concept development. The results of this study have increased the understanding of what characterizes the concept of radiography in a Swedish context. - Highlights: • This concept analysis of radiography was undertaken according to a hybrid model. • In radiography humanistic aspects are emphasized, a shift from the technological perspective. • The attributes demonstrate the essence and interdisciplinary nature of radiography. • This

  5. The comparison of microstructure and nanocluster evolution in proton and neutron irradiated Fe–9%Cr ODS steel to 3 dpa at 500 °C

    Energy Technology Data Exchange (ETDEWEB)

    Swenson, M.J., E-mail: matthewswenson1@u.boisestate.edu; Wharry, J.P.

    2015-12-15

    A model Fe–9%Cr oxide dispersion strengthened (ODS) steel was irradiated with protons or neutrons to a dose of 3 displacements per atom (dpa) at a temperature of 500 °C, enabling a direct comparison of ion to neutron irradiation effects at otherwise fixed irradiation conditions. The irradiated microstructures were characterized using transmission electron microscopy and atom probe tomography including cluster analysis. Both proton and neutron irradiations produced a comparable void and dislocation loop microstructure. However, the irradiation response of the Ti–Y–O oxide nanoclusters varied. Oxides remained stable under proton irradiation, but exhibited dissolution and an increase in Y:Ti composition ratio under neutron irradiation. Both proton and neutron irradiation also induced varying extents of Si, Ni, and Mn clustering at existing oxide nanoclusters. Protons are able to reproduce the void and loop microstructure of neutron irradiation carried out to the same dose and temperature. However, since nanocluster evolution is controlled by both diffusion and ballistic impacts, protons are rendered unable to reproduce the nanocluster evolution of neutron irradiation at the same dose and temperature. - Highlights: • Fe–9% Cr ODS was irradiated with protons and neutrons to 3 dpa at 500 °C. • Dislocation loop size and density were similar upon proton and neutron irradiation. • Oxide nanocluster size and density decreased more with neutron irradiation. • Oxide Y:Ti ratio increased from 0.54 to 0.97 upon neutron irradiation. • Irradiation induced enrichment of Si, Mn, and Ni at oxide locations.

  6. Heavy-ion radiography

    International Nuclear Information System (INIS)

    Fabrikant, J.I.; Tobias, C.A.; Holley, W.R.; Benton, E.V.

    1981-01-01

    Heavy-particle radiography has clinical potential as a newly developed noninvasive low-dose imaging procedure that provides increased resolution of minute density differences in soft tissues of the body. The method utilizes accelerated high-energy ions, primarily carbon and neon, at the Bevalac accelerator at the Lawrence Berkeley Laboratory. The research program for medicine utilizes heavy-ion radiography for low-dose mammography, for treatment planning for cancer patients, and for imaging and accurate densitometry of skeletal structures, brain and spinal neoplasms, and the heart. The potential of heavy-ion imaging, and particularly reconstruction tomography, is now proving to be an adjunct to existing diagnostic imaging procedures in medicine, both for applications to the diagnosis, management and treatment of clinical cancer in man, and for the early detection of small soft-tissue tumors at low radiation dose

  7. Projection radiography and tomography

    International Nuclear Information System (INIS)

    Tobias, C.A.; Fabrikant, J.I.; Benton, E.V.; Holley, W.R.

    1980-01-01

    Our program on heavy-ion radiography began soon after heavy ions were accelerated to high energies. Heavy ions are capable of very high electron density discrimination combined with good radial image resolution and low dose. Since heavy-ion beams produce many secondries, plastic nuclear detectors have an advantage for recording heavy-ion images. Projection imaging is now a practical technique that can resolve density differences between normal tissue and tumor tissue in some cases in which X rays could not make a distinction. Initial attempts at heavy-ion tomography also indicate potential for high resolution in this field. The physical basis for heavy-ion radiography and tomographic reconstruction studies are discussed in detail

  8. Dose in conventional radiography

    International Nuclear Information System (INIS)

    Acuna D, E.; Padilla R, Z. P.; Escareno J, E.; Vega C, H. R.

    2011-10-01

    It has been pointed out that medical exposures are the most significant sources of exposure to ionizing radiation for the general population. Inside the medical exposures the most important is the X-ray use for diagnosis, which is by far the largest contribution to the average dose received by the population. From all studies performed in radiology the chest radiography is the most abundant. In an X-ray machine, voltage and current are combined to obtain a good image and a reduce dose, however due to the workload in a radiology service individual dose is not monitored. In order to evaluate the dose due to chest radiography in this work a plate phantom was built according to the ISO recommendations using methylmethacrylate walls and water. The phantom was used in the Imaging department of the Zacatecas General Hospital as a radiology patient asking for a chest study; using thermoluminescent dosimeters, TLD 100 the kerma at the surface entrance was determined. (Author)

  9. Quantitative film radiography

    International Nuclear Information System (INIS)

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

    1991-01-01

    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

  10. Patient care in radiography

    International Nuclear Information System (INIS)

    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

  11. Digital chest radiography

    DEFF Research Database (Denmark)

    Debess, Jeanne Elisabeth; Vejle-Sørensen, Jens Kristian; Thomsen, Henrik

    ,3 mAs and SID SID of 180 centimetres using a phantom and lithium fluoride thermo luminescence dosimeter (TLD). Dose to risk organs mamma, thyroid and colon are measured at different collimations with one-centimetre steps. TLD results are used to estimate dose reduction for different collimations...... at the conference. Conclusion: Collimation improvement in basic chest radiography can reduce the radiation to female patients at chest x-ray examinations....

  12. Digital radiography in space.

    Science.gov (United States)

    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

  13. Panoramic dental radiography

    International Nuclear Information System (INIS)

    Cushman, R.H.; Kircher, D.R.; Hart, F.W.; Ciavattoni, A.

    1980-01-01

    Apparatus is described for improving the handling rate of patients in panoramic dental radiography when tube head-camera assembly of a low silhouette panoramic dental X-ray machine is rotated for a scan in one direction only. This is effected by fast return of the tube head-camera assembly with its simultaneous elevation, thus facilitating the radiographed patient's exit from the machine and the entrance of another patient. Fast speed is about twice the scanning speed. (author)

  14. Compton radiography, 1

    International Nuclear Information System (INIS)

    Okuyama, Shinichi; Sera, Koichiro; Fukuda, Hiroshi; Shishido, Fumio; Matsuzawa, Taiju

    1977-01-01

    Tomographic images of an object are obtainable by irradiating it with a collimated beam of monochromatic gamma rays and recording the resultant Compton rays scattered upward at right angles. This is the scattered-ray principle of the formation of a radiation image that differs from the traditional ''silhouette principle'' of radiography, and that bears prospects of stereopsis as well as cross-section tomography. (Evans, J.)

  15. Multiple ionization of noble gases by 2.0 MeV proton impact: comparison with equi-velocity electron impact ionization

    International Nuclear Information System (INIS)

    Melo, W.S.; Santos, A.C.F.; Sant'Anna, M.M.; Sigaud, G.M.; Montenegro, E.C.

    2002-01-01

    Absolute single- and multiple-ionization cross sections of rare gases (He, Ne, Ar, Kr and Xe) have been measured for collisions with 2.0 MeV p + . A comparison is made with equi-velocity electron impact ionization cross sections as well as with the available proton impact data. For the light rare gases the single-ionization cross sections are essentially the same for both proton and electron impacts, but increasing differences appear for the heavier targets. (author). Letter-to-the-editor

  16. An overview of digital radiography

    International Nuclear Information System (INIS)

    Aweligiba, S. A.

    2013-04-01

    The medical application of radiography has gained wider study since diagnostic radiology plays a very important role in modern medicine for fast diagnosis and therapy. Digital radiography is a relatively new technology that promises greater accuracy, lesser dose and better manipulation of patient radiology images in hospitals. In this study, a general discussion on digital radiography has been presented. The presentation focuses on the optimisation of doses to patients in the medical application of digital radiography, quality control and quality assurance. A brief presentation on performance indicators in digital radiography has also been presented. The advantages of digital radiography over the conventional film/screen system have been elaborated and its limitations are also outlined. (author)

  17. Preliminary examination of the applicability of imaging plates to fast neutron radiography

    International Nuclear Information System (INIS)

    Matsubayashi, Masahito; Hibiki, Takashi; Mishima, Kaichiro; Yoshii, Koji; Okamoto, Koji

    2001-01-01

    Fast neutron radiography is an attractive non-destructive inspection technique because of the excellent penetration characteristics of fast neutrons in matter. However, the difficulty of detecting fast neutrons reduces this attractive feature. As an experiment to overcome the difficulty, imaging plates were applied to fast neutron radiography. A simple combination of two sheets of imaging plates and a sheet of polyethylene as a proton emitter was examined with the (fast neutron, thermal neutron and gamma ray) FTG discriminator proposed by Yoneda et al. . The experimental results showed that the method could be applicable to fast neutron radiography with effective discrimination of γ-rays

  18. Introduction to industrial radiography

    International Nuclear Information System (INIS)

    Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

    2008-01-01

    For the first topic in this book, more on introduction to nondestructive testing, also a little bit on another technique such as magnetic testing, liquid penetrated, ultrasonic testing and others. This book mentions more on radiographic testing and for that, more details on this topic such as history, definition and devices that use in this technique. This radiography testing firstly started with the discovering of x-ray by Wilhelm Roentgen (1895). So, on 1913, David Coolidge successfully invented and developed x-ray tube that could made x-ray more intensified and produced highly penetration forces. Radiography in Malaysia firstly started two years after the discovery made by Wilhelm Roentgen when one hospital here used the x-ray machine for medical purposes. Besides using x-ray, radiography also used gamma rays, and for these purpose, they used Co-60 and Ir-192. Now, more company based on NDT established to provide a service on inspection pipe and others. For filled these requirement, radiographer must take an exam to make them expert and trained well to work in this field. There is no advantage using this technique or other technique. So that's why this book was published to make people understand what is radiographic testing truly.

  19. Apparatus for gamma radiography

    International Nuclear Information System (INIS)

    1983-06-01

    The aim of the present standard is to fix the rules for the construction of gamma radiography instrumentation without prejudice to the present regulations. These apparatus have to be fitted with only sealed sources conformable to the experimental standard M 61-002. The present standard agrees with the international standard ISO 3999 of 1977 dealing with the same subject. Nevertheless, it is different on the three main following points: it does not accept the same limits of absorbed dose rates in the air calculated on the external surface of projectors; it precribes tightness, bending, crushing and tensile tests for some components of the gamma radiography it prescribes tests of endurance and resistance to breaking for the locking systems of the gamma radiography apparatus. The present standard also specifies the following points: symbols and indications to put on projectors and on the source-holder; identification of the source contained in the projector; and, accompanying documents. The regulation references are given in annexe [fr

  20. First experience with digital radiography

    International Nuclear Information System (INIS)

    Buchmann, F.

    1987-01-01

    The digital radiogram is explained, its advantages being the various possibilities of image processing, loss-free transmission, recording and storage capabilities, and in special cases, prompt availability of processed images. Digital subtraction angiography (DSA) and the high-resolution method of digital, luminescent radiography, which replaced the conventional film-foil radiography, are explained as the first developments for the introduction of digital radiography, which today already is an applicable technique. (orig./MG) [de

  1. Neutron radiography of Apollo ordnance

    International Nuclear Information System (INIS)

    Golliher, K.G.

    1983-01-01

    Neutron radiography played an important role in the successful Apollo missions. Neutron radiography was used, for the first time, on a production basis to examine the internal details of ordnance devices employed in the Apollo Program. Ordnance devices ranged from charges which separated the massive booster stages to those which triggered the release of re-entry parachutes. Discussed are the early developments in neutron radiography and the conversion of this infant nondestructive technology into production capabilities. (Auth.)

  2. Deflection evaluation using time-resolved radiography

    International Nuclear Information System (INIS)

    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. The authors have applied time-resolved radiography to evaluate motions of explosive-driven events. In the particular application discussed in this paper, the author's 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

  3. Comparison of Geant4 multiple Coulomb scattering models with theory for radiotherapy protons.

    Science.gov (United States)

    Makarova, Anastasia; Gottschalk, Bernard; Sauerwein, Wolfgang

    2017-07-06

    Usually, Monte Carlo models are validated against experimental data. However, models of multiple Coulomb scattering (MCS) in the Gaussian approximation are exceptional in that we have theories which are probably more accurate than the experiments which have, so far, been done to test them. In problems directly sensitive to the distribution of angles leaving the target, the relevant theory is the Molière/Fano/Hanson variant of Molière theory (Gottschalk et al 1993 Nucl. Instrum. Methods Phys. Res. B 74 467-90). For transverse spreading of the beam in the target itself, the theory of Preston and Koehler (Gottschalk (2012 arXiv:1204.4470)) holds. Therefore, in this paper we compare Geant4 simulations, using the Urban and Wentzel models of MCS, with theory rather than experiment, revealing trends which would otherwise be obscured by experimental scatter. For medium-energy (radiotherapy) protons, and low-Z (water-like) target materials, Wentzel appears to be better than Urban in simulating the distribution of outgoing angles. For beam spreading in the target itself, the two models are essentially equal.

  4. Comparison of vonoprazan and proton pump inhibitors for eradication of Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Satoshi Shinozaki

    2016-05-01

    Full Text Available Alternative eradication therapies for Helicobacter pylori infection are needed because of an increasing failure rate over the past decade. The aim of this study was to determine if vonoprazan, a new potassium-competitive acid blocker, showed superiority to existing proton pump inhibitors for primary eradication of H. pylori in routine clinical practice. Data for 573 patients who underwent primary H. pylori eradication therapy were retrospectively reviewed. Regimens included clarithromycin 200 mg, amoxicillin 750 mg, and an acid-suppressing drug [lansoprazole 30 mg (LAC, rabeprazole 10 mg (RAC, esomeprazole 20 mg (EAC, or vonoprazan 20 mg (VAC] twice daily for 1 week. Eradication was successful in 73% (419/573 of patients using intention-to-treat (ITT analysis and 76% (419/549 of patients in per-protocol (PP analysis. The VAC group had a significantly superior eradication rate compared with the LAC and RAC groups in ITT (VAC 83%, LAC 66% and RAC 67%, p  80% eradication rate regardless of the degree of atrophy.

  5. Double beam neutron radiography facility

    International Nuclear Information System (INIS)

    Domanus, J.C.

    1977-09-01

    The DR1 reactor at Risoe is used as a neutron source for neutron radiography. In the double-beam neutron radiography facility a neutron flux of an intensity of 1.4 and 1.8 x 10 6 n. cm -2 . s -1 reaches the object to be radiographed. The transport and exposure container used for neutron radiography of irradiated nuclear fuel rods is described, and the exposure technique and procedure are reviewed. The mode by which single neutron radiographs are assembled and assessed is described. This report will be published in the ''Neutron Radiography Newsletter''. (author)

  6. Quality assurance in digital radiography

    International Nuclear Information System (INIS)

    Busch, H.P.; Lehmann, K.J.

    1989-01-01

    At present, there is no standard way of evaluating performance characteristics of digital radiography systems. Continuous measurements of performance parameters are necessary in order to obtain images of high quality. Parameters of quality assurance in digital radiography, which can be evaluated with simple, quick methods, are spatial resolution, low-contrast detectability, dynamic range and exposure dose. Spatial resolution was determined by a lead bar pattern, whereas the other parameters were measured by commercially available phantoms. Performance measurements of 10 digital subtraction angiography (DSA) units and one digital radiography system for unsubtracted digital radiography were assessed. From these results, recommendations for performance parameter levels will be discussed. (author)

  7. Digital image intensifier radiography. One year's experience with a Polytron system

    International Nuclear Information System (INIS)

    Busch, H.P.; Lehmann, K.J.; Georgi, M.

    1989-01-01

    Since January 1988, digital image intensifier radiography has been used in the Clinic in Mannheim for DSA examinations and also in place of conventional screen/film examinations. Measurements have shown that compared with 100 mm and film/screen formats, digital radiography has poorer spatial resolution, but improved contrast resolution. The most common use of digital radiography was for examinations of the gastrointestinal tract. Using the demonstration of the mucosal fine relief pattern as a criterion of image quality, digital image intensifier radiography was able to achieve this satisfactorily. Comparison with film/screen examinations showed no loss of diagnostic information. Advantages of image intensifier radiography are reduced radiation dose, the possibility of postprocessing and economy. On the basis of 399 examinations, digital image intensifier radiography is now firmly established as part of the daily routine of the Mannheim Clinic. (orig.) [de

  8. Proton MRI in the evaluation of pulmonary sarcoidosis: Comparison to chest CT

    International Nuclear Information System (INIS)

    Chung, Jonathan H.; Little, Brent P.; Forssen, Anna V.; Yong, Jin; Nambu, Atsushi; Kazlouski, Demitry; Puderbach, Michael; Biederer, Juergen; Lynch, David A.

    2013-01-01

    Purpose: The purpose of this study was to determine the feasibility of proton MRI of the lung in sarcoidosis patients and the agreement between the imaging appearance of pulmonary sarcoidosis on MRI and CT. Materials and methods: Chest CT scans and dedicated pulmonary MRI scans (including HASTE, VIBE, and TrueFISP sequences) were performed within 90 days of each other in 29 patients. The scans were scored for gross parenchymal opacification, reticulation, nodules, and masses using a 3-point lobar scale. Total and subset scores for corresponding MRI and CT scans were compared using the Spearman correlation test, Bland–Altman plots, and Cohen's quadratic-weighted kappa analysis. MRI scores were compared to CT by lobe and disease category, using percentage agreement, Spearman rank correlation, and Cohen's quadratic-weighted kappa. Results: The mean (±s.d.) time between MRI and CT scans was 33 ± 32 days. There was substantial correlation and agreement between total disease scoring on MRI and CT with a Spearman correlation coefficient of 0.774 (p < 0.0001) and a Cohen's weighted kappa score of 0.646. Correlation and agreement were highest for gross parenchymal opacification (0.695, 0.528) and reticulation (0.609, 0.445), and lowest in the setting of nodules (0.501, 0.305). Agreement testing was not performed for mass scores due to low prevalence. Upper lobe scoring on MRI and CT demonstrated greater agreement compared to the lower lobes (average difference in Cohen's weighted kappa score of 0.112). Conclusion: There is substantial correlation and agreement between MRI and CT in the scoring of pulmonary sarcoidosis, though MRI evaluation in the upper lobes may be more accurate than in the lower lobes

  9. Localised proton spectroscopy and spectroscopic imaging in cerebral gliomas, with comparison to positron emission tomography

    International Nuclear Information System (INIS)

    Go, K.G.; Kamman, R.L.; Mooyaart, E.L.; Heesters, M.A.A.M.; Pruim, J.; Vaalburg, W.; Paans, A.M.J.

