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Sample records for computed radiography analysis

  1. Comparison of different computed radiography systems: Physical characterization and contrast detail analysis

    Rivetti, Stefano; Lanconelli, Nico; Bertolini, Marco; Nitrosi, Andrea; Burani, Aldo; Acchiappati, Domenico [Servizio Fisica Sanitaria, ' ' Azienda USL di Modena' ' , 41100 Modena (Italy); Department of Physics, Alma Mater Studiorum, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna (Italy); Arcispedale Santa Maria Nuova, 42123 Reggio Emilia (Italy); ' ' Azienda USL di Modena' ' , Ospedale di Sassuolo, 41049 Sassuolo (Italy); Servizio Fisica Sanitaria, ' ' Azienda USL di Modena' ' , 41100 Modena (Italy)

    2010-02-15

    Purpose: In this study, five different units based on three different technologies--traditional computed radiography (CR) units with granular phosphor and single-side reading, granular phosphor and dual-side reading, and columnar phosphor and line-scanning reading--are compared in terms of physical characterization and contrast detail analysis. Methods: The physical characterization of the five systems was obtained with the standard beam condition RQA5. Three of the units have been developed by FUJIFILM (FCR ST-VI, FCR ST-BD, and FCR Velocity U), one by Kodak (Direct View CR 975), and one by Agfa (DX-S). The quantitative comparison is based on the calculation of the modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE). Noise investigation was also achieved by using a relative standard deviation analysis. Psychophysical characterization is assessed by performing a contrast detail analysis with an automatic reading of CDRAD images. Results: The most advanced units based on columnar phosphors provide MTF values in line or better than those from conventional CR systems. The greater thickness of the columnar phosphor improves the efficiency, allowing for enhanced noise properties. In fact, NPS values for standard CR systems are remarkably higher for all the investigated exposures and especially for frequencies up to 3.5 lp/mm. As a consequence, DQE values for the three units based on columnar phosphors and line-scanning reading, or granular phosphor and dual-side reading, are neatly better than those from conventional CR systems. Actually, DQE values of about 40% are easily achievable for all the investigated exposures. Conclusions: This study suggests that systems based on the dual-side reading or line-scanning reading with columnar phosphors provide a remarkable improvement when compared to conventional CR units and yield results in line with those obtained from most digital detectors for radiography.

  2. Standard guide for computed radiography

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This guide provides general tutorial information regarding the fundamental and physical principles of computed radiography (CR), definitions and terminology required to understand the basic CR process. An introduction to some of the limitations that are typically encountered during the establishment of techniques and basic image processing methods are also provided. This guide does not provide specific techniques or acceptance criteria for specific end-user inspection applications. Information presented within this guide may be useful in conjunction with those standards of 1.2. 1.2 CR techniques for general inspection applications may be found in Practice E2033. Technical qualification attributes for CR systems may be found in Practice E2445. Criteria for classification of CR system technical performance levels may be found in Practice E2446. Reference Images Standards E2422, E2660, and E2669 contain digital reference acceptance illustrations. 1.3 The values stated in SI units are to be regarded as the st...

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

    Mustonen, A.O.T. [Helsinki Univ. Central Hospital (Finland). Dept. of Radiology; Koskinen, S.K. [Research Inst. of Military Medicine, Helsinki (Finland); Kiuru, M.J. [ORTON Orthopaedic Hospital, Helsinki (Finland)

    2005-12-01

    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.

  4. Clinical evaluation of irreversible image compression: analysis of chest imaging with computed radiography.

    Ishigaki, T; Sakuma, S; Ikeda, M; Itoh, Y; Suzuki, M; Iwai, S

    1990-06-01

    To implement a picture archiving and communication system, clinical evaluation of irreversible image compression with a newly developed modified two-dimensional discrete cosine transform (DCT) and bit-allocation technique was performed for chest images with computed radiography (CR). CR images were observed on a cathode-ray-tube monitor in a 1,024 X 1,536 matrix. One original and five reconstructed versions of the same images with compression ratios of 3:1, 6:1, 13:1, 19:1, and 31:1 were ranked according to quality. Test images with higher spatial frequency were ranked better than those with lower spatial frequency and the acceptable upper limit of the compression ratio was 19:1. In studies of receiver operating characteristics for scoring the presence or absence of nodules and linear shadows, the images with a compression ratio of 25:1 showed a statistical difference as compared with the other images with a compression ratio of 20:1 or less. Both studies show that plain CR chest images with a compression ratio of 10:1 are acceptable and, with use of an improved DCT technique, the upper limit of the compression ratio is 20:1.

  5. Practical application of suspension criteria scenarios in general radiography, computed radiography,digital radiography and fluoroscopy.

    O'Connor, U; Gallagher, A; O'Reilly, G; Dowling, A; Malone, J F

    2013-02-01

    Radiological equipment must be assessed against criteria for acceptability to ensure that it meets the minimum standards for patient safety. This assessment is typically led by a medical physicist with input from radiology staff and the equipment supplier. Equipment that does not meet the criteria requires action and may be suspended from clinical use. European Commission report RP 91 will be revised and replaced as RP 162. It has been drawn up to aid medical physicists with the assessment process and provide guidance on suspension levels. This paper details several cases where the criteria in the proposed RP 162 were applied in general radiography, computed radiography, digital radiography and fluoroscopy. The factors considered by the medical physicist and the outcome of each case are presented. The proposed RP 162 report improves on its predecessor and provides a robust set of criteria for ensuring that patient safety within the EU medical exposures framework is optimised.

  6. New computed radiography processing condition for whole-spine radiography.

    Sasagawa, Takeshi; Kunogi, Junichi; Masuyama, Shigeru; Ogihara, Satoshi; Takeuchi, Yosuke; Takeshita, Yujiro; Kamiya, Naokazu; Murakami, Hideki; Tsuchiya, Hiroyuki

    2011-12-06

    Computed radiography (CR) has many advantages compared with conventional radiographs, especially in image processing. Although CR is being used in chest radiography and mammography, it has not been applied to spine imaging. The purposes of this study were to formulate a set of new CR processing parameters and to test whether the resultant whole-spine radiographs visualized the spine more clearly than conventional images. This study included 29 patients who underwent whole-spine radiographs. We used 3 image processing methods to improve the clarity of whole-spine radiographs: gradation processing, dynamic range control processing, and multi-objective frequency processing. Radiograph definition was evaluated using vertebrae sampled from each region of the whole spine, specifically C4, C7, T8, T12, and L3; evaluation of the lateral view also included the sacral spine and femoral head. Image definition was assessed using a 3-point grading system. The conventional and processed CR images (both frontal and lateral views) were evaluated by 5 spine surgeons. In all spinal regions on both frontal and lateral views, the processed images showed statistically significantly better clarity than the corresponding conventional images, especially at T12, L3, the sacral spine, and the femoral head on the lateral view. Our set of new CR processing parameters can improve the clarity of whole-spine radiographs compared with conventional images. The greatest advantage of image processing was that it enabled clear depiction of the thoracolumbar junction, lumbar vertebrae, sacrum, and femoral head in the lateral view.

  7. Computed radiography simulation using the Monte Carlo code MCNPX

    Correa, S.C.A. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Centro Universitario Estadual da Zona Oeste (CCMAT)/UEZO, Av. Manuel Caldeira de Alvarenga, 1203, Campo Grande, 23070-200, Rio de Janeiro, RJ (Brazil); Souza, E.M. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Silva, A.X., E-mail: ademir@con.ufrj.b [PEN/COPPE-DNC/Poli CT, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Cassiano, D.H. [Instituto de Radioprotecao e Dosimetria/CNEN Av. Salvador Allende, s/n, Recreio, 22780-160, Rio de Janeiro, RJ (Brazil); Lopes, R.T. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil)

    2010-09-15

    Simulating X-ray images has been of great interest in recent years as it makes possible an analysis of how X-ray images are affected owing to relevant operating parameters. In this paper, a procedure for simulating computed radiographic images using the Monte Carlo code MCNPX is proposed. The sensitivity curve of the BaFBr image plate detector as well as the characteristic noise of a 16-bit computed radiography system were considered during the methodology's development. The results obtained confirm that the proposed procedure for simulating computed radiographic images is satisfactory, as it allows obtaining results comparable with experimental data.

  8. Portable Digital Radiography and Computed Tomography Manual

    2007-11-01

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

  9. Simulation of computed radiography with imaging plate detectors

    Tisseur, D.; Costin, M. [CEA LIST, CEA Saclay 91191 Gif sur Yvette Cedex (France); Mathy, F. [CEA-LETI, Campus Minatec, F-38054, Grenoble (France); Schumm, A. [EDF R and D, 1 avenue du général de gaulle 92141 Clamart (France)

    2014-02-18

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

  10. Single-exposure dual-energy computed radiography.

    Stewart, B K; Huang, H K

    1990-01-01

    This paper focuses on analysis and development of a single-exposure dual-energy digital radiographic method using computed radiography (Fuji FCR-101 storage phosphor system). A detector sandwich consisting of storage phosphor imaging plates and an interdetector filter is used. The goal of this process is to provide a simple dual-energy method using typical plane-projection radiographic equipment and techniques. This approach exploits the transparency of the storage phosphor plates, using radiographic information that would be otherwise lost, to provide energy selective information essentially as a by-product of the radiographic examination. In order to effectively make use of the large dynamic range of the storage phosphor imaging plates (10,000:1), a computed radiography image reading mode of fixed analog-to-digital converter gain and variable photomultiplier sensitivity provides image data which can be related to relative incident exposure for export to the decomposition algorithm. Scatter rejection requirements necessitated crossed 12:1 grids for a field size of 36 x 36 cm. Optimal technique parameters obtained from computer simulation through minimization of the aluminum and Plexiglas equivalent image uncertainty under conditions of constant absorbed does resulted as: 100 kVp using a 0.15-mm-thick tin (Sn) interdetector filter for the lung field. This yields a surface exposure of 23 mR and a surface absorbed dose of 0.26 mGy for a 23-cm-thick chest. Clinical application in evaluation of the solitary pulmonary nodule is discussed, along with an image set demonstrating this application.

  11. Performance evaluation of a direct computed radiography system by means of physical characterization and contrast detail analysis

    Rivetti, Stefano; Lanconelli, Nico; Bertolini, Marco; Borasi, Giovanni; Acchiappati, Domenico; Burani, Aldo

    2007-03-01

    The aim of this study is to determine the performance of a direct CR reader, named "FCR Velocity U Focused Phosphor (FP)". The system is based on a CsBr columnar structured crystal, and the system's read out is based on the "linescan technology" that employs a wide-view CCD. The system's physical performance was tested by means of a quantitative analysis, with calculation of the modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE). Image quality was assessed by performing a contrast-detail analysis. The results are compared with those obtained with the well known CR system Fuji FCR XG5000, and the new one Kodak DirectView CR 975. For all the measurements the standard radiation quality RQA-5 was used. The relationship between signal amplitude and entrance air kerma is logarithmic for all the systems and the response functions were used to linearize the images before the MTF (edge method) and NPS calculations. The contrast detail analysis has been achieved by using the well known CDRAD phantom and a customized software designed for automatic computation of the contrast-detail curves. The three systems present similar MTFs, whereas the Fuji Velocity U FP system, thanks to its greater efficiency, has a better behavior in terms of NNPS, especially at low frequencies. That allows the system based on columnar phosphor to provide a better DQE. CDRAD analysis basically confirms that the structured phosphor used in the Velocity system improves the visibility of some details. This is especially true for medium and large details.

  12. Analysis of edentulous maxillae using computed tomography and panoramic radiography in the surgical planning of dental implants; Analise da maxila edentula por meio da tomografia computadorizada e radiografia panoramica no planejamento cirurgico de implantes dentarios

    Sahuinco, Humberto Lazaro Choquepuma; Souza, Ricardo Pires de [Complexo Hospitalar Heliopolis (HOSPHEL), Sao Paulo, SP (Brazil). Curso de pos-graduacao em Ciencias da Saude]. E-mail: humbertchs@hotmail.com

    2006-04-15

    Objective: to determine agreement of three observers on analysis of linear measurements of edentulous maxillae using computed tomography and panoramic radiography in the surgical planning of dental implants. Material and Method: the samples of 17 patients were analyzed with computed tomography and panoramic radiography. Linear measurements obtained from both methods were made at the following anatomical points: left tuberosity, left canine pillar, incisive foramen, right canine pillar and right tuberosity. Kendall's W test was applied to assess the level of agreement. Results: measured W-values from the samples of the anatomical points mentioned above, analyzed with panoramic radiography and computed tomography, were: 0.75 and 0.901; 0.916 and 0.956; 0.843 and 0.964; 0.963 and 0.931; 0.95 and 0.89 respectively. Statistical analysis showed that there was no statistically significant difference. Conclusion: agreement occurred in the measurements of variables.That means that if the three observers were to select an implant to be placed in each of the anatomical regions studied, there would be a good chance whey would choose the same type. (author)

  13. Application of computed radiography for power plant tube

    Chnag, Hee Jun; Kim, Sun Je; Yang, Yun Sick; Kim, Jong Duck; Lim, Sung Hee [Dosan Heavey Industries and Constrution Co.,Ltd, Changwon (Korea, Republic of); Park, Young Ha [Shinki Commercial Co.,Ltd, Seoul (Korea, Republic of)

    2005-05-15

    For radiographic examination, it is imperative that the film characteristics be determined so that optimal test conditions, and the result thereof, can be verified by analyzing the film values with regard to different radiation sources, and for standardizing the characteristics such as sensitivity, exposure thickness range (latitude) and maximum and minimum exposure dose, The research presented in this paper was aimed at evaluating the radioactive sensitivity characteristics of the Image Plate, in lieu of film, as used in Computer Radiography for various radiation sources, in order to apply this newly developed technology in other industrial fields, and in particular, the Power Plant industry. Several possibilities and improvements were discovered with the substitution of Computer Radiography for Conventional Film Radiographic Test.

  14. Practical guidelines for radiographers to improve computed radiography image quality

    Pongnapang, N

    2005-01-01

    Computed Radiography (CR) has become a major digital imaging modality in a modern radiological department. CR system changes workflow from the conventional way of using film/screen by employing photostimulable phosphor plate technology. This results in the changing perspectives of technical, artefacts and quality control issues in radiology departments. Guidelines for better image quality in digital medical enterprise include professional guidelines for users and the quality control programme...

  15. Computer-aided diagnosis in chest radiography: Beyond nodules

    Ginneken, Bram van [University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands)], E-mail: bram@isi.uu.nl; Hogeweg, Laurens; Prokop, Mathias [University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands)

    2009-11-15

    Chest radiographs are the most common exam in radiology. They are essential for the management of various diseases associated with high mortality and morbidity and display a wide range of findings, many of them subtle. In this survey we identify a number of areas beyond pulmonary nodules that could benefit from computer-aided detection and diagnosis (CAD) in chest radiography. These include interstitial infiltrates, catheter tip detection, size measurements, detection of pneumothorax and detection and quantification of emphysema. Recent work in these areas is surveyed, but we conclude that the amount of research devoted to these topics is modest. Reasons for the slow pace of CAD development in chest radiography beyond nodules are discussed.

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

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

    2007-09-01

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

  17. [Development of computer assisted learning program using cone beam projection for head radiography].

    Nakazeko, Kazuma; Kajiwara, Hironori; Watanabe, Hiroyuki; Kuwayama, Jun; Karube, Shuhei; Araki, Misao; Hashimoto, Takeyuki; Shinohara, Hiroyuki

    2012-01-01

    We present a computer assisted learning (CAL) program to simulate head radiography. The program provides cone beam projections of a target volume, simulating three-dimensional computed tomography (CT) of a head phantom. The generated image is 512 x 512 x 512 pixels with each pixel 0.6 mm on a side. The imaging geometry, such as X-ray tube orientation and phantom orientation, can be varied. The graphical user interface (GUI) of the CAL program allows the study of the effects of varying the imaging geometry; each simulated projection image is shown quickly in an adjoining window. Simulated images with an assigned geometry were compared with the image obtained using the standard geometry in clinical use. The accuracy of the simulated image was verified through comparison with the image acquired using radiography of the head phantom, subsequently processed with a computed radiography system (CR image). Based on correlation coefficient analysis and visual assessment, it was concluded that the CAL program can satisfactorily simulate the CR image. Therefore, it should be useful for the training of head radiography.

  18. Management of pediatric radiation dose using Agfa computed radiography

    Schaetzing, R. [Agfa Corp., Greenville, SC (United States)

    2004-10-01

    Radiation dose to patients and its management have become important considerations in modern radiographic imaging procedures, but they acquire particular significance in the imaging of children. Because of their longer life expectancy, children exposed to radiation are thought to have a significantly increased risk of radiation-related late sequelae compared to adults first exposed to radiation later in life. Therefore, current clinical thinking dictates that dose in pediatric radiography be minimized, while simultaneously ensuring sufficient diagnostic information in the image, and reducing the need for repeat exposures. Dose management obviously starts with characterization and control of the exposure technique. However, it extends farther through the imaging chain to the acquisition system, and even to the image processing techniques used to optimize acquired images for display. Further, other factors, such as quality control procedures and the ability to handle special pediatric procedures, like scoliosis exams, also come into play. The need for dose management in modern radiography systems has spawned a variety of different solutions, some of which are similar across different manufacturers, and some of which are unique. This paper covers the techniques used in Agfa Computed Radiography (CR) systems to manage dose in a pediatric environment. (orig.)

  19. Advances in computed radiography systems and their physical imaging characteristics.

    Cowen, A R; Davies, A G; Kengyelics, S M

    2007-12-01

    Radiological imaging is progressing towards an all-digital future, across the spectrum of medical imaging techniques. Computed radiography (CR) has provided a ready pathway from screen film to digital radiography and a convenient entry point to PACS. This review briefly revisits the principles of modern CR systems and their physical imaging characteristics. Wide dynamic range and digital image enhancement are well-established benefits of CR, which lend themselves to improved image presentation and reduced rates of repeat exposures. However, in its original form CR offered limited scope for reducing the radiation dose per radiographic exposure, compared with screen film. Recent innovations in CR, including the use of dual-sided image readout and channelled storage phosphor have eased these concerns. For example, introduction of these technologies has improved detective quantum efficiency (DQE) by approximately 50 and 100%, respectively, compared with standard CR. As a result CR currently affords greater scope for reducing patient dose, and provides a more substantive challenge to the new solid-state, flat-panel, digital radiography detectors.

  20. A computer-assisted systematic quality monitoring method for cervical hip fracture radiography

    Mats Geijer

    2016-12-01

    Full Text Available Background A thorough quality analysis of radiologic performance is cumbersome. Instead, the prevalence of missed cervical hip fractures might be used as a quality indicator. Purpose To validate a computer-based quality study of cervical hip fracture radiography. Material and Methods True and false negative and positive hip trauma radiography during 6 years was assessed manually. Patients with two or more radiologic hip examinations before surgery were selected by computer analysis of the databases. The first of two preoperative examinations might constitute a missed fracture. These cases were reviewed. Results Out of 1621 cervical hip fractures, manual perusal found 51 (3.1% false negative radiographic diagnoses. Among approximately 14,000 radiographic hip examinations, there were 27 (0.2% false positive diagnoses. Fifty-seven percent of false negative reports were occult fractures, the other diagnostic mistakes. There were no significant differences over the years. Diagnostic sensitivity was 96.9% and specificity 99.8%. Computer-assisted analysis with a time interval of at least 120 days between the first and the second radiographic examination discovered 39 of the 51 false negative reports. Conclusion Cervical hip trauma radiography has high sensitivity and specificity. With computer-assisted analysis, 76% of false negative reports were found.

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

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

    2005-12-01

    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 (chi(2) tests).

  2. Technical and clinical breast cancer screening performance indicators for computed radiography versus direct digital radiography

    Bosmans, Hilde; Lemmens, Kim; Zanca, Federica; Ongeval, Chantal van; Steen, Andre van [University Hospitals Leuven, Department of Radiology, Leuven (Belgium); Hauwere, An de; Thierens, Hubert [Ghent University, QCC, Ghent (Belgium); Herck, Koen van; Bleyen, Luc; Mortier, Griet [Ghent University, Centrum voor Preventie en Vroegtijdige Opsporing van Kanker, Department of Public Health, Ghent (Belgium); Martens, Patrick [Vroegtijdige Opsporing Borstklierkanker West-Vlaanderen vzw, Bruges (Belgium); Putte, Gretel vande; Kellen, Eliane; Limbergen, Erik van [Leuven University Center of Cancer Screening, Leuven (Belgium)

    2013-10-15

    To compare technical and clinical screening performance parameters between computed radiography (CR) and direct digital radiography (DR) systems. The number of women screened with CR was 73,008 and with DR 116,945. Technical and patient dose survey data of 25 CR and 37 DR systems were available. Technical performance was expressed by threshold thickness values at the mean glandular dose (MGD) level of routine practice. Clinical indicators included recall rate (RR), cancer detection rate (CDR), percentage of ductal carcinoma in situ (DCIS), percentage of cancers with T-scores smaller than 1 cm and positive predictive value (PPV). Contrast threshold values for the 0.1-mm gold disk were 1.44 {mu}m (SD 0.13 {mu}m) for CR and 1.20 {mu}m (SD 0.13 {mu}m for DR). MGD was 2.16 mGy (SD 0.36 mGy) and 1.35 mGy (SD 0.32 mGy) for CR and DR respectively. We obtained for CR, respectively DR, the following results: RR in the first round of 5.48 % versus 5.61 %; RR in subsequent rounds of 2.52 % versus 2.65 %; CDR of 0.52 % versus 0.53 %; DCIS of 0.08 % versus 0.11 %; a rate of cancers with T-scores smaller than 1 cm of 0.11 % versus 0.11 %; PPV of 18.45 % versus 18.64 %; none of them was significantly different. Our screening indicators are reassuring for the use of CR and DR, with CR operating at 60 % higher MGD. (orig.)

  3. Computed Tomography and Computed Radiography of late Bronze Age Cremation Urns from Denmark

    Harvig, Lise Lock; Lynnerup, Niels; Amsgaard Ebsen, Jannie

    2012-01-01

    To improve methods used to study prehistoric cremation rituals, cremation urns from the Danish late Bronze Age were examined using Computed Tomography and Computed Radiography (Digital X-ray). During microexcavation, the digital images were used as registration tool. Our results suggest...

  4. Detection of urinary stones at reduced radiation exposure: a phantom study comparing computed radiography and a low-dose digital radiography linear slit scanning system

    Szucs-Farkas, Zsolt; Chakraborty, D. P.; Thoeny, Harriet C.; Loupatatzis, Christos; Vock, Peter; Harald, Bonel

    2010-01-01

    Objective In this experimental study we assessed the diagnostic performance of linear slit scanning radiography (LSSR) compared to conventional computed radiography (CR) in the detection of urinary calculi in an anthropomorphic phantom imitating patients weighing approximately 58 to 88 kg. Conclusion Compared to computed radiography, LSSR is superior in the detection of urinary stones and may be used for pretreatment localization and follow-up at a lower patient exposure. PMID:19457787

  5. Practical guidelines for radiographers to improve computed radiography image quality.

    Pongnapang, N

    2005-10-01

    Computed Radiography (CR) has become a major digital imaging modality in a modern radiological department. CR system changes workflow from the conventional way of using film/screen by employing photostimulable phosphor plate technology. This results in the changing perspectives of technical, artefacts and quality control issues in radiology departments. Guidelines for better image quality in digital medical enterprise include professional guidelines for users and the quality control programme specifically designed to serve the best quality of clinical images. Radiographers who understand technological shift of the CR from conventional method can employ optimization of CR images. Proper anatomic collimation and exposure techniques for each radiographic projection are crucial steps in producing quality digital images. Matching image processing with specific anatomy is also important factor that radiographers should realise. Successful shift from conventional to fully digitised radiology department requires skilful radiographers who utilise the technology and a successful quality control program from teamwork in the department.

  6. Assessment of weld thickness loss in offshore pipelines using computed radiography and computational modeling

    Correa, S.C.A. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Centro Universitario Estadual da Zona Oeste - UEZO, Avenida Manuel Caldeira de Alvarenga, 1203, 23070-200, Rio de Janeiro, RJ (Brazil)], E-mail: scorrea@con.ufrj.br; Souza, E.M. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Departamento de Geologia/IGEO, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Oliveira, D.F. [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Silva, A.X. [PEN/COPPE-DNC/Poli-CT, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Lopes, R.T. [Programa de Engenharia Nuclear, COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Marinho, C.; Camerini, C.S. [CENPES/PDEP/TMEC/PETROBRAS, Ilha do Fundao, Cidade Universitaria, 21949-900, Rio de Janeiro, RJ (Brazil)

    2009-10-15

    In order to guarantee the structural integrity of oil plants it is crucial to monitor the amount of weld thickness loss in offshore pipelines. However, in spite of its relevance, this parameter is very difficult to determine, due to both the large diameter of most pipes and the complexity of the multi-variable system involved. In this study, a computational modeling based on Monte Carlo MCNPX code is combined with computed radiography to estimate the weld thickness loss in large-diameter offshore pipelines. Results show that computational modeling is a powerful tool to estimate intensity variations in radiographic images generated by weld thickness variations, and it can be combined with computed radiography to assess weld thickness loss in offshore and subsea pipelines.

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

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

    2016-07-01

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

  8. Application of digital radiography in the analysis of cultural heritage

    Oiveira, Davi F.; Calza, Cristiane; Rocha, Henrique S.; Nascimento, Joseilson R.; Lopes, Ricardo T., E-mail: davi@lin.ufrj.br, E-mail: ccalza@lin.ufrj.br, E-mail: henrique@lin.ufrj.br, E-mail: joseilson@lin.ufrj.br, E-mail: ricardo@lin.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear

    2013-07-01

    The scientific examination of artworks has gained increasing interest in the last years, allowing the characterization of materials and techniques employed by the artists. This analysis can be extremely valuable to conservation and restoration treatments. However, the fact that every artworks is a unique piece emphasizes the necessity of working with non-destructive techniques. Although radiography has been used in the technical examination of museum objects for many decades, digital radiography is rapidly becoming a preferred modality for this essential tool in the advanced examination of works of art. The ability to electronically combine images from the large painting into a single composite image file was extremely valuable and results in higher quality images than those achieved with conventional radiography. These images can be also processed and improved using adequate software. Additional advantages of digital radiography include the possibility of an almost immediate analysis of the results, use of an only recording film and absence of chemical processing. Radiographic imaging can be applied to the analysis of virtually all media including paintings, sculptures, woodworks, engravings, etc. This paper reports some case studies of the use of digital radiography in the study of paintings and sculptures, showing the feasibility and advantages of this technique for this kind of purpose. The radiographic images revealed the conservation state of the analyzed objects and various details of its execution in order to assist recently restoration processes. (author)

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

    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).

  10. Digital Radiography and Computed Tomography (DRCT) Product Improvement Plan (PIP)

    Tim Roney; Bob Pink; Karen Wendt; Robert Seifert; Mike Smith

    2010-12-01

    The Idaho National Laboratory (INL) has been developing and deploying x-ray inspection systems for chemical weapons containers for the past 12 years under the direction of the Project Manager for Non-Stockpile Chemical Materiel (PMNSCM). In FY-10 funding was provided to advance the capabilities of these systems through the DRCT (Digital Radiography and Computed Tomography) Product Improvement Plan (PIP), funded by the PMNSCM. The DRCT PIP identified three research tasks; end user study, detector evaluation and DRCT/PINS integration. Work commenced in February, 2010. Due to the late start and the schedule for field inspection of munitions at various sites, it was not possible to spend sufficient field time with operators to develop a complete end user study. We were able to interact with several operators, principally Mr. Mike Rowan who provided substantial useful input through several discussions and development of a set of field notes from the Pueblo, CO field mission. We will be pursuing ongoing interactions with field personnel as opportunities arise in FY-11.

  11. Image quality dependence on image processing software in computed radiography

    Lourens Jochemus Strauss

    2012-06-01

    Full Text Available Background. Image post-processing gives computed radiography (CR a considerable advantage over film-screen systems. After digitisation of information from CR plates, data are routinely processed using manufacturer-specific software. Agfa CR readers use MUSICA software, and an upgrade with significantly different image appearance was recently released: MUSICA2. Aim. This study quantitatively compares the image quality of images acquired without post-processing (flatfield with images processed using these two software packages. Methods. Four aspects of image quality were evaluated. An aluminium step-wedge was imaged using constant mA at tube voltages varying from 40 to 117kV. Signal-to-noise ratios (SNRs and contrast-to-noise Ratios (CNRs were calculated from all steps. Contrast variation with object size was evaluated with visual assessment of images of a Perspex contrast-detail phantom, and an image quality figure (IQF was calculated. Resolution was assessed using modulation transfer functions (MTFs. Results. SNRs for MUSICA2 were generally higher than the other two methods. The CNRs were comparable between the two software versions, although MUSICA2 had slightly higher values at lower kV. The flatfield CNR values were better than those for the processed images. All images showed a decrease in CNRs with tube voltage. The contrast-detail measurements showed that both MUSICA programmes improved the contrast of smaller objects. MUSICA2 was found to give the lowest (best IQF; MTF measurements confirmed this, with values at 3.5 lp/mm of 10% for MUSICA2, 8% for MUSICA and 5% for flatfield. Conclusion. Both MUSICA software packages produced images with better contrast resolution than unprocessed images. MUSICA2 has slightly improved image quality than MUSICA.

  12. Optimisation of computed radiography systems for chest imaging

    Alzimami, K. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)], E-mail: k.alzimami@surrey.ac.uk; Sassi, S. [Royal Marsden NHS Foundation Trust, Sutton, Surrey SM2 5PT (United Kingdom); Alkhorayef, M. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Britten, A.J. [Department of Medical Physics, St George' s Hospital, London SW17 0QT (United Kingdom); Spyrou, N.M. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2009-03-01

    The main thrust of this study is to investigate methods of optimising the radiation dose-image quality relationship in computed radiography (CR) systems for chest imaging. Specifically, this study investigates the possibility of reducing the patient radiation exposure through an optimal selection of tube filtration, exposure parameters and air gap technique, in parallel with a study of the image quality, particularly low contrast detail detectability, signal-to-noise ratio (SNR) and scatter fraction (SF). The CDRAD phantom was used to assess the quality of the CR images. Tissue equivalent Polystyrene blocks were placed in the front of the phantom as scattering material with thicknesses of 5 and 15 cm to simulate an adult chest and heart/diaphragm regions, respectively. A series of exposure techniques were used, including Cu filtration with various thicknesses of Cu in the presence and absence of an air gap, whilst the exposure was kept as constant as possible throughout. The estimated patient effective dose and skin entrance dose were calculated using the NRPB-SR262 X-ray dose calculation software. The results have shown that the low contrast-detail detectability in the lung and the heart/diaphragm regions improves when using an air gap and no Cu filtration, particularly at low kilovoltage (kVp). However, there is no significant difference in low contrast-detail in the absence or presence of a 0.2 mm Cu filtration. SF values for the lung and heart regions decrease when using both, the air gap technique and a 0.2 mm Cu filtration, particularly at low kVp. SNR values for the lung and heart regions improve when using a small Cu thickness. In conclusion, this investigation has shown that the quality of chest CR images could be improved by using an air gap technique and a 0.2 mm Cu filtration at low kVp, particularly at 99 kVp.

  13. Accuracy of digital peripical radiography and cone-beam computed tomography in detecting external root resorption

    Creanga, Adriana Gabriela [Division of Dental Diagnostic Science, Rutgers School of Dental Medicine, Newark (United States); Geha, Hassem; Sankar, Vidya; Mcmahan, Clyde Alex; Noujeim, Marcel [University of Texas Health Science Center San Antonio, San Antonio (United States); Teixeira, Fabrico B. [Dept. of Endodontics, University of Iowa, Iowa City (United States)

    2015-09-15

    The purpose of this study was to evaluate and compare the efficacy of cone-beam computed tomography (CBCT) and digital intraoral radiography in diagnosing simulated small external root resorption cavities. Cavities were drilled in 159 roots using a small spherical bur at different root levels and on all surfaces. The teeth were imaged both with intraoral digital radiography using image plates and with CBCT. Two sets of intraoral images were acquired per tooth: orthogonal (PA) which was the conventional periapical radiograph and mesioangulated (SET). Four readers were asked to rate their confidence level in detecting and locating the lesions. Receiver operating characteristic (ROC) analysis was performed to assess the accuracy of each modality in detecting the presence of lesions, the affected surface, and the affected level. Analysis of variation was used to compare the results and kappa analysis was used to evaluate interobserver agreement. A significant difference in the area under the ROC curves was found among the three modalities (P=0.0002), with CBCT (0.81) having a significantly higher value than PA (0.71) or SET (0.71). PA was slightly more accurate than SET, but the difference was not statistically significant. CBCT was also superior in locating the affected surface and level. CBCT has already proven its superiority in detecting multiple dental conditions, and this study shows it to likewise be superior in detecting and locating incipient external root resorption.

  14. Digital panoramic radiography versus cone beam computed tomography in the delineation of maxillomandibular tumors.

    Almeida-Barros, Renata Quirino de; Abilio, Vanessa Maria Freire; Yamamoto, Angela Toshie Araki; Melo, Daniela Pita de; Godoy, Gustavo Pina; Bento, Patricia Meira

    2015-01-01

    This research aimed to compare the efficacy of digital panoramic radiography (DPR) with that of cone beam computed tomography (CBCT) for delineation of odontogenic and nonodontogenic tumors. From November 2009 through March 2011, 23 tumors in the maxillomandibular complex were diagnosed by histopathological examination. All DPRs and CBCTs were obtained and analyzed by a single previously calibrated radiologist, who considered the following radiographic aspects: clarity of the lesion edges, relation with dental elements, involvement of adjacent anatomical structures, cortical bone expansion and disruption, and, if present, type of involved anatomical structures and site of bone expansion and disruption. Of 23 patients, 15 (65.2%) were male and 8 (34.8%) were female. The tumor was classified as odontogenic in 73.9% of patients and nonodontogenic in 26.1% of patients. Analysis revealed that 56.5% of the tumors were located in the mandible, 34.8% in the maxilla, and 8.7% in both arches. For all analyzed variables, CBCTs offered more accurate details than did DPRs. Panoramic radiography should not be the examination of choice to visualize lesions in the maxillomandibular complex.

  15. Digital Detectors: Computed Radiography (CR for All Radiologists

    Frans Dhaenens

    2007-08-01

    Full Text Available Introduction: Digital techniques in radiology have many advantages for radiologists, radiographers, patients, clinicians and hospital-operators from many perspectives: diagnostic quality, dose reduction, access to old and new images and reports via PACS, HIS and RIS."nRadiologists concentrate more and more on organs and pathology (super specialties rather than in modalities. Organ based radiology requires the integration of all modalities and has to cover large geographical regions to deliver expertise, as there few top-experts. This is only possible in the digital world of HICT (Health Information and Communication Technology, where digital detectors are the first step in a long chain of informatics."nToday most of the diagnostic imaging modalities (CT, MRI, US, PET,.. used in radiology are digital except plain film imaging. In order to digitize plain x-ray (also called General Radiology there is choice between Computed Radiography (CR based upon storage phosphor screens and DR (Digital Radiography based on "flat or panel" detectors. A large spectrum of applications and price ranges is available on the market."nTechnology: Both CR and DR rely on conversion and storage of x-ray energy in "pixel"-like elements in the detector. These detectors are linear (film is S-curved and have a enormous dynamic range (1 in 100.000 so no information is lost and they resist over- and under-exposure up to 4 times."n- In CR x-ray energy is stored into the phosphor-crystals and converted into visible light after stimulation by (laser light which is in turn captured and digitized by an optical system. Pixels (in size between 50 and 150 µm are one after one stimulated and translated into a digital image of millions of points. "n- In DR systems x-ray energy is converted in 2 or 3 steps into electrical charge that is stored in every pixel of the detector. These charges are digitized row after row to make a digital image. The conversion of the x-rays is done by a

  16. Observer variation for radiography, computed tomography, and magnetic resonance imaging of occult hip fractures

    Collin, David; Dunker, Dennis; Goethlin, Jan H (Dept. of Radiology, Sahlgrenska Univ. Hospital, Moelndal (Sweden)), email: david.collin@vgregion.se; Geijer, Mats (Center for Medical Imaging and Physiology, Skaane Univ. Hospital, Lund Univ., Lund (Sweden))

    2011-10-15

    Background Conventional radiography is insufficient for diagnosis in a small but not unimportant number of hip fractures, and secondary imaging with computed tomography (CT) or magnetic resonance imaging (MRI) is warranted. There are no convincing observer variation studies performed for conventional radiography or CT in occult fractures, and no large materials for MRI. Purpose To assess observer variation in radiography, CT and MRI of suspected occult, non-displaced hip fractures, and to evaluate to what extent observer experience or patient age may influence observer performance. Material and Methods A total of 375 patients after hip trauma where radiography was followed by CT or MRI to evaluate a suspected occult hip fracture were collected retrospectively from two imaging centers. After scoring by three observers with varying degrees of radiologic experience, observer variation was assessed by using linear weighted kappa statistics. Results For radiography, agreements between the three observers were moderate to substantial for intra capsular fractures, with kappa values in the ranges of 0.56-0.66. Kappa values were substantial for extracapsular fractures, in the ranges of 0.69-0.72. With increasing professional experience, fewer fractures were classified as equivocal at radiography. For CT and MRI, observer agreements were similar and almost perfect, with kappa values in the ranges of 0.85-0.97 and 0.93-0.97. Conclusion There were almost perfect observer agreements for CT and MRI in diagnosing non-displaced, occult hip fractures. Observer agreements for radiography were moderate to substantial, and observer experience influenced agreement only at radiography

  17. Computed radiography (FCR) with a dual side reading system. Comparison with conventional radiography for visualization of nodular lung cancers

    Ha-kawa, Shangkil; Yoshida, Tsunetaka; Sougawa, Mitsuharu; Harima, Yohko; Sawada, Satoshi [Kansai Medical Univ., Moriguchi, Osaka (Japan)

    2003-02-01

    To assess the diagnostic capability Fuji computed radiography (FCR) using a dual side reading system was compared to the conventional radiography using a film-screen system. Twenty-eight patients with lung cancer were examined with a new FCR system (FCR 5501D) and a conventional screen-film system concurrently. FCR utilizes a reading system that detects emissions from dual sides of imaging plate. Chest X-rays were obtained with same exposure factors in both systems. Image qualities of both systems were compared by two radiologists using a five-level score. There were no lesion that FCR images were inferior to film-screen images. The frequency of score +1 or +2 that FCR images were superior to film-screen images was 31% in large nodular shadows, 40% in accompanying shadows with a nodule, 67% of small nodular shadows, and 43% of the lymph node swelling in the hilum of the lung or mediastinum. In large nodular shadows which were the most frequent abnormality score +1 or +2 were observed in 43% of adenocarcinoma and 26% of squamous cell lung cancer. FCR with the dual side reading system is superior to the conventional screen-film system for visualization of nodular lung cancers. (author)

  18. Radiological protection procedures for industrial applications of computed radiography; Procedimentos de protecao radiologica em aplicacoes industriais da radiografia computadorizada

    Aquino, Josilto Oliveira de

    2009-03-15

    Due to its very particular characteristics, industrial radiography is responsible for roughly half of the relevant accidents in nuclear industry, in developed as well as in developing countries, according to the International Atomic Energy Agency (IAEA). Thus, safety and radiological protection in industrial gamma radiography have been receiving especial treatment by regulatory authorities of most Member States. The main objective of the present work was to evaluate, from the radioprotection point of view, the main advantages of computed radiography (CR) for filmless industrial radiography. In order to accomplish this, both techniques, i.e. conventional and filmless computed radiography were evaluated and compared through practical studies. After the studies performed at the present work it was concluded that computed radiography significantly reduces the inherent doses, reflecting in smaller restricted areas and costs, with consequent improvement in radiological protection and safety. (author)

  19. Standard practice for digital imaging and communication nondestructive evaluation (DICONDE) for computed radiography (CR) test methods

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice facilitates the interoperability of computed radiography (CR) imaging and data acquisition equipment by specifying image data transfer and archival storage methods in commonly accepted terms. This practice is intended to be used in conjunction with Practice E2339 on Digital Imaging and Communication in Nondestructive Evaluation (DICONDE). Practice E2339 defines an industrial adaptation of the NEMA Standards Publication titled Digital Imaging and Communications in Medicine (DICOM, see http://medical.nema.org), an international standard for image data acquisition, review, storage and archival storage. The goal of Practice E2339, commonly referred to as DICONDE, is to provide a standard that facilitates the display and analysis of NDE results on any system conforming to the DICONDE standard. Toward that end, Practice E2339 provides a data dictionary and a set of information modules that are applicable to all NDE modalities. This practice supplements Practice E2339 by providing information objec...

  20. First Results and Realization Status of a Proton Computed Radiography Device

    Sipala, V. [Dipt. di Fisica, Univ. degli Studi di Catania, via S. Sofia 64, I-95123, Catania (Italy); INFN, sezione di Catania, via S. Sofia 64, I-95123, Catania (Italy); Bruzzi, M. [Dipt. di Energetica, Univ. degli Studi di Firenze, via S. Marta 3, I-50139 Firenze (Italy); INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Bucciolini, M. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Dipt. di Fisiopatologia Clinica, Univ. degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); Candiano, G. [Lab. Nazionali del Sud-INFN, via S. Sofia 62, I-95123, Catania (Italy); Capineri, L. [Dipt. di Elettronica e Telecomunicazioni, Univ. degli Studi di Firenze, via S. Marta 3, I-50139 Firenze (Italy); Cirrone, G.A.P. [Lab. Nazionali del Sud-INFN, via S. Sofia 62, I-95123, Catania (Italy); Civinini, C. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Cuttone, G. [Lab. Nazionali del Sud-INFN, via S. Sofia 62, I-95123, Catania (Italy); Lo Presti, D. [Dipt. di Fisica, Univ. degli Studi di Catania, via S. Sofia 64, I-95123, Catania (Italy); INFN, sezione di Catania, via S. Sofia 64, I-95123, Catania (Italy); Marrazzo, L. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Dipt. di Fisiopatologia Clinica, Univ. degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); Menichelli, D. [Dipt. di Energetica, Univ. degli Studi di Firenze, via S. Marta 3, I-50139 Firenze (Italy); INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Randazzo, N. [INFN, sezione di Catania, via S. Sofia 64, I-95123, Catania (Italy); Talamonti, C. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Dipt. di Fisiopatologia Clinica, Univ. degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy)

    2009-12-15

    The PRIMA (PRoton IMAging) collaboration, supported by INFN and MIUR, is realizing a proton Computed Radiography device suitable to acquire the single proton with 1MHz rate for application in proton therapy. Its design and the first results obtained are presented.

  1. Computer-aided diagnosis of pulmonary diseases using x-ray darkfield radiography

    Einarsdottir, Hildur; Yaroshenko, Andre; Velroyen, Astrid;

    2015-01-01

    In this work we develop a computer-aided diagnosis (CAD) scheme for classification of pulmonary disease for grating-based x-ray radiography. In addition to conventional transmission radiography, the grating-based technique provides a dark-field imaging modality, which utilizes the scattering...... of three stages: (i) automatic lung segmentation; (ii) feature extraction from lung shape and dark-field image intensities; (iii) classification between healthy, emphysema and fibrosis lungs. A study of 102 mice was conducted with 34 healthy, 52 emphysema and 16 fibrosis subjects. Each image was manually...

  2. Imaging suspected cervical spine injury: Plain radiography or computed tomography? Systematic review

    Cain, Gavin [Diagnostic Radiographer, Colchester Hospital University NHS Foundation Trust, Colchester General Hospital, Turner Road, Colchester, CO4 5JL Essex (United Kingdom)], E-mail: gavincain8@hotmail.com; Shepherdson, Jane; Elliott, Vicki; Svensson, Jon [Faculty of Health and Social Care, Anglia Ruskin University, East Road, Cambridge, CB1 9PT Cambridgeshire (United Kingdom); Brennan, Patrick [UCD School of Medicine and Medical Sciences, Health Science Building, Belfield, Dublin 4 (Ireland)

    2010-02-15

    Aim: (1) to establish which modality offers the greatest accuracy in the detection of cervical spine injury (CSI) Following trauma: plain radiography or computed tomography (CT), and (2) make an evidence-based recommendation for the initial imaging modality of choice. Method: A systematic literature review was performed to identify primary research studies which compare the diagnostic accuracy of plain radiography and CT with the results of a reference standard in the detection of CSI. A search of MEDLINE, EMBASE, CINAHL, Science Direct and Pubmed Central databases was conducted. Results: Ten studies were identified. Critical appraisal identified limitations among all studies. There was heterogeneity in the sensitivity estimates for plain radiography, whereas estimates for CT were consistently high. Examination of the reported sensitivities shows that CT outperforms plain radiography in the detection of CSI. Conclusion: CT is superior to plain radiography in the detection of CSI. However, the optimal imaging strategy depends on the patients' relative risk of injury. If at high-risk cervical CT is indicated. If at low-risk the increased cost and radiation exposure mean that screening CT may not be warranted, good-quality plain radiographs are sufficient.

  3. SisRadiologia: a new software tool for analysis of radiological accidents and incidents in industrial radiography

    Lima, Camila M. Araujo; Silva, Francisco C.A. da, E-mail: araujocamila@yahoo.com.br, E-mail: dasilva@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Araujo, Rilton A., E-mail: consultoria@maximindustrial.com.br [Maxim Industrial Assessoria TI, Rio de Janeiro, RJ (Brazil)

    2013-07-01

    According to the International Atomic Energy Agency (IAEA), many efforts have been made by Member states, aiming a better control of radioactive sources. Accidents mostly happened in practices named as high radiological risk and classified by IAEA in categories 1 and 2, being highlighted those related to radiotherapy, large irradiators and industrial radiography. Worldwide, more than 40 radiological accidents have been recorded in the industrial radiography. Worldwide, more than 40 radiological accidents have been recorded in the industrial radiography area, involving 37 workers, 110 members of the public and 12 fatalities. Records display 5 severe radiological accidents in industrial radiography activities in Brazil, in which 7 workers and 19 members of the public were involved. Such events led to hands and fingers radiodermatitis, but to no death occurrence. The purpose of this study is to present a computational program that allows the data acquisition and recording in the company, in such a way to ease a further detailed analysis of radiological event, besides providing the learning cornerstones aiming the avoidance of future occurrences. After one year of the 'Industrial SisRadiologia' computational program application - and mostly based upon the workshop about Analysis and Dose Calculation of Radiological Accidents in Industrial Radiography (Workshop sobre Analise e Calculo de dose de acidentes Radiologicos em Radiografia Industrial - IRD 2012), in which several Radiation Protection officers took part - it can be concluded that the computational program is a powerful tool to data acquisition, as well as, to accidents and incidents events recording and surveying in Industrial Radiography. The program proved to be efficient in the report elaboration to the Brazilian Regulatory Authority, and very useful in workers training to fix the lessons learned from radiological events.

  4. Diagnostic sensitivity of ultrasound, radiography and computed tomography for gender determination in four species of lizards.

    Di Ianni, Francesco; Volta, Antonella; Pelizzone, Igor; Manfredi, Sabrina; Gnudi, Giacomo; Parmigiani, Enrico

    2015-01-01

    Gender determination is frequently requested by reptile breeders, especially for species with poor or absent sexual dimorphism. The aims of the current study were to describe techniques and diagnostic sensitivities of ultrasound, radiography, and computed tomography for gender determination (identification of hemipenes) in four species of lizards. Nineteen lizards of known sex, belonging to four different species (Pogona vitticeps, Uromastyx aegyptia, Tiliqua scincoides, Gerrhosaurus major) were prospectively enrolled. With informed owner consent, ultrasound, noncontrast CT, contrast radiography, and contrast CT (with contrast medium administered into the cloaca) were performed in conscious animals. Imaging studies were reviewed by three different operators, each unaware of the gender of the animals and of the results of the other techniques. The lizard was classified as a male when hemipenes were identified. Nineteen lizards were included in the study, 10 females and nine males. The hemipenes were seen on ultrasound in only two male lizards, and appeared as oval hypoechoic structures. Radiographically, hemipenes filled with contrast medium appeared as spindle-shaped opacities. Noncontrast CT identified hemipenes in only two lizards, and these appeared as spindle-shaped kinked structures with hyperattenuating content consistent with smegma. Hemipenes were correctly identified in all nine males using contrast CT (accuracy of 100%). Accuracy of contrast radiography was excellent (94.7%). Accuracy of ultrasound and of noncontrast CT was poor (64.3% and 63.1%, respectively). Findings from the current study supported the use of contrast CT or contrast radiography for gender determination in lizards.

  5. Comparing intraoral radiography and computed tomography for detecting radiographic signs of periodontitis and endodontic disease in dogs: an agreement study.

    Robert David Campbell; Santiago Peralta; Nadine Fiani; Peter Vincent Scrivani

    2016-01-01

    Objective: To determine whether computed tomography and intraoral radiography are interchangeable for detecting signs of periodontitis and endodontic disease in dogs. Materials and Methods: An agreement study was performed using 40 dogs that previously underwent intraoral radiography and computed tomography during the same anesthetic episode. Images of each tooth were examined by two blinded observers for signs of periodontitis and/or endodontic disease. Agreement between imaging modalities a...

  6. COMPARATIVE STUDY OF CLINICAL MANIFESTATION, PLAIN FILM RADIOGRAPHY AND COMPUTED TOMOGRAPHY FOR DIAGNOSIS OF MAXILLOFACIAL TRAUMA

    Amit

    2014-09-01

    Full Text Available OBJECTIVE: Maxillofacial injuries are one of commonest injuries encountered. Roentgenographic evaluation of maxillofacial trauma is of prime importance for diagnosis and treatment of these injuries. STUDY DESIGN: Forty patients were evaluated in prospective four year study. We studied and evaluated the demography and diagnostic efficacy of clinical, plain radiography, and computed scan in maxillofacial trauma. RESULT: Road traffic accidents were commonest cause of maxillofacial injuries. Patients having multiple fractures, mandibular fractures was commonest. CONCLUSION: Computed tomography proved a useful adjunct in mid facial trauma.

  7. 新生儿肺透明膜病的计算机X线摄影表现与临床分析%Clinical analysis and computed radiography showed of pulmonary hyaline membrane disease of the newborn

    刘正奎

    2014-01-01

    目的:探讨新生儿肺透明膜病的计算机X线摄影表现与临床分析。方法:2011年1月-2013年12月收治使用计算机X线摄影进行诊断的新生儿肺透明膜病患儿80例,根据新生儿肺透明膜病X线的表现,对X线与临床因素之间的关系进行分析。结果:80例新生儿肺透明膜病中,Ⅰ级、Ⅱ级、Ⅲ级、Ⅳ级分别有8例、21例、43例、8例,所占比例分别是10.00%、26.25%、53.75、10.00%。52例患儿出现并发症,并发症发生率65%,22例肺炎,8例缺血缺氧脑病,2例颅内出血,4例肺出血,6例气胸,7例胸腔积液,2例先天性心脏病,1例支气管肺发育不良。其中13例患儿死亡,死亡率20%。结论:新生儿肺透明膜病的病情发展快,且多发合并症,死亡率较高,因此需要尽早确诊,以得到及时有效的治疗,尤其在早产儿、低体重儿中更应注意此病。%Objective:To investigate the clinical analysis and computed radiography showed of pulmonary hyaline membrane disease of the newborn.Methods:80 newborn with hyaline membrane disease who diagnosed by the computer X-ray photography were selected from January 2011 to December 2013.We analyzed the relationship between X-ray and clinical factors according to the x-ray performance of neonatal hyaline membrane disease.Results:80 cases of neonatal pulmonary hyaline membrane disease, grade Ⅰ, Ⅱ, Ⅲ, Ⅳ there were 8 cases,21 cases,43 cases,8 cases respectively;the proportions were 10.00% ,26.25% ,53.75% , 10.00% respectively.52 cases(65%)had complications;22 cases of pneumonia;8 cases of hypoxic ischemic encephalopathy;2 cases of intracranial hemorrhage;4 cases with pulmonary hemorrhage;6 cases of pneumothorax;pleural effusion in 7 cases;2 cases of congenital heart disease;1 case of bronchopulmonary dysplasia.Among them 13 cases died,and the mortality was 20%.Conclusion:Neonatal hyaline membrane disease develops fast,and has many complications

  8. Comparing Intraoral Radiography and Computed Tomography for Detecting Radiographic Signs of Periodontitis and Endodontic Disease in Dogs: An Agreement Study

    Campbell, Robert D.; Peralta, Santiago; Fiani, Nadine; Scrivani, Peter V.

    2016-01-01

    Objective To determine whether computed tomography (CT) and intraoral radiography are interchangeable for detecting signs of periodontitis and endodontic disease in dogs. Materials and methods An agreement study was performed using 40 dogs that previously underwent intraoral radiography and CT during the same anesthetic episode. Images of each tooth were examined by two blinded observers for signs of periodontitis and/or endodontic disease. Agreement between imaging modalities and between obs...

  9. Comparative Evaluation of Chronic Rhinosinusitis Patients by Conventional Radiography, Computed Tomography and Diagnostic Nasal Endoscopy (DNE).

    Srivastava, Mohit; Tyagi, Sushant; Kumar, Lalit

    2016-06-01

    Chronic rhinosinusitis is a common condition in medical practice. It is defined as inflammation of the mucosa of nose and paranasal sinuses, the fluids within these cavities, and/or the underlying bone that has been present with or without treatment for at least 12 weeks duration. In 1997, a detailed definition of the syndrome was developed by the Rhinosinusitis Task Force of the American Academy of Otolaryngology-Head and Neck Surgery, consisting of the major and minor diagnostic criterias. To study the role of conventional radiography, nasal endoscopy and computed tomography in the early diagnosis of chronic rhinosinusitis. The study was carried out in the Department of Otorhinolaryngology, Saraswati Institute of Medical Sciences. A total of 100 patients with clinical evidence of sinonasal diseases were evaluated with conventional radiography, Nasal endoscopy and computed tomographic evaluation. Out of 100 patients; 58 were male and 42 were female. M:F ratio = 1.38:1. Majority of the patients were being in the age group of 21-30 years (30 %). The most common finding on conventional radiography was opacification of maxillary sinus (42 %) followed mucosal thickening (26 %), haziness of the maxillary sinus (19 %) followed by air-fluid level (13 %). Five basic radiological patterns of sinonasal inflammatory disease are identified among 100 patients. These were (1) Infundibular 16 %, (2) Ostiomeatal unit 32 %, (3) Sphenoethmoidal 8 %, (4) Sinonasal polyposis 28 %, (5) Unclassified 16 %. The sensitivity and specificity of plain film radiography for detecting sinus opacifications was unacceptably low for paranasal sinuses, hence conventional radiography should not be used as a single diagnostic tool in preoperative evaluation. Nasal endoscopy having sensitivity and specificity almost as good as CT scanning, and being an outpatient procedure may reduce unnecessary diagnostic CT scanning procedures. It allows an unparalleled vision with brilliant

  10. Análise de carcinomas epidermóides por meio de radiografia panorâmica e tomografia computadorizada Analysis of squamous cell carcinomas by means of panoramic radiography and computed tomography

    Amanda Cáceres PEREIRA

    2001-12-01

    Full Text Available Este trabalho teve como objetivo correlacionar aspectos radiográficos como, localização e extensão do tumor, infiltração óssea e de tecidos moles e destruição das corticais, obtidos nas radiografias panorâmicas com os encontrados nas tomografias computadorizadas (TCs. Os aspectos radiográficos de 48 pacientes com diagnóstico histopatológico de carcinomas epidermóides, localizados em várias regiões do complexo buco-maxilo-facial, foram analisados por 4 radiologistas. As radiografias panorâmicas e as tomografias computadorizadas foram realizadas nos hospitais e clínicas da Universidade de Iowa (EUA, FUNDECTO - USP e Hospital Universitário da Universidade de São Paulo (SP, Brasil. Como resultados, obtivemos a grande limitação da radiografia panorâmica em determinar a localização e extensão do tumor, com delimitações bastante imprecisas da lesão. Já as TCs ofereceram resultados mais direcionados como: invasão do tumor em direção a estruturas moles adjacentes, extensão da destruição óssea, bem como a profundidade da lesão, que foram confirmados com os achados cirúrgicos. Concluímos que a tomografia computadorizada demonstrou ser uma técnica bastante sensível na detecção do comprometimento ósseo e do envolvimento de tecidos moles, proporcionando, assim, o auxílio no diagnóstico e no planejamento do tratamento. No entanto, a radiografia panorâmica foi muito pouco sensível e eficaz, por mostrar apenas margens imprecisas e pouco nítidas da lesão, não avaliando o envolvimento de tecidos moles.The purpose of this work was to compare radiographic findings, such as localization and extension of tumors toward the bone and soft tissues, in panoramic radiography and computed tomography (CT. Four radiologists assessed the radiographic findings of 48 patients with the histopathological diagnosis of squamous cell carcinoma in different sites of the maxillofacial region. Panoramic radiographs and computed

  11. Increasing mobile radiography productivity.

    Wong, Edward; Lung, Ngan Tsz; Ng, Kris; Jeor, Patrick

    2013-01-01

    Mobile radiography using computed radiography (CR) cassettes is a common equipment combination with a workflow bottleneck limited by location of CR readers. Advent of direct digital radiography (DDR) mobile x-ray machines removes this limitation by immediate image review and quality control. Through the use of key performance indicators (KPIs), the increase in efficiency can be quantified.

  12. An investigation of automatic exposure control calibration for chest imaging with a computed radiography system.

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

    2014-05-07

    The purpose of this study was to examine the use of three physical image quality metrics in the calibration of an automatic exposure control (AEC) device for chest radiography with a computed radiography (CR) imaging system. The metrics assessed were signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and mean effective noise equivalent quanta (eNEQm), all measured using a uniform chest phantom. Subsequent calibration curves were derived to ensure each metric was held constant across the tube voltage range. Each curve was assessed for its clinical appropriateness by generating computer simulated chest images with correct detector air kermas for each tube voltage, and grading these against reference images which were reconstructed at detector air kermas correct for the constant detector dose indicator (DDI) curve currently programmed into the AEC device. All simulated chest images contained clinically realistic projected anatomy and anatomical noise and were scored by experienced image evaluators. Constant DDI and CNR curves do not appear to provide optimized performance across the diagnostic energy range. Conversely, constant eNEQm and SNR do appear to provide optimized performance, with the latter being the preferred calibration metric given as it is easier to measure in practice. Medical physicists may use the SNR image quality metric described here when setting up and optimizing AEC devices for chest radiography CR systems with a degree of confidence that resulting clinical image quality will be adequate for the required clinical task. However, this must be done with close cooperation of expert image evaluators, to ensure appropriate levels of detector air kerma.

  13. Analysis of sculptures using XRF and X-ray radiography

    Calza, C.; Oliveira, D. F.; Freitas, R. P.; Rocha, H. S.; Nascimento, J. R.; Lopes, R. T.

    2015-11-01

    This work reports the analysis of two sacred images on polychrome wood using X-ray Radiography and Energy Dispersive X-Ray Fluorescence. The first case is the analysis of a sculpture portraying Saint Sebastian, the patron saint of Rio de Janeiro, which is considered the second most ancient sacred image of Brazil. This sculpture was made in Portugal and was transported to Brazil by Estácio Sá, founder of the city of Rio de Janeiro, in 1565. Nowadays, it is located on the main altar of the Church of Capuchin Friars. The second case is the analysis of a sculpture representing Our Lady of Conception, which is located in the D. João VI Museum (EBA/UFRJ, Rio de Janeiro). The objective of these analyses was to evaluate the general conditions of the sculptures, identifying possible problems and internal damages, areas that revealed signs of previous retouchings and the materials and pigments employed by the artists, in order to assist its restoration procedures. EDXRF measurements were carried out with a portable system, developed at the Nuclear Instrumentation Laboratory, consisting of a Si-PIN XR-100CR detector from Amptek and an Oxford TF3005 X-ray tube with W anode. An X-ray source, a CR System GE CR50P and IP detectors were used to perform the radiographs. The XRF analysis of the sculptures identified the original pigments in both cases and the radiographic images revealed details of the manufacture; restored regions; extensive use of lead white; presence of cracks on the wood; use of nails and spikes, etc.

  14. Vibration Analysis of Digital Radiography System for Large Container Inspection

    黄松岭; 李路明; 周立业; 向新程; 安继刚

    2003-01-01

    The cantilever vibration characteristics of a digital radiography system were analyzed to predict the effect of vibration on the performance of a mobile container inspection system. The static deformation,vibration mode and natural frequency of the cantilever of the digital radiography system were calculated with the ALGOR Finite Element System to verify the strength and rigidity of the cantilever. The maximum amplitude of the cantilever vibration occurs as it starts accelerating. The predictions show good agreement with test results, indicating that the finite element model of the cantilever structure accurately models the mechanical characteristics.

  15. Basilar skull fracture in a Thoroughbred colt: Radiography or computed tomography?

    Chee Kin Lim

    2013-04-01

    Full Text Available A two-year-old Thoroughbred colt was presented to the Equine Clinic, Onderstepoort Veterinary Academic Hospital for head trauma after rearing and falling backwards, hitting his head on the ground. Following medical therapy for acute onset neurological impairment secondary to a suspected basilar skull fracture, the horse was anaesthetised and computed tomography of the skull was performed. A diagnosis of a comminuted basilar skull fracture was made and skull radiographs were taken for comparison. The horse was subsequently euthanased owing to the poor prognosis; necropsy findings were compatible with imaging findings. The value and limitation of computed tomography versus radiography for the diagnosis of basilar skull fracture are discussed in this report. Introduction

  16. Basilar skull fracture in a Thoroughbred colt: Radiography or computed tomography?

    Chee Kin Lim

    2013-02-01

    Full Text Available A two-year-old Thoroughbred colt was presented to the Equine Clinic, Onderstepoort Veterinary Academic Hospital for head trauma after rearing and falling backwards, hitting his head on the ground. Following medical therapy for acute onset neurological impairment secondary to a suspected basilar skull fracture, the horse was anaesthetised and computed tomography of the skull was performed. A diagnosis of a comminuted basilar skull fracture was made and skull radiographs were taken for comparison. The horse was subsequently euthanased owing to the poor prognosis; necropsy findings were compatible with imaging findings. The value and limitation of computed tomography versus radiography for the diagnosis of basilar skull fracture are discussed in this report.

  17. Digital Radiography and Computed Tomography Project -- Fully Integrated Linear Detector ArrayStatus Report

    Tim Roney; Robert Seifert; Bob Pink; Mike Smith

    2011-09-01

    The field-portable Digital Radiography and Computed Tomography (DRCT) x-ray inspection systems developed for the Project Manager for NonStockpile Chemical Materiel (PMNSCM) over the past 13 years have used linear diode detector arrays from two manufacturers; Thomson and Thales. These two manufacturers no longer produce this type of detector. In the interest of insuring the long term viability of the portable DRCT single munitions inspection systems and to improve the imaging capabilities, this project has been investigating improved, commercially available detectors. During FY-10, detectors were evaluated and one in particular, manufactured by Detection Technologies (DT), Inc, was acquired for possible integration into the DRCT systems. The remainder of this report describes the work performed in FY-11 to complete evaluations and fully integrate the detector onto a representative DRCT platform.

  18. A case of fatal sigmoid volvulus visualized on postmortem radiography: The importance of image optimization with multidetector computed tomography.

    Usui, Akihito; Kawasumi, Yusuke; Hosokai, Yoshiyuki; Ishizuka, Yuya; Ikeda, Tomoya; Saito, Haruo; Funayama, Masato

    2016-03-01

    This report describes the case of a man who developed fatal sigmoid volvulus that was identified on postmortem radiography before forensic autopsy. Postmortem radiography is useful for visualizing the body prior to autopsy. We discuss postmortem multidetector computed tomography that was tailored for optimum image quality to allow reconstruction of the fatal findings in multiple axes and in three dimensions, helping to pinpoint the anatomical sites of interest. This involves techniques such as manipulation of the scanning beam pitch and overlapping CT section acquisition. These techniques are best performed by personnel with CT technology training.

  19. Computer-aided diagnosis of pulmonary diseases using x-ray darkfield radiography

    Einarsdóttir, Hildur; Yaroshenko, Andre; Velroyen, Astrid; Bech, Martin; Hellbach, Katharina; Auweter, Sigrid; Yildirim, Önder; Meinel, Felix G.; Eickelberg, Oliver; Reiser, Maximilian; Larsen, Rasmus; Kjær Ersbøll, Bjarne; Pfeiffer, Franz

    2015-12-01

    In this work we develop a computer-aided diagnosis (CAD) scheme for classification of pulmonary disease for grating-based x-ray radiography. In addition to conventional transmission radiography, the grating-based technique provides a dark-field imaging modality, which utilizes the scattering properties of the x-rays. This modality has shown great potential for diagnosing early stage emphysema and fibrosis in mouse lungs in vivo. The CAD scheme is developed to assist radiologists and other medical experts to develop new diagnostic methods when evaluating grating-based images. The scheme consists of three stages: (i) automatic lung segmentation; (ii) feature extraction from lung shape and dark-field image intensities; (iii) classification between healthy, emphysema and fibrosis lungs. A study of 102 mice was conducted with 34 healthy, 52 emphysema and 16 fibrosis subjects. Each image was manually annotated to build an experimental dataset. System performance was assessed by: (i) determining the quality of the segmentations; (ii) validating emphysema and fibrosis recognition by a linear support vector machine using leave-one-out cross-validation. In terms of segmentation quality, we obtained an overlap percentage (Ω) 92.63  ±  3.65%, Dice Similarity Coefficient (DSC) 89.74  ±  8.84% and Jaccard Similarity Coefficient 82.39  ±  12.62%. For classification, the accuracy, sensitivity and specificity of diseased lung recognition was 100%. Classification between emphysema and fibrosis resulted in an accuracy of 93%, whilst the sensitivity was 94% and specificity 88%. In addition to the automatic classification of lungs, deviation maps created by the CAD scheme provide a visual aid for medical experts to further assess the severity of pulmonary disease in the lung, and highlights regions affected.

  20. Accuracy of chest radiography versus chest computed tomography in hemodynamically stable patients with blunt chest trauma

    Chardoli Mojtaba

    2013-12-01

    Full Text Available 【Abstract】 Objective: Thoracic injuries are respon- sible for 25% of deaths of blunt traumas. Chest X-ray (CXR is the first diagnostic method in patients with blunt trauma. The aim of this study was to detect the accuracy of CXR versus chest computed tomograpgy (CT in hemodynami- cally stable patients with blunt chest trauma. Methods: Study was conducted at the emergency department of Sina Hospital from March 2011 to March 2012. Hemodynamically stable patients with at least 16 years of age who had blunt chest trauma were included. All patients underwent the same diagnostic protocol which consisted of physical examination, CXR and CT scan respectively. Results: Two hundreds patients (84% male and 16% female were included with a mean age of (37.9±13.7 years. Chin J Traumatol 2013;16(6:351-354 Rib fracture was the most common finding of CXR (12.5% and CT scan (25.5%. The sensitivity of CXR for hemothorax, thoracolumbar vertebra fractures and rib fractures were 20%, 49% and 49%, respectively. Pneumothorax, foreign body, emphysema, pulmonary contusion, liver hematoma and ster- num fracture were not diagnosed with CXR alone. Conclusion: Applying CT scan as the first-line diag- nostic modality in hemodynamically stable patients with blunt chest trauma can detect pathologies which may change management and outcome. Key words: Radiography; Thoracic injuries; Tomography, X-ray computed

  1. Objective measures of quality assurance in a computed radiography-based radiology department

    Willis, Charles E.; Leckie, Robert G.; Carter, Jon R.; Williamson, Morgan P.; Scotti, Stephen D.; Norton, Gary S.

    1995-05-01

    Parameters are needed to assess quality assurance in a radiology department where computed radiography (CR) is the principal means of image acquisition. Laser-printed computed radiographs were collected for all patients examined over a period of several days. A sample of 1200 was sorted by subject anatomy and the associated exam information was entered into an EXCEL spreadsheet. Sensitivity (S) numbers were sorted into histogram and analyzed using standard descriptive statistics. Each film was over-read by a board-certified radiologist to assess whether the image was diagnostic and to determine if there were pathologic findings. A significant proportion of images were acquired using inappropriate menu codes. The histogram of S numbers for a given menu code describes a log normal distribution. The S number depends on the technologist's ability to control the technique. A significant proportion of the images were deemed non diagnostic, and many correlated to excessive S numbers. Some were a result of mispositioning. The S number is a valid retrospective measure of radiographic quality assurance. Departments using CR should strive for control on menu codes selected and S numbers produced. Such data should be available from PACS databases.

  2. Influence of estrogen deficiency and tibolone therapy on trabecular and cortical bone evaluated by computed radiography system in rats

    Carvalho, Ana Carolina Bergmann de; Henriques, Helene Nara [Postgraduate Program in Pathology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Fernandes, Gustavo Vieira Oliveira [Postgraduate Program in Medical Sciences, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Lima, Inaya; Oliveira, Davi Ferreira de; Lopes, Ricardo Tadeu [Nuclear Engineering Program, Federal University of Rio de Janeiro (UFRJ), RJ (Brazil); Pantaleao, Jose Augusto Soares [Maternal and Child Department, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Granjeiro, Jose Mauro [Department of Cellular and Molecular Biology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Silva, Maria Angelica Guzman [Department of Pathology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2012-03-15

    Purpose: To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS). Methods: The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T) while the other did not (OVX), those groups were compared to a control group (C) not ovariectomized. Tibolone administration (1 mg/day) began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographs of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at P<0.05%. Results: Tibolone administration was shown to be beneficial only in the densitometric analysis of the femoral head, performing higher optical density compared to OVX. No difference was found in cortical bone thickness. Conclusion: Ovariectomy caused bone loss in the analyzed regions and tibolone administered in high doses over a long period showed not to be fully beneficial, but preserved bone mass in the femoral head. (author)

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

    Yu, Wei; Feng Feng; Yang Hongzen; Jiang Ming [Department of Radiology, Peking Union Medical College Hospital, Beijing (China); Dion, E.; Genant, H.K. [Department of Radiology, Musculoskeletal Section and Osteoporosis and Arthritis Research Group, University of California San Francisco, CA 94143-0628 (United States)

    1998-06-01

    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.) With 5 figs., 4 tabs., 36 refs.

  4. Radiologic analysis of femoral acetabular impingement: from radiography to MRI

    Dwek, Jerry R. [University of California at San Diego, Department of Radiology, Rady Children' s Hospital and Health Center, San Diego, CA (United States); San Diego Imaging, San Diego, CA (United States); Monazzam, Shafagh [Rady Children' s Hospital and Health Center, Department of Orthopedics, San Diego, CA (United States); Chung, Christine B. [University of California at San Diego, Department of Radiology, San Diego, CA (United States)

    2013-03-15

    Femoral acetabular impingement is a set of morphologic abnormalities that are considered to be a major cause of degenerative disease in the hip joint. Early changes are already present in adolescence when it is the pediatric radiologist who must assess current damage with the aim of averting progression to more severe and debilitating osteoarthritis. A multimodality approach is used for diagnosis, that includes conventional radiography and CT to assess the osseous structures. MR arthrography is the primary advanced imaging modality for assessment of morphologic changes as well as injuries of the labrum and articular cartilage. Details of radiologic imaging are offered to guide the radiologist and provide an avenue for the accurate description of the osseous and articular alterations and injury. (orig.)

  5. Measurement of image quality according to the time of computed radiography system

    Son, Soon Yong; Choi, Kwan Woo [Dept. of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Kim, Jung Min [Dept. of College of Health Science, Radiologic Science, Korea University, Seoul (Korea, Republic of); and others

    2015-12-15

    The regular quality assurance (RQA) of X-ray images is essential for maintaining a high accuracy of diagnosis. This study was to evaluate the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE) of a computed radiography (CR) system for various periods of use from 2006 to 2015. We measured the pre-sampling MTF using the edge method and RQA 5 based on commission standard international electro-technical commission (IEC). The spatial frequencies corresponding to the 50% MTF for the CR systems in 2006, 2009, 2012 and 2015 were 1.54, 1.14, 1.12, and 1.38 mm-1, respectively and the10 % MTF for 2006, 2009, 2012, and 2015 were 2.68, 2.44, 2 .44, and 2.46mm-1, respectively. In the NPS results, the CR systems showed the best noise distribution in 2006, and with the quality of distributions in the order of 2015, 2009, and 2012. At peak DQE and DQE at 1 mm-1, the CR systems showed the best efficiency in 2006, and showed better efficiency in order of 2015, 2009, and 2012. Because the eraser lamp in the CR systems was replaced, the image quality in 2015 was superior to those in 2009 and 2012. This study can be incorporated into used in clinical QA requiring performance and evaluation of the performance of the CR systems.

  6. Assessment of maxillary third molars with panoramic radiography and cone-beam computed tomography

    Jung, Yun Hoa; Cho, Bong Hae [Dept.of Oral and Maxillofacial Radiology, School of Dentistry, Pusan National University, Yangsan (Korea, Republic of)

    2015-12-15

    This study investigated maxillary third molars and their relation to the maxillary sinus using panoramic radiography and cone-beam computed tomography (CBCT). A total of 395 maxillary third molars in 234 patients were examined using panoramic radiographs and CBCT images. We examined the eruption level of the maxillary third molars, the available retromolar space, the angulation, the relationship to the second molars, the number of roots, and the relationship between the roots and the sinus. Females had a higher frequency of maxillary third molars with occlusal planes apical to the cervical line of the second molar (Level C) than males. All third molars with insufficient retromolar space were Level C. The most common angulation was vertical, followed by buccoangular. Almost all of the Level C molars were in contact with the roots of the second molar. Erupted teeth most commonly had three roots, and completely impacted teeth most commonly had one root. The superimposition of one third of the root and the sinus floor was most commonly associated with the sinus floor being located on the buccal side of the root. Eruption levels were differently distributed according to gender. A statistically significant association was found between the eruption level and the available retromolar space. When panoramic radiographs showed a superimposition of the roots and the sinus floor, expansion of the sinus to the buccal side of the root was generally observed in CBCT images.

  7. Investigation of optimum energies for chest imaging using film-screen and computed radiography.

    Honey, I D; Mackenzie, A; Evans, D S

    2005-05-01

    The purpose of the study was to compare the image quality of film-screen (FS) and computed radiography (CR) for adult chest examinations across a range of beam energies. A series of images of the CDRAD threshold contrast detail detection phantom were acquired for a range of tube potential and exposure levels with both CR and FS. The phantom was placed within 9 cm of Perspex to provide attenuation and realistic levels of scatter in the image. Hardcopy images of the phantom were scored from a masked light-box by two scorers. Threshold contrast indices were used to calculate a visibility index (VI). The relationships between dose and image quality for CR and for FS are fundamentally different. The improvements in VIs obtained using CR at 75 kVp and 90 kVp were found to be statistically significant compared with 125 kVp at matched effective dose levels. The relative performance of FS and CR varies as a function of energy owing to the different k-edges of each system. When changing from FS to CR, the use of lower tube potentials may allow image quality to be maintained whilst reducing effective dose. A tube voltage of 90 kVp is indicated by this work, but may require clinical verification.

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

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

    2002-09-01

    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 (1024x1536x8 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 ( pscore of "microcalcification" on CR hard-copy was significantly lower than on the other three viewing methods ( pfilm 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.

  9. The role of high-energy computed radiography (CR) in radiotherapy

    LI Zhaobin; SUN Yi; LU Yaohong; FU Shen

    2009-01-01

    Computed radiography (CR) imaging has high irradiation tolerance and it is easy to archive CR images along with other image information by Digital Imaging and Communications in Medicine (DICOM) format,and to process them.CR can be used in radiation Quality Control (QC) task and verification of treatment setting-up.In this paper,the role of high-energy CR in radiation oncology is studied.The patients were imaged by CR system and EPID before radiotherapy.All verification images were acquired with 1-2 MU (Monitor Unit) using 6 MV X-rays.QC for a tinac was done with film and high-energy CR to collect the data on daily,weekly and monthly basis.The QC included Multileaf Collimators (MLC) calibration and mechanical iso-centre check.CR was also adapted to verify patient position,the film was used to compare with digitally reconstructed radiographs (DRR) and portal image from EPID.Treatment setting-up was verified based on the result of comparison.High quality verification images cou ld beacquired by the CR system.Comparing to EPID,the results showed that the system was suitable for practical use to acquire daffy verification images,and it was useful to fulfill part of quality assurance (QA) in radiation oncology.The quality of image acquired by the high-energy CR system is comparable or even better than DRRs and portal images.The final treatment set-up for the patients could be verified more accurately with the CR system.

  10. Extremity exams optimization for computed radiography; Otimizacao de exames de extremidade para radiologia computadorizada

    Pavan, Ana Luiza M.; Alves, Allan Felipe F.; Velo, Alexandre F.; Miranda, Jose Ricardo A., E-mail: analuiza@ibb.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Instituto de Biociencias. Departamento de Fisica e Biofisica; Pina, Diana R. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Faculdade de Medicina. Departamento de Doencas Tropicais e Diagnostico por Imagem

    2013-08-15

    The computed radiography (CR) has become the most used device for image acquisition, since its introduction in the 80s. The detection and early diagnosis, obtained through CR examinations, are important for the successful treatment of diseases of the hand. However, the norms used for optimization of these images are based on international protocols. Therefore, it is necessary to determine letters of radiographic techniques for CR system, which provides a safe medical diagnosis, with doses as low as reasonably achievable. The objective of this work is to develop an extremity homogeneous phantom to be used in the calibration process of radiographic techniques. In the construction process of the simulator, it has been developed a tissues' algorithm quantifier using Matlab®. In this process the average thickness was quantified from bone and soft tissues in the region of the hand of an anthropomorphic simulator as well as the simulators' material thickness corresponding (aluminum and Lucite) using technique of mask application and removal Gaussian histogram corresponding to tissues of interest. The homogeneous phantom was used to calibrate the x-ray beam. The techniques were implemented in a calibrated hand anthropomorphic phantom. The images were evaluated by specialists in radiology by the method of VGA. Skin entrance surface doses were estimated (SED) corresponding to each technique obtained with their respective tube charge. The thicknesses of simulators materials that constitute the homogeneous phantom determined in this study were 19.01 mm of acrylic and 0.81 mm of aluminum. A better picture quality with doses as low as reasonably achievable decreased dose and tube charge around 53.35% and 37.78% respectively, compared normally used by radiology diagnostic routine clinical of HCFMB-UNESP. (author)

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

    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.

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

    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.

  13. Proton radiography and proton computed tomography based on time-resolved dose measurements

    Testa, Mauro; Verburg, Joost M.; Rose, Mark; Min, Chul Hee; Tang, Shikui; Hassane Bentefour, El; Paganetti, Harald; Lu, Hsiao-Ming

    2013-11-01

    We present a proof of principle study of proton radiography and proton computed tomography (pCT) based on time-resolved dose measurements. We used a prototype, two-dimensional, diode-array detector capable of fast dose rate measurements, to acquire proton radiographic images expressed directly in water equivalent path length (WEPL). The technique is based on the time dependence of the dose distribution delivered by a proton beam traversing a range modulator wheel in passive scattering proton therapy systems. The dose rate produced in the medium by such a system is periodic and has a unique pattern in time at each point along the beam path and thus encodes the WEPL. By measuring the time dose pattern at the point of interest, the WEPL to this point can be decoded. If one measures the time-dose patterns at points on a plane behind the patient for a beam with sufficient energy to penetrate the patient, the obtained 2D distribution of the WEPL forms an image. The technique requires only a 2D dosimeter array and it uses only the clinical beam for a fraction of second with negligible dose to patient. We first evaluated the accuracy of the technique in determining the WEPL for static phantoms aiming at beam range verification of the brain fields of medulloblastoma patients. Accurate beam ranges for these fields can significantly reduce the dose to the cranial skin of the patient and thus the risk of permanent alopecia. Second, we investigated the potential features of the technique for real-time imaging of a moving phantom. Real-time tumor tracking by proton radiography could provide more accurate validations of tumor motion models due to the more sensitive dependence of proton beam on tissue density compared to x-rays. Our radiographic technique is rapid (˜100 ms) and simultaneous over the whole field, it can image mobile tumors without the problem of interplay effect inherently challenging for methods based on pencil beams. Third, we present the reconstructed p

  14. Diagnostic Value of Cone-Beam Computed Tomography and Periapical Radiography In Detection of Vertical Root Fracture

    Ezzodini Ardakani, Fatemeh; Razavi, Seyed Hossein; Tabrizizadeh, Mehdi

    2015-01-01

    Introduction: Vertical root fracture (VRF) is the longitudinal fracture of the root in endodontically treated teeth. Considering the limitations of two-dimensional radiographic images in detection of VRF and introduction of cone-beam computed tomography (CBCT), this study was designed to find the sensitivity, specificity and accuracy of CBCT and periapical (PA) radiography in detection of VRFs. Methods and Materials: This was a cross-sectional in vitro study on 80 extracted human single canal teeth including 40 maxillary and 40 mandibular teeth. After standardized endodontic treatment of the roots, VRF was induced in half of the teeth in each group, and other half were left without fracture. Teeth were inserted in dry maxillary and mandibular alveoli. PA radiographs and CBCT images were taken from the specimens. Data were analyzed with SPSS software. The McNemar test was used to evaluate the sensitivity, specificity and accuracy of images, and kappa coefficient was used to assess the degree of agreement between the observers. The level of significance was set at 0.05. Results: Sensitivity and specificity values of CBCT were 97.5% and 95%, respectively. However, for PA radiography the sensitivity and specificity were 67.5% and 92.5%, in order of appearance. Accuracy of CBCT (96.25%) and PA radiography (80%) in both jaws were significantly different (P=0.022). Two methods were not significantly different when testing specificity (P=0.298). Conclusion: This study showed that the sensitivity and accuracy of CBCT in detection of vertical root fracture are higher than periapical radiography. CBCT can be recommended to be used in detection of vertical root fractures. PMID:25834597

  15. Chest radiography and thoracic computed tomography findings in children who have family members with active pulmonary tuberculosis

    Uzum, Kazim; Karahan, Okkes I.; Dogan, Sukru; Coskun, Abdulhakim E-mail: coskuna@erciyes.edu.tr; Topcu, Faik

    2003-12-01

    Objective: The chest radiography and TCT findings in children who had contacted with adult family members with active pulmonary tuberculosis were compared. The contributions of thoracic computed tomography to the diagnosis of tuberculosis were investigated. Methods and material: The children who were 0-16 years old (n=173) and children of families with an adult member which was diagnosed as pulmonary tuberculosis were evaluated. The children were considered in two groups based on the absence (n=125) or presence (n=48) of complaints and/or ambiguous symptoms such as lack of appetite, mild cough, sweating, history of lung infection, low body weight and those with suspicious chest radiography findings (12 cases) were included in this study. Asymptomatic patients (n=125) did not undergo TCT. Patients who had positive PPD skin tests only received isoniazid. If the TCT demonstrated enlarged lymph nodes or parenchymal lesions, minimally active pulmonary tuberculosis was diagnosed and antituberculous treatment was given. Results and discussions: TCT revealed lymph node enlargement or parenchymal lesions in 39 children (81.2%). Of the 12 children whose CXRs revealed suspicious lymph node enlargement and/or infiltration, five had normal findings in TCT whereas the initial findings were confirmed in the remaining seven. These data suggest that there is a correlation between the presence of ambiguous symptoms in exposed children and TCT findings; chest radiography and TCT findings do not yield parallel findings. All the patients who received anti-TB treatment were resolved in the control examinations. Conclusion: In this study there is a correlation between presence of ambiguous symptoms and TCT findings, but the chest radiography and TCT findings do not yield harmony in exposed children with ambiguous symptoms (suspicious tuberculosis cases). These observations should be considered in children with symptoms similar to those of exposed children, but with no definite history of

  16. Free software for performing physical analysis of systems for digital radiography and mammography

    Donini, Bruno; Lanconelli, Nico, E-mail: nico.lanconelli@unibo.it [Alma Mater Studiorum, Department of Physics and Astronomy, University of Bologna, Bologna 40127 (Italy); Rivetti, Stefano [Fisica Medica, Ospedale di Sassuolo S.p.A., Sassuolo 41049 (Italy); Bertolini, Marco [Medical Physics Unit, Azienda Ospedaliera ASMN, Istituto di Ricovero e Cura a Carattere Scientifico, Reggio Emilia 42123 (Italy)

    2014-05-15

    Purpose: In this paper, the authors present a free software for assisting users in achieving the physical characterization of x-ray digital systems and image quality checks. Methods: The program was developed as a plugin of a well-known public-domain suite ImageJ. The software can assist users in calculating various physical parameters such as the response curve (also termed signal transfer property), modulation transfer function (MTF), noise power spectra (NPS), and detective quantum efficiency (DQE). It also includes the computation of some image quality checks: defective pixel analysis, uniformity, dark analysis, and lag. Results: The software was made available in 2009 and has been used during the last couple of years by many users who gave us valuable feedback for improving its usability. It was tested for achieving the physical characterization of several clinical systems for digital radiography and mammography. Various published papers made use of the outcomes of the plugin. Conclusions: This software is potentially beneficial to a variety of users: physicists working in hospitals, staff working in radiological departments, such as medical physicists, physicians, engineers. The plugin, together with a brief user manual, are freely available and can be found online ( http://www.medphys.it/downloads.htm ). With our plugin users can estimate all three most important parameters used for physical characterization (MTF, NPS, and also DQE). The plugin can run on any operating system equipped with ImageJ suite. The authors validated the software by comparing MTF and NPS curves on a common set of images with those obtained with other dedicated programs, achieving a very good agreement.