    1995-01-01

    In 32 patients with gliomas, one- and two-dimensional proton magnetic resonance spectroscopy ( 1 H-MRS) has been conducted, the latter allowing reconstruction of spectroscopic data into a spectroscopic image (MRSI), showing the distribution of the various metabolite concentrations over the cross-sectional plane. For lack of absolute concentrations, the measured concentrations of phosphocholine (CHOL), N-acetyl-L-aspartate (NAA), and lactate (LAC) were conventionally expressed in ratios relative to that of creatine (CREAT). Compared to normal brain tissue, an increased CHOL/CREAT ratio was found in all groups of tumours, in glioblastomas, high-, middle- and low-grade astrocytomas both at the margin and the core of the tumours, but in oligodendrogliomas only at the margin. This is consistent with an increased phosphocholine turnover in relation to membrane biosynthesis by the proliferating cells. The NAA/CREAT ratio was decreased in all groups of tumours, both in the centre and at the margin, reflecting replacement of functioning neurons by neoplastic cells. The LAC/CREAT ratio was elevated in the core of malignant gliomas, which may be the result of a prevailing glycolysis, characteristic of tumours, possibly in conjunction with hypoxia/ischaemia. In the perifocal oedema, there was neither elevation of the CHOL/CREAT ratio nor decrease of the NAA/CREAT ratio; an increased LAC/CREAT ratio therefore rather reflected ischaemia/hypoxia probably due to locally elevated pressure and compromised regional perfusion. In the normal brain, the metabolite ratios of grey matter did not differ from those of white matter. The frontal lobe and basal ganglia showed lower NAA/CREAT ratios than the other cerebral areas. In 7 patients positron emission tomography was also performed with [ 18 F]fluoro-2-deoxy-D-glucose ( 18 FDG) or L-[1- 11 C]-tyrosine ( 11 C-TYR); the latter demonstrated a pattern of 11 C-TYR uptake similar to that of CHOL elevation in the MRSI. (orig.)

  10. Comparison of panoramic radiography and cone-beam computed tomography for qualitative and quantitative measurements regarding localization of permanent impacted maxillary canines

    Directory of Open Access Journals (Sweden)

    Çiğdem Sarıkır

    2017-01-01

    Full Text Available Objective: The purpose of this retrospective study was to compare the correlation between digital panoramic radiography (DPR and cone-beam computed tomography (CBCT evaluations for localization of impacted permanent maxillary canines (IPMCs and for other qualitative and quantitative parameters. Materials and Method: DPR and CBCT images of 60 patients (17 men and 43 women were examined independently by two observers. Correlations between DPR and CBCT images were evaluated regarding qualitative (bucco-palatal positioning of IPMCs, morphology and presence of root resorption of adjacent permanent lateral incisors, and contact relationship between IPMCs and adjacent permanent lateral incisors and quantitative (angle measurements variables. All evaluations were repeated 1 month later by each observer. Chi-square and t-tests were used for statistical analysis. Kappa statistics were used to assess intra- and interobserver agreement (Cohen’s κ. Results: No correlation was observed for determination of bucco-palatal positioning of IPMCs between DPR and CBCT images (p>0.05. Correlations were observed for other qualitative variables (p<0.05. Differences between DPR and CBCT images were seen for all examined quantitative variables (p<0.01. Intra- and interobserver agreements were substantial to almost-perfect. Conclusion: No significant correlation was found between DPR and CBCT images for determination of bucco-palatal positioning of IPMCs. All quantitative measurements performed on DPR and CBCT images significantly differed from each other.

  11. A comparison of real-time radiography results and visual characterization results with emphasis on WIPP WAC and TRAMPAC compliance issues

    International Nuclear Information System (INIS)

    Hailey, S.M.

    1994-01-01

    Visual characterization provides a means of confirming the real-time radiography (RTR) certification process and process knowledge. RTR and visual characterization have been conducted on thirty-three drums containing transuranic (TRU) waste in support of the Waste Isolation Pilot Plant (WIPP) Experimental Test Program (WETP) at the Idaho National Engineering Laboratory. Argonne National Laboratory - West (ANL-W) detected a small can of liquid in one of these drums during the visual examination, resulting in a WIPP Waste Acceptance Criteria (WIPP-WAC) miscertification. The remaining thirty-two drums were certified correctly by the RTR system at the Stored Waste Examination Pilot Plant (SWEPP) for WIPP-WAC and TRUPACT-II Authorized Methods for Payload Control (TRAMPAC) requirements. TRAMPAC contains restrictions on the weights of specific materials allowed in the waste, based on the shipping category. Items on the restricted list for a given shipping category are allowed in quantities less than 1 percent of the weight of the waste. RTR can estimate the weights of certain broad categories in homogeneous waste forms, however, the capability to estimate weights at the 1 percent level is not presently realistic. Process knowledge forms the basis of conformance to these weight requirements. Visual characterization suggests process knowledge is not completely adequate at this level

  12. Comparison of chest radiography, chest digital tomosynthesis and low dose MDCT to detect small ground-glass opacity nodules: an anthropomorphic chest phantom study

    International Nuclear Information System (INIS)

    Doo, Kyung Won; Kang, Eun-Young; Yong, Hwan Seok; Ham, Soo-Youn; Lee, Ki Yeol; Choo, Ji Yung

    2014-01-01

    The purpose of this study was to evaluate the diagnostic performance of chest radiography (CXR), chest digital tomosynthesis (DT) and low dose multidetector computed tomography (LDCT) for the detection of small pulmonary ground-glass opacity (GGO) nodules, using an anthropomorphic chest phantom. Artificial pulmonary nodules were placed in a phantom and a total of 40 samples of different nodule settings underwent CXR, DT and LDCT. The images were randomly read by three experienced chest radiologists. Free-response receiver-operating characteristics (FROC) were used. The figures of merit for the FROC curves averaged for the three observers were 0.41, 0.37 and 0.76 for CXR, DT and LDCT, respectively. FROC analyses revealed significantly better performance of LDCT over CXR or DT for the detection of GGO nodules (P < 0.05). The difference in detectability between CXR and DT was not statistically significant (P = 0.73). The diagnostic performance of DT for the detection of pulmonary small GGO nodules was not significantly different from that of CXR, but LDCT performed significantly better than both CXR and DT. DT is not a suitable alternative to CT for small GGO nodule detection, and LDCT remains the method of choice for this purpose. (orig.)

  13. Comparison of chest radiography, chest digital tomosynthesis and low dose MDCT to detect small ground-glass opacity nodules: an anthropomorphic chest phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Doo, Kyung Won; Kang, Eun-Young; Yong, Hwan Seok [Korea University Guro Hospital, Korea University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Ham, Soo-Youn [Korea University Anam Hospital, Korea University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Lee, Ki Yeol; Choo, Ji Yung [Korea University Ansan Hospital, Korea University College of Medicine, Department of Radiology, Ansan (Korea, Republic of)

    2014-12-15

    The purpose of this study was to evaluate the diagnostic performance of chest radiography (CXR), chest digital tomosynthesis (DT) and low dose multidetector computed tomography (LDCT) for the detection of small pulmonary ground-glass opacity (GGO) nodules, using an anthropomorphic chest phantom. Artificial pulmonary nodules were placed in a phantom and a total of 40 samples of different nodule settings underwent CXR, DT and LDCT. The images were randomly read by three experienced chest radiologists. Free-response receiver-operating characteristics (FROC) were used. The figures of merit for the FROC curves averaged for the three observers were 0.41, 0.37 and 0.76 for CXR, DT and LDCT, respectively. FROC analyses revealed significantly better performance of LDCT over CXR or DT for the detection of GGO nodules (P < 0.05). The difference in detectability between CXR and DT was not statistically significant (P = 0.73). The diagnostic performance of DT for the detection of pulmonary small GGO nodules was not significantly different from that of CXR, but LDCT performed significantly better than both CXR and DT. DT is not a suitable alternative to CT for small GGO nodule detection, and LDCT remains the method of choice for this purpose. (orig.)

  14. Gamma radiography and its technological application

    International Nuclear Information System (INIS)

    Courtois, G.

    1962-01-01

    After the presentation of gamma radiography and X-ray radiography, the author compare both techniques showing, in particular, the greater utility of gamma radiography in industrial diagnostic and more particularly on works site diagnostic. Problem of using radiography and safety consideration will be studied. Figures shows two radiography equipment which have been designed for gamma radiography respecting the safety regulations required by the Radioisotope Inter-ministerial Commission. In the second part, different techniques and uses of gamma radiography are briefly described : xerography, neutron radiography, fluoroscopy and imaging amplifier, tomography, betatrons and linear accelerators. Cost analysis will discussed in conclusion. (M.P.)

  15. Direct digital radiography versus storage phosphor radiography in the detection of wrist fractures

    Energy Technology Data Exchange (ETDEWEB)

    Peer, Siegfried; Neitzel, Ulrich; Giacomuzzi, Salvatore M.; Pechlaner, Sigurd; KUenzel, Karl Heinz; Peer, Regina; Gassner, Eva; Steingruber, Iris; Gaber, O.; Jaschke, Werner

    2002-04-01

    AIM: To define the value of digital radiography with a clinical flat panel detector system for evaluation of wrist fractures in comparison with state of the art storage phosphor radiography. MATERIAL AND METHODS: Hard copy images of 26 fractured wrist specimens were acquired with the same exposure dose on a state of the art storage phosphor radiography system and a clinical flat panel detector. Image features like cortical bone surface, trabecular bone, soft tissues and fracture delineation were independently analysed by 4 observers using a standardised protocol. Image quality ratings were evaluated with an analysis of variance (ANOVA). RESULTS: Flat panel detector radiographs were rated superior with respect to cortical and trabecular bone representation as well as fracture evaluation, while storage phosphor radiographs produced better soft tissue detail. CONCLUSION: In some of the observed image quality aspects, the performance of caesium iodide/amorphous silicon flat panel detector exceeds state of the art storage phosphor radiography. This makes it well suited for skeletal imaging particularly in trauma as seen in the detection of wrist fractures. Peer, S. et al. (2002)

  16. Direct digital radiography versus storage phosphor radiography in the detection of wrist fractures

    International Nuclear Information System (INIS)

    Peer, Siegfried; Neitzel, Ulrich; Giacomuzzi, Salvatore M.; Pechlaner, Sigurd; KUenzel, Karl Heinz; Peer, Regina; Gassner, Eva; Steingruber, Iris; Gaber, O.; Jaschke, Werner

    2002-01-01

    AIM: To define the value of digital radiography with a clinical flat panel detector system for evaluation of wrist fractures in comparison with state of the art storage phosphor radiography. MATERIAL AND METHODS: Hard copy images of 26 fractured wrist specimens were acquired with the same exposure dose on a state of the art storage phosphor radiography system and a clinical flat panel detector. Image features like cortical bone surface, trabecular bone, soft tissues and fracture delineation were independently analysed by 4 observers using a standardised protocol. Image quality ratings were evaluated with an analysis of variance (ANOVA). RESULTS: Flat panel detector radiographs were rated superior with respect to cortical and trabecular bone representation as well as fracture evaluation, while storage phosphor radiographs produced better soft tissue detail. CONCLUSION: In some of the observed image quality aspects, the performance of caesium iodide/amorphous silicon flat panel detector exceeds state of the art storage phosphor radiography. This makes it well suited for skeletal imaging particularly in trauma as seen in the detection of wrist fractures. Peer, S. et al. (2002)

  17. A Treatment Planning Comparison of Combined Photon-Proton Beams Versus Proton Beams-Only for the Treatment of Skull Base Tumors

    International Nuclear Information System (INIS)

    Feuvret, Loic; Noel, Georges; Weber, Damien C.; Pommier, Pascal; Ferrand, Regis; De Marzi, Ludovic; Dhermain, Frederic; Alapetite, Claire; Mammar, Hamid; Boisserie, Gilbert; Habrand, Jean-Louis; Mazeron, Jean-Jacques

    2007-01-01

    Purpose: To compare treatment planning between combined photon-proton planning (CP) and proton planning (PP) for skull base tumors, so as to assess the potential limitations of CP for these tumors. Methods and Materials: Plans for 10 patients were computed for both CP and PP. Prescribed dose was 67 cobalt Gray equivalent (CGE) for PP; 45 Gy (photons) and 22 CGE (protons) for CP. Dose-volume histograms (DVHs) were calculated for gross target volume (GTV), clinical target volume (CTV), normal tissues (NT), and organs at risk (OARs) for each plan. Results were analyzed using DVH parameters, inhomogeneity coefficient (IC), and conformity index (CI). Results: Mean doses delivered to the GTVs and CTVs with CP (65.0 and 61.7 CGE) and PP (65.3 and 62.2 Gy CGE) were not significantly different (p > 0.1 and p = 0.72). However, the dose inhomogeneity was drastically increased with CP, with a mean significant incremental IC value of 10.5% and CP of 6.8%, for both the GTV (p = 0.01) and CTV (p = 0.04), respectively. The CI 80% values for the GTV and CTV were significantly higher with PP compared with CP. Compared with CP, the use of protons only led to a significant reduction of NT and OAR irradiation, in the intermediate-to-low dose (≤80% isodose line) range. Conclusions: These results suggest that the use of CP results in levels of target dose conformation similar to those with PP. Use of PP significantly reduced the tumor dose inhomogeneity and the delivered intermediate-to-low dose to NT and OARs, leading us to conclude that this treatment is mainly appropriate for tumors in children

  18. Mass chest radiography in Greece

    International Nuclear Information System (INIS)

    Papavasiliou, C.

    1987-01-01

    In Greece mass chest radiography has been performed regularly on various population groups as a measure to control tuberculosis. Routine chest radiography is performed in most Greek hospitals on admission. In this report available data-admittedly inadequate-directly or indirectly addressing the problem of benefit versus the risk or cost associated with this examination is presented

  19. Student Incivility in Radiography Education.

    Science.gov (United States)

    Clark, Kevin R

    2017-07-01

    To examine student incivility in radiography classrooms by exploring the prevalence of uncivil behaviors along with the classroom management strategies educators use to manage and prevent classroom disruptions. A survey was designed to collect data on the severity and frequency of uncivil student behaviors, classroom management strategies used to address minor and major behavioral issues, and techniques to prevent student incivility. The participants were educators in radiography programs accredited by the Joint Review Committee on Education in Radiologic Technology. Findings indicated that severe uncivil student behaviors in radiography classrooms do not occur as often as behaviors classified as less severe. Radiography educators in this study used a variety of strategies and techniques to manage and prevent student incivility; however, radiography educators who received formal training in classroom management reported fewer incidents of student incivility than those who had not received formal training. The participants in this study took a proactive approach to addressing severe behavioral issues in the classroom. Many radiography educators transition from the clinical environment to the classroom setting with little to no formal training in classroom management. Radiography educators are encouraged to attend formal training sessions to learn how to manage the higher education classroom effectively. Student incivility is present in radiography classrooms. This study provides a foundation for future research on incivility. ©2017 American Society of Radiologic Technologists.

  20. Functioning of industrial radiography services

    International Nuclear Information System (INIS)

    Alves, R.N.; Costa, H.M. da; Bianchini, F.G.; Arrieta, L.A.I.

    1988-12-01

    The objective of this norm is establish the necessary requirements for the functioning of industrial radiography services, as well as the procedures for acquisition and transfer of radioactive sources and/or X-ray equipments used in industrial radiography [pt

  1. Radiography with polarised neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Michael L.

    2010-08-20

    In this thesis I present a new technique for the spatially resolved investigation of the magnetic properties of bulk samples. Standard one dimensional neutron depolarisation analysis is combined with neutron radiography to a method we call Neutron Depolarisation Imaging (NDI). The experimental setup which was installed at the neutron radiography beam line ANTARES at FRM II consists of a double crystal monochromator, neutron polariser, spin flipper, polarisation analyser and a position sensitive CCD detector. A comprehensive discussion of the requirements for these components is given and the limitations of the method are shown. The maximum spatial resolution which can be achieved with a neutron radiography setup is determined by the collimation of the neutron beam and the distance between sample and detector. Different types of polarisers have been tested and their advantages and disadvantages are discussed. A double crystal monochromator and a new type of polariser employing polarising neutron supermirrors based on the principle of an optical periscope were developed and tested during this work. Furthermore, NDI measurements on various samples of the weakly ferromagnetic materials Pd{sub 1-x}Ni{sub x} and Ni{sub 3}Al are presented. Neutron depolarisation radiography and tomography measurements were conducted with a spatial resolution as high as 0.3 mm on Pd{sub 1-x}Ni{sub x} and Ni{sub 3}Al samples. The feasibility of NDI experiments under hydrostatic pressures up to 10 kbar was shown on a sample of Ni{sub 3}Al using a modified Cu:Be clamp cell. A decrease of the ordering temperature by 2 K under hydrostatic pressure was determined from the NDI measurements and shows the potential of the method for further high pressure experiments. Additionally a method was developed which in principle allows to obtain the intrinsic dependence of the ordering temperature T{sub C} on the ordered moment Ms from NDI measurements on inhomogeneous samples containing regions with

  2. Radiography with polarised neutrons

    International Nuclear Information System (INIS)

    Schulz, Michael L.