  17. Finding-specific display presets for computed radiography soft-copy reading.

    Andriole, K P; Gould, R G; Webb, W R

    1999-05-01

    Much work has been done to optimize the display of cross-sectional modality imaging examinations for soft-copy reading (i.e., window/level tissue presets, and format presentations such as tile and stack modes, four-on-one, nine-on-one, etc). Less attention has been paid to the display of digital forms of the conventional projection x-ray. The purpose of this study is to assess the utility of providing presets for computed radiography (CR) soft-copy display, based not on the window/level settings, but on processing applied to the image optimized for visualization of specific findings, pathologies, etc (i.e., pneumothorax, tumor, tube location). It is felt that digital display of CR images based on finding-specific processing presets has the potential to: speed reading of digital projection x-ray examinations on soft copy; improve diagnostic efficacy; standardize display across examination type, clinical scenario, important key findings, and significant negatives; facilitate image comparison; and improve confidence in and acceptance of soft-copy reading. Clinical chest images are acquired using an Agfa-Gevaert (Mortsel, Belgium) ADC 70 CR scanner and Fuji (Stamford, CT) 9000 and AC2 CR scanners. Those demonstrating pertinent findings are transferred over the clinical picture archiving and communications system (PACS) network to a research image processing station (Agfa PS5000), where the optimal image-processing settings per finding, pathologic category, etc, are developed in conjunction with a thoracic radiologist, by manipulating the multiscale image contrast amplification (Agfa MUSICA) algorithm parameters. Soft-copy display of images processed with finding-specific settings are compared with the standard default image presentation for 50 cases of each category. Comparison is scored using a 5-point scale with the positive scale denoting the standard presentation is preferred over the finding-specific processing, the negative scale denoting the finding

  18. NPWE model observer as a validated alternative for contrast detail analysis of digital detectors in general radiography

    Van Peteghem, N.; Bosmans, H.; Marshall, N. W.

    2016-11-01

    To propose and validate a non-prewhitening with eye filter (NPWE) model observer as an alternative means of quantifying and specifying imaging performance for general radiography detectors, in a comparative study with contrast detail analysis and detective quantum efficiency (DQE). Five different x-ray detectors were assessed, covering a range of detector technologies including powder computed radiography (CR), needle CR, and three indirect conversion flat panel digital radiography detectors (DR). For each detector, threshold contrast detail (c-d) detectability was measured using the Leeds TO20 test object. A tube voltage of 70 kV and 1 mm Cu added filtration was used and five target detector air kerma (DAK) levels were set, ranging from 0.625 µGy to 10 µGy. Three c-d images were acquired at the same DAK levels and these were scored by two observers. Presampling modulation transfer function (MTF) was measured using an edge method while contrast was measured with a 2 mm Al square of dimension 10  ×  10 mm. The normalized noise power spectrum (NNPS) was calculated at the target DAK values of the c-d images. The MTF, NNPS and contrast data were then used to calculate a detectability index (d‧) with the NPWE model and compared to the human observer c-d results. The standard quantitative means of evaluating detector performance i.e. DQE, was then calculated for each detector. A linear correlation was found between the logarithm of threshold contrast and the logarithm of d’ for all detectors, as DAK was increased. Furthermore, the absolute value of d‧ tracked threshold contrast between the five detectors, enabling the use of detectability to quantify image quality rather than the intrinsically subjective threshold contrast scored by human observers from c-d test object images. At 2.5 µGy target DAK, d’ followed the differences in DQE between the five detectors. The NPWE detectability index can be used an alternative parameter for the

  19. Three-dimensional biplanar radiography as a new means of accessing femoral version: a comparitive study of EOS three-dimensional radiography versus computed tomography

    Pomerantz, M.L. [University of California San Diego School of Medicine, Orthopaedic Surgery Department, San Diego, CA (United States); Glaser, Diana [Aurora Spine, Carlsbad, CA (United States); Doan, Josh [Orthopedic Biomechanics Research Center, San Diego, CA (United States); Kumar, Sita [University of California, San Diego, CA (United States); Edmonds, Eric W. [University of California San Diego School of Medicine, Orthopaedic Surgery Department, San Diego, CA (United States); Rady Children' s Hospital San Diego, Division of Orthopedic Surgery, San Diego, CA (United States)

    2014-10-17

    To validate femoral version measurements made from biplanar radiography (BR), three-dimensional (3D) reconstructions (EOS imaging, France) were made in differing rotational positions against the gold standard of computed tomography (CT). Two cadaveric femurs were scanned with CT and BR in five different femoral versions creating ten total phantoms. The native version was modified by rotating through a mid-diaphyseal hinge twice into increasing anteversion and twice into increased retroversion. For each biplanar scan, the phantom itself was rotated -10, -5, 0, +5 and +10 . Three-dimensional CT reconstructions were designated the true value for femoral version. Two independent observers measured the femoral version on CT axial slices and BR 3D reconstructions twice. The mean error (upper bound of the 95 % confidence interval), inter- and intraobserver reliability, and the error compared to the true version were determined for both imaging techniques. Interobserver intraclass correlation for CT axial images ranged from 0.981 to 0.991, and the intraobserver intraclass correlation ranged from 0.994 to 0.996. For the BR 3D reconstructions these values ranged from 0.983 to 0.998 and 0.982 to 0.998, respectively. For the CT measurements the upper bound of error from the true value was 5.4-7.5 , whereas for BR 3D reconstructions it was 4.0-10.1 . There was no statistical difference in the mean error from the true values for any of the measurements done with axial CT or BR 3D reconstructions. BR 3D reconstructions accurately and reliably provide clinical data on femoral version compared to CT even with rotation of the patient of up to 10 from neutral. (orig.)

  20. Neutron radiography and X-ray computed tomography for quantifying weathering and water uptake processes inside porous limestone used as building material

    Dewanckele, J., E-mail: jan.dewanckele@gmail.com [Department of Geology and Soil Science—UGCT, Ghent University, Krijgslaan 281 S8, B-9000 Ghent (Belgium); De Kock, T. [Department of Geology and Soil Science—UGCT, Ghent University, Krijgslaan 281 S8, B-9000 Ghent (Belgium); Fronteau, G. [University of Reims Champagne-Ardenne (URCA), GEGENAA, EA3795 Reims (France); Derluyn, H. [Chair of Building Physics, ETH Zurich, HIL E 47.2, Wolfgang-Pauli-Strasse 15, 8093 Zürich Hönggerberg (Switzerland); Vontobel, P. [Spallation Neutron Source Division, Paul Scherrer Institut (PSI), Villigen (Switzerland); Dierick, M.; Van Hoorebeke, L. [Department of Physics and Astronomy—UGCT, Ghent University, Proeftuinstraat 86, B-9000 Ghent (Belgium); Jacobs, P.; Cnudde, V. [Department of Geology and Soil Science—UGCT, Ghent University, Krijgslaan 281 S8, B-9000 Ghent (Belgium)

    2014-02-15

    Euville and Savonnières limestones were weathered by acid test and this resulted in the formation of a gypsum crust. In order to characterize the crystallization pattern and the evolution of the pore structure below the crust, a combination of high resolution X-ray computed tomography and SEM–EDS was used. A time lapse sequence of the changing pore structure in both stones was obtained and afterwards quantified by using image analysis. The difference in weathering of both stones by the same process could be explained by the underlying microstructure and texture. Because water and moisture play a crucial role in the weathering processes, water uptake in weathered and non-weathered samples was characterized based on neutron radiography. In this way the water uptake was both visualized and quantified in function of the height of the sample and in function of time. In general, the formation of a gypsum crust on limestone slows down the initial water uptake in the materials. - Highlights: • Time lapse sequence in 3D of changing pore structures inside limestone • A combination of X-ray CT, SEM and neutron radiography was used. • Quantification of water content in function of time, height and weathering • Characterization of weathering processes due to gypsum crystallization.

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

    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.)

  2. PyRAT (python radiography analysis tool): overview

    Armstrong, Jerawan C [Los Alamos National Laboratory; Temple, Brian A [Los Alamos National Laboratory; Buescher, Kevin L [Los Alamos National Laboratory

    2011-01-14

    PyRAT was developed as a quantitative tool for robustly characterizing objects from radiographs to solve problems such as the hybrid nonlinear inverse problem. The optimization software library that was used is the nonsmooth optimization by MADS algorithm (NOMAD). Some of PyRAT's features are: (1) hybrid nonlinear inverse problem with calculated x-ray spectrum and detector response; (2) optimization based inversion approach with goal of identifying unknown object configurations - MVO problem; (3) using functionalities of Python libraries for radiographic image processing and analysis; (4) using the Tikhonov regularization method of linear inverse problem to recover partial information of object configurations; (5) using a priori knowledge of problem solutions to define feasible region and discrete neighbor for the MVO problem - initial data analysis + material library {yields} a priori knowledge; and (6) using the NOMAD (C++ version) software in the object.

  3. Screening Performance Characteristic of Ultrasonography and Radiography in Detection of Pleural Effusion; a Meta-Analysis

    Mahmoud Yousefifard

    2016-01-01

    Full Text Available Introduction: The role of ultrasonography in detection of pleural effusion has long been a subject of interest but controversial results have been reported. Accordingly, this study aims to conduct a systematic review of the available literature on diagnostic value of ultrasonography and radiography in detection of pleural effusion through a meta-analytic approach. Methods: An extended search was done in databases of Medline, EMBASE, ISI Web of Knowledge, Scopus, Cochrane Library, and ProQuest. Two reviewers independently extracted the data and assessed the quality of the articles. Meta-analysis was performed using a mixed-effects binary regression model. Finally, subgroup analysis was carried out in order to find the sources of heterogeneity between the included studies. Results: 12 studies were included in this meta-analysis (1554 subjects, 58.6% male. Pooled sensitivity of ultrasonography in detection of pleural effusion was 0.94 (95% CI: 0.88-0.97; I2= 84.23, p<0.001 and its pooled specificity was calculated to be 0.98 (95% CI: 0.92-1.0; I2= 88.65, p<0.001, while sensitivity and specificity of chest radiography were 0.51 (95% CI: 0.33-0.68; I2= 91.76, p<0.001 and 0.91 (95% CI: 0.68-0.98; I2= 92.86, p<0.001, respectively. Sensitivity of ultrasonography was found to be higher when the procedure was carried out by an intensivist or a radiologist using 5-10 MHz transducers. Conclusion: Chest ultrasonography, as a screening tool, has a higher diagnostic accuracy in identification of plural effusion compared to radiography. The sensitivity of this imaging modality was found to be higher when performed by a radiologist or an intensivist and using 5-10MHz probes.

  4. Comparing intraoral radiography and computed tomography for detecting radiographic signs of periodontitis and endodontic disease in dogs: an agreement study.

    Robert David Campbell

    2016-08-01

    Full Text Available Objective: To determine whether computed tomography and intraoral radiography are interchangeable for detecting signs of periodontitis and endodontic disease in dogs. Materials and Methods: An agreement study was performed using 40 dogs that previously underwent intraoral radiography and computed tomography during the same anesthetic episode. Images of each tooth were examined by two blinded observers for signs of periodontitis and/or endodontic disease. Agreement between imaging modalities and between observers was assessed using the Kappa statistic.Results: Agreement between modalities for detecting periodontitis in the maxillae ranged from poor to very good (κ 0.07-1.00 with 16/20 (80% of the teeth having a score of moderate or better (κ ≥ 0.41. Agreement between modalities for detecting signs consistent with periodontitis in the mandibles ranged from poor to very good (κ 0.01-1.00 with 10/22 (45% of the teeth having a score of good or better (κ ≥0.61; 50% of the disagreement was present in the incisors. Agreement between modalities for detecting signs consistent with endodontic disease in the whole mouth ranged from fair to very good (κ 0.21-1.00 with 30/42 (71% of the teeth having a score of moderate or better (κ ≥0.41. Agreement between observers evaluating IOR ranged from poor to very good (κ 0.05-1 for detecting signs consistent with periodontitis and from fair to very good (κ 0.36-1 for detecting signs consistent with endodontic disease, in the whole mouth. Agreement between observers evaluating CT ranged from fair to very good (κ 0.35-1 for detecting signs consistent with periodontitis and from fair to very good (κ 0.36-1 for detecting signs consistent with endodontic disease, in the whole mouth Conclusions: Performing both computed tomography and intraoral radiography may be unnecessary to detect signs consistent with periodontitis and endodontic disease in dogs based on the amount of agreement between modalities and

  5. Accuracy of Digital Radiography and Cone Beam Computed Tomography on Periapical Radiolucency Detection in Endodontically Treated Teeth

    Tadas Venskutonis

    2014-07-01

    Full Text Available Objectives: The aim of the present study was to compare the accuracy of intraoral digital periapical radiography and cone beam computed tomography in the detection of periapical radiolucencies in endodontically treated teeth. Material and Methods: Radiographic images (cone beam computed tomography [CBCT] scans and digital periapical radiography [PR] images from 60 patients, achieved from September 2008 to July 2013, were retrieved from databases of the Department of Oral Diseases, Lithuanian University of Health Sciences. Twenty patients met inclusion criteria and were selected for further evaluation. Results: In 20 patients (42.4 [SD 12.1] years, 65% men and 35% women a total of 35 endodontically treated teeth (1.75 [SD 0.91]; 27 in maxilla and 8 in mandible were evaluated. Overall, it was observed a statistical significant difference between the number of periapical lesions observed in the CBCT (n = 42 and radiographic (n = 24 examinations (P < 0.05. In molar teeth, CBCT identify a significantly higher amount of periapical lesions than with the radiographic method (P < 0.05. There were significant differences between CBCT and PR in the mean number of lesions identified per tooth (1.2 vs 0.66, P = 0.03, number of teeth with lesions (0.71 vs 0.46, P = 0.03 and number of lesions identified per canal (0.57 vs 0.33, P = 0.005. Considering CBCT as “gold standard” in lesion detection with the sensitivity, specificity and accuracy considering as score 1, then the same parameters of PR were 0.57, 1 and 0.76 respectively. Conclusions: Within the limitations of the present study, it can be concluded that cone beam computed tomography scans were more accurate compared to digital periapical radiographs for detecting periapical radiolucencies in endodontically treated teeth. The difference was more pronounced in molar teeth.

  6. Detection of bone erosions in rheumatoid arthritis wrist joints with magnetic resonance imaging, computed tomography and radiography

    Døhn, Uffe Møller; Ejbjerg, Bo J; Hasselquist, Maria

    2008-01-01

    BACKGROUND: The objectives of the present study were, with multidetector computed tomography (CT) as the reference method, to determine the performance of magnetic resonance imaging (MRI) and radiography for the detection of bone erosions in rheumatoid arthritis wrist bones, and to test whether...... on the same day. CT was performed on a Philips Mx8000IDT unit (voxel size 0.4 mm x 0.4 mm x 1 mm) and MRI was performed on a Philips Panorama 0.6T unit (voxel size 0.4 mm x 0.4 mm x 0.4 mm). Images were evaluated separately for erosions in all wrist bones and were scored according to the principles.......90 (both P persons' total erosion volume and total score (all P

  7. Performance evaluation of three computed radiography systems using methods recommended in American Association of Physicists in Medicine Report 93

    Wilbroad Muhogora

    2011-01-01

    Full Text Available The performances of three clinical computed radiography (CR systems, (Agfa CR 75 (with CRMD 4.0 image plates, Kodak CR 850 (with Kodak GP plates and Kodak CR 850A (with Kodak GP plates were evaluated using six tests recommended in American Association of Physicists in Medicine Report 93. The results indicated variable performances with majority being within acceptable limits. The variations were mainly attributed to differences in detector formulations, plate readers′ characteristics, and aging effects. The differences of the mean low contrast scores between the imaging systems for three observers were statistically significant for Agfa and Kodak CR 850A (P=0.009 and for Kodak CR systems (P=0.006 probably because of the differences in ages. However, the differences were not statistically significant between Agfa and Kodak CR 850 (P=0.284 suggesting similar perceived image quality. The study demonstrates the need to implement quality control program regularly.

  8. Automatic exposure control calibration and optimisation for abdomen, pelvis and lumbar spine imaging with an Agfa computed radiography system

    Moore, C. S.; Wood, T. J.; Avery, G.; Balcam, S.; Needler, L.; Joshi, H.; Saunderson, J. R.; Beavis, A. W.

    2016-11-01

    The use of three physical image quality metrics, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and mean effective noise equivalent quanta (eNEQm) have recently been examined by our group for their appropriateness in the calibration of an automatic exposure control (AEC) device for chest radiography with an Agfa computed radiography (CR) imaging system. This study uses the same methodology but investigates AEC calibration for abdomen, pelvis and spine CR imaging. AEC calibration curves were derived using a simple uniform phantom (equivalent to 20 cm water) to ensure each metric was held constant across the tube voltage range. Each curve was assessed for its clinical appropriateness by generating computer simulated abdomen, pelvis and spine images (created from real patient CT datasets) with appropriate detector air kermas for each tube voltage, and grading these against reference images which were reconstructed at detector air kermas correct for the constant detector dose indicator (DDI) curve currently programmed into the AEC device. All simulated images contained clinically realistic projected anatomy and were scored by experienced image evaluators. Constant DDI and CNR curves did not provide optimized performance but constant eNEQm and SNR did, with the latter being the preferred calibration metric given that it is easier to measure in practice. This result was consistent with the previous investigation for chest imaging with AEC devices. Medical physicists may therefore use a simple and easily accessible uniform water equivalent phantom to measure the SNR image quality metric described here when calibrating AEC devices for abdomen, pelvis and spine imaging with Agfa CR systems, in the confidence that clinical image quality will be sufficient for the required clinical task. However, to ensure appropriate levels of detector air kerma the advice of expert image evaluators must be sought.

  9. Diagnostic Value of Panoramic Radiography, Cone Beam Computed Tomography (CBCT and Clinical Measurement in Determining Bone Dimensions

    Amirreza Babaloo

    2015-07-01

    Full Text Available Introduction: Calculation of the bone dimensions is of great importance for implant treatment. Several radiographic modalities have been used for this purpose. This study compared the accuracy of mesiodistal measurements of bone using panoramic radiography, cone beam computed tomography (CBCT, and the clinical methods. Methods: In this descriptive cross-sectional study, panoramic and CBCT images were obtained from 100 implant patients. Mesiodistal bone dimensions (distance between tooth CEJ in the mesial of edentulous region and CEJ of the tooth in distal of edentulous region were calculated using a scaled ruler on the orthopantomograms and the system software in the CBCT images. During the implant insertions, a mucoperiosteal flap was raised and clinical dimensions of the bone were measured by a periodontal probe and bone gauge. The differences of bone height and thickness measurements between gold standard and CBCT or panoramic modalities were analyzed using Student’s t- test. Results: The mean bone height was 10.64±1.55, 11.44±1.51, and 10.68±1.6 mm in the clinical, panoramic and CBCT modalities, respectively. Statistically significant difference was noted between the clinical and panoramic techniques (P0.05. During the bone height calculations, 79%, 62% and 78% of the images were ranked in the normal range using CBCT, panoramic and gold standard measurements, respectively. The mean areas under the ROC curve were 0.92 and 0.83 in CBCT and panoramic techniques, respectively. Conclusion: Accuracy of the CBCT images was higher than panoramic technique in measuring the bone dimensions and this technique can be confidently used to calculate the bone dimensions for the implant surgeries.   Keywords: Partially edentulous jaw; panoramic radiography; cone-beam computed tomography; bone dimensions

  10. Identification of microorganisms for the analysis of images obtained by neutron radiography

    Lopes, J.D.R.; Crispim, V.R. E-mail: verginia@lmn.con.ufrj.br; Lage, C

    2001-06-01

    The main difficulty in identifying infectious microorganisms is the time required to obtain a reliable result, a minimum of 72 h. We propose a reduction to about 5 h through the technique of neutron radiography. Samples containing the bacillus Escherichia coli and the cocci Staphylococcus epidermidis were incubated with B{sup 10}, layered on SSNTD (CR-39) surface and irradiated in the J-9 channel from the Argonauta Reactor (IEN/CNEN) with a flux of thermal neutrons at a rate of 2.2x10{sup 5} n/cm{sup 2} s. Images were observed in an optical microscope after exposure of the plates to chemical development of the latent alpha-tracks. Analysis of the images revealed morphological differences between the species, conferring the technique the perspective to use in microbial diagnosis.

  11. Organ-specific dosimetry in spinal radiography: an analysis of genetic and somatic effects

    Fickel, T.E.

    1988-02-01

    Radiation doses absorbed by the uterus, ovary, testicle and active bone marrow are computed for cervical, thoracic, lumbar, full spine and chest series performed under typical office conditions. Assuming a nonthreshold, linear relationship between dose and radiogenic effect, the computed tissue-specific doses are used to estimate the probability that each X-ray series might enhance the statistical probability of occurrence of an adult leukemia fatality of the irradiated patient; a childhood leukemia, mental retardation or cancer fatality as a result of fetal irradiation; or a variety of sex cell chromosomal aberrations in irradiated patients. It is concluded that the greatest hazard to active bone marrow, the uterus and the gonads is posed by lumbar and full spine radiography and that the need to adequately justify such exposure is mandatory; furthermore, in these series, irradiation of the ovary is 10 times as great as that of the testicle. Lumbar radiographic examinations can be made significantly safer by the elimination of the lumbosacral spot view.

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

    Boyd D. Christensen

    2009-05-01

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

  13. Changes of the hip joints associated with chronic subluxation and dislocation: CT and plain radiography analysis

    Yang, Ik; Ryu, Kyung Nam; Lee, Sun Wha; Choi, Woo Suk; Lee, Eil Seong [Kyung Hee University Hospital, Seoul (Korea, Republic of)

    1993-05-15

    Secondary osteoarthritis of the hip joint is a common disease and is frequently followed by chronic subluxation and dislocation. Twenty four cases of the secondary osteoarthritis associated with chronic subluxation and dislocation of the hip joints were evaluated with plain radiography and computed tomography. We retrospectively analyzed 1) the osteoarthritis and calcification of the acetabular labrum, 2) the thickness of the quadrilateral plate of the ilium, and 3) anteroposterior diameter of the acetabulum. The changes of the hip joints in subluxation (n=14) revealed ossification of the acetabular labrum in 12 cases (86%), thickening of the quadrilateral plate of the ilium in 11 cases (78%) but anteroposterior diameter of the acetabulum was not changed. The changes of the hip joints in dislocation (n=10) revealed no evidence of the ossification of the acetabular labrum, thickening of the quadrilateral plate of the ilium in 10 cases (100%) and decreased anteroposterior diameter of the acetabulum. We conclude that CT findings of subluxation and dislocation of the hip joints can be helpful in the evaluation of the secondary osteoarthritis of the hip joints.

  14. X-Ray Digital Radiography and Computed Tomography Characterization of Targets

    Sain, J D; Brown, W D; Chinn, D J; Martz Jr., H E; Morales, K E; Schneberk, D J; Updike, E O

    2008-04-16

    The summary of this report is: (1) The Xradia Micro XCT and LLNL CCAT x-ray systems are used to nondestructively characterize a variety of materials, assemblies, and reference standard components; (2) The digital radiograph (DR) and computed tomography (CT) image data may be used for metrology, quality control, and defect detection; and (3) The ability to detect and characterize imperfections leads to improvements in the manufacturing processes for assemblies.

  15. Comparison of panoramic radiography and cone-beam computed tomography for qualitative and quantitative measurements regarding localization of permanent impacted maxillary canines

    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.

  16. Computational movement analysis

    Laube, Patrick

    2014-01-01

    This SpringerBrief discusses the characteristics of spatiotemporal movement data, including uncertainty and scale. It investigates three core aspects of Computational Movement Analysis: Conceptual modeling of movement and movement spaces, spatiotemporal analysis methods aiming at a better understanding of movement processes (with a focus on data mining for movement patterns), and using decentralized spatial computing methods in movement analysis. The author presents Computational Movement Analysis as an interdisciplinary umbrella for analyzing movement processes with methods from a range of fi

  17. Painful spondylolysis or spondylolisthesis studied by radiography and single-photon emission computed tomography

    Collier, B.D.; Johnson, R.P.; Carrera, G.F.; Meyer, G.A.; Schwab, J.P.; Flatley, T.J.; Isitman, A.T.; Hellman, R.S.; Zielonka, J.S.; Knobel, J.

    1985-01-01

    Planar bone scintigraphy (PBS) and single-photon emission computed tomography (SPECT) were compared in 19 adults with radiographic evidence of spondylolysis and/or spondylolisthesis. SPECT was more sensitive than PBS when used to identify symptomatic patients and sites of painful defects in the pars interarticularis. In addition, SPECT allowed more accurate localization than PBS. In 6 patients, spondylolysis or spondylolisthesis was unrealted to low back pain, and SPECT images of the posterior neural arch were normal. The authors conclude that when spondylolysis or spondylolisthesis is the cause of low back pain, pars defects are frequently heralded by increased scintigraphic activity which is best detected and localized by SPECT.

  18. MEASUREMENT OF ROOT LENGTH DENSITY IN INTACT SAMPLES USING X-RADIOGRAPHY AND IMAGE ANALYSIS

    Alain Pierret

    2011-05-01

    Full Text Available Measurement of root system attributes is of critical importance to understand and model plant growth. Root length density, the length of roots per unit volume of soil, is one of the important parameters required to understand plant performance. Measuring techniques currently in use to assess this parameter, such as for example core washing, are notoriously imprecise and labour-intensive. Roots and soil being inextricably linked, it is virtually impossible to separate them without loosing a significant amount of the root sample to be measured. This noticeably compromises the accuracy of washing techniques. For this reason, non-invasive measurement approaches are highly desirable. Here, a method based on the combination of X-radiography and image analysis is proposed as a new alternative for the measurement of root length density from intact samples. The successive steps of the method, from sampling to image acquisition are briefly described. A specific measurement algorithm, designed to account for the complex spatial arrangement of the roots within the samples is then presented and discussed in detail.

  19. Imaging in early rheumatoid arthritis: roles of magnetic resonance imaging, ultrasonography, conventional radiography and computed tomography

    Østergaard, Mikkel; Ejbjerg, Bo; Szkudlarek, Marcin

    2005-01-01

    Efficient methods for diagnosis, monitoring and prognostication are essential in early rheumatoid arthritis (RA). While conventional X-rays only visualize the late signs of preceding disease activity, there is evidence for magnetic resonance imaging (MRI) and ultrasonography being highly sensitive...... for early inflammatory and destructive changes in RA joints, and for MRI findings being sensitive to change and of predictive value for future progressive X-ray damage. Reviewing the data on X-ray, computed tomography, MRI and ultrasonography in RA, this paper discusses current and future roles...... of these imaging modalities in the management of early RA. The main focus is on recent advances in MRI and ultrasonography. Suggestions on clinical use and research priorities are provided...

  20. The teaching of computer programming and digital image processing in radiography.

    Allan, G L; Zylinski, J

    1998-06-01

    The increased use of digital processing techniques in Medical Radiations imaging modalities, along with the rapid advance in information technology has resulted in a significant change in the delivery of radiographic teaching programs. This paper details a methodology used to concurrently educate radiographers in both computer programming and image processing. The students learn to program in visual basic applications (VBA), and the programming skills are contextualised by requiring the students to write a digital subtraction angiography (DSA) package. Program code generation and image presentation interface is undertaken by the spreadsheet Microsoft Excel. The user-friendly nature of this common interface enables all students to readily begin program creation. The teaching of programming and image processing skills by this method may be readily generalised to other vocational fields where digital image manipulation is a professional requirement.

  1. Long-term evaluation of apical root resorption after orthodontic treatment using periapical radiography and cone beam computed tomography

    Jairo Curado de Freitas

    2013-08-01

    Full Text Available OBJECTIVE: To evaluate the frequency of Apical Root Resorption (ARR after orthodontic treatment at 52-288 months using periapical radiography (PR and cone beam computed tomography (CBCT. METHODS: Radiographic images obtained from 58 patients, before (T1 and after orthodontic treatment (T2, and following 52-288 months of treatment were analyzed by three members of the Brazilian Board of Orthodontics. Apical structures were evaluated by PR images (T2 and T3, using Levander and Malmgren scores. The presence of ARR on CBCT images were detected only at T3. The Kolmogorov-Smirnov test was used for statistical analyses, and the level of significance was set at 5%. Kappa statistics determined interobserver agreement. RESULTS: The more frequent ARR were with scores 1 in T2 (51.6% and T3 (53.1%, when evaluated by PR (p > 0.05. When compared the frequencies of ARR in T3 among PR and CBCT images, the differences were significant for maxillary and mandibular pre-molar groups, and for mandibular molar group (p > 0.05. The teeth with highest frequency of ARR presence using CBCT images were maxillary lateral incisors (94.5% and mandibular central incisors (87.7%, while the premolars showed the lowest frequency. The CBCT images showed that the teeth involved in orthodontic treatment with extraction present higher ARR frequency (p < 0.05. CONCLUSION: PR showed more frequency of ARR in posterior teeth groups when compared with CBCT images. ARR did not change in long-term post treatment.

  2. Radiography, computed tomography and magnetic resonance imaging at 0.5 Tesla of mechanically induced osteoarthritis in rabbit knees

    Torelli, S.R. [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina Veterinaria e Zootecnia. Programa de Pos-graduacao em Medicina Veterinaria; Rahal, R.S. [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina Veterinaria e Zootecnia. Dept. de Cirurgia e Anestesiologia Veterinaria]. E-mail: sheilacr@fmvz.unesp.br; Volpi, R.S. [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina. Dept. de Cirurgia e Ortopedia; Yamashita, S. [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina. Dept. de Doencas Tropicais e Diagnostico por Imagens; Mamprim, M.J. [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina Veterinaria e Zootecnia. Dept. de Reproducao Animal e Radiologia; Crocci, A.J. [UNESP, Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Bioestatistica

    2004-04-01

    In the present experimental study we assessed induced osteoarthritis data in rabbits, compared three diagnostic methods, i.e., radiography (XR), computed tomography (CT) and magnetic resonance imaging (MRI), and correlated the imaging findings with those obtained by macroscopic evaluation. Ten young female rabbits of the Norfolk breed were used. Seven rabbits had the right knee immobilized in extension for a period of 12 weeks (immobilized group), and three others did not have a limb immobilized and were maintained under the same conditions (control group). Alterations observed by XR, CT and MRI after the period of immobilization were osteophytes, osteochondral lesions, increase and decrease of joint space, all of them present both in the immobilized and non-immobilized contralateral limbs. However, a significantly higher score was obtained for the immobilized limbs (XT: P = 0.016, CT: P 0.031, MRI: P = 0.0156). All imaging methods were able to detect osteoarthritis changes after the 12 weeks of immobilization. Macroscopic evaluation identified increased thickening of joint capsule, proliferative and connective tissue in the femoropatellar joint, and irregularities of articular cartilage, especially in immobilized knees. The differences among XR, CT and MRI were not statistically significant for the immobilized knees. However, MRI using a 0.5 Tesla scanner was statistically different from CT and XR for the non-immobilized contralateral knees. We conclude that the three methods detected osteoarthritis lesions in rabbit knees, but MRI was less sensitive than XR and CT in detecting lesions compatible with initial osteoarthritis. Since none of the techniques revealed all the lesions, it is important to use all methods to establish an accurate diagnosis. (author)

  3. Radiography, computed tomography and magnetic resonance imaging at 0.5 Tesla of mechanically inducedosteoarthritis in rabbit knees

    Torelli S.R.

    2004-01-01

    Full Text Available In the present experimental study we assessed induced osteoarthritis data in rabbits, compared three diagnostic methods, i.e., radiography (XR, computed tomography (CT and magnetic resonance imaging (MRI, and correlated the imaging findings with those obtained by macroscopic evaluation. Ten young female rabbits of the Norfolk breed were used. Seven rabbits had the right knee immobilized in extension for a period of 12 weeks (immobilized group, and three others did not have a limb immobilized and were maintained under the same conditions (control group. Alterations observed by XR, CT and MRI after the period of immobilization were osteophytes, osteochondral lesions, increase and decrease of joint space, all of them present both in the immobilized and non-immobilized contralateral limbs. However, a significantly higher score was obtained for the immobilized limbs (XT: P = 0.016, CT: P = 0.031, MRI: P = 0.0156. All imaging methods were able to detect osteoarthritis changes after the 12 weeks of immobilization. Macroscopic evaluation identified increased thickening of joint capsule, proliferative and connective tissue in the femoropatellar joint, and irregularities of articular cartilage, especially in immobilized knees. The differences among XR, CT and MRI were not statistically significant for the immobilized knees. However, MRI using a 0.5 Tesla scanner was statistically different from CT and XR for the non-immobilized contralateral knees. We conclude that the three methods detected osteoarthritis lesions in rabbit knees, but MRI was less sensitive than XR and CT in detecting lesions compatible with initial osteoarthritis. Since none of the techniques revealed all the lesions, it is important to use all methods to establish an accurate diagnosis.

  4. Application of off-line image processing for optimization in chest computed radiography using a low cost system.

    Muhogora, Wilbroad E; Msaki, Peter; Padovani, Renato

    2015-03-08

     The objective of this study was to improve the visibility of anatomical details by applying off-line postimage processing in chest computed radiography (CR). Four spatial domain-based external image processing techniques were developed by using MATLAB software version 7.0.0.19920 (R14) and image processing tools. The developed techniques were implemented to sample images and their visual appearances confirmed by two consultant radiologists to be clinically adequate. The techniques were then applied to 200 chest clinical images and randomized with other 100 images previously processed online. These 300 images were presented to three experienced radiologists for image quality assessment using standard quality criteria. The mean and ranges of the average scores for three radiologists were characterized for each of the developed technique and imaging system. The Mann-Whitney U-test was used to test the difference of details visibility between the images processed using each of the developed techniques and the corresponding images processed using default algorithms. The results show that the visibility of anatomical features improved significantly (0.005 ≤ p ≤ 0.02) with combinations of intensity values adjustment and/or spatial linear filtering techniques for images acquired using 60 ≤ kVp ≤ 70. However, there was no improvement for images acquired using 102 ≤ kVp ≤ 107 (0.127 ≤ p ≤ 0.48). In conclusion, the use of external image processing for optimization can be effective in chest CR, but should be implemented in consultations with the radiologists.

  5. Text analysis and computers

    1995-01-01

    Content: Erhard Mergenthaler: Computer-assisted content analysis (3-32); Udo Kelle: Computer-aided qualitative data analysis: an overview (33-63); Christian Mair: Machine-readable text corpora and the linguistic description of danguages (64-75); Jürgen Krause: Principles of content analysis for information retrieval systems (76-99); Conference Abstracts (100-131).

  6. Accuracy of chest radiography versus chest computed tomography in hemodynamically stable patients with blunt chest trauma

    Mojtaba Chardoli; Toktam Hasan-Ghaliaee; Hesam Akbari; Vafa Rahimi-Movaghar

    2013-01-01

    Objective:Thoracic injuries are responsible for 25% of deaths of blunt traumas.Chest X-ray (CXR) is the first diagnostic method in patients with blunt trauma.The aim of this study was to detect the accuracy of CXR versus chest computed tomograpgy (CT) in hemodynamically stable patients with blunt chest trauma.Methods:Study was conducted at the emergency department of S ina Hospital from March 2011 to March 2012.Hemodynamically stable patients with at least 16 years of age who had blunt chest trauma were included.All patients underwent the same diagnostic protocol which consisted of physical examination,CXR and CT scan respectively.Results:Two hundreds patients (84% male and 16% female) were included with a mean age of(37.9±13.7) years.Rib fracture was the most common finding of CXR (12.5%) and CT scan (25.5%).The sensitivity of CXR for hemothorax,thoracolumbar vertebra fractures and rib fractures were 20%,49% and 49%,respectively.Pneumothorax,foreign body,emphysema,pulmonary contusion,liver hematoma and sternum fracture were not diagnosed with CXR alone.Conclusion:Applying CT scan as the first-line diagnostic modality in hemodynamically stable patients with blunt chest trauma can detect pathologies which may change management and outcome.

  7. High-resolution computed tomography in silicosis: correlation with chest radiography and pulmonary function tests

    Lopes, Agnaldo Jose [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Pedro Ernesto Univ. Hospital. Dept. of Respiratory Function]. E-mail: phel.lop@uol.com.br; Mogami, Roberto; Capone, Domenico; Jansen, Jose Manoel [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). School of Medical Sciences; Tessarollo, Bernardo [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Dept. of Radiology and Diagnostic Image; Melo, Pedro Lopes de [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. of Biology

    2008-05-15

    Objective: To correlate tomographic findings with pulmonary function findings, as well as to compare chest X-ray findings with high-resolution computed tomography (HRCT) findings, in patients with silicosis. Methods: A cross-sectional study was conducted in 44 non-smoking patients without a history of tuberculosis. Chest X-ray findings were classified according to the International Labour Organization recommendations. Using a semiquantitative system, the following HRCT findings were measured: the full extent of pulmonary involvement; parenchymal opacities; and emphysema. Spirometry and forced oscillation were performed. Pulmonary volumes were evaluated using the helium dilution method, and diffusing capacity of the lung for carbon monoxide was assessed. Results: Of the 44 patients studied, 41 were male. The mean age was 48.4 years. There were 4 patients who were classified as category 0 based on X-ray findings and as category 1 based on HRCT findings. Using HRCT scans, we identified progressive massive fibrosis in 33 patients, compared with only 23 patients when X-rays were used. Opacity score was found to correlate most closely with airflow, DLCO and compliance. Emphysema score correlated inversely with volume, DLCO and airflow. In this sample of patients presenting a predominance of large opacities (75% of the individuals), the deterioration of pulmonary function was associated with the extent of structural changes. Conclusions: In the early detection of silicosis and the identification of progressive massive fibrosis, HRCT scans are superior to X-rays. (author)

  8. High energy x-ray radiography and computed tomography of bridge pins

    Green, R E; Logan, C M; Martz, H E; Updike, E; Waters, A M

    1999-05-01

    Bridge pins were used in the hanger assemblies for some multi-span steel bridges built prior to the 1980's, and are sometimes considered fracture critical elements of a bridge. During a test on a bridge conducted by the Federal Highway Administration (FHWA), ultrasonic field inspection results indicated that at least two pins contained cracks. Several pins were removed and selected for further examination. This provided an excellent opportunity to learn more about these pins and the application of x-ray systems at Lawrence Livermore National Laboratory (LLNL), as well as to learn more about the application of different detectors recently obtained by LLNL. Digital radiographs and computed tomography (CT) were used to characterize the bridge pins, using a LINAC x-ray source with a 9-MV bremsstrahlung spectrum. We will describe the performance of two different digital radiographic detectors. One is a detector system frequently used at LLNL consisting of a scintillator glass optically coupled to a CCD camera. The other detector is a new amorphous silicon detector recently acquired by LLNL.

  9. Working Length Determination Using Cone-Beam Computed Tomography, Periapical Radiography and Electronic Apex Locator in Teeth with Apical Periodontitis: A Clinical Study

    de Morais, André Luiz Gomide; de Alencar, Ana Helena Gonçalves; Estrela, Cyntia Rodrigues de Araújo; Decurcio, Daniel Almeida; Estrela, Carlos

    2016-01-01

    Introduction: The purpose of this clinical study was to compare the accuracy of working length (WL) determination using cone-beam computed tomography (CBCT), conventional periapical radiographies and electronic apex locator. Methods and Materials: This study was conducted during root canal treatment of 19 patients with a total of 30 single-rooted teeth diagnosed with apical periodontitis. After taking the initial parallel periapical radiographies, the initial file was advanced into the canal until the WL was detected by the apex locator. Subsequently, the WL was measured and WL radiographies were taken with the file set in the canal. Afterwards, CBCT images were acquired. These three measurements were tabulated and compared and the data were analyzed using the Friedman test. The level of significance was set at 0.05. Results: The mean values for WL determination by electronic apex locator, periapical radiograph and CBCT images were 22.25, 22.43 and 22.65, respectively which was not statistically significant (P>0.05). Conclusion: Working length determination using CBCT images was precise when compared to radiographic method and electronic apex locator. PMID:27471524

  10. Characterization of a new generation of computed radiography system based on line scanning and phosphor needles

    Dragusin, Octavian; Rogge, Frank; Pauwels, Herman; Marchal, Guy; Bosmans, Hilde

    2006-03-01

    A new generation CR system that is based on phosphor needles and that uses a digitizer with line scan technology was compared to a clinically used CR system. Purely technical and more clinically related tests were run on both systems. This included the calculation of the DQE, signal-to-noise and contrast to noise ratios from Aluminum inserts, contrast detail analysis with the CDRAD phantom and the use of anthropomorphic phantoms (wrist, chest and skull) with scoring by a radiologist. X-ray exposures with various dose levels and 50kV, 70kV and 125kV were acquired. For detector doses above 0.8 μGy, all noise related measurements showed the superiority of the new technology. The MTF confirmed the improvement in sharpness: between 1 and 3 lp/mm increases ranged from 20 to 50%. Further work should be devoted to the determination of the required dose levels in the plate for the different radiological applications.

  11. Efficacy of plain radiography and computer tomography in localizing the site of pelvic arterial bleeding in trauma patients

    Dormagen, Johann B. (Dept. of Radiology, Oslo Univ. Hospital, Ullevaal, Oslo (Norway)), e-mail: johannd@medisin.uio.no; Toetterman, Anna (Dept. of Orthopedic Surgery, Uppsala Univ. Hospital, Uppsala (Sweden)); Roeise, Olav (Div. of Neuroscience and Musculoskeletal Medicine, Oslo Univ. Hospital, Ullevaal, Oslo (Norway)); Sandvik, Leiv (Center for Clinical Research, Oslo Univ. Hospital, Ullevaal, Oslo (Norway)); Kloew, Nils-E. (Dept. of Cardiovascular Radiology, Oslo Univ. Hospital - Ullevaal, Oslo (Norway))

    2010-01-15

    Background: Immediate angiography is warranted in pelvic trauma patients with suspected arterial injury (AI) in order to stop ongoing bleeding. Prior to angiography, plain pelvic radiography (PPR) and abdominopelvic computer tomography (CT) are performed to identify fracture and hematoma sites. Purpose: To investigate if PPR and CT can identify the location of AI in trauma patients undergoing angiography. Material and Methods: 95 patients with pelvic fractures on PPR (29 women, 66 men), at a mean age of 44 (9-92) years, underwent pelvic angiography for suspected AI. Fifty-six of them underwent CT additionally. Right and left anterior and posterior fractures on PPR were registered, and fracture displacement was recorded for each quadrant. Arterial blush on CT was registered, and the size of the hematoma in each region was measured in cm2. AIs were registered for anterior and posterior segments of both internal iliac arteries. Presence of fractures, arterial blush, and hematomas were correlated with AI. Results: Presence of fracture in the corresponding skeletal segment on PPR showed sensitivity and specificity of 0.86 and 0.58 posteriorly, and 0.87 and 0.44 anteriorly. The area under the curve (AUC) was 0.77 and 0.69, respectively. Fracture displacement on PPR >0.9 cm posteriorly and >1.9 cm anteriorly revealed specificity of 0.84. Sensitivities of arterial blush and hematoma on CT were 0.38 and 0.82 posteriorly, and 0.24 and 0.82 anteriorly. The specificities were 0.96 and 0.58 posteriorly, and 0.79 and 0.53 anteriorly, respectively. For hematomas, the AUC was 0.79 posteriorly and 0.75 anteriorly. Size of hematoma >22 cm2 posteriorly and >29 cm2 anteriorly revealed specificity of 0.85 and 0.86, respectively. Conclusion: CT findings of arterial blush and hematoma predicted site of arterial bleeding on pelvic angiography. Also, PPR predicted the site of bleeding using location of fracture and size of displacement. In the hemodynamically unstable patient, PPR may

  12. Morphology of the pelvis and hind limb of the red panda (Ailurus fulgens) evidenced by gross osteology, radiography and computed tomography.

    Makungu, M; du Plessis, W M; Groenewald, H B; Barrows, M; Koeppel, K N

    2015-12-01

    The red panda (Ailurus fulgens) is a quadrupedal arboreal animal primarily distributed in the Himalayas and southern China. It is a species commonly kept in zoological collections. This study was carried out to describe the morphology of the pelvis and hind limb of the red panda evidenced by gross osteology, radiography and computed tomography as a reference for clinical use and identification of skeletons. Radiography of the pelvis and right hind limb was performed in nine and seven animals, respectively. Radiographic findings were correlated with bone specimens from three adult animals. Computed tomography of the torso and hind limb was performed in one animal. The pelvic bone had a wide ventromedial surface of the ilium. The trochlea of the femur was wide and shallow. The patella was similar to that seen in feline species. The medial fabella was not seen radiographically in any animal. The cochlea grooves of the tibia were shallow with a poorly defined intermediate ridge. The trochlea of the talus was shallow and presented with an almost flattened medial ridge. The tarsal sesamoid bone was always present. The lateral process of the base of the fifth metatarsal (MT) bone was directed laterally. The MT bones were widely spaced. The morphology of the pelvis and hind limb of the red panda indicated flexibility of the pelvis and hind limb joints as an adaptation to an arboreal quadrupedal lifestyle.

  13. Computed tomography scout views vs. conventional radiography in body-packers – Delineation of body-packs and radiation dose in a porcine model

    Ziegeler, Edvard, E-mail: edvard.ziegeler@campus.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Grimm, Jochen M., E-mail: jochen.grimm@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Wirth, Stefan, E-mail: tefan.wirth@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Uhl, Michael, E-mail: michael.uhl@polizei.bayern.de [Bavarian State Criminal Police Office, Maillingerstrasse 15, 80636 Munich (Germany); Reiser, Maximilian F., E-mail: Maximilian.Reiser@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany); Scherr, Michael K., E-mail: Michael.Scherr@med.lmu.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Nussbaumstraße 20, 80336 Munich (Germany)

    2012-12-15

    Objective: To compare abdominal computed tomography (CT) scout views with conventional radiography regarding radiation dose and delineation of drug packages in a porcine body-packer model. Materials and methods: Nine samples of illicit drugs packed in ovoid plastic containers were consecutively placed in the rectum of a 121.5 kg pig cadaver. Antero-posterior and lateral scout views were obtained at 120 kVp and 80 mA, 150 mA and 200 mA, respectively, using a 64-row MDCT. Scout views were compared with conventional abdominal antero-posterior radiographs (77 kV and 106 ± 13 mAs). Visibility of three body pack characteristics (wrapping, content, shape) was rated independently by two radiologists and summarized to a delineation score ranging from 0 to 9 with a score ≥6 representing sufficient delineation. Mean delineation scores were calculated for each conventional radiography and single plane scout view separately and for a combined rating of antero-posterior and lateral scout views. Results: Even the lowest single plane scout view delineation score (5.3 ± 2.0 for 80 mA lateral; 0.4 mSv; sensitivity = 44%) was significantly higher than for conventional radiographs (3.1 ± 2.5, p < 0.001; 2.4 ± 0.3 mSv; sensitivity = 11%). Combined reading of antero-posterior and lateral scout views 80 mA yielded sufficient delineation (6.2 ± 1.4; 0.8 mSv; sensitivity = 56%). Conclusions: All CT scout views showed significantly better delineation ratings and sensitivity than conventional radiographs. Scout views in two planes at 80 mA provided a sufficient level of delineation and a sensitivity five times higher than conventional radiography at less than one third of the radiation dose. In case of diagnostic insecurity, CT can be performed without additional logistical effort.

  14. Computational Music Analysis

    methodological issues, harmonic and pitch-class set analysis, form and voice-separation, grammars and hierarchical reduction, motivic analysis and pattern discovery and, finally, classification and the discovery of distinctive patterns. As a detailed and up-to-date picture of current research in computational...

  15. Cholesteatoma: computed tomography and radiography in a dog; Colesteatoma: tomografia computadorizada e radiografia em cao com otite cronica

    Belotta, Alexandra Frey; Babicsak, Viviam Rocco; Mamprim, Maria Jaqueline; Vulcano, Luiz Carlos, E-mail: a_fbelotta@yahoo.com.br [Universidade Estadual Paulista Julio de Mesquita Filho (FMVZ/UNESP), Botucatu, SP (Brazil). Faculdade de Medicina Veterinaria e Zootecnia . Dept. de Reproducao Animal e Radiologia Veterinaria; Arruda, Vanesa Kutz de; Amorim, Rogerio Martins [Universidade Estadual Paulista Julio de Mesquita Filho (FMVZ/UNESP), Botucatu, SP (Brazil). Faculdade de Medicina Veterinaria e Zootecnia. Dept. de Clinica Veterinaria

    2012-07-01

    Cholesteatoma, a rare and/or misdiagnosed disease, results of a serious complication in dogs with chronic otitis. This article describes a case of a dachshund sent to the veterinary hospital presenting signs of cognitive dysfunction associated to peripheral neuropathy of the facial nerve on the right side. At radiography, an enlargement and thickness of the contours associated with loss of anatomical definition of the right tympanic bulla compared to the left was seen. At tomography, this enlargement and thickness were seen with better definition, besides the fulfilling by hyperdense calcified content, bullae osteolysis and temporal bone sclerosis at the same side. (author)

  16. Cross-sectional void fraction distribution measurements in a vertical annulus two-phase flow by high speed X-ray computed tomography and real-time neutron radiography techniques

    Harvel, G.D. [McMaster Univ., Ontario (Canada)]|[Combustion and Heat Transfer Lab., Takasago (Japan); Hori, K.; Kawanishi, K. [Combustion and Heat Transfer Lab., Takasago (Japan)] [and others

    1995-09-01

    A Real-Time Neutron Radiography (RTNR) system and a high speed X-ray Computed tomography (X-CT) system are compared for measurement of two-phase flow. Each system is used to determine the flow regime, and the void fraction distribution in a vertical annulus flow channel. A standard optical video system is also used to observe the flow regime. The annulus flow channel is operated as a bubble column and measurements obtained for gas flow rates from 0.0 to 30.01/min. The flow regimes observed by all three measurement systems through image analysis shows that the two-dimensional void fraction distribution can be obtained. The X-CT system is shown to have a superior temporal resolution capable of resolving the void fraction distribution in an (r,{theta}) plane in 33.0 ms. Void fraction distribution for bubbly flow and slug flow is determined.

  17. Industrial radiographies

    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

  18. Application of neutron radiography and tomography for analysis of root morphology of growing ginseng

    Kim, Hyun Ho; Sung, Bong Jae; Park, Jong Yoon [Geumsan Agricultural Development and Technology Center, Geumsan (Korea, Republic of); Sim, Cheul Muu; Kim, Young Jin; Lee, Seung Wook [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2005-07-01

    The shape of main root of ginseng is very important for its commercial value. The morphology of main root is predominantly determined by the root-growing pattern in one year after transplantation of ginseng seedling(one years root). There are many factors affecting the root growing of young ginseng but no systematic approach has been applied to find the effects of various factors. The main reason for this was no method was sought to see the root shapes non-destructively. Neutron radiography is thought to be an appropriate NDT method for root morphology examination in ginseng and a study on using NR for the research on ginseng is being conducted. Considering that the live plants should be moved to the reactor site for their examination of four or five times per year at least, the pot growing method is indispensable. The pot should contain enough soils for growing-up of ginseng and its maximum size is limited to have good contrast in neutron radiography image of ginseng root. Thus, a preliminary radiographic study was performed to find the proper size of ginseng pot using the NR facility of HANARO. Several pots will be prepared for young ginsengs and they will be examined for about one year.

  19. Suresh K. AggarwalQuantified Analysis of a Production Diesel Injector Using X-Ray Radiography and Engine Diagnostics

    Ramirez, Anita I.

    The work presented in this thesis pursues further the understanding of fuel spray, combustion, performance, and emissions in an internal combustion engine. Various experimental techniques including x-ray radiography, injection rate measurement, and in-cylinder endoscopy are employed in this work to characterize the effects of various upstream conditions such as injection rate profile and fuel physical properties. A single non-evaporating spray from a 6-hole full-production Hydraulically Actuated Electronically Controlled Unit Injector (HEUI) nozzle is studied under engine-like ambient densities with x-ray radiography at the Advanced Photon Source (APS) of Argonne National Laboratory (ANL). Two different injection pressures were investigated and parameters such as fuel mass distribution, spray penetration, cone angle, and spray velocity were obtained. The data acquired with x-ray radiography is used for the development and validation of improved Computational Fluid Dynamic (CFD) models. Rate of injection is studied using the same HEUI in a single cylinder Caterpillar test engine. The injection rate profile is altered to have three levels of initial injection pressure rise. Combustion behavior, engine performance, and emissions information was acquired for three rate profile variations. It is found that NOx emission reduction is achieved when the SOI timing is constant at the penalty of lower power generated in the cycle. However, if CA50 is aligned amongst the three profiles, the NOx emissions and power are constant with a slight penalty in CO emissions. The influence of physical and chemical parameters of fuel is examined in a study of the heavy alcohol, phytol (C20H40O), in internal combustion engine application. Phytol is blended with diesel in 5%, 10%, and 20% by volume. Combustion behavior is similar between pure diesel and the phytol/diesel blends with small differences noted in peak cylinder pressure, ignition delay, and heat release rate in the premix burn

  20. Discussion on the artifacts of computed radiography and its solution%计算机摄影的伪影及其解决办法的探讨

    邹才盛

    2009-01-01

    Objective To discuss the productive reasons of the artifacts of computed radiography (CR)and its solution.Methods Through analysis of the characteristics of various kind of artifacts in CR system, from scanner's mechanism, the principle of work, IP board's structure, image process, operator's errors and so on the CR artifacts productive reason were discussed.Results The artifacts may been divided into: the artifacts induced by the overlap of pre and post images,the artifacts induced by the card in the TP board scanning, the artifacts induced by "the class spatial effect", the artifacts induced by the dust, the artifacts induced by injured TP,the artifacts induced by the excessive photographic condition, the artifacts induced by the disperse beam, and the artifacts induced by the external optical fiber in the scanning process.Conclusion Understood correctly the reason of the CR artifacts, can prevent the production of the artifacts as far as possible, greatly enhances the image quality of CR.%目的 探讨计算机摄影(CR)伪影的产生原因及解决办法.方法 通过分析CR系统各种伪影的特点,从扫描器的机械结构、工作原理、IP板的构造、影像处理、操作者的错误等方面阐述CR伪影的产生原因.结果 伪影大概可分为:前后次影像重叠伪影、IP板扫描中卡片引起的伪影、"流空效应"伪影、灰尘引起的伪影、IP受损引起的伪影、摄影条件过高产生的伪影、散射线引起的伪影、扫描过程中外来光线引起的伪影等方面.结论 正确认识CR伪影产生的原因,并采取相应的预防措施就能尽量防止伪影的产生,大大提高CR的影像质量.

  1. Development of a Neutron Radiography Three-Dimensional Computed Tomography System for Void Fraction Measurement of Boiling Flow in Tight Lattice Rod Bundles

    Kureta, Masatoshi

    A neutron radiography three-dimensional computed tomography (NR3DCT) system was developed to visualize the void fraction distribution of boiling flow in tight lattice heated-rod bundles. This paper chiefly reports on the data processing and the error estimation method of NR3DCT. Practical γ-ray noise reduction and image correction techniques were studied to improve the reliability of the experimental data. Using the system and a directly heated 14-rod bundle test section, the behavior of boiling flow in a tight lattice rod bundle was clearly visualized. The effect of each data processing step on the result was also discussed. By this development, the three-dimensional vapor distribution of boiling flow in a heated bundle is made clear, and void fraction databases can be provided for verification of a thermal-hydraulic simulation code.

  2. Computational Analysis of Behavior.

    Egnor, S E Roian; Branson, Kristin

    2016-07-01

    In this review, we discuss the emerging field of computational behavioral analysis-the use of modern methods from computer science and engineering to quantitatively measure animal behavior. We discuss aspects of experiment design important to both obtaining biologically relevant behavioral data and enabling the use of machine vision and learning techniques for automation. These two goals are often in conflict. Restraining or restricting the environment of the animal can simplify automatic behavior quantification, but it can also degrade the quality or alter important aspects of behavior. To enable biologists to design experiments to obtain better behavioral measurements, and computer scientists to pinpoint fruitful directions for algorithm improvement, we review known effects of artificial manipulation of the animal on behavior. We also review machine vision and learning techniques for tracking, feature extraction, automated behavior classification, and automated behavior discovery, the assumptions they make, and the types of data they work best with.

  3. Scattering influences in quantitative fission neutron radiography for the in situ analysis of hydrogen distribution in metal hydrides

    Börries, S., E-mail: stefan.boerries@hzg.de [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Max-Planck-Strasse 1, D-21502 Geesthacht (Germany); Metz, O.; Pranzas, P.K. [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Max-Planck-Strasse 1, D-21502 Geesthacht (Germany); Bücherl, T. [ZTWB Radiochemie München (RCM), Technische Universität München (TUM), Walther-Meissner-Str. 3, D-85748 Garching (Germany); Söllradl, S. [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRMII), Technische Universität München (TUM), Lichtenbergstr. 1, D-85748 Garching (Germany); Dornheim, M.; Klassen, T.; Schreyer, A. [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Max-Planck-Strasse 1, D-21502 Geesthacht (Germany)

    2015-10-11

    In situ neutron radiography allows for the time-resolved study of hydrogen distribution in metal hydrides. However, for a precise quantitative investigation of a time-dependent hydrogen content within a host material, an exact knowledge of the corresponding attenuation coefficient is necessary. Additionally, the effect of scattering has to be considered as it is known to violate Beer's law, which is used to determine the amount of hydrogen from a measured intensity distribution. Within this study, we used a metal hydride inside two different hydrogen storage tanks as host systems, consisting of steel and aluminum. The neutron beam attenuation by hydrogen was investigated in these two different setups during the hydrogen absorption process. A linear correlation to the amount of absorbed hydrogen was found, allowing for a readily quantitative investigation. Further, an analysis of scattering contributions on the measured intensity distributions was performed and is described in detail.

  4. Computed Radiography and Computed Tomography of Chest Wall Diseases%胸壁病变的计算机X线摄影和CT检查

    洪庆坚; 李惠民; 肖湘生; 王晨光; 胡爱妹

    2000-01-01

    Purpose: To analyze computed radiography (CR) and computed tomography (CT) findings of diseases of chest wall and to investigate the value of CR and CT in diagnosis of these diseases. Materials and Methods: The findings and diagnoses of 39 cases with proved (by fina needle biopsy, or surgory and/or pathology, of clinical follow up) chest wall disease were analysed retrospectively. Resulte: In 12 infective lesions, including purulent infection (4 cases) and tuberculosis (8 cases), the correct dignosis was made in 4cases by CR and in 11 cases by CT. In 16 soft tissue tumors, including lipoma (7 cases), fibrosarcoma (4 cases), hemangioma (1 case), neurofibroma (1 case), malignant fibrous histocytoma (1case), aggressive fibromatosis (1 case) and liposarcoma (1 case), the correct diagnosis was made in 3cases by CR and in 14 cases by CT. In 11 bone lesions, including fibrous dysplasia (7 cases), chondroma (2 cases), myeloma (lcase) and cosinophilic granuloma (1 case), the correct diagnosis was made in 8cases by CR and in 10 cases by CT. Conclusion: CR is useful in the dignosis of chest wall bone diseases. CT is obviously superior to CR for demonstration of all chest wall diseases espacially for soft tissue lesions. CT has definite value for the differentiation of malignant from benign tumore of chest wall, but still has certain limit.%目的:探讨胸壁病变的计算机X线摄影(CR)和CT表现及其诊断价值,提高对胸壁病变的认识。材料和方法:回顾分析经手术病理、穿刺细胞学检查或临床随访资料证实的39例CR和CT资料。结果:感染组12例中(包括化脓性感染4例,胸壁结核8例),CR准确诊断4例,CT诊断11例;软组织肿瘤组16例中(包括脂肪瘤7例,纤维肉瘤4例,血管瘤、神经纤维瘤、恶性纤维组织细胞瘤、侵袭性纤维瘤病和脂肪肉瘤各l例),CR准确诊断3例,CT诊断14例;骨肿瘤和肿瘤样病变组11例中(包括骨纤维异常增殖症7例,软骨瘤2

  5. Accuracy of Lung Ultrasonography versus Chest Radiography for the Diagnosis of Adult Community-Acquired Pneumonia: Review of the Literature and Meta-Analysis.

    Xiong Ye

    Full Text Available Lung ultrasonography (LUS is being increasingly utilized in emergency and critical settings. We performed a systematic review of the current literature to compare the accuracy of LUS and chest radiography (CR for the diagnosis of adult community-acquired pneumonia (CAP. We searched in Pub Med, EMBASE dealing with both LUS and CR for diagnosis of adult CAP, and conducted a meta-analysis to evaluate the diagnostic accuracy of LUS in comparison with CR. The diagnostic standard that the index test compared was the hospital discharge diagnosis or the result of chest computed tomography scan as a "gold standard". We calculated pooled sensitivity and specificity using the Mantel-Haenszel method and pooled diagnostic odds ratio using the DerSimonian-Laird method. Five articles met our inclusion criteria and were included in the final analysis. Using hospital discharge diagnosis as reference, LUS had a pooled sensitivity of 0.95 (0.93-0.97 and a specificity of 0.90 (0.86 to 0.94, CR had a pooled sensitivity of 0.77 (0.73 to 0.80 and a specificity of 0.91 (0.87 to 0.94. LUS and CR compared with computed tomography scan in 138 patients in total, the Z statistic of the two summary receiver operating characteristic was 3.093 (P = 0.002, the areas under the curve for LUS and CR were 0.901 and 0.590, respectively. Our study indicates that LUS can help to diagnosis adult CAP by clinicians and the accuracy was better compared with CR using chest computed tomography scan as the gold standard.

  6. Analysis of the reproducibility of the gray values and noise of a direct digital radiography system

    Marcelo Lupion POLETI

    2015-01-01

    Full Text Available The aim of this study was to evaluate the reproducibility of the gray values and noise of a direct digital radiography system (Visualix eHD for various exposure times and analyzed regions. To obtain radiographic images in a standardized manner, the digital sensor of the system and a stepwedge were positioned in a phantom at a focus-film distance of 30 cm in a dental device at 70 kV, 7 mA and 2.2 mm filtration. Ten consecutive repetitions of X-ray imaging were performed at each exposure time (0.05, 0.07, 0.09 and 0.13 s. Gray values were analyzed using ImageJ software in five regions of interest (ROIs: alveolar bone (AB, soft tissue (ST and three steps of the stepwedge (S1, S2 and S3. The results showed that both the variability of the gray values and the noise were statistically greater (p < 0.05 in the most radiolucent region (ST. Only the noise was affected by the exposure time. In conclusion, the reproducibility of the gray values and the noise of the Visualix eHD system can vary in specific areas with different radiolucency.

  7. Radiography with polarised neutrons

    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

  8. Analysis of the impact of digital tomosynthesis on the radiological investigation of patients with suspected pulmonary lesions on chest radiography

    Quaia, Emilio; Baratella, Elisa; Cernic, Stefano; Lorusso, Arianna; Casagrande, Federica; Cioffi, Vincenzo; Cova, Maria Assunta [University of Trieste (Italy), Department of Radiology, Cattinara Hospital, Trieste (Italy)

    2012-09-15

    To assess the impact of digital tomosynthesis (DTS) on the radiological investigation of patients with suspected pulmonary lesions on chest radiography (CXR). Three hundred thirty-nine patients (200 male; age, 71.19 {+-} 11.9 years) with suspected pulmonary lesion(s) on CXR underwent DTS. Two readers prospectively analysed CXR and DTS images, and recorded their diagnostic confidence: 1 or 2 = definite or probable benign lesion or pseudolesion deserving no further diagnostic workup; 3 = indeterminate; 4 or 5 = probable or definite pulmonary lesion deserving further diagnostic workup by computed tomography (CT). Imaging follow-up by CT (n = 76 patients), CXR (n = 256) or histology (n = 7) was the reference standard. DTS resolved doubtful CXR findings in 256/339 (76 %) patients, while 83/339 (24 %) patients proceeded to CT. The mean interpretation time for DTS (mean {+-} SD, 220 {+-} 40 s) was higher (P < 0.05; Wilcoxon test) than for CXR (110 {+-} 30 s), but lower than CT (600 {+-} 150 s). Mean effective dose was 0.06 mSv (range 0.03-0.1 mSv) for CXR, 0.107 mSv (range 0.094-0.12 mSv) for DTS, and 3 mSv (range 2-4 mSv) for CT. DTS avoided the need for CT in about three-quarters of patients with a slight increase in the interpretation time and effective dose compared to CXR. (orig.)

  9. A simple quality assurance test tool for the visual verification of light and radiation field congruent using electronic portal images device and computed radiography

    Njeh Christopher F

    2012-03-01

    Full Text Available Abstract Background The radiation field on most megavoltage radiation therapy units are shown by a light field projected through the collimator by a light source mounted inside the collimator. The light field is traditionally used for patient alignment. Hence it is imperative that the light field is congruent with the radiation field. Method A simple quality assurance tool has been designed for rapid and simple test of the light field and radiation field using electronic portal images device (EPID or computed radiography (CR. We tested this QA tool using Varian PortalVision and Elekta iViewGT EPID systems and Kodak CR system. Results Both the single and double exposure techniques were evaluated, with double exposure technique providing a better visualization of the light-radiation field markers. The light and radiation congruency could be detected within 1 mm. This will satisfy the American Association of Physicists in Medicine task group report number 142 recommendation of 2 mm tolerance. Conclusion The QA tool can be used with either an EPID or CR to provide a simple and rapid method to verify light and radiation field congruence.

  10. Simulation analysis and exp erimental verification of fast neutron radiography%快中子照相模拟分析与实验验证∗

    鲁昌兵; 许鹏; 鲍杰; 王朝辉; 张凯; 任杰; 刘艳芬

    2015-01-01

    Expression for the formation of the pixel value of fast neutron radiography has been derived. The contrast inequality for the photograph has been established using the derived expression;then the relationships of the image contrast with the source intensity, the exposure time, and the scattering have therefore been obtained through the acquired inequality. A simulation on the process of fast neutron radiography is carried out based on the pixel value analysis, and the spatial resolution and image contrast have also been considered. Simulation results show that the spatial resolution is better than that from experiments and the effect of image contrast is equivalent to that of the experiments. Finally, various samples, such as Pb samples, with slits, Fe samples with square holes and multiple materials-combined samples, are used to test the performance of the simulation. Results demonstrate that the simulations are in agreement with the experiments, thus providing a reference to the future experimental design and engineering application.

  11. Visualization and quantification of water movement in porous cement-based materials by real time thermal neutron radiography:Theoretical analysis and experimental study

    2010-01-01

    Water movement in porous cement-based materials is of great importance when studying their deterioration processes and durability.Many traditional methods based on mass changes,electricity or nuclear magnetic resonances are available for studying water transport in cement-based materials.In this research,an advanced technique i.e.thermal neutron radiography was utilized to achieve visualization and quantification of time dependent water movement including water penetration and moisture vapor in porous cement-based materials through theoretical analysis and experimental study.Because thermal neutrons ex-perience a strong attenuation by hydrogen,neutron radiography exhibits high sensitivity to small amounts of water.A neutron transmission analysis for quantitative evaluation of raw radiographic measurements was developed and optimized based on point scattered functions(PScF).The determinations of the real time and space dependent water penetration into uncracked and cracked mortar samples,as well as the drying process have been presented in this paper.It is illustrated that thermal neutron radiography can be a useful research tool for visualization and quantification of water movement in porous building materials.The obtained results will help us to better understand deteriorating processes of cement-based materials and to find ways to improve their durability.

  12. Imaging in rheumatoid arthritis--status and recent advances for magnetic resonance imaging, ultrasonography, computed tomography and conventional radiography

    Østergaard, Morten; Dohn, U.M.; Østergaard, Mikkel;

    2008-01-01

    , and have several documented and potential applications in RA patients. This chapter will review key aspects of the current status and recent important advances in imaging in RA, briefly discussing X-ray and computed tomography, and particularly focusing on MRI and US. Suggestions for use in clinical trials...

  13. Outcome of root canal treatment in dogs determined by periapical radiography and cone-beam computed tomography scans

    de Paula-Silva, F.W.G.; Hassan, B.; da Silva, L.A.B.; Leonardo, M.R.; Wu, M.K.

    2009-01-01

    The purpose of this study was to compare the favorable outcome of root canal treatment determined by periapical radiographs (PRs) and cone beam computed tomography (CBCT) scans. Ninety-six roots of dogs' teeth were used to form four groups (n= 24). In group 1, root canal treatments were performed in

  14. Digital chest radiography

    Debess, Jeanne Elisabeth; Vejle-Sørensen, Jens Kristian; Thomsen, Henrik;

    2015-01-01

    of clinical supervisors. Optimal collimation is determined by European and Regional Danish guidelines. The areal between current and optimal collimation is calculated. The experimental research is performed in September - October 2014 Siemens Axiom Aristos digital radiography system DR using 150 kV, 1,25 -3......Purpose: Quality improvement of basic radiography focusing 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 of age are included in the study. The clinical research is performed between September and November 2014 where 3rd year Radiography students collect data on four Danish x-ray departments using identical procedures under guidance...

  15. Analysis of bacterial contamination on surface of general radiography equipment and CT equipment in emergency room of radiology

    Hong, Dong Hee; KIm, Hyeong Gyun [Dept. of Radiological Science, Far East University, Eumseong (Korea, Republic of)

    2016-09-15

    We aim to offer basic materials about infection management through conducting bacterial contamination test about general radiography equipment and CT equipment installed in ER of three general hospitals with 100 sickbeds or more located in Gyeongsangbuk-do Province, and suggest management plan. It had been conducted from 1st December 2015 to 31st December, and objects were general radiography equipment and CT equipment of emergency room located in Gyeongsangbuk-do Province. For general radiography equipment, sources were collected from 4 places such as upper side of control box which employees use most, upper side of exposure button, whole upper side of table which is touching part of patient's skin, upper side of stand bucky's grid, and where patients put their jaws on. For CT equipment, sources were collected from 3 places such as upper side of control box which radiography room employees use most, X-ray exposure button, whole upper side of table which is touching part of patient's skin, and gantry inner. Surface contamination strain found at general radiography equipment in emergency room of radiology are Providencia stuartii(25%), Stenotrophomonas maltophilia(18%), Enterobacter cloacae(8%), Pseudomonas species(8%), Staphylococcus epidermidis(8%), Gram negative bacilli(8%), and ungrown bacteria at incubator after 48 hours of incubation (67%) which is the biggest. Most bacteria were found at upper side of stand bucky-grid and stand bucky of radiology's general radiography equipment, and most sources of CT equipment were focused at patient table, which means it is contaminated by patients who have various diseases, and patients who have strains with decreased immunity may get severe diseases. Thus infection prevention should be made through 70% alcohol disinfection at both before test and after test.

  16. In Vitro Comparison of Cone Beam Computed Tomography with Digital Periapical Radiography for Detection of Vertical Root Fracture in Posterior Teeth

    Abdinian, Mehrdad; Razavian, Hamid; Jenabi, Nastaran

    2016-01-01

    Statement of the Problem The diagnosis of vertical root fracture (VRF) is a challenging task. Purpose This in vitro study compared cone beam computed tomography (CBCT) imaging with digital periapical radiography (DPR) made by three different horizontal angels (20°mesial, 0° and 20° distal) for accurate diagnosis of VRF. Materials and Method Among 120 posterior teeth included in this study, 60 were vertically fractured. Fractured and non-fractured teeth were randomly distributed into three groups defined as group 1 with no filling in the root canal, group 2 with gutta-percha in the canal, and group 3 with the intracanal post. All samples were placed in a dry mandible and imaged with CBCT and DPR techniques. Two blind observers investigated the images. Results CBCT had higher sensitivity but lower specificity compared with DPR, except for the intracanal post group in which the sensitivity of DPR was higher; though the chi-square test showed the differences to be statistically insignificant. The sensitivity, specificity, and accuracy of CBCT and DPR were reduced in the cases that gutta-percha or post were present in the canal. Inter-observer agreement was higher for CBCT. A set of three DPRs with different horizontal angels were significantly more sensitive for VRF recognition than a single orthogonal DPR. Conclusion Based on our results, there was no significant difference between CBCT and a set of three DPRs with different angulations for VRF detection in posterior teeth. Therefore, it is suggested to consider DPRs with three different horizontal angels (20°mesial, 0° and 20° distal) for radiographic evaluation before CBCT examination. PMID:27284552

  17. In Vitro Comparison of Cone Beam Computed Tomography with Digital Periapical Radiography for Detection of Vertical Root Fracture in Posterior Teeth

    Mehrdad Abdinian

    2016-06-01

    Full Text Available Statement of the Problem: The diagnosis of vertical root fracture (VRF is a challenging task. Purpose: This in vitro study compared cone beam computed tomography (CBCT imaging with digital periapical radi-ography (DPR made by three different horizontal angels (20°mesial, 0° and 20° distal for accurate diagnosis of VRF. Materials and Method: Among 120 posterior teeth included in this study, 60 were vertically fractured. Fractured and non-fractured teeth were randomly distributed into three groups defined as group 1 with no filling in the root canal, group 2 with gutta-percha in the canal, and group 3 with the intracanal post. All samples were placed in a dry mandible and imaged with CBCT and DPR techniques. Two blind observers investigated the images. Results: CBCT had higher sensitivity but lower specificity compared with DPR, except for the intracanal post group in which the sensitivity of DPR was higher; though the chi-square test showed the differences to be statistically insignifi-cant. The sensitivity, specificity, and accuracy of CBCT and DPR were reduced in the cases that gutta-percha or post were present in the canal. Inter-observer agreement was higher for CBCT. A set of three DPRs with different horizontal angels were significantly more sensitive for VRF recognition than a single orthogonal DPR. Conclusion: Based on our results, there was no significant difference between CBCT and a set of three DPRs with dif-ferent angulations for VRF detection in posterior teeth. Therefore, it is suggested to consider DPRs with three different horizontal angels (20°mesial, 0° and 20° distal for radiographic evaluation before CBCT examination.

  18. Experimental study of the X-ray spectra optimization for computed radiography mammography systems; Investigacao experimental da otimizacao do espectro de raios X em sistemas de mamografia computadorizada

    Tomal, Alessandra, E-mail: atomal@ifi.unicamp.br [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Instituto de Fisica Gleb Wataghin; Cunha, Diego M. [Universidade Federal de Uberlandia (UFU), Uberlandia, MG (Brazil). Instituto de Fisica; Nogueira, Maria S. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Gaspar, Fabio [Vigilancia Sanitaria, Campinas, SP (Brazil); Poletti, Martin E. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Departamento de Fisica

    2013-12-15

    Digital mammography is replacing screen-film mammography due to several advantages of digital receptors. The use of Computed Radiography (CR) mammography systems has been considered an alternative to achieve digital images with a low cost. Besides, the optimization of the X-ray spectrum, characterized by the anode/filter combination and tube potential, is an important step in order to improve the image quality with the lower dose to the breast. In this work, we investigated the optimal X-ray spectra using a figure of merit for two mammography equipment: Senographe DMR (General Electric Medical Systems) and Mammomat 3000 Nova (Siemens), both using an image plate Kodak EHR-M2 (Kodak DirectView). A PMMA phantom, simulating breast with thicknesses of 5 cm, was used. The anode/filter combinations evaluated were: Mo/Mo, Mo/Rh, Rh/Rh and Rh/Al for the Senographe system, and Mo/Mo, Mo/Rh, W/Rh for the Mammomat system, for all the intervals of tube potential range from 24 to 35 kVp. Results demonstrate that the higher values of FOM were achieved with the Rh/Rh at 29 kVp and Rh/Al at 26 kVp for the Senographe system, and for the W/Rh at 28 kVp in the Mammomat one. The reduction in the dose associated with the optimum spectra was 13 and 26% for the Senographe and Mammomat systems, respectively. Finally, our results suggest that anode/filter combinations of more energetic spectra than the standard Mo/Mo combination are recommended for thicker breast, in order to reduce the breast dose levels. (author)

  19. Fully automatic and reference-marker-free image stitching method for full-spine and full-leg imaging with computed radiography

    Wang, Xiaohui; Foos, David H.; Doran, James; Rogers, Michael K.

    2004-05-01

    Full-leg and full-spine imaging with standard computed radiography (CR) systems requires several cassettes/storage phosphor screens to be placed in a staggered arrangement and exposed simultaneously to achieve an increased imaging area. A method has been developed that can automatically and accurately stitch the acquired sub-images without relying on any external reference markers. It can detect and correct the order, orientation, and overlap arrangement of the subimages for stitching. The automatic determination of the order, orientation, and overlap arrangement of the sub-images consists of (1) constructing a hypothesis list that includes all cassette/screen arrangements, (2) refining hypotheses based on a set of rules derived from imaging physics, (3) correlating each consecutive sub-image pair in each hypothesis and establishing an overall figure-of-merit, (4) selecting the hypothesis of maximum figure-of-merit. The stitching process requires the CR reader to over scan each CR screen so that the screen edges are completely visible in the acquired sub-images. The rotational displacement and vertical displacement between two consecutive sub-images are calculated by matching the orientation and location of the screen edge in the front image and its corresponding shadow in the back image. The horizontal displacement is estimated by maximizing the correlation function between the two image sections in the overlap region. Accordingly, the two images are stitched together. This process is repeated for the newly stitched composite image and the next consecutive sub-image until a full-image composite is created. The method has been evaluated in both phantom experiments and clinical studies. The standard deviation of image misregistration is below one image pixel.

  20. Digital chest radiography

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

    2015-01-01

    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...... collimations depending on side of radiograph. Results from dose reduction will be presented on the congress Conclusion: Correct positioning and collimation of digital chest radiographs can reduce the radiation dose significant to the patients and by that improve the quality of basic radiography....

  1. Comparison of Cone-Beam Computed Tomography and Periapical Radiography in Predicting Treatment Decision for Periapical Lesions: A Clinical Study

    Ashok Balasundaram

    2012-01-01

    Full Text Available Objectives. To compare the ability of endodontists to determine the size of apical pathological lesions and select the most appropriate choice of treatment based on lesions’ projected image characteristics using 2 D and 3 D images. Study Design. Twenty-four subjects were selected. Radiographic examination of symptomatic study teeth with an intraoral periapical radiograph revealed periapical lesions equal to or greater than 3 mm in the greatest diameter. Cone-beam Computed tomography (CBCT images were made of the involved teeth after the intraoral periapical radiograph confirmed the size of lesion to be equal to greater than 3 mm. Six observers (endodontists viewed both the periapical and CBCT images. Upon viewing each of the images from the two imaging modalities, observers (1 measured lesion size and (2 made decisions on treatment based on each radiograph. Chi-square test was used to look for differences in the choice of treatment among observers. Results. No significant difference was noted in the treatment plan selected by observers using the two modalities (χ2(3=.036, P>0.05. Conclusion. Lesion size and choice of treatment of periapical lesions based on CBCT radiographs do not change significantly from those made on the basis of 2 D radiographs.

  2. Analysis of muon radiography of the Toshiba nuclear critical assembly reactor

    Morris, C. L.; Bacon, Jeffery; Borozdin, Konstantin; Fabritius, J. M.; Perry, John; Ramsey, John [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Ban, Yuichiro; Izumi, Mikio; Sano, Yuji; Yoshida, Noriyuki [Toshiba Corporation, 8 Shinsugita-cho, Isogo-ku, Yokohama 235-8523 (Japan); Miyadera, Haruo [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Toshiba Corporation, 8 Shinsugita-cho, Isogo-ku, Yokohama 235-8523 (Japan); Mizokami, Shinya; Otsuka, Yasuyuki; Yamada, Daichi [Tokyo Electric Power Company, 1-1-3 Uchisaiwai-cho, Chiyoda-ku, Tokyo (Japan); Sugita, Tsukasa; Yoshioka, Kenichi [Toshiba Corporation, 4-1 Ukishima-cho, Kawasaki-ku, Kawasaki 210-0862 (Japan)

    2014-01-13

    A 1.2 × 1.2 m{sup 2} muon tracker was moved from Los Alamos to the Toshiba facility at Kawasaki, Japan, where it was used to take ∼4 weeks of data radiographing the Toshiba Critical Assembly Reactor with cosmic ray muons. In this paper, we describe the analysis procedure, show results of this experiment, and compare the results to Monte Carlo predictions. The results validate the concept of using cosmic rays to image the damaged cores of the Fukushima Daiichi reactors.