    2010-01-01

    In this thesis I present a new technique for the spatially resolved investigation of the magnetic properties of bulk samples. Standard one dimensional neutron depolarisation analysis is combined with neutron radiography to a method we call Neutron Depolarisation Imaging (NDI). The experimental setup which was installed at the neutron radiography beam line ANTARES at FRM II consists of a double crystal monochromator, neutron polariser, spin flipper, polarisation analyser and a position sensitive CCD detector. A comprehensive discussion of the requirements for these components is given and the limitations of the method are shown. The maximum spatial resolution which can be achieved with a neutron radiography setup is determined by the collimation of the neutron beam and the distance between sample and detector. Different types of polarisers have been tested and their advantages and disadvantages are discussed. A double crystal monochromator and a new type of polariser employing polarising neutron supermirrors based on the principle of an optical periscope were developed and tested during this work. Furthermore, NDI measurements on various samples of the weakly ferromagnetic materials Pd 1-x Ni x and Ni 3 Al are presented. Neutron depolarisation radiography and tomography measurements were conducted with a spatial resolution as high as 0.3 mm on Pd 1-x Ni x and Ni 3 Al samples. The feasibility of NDI experiments under hydrostatic pressures up to 10 kbar was shown on a sample of Ni 3 Al using a modified Cu:Be clamp cell. A decrease of the ordering temperature by 2 K under hydrostatic pressure was determined from the NDI measurements and shows the potential of the method for further high pressure experiments. Additionally a method was developed which in principle allows to obtain the intrinsic dependence of the ordering temperature T C on the ordered moment Ms from NDI measurements on inhomogeneous samples containing regions with different ordering temperatures. This

  3. Single source dual-energy computed tomography in the diagnosis of gout: Diagnostic reliability in comparison to digital radiography and conventional computed tomography of the feet

    Energy Technology Data Exchange (ETDEWEB)

    Kiefer, Tobias; Diekhoff, Torsten [Department of Radiology, Charité—Universitätsmedizin Berlin, Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität, Berlin, Charitéplatz 1, 10117 Berlin (Germany); Hermann, Sandra [Department of Rheumatology and Clinical Immunology, Charité—Universitätsmedizin Berlin Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Charitéplatz 1, 10117 Berlin (Germany); Stroux, Andrea [Department of Medical Informatics, Biometry and Epidemiology, Freie Universität Berlin, Berlin (Germany); Mews, Jürgen; Blobel, Jörg [Toshiba Medical Systems Europe, BV, Zilverstraat 1, 2701 RP Zoetermeer (Netherlands); Hamm, Bernd [Department of Radiology, Charité—Universitätsmedizin Berlin, Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität, Berlin, Charitéplatz 1, 10117 Berlin (Germany); Hermann, Kay-Geert A., E-mail: kghermann@gmail.com [Department of Radiology, Charité—Universitätsmedizin Berlin, Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität, Berlin, Charitéplatz 1, 10117 Berlin (Germany)

    2016-10-15

    Objectives: To investigate the diagnostic value of single-source dual-energy computed tomography (SDECT) in gouty arthritis and to compare its capability to detect urate depositions with digital radiography (DR) and conventional computed tomography (CT). Methods: Forty-four patients who underwent SDECT volume scans of the feet for suspected gouty arthritis were retrospectively analyzed. SDECT, CT (both n = 44) and DR (n = 36) were scored by three blinded readers for presence of osteoarthritis, erosions, and tophi. A diagnosis was made for each imaging modality. Results were compared to the clinical diagnosis using the American College of Rheumatology (ACR) classification criteria. Results: The patient population was divided into a gout (n = 21) and control (n = 23) group based on final clinical diagnosis. Osteoarthritis was evident in 15 joints using CT and 30 joints using DR (p = 0.165). There were 134 erosions detected by CT compared to 38 erosions detected by DR (p < 0.001). In total 119 tophi were detected by SDECT, compared to 85 tophi by CT (p = 0.182) and 25 tophi by DR (p < 0.001). SDECT had best diagnostic value for diagnosis of gout compared to DR and conventional CT (sensitivity and specificity for SDECT: 71.4% and 95.7%, CT: 71.4% and 91.3% and DR: 44.4% and 83.3%, respectively). For all three readers, Cohen’s kappa for DR and conventional CT were substantial for all scoring items and ranged from 0.75 to 0.77 and 0.72–0.76, respectively. For SDECT Cohen’s kappa was good to almost perfect with 0.77–0.84. Conclusions: SDECT is capable to detect uric acid depositions with good sensitivity and high specificity in feet, therefore diagnostic confidence is improved. Using SDECT, inter-reader variance can be markedly reduced for the detection of gouty tophi.

  4. Comparison of Combined X-Ray Radiography and Magnetic Resonance (XMR) Imaging-Versus Computed Tomography-Based Dosimetry for the Evaluation of Permanent Prostate Brachytherapy Implants

    International Nuclear Information System (INIS)

    Acher, Peter; Rhode, Kawal; Morris, Stephen; Gaya, Andrew; Miquel, Marc; Popert, Rick; Tham, Ivan; Nichol, Janette; McLeish, Kate; Deehan, Charles; Dasgupta, Prokar; Beaney, Ronald; Keevil, Stephen F.

    2008-01-01

    Purpose: To present a method for the dosimetric analysis of permanent prostate brachytherapy implants using a combination of stereoscopic X-ray radiography and magnetic resonance (MR) imaging (XMR) in an XMR facility, and to compare the clinical results between XMR- and computed tomography (CT)-based dosimetry. Methods and Materials: Patients who had received nonstranded iodine-125 permanent prostate brachytherapy implants underwent XMR and CT imaging 4 weeks later. Four observers outlined the prostate gland on both sets of images. Dose-volume histograms (DVHs) were derived, and agreement was compared among the observers and between the modalities. Results: A total of 30 patients were evaluated. Inherent XMR registration based on prior calibration and optical tracking required a further automatic seed registration step that revealed a median root mean square registration error of 4.2 mm (range, 1.6-11.4). The observers agreed significantly more closely on prostate base and apex positions as well as outlining contours on the MR images than on those from CT. Coefficients of variation were significantly higher for observed prostate volumes, D90, and V100 parameters on CT-based dosimetry as opposed to XMR. The XMR-based dosimetry showed little agreement with that from CT for all observers, with D90 95% limits of agreement ranges of 65, 118, 79, and 73 Gy for Observers 1, 2, 3, and 4, respectively. Conclusions: The study results showed that XMR-based dosimetry offers an alternative to other imaging modalities and registration methods with the advantages of MR-based prostate delineation and confident three-dimensional reconstruction of the implant. The XMR-derived dose-volume histograms differ from the CT-derived values and demonstrate less interobserver variability

  5. Single source dual-energy computed tomography in the diagnosis of gout: Diagnostic reliability in comparison to digital radiography and conventional computed tomography of the feet

    International Nuclear Information System (INIS)

    Kiefer, Tobias; Diekhoff, Torsten; Hermann, Sandra; Stroux, Andrea; Mews, Jürgen; Blobel, Jörg; Hamm, Bernd; Hermann, Kay-Geert A.

    2016-01-01

    Objectives: To investigate the diagnostic value of single-source dual-energy computed tomography (SDECT) in gouty arthritis and to compare its capability to detect urate depositions with digital radiography (DR) and conventional computed tomography (CT). Methods: Forty-four patients who underwent SDECT volume scans of the feet for suspected gouty arthritis were retrospectively analyzed. SDECT, CT (both n = 44) and DR (n = 36) were scored by three blinded readers for presence of osteoarthritis, erosions, and tophi. A diagnosis was made for each imaging modality. Results were compared to the clinical diagnosis using the American College of Rheumatology (ACR) classification criteria. Results: The patient population was divided into a gout (n = 21) and control (n = 23) group based on final clinical diagnosis. Osteoarthritis was evident in 15 joints using CT and 30 joints using DR (p = 0.165). There were 134 erosions detected by CT compared to 38 erosions detected by DR (p < 0.001). In total 119 tophi were detected by SDECT, compared to 85 tophi by CT (p = 0.182) and 25 tophi by DR (p < 0.001). SDECT had best diagnostic value for diagnosis of gout compared to DR and conventional CT (sensitivity and specificity for SDECT: 71.4% and 95.7%, CT: 71.4% and 91.3% and DR: 44.4% and 83.3%, respectively). For all three readers, Cohen’s kappa for DR and conventional CT were substantial for all scoring items and ranged from 0.75 to 0.77 and 0.72–0.76, respectively. For SDECT Cohen’s kappa was good to almost perfect with 0.77–0.84. Conclusions: SDECT is capable to detect uric acid depositions with good sensitivity and high specificity in feet, therefore diagnostic confidence is improved. Using SDECT, inter-reader variance can be markedly reduced for the detection of gouty tophi.

  6. Digital radiography of the chest

    International Nuclear Information System (INIS)

    Sakurai, Kenji; Hachiya, Junichi; Korenaga, Tateo; Nitatori, Toshiaki; Miyasaka, Yasuo; Furuya, Yoshiro

    1984-01-01

    Initial clinical experience in digital chest radiography utilizing photostimulable phosphor and scanning laser stimulated luminescence was reported. Image quality of conventional film/screen radiography and digital radiography was compared in 30 normal cases. Reflecting wide dynamic range of the system, improved image quality was confirmed in all 30 cases, particularly in visibility of various mediastinal structures and pulmonary vessels. High sensor sensitivity of the system enabled digital radiography to reduce radiation dose requirement significantly. Diagnostically acceptable chest images were obtained with approximately 1/5 of routine dose for conventional radiography without significant image quality degradation. Some artifact created by digital processing were mostly overcome by a routine use of simultaneous display of two different types of image processing and therefore was not an actual drawback from diagnostic standpoint. Further technical advancement of the system to be seen for digital storage, retrieval and tranceference of images. (author)

  7. A system for fast neutron radiography

    International Nuclear Information System (INIS)

    Klann, R.T.

    1997-01-01

    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

  8. Comparison of Out-Of-Field Neutron Equivalent Doses in Scanning Carbon and Proton Therapies for Cranial Fields

    DEFF Research Database (Denmark)

    Athar, B.; Henker, K.; Jäkel, O.

    2010-01-01

    Purpose: The purpose of this analysis is to compare the secondary neutron lateral doses from scanning carbon and proton beam therapies. Method and Materials: We simulated secondary neutron doses for out-of-field organs in an 11-year old male patient. Scanned carbon and proton beams were simulated...

  9. Comparison of inclusive particle production in 14.6 GeV/c proton-nucleus collisions with simulation

    International Nuclear Information System (INIS)

    Jaffe, D.E.; Lo, K.H.; Comfort, J.R.; Sivertz, M.

    2006-01-01

    Inclusive charged pion, kaon, proton and deuteron production in 14.6 GeV/c proton-nucleus collisions measured by BNL experiment E802 is compared with results from the GEANT3, GEANT4 and FLUKA simulation packages. The FLUKA package is found to have the best overall agreement

  10. A comparison of two prompt gamma imaging techniques with collimator-based cameras for range verification in proton therapy

    Science.gov (United States)

    Lin, Hsin-Hon; Chang, Hao-Ting; Chao, Tsi-Chian; Chuang, Keh-Shih

    2017-08-01

    In vivo range verification plays an important role in proton therapy to fully utilize the benefits of the Bragg peak (BP) for delivering high radiation dose to tumor, while sparing the normal tissue. For accurately locating the position of BP, camera equipped with collimators (multi-slit and knife-edge collimator) to image prompt gamma (PG) emitted along the proton tracks in the patient have been proposed for range verification. The aim of the work is to compare the performance of multi-slit collimator and knife-edge collimator for non-invasive proton beam range verification. PG imaging was simulated by a validated GATE/GEANT4 Monte Carlo code to model the spot-scanning proton therapy and cylindrical PMMA phantom in detail. For each spot, 108 protons were simulated. To investigate the correlation between the acquired PG profile and the proton range, the falloff regions of PG profiles were fitted with a 3-line-segment curve function as the range estimate. Factors including the energy window setting, proton energy, phantom size, and phantom shift that may influence the accuracy of detecting range were studied. Results indicated that both collimator systems achieve reasonable accuracy and good response to the phantom shift. The accuracy of range predicted by multi-slit collimator system is less affected by the proton energy, while knife-edge collimator system can achieve higher detection efficiency that lead to a smaller deviation in predicting range. We conclude that both collimator systems have potentials for accurately range monitoring in proton therapy. It is noted that neutron contamination has a marked impact on range prediction of the two systems, especially in multi-slit system. Therefore, a neutron reduction technique for improving the accuracy of range verification of proton therapy is needed.

  11. Digital radiography: study of an alternative technique to conventional radiography

    International Nuclear Information System (INIS)

    Banchet, J.; Tisseur, D.; Thomas, A.

    2009-01-01

    Digital radiography, already in use in many industrial applications, appears as a potential alternative technique to conventional radiography in the nuclear field (and more especially to the inspection of welded joints). The advantages of digital radiography are a reduced explosion risk (due to the use of lower energy and activity sources), a lower installation time, a reduced exclusion zone, and the absence of effluents. However, to the contrary of the US case, this technique may not be used in France as it is not referenced in the regulating codes (RCCM, etc.). Areva has launched a R and D study in order to characterize the equivalencies between digital and conventional radiography. First results of this study are given

  12. Spherical nanoindentation of proton irradiated 304 stainless steel: A comparison of small scale mechanical test techniques for measuring irradiation hardening

    Science.gov (United States)

    Weaver, Jordan S.; Pathak, Siddhartha; Reichardt, Ashley; Vo, Hi T.; Maloy, Stuart A.; Hosemann, Peter; Mara, Nathan A.

    2017-09-01

    Experimentally quantifying the mechanical effects of radiation damage in reactor materials is necessary for the development and qualification of new materials for improved performance and safety. This can be achieved in a high-throughput fashion through a combination of ion beam irradiation and small scale mechanical testing in contrast to the high cost and laborious nature of bulk testing of reactor irradiated samples. The current work focuses on using spherical nanoindentation stress-strain curves on unirradiated and proton irradiated (10 dpa at 360 °C) 304 stainless steel to quantify the mechanical effects of radiation damage. Spherical nanoindentation stress-strain measurements show a radiation-induced increase in indentation yield strength from 1.36 GPa to 2.72 GPa and a radiation-induced increase in indentation work hardening rate of 10 GPa-30 GPa. These measurements are critically compared against Berkovich nanohardness, micropillar compression, and micro-tension measurements on the same material and similar grain orientations. The ratio of irradiated to unirradiated yield strength increases by a similar factor of 2 when measured via spherical nanoindentation or Berkovich nanohardness testing. A comparison of spherical indentation stress-strain curves to uniaxial (micropillar and micro-tension) stress-strain curves was achieved using a simple scaling relationship which shows good agreement for the unirradiated condition and poor agreement in post-yield behavior for the irradiated condition. The disagreement between spherical nanoindentation and uniaxial stress-strain curves is likely due to the plastic instability that occurs during uniaxial tests but is absent during spherical nanoindentation tests.

  13. Radiography geometry principle

    International Nuclear Information System (INIS)

    Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

    2008-01-01

    If one object placed in the field under the sun, we can see the shadow of that object in two dimensional where that object was placed. Nevertheless, the sun cannot penetrate deeply so that it will produce the shadow with same object. This principal also same as radiography, however, with ionizing radiation, it can penetrate through the object so that the image that produced not only the shadow of the object but also what are inside the object. So this can give advantages for the radiographer to make inspection what are inside this object. The images that produce depend with the shape, density, thickness and distance between the object, film and source. The reader also will introduce with some term such as Distance source to film, distance source to object, and distance object to film also some basic on DIN standard and API 1104 Standard.

  14. Improvements relating to radiography

    International Nuclear Information System (INIS)

    Bollen, R.H.; Vandenabeele, H.

    1977-01-01

    An improved combination of photosensitive materials suitable for use in radiography is described, with particular reference to a combination for an X-ray intensifying screen of the fluorescent type and a silver halide recorder. The intensifying material comprises a phosphor consisting wholly or mainly of a rare earth metal activated lanthanum oxyhalide, having more than half its spectral energy emission > 410 nm wavelength, more than half its visible light spectral energy emission in the range 400 to 500 nm, and its maximum energy emission peak in the range 400 to 450 nm. The phosphor should have a coverage of at least 200 to 800 g of the oxyhalide per sq. m. The screen material also contains a dye or pigment that absorbs light within the emission spectrum of the phosphor. The photosensitive recording material incorporates at least one silver halide emulsion layer. The combination should give a screen intensification factor of at least 20 to 40 kV. (U.K.)

  15. Investigation of radiation exposure dosage in dental and panoramic radiography

    International Nuclear Information System (INIS)

    Ishii, Kenichi

    2005-01-01

    Dental radiography and a 10-sheet procedure were conducted at 10 sites in the maxillomandibular anterior teeth and at both sides of the premolar and molar teeth sections with and without a protective apron (total 22 patterns). Experiments, which included a total of five patterns, involving standard ortho-radiography were performed with and without a protective apron, positioning of an apron exclusively on the anterior or the posterior portion of the body and utility of an apron that covered the entire body. Results are as follows: In dental radiography, internal organs included in a bundle demonstrated high radiation exposure, whereas organs excluded from the bundle exhibited low radiation exposure. In organs situated below the thyroid gland, utilization of aprons resulted in lower radiation exposure. In ortho-radiography, radiation exposure was greatest in the parotid gland, followed by the mandibular, sublingual and thyroid glands, respectively. The protective apron resulted in lower radiation exposure at sites situated below the mammary glands; moreover, a protector covering the entire body led to lower radiation exposure in comparison to an apron worn exclusively on the anterior or the posterior aspect of the body. No significant difference was observed in terms of exposure between protective aprons worn on the anterior or the posterior aspect of the body. Furthermore, a protective collar resulted in nearly zero radiation exposure in the thyroid gland. However, a protective collar largely interferes with interpretation of the radiograph; thus, in order to produce interpretable radiographs, protection of the thyroid gland is not possible. In conclusion, radiation exposure dosage can be reduced via utilization of a protective apron positioned below the thyroid gland during dental radiography and below the mammary glands during ortho-radiography. We confirmed evidence indicating that application of a protective apron can reduce patient radiation exposure dosage

  16. Neutron radiography using neutron imaging plate

    International Nuclear Information System (INIS)

    Chankow, Nares; Wonglee, Sarinrat

    2008-01-01

    Full text: The aims of this research are to study properties of neutron imaging plate, to obtain a suitable condition for neutron radiography and to use the neutron imaging plate for testing of materials nondestructively. The experiments were carried out by using a neutron beam from the Thai Research Reactor TRR-1/M1 at a power of 1.2 MW. A BAS-ND 2040 FUJI neutron imaging plate and a MX125 Kodak X-ray film/Gadolinium neutron converter screen combination were tested for comparison. It was found that the photostimulated light (PSL) read out of the imaging plate was directly proportional to the exposure time. It was also found that radiography with neutron using the imaging plate was approximately 40 times faster than the conventional neutron radiography using x-ray film/Gd converter screen combination. The sensitivity of the imaging plate to gamma-rays was investigated by using gamma-rays from an 192 Ir and a 60 Co radiographic sources. The imaging plate was found to be 5-6 times less sensitive to gamma-rays than a FUJI BAS-MS 2040 gamma-ray imaging plate. Finally, some specimens were selected to be radiographed with neutrons using the imaging plate and the x-ray film/Gd converter screen combination in comparison to x-rays. Parts containing light elements could be clearly observed by the two neutron radiographic techniques. It could be concluded that the image quality from the neutron imaging plate was comparable to the conventional x-ray film/Gd converter screen combination but the exposure time could be approximately reduced by a factor of 40

  17. Euratom Neutron Radiography Working Group

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1986-01-01

    reactor fuel as well as establish standards for radiographic image quality of neutron radiographs. The NRWG meets once a year in each of the neutron radiography centers to review the progress made and draw plans for the future. Besides, ad-hoc sub-groups or. different topics within the field of neutron......In 1979 a Neutron Radiography Working Group (NRWG) was constituted within Buratom with the participation of all centers within the European Community at which neutron facilities were available. The main purpose of NRWG was to standardize methods and procedures used in neutron radiography of nuclear...... radiography are constituted. This paper reviews the activities and achievements of the NRWG and its sub-groups....

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Radiography) - Bone Bone x-ray uses a very small dose of ionizing radiation to produce pictures of ... exposing a part of the body to a small dose of ionizing radiation to produce pictures of ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... will analyze the images and send a signed report to your primary care or referring physician , who ... Medicine Radiation Safety How to Read Your Radiology Report Images related to X-ray (Radiography) - Bone Sponsored ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... to X-ray (Radiography) - Bone Sponsored by Please note RadiologyInfo.org is not a medical facility. Please ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  1. Radiation Effects in Paediatric radiography

    International Nuclear Information System (INIS)

    Mutwasi, O.

    2006-01-01

    Diagnostic imaging has evolved from single technique to a field which we have a choice from many modalities. Some without radiation. Radiation producing modalities include plain films (low dose), Fluoroscopy (mid range dose), Computed tomography (high dose). Radiography dose can significantly be influenced in plain radiography by varying speed of screens, cassette construction and type of radiography. E.g. digital or computed. In computed or digital radiography we are no longer able to tell h igh dose b y the quality of images. The final image is by great extend a product of post processing algorithms. It's for this reasons that the basic understanding of the sensitivity and specifying of various types of examinations and of specifically radiation effects is mandatory for a paediatric imager

  2. A comparison of ionizing radiation damage in CMOS devices from 60Co gamma rays, electrons and protons

    International Nuclear Information System (INIS)

    He Baoping; Yao Zhibin; Zhang Fengqi

    2009-01-01

    Radiation hardened CC4007RH and non-radiation hardened CC4011 devices were irradiated using 60 Co gamma rays, 1 MeV electrons and 1-9 MeV protons to compare the ionizing radiation damage of the gamma rays with the charged particles. For all devices examined, with experimental uncertainty, the radiation induced threshold voltage shifts (ΔV th ) generated by 60 Co gamma rays are equal to that of 1 MeV electron and 1-7 MeV proton radiation under 0 gate bias condition. Under 5 V gate bias condition, the distinction of threshold voltage shifts (ΔV th ) generated by 60 Co gamma rays and 1 MeV electrons irradiation are not large, and the radiation damage for protons below 9 MeV is always less than that of 60 Co gamma rays. The lower energy the proton has, the less serious the radiation damage becomes. (authors)

  3. Dosimetric comparison between proton and photon beams in the moving gap region in cranio-spinal irradiation (CSI)

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chee-Wai; Das, Indra J.; Zhao, Li; Wolanski, Mark; Johnstone, Peter A.S.; Buchsbaum, Jeffrey C. [IU Health Proton Therapy Center, Bloomington (United States); Dept. of Radiation Oncology, Indiana Univ. School of Medicine, Indianapolis (United States)], e-mail: ccheng1@iuhealth.org; Srivastava, Shiv P. [Dept. of Radiation Oncology, Indiana Univ. School of Medicine, Indianapolis (United States); Dept. of Radiation Oncology, Reid Hospital, Richmond (United States); Simmons, Joseph [IU Health Proton Therapy Center, Bloomington (United States)

    2013-04-15

    Purpose: To investigate the moving gap region dosimetry in proton beam cranio-spinal irradiation (CSI) to provide optimal dose uniformity across the treatment volume. Material and methods: Proton beams of ranges 11.6 cm and 16 cm are used for the spine and the brain fields, respectively. Beam profiles for a 30 cm snout are first matched at the 50% level (hot match) on the computer. Feathering is simulated by shifting the dose profiles by a known distance two successive times to simulate a 2 x feathering scheme. The process is repeated for 2 mm and 4 mm gaps. Similar procedures are used to determine the dose profiles in the moving gap for a series of gap widths, 0-10 mm, and feathering step sizes, 4-10 mm, for a Varian iX 6MV beam. The proton and photon dose profiles in the moving gap region are compared. Results: The dose profiles in the moving gap exhibit valleys and peaks in both proton and photon beam CSI. The dose in the moving gap for protons is around 100% or higher for 0 mm gap, for both 5 and 10 mm feathering step sizes. When the field gap is comparable or larger than the penumbra, dose minima as low as 66% is obtained. The dosimetric characteristics for 6 MV photon beams can be made similar to those of the protons by appropriately combining gap width and feathering step size. Conclusion: The dose in the moving gap region is determined by the lateral penumbras, the width of the gap and the feathering step size. The dose decreases with increasing gap width or decreasing feathering step size. The dosimetric characteristics are similar for photon and proton beams. However, proton CSI has virtually no exit dose and is beneficial for pediatric patients, whereas with photon beams the whole lung and abdomen receive non-negligible exit dose.

  4. SU-F-J-64: Comparison of Dosimetric Robustness Between Proton Therapy and IMRT Plans Following Tumor Regression for Locally Advanced Non-Small Cell Lung Cancer (NSCLC)

    Energy Technology Data Exchange (ETDEWEB)

    Teng, C; Ainsley, C; Teo, B; Burgdorf, B; Berman, A; Levin, W; Xiao, Y; Lin, L; Simone, C; Solberg, T [University of Pennsylvania, Philadelphia, PA (United States); Janssens, G [IBA, Louvain-la-Neuve (Belgium)

    2016-06-15

    Purpose: In the light of tumor regression and normal tissue changes, dose distributions can deviate undesirably from what was planned. As a consequence, replanning is sometimes necessary during treatment to ensure continued tumor coverage or to avoid overdosing organs at risk (OARs). Proton plans are generally thought to be less robust than photon plans because of the proton beam’s higher sensitivity to changes in tissue composition, suggesting also a higher likely replanning rate due to tumor regression. The purpose of this study is to compare dosimetric deviations between forward-calculated double scattering (DS) proton plans with IMRT plans upon tumor regression, and assesses their impact on clinical replanning decisions. Methods: Ten consecutive locally advanced NSCLC patients whose tumors shrank > 50% in volume and who received four or more CT scans during radiotherapy were analyzed. All the patients received proton radiotherapy (6660 cGy, 180 cGy/fx). Dosimetric robustness during therapy was characterized by changes in the planning objective metrics as well as by point-by-point root-mean-squared differences for the entire PTV, ITV, and OARs (heart, cord, esophagus, brachial plexus and lungs) DVHs. Results: Sixty-four pairs of DVHs were reviewed by three clinicians, who requested a replanning rate of 16.7% and 18.6% for DS and IMRT plans, respectively, with a high agreement between providers. Robustness of clinical indicators was found to depend on the beam orientation and dose level on the DVH curve. Proton dose increased most in OARs distal to the PTV along the beam path, but these changes were primarily in the mid to low dose levels. In contrast, the variation in IMRT plans occurred primarily in the high dose region. Conclusion: Robustness of clinical indicators depends where on the DVH curves comparisons are made. Similar replanning rates were observed for DS and IMRT plans upon large tumor regression.

  5. Comparison of risk of radiogenic second cancer following photon and proton craniospinal irradiation for a pediatric medulloblastoma patient

    Science.gov (United States)

    Zhang, Rui; Howell, Rebecca M.; Giebeler, Annelise; Taddei, Phillip J.; Mahajan, Anita; Newhauser, Wayne D.

    2013-02-01

    Pediatric patients who received radiation therapy are at risk of developing side effects such as radiogenic second cancer. We compared proton and photon therapies in terms of the predicted risk of second cancers for a 4 year old medulloblastoma patient receiving craniospinal irradiation (CSI). Two CSI treatment plans with 23.4 Gy or Gy (RBE) prescribed dose were computed: a three-field 6 MV photon therapy plan and a four-field proton therapy plan. The primary doses for both plans were determined using a commercial treatment planning system. Stray radiation doses for proton therapy were determined from Monte Carlo simulations, and stray radiation doses for photon therapy were determined from measured data. Dose-risk models based on the Biological Effects of Ionization Radiation VII report were used to estimate the risk of second cancer in eight tissues/organs. Baseline predictions of the relative risk for each organ were always less for proton CSI than for photon CSI at all attained ages. The total lifetime attributable risk of the incidence of second cancer considered after proton CSI was much lower than that after photon CSI, and the ratio of lifetime risk was 0.18. Uncertainty analysis revealed that the qualitative findings of this study were insensitive to any plausible changes of dose-risk models and mean radiation weighting factor for neutrons. Proton therapy confers lower predicted risk of second cancer than photon therapy for the pediatric medulloblastoma patient.

  6. Non-destructive evaluation utilizing imaging plates for field radiography applications

    International Nuclear Information System (INIS)

    White, Brian S.

    2016-01-01

    The oil and gas industry has utilized film radiography for the evaluation of pipeline welds for many years. The world has evolved, and today people are easily sharing digital images as part of the information revolution. Computed radiography is ready to replace film radiography for portable outdoor use applications. Computed radiography technology adoption has been contingent upon achieving acceptable image quality and getting enough imaging plate use cycles to be profitable. Image quality is dependent upon shot conditions, imaging plate type, reader settings, and scatter control. Likewise, the number of achievable use cycles is dependent upon the imaging plate design for durability and the user's operating environment. This presentation reviews the basic principles of storage phosphor imaging plates. Usage criteria and guidelines for optimum image quality and maximized overall use cycles will be discussed for various imaging plate types. A comparison of film and computed radiography imaging plate technology will be presented.

  7. Measurements of lateral penumbra for uniform scanning proton beams under various beam delivery conditions and comparison to the XiO treatment planning system

    International Nuclear Information System (INIS)

    Rana, Suresh; Zeidan, Omar; Ramirez, Eric; Rains, Michael; Gao, Junfang; Zheng, Yuanshui

    2013-01-01

    Purpose: The main purposes of this study were to (1) investigate the dependency of lateral penumbra (80%–20% distance) of uniform scanning proton beams on various factors such as air gap, proton range, modulation width, compensator thickness, and depth, and (2) compare the lateral penumbra calculated by a treatment planning system (TPS) with measurements.Methods: First, lateral penumbra was measured using solid–water phantom and radiographic films for (a) air gap, ranged from 0 to 35 cm, (b) proton range, ranged from 8 to 30 cm, (c) modulation, ranged from 2 to 10 cm, (d) compensator thickness, ranged from 0 to 20 cm, and (e) depth, ranged from 7 to 15 cm. Second, dose calculations were computed in a virtual water phantom using the XiO TPS with pencil beam algorithm for identical beam conditions and geometrical configurations that were used for the measurements. The calculated lateral penumbra was then compared with the measured one for both the horizontal and vertical scanning magnets of our uniform scanning proton beam delivery system.Results: The results in the current study showed that the lateral penumbra of horizontal scanning magnet was larger (up to 1.4 mm for measurement and up to 1.0 mm for TPS) compared to that of vertical scanning magnet. Both the TPS and measurements showed an almost linear increase in lateral penumbra with increasing air gap as it produced the greatest effect on lateral penumbra. Lateral penumbra was dependent on the depth and proton range. Specifically, the width of lateral penumbra was found to be always lower at shallower depth than at deeper depth within the spread out Bragg peak (SOBP) region. The lateral penumbra results were less sensitive to the variation in the thickness of compensator, whereas lateral penumbra was independent of modulation. Overall, the comparison between the results of TPS with that of measurements indicates a good agreement for lateral penumbra, with TPS predicting higher values compared to

  8. Comparison of the microstructure, deformation and crack initiation behavior of austenitic stainless steel irradiated in-reactor or with protons

    Science.gov (United States)

    Stephenson, Kale J.; Was, Gary S.

    2015-01-01

    The objective of this study was to compare the microstructures, microchemistry, hardening, susceptibility to IASCC initiation, and deformation behavior resulting from proton or reactor irradiation. Two commercial purity and six high purity austenitic stainless steels with various solute element additions were compared. Samples of each alloy were irradiated in the BOR-60 fast reactor at 320 °C to doses between approximately 4 and 12 dpa or by a 3.2 MeV proton beam at 360 °C to a dose of 5.5 dpa. Irradiated microstructures consisted mainly of dislocation loops, which were similar in size but lower in density after proton irradiation. Both irradiation types resulted in the formation of Ni-Si rich precipitates in a high purity alloy with added Si, but several other high purity neutron irradiated alloys showed precipitation that was not observed after proton irradiation, likely due to their higher irradiation dose. Low densities of small voids were observed in several high purity proton irradiated alloys, and even lower densities in neutron irradiated alloys, implying void nucleation was in process. Elemental segregation at grain boundaries was very similar after each irradiation type. Constant extension rate tensile experiments on the alloys in simulated light water reactor environments showed excellent agreement in terms of the relative amounts of intergranular cracking, and an analysis of localized deformation after straining showed a similar response of cracking to surface step height after both irradiation types. Overall, excellent agreement was observed after proton and reactor irradiation, providing additional evidence that proton irradiation is a useful tool for accelerated testing of irradiation effects in austenitic stainless steel.

  9. Comparison of the microstructure, deformation and crack initiation behavior of austenitic stainless steel irradiated in-reactor or with protons

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, Kale J., E-mail: kalejs@umich.edu; Was, Gary S.

    2015-01-15

    Highlights: • Dislocation loops were the prominent defect, but neutron irradiation caused higher loop density. • Grain boundaries had similar amounts of radiation-induced segregation. • The increment in hardness and yield stress due to irradiation were very similar. • Relative IASCC susceptibility was nearly identical. • The effect of dislocation channel step height on IASCC was similar. - Abstract: The objective of this study was to compare the microstructures, microchemistry, hardening, susceptibility to IASCC initiation, and deformation behavior resulting from proton or reactor irradiation. Two commercial purity and six high purity austenitic stainless steels with various solute element additions were compared. Samples of each alloy were irradiated in the BOR-60 fast reactor at 320 °C to doses between approximately 4 and 12 dpa or by a 3.2 MeV proton beam at 360 °C to a dose of 5.5 dpa. Irradiated microstructures consisted mainly of dislocation loops, which were similar in size but lower in density after proton irradiation. Both irradiation types resulted in the formation of Ni–Si rich precipitates in a high purity alloy with added Si, but several other high purity neutron irradiated alloys showed precipitation that was not observed after proton irradiation, likely due to their higher irradiation dose. Low densities of small voids were observed in several high purity proton irradiated alloys, and even lower densities in neutron irradiated alloys, implying void nucleation was in process. Elemental segregation at grain boundaries was very similar after each irradiation type. Constant extension rate tensile experiments on the alloys in simulated light water reactor environments showed excellent agreement in terms of the relative amounts of intergranular cracking, and an analysis of localized deformation after straining showed a similar response of cracking to surface step height after both irradiation types. Overall, excellent agreement was observed

  10. Comparison of different hadron production models for the study of π±, K±, protons and antiprotons production in proton-carbon interactions at 90 GeV/c

    Science.gov (United States)

    Ajaz, M.; Ali, Y.; Ullah, S.; Ali, Q.; Tabassam, U.

    2018-05-01

    In this research paper, comprehensive results on the double differential yield of π± and K± mesons, protons and antiprotons as a function of laboratory momentum in several polar angle ranges from 0-420 mrad for pions, 0-360 mrad for kaons, proton and antiproton are reported. EPOS 1.99, EPOS-LHC and QGSJETII-04 models are used to perform simulations. The predictions of these models at 90 GeV/c are plotted for comparison, which shows that QGSJETII-04 model gives overall higher yield for π+ mesons in the polar angle interval of 0-40 mrad but for the π‑ the yield is higher only up to 20 mrad. For π+ mesons after 40 mrad, EPOS-LHC predicts higher yield as compared to EPOS 1.99 and QGSJETII-04 while EPOS-LHC and EPOS 1.99 give similar behavior in these two intervals. However, for π‑ mesons EPOS-LHC and EPOS 1.99 give similar behavior in these two intervals. For of K± mesons, QGSJETII-04 model gives higher predictions in all cases from 0-300 mrad, while EPOS 1.99 and EPOS-LHC show similar distributions. In case of protons, all models give similar distribution but this is not true for antiproton. All models are in good agreement for p > 20 GeV/c. EPOS 1.99 produce lower yield compared to the other two models from 60-360 mrad polar angle interval.

  11. Absorbed doses for patients undergoing panoramic radiography, cephalometric radiography and CBCT

    Directory of Open Access Journals (Sweden)

    Małgorzata Wrzesień

    2017-10-01

    Full Text Available Objectives: Contemporary dental radiology offers a wide spectrum of imaging methods but it also contributes to an increase in the participation of dental radiological diagnosis in the patient’s exposure to ionizing radiation. The aim of this study is to determine the absorbed doses of the brain, spinal column, thyroid and eye lens for patients during panoramic radiography, cephalometric radiography and cone beam computed tomography (CBCT. Material and Methods: The thermoluminescent dosimetry and anthropomorphic phantom was used for measuring the doses. The 15 panoramic, 4 cephalometric and 4 CBCT exposures were performed by placing high-sensitivity thermoluminescent detectors (TLD in 18 anatomical points of the phantom. Results: The maximum absorbed dose recorded during performed measurements corresponds to the point representing the brainstem and it is 10 mGy. The dose value recorded by the TLD placed in the thyroid during CBCT imaging in relation to the panoramic radiography differs by a factor of 13.5. Conclusions: Cone beam computed tomography, in comparison with panoramic or cephalometric imaging technique, provides higher radiation doses to the patients. Int J Occup Med Environ Health 2017;30(5:705–713

  12. Digital luminescent radiography: A substitute for conventional chest radiography?

    International Nuclear Information System (INIS)

    Neufang, K.F.R.; Krug, B.; Lorenz, R.; Steinbrich, W.

    1990-01-01

    The image quality of digital luminescent radiography (DLR) is sufficient for routine biplane chest radiography and for follow-up studies of heart size, pulmonary congestion, coin lesions, infiltrations, atelectasis, pleural effusions, and mediastinal and hilar lymph node enlargement. Chest radiography in the intensive care unit may in most cases be performed using the DLR technique. there is no need for repeat shots because of incorrect exposure, and the position of catheters, tubes, pacemakers, drains and artificial heart valves, the mediastinum, and the retrocardiac areas of the left lung are more confidently assessed on the edge-enhanced DLR films than on conventional films. Nevertheless, DLR is somewhat inferior to conventional film-screen radiography of the chest as it can demonstrate or rule out subtle pulmonary interstitial disease less confidently. There is no reduction of radiation exposure of the chest in DLR compared with modern film-screen systems. As a consequence, DLR is presently not in a position to replace traditional film-screen radiography of the chest completely. (orig.) [de

  13. Heavy-ion radiography

    International Nuclear Information System (INIS)

    Fabrikant, J.I.; Tobias, C.A.; Holley, W.R.; Benton, E.V.; Woodruff, K.H.; MacFarland, E.W.