  3. Digital radiography image quality: image processing and display.

    Krupinski, Elizabeth A; Williams, Mark B; Andriole, Katherine; Strauss, Keith J; Applegate, Kimberly; Wyatt, Margaret; Bjork, Sandra; Seibert, J Anthony

    2007-06-01

    This article on digital radiography image processing and display is the second of two articles written as part of an intersociety effort to establish image quality standards for digital and computed radiography. The topic of the other paper is digital radiography image acquisition. The articles were developed collaboratively by the ACR, the American Association of Physicists in Medicine, and the Society for Imaging Informatics in Medicine. Increasingly, medical imaging and patient information are being managed using digital data during acquisition, transmission, storage, display, interpretation, and consultation. The management of data during each of these operations may have an impact on the quality of patient care. These articles describe what is known to improve image quality for digital and computed radiography and to make recommendations on optimal acquisition, processing, and display. The practice of digital radiography is a rapidly evolving technology that will require timely revision of any guidelines and standards.

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

    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. Accuracy of periapical radiography and cone-beam computed tomography scans in diagnosing apical periodontitis using histopathological findings as a gold standard

    de Paula-Silva, F.W.G.; Wu, M.K.; Leonardo, M.R.; da Silva, L.A.B.; Wesselink, P.R.

    2009-01-01

    Introduction: The aim of this study was to evaluate the accuracy of two imaging methods in diagnosing apical periodontitis (AP) using histopathological findings as a gold standard. Methods: The periapex of 83 treated or untreated roots of dogs' teeth was examined using periapical radiography (PR), c

  6. Computer analysis of railcar vibrations

    Vlaminck, R. R.

    1975-01-01

    Computer models and techniques for calculating railcar vibrations are discussed along with criteria for vehicle ride optimization. The effect on vibration of car body structural dynamics, suspension system parameters, vehicle geometry, and wheel and rail excitation are presented. Ride quality vibration data collected on the state-of-the-art car and standard light rail vehicle is compared to computer predictions. The results show that computer analysis of the vehicle can be performed for relatively low cost in short periods of time. The analysis permits optimization of the design as it progresses and minimizes the possibility of excessive vibration on production vehicles.

  7. Assessment of image quality in orthopaedic radiography with digital detectors: a visual grading analysis

    Decoster, Robin; Mol, Harrie; van den Broeck, Renaat; Smits, Dirk

    2013-03-01

    Background: The introduction of digital detectors in the radiology predicted a dose reduction. Due to the dynamic range, radiographs of sufficient quality can be produced with a lower detector air kerma (DAK). However, this reduction was not observed. Some authors indicate a creep towards higher DAK, explained by a better appreciation of the radiographs due to a higher contrast-to-noise ratio. Methodology: To investigate the relation between the DAK and the appreciation of image quality by radiologists, 172 anterior-posterior (AP) radiographs of the knee and 152 radiographs of the pelvis were collected in 19 radiology centres. A Visual Grading Analysis (VGA) with a five-point scale was used to judge the image quality of seven different anatomic structures. The mid-point of the scale (3) was equalized to diagnostic image quality. Six experienced radiologists scored both datasets, in a controlled environment, with ViewDex®. Every observer received instructions and a training dataset. Moreover, twenty radiographs were repeated to determine intra-observer variability. Results: The intra-observer variability was not significant (p>0.05) for both datasets. The knee AP obtained a VGAS score of 3.91, the pelvis AP obtained a VGAS score of 3.71. In both cases, the inter-observer correlation was high and significant. The correlation between the VGAS and the DAK (0.41μGy - 6.18μGy) was not significant in either of the cases; neither did other analysises based on technical parameters. Conclusion: The VGA revealed an image quality higher than diagnostic necessary. Based on the DAK, an overexposure is suspected. The relation between DAK and the appreciation has to be further investigated in detail.

  8. The Enhanced Workflow and Efficiency of the Wireless Local Area Network (WLAN)-Based Direct Digital Radiography (DDR) Portable Radiography.

    Ngan, Tsz-Lung; Wong, Edward Ting-Hei; Ng, Kris Lap-Shun; Jeor, Patrick Kwok-Shing; Lo, Gladys Goh

    2015-06-01

    With the implementation of the PACS in the hospital, there is an increasing demand from the clinicians for immediate access and display of radiological images. Recently, our hospital has installed the first wireless local area network (WLAN)-based direct digital radiography (DDR) portable radiography system. The DDR portable radiography system allows wireless retrieval of modality worklist and wireless transmission of portable X-ray image on the console to the Picture Archiving and Communication System (PACS), via WLAN connection of wireless fidelity (Wi-Fi). The aim of this study was to analyze the workflow and performance between the WLAN-based DDR portable radiography system and the old practice using conventional portable X-ray machine with computed radiography (CR) system. A total of 190 portable chest X-ray examinations were evaluated and timed, using the conventional portable X-ray machine with CR from March to April of 2012 and using the new DDR portable radiography system on December of 2012 (n = 97 for old system and n = 93 for DDR portable system). The time interval of image becoming available to the PACS using the WLAN-based DDR portable radiography system was significantly shorter than that of the old practice using the conventional portable X-ray machine with CR (6.8 ± 2.6 min for DDR portable system; 23 ± 10.2 min for old system; p DDR portable radiography system can enhance the workflow of portable radiography by reduction of procedural steps.

  9. An analysis of the experiences of radiography and radiotherapy students who are carers at one UK university

    Hussain, Zainab, E-mail: zay@liv.ac.u [Directorate of Medical Imaging and Radiotherapy, School of Health Sciences, University of Liverpool, Liverpool L69 3GB (United Kingdom); Pickering, Vicki, E-mail: vmoscrip@liv.ac.u [Directorate of Medical Imaging and Radiotherapy, School of Health Sciences, University of Liverpool, Liverpool L69 3GB (United Kingdom); Percy, Dave, E-mail: D.F.Percy@salford.ac.u [Operational Research and Applied Statistics, Salford Business School, University of Salford, Greater Manchester, M5 4WT (United Kingdom); Crane, Julie, E-mail: abbotj@liv.ac.u [Directorate of Nursing, School of Health Sciences, University of Liverpool, Liverpool L69 3GB (United Kingdom); Bogg, Jan, E-mail: jbogg@liv.ac.u [Population, Community and Behavioural Sciences, University of Liverpool, Liverpool L69 3GB (United Kingdom)

    2011-02-15

    Purpose: This is a mixed methods study of the experiences and attendance of radiography and radiotherapy students who are carers at one UK university, Undergraduate radiography and radiotherapy programmes are attracting increasing numbers of mature students. It is therefore likely that the number of students with carer responsibilities is also increasing. This study explores the experiences of higher education of students with caring responsibilities. The aim of the study is to identify possible strategies and practices to enhance the student experience and so to work towards compliance with the recent Equality Act 2010. Method: All students on the radiography (n = 130) and radiotherapy (n = 97) programmes were invited to complete a short questionnaire. Students who identified themselves as carers on the questionnaire were invited to participate in focus group sessions. Due to the issues raised in the focus groups by students with regard to attendance at university and clinical placement, student absence rates were also investigated for students with and without caring responsibilities. Results: 215 students completed the questionnaire. 30 of the 215 students identified themselves as carers. 18 carers agreed to take part in focus groups. Carers reported that having fees paid by the NHS was an important choice factor for higher education. Carers' main concerns were: timetabling, finances, support after exam failures, understanding from academic staff and attendance issues. Examination of absence rates demonstrated carers had significantly (p = 0.000) less absence than non-carers for radiography and no significant differences for radiotherapy (p = 0.105). Conclusion: The NHS states it must be reflective of the community it serves. Thus those responsible for delivering health professional programmes have a duty to recruit and retain a diverse student population. The introduction of the Equality Act 2010 means higher education institutions must consider the needs

  10. Diagnostic Accuracy of Ultrasonography and Radiography in Detection of Pulmonary Contusion; a Systematic Review and Meta-Analysis

    HOSSEINI, Mostafa; Ghelichkhani, Parisa; Baikpour, Masoud; Tafakhori, Abbas; Asady, Hadi; Haji Ghanbari, Mohammad Javad; Yousefifard, Mahmoud; Safari, Saeed

    2015-01-01

    Introduction: Ultrasonography is currently being used as one of the diagnostic modalities in various medical emergencies for screening of trauma patients. The diagnostic value of this modality in detection of traumatic chest injuries has been evaluated by several studies but its diagnostic accuracy in diagnosis of pulmonary contusion is a matter of discussion. Therefore, the present study aimed to determine the diagnostic accuracy of ultrasonography and radiography in detection of pulmonary c...

  11. Analysis of computer networks

    Gebali, Fayez

    2015-01-01

    This textbook presents the mathematical theory and techniques necessary for analyzing and modeling high-performance global networks, such as the Internet. The three main building blocks of high-performance networks are links, switching equipment connecting the links together, and software employed at the end nodes and intermediate switches. This book provides the basic techniques for modeling and analyzing these last two components. Topics covered include, but are not limited to: Markov chains and queuing analysis, traffic modeling, interconnection networks and switch architectures and buffering strategies.   ·         Provides techniques for modeling and analysis of network software and switching equipment; ·         Discusses design options used to build efficient switching equipment; ·         Includes many worked examples of the application of discrete-time Markov chains to communication systems; ·         Covers the mathematical theory and techniques necessary for ana...

  12. Radiography at CERN

    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...

  13. Affective Computing and Sentiment Analysis

    Ahmad, Khurshid

    2011-01-01

    This volume maps the watershed areas between two 'holy grails' of computer science: the identification and interpretation of affect -- including sentiment and mood. The expression of sentiment and mood involves the use of metaphors, especially in emotive situations. Affect computing is rooted in hermeneutics, philosophy, political science and sociology, and is now a key area of research in computer science. The 24/7 news sites and blogs facilitate the expression and shaping of opinion locally and globally. Sentiment analysis, based on text and data mining, is being used in the looking at news

  14. Muscle parameters estimation based on biplanar radiography.

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

    2016-11-01

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

  15. Real-time radiography

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

    1981-02-26

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

  16. Artifacts in digital radiography

    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.

  17. Statistical Uncertainty in Quantitative Neutron Radiography

    Piegsa, Florian M

    2016-01-01

    We demonstrate a novel procedure to calibrate neutron detection systems commonly used in standard neutron radiography. This calibration allows determining the uncertainties due to Poisson-like neutron counting statistics for each individual pixel of a radiographic image. The obtained statistical errors are necessary in order to perform correct quantitative analysis. This fast and convenient method is applied to real data measured at the cold neutron radiography facility ICON at the Paul Scherrer Institute. Moreover, from the results the effective neutron flux at the beam line is determined.

  18. Computer vision in microstructural analysis

    Srinivasan, Malur N.; Massarweh, W.; Hough, C. L.

    1992-01-01

    The following is a laboratory experiment designed to be performed by advanced-high school and beginning-college students. It is hoped that this experiment will create an interest in and further understanding of materials science. The objective of this experiment is to demonstrate that the microstructure of engineered materials is affected by the processing conditions in manufacture, and that it is possible to characterize the microstructure using image analysis with a computer. The principle of computer vision will first be introduced followed by the description of the system developed at Texas A&M University. This in turn will be followed by the description of the experiment to obtain differences in microstructure and the characterization of the microstructure using computer vision.

  19. High-resolution computed tomography versus chest radiography in the diagnosis of interstitial lung disease in systemic sclerosis; Avaliacao da tomografia de alta resolucao versus radiografia de torax na doenca intersticial pulmonar na esclerose sistemica

    Azevedo, Ana Beatriz Cordeiro de; Calderaro, Debora; Moreira, Caio [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Hospital das Clinicas. Servico de Reumatologia; Guimaraes, Silvana Mangeon Meirelles [Gerais Univ., Belo Horizonte, MG (Brazil). Hospital das Clinicas. Secao de Tomografia Computadorizada; Tavares Junior, Wilson Campos; Leao Filho, Hilton Muniz; Andrade, Diego Correa de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Hospital das Clinicas. Servico de Radiologia e Diagnostico por Imagem]. E-mail: wilsontavaresjrmd@yahho.fr; Ferreira, Cid Sergio; Vieira, Jose Nelson Mendes [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Medicina. Dept. de Radiologia

    2005-04-01

    Objective: To compare the accuracy of high-resolution computed tomography (HRCT) with chest radiography in the diagnosis of interstitial lung disease in systemic sclerosis (SSc). Materials And Methods: HRCT scans and chest radiographs in postero-anterior and lateral views were performed in 34 patients with systemic sclerosis, according to the American College of Rheumatology preliminary criteria for the diagnosis of SSc. The prevalence of radiological findings suggestive of interstitial lung disease in SSc seen on both imaging methods was compared. Results: Interstitial disease was observed on HRCT images of 31 patients (91%) and in the chest radiographs of 16 patients (47%). The most frequent findings observed on HRCT were septal lines (74%), honeycombing (56%) and parenchymal bands (26%). Chest radiographs showed reticular areas of attenuation in 11 patients (32%) and parenchymal distortion in 12% of the patients. In 18 patients (53%) with normal chest radiographs HRCT showed septal lines in 55%, ground glass in 44%, honeycombing in 38.5% and cysts in 33%. Conclusion: HRCT is more sensitive than chest radiography in the evaluation of incipient interstitial lung involvement in patients with SSc and can provide a justification for immunosuppressive therapy in patients with early disease. (author)

  20. Computational Aeroacoustic Analysis System Development

    Hadid, A.; Lin, W.; Ascoli, E.; Barson, S.; Sindir, M.

    2001-01-01

    Many industrial and commercial products operate in a dynamic flow environment and the aerodynamically generated noise has become a very important factor in the design of these products. In light of the importance in characterizing this dynamic environment, Rocketdyne has initiated a multiyear effort to develop an advanced general-purpose Computational Aeroacoustic Analysis System (CAAS) to address these issues. This system will provide a high fidelity predictive capability for aeroacoustic design and analysis. The numerical platform is able to provide high temporal and spatial accuracy that is required for aeroacoustic calculations through the development of a high order spectral element numerical algorithm. The analysis system is integrated with well-established CAE tools, such as a graphical user interface (GUI) through PATRAN, to provide cost-effective access to all of the necessary tools. These include preprocessing (geometry import, grid generation and boundary condition specification), code set up (problem specification, user parameter definition, etc.), and postprocessing. The purpose of the present paper is to assess the feasibility of such a system and to demonstrate the efficiency and accuracy of the numerical algorithm through numerical examples. Computations of vortex shedding noise were carried out in the context of a two-dimensional low Mach number turbulent flow past a square cylinder. The computational aeroacoustic approach that is used in CAAS relies on coupling a base flow solver to the acoustic solver throughout a computational cycle. The unsteady fluid motion, which is responsible for both the generation and propagation of acoustic waves, is calculated using a high order flow solver. The results of the flow field are then passed to the acoustic solver through an interpolator to map the field values into the acoustic grid. The acoustic field, which is governed by the linearized Euler equations, is then calculated using the flow results computed

  1. A survey of sub-specialty preferences of radiography students of the University of Lagos, Nigeria

    E T Namah

    2013-01-01

    Full Text Available Background: Technological advances and computing have expanded both the scope and capacity of diagnostic medical imaging (the radiography profession. This has created many diverse imaging modalities which in turn, have culminated in different sub-specialties in the profession. Objective: The aims of the study were to determine the level of awareness of imaging sub-specialties, preferred sub specialties and reasons for preferences of sub-specialties in senior level radiography students of the University of Lagos. Methods: The study was a prospective cross-sectional survey. Consents were obtained before the students were recruited for the study. Data Collection and Analysis: A questionnaire semi-structured in line with objectives of the study was used in data collection. A computer software Epi Info version 3.3 was used to analyze data while results were expressed as percentages of responses and were presented in tables and pie charts. Results : Greater than 90% showed awareness of sub-specialties in the radiography profession whereas 35% preferred ultrasonography to other sub-specialties. The least preferred sub-specialty was conventional radiography (4.3%. Remuneration (73.3% and less physical exertion (73.3% were major attractors to preferred sub-specialties whereas concerns over radiation hazard were major detractors (58.3%. Conclusion : Awareness of sub-specialties in the radiography profession was high amongst students studied. Furthermore, ultrasonography was the most preferred sub-specialty among the respondents. Remuneration was the main attractor to sub-specialties whereas fears over effects of ionizing radiation were the major detractors to some sub-specialties.

  2. Quantitative film radiography

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

    1991-02-26

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

  3. CCD digital radiography system

    Wang, Yi; Kang, Xi; Li, Yuanjing; Cheng, Jianping; Hou, Yafei; Han, Haiwei

    2009-07-01

    Amorphous silicon flat-panel detector is the mainstream used in digital radiography (DR) system. In latest years, scintillation screen coupled with CCD DR is becoming more popular in hospital. Compared with traditional amorphous silicon DR, CCD-DR has better spatial resolution and has little radiation damage. It is inexpensive and can be operated easily. In this paper, A kind of CCD based DR system is developed. We describe the construction of the system, the system performances and experiment results.

  4. Computational analysis of cerebral cortex

    Takao, Hidemasa; Abe, Osamu; Ohtomo, Kuni [University of Tokyo, Department of Radiology, Graduate School of Medicine, Tokyo (Japan)

    2010-08-15

    Magnetic resonance imaging (MRI) has been used in many in vivo anatomical studies of the brain. Computational neuroanatomy is an expanding field of research, and a number of automated, unbiased, objective techniques have been developed to characterize structural changes in the brain using structural MRI without the need for time-consuming manual measurements. Voxel-based morphometry is one of the most widely used automated techniques to examine patterns of brain changes. Cortical thickness analysis is also becoming increasingly used as a tool for the study of cortical anatomy. Both techniques can be relatively easily used with freely available software packages. MRI data quality is important in order for the processed data to be accurate. In this review, we describe MRI data acquisition and preprocessing for morphometric analysis of the brain and present a brief summary of voxel-based morphometry and cortical thickness analysis. (orig.)

  5. The Use of Esophageal Radiography in the Location of Atrial-Septal Puncture: Clinical Analysis of 486 Cases

    Wu Tongguo; Wang Lexing; Chen Siwei; Lin Ziqing; Yang Chengjun; Huang Liping

    2007-01-01

    Objectives To determine the safety and value of esophageal radiography as a means of locating transseptal puncture. Methods 486 patients who underwent transseptal puncture were randomized into two groups. An esophagus radiographic method of locating tansseptal puncture site was applied in the study group( n = 243 ) and modified-Ross locating method was used in the control group ( n = 243 ). After successful location, transseptal puncture was made. We observed the success rate and incidence complications in the 2 groups.Results Left atrium impression in the study group was clearly seen. Nonetheless in 120 cases of control group,the left atria silhouette was not clearly visualised. The success rate of locating transseptal puncture site in the study group and control group were 100% and 50.6% respectively ( P<0.001 ). The success rate of transseptal puncture in the study group and control group was 99.6% and 45.7% respectively ( P<0.001 ). There were no complications associated with puncture in the study group and pericardial tamponade occurred in 1 control patient. Conclusions The esophagus radiographic method of locating transseptal puncture site is accurate,safe and simple to perform. Transseptal puncture has a high success rate with few complications.

  6. “Drug mules” as a radiological challenge: Sensitivity and specificity in identifying internal cocaine in body packers, body pushers and body stuffers by computed tomography, plain radiography and Lodox

    Flach, Patricia M., E-mail: patricia.flach@irm.uzh.ch [Centre for Forensic Imaging and Virtopsy, Institute of Forensic Medicine, University of Bern, Buehlstrasse 20, 3012 Bern (Switzerland); Department of Neuroradiology, Inselspital Bern, University of Bern, 3010 Bern (Switzerland); Centre for Forensic Imaging and Virtopsy, Institute of Forensic Medicine, University of Zurich, Winterthurerstrasse 190/52, 8057 Zurich (Switzerland); Department of Radiology, University Hospital USZ, University of Zurich, Raemistrasse 100, 8091 Zurich (Switzerland); Ross, Steffen G. [Centre for Forensic Imaging and Virtopsy, Institute of Forensic Medicine, University of Bern, Buehlstrasse 20, 3012 Bern (Switzerland); Ampanozi, Garyfalia; Ebert, Lars [Centre for Forensic Imaging and Virtopsy, Institute of Forensic Medicine, University of Bern, Buehlstrasse 20, 3012 Bern (Switzerland); Centre for Forensic Imaging and Virtopsy, Institute of Forensic Medicine, University of Zurich, Winterthurerstrasse 190/52, 8057 Zurich (Switzerland); Germerott, Tanja; Hatch, Gary M. [Centre for Forensic Imaging and Virtopsy, Institute of Forensic Medicine, University of Bern, Buehlstrasse 20, 3012 Bern (Switzerland); Thali, Michael J. [Centre for Forensic Imaging and Virtopsy, Institute of Forensic Medicine, University of Bern, Buehlstrasse 20, 3012 Bern (Switzerland); Centre for Forensic Imaging and Virtopsy, Institute of Forensic Medicine, University of Zurich, Winterthurerstrasse 190/52, 8057 Zurich (Switzerland); Patak, Michael A. [Department of Radiology, Inselspital Bern, University of Bern, 3010 Bern (Switzerland); Department of Radiology, University Hospital USZ, University of Zurich, Raemistrasse 100, 8091 Zurich (Switzerland)

    2012-10-15

    Purpose: The purpose of our study was to retrospectively evaluate the specificity, sensitivity and accuracy of computed tomography (CT), digital radiography (DR) and low-dose linear slit digital radiography (LSDR, Lodox{sup ®}) in the detection of internal cocaine containers. Methods: Institutional review board approval was obtained. The study collectively consisted of 83 patients (76 males, 7 females, 16–45 years) suspected of having incorporated cocaine drug containers. All underwent radiological imaging; a total of 135 exams were performed: nCT = 35, nDR = 70, nLSDR = 30. An overall calculation of all “drug mules” and a specific evaluation of body packers, pushers and stuffers were performed. The gold standard was stool examination in a dedicated holding cell equipped with a drug toilet. Results: There were 54 drug mules identified in this study. CT of all drug carriers showed the highest diagnostic accuracy 97.1%, sensitivity 100% and specificity 94.1%. DR in all cases was 71.4% accurate, 58.3% sensitive and 85.3% specific. LSDR of all patients with internal cocaine was 60% accurate, 57.9% sensitive and 63.4% specific. Conclusions: CT was the most accurate test studied. Therefore, the detection of internal cocaine drug packs should be performed by CT, rather than by conventional X-ray, in order to apply the most sensitive exam in the medico-legal investigation of suspected drug carriers. Nevertheless, the higher radiation applied by CT than by DR or LSDR needs to be considered. Future studies should include evaluation of low dose CT protocols in order to address germane issues and to reduce dosage.

  7. A Petaflops Era Computing Analysis

    Preston, Frank S.

    1998-01-01

    This report covers a study of the potential for petaflops (1O(exp 15) floating point operations per second) computing. This study was performed within the year 1996 and should be considered as the first step in an on-going effort. 'Me analysis concludes that a petaflop system is technically feasible but not feasible with today's state-of-the-art. Since the computer arena is now a commodity business, most experts expect that a petaflops system will evolve from current technology in an evolutionary fashion. To meet the price expectations of users waiting for petaflop performance, great improvements in lowering component costs will be required. Lower power consumption is also a must. The present rate of progress in improved performance places the date of introduction of petaflop systems at about 2010. Several years before that date, it is projected that the resolution limit of chips will reach the now known resolution limit. Aside from the economic problems and constraints, software is identified as the major problem. The tone of this initial study is more pessimistic than most of the Super-published material available on petaflop systems. Workers in the field are expected to generate more data which could serve to provide a basis for a more informed projection. This report includes an annotated bibliography.

  8. Scatter in cargo radiography.

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

    2011-03-01

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

  9. Proton radiography for clinical applications

    Talamonti, C., E-mail: cinzia.talamonti@unifi.i [Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Azienda Ospedaliero-Universitaria Careggi, v.le Morgagni 85, I-50134 Firenze (Italy); Reggioli, V. [Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); Bruzzi, M. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Dipartimento di Energetica, Universita degli Studi di Firenze, via S. Marta 3, I-50139 Firenze (Italy); Bucciolini, M. [Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Azienda Ospedaliero-Universitaria Careggi, v.le Morgagni 85, I-50134 Firenze (Italy); Civinini, C. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Marrazzo, L. [Azienda Ospedaliero-Universitaria Careggi, v.le Morgagni 85, I-50134 Firenze (Italy); Menichelli, D. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Finland) (Italy); Dipartimento di Energetica, Universita degli Studi di Firenze, via S. Marta 3, I-50139 Firenze (Italy); Pallotta, S. [Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Azienda Ospedaliero-Universitaria Careggi, v.le Morgagni 85, I-50134 Firenze (Italy); Randazzo, N. [INFN, sezione di Catania, via S. Sofia 64, I-95123 Catania (Italy); Sipala, V. [INFN, sezione di Catania, via S. Sofia 64, I-95123 Catania (Italy); Dipartimento di Fisica, Universita degli Studi di Catania, via S. Sofia 64, I-95123 Catania (Italy)

    2010-01-11

    Proton imaging is not yet applied as a clinical routine, although its advantages have been demonstrated. In the context of quality assurance in proton therapy, proton images can be used to verify the correct positioning of the patient and to control the range of protons. Proton computed tomography (pCT) is a 3D imaging method appropriate for planning and verification of proton radiation treatments, because it allows evaluating the distributions of proton stopping power within the tissues and can be directly utilized when the patient is in the actual treatment position. The aim of the PRoton IMAging experiment, supported by INFN, and the PRIN 2006 project, supported by MIUR, is to realize a proton computed radiography (pCR) prototype for reconstruction of proton images from a single projection in order to validate the technique with pre-clinical studies and, eventually, to conceive the configuration of a complete pCT system. A preliminary experiment performed at the 250 MeV proton synchrotron of Loma Linda University Medical Center (LLUMC) allowed acquisition of experimental data before the completion of PRIMA project's prototype. In this paper, the results of the LLUMC experiment are reported and the reconstruction of proton images of two phantoms is discussed.

  10. Personal Computer Transport Analysis Program

    DiStefano, Frank, III; Wobick, Craig; Chapman, Kirt; McCloud, Peter

    2012-01-01

    The Personal Computer Transport Analysis Program (PCTAP) is C++ software used for analysis of thermal fluid systems. The program predicts thermal fluid system and component transients. The output consists of temperatures, flow rates, pressures, delta pressures, tank quantities, and gas quantities in the air, along with air scrubbing component performance. PCTAP s solution process assumes that the tubes in the system are well insulated so that only the heat transfer between fluid and tube wall and between adjacent tubes is modeled. The system described in the model file is broken down into its individual components; i.e., tubes, cold plates, heat exchangers, etc. A solution vector is built from the components and a flow is then simulated with fluid being transferred from one component to the next. The solution vector of components in the model file is built at the initiation of the run. This solution vector is simply a list of components in the order of their inlet dependency on other components. The component parameters are updated in the order in which they appear in the list at every time step. Once the solution vectors have been determined, PCTAP cycles through the components in the solution vector, executing their outlet function for each time-step increment.

  11. To Screen or not to Screen: Low Dose Computed Tomography in Comparison to Chest Radiography or Usual Care in Reducing Morbidity and Mortality from Lung Cancer

    Kamdar, Jay; Moats, Austin; Nguyen, Brenda

    2016-01-01

    Lung cancer has the highest mortality rate of all cancers. This paper seeks to address the question: Can the mortality of lung cancer be decreased by screening with low-dose computerized tomography (LDCT) in higher risk patients compared to chest X-rays (CXR) or regular patient care? Currently, CXR screening is recommended for certain high-risk patients. Several recent trials have examined the effectiveness of LDCT versus chest radiography or usual care as a control. These trials include National Lung Screening Trial (NLST), Detection And screening of early lung cancer with Novel imaging TEchnology (DANTE), Lung Screening Study (LSS), Depiscan, Italian Lung (ITALUNG), and Dutch-Belgian Randomized Lung Cancer Screening Trial (Dutch acronym: NELSON study). NLST, the largest trial (n=53, 454), demonstrated a decrease in mortality from lung cancer in the LDCT group (RRR=20%, P=0.004). LSS demonstrated a greater sensitivity in detecting both early stage and any stage of lung cancer in comparison to traditional CXR. Although the DANTE trial yielded data consistent with findings in LSS, it also showed that via LDCT screening a greater proportion of patients were placed under unnecessary surgical procedures. The Depiscan trial yielded a high nodule detection rate at the cost of a high false-positive rate compared to CXR screening. The ITALUNG and NELSON trials demonstrated the early detection capabilities of LDCT for lung cancers compared to usual care without surveillance imaging. False-positive findings with unnecessary workup, intervention, and radiation exposure remain significant concerns for routine LDCT screening. However, current data suggests LDCT may provide a highly sensitive and specific means for detecting lung cancers and reducing mortality. PMID:27375974

  12. Evaluation of knee-joint cartilage and menisci ten years after isolated and combined ruptures of the medial collateral ligament. Investigation by weight-bearing radiography, MR imaging and analysis of proteoglycan fragments in the joint fluid

    Lundberg, M. [Univ. Hospital, Linkoeping (Sweden). Dept. of Orthopaedics and Sports Medicine (Sweden); Thuomas, K.Aa. [Univ. Hospital, Linkoeping (Sweden). Dept. of Diagnostic Radiology; Messner, K. [Univ. Hospital, Linkoeping (Sweden). Dept. of Orthopaedics and Sports Medicine (Sweden)

    1997-01-01

    Purpose: To compare radiography, MR imaging, and chemical analysis in posttraumatic knees. Material and Methods: Ten matched pairs with either isolated partial rupture of the medial collateral ligament or combined medial collateral ligament/anterior cruciate ligament rupture were compared with matched controls 10 years after trauma. Weight-bearing radiographys and MR examinations were compared with proteoglycan fragment concentrations in the joint fluid. Results: The chemical analyses were similar in both trauma groups. The radiographs showed mild signs of arthrosis in half the patients with combined injury. MR images showed almost all injuried knees to have degenerative changes of various degrees in the cartilage and menisci. More frequent and more advanced changes were found after combined injury than after isolated injury (p<0.01). There were no changes in the controls. Conclusion: MR imaging is the best method for detecting and differentiating early posttraumatic knee arthrosis. (orig.).

  13. Computer-Based Linguistic Analysis.

    Wright, James R.

    Noam Chomsky's transformational-generative grammar model may effectively be translated into an equivalent computer model. Phrase-structure rules and transformations are tested as to their validity and ordering by the computer via the process of random lexical substitution. Errors appearing in the grammar are detected and rectified, and formal…

  14. Abdomen X-Ray (Radiography)

    ... Professions Site Index A-Z X-ray (Radiography) - Abdomen Abdominal x-ray uses a very small dose ... to produce pictures of the inside of the abdominal cavity. It is used to evaluate the stomach, liver, ...

  15. Proton Radiography (pRad)

    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...

  16. Euratom Neutron Radiography Working Group

    Domanus, Joseph Czeslaw

    1986-01-01

    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...... 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...... radiography are constituted. This paper reviews the activities and achievements of the NRWG and its sub-groups....

  17. Computer Aided Data Analysis in Sociometry

    Langeheine, Rolf

    1978-01-01

    A computer program which analyzes sociometric data is presented. The SDAS program provides classical sociometric analysis. Multi-dimensional scaling and cluster analysis techniques may be combined with the MSP program. (JKS)

  18. A new clinical unit for digital radiography based on a thick amorphous Selenium plate: Physical and psychophysical characterization

    Rivetti, Stefano; Lanconelli, Nico; Bertolini, Marco; Acchiappati, Domenico [Alma Mater Studiorum, Physics Department, University of Bologna, 40127 Bologna, Italy and S.C. di Fisica Sanitaria ' ' Azienda USL di Modena' ' 41100 Modena (Italy); Alma Mater Studiorum, Physics Department, University of Bologna, 40127 Bologna (Italy); Arcispedale Santa Maria Nuova, 42123 Reggio Emilia (Italy); S.C. di Fisica Sanitaria ' ' Azienda USL di Modena' ' 41100 Modena (Italy)

    2011-08-15

    Purpose: Here, we present a physical and psychophysical characterization of a new clinical unit (named AcSelerate) for digital radiography based on a thick a-Se layer. We also compared images acquired with and without a software filter (named CRF) developed for reducing sharpness and noise of the images and making them similar to images coming from traditional computed radiography systems. Methods: The characterization was achieved in terms of physical figures of merit [modulation transfer function (MTF), noise power spectra (NPS), detective quantum efficiency (DQE)], and psychophysical parameters (contrast-detail analysis with an automatic reading of CDRAD images). We accomplished measurements with four standard beam conditions: RAQ3, RQA5, RQA7, and RQA9. Results: The system shows an excellent MTF (about 50% at the Nyquist frequency). The DQE is about 55% at 0.5 lp/mm and above 20% at the Nyquist frequency and is almost independent from exposure. The contrast-detail curves are comparable to some of the best published data for other systems devoted to imaging in general radiography. The CRF filter influences both the MTF and NPS, but it does lead to very small changes on DQE. Also the visibility of CDRAD details is basically unaltered, when the filter is activated. Conclusions: As normally happens with detector based on direct conversion, the system presents an excellent MTF. The improved efficiency caused by the thick layer allows getting good noise characteristics and DQE results better (about 10% on average) than many of the computed radiography (CR) systems and comparable to those obtained by the best systems for digital radiography available on the market.

  19. Transportation Research & Analysis Computing Center

    Federal Laboratory Consortium — The technical objectives of the TRACC project included the establishment of a high performance computing center for use by USDOT research teams, including those from...

  20. Numerical Analysis of Multiscale Computations

    Engquist, Björn; Tsai, Yen-Hsi R

    2012-01-01

    This book is a snapshot of current research in multiscale modeling, computations and applications. It covers fundamental mathematical theory, numerical algorithms as well as practical computational advice for analysing single and multiphysics models containing a variety of scales in time and space. Complex fluids, porous media flow and oscillatory dynamical systems are treated in some extra depth, as well as tools like analytical and numerical homogenization, and fast multipole method.

  1. [Fabrication of improved multi-slit equipment to obtain the input-output characteristics of computed radiography systems: correction of the heel effect, and application to high tube-voltage experiments].

    Maehata, Itsumi; Hayashi, Hiroaki; Takegami, Kazuki; Ujita, Syohei; Kimoto, Natsumi; Konishi, Yuki; Fukuda, Ikuma

    2014-09-01

    Multi-slit equipment is a new experimental apparatus that can measure the input-output characteristics of a CR (computed radiography) system with limited influence of the fading effect. Kimoto et al. recently proposed a new type of multi-slit apparatus in which the multi-slit setup, the insertion region of the phosphor plate, and plate shielding are integrated to create a single handy-type item (an all-in-one type multi-slit apparatus). However, some problems remained unsolved. The aims of this study were to devise a setup for application to high tube voltage conditions, and to improve the all-in-one type multi-slit equipment so as to correct the heel effect. We examined the capabilities of our improved multi-slit equipment using diagnostic X-ray apparatus and found that it can obtain input-output characteristics with 5% accuracy for tube voltages of 40-140 kV and SID (source to image receptor distances) of 50-200 cm.

  2. Axial Tomography from Digitized Real Time Radiography

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

    1985-01-18

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

  3. Electronic imaging system for neutron radiography at a low power research reactor

    Ferreira, F.J.O., E-mail: fferreira@ien.gov.b [Instituto de Engenharia Nuclear, Comissao Nacional de Energia Nuclear, Caixa Postal 68550, CEP 21945-970, Rio de Janeiro (Brazil); Silva, A.X.; Crispim, V.R. [PEN/COPPE-DNC/POLI CT, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970 Rio de Janeiro (Brazil)

    2010-08-15

    This paper describes an electronic imaging system for producing real time neutron radiography from a low power research reactor, which will allow inspections of samples with high efficiency, in terms of measuring time and result analysis. This system has been implanted because of its potential use in various scientific and industrial areas where neutron radiography with photographic film could not be applied. This real time system is installed in neutron radiography facility of Argonauta nuclear research reactor, at the Instituto de Engenharia Nuclear of the Comissao Nacional de Energia Nuclear, in Brazil. It is adequate to perform real time neutron radiography of static and dynamic events of samples.

  4. Adjustment computations spatial data analysis

    Ghilani, Charles D

    2011-01-01

    the complete guide to adjusting for measurement error-expanded and updated no measurement is ever exact. Adjustment Computations updates a classic, definitive text on surveying with the latest methodologies and tools for analyzing and adjusting errors with a focus on least squares adjustments, the most rigorous methodology available and the one on which accuracy standards for surveys are based. This extensively updated Fifth Edition shares new information on advances in modern software and GNSS-acquired data. Expanded sections offer a greater amount of computable problems and their worked solu

  5. Does applying the Canadian Cervical Spine rule reduce cervical spine radiography rates in alert patients with blunt trauma to the neck? A retrospective analysis

    Yesupalan Rajam

    2008-06-01

    Full Text Available Abstract Background A cautious outlook towards neck injuries has been the norm to avoid missing cervical spine injuries. Consequently there has been an increased use of cervical spine radiography. The Canadian Cervical Spine rule was proposed to reduce unnecessary use of cervical spine radiography in alert and stable patients. Our aim was to see whether applying the Canadian Cervical Spine rule reduced the need for cervical spine radiography without missing significant cervical spine injuries. Methods This was a retrospective study conducted in 2 hospitals. 114 alert and stable patients who had cervical spine radiographs for suspected neck injuries were included in the study. Data on patient demographics, high risk & low risk factors as per the Canadian Cervical Spine rule and cervical spine radiography results were collected and analysed. Results 28 patients were included in the high risk category according to the Canadian Cervical Spine rule. 86 patients fell into the low risk category. If the Canadian Cervical Spine rule was applied, there would have been a significant reduction in cervical spine radiographs as 86/114 patients (75.4% would not have needed cervical spine radiograph. 2/114 patients who had significant cervical spine injuries would have been identified when the Canadian Cervical Spine rule was applied. Conclusion Applying the Canadian Cervical Spine rule for neck injuries in alert and stable patients would have reduced the use of cervical spine radiographs without missing out significant cervical spine injuries. This relates to reduction in radiation exposure to patients and health care costs.

  6. Digital Radiography for Determination of Primary Tooth Length: In Vivo and Ex Vivo Studies

    Maria D. Basso

    2015-01-01

    Full Text Available Background. Methods for determining the root canal length of the primary tooth should yield accurate and reproducible results. In vitro studies show some limitations, which do not allow their findings to be directly transferred to a clinical situation. Aim. To compare the accuracy of radiographic tooth length obtained from in vivo digital radiograph with that obtained from ex vivo digital radiograph. Method. Direct digital radiographs of 20 upper primary incisors were performed in teeth (2/3 radicular resorption that were radiographed by an intraoral sensor, according to the long-cone technique. Teeth were extracted, measured, and mounted in a resin block, and then radiographic template was used to standardise the sensor-target distance (30 cm. The apparent tooth length (APTL was obtained from the computer screen by means of an electronic ruler accompanying the digital radiography software (CDR 2.0, whereas the actual tooth length (ACTL was obtained by means of a digital calliper following extraction. Data were compared to the ACTL by variance analysis and Pearson’s correlation test. Results. The values for APTL obtained from in vivo radiography were slightly underestimated, whereas those values obtained from ex vivo were slightly overestimated. No significance was observed (P≤0.48 between APTL and ACTL. Conclusion. The length of primary teeth estimated by in vivo and ex vivo comparisons using digital radiography was found to be similar to the actual tooth length.

  7. EFFECTS OF X-RAY BEAM ANGLE AND GEOMETRIC DISTORTION ON WIDTH OF EQUINE THORACOLUMBAR INTERSPINOUS SPACES USING RADIOGRAPHY AND COMPUTED TOMOGRAPHY

    Djernaes, Julie D.; Nielsen, Jon V.; Berg, Lise C.

    2017-01-01

    study was to determine whether X-ray beam angle has an effect on apparent widths of interspinous spaces. Thoracolumbar spine specimens were collected from six equine cadavers and left-right lateral radiographs and sagittal and dorsal reconstructed computed tomographic (CT) images were acquired...

  8. Cluster analysis for computer workload evaluation

    Landau, K

    1976-01-01

    An introduction to computer workload analysis is given, showing its range of application in computer centre management, system and application programming. Cluster methods are discussed which can be used in conjunction with workload data and cluster algorithms are adapted to the specific set problem. Several samples of CDC 7600- accounting-data-collected at CERN, the European Organization for Nuclear Research-underwent a cluster analysis to determine job groups. The conclusions from resource usage of typical job groups in relation to computer workload analysis are discussed. (17 refs).

  9. Error Analysis In Computational Elastodynamics

    Mukherjee, Somenath; Jafarali, P.; Prathap, Gangan

    The Finite Element Method (FEM) is the mathematical tool of the engineers and scientists to determine approximate solutions, in a discretised sense, of the concerned differential equations, which are not always amenable to closed form solutions. In this presentation, the mathematical aspects of this powerful computational tool as applied to the field of elastodynamics have been highlighted, using the first principles of virtual work and energy conservation.