    1983-01-01

    High energy, heavy-ion beams offer superior discrimination of tissue electron densities at very low radiation doses. This characteristic has potential for diagnostic medical imaging of neoplasms arising in the soft tissues and organs because it can detect smaller inhomogeneities than x rays. Heavy-ion imaging may also increase the accuracy of cancer radiotherapy planning involving use of accelerated charged particles. In the current physics research program of passive heavy-ion imaging, critical modulation transfer function tests are being carried out in heavy-ion projection radiography and heavy-ion computerized tomography. The research goal is to improve the heavy-ion imaging method until it reaches the limits of its theoretical resolution defined by range straggling, multiple scattering, and other factors involved in the beam quality characteristics. Clinical uses of the imaging method include the application of heavy-ion computerized tomography to heavy-ion radiotherapy planning, to the study of brain tumors and other structures of the head, and to low-dose heavy-ion projection mammography, particularly for women with dense breasts where other methods of diagnosis fail. The ions used are primarily 300 to 570 MeV/amu carbon and neon ions accelerated at the Lawrence Berkeley Laboratory Bevalac

  14. Comparison of proton and phosphorous ion implantation-induced intermixing of InAs/InP quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Barik, S; Tan, H H; Jagadish, C [Department of Electronic Materials Engineering, Research School of Physical Sciences and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia)

    2007-05-02

    We report and compare proton and phosphorous ion implantation-induced intermixing of InAs/InP quantum dots (QDs). After ion implantation at 20-300 deg. C, the QDs are rapid thermally annealed at 850 deg. C for 30 s. Proton implantation induces less energy shift than P ion implantation for a given concentration of atomic displacements due to the more efficient dynamic annealing of the defects created by protons. The implantation-induced energy shift reaches a maximum value of about 260 meV for a dose of 5 x 10{sup 12} ions cm{sup -2} in the P ion implanted QDs, which also show narrower PL linewidths compared to the proton implanted QDs. We also report the effects of an InGaAs top cap layer on the ion implantation-induced QD intermixing and show that defect production and annihilation processes evolve differently in InGaAs and InP layers and vary with the implantation temperature. When the implantation is performed at higher temperatures, the energy shift of the P ion implanted QDs capped with an InP layer increases due to the reduction in larger defect cluster formation at higher temperatures, while the energy shift of the proton implanted QDs decreases due to increased dynamic annealing irrespective of their cap layers.

  15. Detection of micro calcifications in breast specimen by 4-fold DIMA direct magnification radiography compared to 1.5-fold conventional magnification radiography

    International Nuclear Information System (INIS)

    Grunert, J.H.; Borchert, B.; Farber, A.; Gmelin, E.

    1999-01-01

    Aims of the study: The purpose of this study was to investigate the efficacy of 4-fold magnification breast specimen radiography (direct magnification, DIMA) compared to conventional 1.5-fold magnification radiography in evaluating the presence of absence of carcinoma at the surgical margins by detection of microcalcification. Results: In 50 specimen 2821 (1305 within 3 mm distance to the margins) microcalcifications were detected with the DIMA mammography technique compared to 1608 (446) microcalcifications with the conventional technique. This increased detection rate by DIMA-magnetification radiography was accompanied by a decreased specificity in comparison to the conventional magnification radiography (33,3% DIMA versus 83,3% conventional) regarding the evaluation of presence or absence of carcinoma at the surgical margins. Differentiating the microcalcifications into calcifications belonging to the suspicious cluster and those that are located outside the cluster led to an increase in specificity (83,3% DIMA versus 100% conventional). Conclusions: The efficacy of breast specimens radiography in evaluating the presence or absence of carcinoma at the surgical margins by detection of microcalcification is not improved by 4-fold magnification radiography (direct magnification, DIMA) compared to conventional 1.5-fold magnification radiography due to an increase in false-positive results. Analysis of the attachement of the microcalcifications to the cluster can improve the specificity. (orig.) [de

  16. Proton diffraction

    International Nuclear Information System (INIS)

    Den Besten, J.L.; Jamieson, D.N.; Allen, L.J.

    1998-01-01

    The Lindhard theory on ion channeling in crystals has been widely accepted throughout ion beam analysis for use in simulating such experiments. The simulations use a Monte Carlo method developed by Barret, which utilises the classical 'billiard ball' theory of ions 'bouncing' between planes or tubes of atoms in the crystal. This theory is not valid for 'thin' crystals where the planes or strings of atoms can no longer be assumed to be of infinite proportions. We propose that a theory similar to that used for high energy electron diffraction can be applied to MeV ions, especially protons, in thin crystals to simulate the intensities of transmission channeling and of RBS spectra. The diffraction theory is based on a Bloch wave solution of the Schroedinger equation for an ion passing through the periodic crystal potential. The widely used universal potential for proton-nucleus scattering is used to construct the crystal potential. Absorption due to thermal diffuse scattering is included. Experimental parameters such as convergence angle, beam tilt and scanning directions are considered in our calculations. Comparison between theory and experiment is encouraging and suggests that further work is justified. (authors)

  17. A Comparison of Molecular and Histopathological Changes in Mouse Intestinal Tissue Following Whole-Body Proton- or Gamma-Irradiation

    Science.gov (United States)

    Purgason, Ashley; Mangala, Lingegowda; Zhang, Ye; Hamilton, Stanley; Wu, Honglu

    2010-01-01

    There are many consequences following exposure to the space radiation environment which can adversely affect the health of a crew member. Acute radiation syndrome (ARS) involving nausea and vomiting, damage to radio-sensitive tissue such as the blood forming organs and gastrointestinal tract, and cancer are some of these negative effects. The space radiation environment is ample with protons and contains gamma rays as well. Little knowledge exists to this point, however, regarding the effects of protons on mammalian systems; conversely several studies have been performed observing the effects of gamma rays on different animal models. For the research presented here, we wish to compare our previous work looking at whole-body exposure to protons using a mouse model to our studies of mice experiencing whole-body exposure to gamma rays as part of the radio-adaptive response. Radio-adaptation is a well-documented phenomenon in which cells exposed to a priming low dose of radiation prior to a higher dose display a reduction in endpoints like chromosomal aberrations, cell death, micronucleus formation, and more when compared to their counterparts receiving high dose-irradiation only. Our group has recently completed a radio-adaptive experiment with C57BL/6 mice. For both this study and the preceding proton research, the gastrointestinal tract of each animal was dissected four hours post-irradiation and the isolated small intestinal tissue was fixed in formalin for histopathological examination or snap-frozen in liquid nitrogen for RNA isolation. Histopathologic observation of the tissue using standard H&E staining methods to screen for morphologic changes showed an increase in apoptotic lesions for even the lowest doses of 0.1 Gy of protons and 0.05 Gy of gamma rays, and the percentage of apoptotic cells increased with increasing dose. A smaller percentage of crypts showed 3 or more apoptotic lesions in animals that received 6 Gy of gamma-irradiation compared to mice

  18. Portable digital electronic radiography system

    International Nuclear Information System (INIS)

    Sawicka, B.D.

    1995-01-01

    Radiography is a standard nondestructive technique in the industrial testing of materials and components. It is routinely used during the construction, maintenance and repair of nuclear plants. Traditionally, radiography is performed using photographic film (film radiography, FR). Recent developments in solid-state area imaging radiation detectors, miniature electronics and computer software/hardware techniques have brought electronic alternatives to FR. In recent years various electronic radiography (ER) techniques have served as alternatives to FR, these proved beneficial in some applications. While originally developed to provide real time imaging, ER may offer other advantages over FR, depending on the application. Work was undertaken at CRL to review progress in ER techniques and evaluate the possibility of constructing a portable DER (digital electronic radiography) system, for the inspection of power plant components. A suitable DER technique has been developed and a proof of principle portable system constructed. As this paper demonstrates, a properly designed ER system can be small and compact, while providing radiographic examination with acceptable image quality and the benefits of ER imaging. The CRL DER system can operate with radioactive sources typical of FR. While it does not replace FR, our DER system is expected to be beneficial in specific applications for Candu maintenance, reducing cost, labour and time. Practical, cost saving applications of this system are expected to include valve monitoring and foreign object location during maintenance at Candu reactors

  19. Computed radiography in NDT application

    International Nuclear Information System (INIS)

    Deprins, Eric

    2004-01-01

    Computed Radiography, or digital radiography by use of reusable Storage Phosphor screens, offers a convenient and reliable way to replace film. In addition to the reduced cost on consumables, the return on investment of CR systems is strongly determined by savings in exposure time, processing times and archival times. But also intangible costs like plant shutdown, environment safety and longer usability of isotopes are increasingly important when considering replacing film by Storage Phosphor systems. But mote than in traditional radiography, the use of digital images is a trade-off between the speed and the required quality. Better image quality is obtained by longer exposure times, slower phosphor screens and higher scan resolutions. Therefore, different kinds of storage phosphor screens are needed in order to cover every application. Most operations have the data, associated with the tests to be performed, centrally stored in a database. Using a digital radiography system gives not only the advantages of the manipulation of digital images, but also the digital data that is associated with it. Smart methods to associate cassettes and Storage screens with exposed images enhance the workflow of the NDT processes, and avoid human error. Automated measurements tools increase the throughput in different kinds of operations. This paper gives an overview of the way certain operations have decided to replace film by Computed Radiography, and what the major benefits for them have been.

  20. Digital Radiography in Kenya today

    International Nuclear Information System (INIS)

    Omenta, E.N.

    2006-01-01

    Its nearly one year and a half since digital imaging/radiography was introduced in Kenya mainly in Nairobi. the technology is becoming an increasingly effective and acceptable modality of producing radiographs from the traditional conventional radiography in use to date. the digital radiography offers numerous advantages that have been noted for the short period over the conventional way. For instance radiographs are produced in real time (less than 3 minutes), by so doing the technology has eliminated the wait for the processing period. the radiation exposure to the patient under the radiological examination is reduced as much as 90% from the traditional conventional film taking. The cost, labour and record-keeping necessary to maintain a chemical processor and darkroom operations are as well eliminated. The cost of purchasing and disposing of film wastes/darkroom processing chemicals, which are environmentally hazardous, also become unnecessary.digital radiography technology makes the digital images comparable to other images on the screen at that instant making both the patient and the clinician easily access images when needed. digital receptors have also replaced the cassette containing intensifying screens and film that is used in conventional radiography

  1. Computed radiography for breast cancer

    International Nuclear Information System (INIS)

    Yamada, Tatsuya; Muramatsu, Yukio

    1990-01-01

    In order to evaluate the possibility of using computed radiographic mammography in mass surveys of the breast, we have retrospectively examined 71 breast cancer lesions in 71 patients using computed radiographic and conventional non-screen mammographies and have carried out comparative studies on tumor detection rate and calcification. A 95.8% detection rate was obtained for the tumor image (n 71) using computed radiography (CR) and one of 93.0% using non-screen techniques. Three lesions remained undetected by either study. A 100% detection rate was obtained for calcification associated with cancer (n 33) from each method. No significant differences in either detection rate or calcification were seen between the two images. On the other hand, the ability to recognize tumor images (n 66) was as follows; CR superior to non-screen radiography in 53 lesions (80.3%), equal in eight lesions (12.1%) and inferior in five lesions (7.6%). For the calcification images (n 18), CR was superior to non-screen radiography in all 18 lesions. Obviously, CR gives better results than non-screen radiography. Furthermore, an adequate image can be obtained using CR even although the X-ray dosage is only a twentieth of that required for non-screen radiography. It can therefore be applied not only to mass surveys for breast cancer but also to routine clinical diagnoses. (author)

  2. Comparison of chest radiography and high-resolution computed tomography findings in early and low-grade coal worker's pneumoconiosis

    Energy Technology Data Exchange (ETDEWEB)

    Savranlar, A.; Altin, R.; Mahmutyazicioglu, K.; Ozdemir, H.; Kart, L.; Ozer, T.; Gundogdu, S. [Zonguldak Karaelmas University, Zonguldak (Turkey). Faculty of Medicine

    2004-08-01

    High-resolution computed tomography (HRCT) is more sensitive than chest X-ray (CXR) in the depiction of parenchymal abnormalities. The paper presents and compares CXR and HRCT findings in coal workers with and without early and low-grade coal worker's pneumoconiosis (CWP). 71 coal workers were enrolled in the study. HRCT's were graded according to Hosoda and Shida's Japanese classification. After grading, 67 workers with CXR profusion 0/0-2/2 were included in the study. Four patients with major opacity were excluded. Profusion 0/1 to 1/1 cases were accepted as early and profusion and 2/2 cases as low-grade pneumoconiosis. Discordance rate was found to be higher in the early pneumoconiosis cases with negative CXR than low-grade pneumoconiosis (60, 36 and 8%, respectively). When coal miners with normal CXR were evaluated by HRCT, six out of 10 cases were diagnosed as positive. In low-grade pneumoconiosis group, the number of patients with positive CXR but negative HRCT were low in comparison to patients with CXR negative and early pneumoconiosis findings. Most of the CXR category 0 patients (10/16) were diagnosed as category 1 by HRCT. Eleven cases diagnosed as CXR category 1 were diagnosed as category 0 (7/11) and category 2 (4/11) by HRCT. In CXR category 2 (eight cases), there were four cases diagnosed as category 1 by HRCT. Overall, discordance between CXR and HRCT was high, especially for CXR negative and early pneumoconiosis cases. The role of CXR in screening coal workers to detect early pneumoconiosis findings should be questioned. The authors suggest using HRCT as a standard screening method instead of CXR to distinguish between normal and early pneumoconiosis.

  3. Industrial Radiography | Radiation Protection | US EPA

    Science.gov (United States)

    2017-08-07

    Manufacturers use a method called industrial radiography to check for cracks or flaws in materials. Radiation is used in industrial radiography to show problems not visible from the outside without damaging the material.

  4. Pediatric radiation dose management in digital radiography

    International Nuclear Information System (INIS)

    Neitzel, U.

    2004-01-01

    Direct digital radiography (DR) systems based on flat-panel detectors offer improved dose management in pediatric radiography. Integration of X-ray generation and detection in one computer-controlled system provides better control and monitoring

  5. Comparison of the image quality of digital radiography system and film screen system - Radiologist' rating of the visibility of normal anatomic - Structures in chest PA, Skull radiograph and K. U. B

    International Nuclear Information System (INIS)

    Song, Kounn Sik; Kim, Young Goo; Lee, Jong Beum; Kim, Kun Sang

    1987-01-01

    Digital image acquisition and display is widely used in computed tomography, ultrasonography, digital subtraction angiography, nuclear medicine and magnetic resonance image. But most of the radiological examinations performed in radiology department are made by using conventional system. The development of the digital radiography system is essential if totally digitized radiology department is desired. The advantages of digitizing the radiographic information are usually discussed in terms of PACS (picture archiving and communication system), furthermore there are many other advantages such as contrast modification, spatial filtering subtraction and superimposition of the images through the image processing by computer. Currently several approaches are under development or in clinical use, the most promising approach is the use of imaging plate composed of photostimulate phosphors such as barium fluorohalide crystal read with a He-Ne laser to produce digital radiographic images. Another promising approach is scan projection radiography. The authors performed the clinical study of comparing the image qualities of digital radiography system using scanning laser luminescence (FCR) and conventional film-screen system in chest PA, skull radiography and K. U. B. in terms of the visibility of the normal anatomic structure rating those (qualities) on a scale of 0 to 3 and obtained the following results. Normal contrast digital images are comparable to conventional film-screen images, but the images of high frequency enhancement is far superior to conventional film-screen especially in peripherally located structures such as skin, subcutaneous fat, musculoskeletal systems, nasal bone, inner and outer table of the skull including the diploic space, paranasal sinuses, nasopharynx and larynx, trachea and main bronchi, mediastinal structures, retrocardiac and subphrenic vascular markings. Another promising aspects of digital radiography system is its wide exposure latitude and

  6. TU-FG-BRB-02: The Impact of Using Dual-Energy CT for Determining Proton Stopping Powers: Comparison Between Theory and Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Baer, E; Jee, K [Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Zhang, R; Yang, K; Sharp, G; Liu, B [Massachusetts General Hospital, Boston, MA (United States); Lalonde, A [University of Montreal, Montreal, QC (Canada); Royle, G [University College London, London, London (United Kingdom); Bouchard, H [Universite de Montreal, Montreal, QC (Canada); Lu, H [Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States)

    2016-06-15

    Purpose: To evaluate the clinical performance of dual-energy CT (DECT) in determining proton stopping power ratios (SPR) and demonstrate advantages over conventional single-energy CT (SECT). Methods: SECT and DECT scans of tissue-equivalent plastics as well as animal meat samples are performed with a Siemens SOMATOM Definition Flash. The methods of Schneider et al. (1996) and Bourque et al. (2014) are used to determine proton SPR on SECT and DECT images, respectively. Waterequivalent path length (WEPL) measurements of plastics and tissue samples are performed with a 195 MeV proton beam. WEPL values are determined experimentally using the depth-dose shift and dose extinction methods. Results: Comparison between CT-based and experimental WEPL is performed for 12 tissue-equivalent plastic as well as 6 meat boxes containing animal liver, kidney, heart, stomach, muscle and bones. For plastic materials, results show a systematic improvement in determining SPR with DECT, with a mean absolute error of 0.4% compared to 1.7% for SECT. For the meat samples, preliminary results show the ability for DECT to determine WEPL with a mean absolute value of 1.1% over all meat boxes. Conclusion: This work demonstrates the potential in using DECT for determining proton SPR with plastic materials in a clinical context. Further work is required to show the benefits of DECT for tissue samples. While experimental uncertainties could be a limiting factor to show the benefits of DECT over SECT for the meat samples, further work is required to adapt the DECT formalism in the context of clinical use, where noise and artifacts play an important role.

  7. TU-FG-BRB-02: The Impact of Using Dual-Energy CT for Determining Proton Stopping Powers: Comparison Between Theory and Experiments

    International Nuclear Information System (INIS)

    Baer, E; Jee, K; Zhang, R; Yang, K; Sharp, G; Liu, B; Lalonde, A; Royle, G; Bouchard, H; Lu, H

    2016-01-01

    Purpose: To evaluate the clinical performance of dual-energy CT (DECT) in determining proton stopping power ratios (SPR) and demonstrate advantages over conventional single-energy CT (SECT). Methods: SECT and DECT scans of tissue-equivalent plastics as well as animal meat samples are performed with a Siemens SOMATOM Definition Flash. The methods of Schneider et al. (1996) and Bourque et al. (2014) are used to determine proton SPR on SECT and DECT images, respectively. Waterequivalent path length (WEPL) measurements of plastics and tissue samples are performed with a 195 MeV proton beam. WEPL values are determined experimentally using the depth-dose shift and dose extinction methods. Results: Comparison between CT-based and experimental WEPL is performed for 12 tissue-equivalent plastic as well as 6 meat boxes containing animal liver, kidney, heart, stomach, muscle and bones. For plastic materials, results show a systematic improvement in determining SPR with DECT, with a mean absolute error of 0.4% compared to 1.7% for SECT. For the meat samples, preliminary results show the ability for DECT to determine WEPL with a mean absolute value of 1.1% over all meat boxes. Conclusion: This work demonstrates the potential in using DECT for determining proton SPR with plastic materials in a clinical context. Further work is required to show the benefits of DECT for tissue samples. While experimental uncertainties could be a limiting factor to show the benefits of DECT over SECT for the meat samples, further work is required to adapt the DECT formalism in the context of clinical use, where noise and artifacts play an important role.