  10. Accuracy of Cone-beam Computed Tomography and Periapical Radiography in Endodontically Treated Teeth Evaluation: A Five-Year Retrospective Study

    2015-01-01

    Background: This study aimed to evaluate the accuracy of two imaging methods in detecting the apical pathology in endodontically treated teeth. Material and Methods: A clinical examination from a sample of 156 teeth of patients treated by students of masters in endodontics at the Care Center of the Faculty of Dentistry at St. Joseph University, Beirut was done after 5 years of follow-up. Periradicular digital radiographs and a cone-beam computed tomography (CBCT)scans were taken and analyzed ...

  11. Evaluation of diagnostic ability of CCD digital radiography in the detection of incipient dental caries

    Lee, Wan; Lee, Byung Do [Wonkwang University College of Medicine, Iksan (Korea, Republic of)

    2003-03-15

    The purpose of this experiment was to evaluate the diagnostic ability of a CCD-based digital system (CDX-2000HQ) in the detection of incipient dental caries. 93 extracted human teeth with sound proximal surfaces and interproximal artificial cavities were radiographed using 4 imaging methods. Automatically processed No.2 Insight film (Eastman Kodak Co., U.S.A.) was used for conventional radiography, scanned images of conventional radiograms for indirect digital radiography were used. For the direct digital radiography, the CDX-2000HQ CCD system (Biomedisys Co. Korea) was used. The subtraction images were made from two direct digital images by Sunny program in the CDX-2000HQ system. Two radiologists and three endodontists examined the presence of lesions using a five-point confidence scale and compared the diagnostic ability by ROC (Receiver Operating Characteristic) analysis and one way ANOVA test. The mean ROC areas of conventional radiography, indirect digital radiography, direct digital radiography, and digital subtraction radiography were 0.9093, 0.9102, 0.9184, and 0.9056, respectively. The diagnostic ability of direct digital radiography was better than the other imaging modalities, but there were no statistical differences among these imaging modalities (p>0.05). These results indicate that new CCD-based digital systems (CDX-2000HQ) have the potential to serve as an alternative to conventional radiography in the detection of incipient dental caries.

  12. Applied time series analysis and innovative computing

    Ao, Sio-Iong

    2010-01-01

    This text is a systematic, state-of-the-art introduction to the use of innovative computing paradigms as an investigative tool for applications in time series analysis. It includes frontier case studies based on recent research.

  13. IMAGING DIAGNOSIS--USE OF RADIOGRAPHY AND COMPUTED TOMOGRAPHY IN THE DIAGNOSIS OF A MINERALIZED YOLK SAC IN A BROWN KIWI (APTERYX MANTELLI).

    Wightman, Paul; Cohen, Eli B; Hunter, Stuart; Gartrell, Brett

    2015-01-01

    A 12-day-old Brown Kiwi (Apteryx mantelli) was presented with anorexia, torticollis, head-tilt, and coelomic distension. Radiographs showed an ill-defined, fat-opaque, coelomic mass displacing viscera craniodorsally. Curvilinear mineral opacities were superimposed over the ventral aspect of the mass. Computed tomography demonstrated the presence of mineral within the periphery of a fat attenuating mass consistent with a retained yolk sac. A deutectomy (yolk sac excision) was performed. Histopathology of the excised tissue confirmed the diagnosis of a retained yolk sac with multifocal mineralization.

  14. Use of fluorescent screens for isotope radiography

    Hubbard, S. K.

    1979-01-01

    Radiographic examination can be performed on items beyond the limitation of conventional isotope radiography without a great loss of resolution. With proper film and screen selection and scatter radiation control, fluorescent screens can be a valuable additional tool for radiography.

  15. Cone-beam computed tomography versus digital periapical radiography in the detection of artificially created periapical lesions: A pilot study of the diagnostic accuracy of endodontists using both techniques

    Campello, Andrea Fagundes; Gonçalves, Lucio Souza; Guedes, Fábio Ribeiro

    2017-01-01

    Purpose The aim of this study was to compare the diagnostic accuracy of previously trained endodontists in the detection of artificially created periapical lesions using cone-beam computed tomography (CBCT) and digital periapical radiography (DPR). Materials and Methods An ex vivo model using dry skulls was used, in which simulated apical lesions were created and then progressively enlarged using #1/2, #2, #4, and #6 round burs. A total of 11 teeth were included in the study, and 110 images were obtained with CBCT and with an intraoral digital periapical radiographic sensor (Instrumentarium dental, Tuusula, Finland) initially and after each bur was used. Specificity and sensitivity were calculated. All images were evaluated by 10 previously trained, certified endodontists. Agreement was calculated using the kappa coefficient. The accuracy of each method in detecting apical lesions was calculated using the chi-square test. Results The kappa coefficient between examiners showed low agreement (range, 0.17-0.64). No statistical difference was found between CBCT and DPR in teeth without apical lesions (P=.15). The accuracy for CBCT was significantly higher than for DPR in all corresponding simulated lesions (P<.001). The correct diagnostic rate for CBCT ranged between 56.9% and 73.6%. The greatest difference between CBCT and DPR was seen in the maxillary teeth (CBCT, 71.4%; DPR, 28.6%; P<.01) and multi-rooted teeth (CBCT, 83.3%; DPR, 33.3%; P<.01). Conclusion CBCT allowed higher accuracy than DPR in detecting simulated lesions for all simulated lesions tested. Endodontists need to be properly trained in interpreting CBCT scans to achieve higher diagnostic accuracy. PMID:28361026

  16. Computer Programs for Settlement Analysis.

    1980-10-01

    This report was written by Mr. Mosher and Dr. Radha- krishnan. Mr. D. L. Neumann was Chief of the ADP Center. COL J. L. Cannon , CE, and COL N. P...n. ITERMX=I00. If the number of iterations in the Gauss - Seidel subroutine reaches 100, the calculations will be aborted and the analysis stops. 69

  17. DFT computational analysis of piracetam

    Rajesh, P.; Gunasekaran, S.; Seshadri, S.; Gnanasambandan, T.

    2014-11-01

    Density functional theory calculation with B3LYP using 6-31G(d,p) and 6-31++G(d,p) basis set have been used to determine ground state molecular geometries. The first order hyperpolarizability (β0) and related properties (β, α0 and Δα) of piracetam is calculated using B3LYP/6-31G(d,p) method on the finite-field approach. The stability of molecule has been analyzed by using NBO/NLMO analysis. The calculation of first hyperpolarizability shows that the molecule is an attractive molecule for future applications in non-linear optics. Molecular electrostatic potential (MEP) at a point in the space around a molecule gives an indication of the net electrostatic effect produced at that point by the total charge distribution of the molecule. The calculated HOMO and LUMO energies show that charge transfer occurs within these molecules. Mulliken population analysis on atomic charge is also calculated. Because of vibrational analysis, the thermodynamic properties of the title compound at different temperatures have been calculated. Finally, the UV-Vis spectra and electronic absorption properties are explained and illustrated from the frontier molecular orbitals.

  18. Computer Graphics for System Effectiveness Analysis.

    1986-05-01

    02139, August 1982. Chapra , Steven C., and Raymond P. Canale, (1985), Numerical Methods for Engineers with Personal Computer Applications New York...I -~1.2 Outline of Thesis .................................. 1..... .......... CHAPTER 11. METHOD OF ANALYSIS...Chapter VII summarizes the results and gives recommendations for future research. I - P** METHOD OF ANALYSIS 2.1 Introduction Systems effectiveness

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

    Mohamed, Abdul Aziz; Wahab, Aliff Amiru Bin [Universiti Tenaga Nasional, Jalan IKRAM-UNITEN, 43000 Kajang, Selangor (Malaysia); Yazid, Hafizal B.; Ahmad, Megat Harun Al Rashid B. Megat; Jamro, Rafhayudi B.; Azman, Azraf B.; Zin, Muhamad Rawi Md; Idris, Faridah Mohamad [Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia)

    2014-02-12

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

  20. Computer Auxiliary Analysis for Stochasticity of Chaos

    ZHAOGeng; FANGJin-qing

    2003-01-01

    In this work, we propose a mathematics-physical statistic analytical method for stochastic process of chaos, based on stochastic test via combination measurement of Monobit and Runs. Computer auxiliary analysis shows that it is of stochasticity for stochastic number produced from the chaotic circuit. Our software is written by VB and C++, the later can be tested by the former, and at the same time it is verified by stochastic number produced by the computer. So the data treatment results are reliable.

  1. Computer Language Effciency via Data Envelopment Analysis

    Andrea Ellero

    2011-01-01

    Full Text Available The selection of the computer language to adopt is usually driven by intuition and expertise, since it is very diffcult to compare languages taking into account all their characteristics. In this paper, we analyze the effciency of programming languages through Data Envelopment Analysis. We collected the input data from The Computer Language Benchmarks Game: we consider a large set of languages in terms of computational time, memory usage, and source code size. Various benchmark problems are tackled. We analyze the results first of all considering programming languages individually. Then, we evaluate families of them sharing some characteristics, for example, being compiled or interpreted.

  2. Experiments on muon radiography with emulsion track detectors

    Aleksandrov Andrey

    2016-01-01

    Full Text Available Muon radiography is a method of study the internal structure of large natural and industrial objects based on sensing an object with a flux of cosmic muons with their subsequent registration and analysis of the pattern of their dispersion, or conplete (or partial absorption. The Lebedev Physical Institute of the Russian Academy of Sciences and the Skobeltsyn Institute of Nuclear Physics of Moscow State University have started a series of muon radiography experiments with nuclear emulsion detectors. As a result, the optimal conditions for experiment arrangement have been determined, algorithms of data processing have been worked out, and peculiarities of the method have been ultimately investigated.

  3. Analysis by synchrotron X-ray radiography of convection effects on the dynamic evolution of the solid-liquid interface and on solute distribution during the initial transient of solidification

    Bogno, A., E-mail: abdoul-aziz.bogno@im2np.fr [Aix Marseille Universite, Campus Saint-Jerome, Case 142, 13397 Marseille Cedex 20 (France); CNRS, UMR 6242, Campus Saint-Jerome, Case 142, 13397 Marseille Cedex 20 (France); Nguyen-Thi, H. [Aix Marseille Universite, Campus Saint-Jerome, Case 142, 13397 Marseille Cedex 20 (France); CNRS, UMR 6242, Campus Saint-Jerome, Case 142, 13397 Marseille Cedex 20 (France); Buffet, A. [ESRF, Avenue des Martyrs, BP 220, 38048 Grenoble Cedex (France); Reinhart, G.; Billia, B.; Mangelinck-Noel, N.; Bergeon, N. [Aix Marseille Universite, Campus Saint-Jerome, Case 142, 13397 Marseille Cedex 20 (France); CNRS, UMR 6242, Campus Saint-Jerome, Case 142, 13397 Marseille Cedex 20 (France); Baruchel, J. [ESRF, Avenue des Martyrs, BP 220, 38048 Grenoble Cedex (France); Schenk, T. [LPM - ENSMN, Parc de Saurupt, 54042 Nancy Cedex (France)

    2011-06-15

    In situ monitoring of the initial transient of directional solidification was carried out by means of synchrotron X-ray radiography. Experiments with Al-4 wt.% Cu alloy samples were performed on beamline ID19 of the European Synchrotron Radiation Facility (ESRF) in a dedicated Bridgman-type furnace. X-ray radiography enabled a detailed analysis of the evolution over time of the solid-liquid interface macroscopic shape in interaction with convection in the melt. Lateral solute segregation induced by fluid flow resulted in a significant deformation of the solid-liquid interface. The time-dependent velocity of the solidification front was determined at different abscissa values along the curved interface during the solidification process, from the growth phase with a smooth interface to the onset of morphological instability. Further, using a novel quantitative image analysis technique we were able to measure longitudinal solute profiles in the melt during the initial transient. Solutal length was then deduced as well as concentration in the melt, both at the interface and far away from it. The influence of convection on growth velocity and the characteristic parameters of the solute boundary layer are discussed, and a comparison with the Warren and Langer model is also presented.

  4. ASTEC: Controls analysis for personal computers

    Downing, John P.; Bauer, Frank H.; Thorpe, Christopher J.

    1989-01-01

    The ASTEC (Analysis and Simulation Tools for Engineering Controls) software is under development at Goddard Space Flight Center (GSFC). The design goal is to provide a wide selection of controls analysis tools at the personal computer level, as well as the capability to upload compute-intensive jobs to a mainframe or supercomputer. The project is a follow-on to the INCA (INteractive Controls Analysis) program that has been developed at GSFC over the past five years. While ASTEC makes use of the algorithms and expertise developed for the INCA program, the user interface was redesigned to take advantage of the capabilities of the personal computer. The design philosophy and the current capabilities of the ASTEC software are described.

  5. Correction parameters in conventional dental radiography for dental implant

    Barunawaty Yunus

    2009-12-01

    Full Text Available Background: Radiographic imaging as a supportive diagnostic tool is the essential component in treatment planning for dental implant. It help dentist to access target area of implant due to recommendation of many inventions in making radiographic imaging previously. Along with the progress of science and technology, the increasing demand of easier and simpler treatment method, a modern radiographic diagnostic for dental implant is needed. In fact, Makassar, especially in Faculty of Dentistry Hasanuddin University, has only a conventional dental radiography. Researcher wants to optimize the equipment that is used to obtain parameters of the jaw that has been corrected to get accurate dental implant. Purpose: This study aimed to see the difference of radiographic imaging of dental implant size which is going to be placed in patient before and after correction. Method: The type of research is analytical observational with cross sectional design. Sampling method is non random sampling. The amount of samples is 30 people, male and female, aged 20–50 years old. The correction value is evaluated from the parameter result of width, height, and thick of the jaw that were corrected with a metal ball by using conventional dental radiography to see the accuracy. Data is analyzed using SPSS 14 for Windows program with T-test analysis. Result: The result that is obtained by T-Test analysis results with significant value which p<0.05 in the width and height of panoramic radiography technique, the width and height of periapical radiography technique, and the thick of occlusal radiography technique before and after correction. Conclusion: It can be concluded that there is a significant difference before and after the results of panoramic, periapical, and occlusal radiography is corrected.

  6. The computer in shell stability analysis

    Almroth, B. O.; Starnes, J. H., Jr.

    1975-01-01

    Some examples in which the high-speed computer has been used to improve the static stability analysis capability for general shells are examined. The fundamental concepts of static stability are reviewed with emphasis on the differences between linear bifurcation buckling and nonlinear collapse. The analysis is limited to the stability of conservative systems. Three examples are considered. The problem of cylinders subjected to bending loads is used as an example to illustrate that a simple structure can have a sufficiently complicated nonlinear behavior to require a computer analysis for accurate results. An analysis of the problems involved in the modeling of stiffening elements in plate and shell structures illustrates the necessity that the analyst recognizes all important deformation modes. The stability analysis of the Skylab structure indicates the size of problems that can be solved with current state-of-the-art capability.

  7. Impact of chest radiography for children with lower respiratory tract infection: a propensity score approach.

    Emmanuelle Ecochard-Dugelay

    Full Text Available BACKGROUND: Management of acute respiratory tract infection varies substantially despite this being a condition frequently encountered in pediatric emergency departments. Previous studies have suggested that the use of antibiotics was higher when chest radiography was performed. However none of these analyses had considered the inherent indication bias of observational studies. OBJECTIVE: The aim of this work was to assess the relationship between performing chest radiography and prescribing antibiotics using a propensity score analysis to address the indication bias due to non-random radiography assignment. METHODS: We conducted a prospective study of 697 children younger than 2 years of age who presented during the winter months of 2006-2007 for suspicion of respiratory tract infection at the Pediatric Emergency Department of an urban general hospital in France (Paris suburb. We first determined the individual propensity score (probability of having a chest radiography according to baseline characteristics. Then we assessed the relation between radiography and antibiotic prescription using two methods: adjustment and matching on the propensity score. RESULTS: We found that performing a chest radiography lead to more frequent antibiotic prescription that may be expressed as OR = 2.3, CI [1.3-4.1], or as an increased use of antibiotics of 18.6% [0.08-0.29] in the group undergoing chest radiography. CONCLUSION: Chest radiography has a significant impact on the management of infants admitted for suspicion of respiratory tract infection in a pediatric emergency department and may lead to unnecessary administration of antibiotics.

  8. Utility of lead thyroid collar in cephalometric radiography

    Anuraag B Choudhary

    2012-01-01

    Conclusions : Lead shielding of the thyroid gland does not affect landmark identification or the specific measurements of the angulations traced during cephalometric analysis. TCs should be routinely applied during cephalometric radiography if cephalometric analyses are limited to the structures above the second cervical vertebra.

  9. Computation for the analysis of designed experiments

    Heiberger, Richard

    2015-01-01

    Addresses the statistical, mathematical, and computational aspects of the construction of packages and analysis of variance (ANOVA) programs. Includes a disk at the back of the book that contains all program codes in four languages, APL, BASIC, C, and FORTRAN. Presents illustrations of the dual space geometry for all designs, including confounded designs.

  10. Machine learning applied to proton radiography

    Chen, Nicholas Fang Yew; Ceurvorst, Luke; Ratan, Naren; Sadler, James; Levy, Matthew; Trines, Raoul; Bingham, Robert; Norreys, Peter

    2016-01-01

    Proton radiography is a technique extensively used to resolve magnetic field structures in high energy density plasmas, revealing a whole variety of interesting phenomena such as magnetic reconnection and collisionless shocks found in astrophysical systems. Existing methods of analyzing proton radiographs give mostly qualitative results or specific quantitative parameters such as magnetic field strength, and recent work showed that the line-integrated transverse magnetic field can be reconstructed in specific regimes where many simplifying assumptions were needed. Using artificial neural networks, we suggest a novel 3-D reconstruction method that works for a more general case. A proof of concept is presented here, with mean reconstruction errors of less than 5 percent even after introducing noise. We demonstrate that over the long term, this approach is more computationally efficient compared to other techniques. We also highlight the need for proton tomography because (i) certain field structures cannot be r...

  11. Nuclear track radiography of 'hot' aerosol particles

    Boulyga, S F; Kievets, M K; Lomonosova, E M; Zhuk, I V; Yaroshevich, O I; Perelygin, V P; Petrova, R I; Brandt, R; Vater, P

    1999-01-01

    Nuclear track radiography was applied to identify aerosol 'hot' particles which contain elements of nuclear fuel and fallout after Chernobyl NPP accident. For the determination of the content of transuranium elements in radioactive aerosols the measurement of the alpha-activity of 'hot' particles by SSNTD was used in this work, as well as radiography of fission fragments formed as a result of the reactions (n,f) and (gamma,f) in the irradiation of aerosol filters by thermal neutrons and high energy gamma quanta. The technique allowed the sizes and alpha-activity of 'hot' particles to be determined without extracting them from the filter, as well as the determination of the uranium content and its enrichment by sup 2 sup 3 sup 5 U, sup 2 sup 3 sup 9 Pu and sup 2 sup 4 sup 1 Pu isotopes. Sensitivity of determination of alpha activity by fission method is 5x10 sup - sup 6 Bq per particle. The software for the system of image analysis was created. It ensured the identification of track clusters on an optical imag...

  12. Muon radiography and deformation analysis of the lava dome formed by the 1944 eruption of Usu, Hokkaido--contact between high-energy physics and volcano physics--.

    K M Tanaka, Hiroyuki; Yokoyama, Izumi

    2008-01-01

    Lava domes are one of the conspicuous topographic features on volcanoes. The subsurface structure of the lava dome is important to discuss its formation mechanism. In the 1944 eruption of Volcano Usu, Hokkaido, a new lava dome was formed at its eastern foot. After the completion of the lava dome, various geophysical methods were applied to the dome to study its subsurface structure, but resulted in a rather ambiguous conclusion. Recently, from the results of the levelings, which were repeated during the eruption, "pseudo growth curves" of the lava dome were obtained. The curves suggest that the lava dome has a bulbous shape. In the present work, muon radiography, which previously proved effective in imaging the internal structure of Volcano Asama, has been applied to the Usu lava dome. The muon radiography measures the distribution of the "density length" of volcanic bodies when detectors are arranged properly. The result obtained is consistent with the model deduced from the pseudo growth curves. The measurement appears to afford useful method to clarify the subsurface structure of volcanoes and its temporal changes, and in its turn to discuss volcanic processes. This is a point of contact between high-energy physics and volcano physics.

  13. Computer-aided power systems analysis

    Kusic, George

    2008-01-01

    Computer applications yield more insight into system behavior than is possible by using hand calculations on system elements. Computer-Aided Power Systems Analysis: Second Edition is a state-of-the-art presentation of basic principles and software for power systems in steady-state operation. Originally published in 1985, this revised edition explores power systems from the point of view of the central control facility. It covers the elements of transmission networks, bus reference frame, network fault and contingency calculations, power flow on transmission networks, generator base power setti

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

    Theocharopoulos, Nicholas; Chatzakis, Georgios; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, Iraklion, 71003 Crete (Greece) and Department of Natural Sciences, Technological Education Institute of Crete, P.O. Box 140, Iraklion 71004 Crete (Greece); Department of Radiology, Faculty of Medicine, University of Crete, P.O. Box 2208, Iraklion, 71003 Crete (Greece); Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, Iraklion, 71003 Crete (Greece)

    2009-10-15

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

  15. The application and development of radiography technology based on x-ray

    Chen, Hao; Xu, Zhou; Li, Ming

    2009-07-01

    Modern Radiography technology was combined with radiation physics and modern imaging processing, which was an important branch of information obtainment and processing. We can get the inside information of the object, by the X ray's attenuation when the ray penetrated the object, and depending on the computer's fast processing, we can see the slice imaging of the object. Computerized Tomography, Computerized Laminography, and Digital Radiography were important parts in Radiography. The institute of applied electronics, CAEP in the research of intense radiation had developed several advanced radiation sources and some advanced radiography imaging systems, for example, S-band small spot linear accelerator, full solid state modulator, C-band linear accelerator, high energy Tera-hertz radiation source and CT technology based on cone beam, DR technology, CL Technology etc. Such imaging systems had been applied in industrial NDT/NDE, security check, medical diagnosis, petroleum and gas pipeline inspection system etc.

  16. Neutron induced electron radiography; Radiografia com eletrons induzida por neutrons

    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)

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

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

    1988-04-01

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

  18. 76 FR 60939 - Metal Fatigue Analysis Performed by Computer Software

    2011-09-30

    ... COMMISSION Metal Fatigue Analysis Performed by Computer Software AGENCY: Nuclear Regulatory Commission... applicants' analyses and methodologies using the computer software package, WESTEMS TM , to demonstrate... by Computer Software Addressees All holders of, and applicants for, a power reactor operating...

  19. Contribution of computed tomography in patients with lung metastases of differentiated thyroid carcinoma not apparent on plain radiography who were treated with radioiodine; Contribuicao da tomografia computadorizada em pacientes com metastases pulmonares de carcinoma diferenciado de tireoide nao-aparentes na radiografia e tratados com radioiodo

    Rosario, Pedro W.S.; Purisch, Saulo [Santa Casa Belo Horizonte, MG (Brazil). Dep. de Tireoide. Servico de Endocrinologia]. E-mail: pedrorosario@globo.com; Tavares, Wilson C. [Instituto Alpha de Gastroenterologia, Belo Horizonte, MG (Brazil); Barroso, Alvarao L.; Rezende, Leonardo L.; Padrao, Eduardo L. [Santa Casa Belo Horizonte, MG (Brazil). Servico de Medicina Nuclear

    2008-02-15

    Computed tomography (CT or CAT Scan) of the chest is more sensitive than radiography in the detection of lung metastases of differentiated thyroid cancer (DTC), but little information is available regarding the aggregated value of this method. The present study evaluated the response of patients with lung metastases of DTC not apparent on radiography to treatment with {sup 131}I and the value of CT in these cases. Twenty-five patients with lung metastases not apparent on radiography, who initially received 100-200 mCi I{sup 151}, were evaluated and those presenting pulmonary uptake on post-therapy WBS were submitted to a new treatment after 6 to 12 months, and so on. The chance of detection of pulmonary uptake on post-therapy WBS did not differ between patients with negative and positive CT (100% versus 91.5%). Mean serum Tg levels were higher in patients with positive CT (108 ng/ml versus 52 ng/ml). Negative post-therapy WBS was achieved in 82% of patients with positive CT and in 92.3% with negative CT and the cumulative I{sup 131} activity necessary to achieve this outcome did not differ between the two groups (mean = 300 mCi). Stimulated Tg was undetectable in 47% of patients with negative CT at the end of treatment, but in none of the patients whose CT continued to be positive. In patients with elevated Tg, the CT result apparently did not change the indication of therapy or the I{sup 131} activity to be administered. In cases with lung metastases, the persistence of micronodules on CT was associated with the persistence of detectable Tg in patients presenting negative post-therapy WBS. (author)

  20. Multiple imaging radiography at LNLS

    Hoennicke, M.G. [LORXI, Departamento de Fisica, Universidade Federal do Parana, Caixa Postal 19091, 81531-990 Curitiba (Brazil)], E-mail: marcelohonnicke@yahoo.com.br; Cusatis, C. [LORXI, Departamento de Fisica, Universidade Federal do Parana, Caixa Postal 19091, 81531-990 Curitiba(Brazil); Antunes, A. [Departamento de Fisica Aplicada, Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05315-970 Sao Paulo (Brazil); Safatle, A.M.V.; Barros, P.S.M. [Laboratorio de Oftalmologia Experimental e Comparativa, Departamento de Cirurgia, Faculdade de Medicina Veterinaria, Universidade de Sao Paulo, 05508-900 Sao Paulo (Brazil); Morelhao, S.L. [Departamento de Fisica Aplicada, Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05315-970 Sao Paulo (Brazil)

    2008-01-11

    An analyzer-based X-ray phase-contrast imaging (ABI) setup has been mounted at the Brazilian Synchrotron Light Laboratory (LNLS) for multiple imaging radiography (MIR) purposes. The algorithm employed for treating the MIR data collected at LNLS is described, and its reliability in extracting the distinct types of contrast that can be obtained with MIR is demonstrated by analyzing a test sample (thin polyamide wire). As a practical application, the possibility of studying ophthalmic tissues, corneal sequestra in this case, via MIR is investigated.

  1. Oral history in radiography: Listening to pioneers

    Ferris, Christine [International Development Facilitator, Robert Winston Building, Faculty of Health and Wellbeing, Sheffield Hallam University, Sheffield S10 2BP (United Kingdom)], E-mail: c.m.ferris@shu.ac.uk; Winslow, Michelle [University of Sheffield, Oral History Society, Academic Unit of Supportive Care, Sykes House, Little Common Lane, Sheffield S11 9NE (United Kingdom)], E-mail: m.winslow@sheffield.ac.uk

    2009-12-15

    We explore the professional value of the collection and analysis of oral histories in the history of radiography. Drawing on oral histories collected from radiographers, we analyse accounts of experiences to identify common themes, some of which are of current significance, whilst others have faded from existence. 15 oral histories were collected from radiographers whose combined practice spans the years 1930-1973. The sample consists of 6 male and 9 female radiographers. Themes identified in the oral histories include radiographers as invisible pioneers who worked in professionally unclaimed territory and their dangerous working environment. The oral histories reveal the working world of the radiographer as having encompassed a practice ethos where challenges became an accepted part of work. We gain insight into less observable aspects of the radiographer's role, the difficulties they faced, how they invented techniques and equipment, and how they managed their practice including protecting the public from ionising radiation sources.

  2. NEUTRON RADIOGRAPHY: A SECOND PROGRESS REPORT

    Berger, H

    1962-08-31

    The progress made on investigations of neutron radiography since October 1960 is discussed. The problems of the production of the neutron image will be discussed. The emphasis will be on the characteristics of many of the photographic imaging methods which can be used for neutron radiography. (auth)

  3. Diagnostic ability of panoramic radiography for mandibular fractures

    Lee, Ji Hyun; Jung, Yun Hoa; Cho Bong Hae; Hwang, Dae Seok [School of Dentistry, Pusan National University, Pusan (Korea, Republic of)

    2010-03-15

    The purpose of this study was to evaluate the diagnostic efficacy of panoramic radiographs for detection of mandibular fractures. The sample was comprised of 65 patients (55 fractured, 10 non-fractured) with 92 fracture sites confirmed by multi-detector computed tomography (CT). Panoramic radiographs were evaluated for mandibular fractures by six examiners; two oral and maxillofacial radiologists (observer A and B), two oral and maxillofacial surgeons (observer C and D), and two general dentists (observer E and F). Sensitivity of panoramic radiography for mandibular fractures was 95.7% in observer A and B, 93.5% in observer C and D and 80.4% in observer E and F. The lowest sensitivity was shown in symphyseal/parasymphyseal areas, followed by subcondylar/condylar regions. Panoramic radiography is adequate for detection of mandibular fractures. However, additional multidetector CT is recommended to ascertain some indecisive fractures of symphysis and condyle, and in complicated fractures.

  4. Computational analysis of aircraft pressure relief doors

    Schott, Tyler

    Modern trends in commercial aircraft design have sought to improve fuel efficiency while reducing emissions by operating at higher pressures and temperatures than ever before. Consequently, greater demands are placed on the auxiliary bleed air systems used for a multitude of aircraft operations. The increased role of bleed air systems poses significant challenges for the pressure relief system to ensure the safe and reliable operation of the aircraft. The core compartment pressure relief door (PRD) is an essential component of the pressure relief system which functions to relieve internal pressure in the core casing of a high-bypass turbofan engine during a burst duct over-pressurization event. The successful modeling and analysis of a burst duct event are imperative to the design and development of PRD's to ensure that they will meet the increased demands placed on the pressure relief system. Leveraging high-performance computing coupled with advances in computational analysis, this thesis focuses on a comprehensive computational fluid dynamics (CFD) study to characterize turbulent flow dynamics and quantify the performance of a core compartment PRD across a range of operating conditions and geometric configurations. The CFD analysis was based on a compressible, steady-state, three-dimensional, Reynolds-averaged Navier-Stokes approach. Simulations were analyzed, and results show that variations in freestream conditions, plenum environment, and geometric configurations have a non-linear impact on the discharge, moment, thrust, and surface temperature characteristics. The CFD study revealed that the underlying physics for this behavior is explained by the interaction of vortices, jets, and shockwaves. This thesis research is innovative and provides a comprehensive and detailed analysis of existing and novel PRD geometries over a range of realistic operating conditions representative of a burst duct over-pressurization event. Further, the study provides aircraft

  5. Introduction to scientific computing and data analysis

    Holmes, Mark H

    2016-01-01

    This textbook provides and introduction to numerical computing and its applications in science and engineering. The topics covered include those usually found in an introductory course, as well as those that arise in data analysis. This includes optimization and regression based methods using a singular value decomposition. The emphasis is on problem solving, and there are numerous exercises throughout the text concerning applications in engineering and science. The essential role of the mathematical theory underlying the methods is also considered, both for understanding how the method works, as well as how the error in the computation depends on the method being used. The MATLAB codes used to produce most of the figures and data tables in the text are available on the author’s website and SpringerLink.

  6. FORTRAN computer program for seismic risk analysis

    McGuire, Robin K.

    1976-01-01

    A program for seismic risk analysis is described which combines generality of application, efficiency and accuracy of operation, and the advantage of small storage requirements. The theoretical basis for the program is first reviewed, and the computational algorithms used to apply this theory are described. The information required for running the program is listed. Published attenuation functions describing the variation with earthquake magnitude and distance of expected values for various ground motion parameters are summarized for reference by the program user. Finally, suggestions for use of the program are made, an example problem is described (along with example problem input and output) and the program is listed.

  7. Social sciences via network analysis and computation

    Kanduc, Tadej

    2015-01-01

    In recent years information and communication technologies have gained significant importance in the social sciences. Because there is such rapid growth of knowledge, methods and computer infrastructure, research can now seamlessly connect interdisciplinary fields such as business process management, data processing and mathematics. This study presents some of the latest results, practices and state-of-the-art approaches in network analysis, machine learning, data mining, data clustering and classifications in the contents of social sciences. It also covers various real-life examples such as t

  8. Analysis of a Model for Computer Virus Transmission

    Peng Qin

    2015-01-01

    Full Text Available Computer viruses remain a significant threat to computer networks. In this paper, the incorporation of new computers to the network and the removing of old computers from the network are considered. Meanwhile, the computers are equipped with antivirus software on the computer network. The computer virus model is established. Through the analysis of the model, disease-free and endemic equilibrium points are calculated. The stability conditions of the equilibria are derived. To illustrate our theoretical analysis, some numerical simulations are also included. The results provide a theoretical basis to control the spread of computer virus.

  9. Symbolic Computing in Probabilistic and Stochastic Analysis

    Kamiński Marcin

    2015-12-01

    Full Text Available The main aim is to present recent developments in applications of symbolic computing in probabilistic and stochastic analysis, and this is done using the example of the well-known MAPLE system. The key theoretical methods discussed are (i analytical derivations, (ii the classical Monte-Carlo simulation approach, (iii the stochastic perturbation technique, as well as (iv some semi-analytical approaches. It is demonstrated in particular how to engage the basic symbolic tools implemented in any system to derive the basic equations for the stochastic perturbation technique and how to make an efficient implementation of the semi-analytical methods using an automatic differentiation and integration provided by the computer algebra program itself. The second important illustration is probabilistic extension of the finite element and finite difference methods coded in MAPLE, showing how to solve boundary value problems with random parameters in the environment of symbolic computing. The response function method belongs to the third group, where interference of classical deterministic software with the non-linear fitting numerical techniques available in various symbolic environments is displayed. We recover in this context the probabilistic structural response in engineering systems and show how to solve partial differential equations including Gaussian randomness in their coefficients.

  10. Computer network environment planning and analysis

    Dalphin, John F.

    1989-01-01

    The GSFC Computer Network Environment provides a broadband RF cable between campus buildings and ethernet spines in buildings for the interlinking of Local Area Networks (LANs). This system provides terminal and computer linkage among host and user systems thereby providing E-mail services, file exchange capability, and certain distributed computing opportunities. The Environment is designed to be transparent and supports multiple protocols. Networking at Goddard has a short history and has been under coordinated control of a Network Steering Committee for slightly more than two years; network growth has been rapid with more than 1500 nodes currently addressed and greater expansion expected. A new RF cable system with a different topology is being installed during summer 1989; consideration of a fiber optics system for the future will begin soon. Summmer study was directed toward Network Steering Committee operation and planning plus consideration of Center Network Environment analysis and modeling. Biweekly Steering Committee meetings were attended to learn the background of the network and the concerns of those managing it. Suggestions for historical data gathering have been made to support future planning and modeling. Data Systems Dynamic Simulator, a simulation package developed at NASA and maintained at GSFC was studied as a possible modeling tool for the network environment. A modeling concept based on a hierarchical model was hypothesized for further development. Such a model would allow input of newly updated parameters and would provide an estimation of the behavior of the network.

  11. Assessement of rheumatic diseases with computational radiology: current status and future potential

    Peloschek, Philipp; Boesen, Mikael; Donner, Rene;

    2009-01-01

    In recent years, several computational image analysis methods to assess disease progression in rheumatic diseases were presented. This review article explains the basics of these methods as well as their potential application in rheumatic disease monitoring, it covers radiography, sonography...... as well as magnetic resonance imaging in quantitative analysis frameworks....

  12. Twenty-degree-tilt radiography for evaluation of lateral humeral condylar fracture in children

    Imada, Hideaki; Tanaka, Ryuji; Itoh, Yohei; Kishi, Kazuhiko [National Hospital Organization, Higashi-Hiroshima Medical Center, Department of Orthopedic Surgery, Higashi Hiroshima, Hiroshima (Japan)

    2010-03-15

    To investigate the efficacy of '20 -tilt anteroposterior (A-P) radiography' in the assessment of lateral condylar fractures of the distal humerus. Eighteen children with lateral humeral condylar fractures were studied. Every child underwent conventional A-P and lateral radiography, and six children underwent multi-detector computed tomography (MDCT). For the investigation of 20 -tilt radiography, ten children with lateral humeral condylar fractures had conventional and 20 -tilt A-P and lateral radiography both preoperatively and postoperatively. Fragment dislocation was measured at the lateral and medial margins of the fracture on both the conventional A-P and 20 -tilt A-P radiographs. The lateral condylar fragment was triangular and was most prominent posteriorly. The fracture line was typically tilted approximately 20 to a reference line perpendicular to the long axis of the humerus in the lateral view. The extent of dislocation at the lateral and medial margins of the fracture site by 20 -tilt A-P radiography (9.3 {+-} 3.6 mm and 5.6 {+-} 2.5 mm) was significantly wider than that measured by the conventional method (6.8 {+-} 4.1 mm and 2.0 {+-} 1.5 mm), which may influence treatment. Twenty-degree-tilt A-P radiography may more precisely demonstrate fragment dislocation than standard radiographs and may influence patient treatment. (orig.)

  13. An experimental comparative study of radiography, ultrasonography and CT imaging in the IV catheter fragment

    Kweon, Dae Cheol [Dept. of Radiological Science, College of Health Science, Shinhan University, Uijeongbu (Korea, Republic of)

    2016-06-15

    The objective of this study was to detect the fragments generated during IV (intravenous) catheter injection of contrast medium and drug administration in a clinical setting and removal was performed by experimentally producing a phantom, and to compare the radiography, ultrasonography, and multi-detector computed tomography (MDCT) imaging and radiation dose. A 1 cm fragment of an 18 gage Teflon® IV catheter with saline was inserted into the IV control line. Radiography, CT, and ultrasonography were performed and radiography and CT dose were calculated. CT and ultrasonography showed an IV catheter fragment clinically and radiography showed no visible difference in the ability to provide a useful image of an IV catheter fragment modality (p >.05). Radiography of effective dose (0.2139 mSv·Gy-1·cm-2) form DAP DAP (0.93 μGy·m2 ), and dose length product (DLP) (201 mGy·cm) to effective dose was calculated as 0.483 mSv. IV catheter fragment were detected of radiography, ultrasonography and CT. These results can be obtained by menas of an excellent IV catheter fragment of detection capability CT. However, CT is followed by radiation exposure. IV catheter fragment confirming the position and information recommend an ultrasonography.

  14. Pooled shRNA screenings: computational analysis.

    Yu, Jiyang; Putcha, Preeti; Califano, Andrea; Silva, Jose M

    2013-01-01

    Genome-wide RNA interference screening has emerged as a powerful tool for functional genomic studies of disease-related phenotypes and the discovery of molecular therapeutic targets for human diseases. Commercial short hairpin RNA (shRNA) libraries are commonly used in this area, and state-of-the-art technologies including microarray and next-generation sequencing have emerged as powerful methods to analyze shRNA-triggered phenotypes. However, computational analysis of this complex data remains challenging due to noise and small sample size from such large-scaled experiments. In this chapter we discuss the pipelines and statistical methods of processing, quality assessment, and post-analysis for both microarray- and sequencing-based screening data.

  15. FMEA Based Risk Assessment of Component Failure Modes in Industrial Radiography

    Pandey, Alok; Sonawane, A U; Rawat, Prashant S

    2016-01-01

    Industrial radiography has its inimitable role in non-destructive examinations. Industrial radiography devices, consisting of significantly high activity of the radioisotopes, are operated manually by remotely held control unit. Malfunctioning of these devices may cause potential exposure to the operator and nearby public, and thus should be practiced under a systematic risk control. To ensure the radiation safety, proactive risk assessment should be implemented. Risk assessment in industrial radiography using the Failure Modes & Effect Analysis (FMEA) for the design and operation of industrial radiography exposure devices has been carried out in this study. Total 56 component failure modes were identified and Risk Priority Numbers (RPNs) were assigned by the FMEA expert team, based on the field experience and reported failure data of various components. Results shows all the identified failure modes have RPN in the range of 04 to 216 and most of the higher RPN are due to low detectability and high severi...

  16. Detection of external apical root resorption by using cone-beam computed tomography and panoramic radiography%锥形束CT和全颌曲面断层片在根尖区牙根外吸收诊断中的对比研究

    任洪芋; 陈军; 邓锋; 郑雷蕾; 刘雄; 董艳玲

    2013-01-01

    Objective: To compare cone - beam computed tomography (CBCT) with panoramic radiography in evaluating simulated external apical root resorption (EARR). Methods: The study sample comprised 80 single - rooted premolars used for simulating 4 degrees of EARR: no (intact teeth), mild (cavity of 1.0 mm in diameter and depth in root surface), moderate (1.0 mm root shortening), and severe(3.0 mm root shortening). Two calibrated examiners assessed blindly the severity of simulated EARR on the CBCT images and the corresponding panoramic images. Results: Significant differences were found between the two imaging techniques: 100% and 27.5% of mild EARR were correctly classified by CBCT and panoramic radiography, respectively (P < 0.001); 81.9% and 64.4% of all EARR were correctly classified by CBCT and panoramic radiography, respectively (P < 0.001). Conclusion: Apical root resorption is easier to be evaluated on CBCT imaging, compared with panoramic radiography. CBCT might be a useful complementary diagnostic method to panoramic radiography, to be applied in the early diagnosis of orthodontically induced EARR.%目的:比较锥形束CT(cone-beam computed tom CT)和全颌曲面断层片(全景片)在根尖区牙根外吸收(根尖吸收)诊断中的差异.方法:选取80颗单根前磨牙,用以模拟4种不同程度的根尖吸收:无(完整的牙根)、轻度(根尖区表面1.0mm直径和深度的洞形)、中度(1.0mm牙根缩短)、重度(3.0mm牙根缩短).模拟完成后,对所有牙齿拍摄CBCT和全景片获取两组X线图像.两名正畸医师通过对图像资料的分析独立地评估所有根尖吸收的严重程度.结果:采用CBCT和全景片评估轻度根尖吸收的正确率分别为100%和27.5%,差异有统计学意义(P< 0.001);评估全部根尖吸收的正确率分别为81.9%和64.4%,差异有统计学意义(P<0.001).结论:相比于全景片,CBCT对根尖吸收具有更高的敏感度.在正畸临床中,CBCT可用于对根尖吸收

  17. Computational Analysis of Human Blood Flow

    Panta, Yogendra; Marie, Hazel; Harvey, Mark

    2009-11-01

    Fluid flow modeling with commercially available computational fluid dynamics (CFD) software is widely used to visualize and predict physical phenomena related to various biological systems. In this presentation, a typical human aorta model was analyzed assuming the blood flow as laminar with complaint cardiac muscle wall boundaries. FLUENT, a commercially available finite volume software, coupled with Solidworks, a modeling software, was employed for the preprocessing, simulation and postprocessing of all the models.The analysis mainly consists of a fluid-dynamics analysis including a calculation of the velocity field and pressure distribution in the blood and a mechanical analysis of the deformation of the tissue and artery in terms of wall shear stress. A number of other models e.g. T branches, angle shaped were previously analyzed and compared their results for consistency for similar boundary conditions. The velocities, pressures and wall shear stress distributions achieved in all models were as expected given the similar boundary conditions. The three dimensional time dependent analysis of blood flow accounting the effect of body forces with a complaint boundary was also performed.