  8. Quantification of the Relative Biological Effectiveness for Ion Beam Radiotherapy: Direct Experimental Comparison of Proton and Carbon Ion Beams and a Novel Approach for Treatment Planning

    International Nuclear Information System (INIS)

    Elsaesser, Thilo; Weyrather, Wilma K.; Friedrich, Thomas; Durante, Marco; Iancu, Gheorghe; Kraemer, Michael; Kragl, Gabriele; Brons, Stephan; Winter, Marcus; Weber, Klaus-Josef; Scholz, Michael

    2010-01-01

    Purpose: To present the first direct experimental in vitro comparison of the biological effectiveness of range-equivalent protons and carbon ion beams for Chinese hamster ovary cells exposed in a three-dimensional phantom using a pencil beam scanning technique and to compare the experimental data with a novel biophysical model. Methods and Materials: Cell survival was measured in the phantom after irradiation with two opposing fields, thus mimicking the typical patient treatment scenario. The novel biophysical model represents a substantial extension of the local effect model, previously used for treatment planning in carbon ion therapy for more than 400 patients, and potentially can be used to predict effectiveness of all ion species relevant for radiotherapy. A key feature of the new approach is the more sophisticated consideration of spatially correlated damage induced by ion irradiation. Results: The experimental data obtained for Chinese hamster ovary cells clearly demonstrate that higher cell killing is achieved in the target region with carbon ions as compared with protons when the effects in the entrance channel are comparable. The model predictions demonstrate agreement with these experimental data and with data obtained with helium ions under similar conditions. Good agreement is also achieved with relative biological effectiveness values reported in the literature for other cell lines for monoenergetic proton, helium, and carbon ions. Conclusion: Both the experimental data and the new modeling approach are supportive of the advantages of carbon ions as compared with protons for treatment-like field configurations. Because the model predicts the effectiveness for several ion species with similar accuracy, it represents a powerful tool for further optimization and utilization of the potential of ion beams in tumor therapy.

  9. Basic research for developing the quantitative neutron radiography

    International Nuclear Information System (INIS)

    Tamaki, Masayoshi; Ikeda, Yasushi; Ohkubo, Kohei; Tasaka, Kanji; Yoneda, Kenji; Fujine, Shigenori.

    1992-01-01

    This investigation concerns the basic research and development on quantitative neutron radiography by using a honeycomb collimator which reduces the effect due to scattered neutrons in objective matter. On the observation of the hydrogenate materials such as metal hydrides, water and hydrocarbons by neutron radiography, scattered neutrons from these objectives make the quantitativeness of the neutron radiographic image lower grade. In order to improve the quantitativeness of the image, a honeycomb collimator, which is a honeycomb structure of neutron absorbing material, was introduced to the conventional neutron radiography system. By setting the neutron-absorbing honeycomb collimator between objective and imaging system, neutrons scattered in the objective were absorbed by the honeycomb material and attenuated before coming to the imaging system, but neutrons which were transmitted the objective sample without any interaction reached the imaging system and formed the image of the sample. As the image by purely transmitted neutrons is intrinsic due to the neutronic character of the sample, the image data give the quantitative information. In the present experiment, aluminum honeycomb which was coated with boron nitride was prepared and used in order to image the standard stepwise samples for the evaluation of the quantitative grade of the newly proposed neutron radiography method. From the comparison between macroscopic total cross section and the attenuation coefficient of the thermal neutron for aluminum, copper and hydrocarbons, it was confirmed that they were fairly consistent each other. It can be concluded that the newly proposed neutron radiography method using the neutron-absorbing honeycomb collimator for the elimination of the scattered neutrons improves remarkably the quantitativeness of the neutron radiography technique. (author)

  10. Dosimetric Comparison and Potential for Improved Clinical Outcomes of Paediatric CNS Patients Treated with Protons or IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Armoogum, Kris S., E-mail: kris.armoogum@nhs.net [Department of Radiotherapy Physics, Royal Derby Hospital, Derby Hospitals NHS Foundation Trust, Uttoxeter Road, Derby DE22 3NE (United Kingdom); Thorp, Nicola [The Clatterbridge Cancer Centre NHS Foundation Trust, Clatterbridge Road, Bebington, Wirral CH63 4JY (United Kingdom)

    2015-04-28

    Background: We compare clinical outcomes of paediatric patients with CNS tumours treated with protons or IMRT. CNS tumours form the second most common group of cancers in children. Radiotherapy plays a major role in the treatment of many of these patients but also contributes to late side effects in long term survivors. Radiation dose inevitably deposited in healthy tissues outside the clinical target has been linked to detrimental late effects such as neurocognitive, behavioural and vascular effects in addition to endocrine abnormalities and second tumours. Methods: A literature search was performed using keywords: protons, IMRT, CNS and paediatric. Of 189 papers retrieved, 10 were deemed relevant based on title and abstract screening. All papers directly compared outcomes from protons with photons, five papers included medulloblastoma, four papers each included craniopharyngioma and low grade gliomas and three papers included ependymoma. Results: This review found that while proton beam therapy offered similar clinical target coverage, there was a demonstrable reduction in integral dose to normal structures. Conclusions: This in turn suggests the potential for superior long term outcomes for paediatric patients with CNS tumours both in terms of radiogenic second cancers and out-of-field adverse effects.

  11. Dosimetric Comparison and Potential for Improved Clinical Outcomes of Paediatric CNS Patients Treated with Protons or IMRT

    Directory of Open Access Journals (Sweden)

    Kris S. Armoogum

    2015-04-01

    Full Text Available Background: We compare clinical outcomes of paediatric patients with CNS tumours treated with protons or IMRT. CNS tumours form the second most common group of cancers in children. Radiotherapy plays a major role in the treatment of many of these patients but also contributes to late side effects in long term survivors. Radiation dose inevitably deposited in healthy tissues outside the clinical target has been linked to detrimental late effects such as neurocognitive, behavioural and vascular effects in addition to endocrine abnormalities and second tumours. Methods: A literature search was performed using keywords: protons, IMRT, CNS and paediatric. Of 189 papers retrieved, 10 were deemed relevant based on title and abstract screening. All papers directly compared outcomes from protons with photons, five papers included medulloblastoma, four papers each included craniopharyngioma and low grade gliomas and three papers included ependymoma. Results: This review found that while proton beam therapy offered similar clinical target coverage, there was a demonstrable reduction in integral dose to normal structures. Conclusions: This in turn suggests the potential for superior long term outcomes for paediatric patients with CNS tumours both in terms of radiogenic second cancers and out-of-field adverse effects.

  12. Comparison between proton transfer reaction mass spectrometry and near infrared spectroscopy for the authentication of Brazilian coffee

    NARCIS (Netherlands)

    Monteiro, Pablo Inocêncio; Santos, Jânio Sousa; Alvarenga Brizola, Vitor Rafael; Pasini Deolindo, Carolina Turnes; Koot, Alex; Boerrigter-Eenling, Rita; Ruth, van Saskia; Georgouli, Konstantia; Koidis, Anastasios; Granato, Daniel

    2018-01-01

    In this study, proton-transfer reaction mass spectrometry (PTR-MS) and near-infrared spectroscopy (NIRS) were compared for the authentication of geographical and farming system origins of Brazilian coffees. For this purpose, n = 19 organic (ORG) and n = 26 conventional (CONV) coffees from

  13. Performance tests and comparison of microdosimetric measurements with four tissue-equivalent proportional counters in scanning proton therapy

    Czech Academy of Sciences Publication Activity Database

    Farah, J.; De Saint-Hubert, M.; Mojzeszek, N.; Chiriotti, S.; Gryzinski, M.; Ploc, Ondřej; Trompier, F.; Turek, Karel; Vanhavere, F.; Olko, P.

    2017-01-01

    Roč. 96, JAN (2017), s. 42-52 ISSN 1350-4487 EU Projects: European Commission(XE) 662287 - CONCERT Institutional support: RVO:61389005 Keywords : tissue-equivalent proportional counters * microdosimetry * proton therapy * stray neutrons and prothons Subject RIV: JF - Nuclear Energetics OBOR OECD: Nuclear related engineering Impact factor: 1.442, year: 2016

  14. Image Acquisition and Quality in Digital Radiography.

    Science.gov (United States)

    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. ©2016 American Society of Radiologic Technologists.

  15. Dose comparison according to Smooth Thickness application of Range compensator during proton therapy for brain tumor patient

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tase Woan; Kim, Dae Woong; Kim, Jae Weon; Jeong, Kyeong Sik [Proton Therapy Center, National Cancer Center, Goyang (Korea, Republic of)

    2016-12-15

    Range Compensator used for proton therapy compensates the proton beam dose which delivers to the normal tissues according to the Target's Distal Margin dose. We are going to check the improvement of dose on the target part by comparing the dose of PTV and OAR according to applying in different method of Smooth Thickness of Range Compensator which is used in brain tumor therapy. For 10 brain tumor patients taking proton therapy in National Cancer Center, Apply Smooth Thickness applied in Range Compensator in order from one to five by using Compensator Editor of Eclipse Proton Planning System(Version 10.0, Varian, USA). The therapy plan algorithm used Proton Convolution Superposition(version 8.1.20 or 10.0.28), and we compared Dmax, Dmin, Homogeneity Index, Conformity Index and OAR dose around tumor by applying Smooth Thickness in phase. When Smooth Thickness was applied from one to five, the Dmax of PTV was decreased max 4.3%, minimum at 0.8 and average of 1.81%. Dmin increased max 1.8%, min 1.8% and average. Difference between max dose and minimum dose decreased at max 5.9% min 1.4% and average 2.6%. Homogeneity Index decreased average of 0.018 and Conformity Index didn't had a meaningful change. OAR dose decreased in Brain Stem at max 1.6%, min 0.1% and average 0.6% and in Optic Chiasm max 1.3%, min 0.3%, and average 0.5%. However, patient C and patient E had an increase each 0.3% and 0.6%. Additionally, in Rt. Optic Nerve, there was a decrease at max 1.5%, min 0.3%, and average 0.8%, however, patient B had 0.1% increase. In Lt. Optic Nerve, there was a decrease at max 1.8%, min 0.3%, and average 0.7%, however, patient H had 0.4 increase. As Smooth Thickness of Range Compensator which is used as the proton treatment for brain tumor patients is applied in stages, the resolution of Compensator increased and as a result the most optimized amount of proton beam dose can be delivered. This is considered to be able to irradiate the equal amount at PTV and

  16. Neutron radiography for nondestructive testing

    International Nuclear Information System (INIS)

    John, J.

    1979-01-01

    Neutron radiography is similar to X-ray inspection in that both depend upon use of radiation that penetrates some materials and is absorbed by others to provide a contrast image of conditions not readily available for visual inspection. X-rays are absorbed by dense materials, such as metals, whereas neutrons readily penetrate metals, but are absorbed by materials containing hydrogen. The neutron radiography has been successfully applied to a number of inspection situations. These include the inspection of explosives, advanced composites, adhesively bonded structures and a number of aircraft engine components. With the availability of Californium-252, it has become feasible to construct mobile neutron radiography systems suitable for field use. Such systems have been used for in-situ inspection of flight line aircraft, particularly to locate and measure hidden corrosion

  17. Neutron radiography of fuel pins

    International Nuclear Information System (INIS)

    Jackson, C.N. Jr.; Powers, H.G.; Burgess, C.A.

    1975-01-01

    Neutron radiography performed with a reactor source has been shown to be a superior radiographic method for the examination of unirradiated mixed oxide fuel pins at the Hanford Engineering Development Laboratory. Approximately 1,700 fuel pins were contained in a sample that demonstrated the capability of the method for detecting laminations, structural flaws, fissile density variation, hydrogenous inclusions and voids in assembled fuel pins. The nature, extent, and importance of the detected conditions are substantiated by gamma autoradiography and by destructive analysis employing alpha autoradiography, electron microprobe and visual inspection. Also, a series of radiographs illustrate the response of neutron radiography as compared to low voltage and high voltage x-ray and gamma source Iridium 192 radiography. (U.S.)

  18. Clinical Applications of Reverse Panoramic Radiography

    Directory of Open Access Journals (Sweden)

    Sujatha S Reddy

    2011-09-01

    Full Text Available The essence of oral and maxil-lofacial radiology is not only to be an important tool in the diagnostic assessment of dental patients but also to equip the clinician with the ability to interpret images of certain maxillocraniofacial structures of importance to dental, medical and surgical practices. Although combinations of several conven-tional x-ray projections can be adequate in a number of clinical situations, radiographic assessment of certain craniofacial structures some-times needs to be facilitated by other imaging modalities. A not-so-recent development called reverse panoramic radiography may be a useful adjuvant to such a situation, at least in the near future. It is essentially a technique where the patient is placed backwards in the panoramic machine in a reverse position in such a way that x-ray beam is directed through the patient’s face and the exit beam then passes through the patient’s head on the opposite side where it is captured on the receptor. The following manuscript is an attempt to throw light on this technique and the impact it may have on dental, medical and surgical practices. The advantages and disadvantages of reverse panoramic radiography and it’s comparison to conventional panoramic radiographs and other skull views are also dis-cussed.

  19. Neutron radiography working group test programme

    International Nuclear Information System (INIS)

    Domanus, J.C.

    1989-03-01

    Scope and results of the Euratom Neutron Radiography Working Group Test Program are described. Seven NR centers from six European Community countries have performed this investigation using eleven NR facilities. Four test items were neutron radiographed using 30 different film/converter combinations. From film density measurements neutron beam components were determined. Radiographic sensitivity was assessed from visual examinations of the radiographs. About 25,000 dimensional measurements were made and were used for the assessment of accuracies of dimensional measurements from neutron radiographs. The report gives a description of the test items used for the Test Program, the film density and dimensional measurements, and concentrates on the assessment of the measuring results. The usefulness of the beam purity and sensitivity indicators was assessed with the conclusion that they are not suitable for neutron radiography of nuclear reactor fuel. Ample information is included in the report about measuring accuracies which can be reached in dimensional measurements of fuel pins. After a general comparison of measuring accuracies is discussed. Results from different NR facilities are treated separately as are the different kinds of dimensions of the fuel pins. Finally human and instrument factors are discussed. After presenting final conclusions (which take into account the above-mentioned factors) results of other investigations about dimensional measurements are shortly reviewed

  20. Imaging characteristics in rotational panoramic radiography

    International Nuclear Information System (INIS)

    Sanderink, G.C.H.

    1987-01-01

    This study is concerned with imaging quality in rotational panoramic radiography. This imaging technique records an image of a curved layer within the object radiographed. The shape of this layer normally corresponds with the average form of the dental arch. In the centre of the layer a plane can be found which is depicted with a minimum of unsharpness. Unsharpness increases and the horizontal magnification changes as distance increases from that central plane. The image quality of the layer has been analyzed with the use of mathematical models to estimate the performance of the radiographic diagnostic system. Despite the application of these increasingly sophisticated models the question remains: will the results of the calculations based on these models adequately predict the diagnostic effectiveness of this type of imaging system? In this study a comparison is made between the theoretically determined quality of the system and the diagnostic quality using the observer as a measuring instrument. Experiments were carried out to measure the total unsharpness occurring in rotational panoramic radiography. 116 refs.; 114 figs.; 54 tabs

  1. Neutron-induced alpha radiography

    International Nuclear Information System (INIS)

    Pereira, Marco Antonio Stanojev

    2008-01-01

    A new radiography technique to inspect thin samples was developed. Low energy alpha particles, generated by a boron based screen under thermal neutron irradiation, are used as penetrating radiation. The solid state nuclear track detector CR-39 has been used to register the image. The interaction of the α - particles with the CR-39 gives rise to damages which under an adequate chemical etching became tracks the basic units forming the image. A digital system was developed for data acquisition and data analysis as well as for image processing. The irradiation and etching conditions to obtain the best radiography are 1,3 hours and 25 minutes at 70 deg C respectively. For such conditions samples having 10 μm in thickness can be inspected with a spatial resolution of 32 μm. The use of the digital system has reduced the time spent for data acquisition and data analysis and has improved the radiography image visualization. Furthermore, by using the digital system, it was possible to study several new parameters regarding the tracks which are very important to understand and study the image formation theory in solid state nuclear track detectors, the one used in this thesis. Some radiography images are also shown which demonstrate the potential of the proposed radiography technique. When compared with the other radiography techniques already in use to inspect thin samples, the present one developed in the present paper allows a smaller time to obtain the image, it is not necessary to handle liquid radioactive substances, the detector is insensitive to β, γ, X-ray and visible light. (author)

  2. Chest X-Ray (Chest Radiography)

    Science.gov (United States)

    ... Resources Professions Site Index A-Z X-ray (Radiography) - Chest Chest x-ray uses a very small dose ... Radiography? What is a Chest X-ray (Chest Radiography)? The chest x-ray is the most commonly performed diagnostic ...

  3. A range of equipment for dental radiography

    International Nuclear Information System (INIS)

    Bergman, G.P.M.; Clement, S.L.

    1980-01-01

    A brief review of the history of dental radiography is followed by a description of the latest Philips equipment, ranging from compact units for intra-oral radiography to advanced systems for panoramic techniques and skull radiography. The advantages of automatic exposure control and automatic film processing are also discussed. In conclusion, some probable future trends are forecast. (Auth.)

  4. Development of tungsten collimators for industrial radiography

    International Nuclear Information System (INIS)

    Varkey, P.A.; Verma, P.B.; Jayakumar, T.K.; Mammachan, M.K.

    2001-01-01

    Collimators are essential components of industrial radiography set up as it provides radiation safety to persons involved in the radiography work. A collimator with optimum design features also helps in reducing the scattered radiation which in turn results in radiographs having better sensitivity. This papers describes the salient design features of the tungsten collimators developed by the BRIT, for industrial radiography. (author)

  5. Radioisotopes - their applications in industrial radiography

    International Nuclear Information System (INIS)

    Rao, H.R.S.

    1977-01-01

    The nature of radioisotopes and their industrial applications with special reference to industrial radiography are outlined. The various aspects of industrial radiography such as source size, source containers, films, density of radiography, radiographic quality and applications are discussed in brief. (M.G.B.)

  6. Monte Carlo patient study on the comparison of prompt gamma and PET imaging for range verification in proton therapy

    Science.gov (United States)

    Moteabbed, M.; España, S.; Paganetti, H.