  18. Proton Radiography at Los Alamos

    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.

  19. Computational System For Rapid CFD Analysis In Engineering

    Barson, Steven L.; Ascoli, Edward P.; Decroix, Michelle E.; Sindir, Munir M.

    1995-01-01

    Computational system comprising modular hardware and software sub-systems developed to accelerate and facilitate use of techniques of computational fluid dynamics (CFD) in engineering environment. Addresses integration of all aspects of CFD analysis process, including definition of hardware surfaces, generation of computational grids, CFD flow solution, and postprocessing. Incorporates interfaces for integration of all hardware and software tools needed to perform complete CFD analysis. Includes tools for efficient definition of flow geometry, generation of computational grids, computation of flows on grids, and postprocessing of flow data. System accepts geometric input from any of three basic sources: computer-aided design (CAD), computer-aided engineering (CAE), or definition by user.

  20. Computational analysis of unmanned aerial vehicle (UAV)

    Abudarag, Sakhr; Yagoub, Rashid; Elfatih, Hassan; Filipovic, Zoran

    2017-01-01

    A computational analysis has been performed to verify the aerodynamics properties of Unmanned Aerial Vehicle (UAV). The UAV-SUST has been designed and fabricated at the Department of Aeronautical Engineering at Sudan University of Science and Technology in order to meet the specifications required for surveillance and reconnaissance mission. It is classified as a medium range and medium endurance UAV. A commercial CFD solver is used to simulate steady and unsteady aerodynamics characteristics of the entire UAV. In addition to Lift Coefficient (CL), Drag Coefficient (CD), Pitching Moment Coefficient (CM) and Yawing Moment Coefficient (CN), the pressure and velocity contours are illustrated. The aerodynamics parameters are represented a very good agreement with the design consideration at angle of attack ranging from zero to 26 degrees. Moreover, the visualization of the velocity field and static pressure contours is indicated a satisfactory agreement with the proposed design. The turbulence is predicted by enhancing K-ω SST turbulence model within the computational fluid dynamics code.

  1. Analysis of airways in computed tomography

    Petersen, Jens

    Chronic Obstructive Pulmonary Disease (COPD) is major cause of death and disability world-wide. It affects lung function through destruction of lung tissue known as emphysema and inflammation of airways, leading to thickened airway walls and narrowed airway lumen. Computed Tomography (CT) imaging...... have become the standard with which to assess emphysema extent but airway abnormalities have so far been more challenging to quantify. Automated methods for analysis are indispensable as the visible airway tree in a CT scan can include several hundreds of individual branches. However, automation...... of scan on airway dimensions in subjects with and without COPD. The results show measured airway dimensions to be affected by differences in the level of inspiration and this dependency is again influenced by COPD. Inspiration level should therefore be accounted for when measuring airways, and airway...

  2. Alpha particle radiography of small insects

    Chingshen Su [National Tsing Hua Univ., Hsinchu (Taiwan) Inst. of Nuclear Science

    1993-12-31

    Radiographies of ants, mosquitoes, cockroaches and small bugs have been done with a radioisotope {sup 244}Cm alpha source. Energy of alpha particles was varied by attenuating the 5.81 MeV alpha particles with adjustable air spacings from the source to the sample. The LR-115 was used to register radiographs. The image of the insect registered on the LR-115 was etched out in a 2.5 N NaOH solution at 52{sup o}C for certain minutes, depending on various irradiation conditions for the insects. For larger insects, a scanning device for the alpha particle irradiation has been fabricated to take the radiograph of whole body of the insect, and the scanning period can be selected to give desired irradiation dosage. A CCDTV camera system connected to a microscope interfaced to an IBM/AT computer is used to register the microscopic image of the radiograph and to print it out with a video copy processor. (Author).

  3. A dose monitoring system for dental radiography

    Lee, Chena; Lee, Sam Sun; Kim, Jo Eun; Huh, Kyung Hoe; Yi, Woo Jin; Heo, Min Suk; Choi, Soon Chul [Dept. of Oral and Maxillofacial Radiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of); Symkhampha, Khanthaly [Dept. of Oral and Maxillofacial Radiology, Department of Basic Science, Faculty of Dentistry, University of Health Sciences, Vientiane (Lao People' s Democratic Republic); Lee, Woo Jin [Dept. of Interdisciplinary Program in Radiation, Applied Life Sciences Major, College of Medicine, BK21, and Dental Research Institute, Seoul National University, Seoul (Korea, Republic of); Yeom, Heon Young [School of Computer Science Engineering, Seoul National University, Seoul (Korea, Republic of)

    2016-06-15

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

  4. Performance Analysis of Cloud Computing Architectures Using Discrete Event Simulation

    Stocker, John C.; Golomb, Andrew M.

    2011-01-01

    Cloud computing offers the economic benefit of on-demand resource allocation to meet changing enterprise computing needs. However, the flexibility of cloud computing is disadvantaged when compared to traditional hosting in providing predictable application and service performance. Cloud computing relies on resource scheduling in a virtualized network-centric server environment, which makes static performance analysis infeasible. We developed a discrete event simulation model to evaluate the overall effectiveness of organizations in executing their workflow in traditional and cloud computing architectures. The two part model framework characterizes both the demand using a probability distribution for each type of service request as well as enterprise computing resource constraints. Our simulations provide quantitative analysis to design and provision computing architectures that maximize overall mission effectiveness. We share our analysis of key resource constraints in cloud computing architectures and findings on the appropriateness of cloud computing in various applications.

  5. Imaging beamline for high energy proton radiography

    WEI Tao; YANG Guo-Jun; LONG Ji-Dong; WANG Shao-Heng; HE Xiao-Zhong

    2012-01-01

    Proton radiography is a new tool for advanced hydrotesting.This article will discuss the basic concept of proton radiography first,especially the magnetic lens system.Then a scenario of 50 GeV imaging beamline will be described in every particular,including the matching section,Zumbro lens system and imaging system.The simulation result shows that the scenario of imaging beamline performs well,and the influence of secondary particles can be neglected.

  6. 衍射增强成像中余弦曲线拟合方法的噪声分析%Noise analysis of cosine fitting radiography for diffraction enhanced imaging

    鲍园; 王研; 朱佩平; 吴自玉

    2015-01-01

    衍射增强成像是一种功能强大的相位衬度成像技术,其信息分离研究一直都是研究热点。提出了一种简便的信息分离方法——余弦曲线拟合法(Cosine Fitting Radiography, CFR),该方法具有简便、样品所受辐射剂量低等优点。利用同步辐射实验和蒙特卡罗仿真方法,从角度信号成像模型出发解释了此方法,同时从噪声传递角度分析了该方法的性能和给出定量的评价指标,建立了衍射增强成像和光栅微分干涉成像之间更直观的联系。对理解衍射增强成像系统的噪声行为和提高信噪比具有一定的参考意义。%Background: Diffraction enhanced imaging (DEI) is a powerful phase contrast imaging technique. Purpose: This study aims to investigate the noise properties of a new simple cosine fitting radiography for DEI based on the angular signal response imaging prototype. Methods: The rocking curve can be treated as a angular signal response and a simple multi-information retrieval algorithm based on the cosine function fitting. A comprehensive analysis of noise properties in DEI, based on a noise model including the fluctuation of the photon source, and a bias of the analyzer crystal are also given. The validations have been performed with Monte Carlo simulations based on the Geant4 toolkit combined with the refractive process of X-ray and synchrotron radiation experimental data. Results: The cosine fitting radiography (CFR) has been verified by Monte Carlo simulations and experimental data which are in good agreement with each other. The noise penalty is drastically reduced with high photon flux, high visibility and high angular precision. Conclusions: Based on the angular signal response function prototype, we analyze and calculate the noise properties of DEI. In addition, the analytical method can build a strong connection between DEI and grating-based phase contrast imaging (GDPCI) and widely suitable for all kinds of

  7. Can cloud computing benefit health services? - a SWOT analysis.

    Kuo, Mu-Hsing; Kushniruk, Andre; Borycki, Elizabeth

    2011-01-01

    In this paper, we discuss cloud computing, the current state of cloud computing in healthcare, and the challenges and opportunities of adopting cloud computing in healthcare. A Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis was used to evaluate the feasibility of adopting this computing model in healthcare. The paper concludes that cloud computing could have huge benefits for healthcare but there are a number of issues that will need to be addressed before its widespread use in healthcare.

  8. A computational design system for rapid CFD analysis

    Ascoli, E. P.; Barson, S. L.; Decroix, M. E.; Sindir, Munir M.

    1992-01-01

    A computation design system (CDS) is described in which these tools are integrated in a modular fashion. This CDS ties together four key areas of computational analysis: description of geometry; grid generation; computational codes; and postprocessing. Integration of improved computational fluid dynamics (CFD) analysis tools through integration with the CDS has made a significant positive impact in the use of CFD for engineering design problems. Complex geometries are now analyzed on a frequent basis and with greater ease.

  9. Simulation of proton radiography terminal at IMP

    Yan, Yan; Huang, Zhi-Wu; Wang, Jie; Yao, Ze-En; Wang, Jun-Run; Wei, Zheng; Yang, Jian-Cheng; Yuan, You-Jin

    2015-01-01

    Proton radiography is used for advanced hydrotesting as a new type radiography technology due to its powerful penetration capability and high detection efficiency. A new proton radiography terminal will be developed to radiograph static samples at Institute of Modern Physics of Chinese Academy of Science (IMP-CAS). The proton beam with the maximum energy of 2.6 GeV will be produced by Heavy Ion Research Facility in Lanzhou-Cooling Storage Ring (HIRFL-CSR). The proton radiography terminal consists of the matching magnetic lens and the Zumbro lens system. In this paper, the design scheme and all optic parameters of this beam terminal for 2.6GeV proton energy are presented by simulating the beam optics using WINAGILE code. My-BOC code is used to test the particle tracking of proton radiography beam line. Geant4 code and G4beamline code are used for simulating the proton radiography system. The results show that the transmission efficiency of proton without target is 100%, and the effect of secondary particles ca...

  10. Schlieren sequence analysis using computer vision

    Smith, Nathanial Timothy

    Computer vision-based methods are proposed for extraction and measurement of flow structures of interest in schlieren video. As schlieren data has increased with faster frame rates, we are faced with thousands of images to analyze. This presents an opportunity to study global flow structures over time that may not be evident from surface measurements. A degree of automation is desirable to extract flow structures and features to give information on their behavior through the sequence. Using an interdisciplinary approach, the analysis of large schlieren data is recast as a computer vision problem. The double-cone schlieren sequence is used as a testbed for the methodology; it is unique in that it contains 5,000 images, complex phenomena, and is feature rich. Oblique structures such as shock waves and shear layers are common in schlieren images. A vision-based methodology is used to provide an estimate of oblique structure angles through the unsteady sequence. The methodology has been applied to a complex flowfield with multiple shocks. A converged detection success rate between 94% and 97% for these structures is obtained. The modified curvature scale space is used to define features at salient points on shock contours. A challenge in developing methods for feature extraction in schlieren images is the reconciliation of existing techniques with features of interest to an aerodynamicist. Domain-specific knowledge of physics must therefore be incorporated into the definition and detection phases. Known location and physically possible structure representations form a knowledge base that provides a unique feature definition and extraction. Model tip location and the motion of a shock intersection across several thousand frames are identified, localized, and tracked. Images are parsed into physically meaningful labels using segmentation. Using this representation, it is shown that in the double-cone flowfield, the dominant unsteady motion is associated with large scale

  11. Upgrading of neutron radiography/tomography facility at research reactor

    Abd El Bar, Waleed; Mongy, Tarek [Atomic Energy Authority, Cairo (Egypt). ETRR-2; Kardjilov, Nikolay [Helmholtz Zentrum Berlin (HZB) for Materials and Energy, Berlin (Germany)

    2014-03-15

    A state-of-the-art neutron tomography imaging system was set up at the neutron radiography beam tube at the Egypt Second Research Reactor (ETRR-2) and was successfully commissioned in 2013. This study presents a set of tomographic experiments that demonstrate a high quality tomographic image formation. A computer technique for data processing and 3D image reconstruction was used to see inside a copy module of an ancient clay article provided by the International Atomic Energy Agency (IAEA). The technique was also able to uncover tomographic imaging details of a mummified fish and provided a high resolution tomographic image of a defective fire valve. (orig.)

  12. A novel type epithermal neutron radiography detecting and imaging system

    Balasko, M; Svab, E; Eoerdoegh, I

    1999-01-01

    The transfer technique is widely used for epithermal neutron radiography (ENR) for making images upon the object to be investigated. We propose to use instead of the photosensitive film a gamma sensitive scintillation screen (NaCe single crystal), that is monitored by a computer controlled low light level TV camera. The exposure time has been reduced to a duration of only a short fraction of that needed for the conventional transfer process. The presented ENR images consist of electronic signals that are handled by an advanced image processing and analyzing program, the Iman 1.4 version, using a task oriented video grabber.

  13. Research in applied mathematics, numerical analysis, and computer science

    1984-01-01

    Research conducted at the Institute for Computer Applications in Science and Engineering (ICASE) in applied mathematics, numerical analysis, and computer science is summarized and abstracts of published reports are presented. The major categories of the ICASE research program are: (1) numerical methods, with particular emphasis on the development and analysis of basic numerical algorithms; (2) control and parameter identification; (3) computational problems in engineering and the physical sciences, particularly fluid dynamics, acoustics, and structural analysis; and (4) computer systems and software, especially vector and parallel computers.

  14. Computational intelligence for big data analysis frontier advances and applications

    Dehuri, Satchidananda; Sanyal, Sugata

    2015-01-01

    The work presented in this book is a combination of theoretical advancements of big data analysis, cloud computing, and their potential applications in scientific computing. The theoretical advancements are supported with illustrative examples and its applications in handling real life problems. The applications are mostly undertaken from real life situations. The book discusses major issues pertaining to big data analysis using computational intelligence techniques and some issues of cloud computing. An elaborate bibliography is provided at the end of each chapter. The material in this book includes concepts, figures, graphs, and tables to guide researchers in the area of big data analysis and cloud computing.

  15. New computing systems, future computing environment, and their implications on structural analysis and design

    Noor, Ahmed K.; Housner, Jerrold M.

    1993-01-01

    Recent advances in computer technology that are likely to impact structural analysis and design of flight vehicles are reviewed. A brief summary is given of the advances in microelectronics, networking technologies, and in the user-interface hardware and software. The major features of new and projected computing systems, including high performance computers, parallel processing machines, and small systems, are described. Advances in programming environments, numerical algorithms, and computational strategies for new computing systems are reviewed. The impact of the advances in computer technology on structural analysis and the design of flight vehicles is described. A scenario for future computing paradigms is presented, and the near-term needs in the computational structures area are outlined.

  16. Marginal Assessment of Crowns by the Aid of Parallel Radiography

    Farnaz Fattahi

    2015-03-01

    Full Text Available Introduction: Marginal adaptation is the most critical item in long-term prognosis of single crowns. This study aimed to assess the marginal quality as well asthe discrepancies in marginal integrity of some PFM single crowns of posterior teeth by employing parallel radiography in Shiraz Dental School, Shiraz, Iran. Methods: In this descriptive study, parallel radiographies were taken from 200 fabricated PFM single crowns of posterior teeth after cementation and before discharging the patient. To calculate the magnification of the images, a metallic sphere with the thickness of 4 mm was placed in the direction of the crown margin on the occlusal surface. Thereafter, the horizontal and vertical space between the crown margins, the margin of preparations and also the vertical space between the crown margin and the bone crest were measured by using digital radiological software. Results: Analysis of data by descriptive statistics revealed that 75.5% and 60% of the cases had more than the acceptable space (50µm in the vertical (130±20µm and horizontal (90±15µm dimensions, respectively. Moreover, 85% of patients were found to have either horizontal or vertical gap. In 77% of cases, the margins of crowns invaded the biologic width in the mesial and 70% in distal surfaces. Conclusion: Parallel radiography can be expedient in the stage of framework try-in to yield some important information that cannot be obtained by routine clinical evaluations and may improve the treatment prognosis

  17. Thorium-uranium fission radiography

    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.

  18. Mobile real time radiography system

    Vigil, J.; Taggart, D.; Betts, S. [Los Alamos National Lab., NM (United States)] [and others

    1997-11-01

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

  19. Computational Analysis of Pharmacokinetic Behavior of Ampicillin

    Mária Ďurišová

    2016-07-01

    Full Text Available orrespondence: Institute of Experimental Pharmacology and Toxicology, Slovak Academy of Sciences, 841 04 Bratislava, Slovak Republic. Phone + 42-1254775928; Fax +421254775928; E-mail: maria.durisova@savba.sk 84 RESEARCH ARTICLE The objective of this study was to perform a computational analysis of the pharmacokinetic behavior of ampicillin, using data from the literature. A method based on the theory of dynamic systems was used for modeling purposes. The method used has been introduced to pharmacokinetics with the aim to contribute to the knowledge base in pharmacokinetics by including the modeling method which enables researchers to develop mathematical models of various pharmacokinetic processes in an identical way, using identical model structures. A few examples of a successful use of the modeling method considered here in pharmacokinetics can be found in full texts articles available free of charge at the website of the author, and in the example given in the this study. The modeling method employed in this study can be used to develop a mathematical model of the pharmacokinetic behavior of any drug, under the condition that the pharmacokinetic behavior of the drug under study can be at least partially approximated using linear models.

  20. Computer assistance in clinical functional analysis.

    Ahlers, M O; Jakstat, H A

    2002-10-01

    The use of computers in the dental practice has been primarily restricted to the acquisition of billing data. Additional possibilities for use of PCs exist in diagnostic data acquisition and evaluation; clinical functional analysis seems a particularly suitable application. Such software is now available: CMDfact. Dentally, it is based on a previously developed and published examination and documentation system, the graphic user interface of which is used in the newly developed software. After the examination data have been acquired by mouse click or numerical entry, these are available for evaluation. A special function, the "Diagnosis pilot" is integrated to support the user. This helps in the assignment of the appropriate "Initial diagnoses", since it brings together the individually existing principal symptoms and suitable diagnoses for the initial diagnosis in question and also states which diagnoses "would be appropriate" for this, but are not available. With 3D animation, the software also helps the dentist to explain aspects of CMD to patients. The software also assists the dentist with a detailed multimedia help system, which provides context-sensitive help for every examination step. These help functions explain the sense of the relevant examinations, their performance and evaluation in the form of short texts and explanatory photographs and videos.

  1. Computational systems analysis of dopamine metabolism.

    Zhen Qi

    Full Text Available A prominent feature of Parkinson's disease (PD is the loss of dopamine in the striatum, and many therapeutic interventions for the disease are aimed at restoring dopamine signaling. Dopamine signaling includes the synthesis, storage, release, and recycling of dopamine in the presynaptic terminal and activation of pre- and post-synaptic receptors and various downstream signaling cascades. As an aid that might facilitate our understanding of dopamine dynamics in the pathogenesis and treatment in PD, we have begun to merge currently available information and expert knowledge regarding presynaptic dopamine homeostasis into a computational model, following the guidelines of biochemical systems theory. After subjecting our model to mathematical diagnosis and analysis, we made direct comparisons between model predictions and experimental observations and found that the model exhibited a high degree of predictive capacity with respect to genetic and pharmacological changes in gene expression or function. Our results suggest potential approaches to restoring the dopamine imbalance and the associated generation of oxidative stress. While the proposed model of dopamine metabolism is preliminary, future extensions and refinements may eventually serve as an in silico platform for prescreening potential therapeutics, identifying immediate side effects, screening for biomarkers, and assessing the impact of risk factors of the disease.

  2. An Analysis of 27 Years of Research into Computer Education Published in Australian Educational Computing

    Zagami, Jason

    2015-01-01

    Analysis of three decades of publications in Australian Educational Computing (AEC) provides insight into the historical trends in Australian educational computing, highlighting an emphasis on pedagogy, comparatively few articles on educational technologies, and strong research topic alignment with similar international journals. Analysis confirms…

  3. Localized Energy-Based Normalization of Medical Images: Application to Chest Radiography.

    Philipsen, R H H M; Maduskar, P; Hogeweg, L; Melendez, J; Sánchez, C I; van Ginneken, B

    2015-09-01

    Automated quantitative analysis systems for medical images often lack the capability to successfully process images from multiple sources. Normalization of such images prior to further analysis is a possible solution to this limitation. This work presents a general method to normalize medical images and thoroughly investigates its effectiveness for chest radiography (CXR). The method starts with an energy decomposition of the image in different bands. Next, each band's localized energy is scaled to a reference value and the image is reconstructed. We investigate iterative and local application of this technique. The normalization is applied iteratively to the lung fields on six datasets from different sources, each comprising 50 normal CXRs and 50 abnormal CXRs. The method is evaluated in three supervised computer-aided detection tasks related to CXR analysis and compared to two reference normalization methods. In the first task, automatic lung segmentation, the average Jaccard overlap significantly increased from 0.72±0.30 and 0.87±0.11 for both reference methods to with normalization. The second experiment was aimed at segmentation of the clavicles. The reference methods had an average Jaccard index of 0.57±0.26 and 0.53±0.26; with normalization this significantly increased to . The third experiment was detection of tuberculosis related abnormalities in the lung fields. The average area under the Receiver Operating Curve increased significantly from 0.72±0.14 and 0.79±0.06 using the reference methods to with normalization. We conclude that the normalization can be successfully applied in chest radiography and makes supervised systems more generally applicable to data from different sources.

  4. Beam Characterization at the Neutron Radiography Facility

    Sarah Morgan; Jeffrey King

    2013-01-01

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

  5. Codesign Analysis of a Computer Graphics Application

    Madsen, Jan; Brage, Jens P.

    1996-01-01

    This paper describes a codesign case study where a computer graphics application is examined with the intention to speed up its execution. The application is specified as a C program, and is characterized by the lack of a simple compute-intensive kernel. The hardware/software partitioning is based...

  6. Dynamic Stall Analysis Utilizing Interactive Computer Graphics

    1988-03-01

    Blade-Vortex Interaction (BV[) studies. solkes the two-dimen i,)nal, unsteady, compressible Euler and Napier -Stokes equations in strong conservation...requirements, interactive computer graphics workstations have been evolved to complement the super -computer. Workstation capabilities, in terms of

  7. Computational Intelligence in Intelligent Data Analysis

    Nürnberger, Andreas

    2013-01-01

    Complex systems and their phenomena are ubiquitous as they can be found in biology, finance, the humanities, management sciences, medicine, physics and similar fields. For many problems in these fields, there are no conventional ways to mathematically or analytically solve them completely at low cost. On the other hand, nature already solved many optimization problems efficiently. Computational intelligence attempts to mimic nature-inspired problem-solving strategies and methods. These strategies can be used to study, model and analyze complex systems such that it becomes feasible to handle them. Key areas of computational intelligence are artificial neural networks, evolutionary computation and fuzzy systems. As only a few researchers in that field, Rudolf Kruse has contributed in many important ways to the understanding, modeling and application of computational intelligence methods. On occasion of his 60th birthday, a collection of original papers of leading researchers in the field of computational intell...

  8. Automatic readout for nuclear emulsions in muon radiography of volcanoes

    Aleksandrov, A.; Bozza, C.; Consiglio, L.; D'Ambrosio, N.; De Lellis, G.; Di Crescenzo, A.; Di Marco, N.; Kose, U.; Lauria, A.; Medinaceli, E.; Miyamoto, S.; Montesi, C.; Pupilli, F.; Rescigno, R.; Russo, A.; Sirignano, C.; Stellacci, S. M.; Strolin, P.; Tioukov, V.

    2012-04-01

    Nuclear emulsions are an effective choice in many scenarios of volcano radiography by cosmic-ray muons. They are cheap and emulsion-based detectors require no on-site power supply. Nuclear emulsion films provide sub-micrometric tracking precision and intrinsic angular accuracy better than 1 mrad. Imaging the inner structure of a volcano requires that the cosmic-ray absorption map be measured on wide angular range. High-absorption directions can be probed by allowing for large statistics, which implies a large overall flux, i.e. wide surface for the detector. A total area of the order of a few m2 is nowadays typical, thanks to the automatic readout tools originally developed for high-energy physics experiments such as CHORUS, PEANUT, OPERA. The European Scanning System is now being used to read out nuclear emulsion films exposed to cosmic rays on the side of volcanoes. The structure of the system is described in detail with respect to both hardware and software. Its present scanning speed of 20 cm2/h/side/microscope is suitable to fulfil the needs of the current exposures of nuclear emulsion films for muon radiograph, but it is worth to notice that applications in volcano imaging are among the driving forces pushing to increase the performances of the system. Preliminary results for the Unzen volcano of a joint effort by research groups in Italy and Japan show that the current system is already able to provide signal/background ratio in the range 100÷10000:1, depending on the quality cuts set in the off-line data analysis. The size of the smallest detectable structures in that experimental setup is constrained by the available statistics in the region of highest absorption to about 50 mrad, or 22 m under the top of the mountain. Another exposure is currently taking data at the Stromboli volcano. Readout of the exposed films is expected to begin in March 2012, and preliminary results will be available soon after. An effort by several universities and INFN has

  9. Fault-Tolerant Postselected Quantum Computation: Threshold Analysis

    Knill, E

    2004-01-01

    The schemes for fault-tolerant postselected quantum computation given in [Knill, Fault-Tolerant Postselected Quantum Computation: Schemes, http://arxiv.org/abs/quant-ph/0402171] are analyzed to determine their error-tolerance. The analysis is based on computer-assisted heuristics. It indicates that if classical and quantum communication delays are negligible, then scalable qubit-based quantum computation is possible with errors above 1% per elementary quantum gate.

  10. Muon radiography for exploration of Mars geology

    S. Kedar

    2013-06-01

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

  11. Muon radiography for exploration of Mars geology

    S. Kedar

    2012-10-01

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

  12. Introduction to numerical analysis and scientific computing

    Nassif, Nabil

    2013-01-01

    Computer Number Systems and Floating Point Arithmetic Introduction Conversion from Base 10 to Base 2Conversion from Base 2 to Base 10Normalized Floating Point SystemsFloating Point OperationsComputing in a Floating Point SystemFinding Roots of Real Single-Valued Functions Introduction How to Locate the Roots of a Function The Bisection Method Newton's Method The Secant MethodSolving Systems of Linear Equations by Gaussian Elimination Mathematical Preliminaries Computer Storage for Matrices. Data Structures Back Substitution for Upper Triangular Systems Gauss Reduction LU DecompositionPolynomia

  13. 锥形束CT 和根尖片诊断根尖区牙根外吸收的比较研究%A comparative study of cone-beam computed tomography and periapical radiography in the diagnosis of external apical root resorption

    董艳玲; 陈军; 邓锋; 郑雷蕾; 任洪芋

    2014-01-01

    Objective To compare the accuracy of cone-beam computed tomography (CBCT ) and periapical radiography in the diagnosis of simulated external apical root resorption (EARR) .Methods The study sample comprised 160 single-rooted premolars for simulating 4 degrees of EARR :no(intact teeth) ,mild(cavity of 1 .0 mm in diameter and depth in root surface) ,moderate(1 .0 mm root shortening) ,and severe(3 .0 mm root shortening) .Two sets of radiographic images were acquired with CBCT and periapi-cal radiography .The severity for all resorption lesions were evaluated blindly by one calibrated examiner .The percentages of correct classification of each degree of EARR were compared between the two imaging techniques using McNemar test .Results With CBCT method ,the percentages of correct classification of no ,mild ,moderate ,severe and all EARR were 95 .0% ,97 .5% ,42 .5% , 87 .5% and 80 .6% ,respectively ;with periapical radiography method ,the percentages were 85 .0% ,42 .5% ,70 .0% ,92 .5% and 72 .5% ,respectively .Significant differences were found between the two imaging techniques for evaluating mild ,moderate ,and all-EARR(P<0 .05) .Conclusion CBCT imaging is more reliable than periapical radiography for detecting EARR ,whereas it is not sensitive to moderate root shortening .In orthodontic practices ,CBCT could be applied to the early diagnosis of EARR ,in order to help make the decision on continuation and modification of orthodontic treatment .%目的:比较锥形束C T (CBC T )和根尖片诊断根尖区牙根外吸收(根尖吸收)的准确性。方法选取160颗单根前磨牙,用以模拟4种不同程度的根尖吸收:无、轻度、中度、重度。模拟完成后,对所有牙齿拍摄CBC T 和根尖片获取两组影像学资料。正畸医师通过对影像学资料的分析独立地评估所有牙齿根尖吸收程度。采用McNemar检验对比分析两种成像技术诊断不同程度根尖吸收的准确率。结果 CBC T 诊断无、轻

  14. Dosimetry and optimization in digital radiography based on the detail contrast resolution

    Gomes B, W. O. [Instituto Federal da Bahia, Rua Emidio dos Santos s/n, Barbalho 40301-015, Salvador de Bahia (Brazil); Gomes de C, A., E-mail: wilsonottobatista@gmail.com [Secretaria de Saude do Estado da Bahia, Salvador de Bahia (Brazil)

    2016-10-15

    In digital radiography, computed radiography systems (CR) and portable panels a-Si (DR) are adapted to equipment previously used for the system screen / film. Therefore it maintains the characteristics as grid, filtration, yield, etc. Otherwise, the systems dedicated with a-Si panels (DR), are designed to operate with these image receptors. The ability to detect in low contrast details is reduced for all systems with increasing ratio of scattered radiation / primary radiation. In this context there is a need to acquire experience and adjust exposure protocols to ensure the quality of the image with maintaining kerma values in the surface as low as possible. The contrast resolution is defined as the ability of the system to distinguish similar degrees of attenuation of the object and is a parameter used to maintain the quality index and comparison between different systems. The protocols were: chest (90 and 102 kV with the range of 2-20 m As) and abdomen (80 kV in the range of 10-80 m As). Kerma values were evaluated with a solid state sensors. Based on analysis of these curves C-D, which identified the technique would imply a lower kerma input surface while maintaining image quality from the point of view of contrast-detail resolution. The results show that the IQFinv varies little throughout the range of m As, while the value of kerma varies linearly with in m As. Also, the complete analysis of the curves indicate that there was an increase in the definition of detail with increasing m As. The conclusion is that, in the transition phase of the new receivers are needed to assess and adjust practiced protocols to ensure the quality index of the image taking into account aspects of radiation protection of the patient. And even with digital technology, good radiographic technique should be practiced. (Author)

  15. Granular computing analysis and design of intelligent systems

    Pedrycz, Witold

    2013-01-01

    Information granules, as encountered in natural language, are implicit in nature. To make them fully operational so they can be effectively used to analyze and design intelligent systems, information granules need to be made explicit. An emerging discipline, granular computing focuses on formalizing information granules and unifying them to create a coherent methodological and developmental environment for intelligent system design and analysis. Granular Computing: Analysis and Design of Intelligent Systems presents the unified principles of granular computing along with its comprehensive algo

  16. Computational Notes on the Numerical Analysis of Galactic Rotation Curves

    Scelza, G

    2014-01-01

    In this paper we present a brief discussion on the salient points of the computational analysis that are at the basis of the paper \\cite{StSc}. The computational and data analysis have been made with the software Mathematica$^\\circledR$ and presented at Mathematica Italia User Group Meeting 2011.

  17. Computer-Assisted Linguistic Analysis of the Peshitta

    Roorda, D.; Talstra, Eep; Dyk, Janet; van Keulen, Percy; Sikkel, Constantijn; Bosman, H.J.; Jenner, K.D.; Bakker, Dirk; Volkmer, J.A.; Gutman, Ariel; van Peursen, Wido Th.

    2014-01-01

    CALAP (Computer-Assisted Linguistic Analysis of the Peshitta), a joint research project of the Peshitta Institute Leiden and the Werkgroep Informatica at the Vrije Universiteit Amsterdam (1999-2005) CALAP concerned the computer-assisted analysis of the Peshitta to Kings (Janet Dyk and Percy van Keul

  18. Behavior computing modeling, analysis, mining and decision

    2012-01-01

    Includes six case studies on behavior applications Presents new techniques for capturing behavior characteristics in social media First dedicated source of references for the theory and applications of behavior informatics and behavior computing

  19. Computer analysis of slow vital capacity spirograms.

    Primiano, F P; Bacevice, A E; Lough, M D; Doershuk, C F

    1982-01-01

    We have developed a digital computer program which evaluates the vital capacity and its subdivisions, expiratory reserve volume and inspiratory capacity. The algorithm examines the multibreath spirogram, a continuous record of quiet breathing interspersed among repeated slow, large volume maneuvers. Quiet breaths are recognized by comparing features of each breath to the respective average and variation of these features for all breaths. A self-scaling, iterative procedure is used to identify those end-tidal points that most likely represent the subject's functional residual capacity. A least-squared error baseline is then fit through these points to partition the vital capacity. Twenty-three spirograms from patients with documented pulmonary disease were independently analyzed by the computer, a pulmonary function technician, and the laboratory supervisor. No practical differences were found among the results. However, the computer's values, in contrast to those of the technician, were reproducible on repeated trials and free of computational and transcriptional errors.

  20. Schottky signal analysis: tune and chromaticity computation

    Chanon, Ondine

    2016-01-01

    Schottky monitors are used to determine important beam parameters in a non-destructive way. The Schottky signal is due to the internal statistical fluctuations of the particles inside the beam. In this report, after explaining the different components of a Schottky signal, an algorithm to compute the betatron tune is presented, followed by some ideas to compute machine chromaticity. The tests have been performed with offline and/or online LHC data.

  1. Thyroid dose distribution in dental radiography

    Bristow, R.G.; Wood, R.E.; Clark, G.M. (Ontario Cancer Institute, Toronto (Canada))

    1989-10-01

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

  2. The Analysis of Some Contemporary Computer Mikrosystems

    Angelė Kaulakienė

    2011-04-01

    Full Text Available In every language a twofold process could be observed: 1 a huge surge of new terms and 2 a big part of these new terms make their way into the common language. The nucleus of the vocabulary and the grammatical system of the common language make the essence of a language and its national originality. Because of such an intensive development in the future terminological lexis can become a basis of a common language and it ought to be not a spontaneously formed sum of terminological lexis, but an entirety of consciously created terms, which meet the requirements of language, logic and terminology. Computer terminology, by comparison with terminology of other fields, is being created in a slightly unusual way. The first computation institutions in Lithuania were established in early sixties and a decade later there were a few computation centres and a number of key-operated and punch machines working. Together with the new computational technology many new devices, units, parts, phenomena and characteristics appeared, which needed naming. Specialists faced an obvious shortage of Lithuanian terms for computing equipment. In 1971 this gap was partly filled by „Rusų-lietuvių-anglų kalbų skaičiavimo technikos žodynas“ (Russian-Lithuanian-English dictionary of computing equipment, which for a long time (for more than 20 years was the only one terminological dictionary of this field. Only during nineties a few dictionaries of different scope appeared. Computer terminology from ten dictionaries, which are presently available, shows that 35 year period of computer terminology is a stage of its creation, the main features of which are reasonable synonymy (when both international term are being used to name the concept and variability. Such state of Lithuanian computer terminology is predetermined by some linguistic, interlinguistic and sociolinguistic factors. At present in Lithuania terminological dictionaries of various fields are being given to

  3. Computational Analysis of LDDMM for Brain Mapping

    Can eCeritoglu

    2013-08-01

    Full Text Available One goal of computational anatomy is to develop tools to accurately segment brain structures in healthy and diseased subjects. In this paper, we examine the performance and complexity of such segmentation in the framework of the large deformation diffeomorphic metric mapping (LDDMM registration method with reference to atlases and parameters. First we report the application of a multi-atlas segmentation approach to define basal ganglia structures in healthy and diseased kids’ brains. The segmentation accuracy of the multi-atlas approach is compared with the single atlas LDDMM implementation and two state-of-the-art segmentation algorithms – Freesurfer and FSL – by computing the overlap errors between automatic and manual segmentations of the six basal ganglia nuclei in healthy subjects as well as subjects with diseases including ADHD and Autism. The high accuracy of multi-atlas segmentation is obtained at the cost of increasing the computational complexity because of the calculations necessary between the atlases and a subject. Second, we examine the effect of parameters on total LDDMM computation time and segmentation accuracy for basal ganglia structures. Single atlas LDDMM method is used to automatically segment the structures in a population of 16 subjects using different sets of parameters. The results show that a cascade approach and using fewer time steps can reduce computational complexity as much as five times while maintaining reliable segmentations.

  4. Development of ionizing radiations dosimetry by plastic detectors and films of radiography; Desenvolvimento de dosimetria de radiacoes ionizantes por detectores plasticos e filmes de radiografia

    Levit, Vladimir; Santos, Ari S.; Louzada, Ana R.; Silveira, Cristina M.; Vaniel, Ana P. [Pelotas Univ., RS (Brazil). Inst. de Quimica e Geociencias]. E-mail: vlevit@ufpel.tche.br; Fedorov, Dmitri [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil)]. E-mail: fedorov@nucleo.inpe.br

    2000-07-01

    This work shows the development of an automatic and computerized system for detection and analysis of the ionizing radiation trace in solid detectors and one of the signals of this irradiation in radiography films with the main goal of improve the ionizing radiation detection methods. On the development of this method it was used a calibration source of {sup 252}Cf, which is a radionuclide with alpha decay and spontaneous fission and, by this reason, irradiates {alpha} and {gamma} particles and nuclear fragments. Solid detectors of makrofol ware used for the nuclear fragments and radiography films ware used for the detection of {alpha} and {gamma} particles. Those signals images reveled of the {alpha} and {gamma} particles and of the nuclear fragments traces ware analysed on a microscopy and recorded on computers. The computer system developed allows to capture those images from the microscope as computer files, the identification of nuclear fragments traces and the {alpha} and {gamma} particles signals and the separation of the objects of interest to do the counting and analysis of the size and the shape of those traces.

  5. Proton Radiography: Its uses and Resolution Scaling

    Mariam, Fesseha G. [Los Alamos National Laboratory

    2012-08-09

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

  6. Adapting computational text analysis to social science (and vice versa

    Paul DiMaggio

    2015-11-01

    Full Text Available Social scientists and computer scientist are divided by small differences in perspective and not by any significant disciplinary divide. In the field of text analysis, several such differences are noted: social scientists often use unsupervised models to explore corpora, whereas many computer scientists employ supervised models to train data; social scientists hold to more conventional causal notions than do most computer scientists, and often favor intense exploitation of existing algorithms, whereas computer scientists focus more on developing new models; and computer scientists tend to trust human judgment more than social scientists do. These differences have implications that potentially can improve the practice of social science.

  7. Cone beam computed tomography aided diagnosis and treatment of endodontic cases: Critical analysis

    Funda Y?lmaz; K?van? Kamburoglu; Naz Yakar Yeta; Meltem Dartar ?ztan

    2016-01-01

    Although intraoral radiographs still remain the imaging method of choice for the evaluation of endodontic patients, in recent years, the utilization of cone beam computed tomography(CBCT) in endodontics showed a significant jump. This case series presentation shows the importance of CBCT aided diagnosis and treatment of complex endodontic cases such as; root resorption, missed extra canal, fusion, oblique root fracture, nondiagnosed periapical pathology and horizontal root fracture. CBCT may be a useful diagnostic method in several endodontic cases where intraoral radiography and clinical examination alone are unable to provide sufficient information.

  8. Cloud Computing for Rigorous Coupled-Wave Analysis

    N. L. Kazanskiy

    2012-01-01

    Full Text Available Design and analysis of complex nanophotonic and nanoelectronic structures require significant computing resources. Cloud computing infrastructure allows distributed parallel applications to achieve greater scalability and fault tolerance. The problems of effective use of high-performance computing systems for modeling and simulation of subwavelength diffraction gratings are considered. Rigorous coupled-wave analysis (RCWA is adapted to cloud computing environment. In order to accomplish this, data flow of the RCWA is analyzed and CPU-intensive operations are converted to data-intensive operations. The generated data sets are structured in accordance with the requirements of MapReduce technology.