    2011-02-01

    The purpose of this work was to compare the clinical adaptation of prompt gamma (PG) imaging and positron emission tomography (PET) as independent tools for non-invasive proton beam range verification and treatment validation. The PG range correlation and its differences with PET have been modeled for the first time in a highly heterogeneous tissue environment, using different field sizes and configurations. Four patients with different tumor locations (head and neck, prostate, spine and abdomen) were chosen to compare the site-specific behaviors of the PG and PET images, using both passive scattered and pencil beam fields. Accurate reconstruction of dose, PG and PET distributions was achieved by using the planning computed tomography (CT) image in a validated GEANT4-based Monte Carlo code capable of modeling the treatment nozzle and patient anatomy in detail. The physical and biological washout phenomenon and decay half-lives for PET activity for the most abundant isotopes such as 11C, 15O, 13N, 30P and 38K were taken into account in the data analysis. The attenuation of the gamma signal after traversing the patient geometry and respective detection efficiencies were estimated for both methods to ensure proper comparison. The projected dose, PG and PET profiles along many lines in the beam direction were analyzed to investigate the correlation consistency across the beam width. For all subjects, the PG method showed on average approximately 10 times higher gamma production rates than the PET method before, and 60 to 80 times higher production after including the washout correction and acquisition time delay. This rate strongly depended on tissue density and elemental composition. For broad passive scattered fields, it was demonstrated that large differences exist between PG and PET signal falloff positions and the correlation with the dose distribution for different lines in the beam direction. These variations also depended on the treatment site and the

  7. TREAT neutron-radiography facility

    International Nuclear Information System (INIS)

    Harrison, L.J.

    1981-01-01

    The TREAT reactor was built as a transient irradiation test reactor. By taking advantage of built-in system features, it was possible to add a neutron-radiography facility. This facility has been used over the years to radiograph a wide variety and large number of preirradiated fuel pins in many different configurations. Eight different specimen handling casks weighing up to 54.4 t (60 T) can be accommodated. Thermal, epithermal, and track-etch radiographs have been taken. Neutron-radiography service can be provided for specimens from other reactor facilities, and the capacity for storing preirradiated specimens also exists

  8. Radiation protection in dental radiography

    International Nuclear Information System (INIS)

    Jozani, F.; Parnianpour, H.

    1976-08-01

    In considering the special provisions required in dental radiography, investigations were conducted in Iran. Radiation dose levels in dental radiography were found to be high. Patient exposure from intraoral radiographic examination was calculated, using 50kV X-ray. Thermoluminescent dosimeters were fastened to the nasion, eyes, lip, philtrum, thyroid, gonads and to the right and left of the supra-orbital, infra-orbital temporomandibular joints of live patients. The highest exposure value was for the lower lip. Recommendations concerning educational training and protection of staff and patients were included

  9. Use of radiography in archaeology

    International Nuclear Information System (INIS)

    Chetin, M.; Ekinci, Sh.; Aksu, M.

    2014-01-01

    Full text : Radiography is a versatile technique with many applications to archaeological and art historical artefacts. It can be used to assess the condition of objects before conservation treatment, to gain insight into materials used and methods of construction and to reveal the secrets of the embalmers art, hidden within mummified remains. X-ray radiography is an invaluable investigative technique that is non-destructive, quick and cost effective. The study described below covers the investigations of the archaeological artefacts in order to determine their corrosion conditions and production histories which are important for restoration, conservation, replica, dating and inventory works

  10. Educational aspects of industrial radiography

    International Nuclear Information System (INIS)

    Krishnamurthy, K.; Wamorkar, R.R.; Singh, G.

    1979-01-01

    The state of art of training and education in non-destructive testing in India, with special reference to industrial radiography is reviewed. Basic requirement of industry and potential of radioisotopes in industrial inspection are also described. Need for an organised training programme in industrial isotope radiography to exploit potentials for benefit of industry concurrent with the safety is stressed. A comprehensive training programme tailored to meet the needs of Indian industry is outlined. Benefits obtained from the course to the industry since the beginning of the training programme are briefly reviewed. (auth.)

  11. Radiological safety aspects of industrial radiography

    International Nuclear Information System (INIS)

    Hanekom, A.P.

    1983-01-01

    Industrial radiography and especially gamma-radiography, has established itself as a very powerful tool in non-destructive testing. Unfortunately there is an amount of risk attached to the use of industrial radiography. The primary causes of radiography accidents include: working conditions, equipment failure and lack of supervisory control. To alleviate the radiological risks involved with gamma-radiography, the Atomic Energy Corporation (AEC) has imposed various conditions for the possession, use, and conveyance of radioactive material. This includes personnel training and equipment specifications

  12. Experimental Comparison of Knife-Edge and Multi-Parallel Slit Collimators for Prompt Gamma Imaging of Proton Pencil Beams

    Science.gov (United States)

    Smeets, Julien; Roellinghoff, Frauke; Janssens, Guillaume; Perali, Irene; Celani, Andrea; Fiorini, Carlo; Freud, Nicolas; Testa, Etienne; Prieels, Damien

    2016-01-01

    More and more camera concepts are being investigated to try and seize the opportunity of instantaneous range verification of proton therapy treatments offered by prompt gammas emitted along the proton tracks. Focusing on one-dimensional imaging with a passive collimator, the present study experimentally compared in combination with the first, clinically compatible, dedicated camera device the performances of instances of the two main options: a knife-edge slit (KES) and a multi-parallel slit (MPS) design. These two options were experimentally assessed in this specific context as they were previously demonstrated through analytical and numerical studies to allow similar performances in terms of Bragg peak retrieval precision and spatial resolution in a general context. Both collimators were prototyped according to the conclusions of Monte Carlo optimization studies under constraints of equal weight (40 mm tungsten alloy equivalent thickness) and of the specificities of the camera device under consideration (in particular 4 mm segmentation along beam axis and no time-of-flight discrimination, both of which less favorable to the MPS performance than to the KES one). Acquisitions of proton pencil beams of 100, 160, and 230 MeV in a PMMA target revealed that, in order to reach a given level of statistical precision on Bragg peak depth retrieval, the KES collimator requires only half the dose the present MPS collimator needs, making the KES collimator a preferred option for a compact camera device aimed at imaging only the Bragg peak position. On the other hand, the present MPS collimator proves more effective at retrieving the entrance of the beam in the target in the context of an extended camera device aimed at imaging the whole proton track within the patient. PMID:27446802

  13. Experimental Comparison of Knife-Edge and Multi-Parallel Slit Collimators for Prompt Gamma Imaging of Proton Pencil Beams.

    Science.gov (United States)

    Smeets, Julien; Roellinghoff, Frauke; Janssens, Guillaume; Perali, Irene; Celani, Andrea; Fiorini, Carlo; Freud, Nicolas; Testa, Etienne; Prieels, Damien

    2016-01-01

    More and more camera concepts are being investigated to try and seize the opportunity of instantaneous range verification of proton therapy treatments offered by prompt gammas emitted along the proton tracks. Focusing on one-dimensional imaging with a passive collimator, the present study experimentally compared in combination with the first, clinically compatible, dedicated camera device the performances of instances of the two main options: a knife-edge slit (KES) and a multi-parallel slit (MPS) design. These two options were experimentally assessed in this specific context as they were previously demonstrated through analytical and numerical studies to allow similar performances in terms of Bragg peak retrieval precision and spatial resolution in a general context. Both collimators were prototyped according to the conclusions of Monte Carlo optimization studies under constraints of equal weight (40 mm tungsten alloy equivalent thickness) and of the specificities of the camera device under consideration (in particular 4 mm segmentation along beam axis and no time-of-flight discrimination, both of which less favorable to the MPS performance than to the KES one). Acquisitions of proton pencil beams of 100, 160, and 230 MeV in a PMMA target revealed that, in order to reach a given level of statistical precision on Bragg peak depth retrieval, the KES collimator requires only half the dose the present MPS collimator needs, making the KES collimator a preferred option for a compact camera device aimed at imaging only the Bragg peak position. On the other hand, the present MPS collimator proves more effective at retrieving the entrance of the beam in the target in the context of an extended camera device aimed at imaging the whole proton track within the patient.

  14. Comparison of calculated and experimental values of the yields of xenon isotopes in reactions with high-energy protons

    International Nuclear Information System (INIS)

    Shukolyukov, A.Yu.; Katargin, N.V.; Baishev, I.S.

    1989-01-01

    Calculations of the cumulative yields of isotopes of Xe have been carried out on the basis of the semi-empirical formula of Silverberg and Tsao for Ba- and Dy-targets and bombarding proton energies in the range 100-1050 MeV. Results are compared with experimental data for the yields of Xe isotopes, and domains of applicability of the semi-empirical formula are determined

  15. Neutron induced electron radiography; Radiografia com eletrons induzida por neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Marcos Leandro Garcia

    2008-07-01

    In the present paper a new radiography technique, the 'Neutron Induced Electron Radiography' - NIER, to inspect low thickness samples on the order of micra, has been developed. This technique makes use of low energy electrons as penetrating radiation generated from metallic gadolinium screens when irradiated by thermal neutrons. The conditions to obtain the best image for the conventional X-ray film Kodak-AA were determined by using a digital system to quantify the darkening level of the film. The irradiations have been performed at a radiography equipment installed at the beam-hole no. 8 of the 5 MW IEA-R1 nuclear research reactor of IPEN-CNEN/SP. The irradiation time to obtain the best radiography was 100 seconds and for such condition the technique was able to discern 1 {mu}m in 24 {mu}m of aluminum at a resolution of 32 {mu}m. By visual comparison the images obtained by the NIER shown a higher quality when compared with the ones from other usual techniques the make use of electrons a penetrating radiation and films for image registration. Furthermore the use of the digital system has provided a smaller time for data acquisition and data analysis as well as an improvement in the image visualization. (author)

  16. Optimization of digital radiography techniques for specific application

    International Nuclear Information System (INIS)

    Harara, W.

    2010-12-01

    A low cost digital radiography system (DRS) for testing weld joints and castings in laboratory was assembled. The DRS is composed from X-ray source, scintillator, first surface mirror with Aluminum coating, charged coupled device (CCD) camera and lens. The DRS was used to test flawed carbon steel welded plates with thicknesses up to 12 mm. The comparison between the digital radiographs of the plates weldments and the radiographs of the same plates weldments using medium speed film type had shown that, the detection capability of the weld flaws are nearly identical for the two radiography techniques, while the sensitivity achieved in digital radiography of the plates weldments was one IQI wire less than the sensitivity achieved by conventional radiography of the same plates weldments according to EN 462-1. Further, the DRS was also successfully used to test (100 x 100 x 100) mm Aluminum casting with artificial flaws of varied dimensions and orientations. The resulted digital radiographs of the casting show that, all the flaws had been detected and their dimensions can be measured accurately, this confirm that, The proposed DRS can be used to detect and measure the flaws in the Aluminum and others light metals castings accurately. (author)

  17. Radiation protection in technical radiography

    International Nuclear Information System (INIS)

    Thiele, H.

    1980-01-01

    In on-site inspections, e.g. double-plate radiography of circumferential pipe welds Ir-192 is most frequently used. Methods, controlled area, possible personnel doses, and radiation protection measures for the inspection and construction personnel are briefly discussed. (HP) [de

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone ...

  19. Endobronchial Tuberculosis and Chest Radiography

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Sasani

    2016-03-01

    Full Text Available Endobronchial tuberculosis and chest radiography I read, with interest, the article entitled “Clinical and Para-clinical Presentations of Endobronchial Tuberculosis” by Ahmadi Hoseini H. S. et al. (1 published in this journal. I would like to focus on some details about the chest X-ray of patients as elaborated by the authors in the results section. Accordingly, the findings of chest radiography in the available patients were as follows: pulmonary consolidation (75%, reduced pulmonary volume (20%, and hilar adenopathy (10%. This is an incomplete statement because the authors did not explain whether there was any normal chest radiography in the study population. In addition, it is not clear whether the X-ray examinations of the patients were normal, how many abnormal plain films yielded the presented data. On the other hand, the fact that the studied patients had no normal chest radiography is  controversial since in the literature, 10-20% of the patients with endobronchial tuberculosis are reported to have normal chest X-ray (2, 3. In fact, this is one of the problems in the diagnosis of the disease, as well as a potential cause of delayed diagnosis and treatment of the patients. Therefore, the absence of normal chest radiographs is in contrast to the available literature, and if not an error, it could be a subject of further investigation.

  20. Industrial Radiography: Principle and Practical

    International Nuclear Information System (INIS)

    Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

    2008-01-01

    The successful and effectiveness of radiography method as a tool to increase quality level and safety of the engineering system and processing plants depend with the level of radiographer knowledge as service provider and also as supervisor. This book was published as effort several local experts to give their knowledge, theory and practical related to radiography technique to the involved public directly or indirectly. This book started with basic physic knowledge that becomes a root to radiography technology. Then, followed by discussion on tools and device that used in radiography work including x-ray machine, gamma projector, film, dark room, and others. Each aspect of radiograph quality also mentioned here to guide the reader on how to produce good radiograph that filled the specification wanted. The good radiograph does not mean anything if it failed to be interpreted correctly. Because of that, this book also explain how to choose good radiograph that qualified to be interpreted and after that how interpretation and evaluation process of object quality inspected was implemented based on image digestion that showed in radiograph. Several code and standard that usually applied in this country also will be referred as well for this work.

  1. Safety procedures for radiography works

    International Nuclear Information System (INIS)

    Abd Nasir Ibrahim; Azali Muhammad; Ab Razak Hamzah; Abd Aziz Mohamed; Mohammad Pauzi Ismail

    2004-01-01

    The following subjects are discussed - Work preparation: before exposure, during exposure, after work completion. Radiographic work at the open site: types of open sites, establishment of radiographic boundary, storage of radiographic equipment at sites. Safety procedures for radiography works; radiographic works in exposure room

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... ray (Radiography) - Bone Sponsored by Please note RadiologyInfo.org is not a medical facility. Please contact your ... links: For the convenience of our users, RadiologyInfo .org provides links to relevant websites. RadiologyInfo.org , ACR ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that those parts of a patient's body not being imaged receive minimal radiation exposure. top of page What are the limitations of Bone X-ray (Radiography)? ...

  4. Neutron radiography of osteopetrotic rat

    International Nuclear Information System (INIS)

    Graf, B.; Renard, G.; Le Gall, J.; Laporte, A.

    1983-01-01

    The osteopetrotic disease is characterized by bone and cartilage tissue coexistence in the medullary space of long bones. The authors have studied ''congenital osteopetrosis'' of ''op'' rats. Comparing radiography, neutrography and histology, the evolution of the ''osteopetrotic disease'' and the healing of the ill rats by a single injection of bone marrow from normal animals is shown. (Auth.)

  5. Abdomen X-Ray (Radiography)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Abdomen Abdominal x-ray uses a very small ... of an abdominal x-ray? What is abdominal x-ray? An x-ray (radiograph) is a noninvasive medical ...

  6. Practical radiation protection for radiography

    International Nuclear Information System (INIS)

    Hubbard, S.K.; Proudfoot, E.A.

    1978-01-01

    Nondestructive Testing Applications and Radiological Engineering at the Hanford Engineering Development Laboratory have developed radiation protection procedures, radiation work procedures, and safe practice procedures to assure safe operation for all radiographic work. The following topics are discussed: training in radiation safety; radiation exposure due to operations at Hanford; safeguards employed in laboratory radiography; field radiographic operations; and problems

  7. Flash-x-radiography for fuel motion studies

    International Nuclear Information System (INIS)

    Choate, L.M.; Halbleib, J.A. Sr.; Posey, L.D.

    1976-01-01

    The paper is primarily intended to be a status report on recent activities in the Flash X-ray Radiography/Cinematography area. Studies in the area of source definition as well as associated experimental limitations are discussed. The implications of machine current upon precision uncertainty in measurements of changes in areal density are presented. The radiographic techniques presently being evaluated are discussed. Performance estimates representative of this type of diagnostic tool are presented. Comparison with other results is made

  8. Application of nomograms to calculate radiography parameters

    International Nuclear Information System (INIS)

    Voronin, S.A.; Orlov, K.P.; Petukhov, V.I.; Khomchenkov, Yu.F.; Meshalkin, I.A.; Grachev, A.V.; Akopov, V.'S.; Majorov, A.N.

    1979-01-01

    The method of calculation of radiography parameters with the help of nomograms usable for practical application under laboratory and industrial conditions, is proposed. Nomograms are developed for determining the following parameters: relative sensitivity, general non-definition of image, permissible difference of blackening density between the centre and edge of the picture (ΔD), picture contrast, focus distance, item thickness, radiation-physical parameter, dose build up factor, groove dimension and error. An experimental test has been carried out for evaluating the results, obtained with nomograms. Steel items from 25 to 79 mm thick have been subjected to testing 191 Ir has been used as a source. Comparison of calculation and experimental results has shown the discrepancy in sensitivity values, caused by ΔDsub(min) apriori index and the error, inherent in graphical plotting on a nomogram

  9. Proton therapy

    International Nuclear Information System (INIS)

    Smith, Alfred R

    2006-01-01

    Proton therapy has become a subject of considerable interest in the radiation oncology community and it is expected that there will be a substantial growth in proton treatment facilities during the next decade. I was asked to write a historical review of proton therapy based on my personal experiences, which have all occurred in the United States, so therefore I have a somewhat parochial point of view. Space requirements did not permit me to mention all of the existing proton therapy facilities or the names of all of those who have contributed to proton therapy. (review)

  10. Clinical Evaluation of a Dual-Side Readout Technique Computed Radiography System in Chest Radiography of Premature Neonates

    International Nuclear Information System (INIS)

    Carlander, A.; Hansson, J.; Soederberg, J.; Steneryd, K.; Baath, M.

    2008-01-01

    Background: Recently, the dual-side readout technique has been introduced in computed radiography, leading to an increase in detective quantum efficiency (DQE) compared with the single-side readout technique. Purpose: To evaluate if the increase in DQE with the dual-side readout technique results in a higher clinical image quality in chest radiography of premature neonates at no increase in radiation dose. Material and Methods: Twenty-four chest radiographs of premature neonates were collected from both a single-side readout technique system and a double-side readout technique system. The images were processed in the same image-processing station in order for the comparison to be only dependent on the difference in readout technique. Five radiologists rated the fulfillment of four image quality criteria, which were based on important anatomical landmarks. The given ratings were analyzed using visual grading characteristics (VGC) analysis. Results: The VGC analysis showed that the reproduction of the carina with the main bronchi and the thoracic vertebrae behind the heart was better with the dual-side readout technique, whereas no significant difference for the reproduction of the central vessels or the peripheral vessels could be observed. Conclusions: The results indicate that the higher DQE of the dual-side readout technique leads to higher clinical image quality in chest radiography of premature neonates at no increase in radiation dose. Keywords: Digital radiography; lung; observer performance; pediatrics; thorax

  11. Rates of proton transfer to Fe-S-based clusters: comparison of clusters containing {MFe(mu(2)-S)(2)}n+ and {MFe(3)(mu(3)-S)(4)}n+ (M = Fe, Mo, or W) cores.

    Science.gov (United States)

    Bates, Katie; Garrett, Brendan; Henderson, Richard A

    2007-12-24

    The rates of proton transfer from [pyrH]+ (pyr = pyrrolidine) to the binuclear complexes [Fe2S2Cl4]2- and [S2MS2FeCl2]2- (M = Mo or W) are reported. The reactions were studied using stopped-flow spectrophotometry, and the rate constants for proton transfer were determined from analysis of the kinetics of the substitution reactions of these clusters with the nucleophiles Br- or PhS- in the presence of [pyrH]+. In general, Br- is a poor nucleophile for these clusters, and proton transfer occurs before Br- binds, allowing direct measure of the rate of proton transfer from [pyrH]+ to the cluster. In contrast, PhS- is a better nucleophile, and a pathway in which PhS- binds preferentially to the cluster prior to proton transfer from [pyrH]+ usually operates. For the reaction of [Fe2S2Cl4]2- with PhS- in the presence of [pyrH]+ both pathways are observed. Comparison of the results presented in this paper with analogous studies reported earlier on cuboidal Fe-S-based clusters allows discussion of the factors which affect the rates of proton transfer in synthetic clusters including the nuclearity of the cluster core, the metal composition, and the nature of the terminal ligands. The possible relevance of these findings to the protonation sites of natural Fe-S-based clusters, including FeMo-cofactor from nitrogenase, are presented.

  12. SU-F-T-189: Dosimetric Comparison of Spot-Scanning Proton Therapy Techniques for Liver Tumors Close to the Skin Surface

    International Nuclear Information System (INIS)

    Takao, S; Matsuzaki, Y; Matsuura, T; Umegaki, K; Fujii, Y; Fujii, T; Katoh, N; Shimizu, S; Shirato, H

    2016-01-01

    Purpose: Spot-scanning technique has been utilized to achieve conformal dose distribution to large and complicated tumors. This technique generally does not require patient-specific devices such as aperture and compensator. The commercially available spot-scanning proton therapy (SSPT) systems, however, cannot deliver proton beams to the region shallower than 4 g/cm2. Therefore some range compensation device is required to treat superficial tumors with SSPT. This study shows dosimetric comparison of the following treatment techniques: (i) with a tabletop bolus, (ii) with a nozzle-mounted applicator, and (iii) without any devices and using intensity-modulated proton therapy (IMPT) technique. Methods: The applicator composed of a combination of a mini-ridge filter and a range shifter has been manufactured by Hitachi, Ltd., and the tabletop bolus was made by .decimal, Inc. Both devices have been clinically implemented in our facility. Three patients with liver tumors close to the skin surface were examined in this study. Each treatment plan was optimized so that the prescription dose of 76 Gy(RBE) or 66 Gy(RBE) would be delivered to 99% of the clinical target volume in 20 fractions. Three beams were used for tabletop bolus plan and IMPT plan, whereas two beams were used in the applicator plan because the gantry angle available was limited due to potential collision to patient and couch. The normal liver, colon, and skin were considered as organs at risk (OARs). Results: The target heterogeneity index (HI = D_5/D_9_5) was 1.03 on average in each planning technique. The mean dose to the normal liver was considerably less than 20 Gy(RBE) in all cases. The dose to the skin could be reduced by 20 Gy(RBE) on average in the IMPT plan compared to the applicator plan. Conclusion: It has been confirmed that all treatment techniques met the dosimetric criteria for the OARs and could be implemented clinically.

  13. Monte Carlo modelling and comparison with experiment of the nuclide production in thick stony targets isotropically irradiated with 600 MeV protons

    International Nuclear Information System (INIS)

    Aylmer, D.; Herzog, G.F.; Kruse, T.H.; Cloth, P.; Filges, D.; Moniot, R.K.; Signer, P.; Wieler, R.; Tuniz, C.

    1987-05-01

    Depth profiles for the production of stable and radioactive nuclides have been measured for a large variety of target elements in three thick spherical stony targets with radii of 5, 15 and 26 cm isotropically irradiated with 600 MeV protons at the CERN synchrocyclotron. These irradiation experiments (CERN SC96) were intended to simulate the irradiation of meteoroids by galactic cosmic ray protons. In order to combine this experimental approach with a theoretical one the intra- and internuclear cascades were calculated using Monte Carlo techniques via the high energy transport code HET/KFA 1. Together with transport calculations for low energy neutrons by the MORSE-CG code the depth dependent spectra of primary and secondary protons and of secondary neutrons were derived. On the basis of these spectra and a set of evaluated experimental excitation functions for p-induced reactions and of theoretical ones for n-induced reactions, calculated by the code ALICE LIVERMORE 82, theoretical depth profiles for the production of stable and radioactive nuclides in the three thick targets were calculated. This report is a comprehensive survey on all those target/product combination for which both experimental and theoretical data are available. It provides the basis for a detailed discussion of the various production modes of residual nuclides and on the depth and size dependence of their production rates in thick stony targets, serving as a simulation of the galactic cosmic ray irradiation of meteoroids in space. On the other hand the comparison of the experimental and theoretical depth profiles validates the high energy transport calculations, making them a promissing tool for further model calculations of the interactions of cosmic rays with matter. (orig.)

  14. SU-F-T-189: Dosimetric Comparison of Spot-Scanning Proton Therapy Techniques for Liver Tumors Close to the Skin Surface

    Energy Technology Data Exchange (ETDEWEB)

    Takao, S; Matsuzaki, Y [Proton Beam Therapy Center, Hokkaido University Hospital, Sapporo, Hokkaido (Japan); Matsuura, T; Umegaki, K [Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido (Japan); Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido (Japan); Fujii, Y; Fujii, T [Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido (Japan); Katoh, N [Department of Radiation Oncology, Hokkaido University Hospital, Sapporo, Hokkaido (Japan); Shimizu, S; Shirato, H [Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido (Japan); Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido (Japan)

    2016-06-15

    Purpose: Spot-scanning technique has been utilized to achieve conformal dose distribution to large and complicated tumors. This technique generally does not require patient-specific devices such as aperture and compensator. The commercially available spot-scanning proton therapy (SSPT) systems, however, cannot deliver proton beams to the region shallower than 4 g/cm2. Therefore some range compensation device is required to treat superficial tumors with SSPT. This study shows dosimetric comparison of the following treatment techniques: (i) with a tabletop bolus, (ii) with a nozzle-mounted applicator, and (iii) without any devices and using intensity-modulated proton therapy (IMPT) technique. Methods: The applicator composed of a combination of a mini-ridge filter and a range shifter has been manufactured by Hitachi, Ltd., and the tabletop bolus was made by .decimal, Inc. Both devices have been clinically implemented in our facility. Three patients with liver tumors close to the skin surface were examined in this study. Each treatment plan was optimized so that the prescription dose of 76 Gy(RBE) or 66 Gy(RBE) would be delivered to 99% of the clinical target volume in 20 fractions. Three beams were used for tabletop bolus plan and IMPT plan, whereas two beams were used in the applicator plan because the gantry angle available was limited due to potential collision to patient and couch. The normal liver, colon, and skin were considered as organs at risk (OARs). Results: The target heterogeneity index (HI = D{sub 5}/D{sub 95}) was 1.03 on average in each planning technique. The mean dose to the normal liver was considerably less than 20 Gy(RBE) in all cases. The dose to the skin could be reduced by 20 Gy(RBE) on average in the IMPT plan compared to the applicator plan. Conclusion: It has been confirmed that all treatment techniques met the dosimetric criteria for the OARs and could be implemented clinically.

  15. A direct comparison of the biological effects of protons and α-particles having the same LET

    International Nuclear Information System (INIS)

    Mill, A.J.; Hall, S.C.; Allen, L.A.; Goodhead, D.T.

    1991-01-01

    The authors suggest that the findings of Belli et al. (1989) are not universal. A higher effectiveness for protons compared with α-particles appears to be either small or absent in the systems reported in this paper (C 3 H 10T1/2 mouse cells and HeLa human cells). However, the possible existence of such an effect places cons-traints on understanding of the mechanisms of radiation action. On a practical level these small differences in effectiveness are not significant for radiological protection issues and LET remains a suitable parameter for the determination of the risk from high-LET radiations. (UK)

  16. submitter Proton therapy treatment monitoring with the DoPET system: activity range, positron emitters evaluation and comparison with Monte Carlo predictions

    CERN Document Server

    Muraro, S; Belcari, N; Bisogni, M G; Camarlinghi, N; Cristoforetti, L; Guerra, A Del; Ferrari, A; Fracchiolla, F; Morrocchi, M; Righetto, R; Sala, P; Schwarz, M; Sportelli, G; Topi, A; Rosso, V

    2017-01-01

    Ion beam irradiations can deliver conformal dose distributions minimizing damage to healthy tissues thanks to their characteristic dose profiles. Nevertheless, the location of the Bragg peak can be affected by different sources of range uncertainties: a critical issue is the treatment verification. During the treatment delivery, nuclear interactions between the ions and the irradiated tissues generate β+ emitters: the detection of this activity signal can be used to perform the treatment monitoring if an expected activity distribution is available for comparison. Monte Carlo (MC) codes are widely used in the particle therapy community to evaluate the radiation transport and interaction with matter. In this work, FLUKA MC code was used to simulate the experimental conditions of irradiations performed at the Proton Therapy Center in Trento (IT). Several mono-energetic pencil beams were delivered on phantoms mimicking human tissues. The activity signals were acquired with a PET system (DoPET) based on two plana...

  17. Videofluoroscopy of the pharynx and esophagus in patients with globus pharyngis. Comparison with static radiography; Die radiologische Abklaerung des Globus pharyngis. Vergleich der diagnostischen Wertigkeit von konventionellem Roentgen mit der Videokinematographie

    Energy Technology Data Exchange (ETDEWEB)

    Schober, E. [Abt. Roentgen fuer Konservative Faecher, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria); Schima, W. [Abt. Roentgen fuer Konservative Faecher, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria); Pokieser, P. [Abt. Roentgen fuer Chirurgische Faecher, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria)

    1995-10-01

    The symptom is associated with a multitude of pharyngoesophageal abnormalities. Our study compares the diagnostic yield of videofluoroscopy to that of static radiography in patients suffering from globus pharnygis. A total of 150 consecutive patients complaining of a lump in the throat, but without evidence of dysphagia, were studied in a standardized fashion with both methods. Videofluoroscopy combined with static radiography revealed morphological or functional abnormalities in 75% of our patients. The combination of the two methods yielded significantly more abnormalities in the pharynx and esophagus than videofluoroscopy or static radiography alone. Esophageal motor disorders, pharyngoesophageal sphincter dysfunction and pharyngeal residue of contrast material proved to be the most common abnormalities. In conclusion, videofluoroscopy combined with static radiography is mandatory in the radiological assessment of patients suffering from the globus sensation. (orig.) [Deutsch] Unsere Studie vergleicht die diagnostische Wertigkeit des konventionellen Roentgens mit jener der Videokineamtographie von Pharynx und Oesophagus bei der Abklaerung des Globusgefuehls. Wir haben 150 konsekutive Patienten mit Globusgefuehl, jedoch ohne Dysphagie mit beiden Methoden nach einem standardisierten Protokoll untersucht. Mittels der Kombination von konventionellem Roentgen mit der Videokinematographie fanden sich bei 75% der Patienten pathologische Veraenderungen. Durch die Kombination beider Methoden konnten signifikant mehr morphologische und funktionelle Stoerungen des Pharynx sowie Oesophagus aufgezeigt werden, als mit der alleinigen konventionellen Technik oder der alleinigen Videokinematographie. Die haeufigsten pathologischen Veraenderungen in unserem Kollektiv waren Oesophagusmotilitaetsstoerungen, eine Dyskinesie des pharyngooesophagealen Sphinkters sowie eine abnorme pharyngeale Kontrastmittelretention. Unsere Ergebnisse belegen eindeutig, dass die radiologische

  18. Technical Note: A treatment plan comparison between dynamic collimation and a fixed aperture during spot scanning proton therapy for brain treatment

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Blake, E-mail: bsmith34@wisc.edu; Gelover, Edgar; Moignier, Alexandra; Wang, Dongxu; Flynn, Ryan T.; Hyer, Daniel E. [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Lin, Liyong; Kirk, Maura; Solberg, Tim [Department of Radiation Oncology, University of Pennsylvania, TRC 2 West, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania 19104 (United States)

    2016-08-15

    Purpose: To quantitatively assess the advantages of energy-layer specific dynamic collimation system (DCS) versus a per-field fixed aperture for spot scanning proton therapy (SSPT). Methods: Five brain cancer patients previously planned and treated with SSPT were replanned using an in-house treatment planning system capable of modeling collimated and uncollimated proton beamlets. The uncollimated plans, which served as a baseline for comparison, reproduced the target coverage and organ-at-risk sparing of the clinically delivered plans. The collimator opening for the fixed aperture-based plans was determined from the combined cross sections of the target in the beam’s eye view over all energy layers which included an additional margin equivalent to the maximum beamlet displacement for the respective energy of that energy layer. The DCS-based plans were created by selecting appropriate collimator positions for each row of beam spots during a Raster-style scanning pattern which were optimized to maximize the dose contributions to the target and limited the dose delivered to adjacent normal tissue. Results: The reduction of mean dose to normal tissue adjacent to the target, as defined by a 10 mm ring surrounding the target, averaged 13.65% (range: 11.8%–16.9%) and 5.18% (2.9%–7.1%) for the DCS and fixed aperture plans, respectively. The conformity index, as defined by the ratio of the volume of the 50% isodose line to the target volume, yielded an average improvement of 21.35% (19.4%–22.6%) and 8.38% (4.7%–12.0%) for the DCS and fixed aperture plans, respectively. Conclusions: The ability of the DCS to provide collimation to each energy layer yielded better conformity in comparison to fixed aperture plans.

  19. Technical Note: A treatment plan comparison between dynamic collimation and a fixed aperture during spot scanning proton therapy for brain treatment

    International Nuclear Information System (INIS)

    Smith, Blake; Gelover, Edgar; Moignier, Alexandra; Wang, Dongxu; Flynn, Ryan T.; Hyer, Daniel E.; Lin, Liyong; Kirk, Maura; Solberg, Tim

    2016-01-01

    Purpose: To quantitatively assess the advantages of energy-layer specific dynamic collimation system (DCS) versus a per-field fixed aperture for spot scanning proton therapy (SSPT). Methods: Five brain cancer patients previously planned and treated with SSPT were replanned using an in-house treatment planning system capable of modeling collimated and uncollimated proton beamlets. The uncollimated plans, which served as a baseline for comparison, reproduced the target coverage and organ-at-risk sparing of the clinically delivered plans. The collimator opening for the fixed aperture-based plans was determined from the combined cross sections of the target in the beam’s eye view over all energy layers which included an additional margin equivalent to the maximum beamlet displacement for the respective energy of that energy layer. The DCS-based plans were created by selecting appropriate collimator positions for each row of beam spots during a Raster-style scanning pattern which were optimized to maximize the dose contributions to the target and limited the dose delivered to adjacent normal tissue. Results: The reduction of mean dose to normal tissue adjacent to the target, as defined by a 10 mm ring surrounding the target, averaged 13.65% (range: 11.8%–16.9%) and 5.18% (2.9%–7.1%) for the DCS and fixed aperture plans, respectively. The conformity index, as defined by the ratio of the volume of the 50% isodose line to the target volume, yielded an average improvement of 21.35% (19.4%–22.6%) and 8.38% (4.7%–12.0%) for the DCS and fixed aperture plans, respectively. Conclusions: The ability of the DCS to provide collimation to each energy layer yielded better conformity in comparison to fixed aperture plans.

  20. Technical Note: A treatment plan comparison between dynamic collimation and a fixed aperture during spot scanning proton therapy for brain treatment

    Science.gov (United States)

    Smith, Blake; Gelover, Edgar; Moignier, Alexandra; Wang, Dongxu; Flynn, Ryan T.; Lin, Liyong; Kirk, Maura; Solberg, Tim; Hyer, Daniel E.

    2016-01-01

    Purpose: To quantitatively assess the advantages of energy-layer specific dynamic collimation system (DCS) versus a per-field fixed aperture for spot scanning proton therapy (SSPT). Methods: Five brain cancer patients previously planned and treated with SSPT were replanned using an in-house treatment planning system capable of modeling collimated and uncollimated proton beamlets. The uncollimated plans, which served as a baseline for comparison, reproduced the target coverage and organ-at-risk sparing of the clinically delivered plans. The collimator opening for the fixed aperture-based plans was determined from the combined cross sections of the target in the beam’s eye view over all energy layers which included an additional margin equivalent to the maximum beamlet displacement for the respective energy of that energy layer. The DCS-based plans were created by selecting appropriate collimator positions for each row of beam spots during a Raster-style scanning pattern which were optimized to maximize the dose contributions to the target and limited the dose delivered to adjacent normal tissue. Results: The reduction of mean dose to normal tissue adjacent to the target, as defined by a 10 mm ring surrounding the target, averaged 13.65% (range: 11.8%–16.9%) and 5.18% (2.9%–7.1%) for the DCS and fixed aperture plans, respectively. The conformity index, as defined by the ratio of the volume of the 50% isodose line to the target volume, yielded an average improvement of 21.35% (19.4%–22.6%) and 8.38% (4.7%–12.0%) for the DCS and fixed aperture plans, respectively. Conclusions: The ability of the DCS to provide collimation to each energy layer yielded better conformity in comparison to fixed aperture plans. PMID:27487886

  1. System for uncollimated digital radiography

    Science.gov (United States)

    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. Industrial radiography X and Gamma

    International Nuclear Information System (INIS)

    Torres M, Nelson; Torres B, Miguel; Montanez, Juan.

    1986-04-01

    This publication gives a practical orientation on industrial radiography. The first chapters deal with basic facts that are useful for professional work in this field. It comprises topics such as generation of X-rays, equipment being used, radiographic films, sensibility, and the penetrameters used. This publication also describes the most used radiographic techniques and the processing of the radiographic film. It contains practical recommendations on how to obtain a good radiographic inspection. It states the reasons for defects in the radiographies. Two annexes are attached which include tables for the selection of penetrameters according to the ASME and DIN codes as well as the time needed for development and fixing according to the temperature

  3. Industrial radiography with phosphor screens

    International Nuclear Information System (INIS)

    Broadhead, P.

    1981-01-01

    An experimental system that comprises a film of low silver content and a pair of high resolution phosphor intensifying screens and a commercial industrial X-ray film of similar speed are compared for image quality. It is concluded that the use of phosphor screens offers an increase in image quality when the information is limited by the graininess or quantum mottle of a radiograph which is frequently the case in practical radiography. (author)

  4. Radiological security for industrial radiography