  9. Conversation Analysis of Computer-Mediated Communication

    Gonzalez-Lloret, Marta

    2011-01-01

    The potential of computer-mediated communication (CMC) for language learning resides mainly in the possibility that learners have to engage with other speakers of the language, including L1 speakers. The inclusion of CMC in the L2 classroom provides an opportunity for students to utilize authentic language in real interaction, rather than the more…

  10. Computational and Physical Analysis of Catalytic Compounds

    Wu, Richard; Sohn, Jung Jae; Kyung, Richard

    2015-03-01

    Nanoparticles exhibit unique physical and chemical properties depending on their geometrical properties. For this reason, synthesis of nanoparticles with controlled shape and size is important to use their unique properties. Catalyst supports are usually made of high-surface-area porous oxides or carbon nanomaterials. These support materials stabilize metal catalysts against sintering at high reaction temperatures. Many studies have demonstrated large enhancements of catalytic behavior due to the role of the oxide-metal interface. In this paper, the catalyzing ability of supported nano metal oxides, such as silicon oxide and titanium oxide compounds as catalysts have been analyzed using computational chemistry method. Computational programs such as Gamess and Chemcraft has been used in an effort to compute the efficiencies of catalytic compounds, and bonding energy changes during the optimization convergence. The result illustrates how the metal oxides stabilize and the steps that it takes. The graph of the energy computation step(N) versus energy(kcal/mol) curve shows that the energy of the titania converges faster at the 7th iteration calculation, whereas the silica converges at the 9th iteration calculation.

  11. Affect and Learning : a computational analysis

    Broekens, Douwe Joost

    2007-01-01

    In this thesis we have studied the influence of emotion on learning. We have used computational modelling techniques to do so, more specifically, the reinforcement learning paradigm. Emotion is modelled as artificial affect, a measure that denotes the positiveness versus negativeness of a situation

  12. COMPUTING

    M. Kasemann

    Overview During the past three months activities were focused on data operations, testing and re-enforcing shift and operational procedures for data production and transfer, MC production and on user support. Planning of the computing resources in view of the new LHC calendar in ongoing. Two new task forces were created for supporting the integration work: Site Commissioning, which develops tools helping distributed sites to monitor job and data workflows, and Analysis Support, collecting the user experience and feedback during analysis activities and developing tools to increase efficiency. The development plan for DMWM for 2009/2011 was developed at the beginning of the year, based on the requirements from the Physics, Computing and Offline groups (see Offline section). The Computing management meeting at FermiLab on February 19th and 20th was an excellent opportunity discussing the impact and for addressing issues and solutions to the main challenges facing CMS computing. The lack of manpower is particul...

  13. An evaluation of author productivity in international radiography journals 2004–2011

    Snaith, Beverly A [Radiology Department, Mid Yorkshire Hospitals NHS Trust, Pinderfields Hospital, Aberford Road (United Kingdom)

    2013-09-15

    Radiography, the allied health profession, has changed beyond recognition over the last century; however, in academic terms radiography is a relatively young profession. It is therefore still establishing its professional knowledge base. This article uses peer-review author productivity distribution to evaluate its scholarly maturity. Four peer-reviewed journals in medical radiation sciences were examined over an 8-year period (2004–2011) and author productivity was compared to Lotka's law. Further analysis of the most prolific authors provided an evaluation of their characteristics. The 1306 unique authors contributed 835 articles during the study period. Of these, 1012 (77.5%) contributed only one article to the journals studied, with an inverse power relationship of author productivity. At the 0.1 level of significance, radiography does not fit Lotka's law (n = −2.334; c = 0.712; D{sub max} = 0.0627; Critical threshold = 0.0337). There was a significant correlation between the most prolific authors and collaboration (P = 0.002), although variation was noted in author discipline and location. The results of this study add to the discussion of radiography scholarship and demonstrate that the radiography authors have similar productivity distribution to other professions, but do not follow Lotka's law.

  14. Segmental lumbar spine instability at flexion-extension radiography can be predicted by conventional radiography

    Pitkaenen, M.T.; Manninen, H.I.; Lindgren, K.-A.J.; Sihvonen, T.A.; Airaksinen, O.; Soimakallio, S

    2002-07-01

    AIM: To identify plain radiographic findings that predict segmental lumbar spine instability as shown by functional flexion-extension radiography. MATERIALS AND METHODS: Plain radiographs and flexion-extension radiographs of 215 patients with clinically suspected lumbar spine instability were analysed. Instability was classified into anterior or posterior sliding instability. The registered plain radiographic findings were traction spur, spondylarthrosis, arthrosis of facet joints, disc degeneration, retrolisthesis, degenerative spondylolisthesis, spondylolytic spondylolisthesis and vacuum phenomena. Factors reaching statistical significance in univariate analyses (P < 0.05) were included in stepwise multiple logistic regression analysis. RESULTS: Degenerative spondylolisthesis (P = 0.004 at L3-4 level and P = 0.017 at L4-5 level in univariate analysis and odds ratio 16.92 at L4-5 level in multiple logistic regression analyses) and spondylolytic spondylolisthesis (P = 0.003 at L5-S1 level in univariate analyses) were the strongest independent determinants of anterior sliding instability. Retrolisthesis (odds ratio 10.97), traction spur (odds ratio 4.45) and spondylarthrosis (odds ratio 3.20) at L3-4 level were statistically significant determinants of posterior sliding instability in multivariate analysis. CONCLUSION: Sliding instability is strongly associated with various plain radiographic findings. In mechanical back pain, functional flexion-extension radiographs should be limited to situations when symptoms are not explained by findings of plain radiographs and/or when they are likely to alter therapy. Pitkaenen, M.T. et al. (2002)

  15. Spectroscopic neutron radiography for a cargo scanning system

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

    2016-06-01

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

  16. Spectroscopic neutron radiography for a cargo scanning system

    Rahon, Jill [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States); Danagoulian, Areg, E-mail: aregjan@mit.edu [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States); MacDonald, Thomas D. [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States); Hartwig, Zachary S. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States); Lanza, Richard C. [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139 (United States)

    2016-06-01

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

  17. Computational morphology a computational geometric approach to the analysis of form

    Toussaint, GT

    1988-01-01

    Computational Geometry is a new discipline of computer science that deals with the design and analysis of algorithms for solving geometric problems. There are many areas of study in different disciplines which, while being of a geometric nature, have as their main component the extraction of a description of the shape or form of the input data. This notion is more imprecise and subjective than pure geometry. Such fields include cluster analysis in statistics, computer vision and pattern recognition, and the measurement of form and form-change in such areas as stereology and developmental biolo

  18. Computational analysis of ozonation in bubble columns

    Quinones-Bolanos, E. [Univ. of Guelph, School of Engineering, Guelph, Ontario (Canada)]|[Univ. de Cartagena, Facultad de Ciencias e Ingenieria, Cartagena de Indias (Colombia); Zhou, H.; Otten, L. [Univ. of Guelph, School of Engineering, Guelph, Ontario (Canada)]. E-mail: hzhou@uoguelph.ca

    2002-06-15

    This paper presents a new computational ozonation model based on the principle of computational fluid dynamics along with the kinetics of ozone decay and microbial inactivation to predict the performance of ozone disinfection in fine bubble columns. The model can be represented using a mixture two-phase flow model to simulate the hydrodynamics of the water flow and using two transport equations to track the concentration profiles of ozone and microorganisms along the height of the column, respectively. The applicability of this model was then demonstrated by comparing the simulated ozone concentrations with experimental measurements obtained from a pilot scale fine bubble column. One distinct advantage of this approach is that it does not require the prerequisite assumptions such as plug flow condition, perfect mixing, tanks-in-series, uniform radial or longitudinal dispersion in predicting the performance of disinfection contactors without carrying out expensive and tedious tracer studies. (author)

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

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

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

  20. Establishing rigour in qualitative radiography research

    Murphy, F.J. [School of Healthcare Professions, University of Salford, Salford M6 6PU (United Kingdom)], E-mail: f.j.murphy@salford.ac.uk; Yielder, J. [Medical Imaging, School of Health Sciences, Unitec, Auckland (New Zealand)

    2010-02-15

    The vast majority of radiography research is subject to critique and evaluation from peers in order to justify the method and the outcome of the study. Within the quantitative domain, which the majority of medical imaging publications tend to fall into, there are prescribed methods for establishing scientific rigour and quality in order to critique a study. However, researchers within the qualitative paradigm, which is a developing area of radiography research, are often unclear about the most appropriate methods to measure the rigour (standards and quality) of a research study. This article considers the issues related to rigour, reliability and validity within qualitative research. The concepts of reliability and validity are briefly discussed within traditional positivism and then the attempts to use these terms as a measure of quality within qualitative research are explored. Alternative methods for research rigour in interpretive research (meanings and emotions) are suggested in order to compliment the existing radiography framework that exists for qualitative studies. The authors propose the use of an established model that is adapted to reflect the iterative process of qualitative research. Although a mechanistic approach to establishing rigour is rejected by many qualitative researchers, it is argued that a guide for novice researchers within a developing research base such as radiography is appropriate in order to establish the credibility and trustworthiness of a qualitative study.

  1. Conditions for radiation protection in industrial radiography

    1999-01-01

    The leaflet specifies radiation protection requirements for industrial radiography in Norway. The regulations are directed towards companies using or distributing sealed radioactive sources, x-ray equipment or accelerators in non-destructive material testing (NDT). Technical requirements to the equipment, as well as administrative requirements for use, licensing, qualifications, handling of accidents etc. are given. (Author)

  2. Safety Testing of Industrial Radiography Devices

    Trapp, D.J.

    1999-09-29

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

  3. Research Activity in Computational Physics utilizing High Performance Computing: Co-authorship Network Analysis

    Ahn, Sul-Ah; Jung, Youngim

    2016-10-01

    The research activities of the computational physicists utilizing high performance computing are analyzed by bibliometirc approaches. This study aims at providing the computational physicists utilizing high-performance computing and policy planners with useful bibliometric results for an assessment of research activities. In order to achieve this purpose, we carried out a co-authorship network analysis of journal articles to assess the research activities of researchers for high-performance computational physics as a case study. For this study, we used journal articles of the Scopus database from Elsevier covering the time period of 2004-2013. We extracted the author rank in the physics field utilizing high-performance computing by the number of papers published during ten years from 2004. Finally, we drew the co-authorship network for 45 top-authors and their coauthors, and described some features of the co-authorship network in relation to the author rank. Suggestions for further studies are discussed.

  4. Soft computing techniques in voltage security analysis

    Chakraborty, Kabir

    2015-01-01

    This book focuses on soft computing techniques for enhancing voltage security in electrical power networks. Artificial neural networks (ANNs) have been chosen as a soft computing tool, since such networks are eminently suitable for the study of voltage security. The different architectures of the ANNs used in this book are selected on the basis of intelligent criteria rather than by a “brute force” method of trial and error. The fundamental aim of this book is to present a comprehensive treatise on power system security and the simulation of power system security. The core concepts are substantiated by suitable illustrations and computer methods. The book describes analytical aspects of operation and characteristics of power systems from the viewpoint of voltage security. The text is self-contained and thorough. It is intended for senior undergraduate students and postgraduate students in electrical engineering. Practicing engineers, Electrical Control Center (ECC) operators and researchers will also...

  5. Stenosis of calcified carotid artery detected on Panoramic Radiography

    Cho, So Yang; Oh, Won Mann; Yoon, Suk Ja; Yoon, Woong; Lee, Jae Seo; Kang, Byung Cheol [School of Dentistry, Chonnam National University, Seoul (Korea, Republic of); Palomo, Juan M. [Department of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland (United States)

    2009-09-15

    This study aimed to investigate the luminal stenosis of the internal carotid artery with calcification detected on panoramic radiographs. This study used fifty carotid arteries of 36 dental patients whose panoramic radiograph and computed tomography angiography (CTA) revealed the presence of carotid artery calcification. A neuroradiologist interpreted CTA to determine the degree of stenosis of the internal carotid arteries. The degree of stenosis was stratified in four stages; normal (no stenosis), mild stenosis (1-49%), moderate stenosis (50-69%) and severe stenosis (70-99%). Among the fifty carotid arteries with calcification detected on both panoramic radiography and CTA, 20 carotid arteries (40%) were normal, 29 carotid arteries (18%) had mild stenosis, 1 carotid artery (2%) had moderate stenosis, and there was none with severe stenosis. Sixty percent of the carotid arteries with calcification detected on both panoramic radiography and CTA had internal luminal stenosis, and two percent had moderate stenosis. When carotid atheroma is detected on panoramic radiograph, it is possible that the dental patient has luminal stenosis of the internal carotid artery.

  6. Swelling behavior detection of irradiated U-10Zr alloy fuel using indirect neutron radiography

    Sun, Yong; Huo, He-yong; Wu, Yang; Li, Jiangbo; Zhou, Wei; Guo, Hai-bing; Li, Hang; Cao, Chao; Yin, Wei; Wang, Sheng; Liu, Bin; Feng, Qi-jie; Tang, Bin

    2016-11-01

    It is hopeful that fusion-fission hybrid energy system will become an effective approach to achieve long-term sustainable development of fission energy. U-10Zr alloy (which means the mass ratio of Zr is 10%) fuel is the key material of subcritical blanket for fusion-fission hybrid energy system which the irradiation performance need to be considered. Indirect neutron radiography is used to detect the irradiated U-10Zr alloy because of the high residual dose in this paper. Different burnup samples (0.1%, 0.3%, 0.5% and 0.7%) have been tested with a special indirect neutron radiography device at CMRR (China Mianyang Research Reactor). The resolution of the device is better than 50 μm and the quantitative analysis of swelling behaviors was carried out. The results show that the swelling behaviors relate well to burnup character which can be detected accurately by indirect neutron radiography.

  7. Computer-Based Interaction Analysis with DEGREE Revisited

    Barros, B.; Verdejo, M. F.

    2016-01-01

    We review our research with "DEGREE" and analyse how our work has impacted the collaborative learning community since 2000. Our research is framed within the context of computer-based interaction analysis and the development of computer-supported collaborative learning (CSCL) tools. We identify some aspects of our work which have been…

  8. Radiography with cosmic-ray and compact accelerator muons; Exploring inner-structure of large-scale objects and landforms.

    Nagamine, Kanetada

    2016-01-01

    Cosmic-ray muons (CRM) arriving from the sky on the surface of the earth are now known to be used as radiography purposes to explore the inner-structure of large-scale objects and landforms, ranging in thickness from meter to kilometers scale, such as volcanic mountains, blast furnaces, nuclear reactors etc. At the same time, by using muons produced by compact accelerators (CAM), advanced radiography can be realized for objects with a thickness in the sub-millimeter to meter range, with additional exploration capability such as element identification and bio-chemical analysis. In the present report, principles, methods and specific research examples of CRM transmission radiography are summarized after which, principles, methods and perspective views of the future CAM radiography are described.

  9. Computational and experimental analysis of a U-6w/oNb vacuum consumable arc remelted ingot. A progress report for the Sandia macrosegregation study

    Zanner, F. J.; Bertram, L. A.

    1981-04-01

    A computer code (ZAP) has been developed to simulate the thermodynamic, magnetohydrodynamic, and fluid flow conditions in the liquid and solid-liquid regions of a solidifying ingot during vacuum consumable arc remelting. The code is coupled and constrained with experimentally determined measurements of boundary conditions and melt parameters such as melt rate, melt current, and melt time. The work reported presents one preliminary step in the coupled experimental-numerical process. A 538 kg U-6w/oNb ingot was remelted to obtain regions of constant melting current of 2 through 6 kA in 1 kA increments. The melt was simulated numerically using inputs for the code that were obtained from this experiment. Results of this numerical simulation are compared to experimental results obtained from ingot radiography and chemical analysis.

  10. Computational Modeling, Formal Analysis, and Tools for Systems Biology.

    Bartocci, Ezio; Lió, Pietro

    2016-01-01

    As the amount of biological data in the public domain grows, so does the range of modeling and analysis techniques employed in systems biology. In recent years, a number of theoretical computer science developments have enabled modeling methodology to keep pace. The growing interest in systems biology in executable models and their analysis has necessitated the borrowing of terms and methods from computer science, such as formal analysis, model checking, static analysis, and runtime verification. Here, we discuss the most important and exciting computational methods and tools currently available to systems biologists. We believe that a deeper understanding of the concepts and theory highlighted in this review will produce better software practice, improved investigation of complex biological processes, and even new ideas and better feedback into computer science.

  11. Error computation for adaptive finite element analysis

    Khan, A A; Memon, I R; Ming, X Y

    2002-01-01

    The paper gives a simple numerical procedure for computations of errors generated by the discretisation process of finite element method. The procedure given is based on the ZZ error estimator which is believed to be reasonable accurate and thus can be readily implemented in any existing finite element codes. The devised procedure not only estimates the global energy norm error but also evaluates the local errors in individual elements. In the example, the given procedure is combined with an adaptive refinement procedure, which provides guidance for optimal mesh designing and allows the user to obtain a desired accuracy with a limited number of interaction. (author)

  12. Computer-aided Analysis of Phisiological Systems

    Balázs Benyó

    2007-12-01

    Full Text Available This paper presents the recent biomedical engineering research activity of theMedical Informatics Laboratory at the Budapest University of Technology and Economics.The research projects are carried out in the fields as follows: Computer aidedidentification of physiological systems; Diabetic management and blood glucose control;Remote patient monitoring and diagnostic system; Automated system for analyzing cardiacultrasound images; Single-channel hybrid ECG segmentation; Event recognition and stateclassification to detect brain ischemia by means of EEG signal processing; Detection ofbreathing disorders like apnea and hypopnea; Molecular biology studies with DNA-chips;Evaluation of the cry of normal hearing and hard of hearing infants.

  13. Neutron-induced alpha radiography; Radiografia com particulas alfa induzida por neutrons

    Pereira, Marco Antonio Stanojev

    2008-07-01

    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 {alpha} - 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 {mu}m in thickness can be inspected with a spatial resolution of 32 {mu}m. 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 {beta}, {gamma}, X-ray and visible light. (author)

  14. Process for computing geometric perturbations for probabilistic analysis

    Fitch, Simeon H. K. [Charlottesville, VA; Riha, David S [San Antonio, TX; Thacker, Ben H [San Antonio, TX

    2012-04-10

    A method for computing geometric perturbations for probabilistic analysis. The probabilistic analysis is based on finite element modeling, in which uncertainties in the modeled system are represented by changes in the nominal geometry of the model, referred to as "perturbations". These changes are accomplished using displacement vectors, which are computed for each node of a region of interest and are based on mean-value coordinate calculations.

  15. Two computer programs for the analysis of marine magnetic data

    Rao, M.M.M.; Lakshminarayana, S.; Murthy, K.S.R.; Subrahmanyam, A.S.

    stream_size 37575 stream_content_type text/plain stream_name Comput_Geosci_19_657.pdf.txt stream_source_info Comput_Geosci_19_657.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 Computers & Geosciem...'es Vol. 19, No. 5, pp. 657-672, 1993 0098-3004/93 $6.00 + 0.00 Printed in Great Britain. All rights reserved Copyright (' 1993 Pergamon Press Ltd TWO COMPUTER PROGRAMS FOR THE ANALYSIS OF MARINE MAGNETIC DATA M. M. MALLESWARA RAO, S...

  16. COMPUTING

    I. Fisk

    2011-01-01

    Introduction CMS distributed computing system performed well during the 2011 start-up. The events in 2011 have more pile-up and are more complex than last year; this results in longer reconstruction times and harder events to simulate. Significant increases in computing capacity were delivered in April for all computing tiers, and the utilisation and load is close to the planning predictions. All computing centre tiers performed their expected functionalities. Heavy-Ion Programme The CMS Heavy-Ion Programme had a very strong showing at the Quark Matter conference. A large number of analyses were shown. The dedicated heavy-ion reconstruction facility at the Vanderbilt Tier-2 is still involved in some commissioning activities, but is available for processing and analysis. Facilities and Infrastructure Operations Facility and Infrastructure operations have been active with operations and several important deployment tasks. Facilities participated in the testing and deployment of WMAgent and WorkQueue+Request...

  17. COMPUTING

    P. McBride

    The Computing Project is preparing for a busy year where the primary emphasis of the project moves towards steady operations. Following the very successful completion of Computing Software and Analysis challenge, CSA06, last fall, we have reorganized and established four groups in computing area: Commissioning, User Support, Facility/Infrastructure Operations and Data Operations. These groups work closely together with groups from the Offline Project in planning for data processing and operations. Monte Carlo production has continued since CSA06, with about 30M events produced each month to be used for HLT studies and physics validation. Monte Carlo production will continue throughout the year in the preparation of large samples for physics and detector studies ramping to 50 M events/month for CSA07. Commissioning of the full CMS computing system is a major goal for 2007. Site monitoring is an important commissioning component and work is ongoing to devise CMS specific tests to be included in Service Availa...

  18. Generalized two-dimensional (2D) linear system analysis metrics (GMTF, GDQE) for digital radiography systems including the effect of focal spot, magnification, scatter, and detector characteristics

    Kuhls-Gilcrist, Andrew T.; Gupta, Sandesh K.; Bednarek, Daniel R.; Rudin, Stephen

    2010-01-01

    The MTF, NNPS, and DQE are standard linear system metrics used to characterize intrinsic detector performance. To evaluate total system performance for actual clinical conditions, generalized linear system metrics (GMTF, GNNPS and GDQE) that include the effect of the focal spot distribution, scattered radiation, and geometric unsharpness are more meaningful and appropriate. In this study, a two-dimensional (2D) generalized linear system analysis was carried out for a standard flat panel detector (FPD) (194-micron pixel pitch and 600-micron thick CsI) and a newly-developed, high-resolution, micro-angiographic fluoroscope (MAF) (35-micron pixel pitch and 300-micron thick CsI). Realistic clinical parameters and x-ray spectra were used. The 2D detector MTFs were calculated using the new Noise Response method and slanted edge method and 2D focal spot distribution measurements were done using a pin-hole assembly. The scatter fraction, generated for a uniform head equivalent phantom, was measured and the scatter MTF was simulated with a theoretical model. Different magnifications and scatter fractions were used to estimate the 2D GMTF, GNNPS and GDQE for both detectors. Results show spatial non-isotropy for the 2D generalized metrics which provide a quantitative description of the performance of the complete imaging system for both detectors. This generalized analysis demonstrated that the MAF and FPD have similar capabilities at lower spatial frequencies, but that the MAF has superior performance over the FPD at higher frequencies even when considering focal spot blurring and scatter. This 2D generalized performance analysis is a valuable tool to evaluate total system capabilities and to enable optimized design for specific imaging tasks. PMID:21243038

  19. 全景片和锥形束 CT 评价牙根近远中倾斜度的现状和进展%Current situation and progress of evaluating mesiodistal root angulation by panoramic radiography & nbsp;and cone beam computed tomography

    刘太琪; 周力; 王艳民

    2013-01-01

    A fundamental goal in comprehensive orthodontic treatment is the correct angulation of all teeth in three planes of space, and this calls for proper mesiodistal root angulation. Nowadays the main available methods to evaluate mesiodistal root angulation are panoramic radiography and cone beam computed tomography(CBCT). Each one of them has its own benefit and limitation with different efficacy. This article is to review the current situation and progress of these two methods in evaluating mesiodistal root angulation.%  正畸综合治疗的基本目标之一是将牙齿定位于正确的三维空间位置,合适的牙根近远中倾斜度是其要求之一。现有临床评估牙根近远中倾斜度的方法主要有全景片和锥形束CT(CBCT),两者效能不同,各有优缺点。本文就全景片和 CBCT 用于评价牙根近远中倾斜度的现况和进展进行综述。

  20. 曲面体层片与锥形束CT片对正畸治疗后牙根吸收率的比较性研究%Comparison of apical root resorption after orthodontic treatment by using panoramic radiography and cone-beam computed tomography

    赵健慧; 丁云

    2013-01-01

    目的 对比曲面体层片和锥形束CT片检测正畸治疗后牙根吸收率的差异.方法 应用CBCT及曲面体层片分别对30名青少年患者正畸治疗后前牙的牙根吸收状况进行研究,共359颗前牙,其中上切牙120颗,下切牙119颗,尖牙120颗.对两种方法的检测率进行统计学分析.结果 曲面体层片的前牙牙根吸收率为33.7%,CBCT冠状断层面的牙根吸收率为14.5%,CBCT矢状断层面的牙根吸收率为29.5%,二者都与曲面体层片间有统计学差异且CBCT冠状和矢状面牙根吸收率差异也有统计学意义.结论 曲面体层片对正畸治疗后前牙冠状面牙根吸收状况的判断存有较高的假阳性率,早期以及矢状向的牙根吸收只能由CBCT技术反映.CBCT能更加精确地从三维方向上反映牙根的吸收状况.%Objective To compare panoramic radiography (OPT) and cone beam computed tomography (CBCT) in evaluating orthodontically induced anterior apical root resorption. Methods The sample comprised 359 anterior teeth in 30 adolescent patients after orthodontic treatment with fixed appliances. Two calibrated examiners assessed anterior apical root resorption on the OPT images and the corresponding reconstructed CBCT imagines. Resorption was evaluated according to Levander and Malmgren method. Results Statistically significant differences were found between the OPT and CBCT methods. 33.7%, 14.5% and 29.5% of root resorption were found by OPT, CBCT coronal section and CBCT sagittal section respectively. Conclusion Apical root resorption after orthodontic treatment is overestimated by OPT. Early and slanted root resorption can only be evaluated by CBCT. CBCT is a useful diagnostic method compared with conventional radiography.

  1. Batch Computed Tomography Analysis of Projectiles

    2016-05-01

    resolution. 2.2 CT Image Analysis An algorithm was developed in Matlab † that performed image analysis on each individual cross-sectional image of the...be obtained with a minimum number of descriptor parameters, effectively reducing † Matlab (matrix...single core of an Intel Xeon X5650 processor operating at 2.67 GHz. To batch process the (210) projectiles, a Matlab script was written to parallelize

  2. Development of Computer Science Disciplines - A Social Network Analysis Approach

    Pham, Manh Cuong; Jarke, Matthias

    2011-01-01

    In contrast to many other scientific disciplines, computer science considers conference publications. Conferences have the advantage of providing fast publication of papers and of bringing researchers together to present and discuss the paper with peers. Previous work on knowledge mapping focused on the map of all sciences or a particular domain based on ISI published JCR (Journal Citation Report). Although this data covers most of important journals, it lacks computer science conference and workshop proceedings. That results in an imprecise and incomplete analysis of the computer science knowledge. This paper presents an analysis on the computer science knowledge network constructed from all types of publications, aiming at providing a complete view of computer science research. Based on the combination of two important digital libraries (DBLP and CiteSeerX), we study the knowledge network created at journal/conference level using citation linkage, to identify the development of sub-disciplines. We investiga...

  3. Classification and Analysis of Computer Network Traffic

    Bujlow, Tomasz

    2014-01-01

    various classification modes (decision trees, rulesets, boosting, softening thresholds) regarding the classification accuracy and the time required to create the classifier. We showed how to use our VBS tool to obtain per-flow, per-application, and per-content statistics of traffic in computer networks...... classification (as by using transport layer port numbers, Deep Packet Inspection (DPI), statistical classification) and assessed their usefulness in particular areas. We found that the classification techniques based on port numbers are not accurate anymore as most applications use dynamic port numbers, while...... DPI is relatively slow, requires a lot of processing power, and causes a lot of privacy concerns. Statistical classifiers based on Machine Learning Algorithms (MLAs) were shown to be fast and accurate. At the same time, they do not consume a lot of resources and do not cause privacy concerns. However...

  4. COMPUTER DATA ANALYSIS AND MODELING: COMPLEX STOCHASTIC DATA AND SYSTEMS

    2010-01-01

    This collection of papers includes proceedings of the Ninth International Conference “Computer Data Analysis and Modeling: Complex Stochastic Data and Systems” organized by the Belarusian State University and held in September 2010 in Minsk. The papers are devoted to the topical problems: robust and nonparametric data analysis; statistical analysis of time series and forecasting; multivariate data analysis; design of experiments; statistical signal and image processing...

  5. Solid-state, flat-panel, digital radiography detectors and their physical imaging characteristics.

    Cowen, A R; Kengyelics, S M; Davies, A G

    2008-05-01

    Solid-state, digital radiography (DR) detectors, designed specifically for standard projection radiography, emerged just before the turn of the millennium. This new generation of digital image detector comprises a thin layer of x-ray absorptive material combined with an electronic active matrix array fabricated in a thin film of hydrogenated amorphous silicon (a-Si:H). DR detectors can offer both efficient (low-dose) x-ray image acquisition plus on-line readout of the latent image as electronic data. To date, solid-state, flat-panel, DR detectors have come in two principal designs, the indirect-conversion (x-ray scintillator-based) and the direct-conversion (x-ray photoconductor-based) types. This review describes the underlying principles and enabling technologies exploited by these designs of detector, and evaluates their physical imaging characteristics, comparing performance both against each other and computed radiography (CR). In standard projection radiography indirect conversion DR detectors currently offer superior physical image quality and dose efficiency compared with direct conversion DR and modern point-scan CR. These conclusions have been confirmed in the findings of clinical evaluations of DR detectors. Future trends in solid-state DR detector technologies are also briefly considered. Salient innovations include WiFi-enabled, portable DR detectors, improvements in x-ray absorber layers and developments in alternative electronic media to a-Si:H.

  6. Local spatial frequency analysis for computer vision

    Krumm, John; Shafer, Steven A.

    1990-01-01

    A sense of vision is a prerequisite for a robot to function in an unstructured environment. However, real-world scenes contain many interacting phenomena that lead to complex images which are difficult to interpret automatically. Typical computer vision research proceeds by analyzing various effects in isolation (e.g., shading, texture, stereo, defocus), usually on images devoid of realistic complicating factors. This leads to specialized algorithms which fail on real-world images. Part of this failure is due to the dichotomy of useful representations for these phenomena. Some effects are best described in the spatial domain, while others are more naturally expressed in frequency. In order to resolve this dichotomy, we present the combined space/frequency representation which, for each point in an image, shows the spatial frequencies at that point. Within this common representation, we develop a set of simple, natural theories describing phenomena such as texture, shape, aliasing and lens parameters. We show these theories lead to algorithms for shape from texture and for dealiasing image data. The space/frequency representation should be a key aid in untangling the complex interaction of phenomena in images, allowing automatic understanding of real-world scenes.

  7. Acoustic analysis of a computer cooling fan

    Huang, Lixi; Wang, Jian

    2005-10-01

    Noise radiated by a typical computer cooling fan is investigated experimentally and analyzed within the framework of rotor-stator interaction noise using point source formulation. The fan is 9 cm in rotor casing diameter and its design speed is 3000 rpm. The main noise sources are found and quantified; they are (a) the inlet flow distortion caused by the sharp edges of the incomplete bellmouth due to the square outer framework, (b) the interaction of rotor blades with the downstream struts which hold the motor, and (c) the extra size of one strut carrying electrical wiring. Methods are devised to extract the rotor-strut interaction noise, (b) and (c), radiated by the component forces of drag and thrust at the leading and higher order spinning pressure modes, as well as the leading edge noise generated by (a). By re-installing the original fan rotor in various casings, the noises radiated by the three features of the original fan are separated, and details of the directivity are interpreted. It is found that the inlet flow distortion and the unequal set of four struts make about the same amount of noise. Their corrections show a potential of around 10-dB sound power reduction.

  8. Computational Analysis of Safety Injection Tank Performance

    Cho, Jai Oan; Nietiadia, Yohanes Setiawan; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of); Addad, Yacine; Yoon, Ho Joon [Khalifa University of Science Technology and Research, Abu Dhabi (United Arab Emirates)

    2015-10-15

    The APR 1400 is a large pressurized water reactor (PWR). Just like many other water reactors, it has an emergency core cooling system (ECCS). One of the most important components in the ECCS is the safety injection tank (SIT). Inside the SIT, a fluidic device is installed, which passively controls the mass flow of the safety injection and eliminates the need for low pressure safety injection pumps. As more passive safety mechanisms are being pursued, it has become more important to understand flow structure and the loss mechanism within the fluidic device. Current computational fluid dynamics (CFD) calculations have had limited success in predicting the fluid flow accurately. This study proposes to find a more exact result using CFD and more realistic modeling. The SIT of APR1400 was analyzed using MARS and CFD. CFD calculation was executed first to obtain the form loss factor. Using the two form loss factors from the vendor and calculation, calculation using MARS was performed to compare with experiment. The accumulator model in MARS was quite accurate in predicting the water level. The pipe model showed some difference with the experimental data in the water level.

  9. Computer software for process hazards analysis.

    Hyatt, N

    2000-10-01

    Computerized software tools are assuming major significance in conducting HAZOPs. This is because they have the potential to offer better online presentations and performance to HAZOP teams, as well as better documentation and downstream tracking. The chances of something being "missed" are greatly reduced. We know, only too well, that HAZOP sessions can be like the industrial equivalent of a trip to the dentist. Sessions can (and usually do) become arduous and painstaking. To make the process easier for all those involved, we need all the help computerized software can provide. In this paper I have outlined the challenges addressed in the production of Windows software for performing HAZOP and other forms of PHA. The object is to produce more "intelligent", more user-friendly software for performing HAZOP where technical interaction between team members is of key significance. HAZOP techniques, having already proven themselves, are extending into the field of computer control and human error. This makes further demands on HAZOP software and emphasizes its importance.

  10. Analysis of computational vulnerabilities in digital repositories

    Valdete Fernandes Belarmino

    2015-04-01

    Full Text Available Objective. Demonstrates the results of research that aimed to analyze the computational vulnerabilities of digital directories in public Universities. Argues the relevance of information in contemporary societies like an invaluable resource, emphasizing scientific information as an essential element to constitute scientific progress. Characterizes the emergence of Digital Repositories and highlights its use in academic environment to preserve, promote, disseminate and encourage the scientific production. Describes the main software for the construction of digital repositories. Method. The investigation identified and analyzed the vulnerabilities that are exposed the digital repositories using Penetration Testing running. Discriminating the levels of risk and the types of vulnerabilities. Results. From a sample of 30 repositories, we could examine 20, identified that: 5% of the repositories have critical vulnerabilities, 85% high, 25% medium and 100% lowers. Conclusions. Which demonstrates the necessity to adapt actions for these environments that promote informational security to minimizing the incidence of external and / or internal systems attacks.Abstract Grey Text – use bold for subheadings when needed.

  11. Quantitative shadowgraphy and proton radiography for large intensity modulations

    Kasim, Muhammad Firmansyah; Ratan, Naren; Sadler, James; Chen, Nicholas; Savert, Alexander; Trines, Raoul; Bingham, Robert; Burrows, Philip N; Kaluza, Malte C; Norreys, Peter

    2016-01-01

    Shadowgraphy is a technique widely used to diagnose objects or systems in various fields in physics and engineering. In shadowgraphy, an optical beam is deflected by the object and then the intensity modulation is captured on a screen placed some distance away. However, retrieving quantitative information from the shadowgrams themselves is a challenging task because of the non-linear nature of the process. Here, a novel method to retrieve quantitative information from shadowgrams, based on computational geometry, is presented for the first time. This process can be applied to proton radiography for electric and magnetic field diagnosis in high-energy-density plasmas and has been benchmarked using a toroidal magnetic field as the object, among others. It is shown that the method can accurately retrieve quantitative parameters with error bars less than 10%, even when caustics are present. The method is also shown to be robust enough to process real experimental results with simple pre- and post-processing techn...

  12. Diagnostic radiography of the shoulder. Die Roentgendiagnostik des Schulterguertels

    Opitz, G.; Rechl, H. (Klinikum rechts der Isar, Muenchen (Germany, F.R.). Orthopaedische Klinik und Poliklinik); Lehner, K. (Klinikum rechts der Isar, Muenchen (Germany, F.R.). Inst. fuer Roentgendiagnostik)

    1989-06-01

    The frequent complaint about 'pain in the shoulder' is so diffuse that it needs exact clinical and differentiated radiographic examination. The diagnosis 'periarthritis humeroscapularis' can only be given after exclusion of ossous, chondral, or capsular lesions, joint disorders, rotator cuff rupture, or constriction of the subacromial space. Subsequent to antero-posterior and axial, sometimes also tangential, radiography, sonographic examination in many cases already yields the significant information. In case of suspected rotator cuff rupture, the diagnosis can be verified by arthrography or NMR imaging, and labrum defects can well be detected by computed arthro-tomography or NMR imaging. Although sometimes laborious, diagnostic radiology yields the information required to select the suitable conservative or surgical treatment. (orig.).

  13. Scattering Correction For Image Reconstruction In Flash Radiography

    Cao, Liangzhi; Wang, Mengqi; Wu, Hongchun; Liu, Zhouyu; Cheng, Yuxiong; Zhang, Hongbo [Xi' an Jiaotong Univ., Xi' an (China)

    2013-08-15

    Scattered photons cause blurring and distortions in flash radiography, reducing the accuracy of image reconstruction significantly. The effect of the scattered photons is taken into account and an iterative deduction of the scattered photons is proposed to amend the scattering effect for image restoration. In order to deduct the scattering contribution, the flux of scattered photons is estimated as the sum of two components. The single scattered component is calculated accurately together with the uncollided flux along the characteristic ray, while the multiple scattered component is evaluated using correction coefficients pre-obtained from Monte Carlo simulations.The arbitrary geometry pretreatment and ray tracing are carried out based on the customization of AutoCAD. With the above model, an Iterative Procedure for image restORation code, IPOR, is developed. Numerical results demonstrate that the IPOR code is much more accurate than the direct reconstruction solution without scattering correction and it has a very high computational efficiency.

  14. Computational Understanding: Analysis of Sentences and Context

    1974-05-01

    to take English texts, disambxguate the words and semantic relationships in- volved, and settle questions like anaphoric reference, to the point...rather than what the word in isolation might mean. Tfit theory of text analysis ?.l*o stresses binding by predictions. To assume that a word is...cluster is basically the bundle of predictions and structures, knowledge that can bind a ’.ext into a unit. The cluster has much the same theoretical

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

    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)

  16. AVES: A Computer Cluster System approach for INTEGRAL Scientific Analysis

    Federici, M.; Martino, B. L.; Natalucci, L.; Umbertini, P.

    The AVES computing system, based on an "Cluster" architecture is a fully integrated, low cost computing facility dedicated to the archiving and analysis of the INTEGRAL data. AVES is a modular system that uses the software resource manager (SLURM) and allows almost unlimited expandibility (65,536 nodes and hundreds of thousands of processors); actually is composed by 30 Personal Computers with Quad-Cores CPU able to reach the computing power of 300 Giga Flops (300x10{9} Floating point Operations Per Second), with 120 GB of RAM and 7.5 Tera Bytes (TB) of storage memory in UFS configuration plus 6 TB for users area. AVES was designed and built to solve growing problems raised from the analysis of the large data amount accumulated by the INTEGRAL mission (actually about 9 TB) and due to increase every year. The used analysis software is the OSA package, distributed by the ISDC in Geneva. This is a very complex package consisting of dozens of programs that can not be converted to parallel computing. To overcome this limitation we developed a series of programs to distribute the workload analysis on the various nodes making AVES automatically divide the analysis in N jobs sent to N cores. This solution thus produces a result similar to that obtained by the parallel computing configuration. In support of this we have developed tools that allow a flexible use of the scientific software and quality control of on-line data storing. The AVES software package is constituted by about 50 specific programs. Thus the whole computing time, compared to that provided by a Personal Computer with single processor, has been enhanced up to a factor 70.

  17. Conference “Computational Analysis and Optimization” (CAO 2011)

    Tiihonen, Timo; Tuovinen, Tero; Numerical Methods for Differential Equations, Optimization, and Technological Problems : Dedicated to Professor P. Neittaanmäki on His 60th Birthday

    2013-01-01

    This book contains the results in numerical analysis and optimization presented at the ECCOMAS thematic conference “Computational Analysis and Optimization” (CAO 2011) held in Jyväskylä, Finland, June 9–11, 2011. Both the conference and this volume are dedicated to Professor Pekka Neittaanmäki on the occasion of his sixtieth birthday. It consists of five parts that are closely related to his scientific activities and interests: Numerical Methods for Nonlinear Problems; Reliable Methods for Computer Simulation; Analysis of Noised and Uncertain Data; Optimization Methods; Mathematical Models Generated by Modern Technological Problems. The book also includes a short biography of Professor Neittaanmäki.

  18. Manufacturing details by Neutron Radiography of Archaeological Pottery

    Bernedo, Alfredo Victor Bellido; Latini, Rose Mary [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Souza, Maria Ines Silvani; Vinagre Filho, Ubirajara Maribondo [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Full text: The aim of the present work was to investigate manufacturing details of archaeological pot-sherds ceramics by Neutron Radiography. Pottery is perhaps the most important artefact found in excavation. Its archaeological importance relies on the fact that it can reveal cultural traditions and commercial influences in ancient communities. These pottery was recently discovered in archaeological earth circular structures sites in Acre state Brazil and the characteristics of clay used in their manufacture have been studied by modern scientific techniques such as Instrumental Neutron Activation Analysis (INAA), Thermoluminescence Dating and Moessbauer Spectroscopy. Different fragments of pottery were submitted to a neutron flux of the order of 10{sup 5}n.cm{sup -2}2:s{sup -1} for 3 minutes in the research reactor Argonauta at the Instituto de Engenharia Nuclear/CNEN. Digital processing techniques using imaging plate were applied to the image of the selected sample. The Neutrongraphy shows two different manufacturing details: palette and rollers. The fragment made by the technique of palette show a homogeneous mass and the neutrongraphy of ceramic fragments made by the technique of the rollers, pottery funeral, can be seen horizontal traces of the junction of rollers, overlapping, forming layers supported on each other. This technique allows you to create more stable structures. Thus, both the technique of the pallet as the roller can be characterized by Neutron Radiography. (author)

  19. Reliability of panoramic radiography in chronological age estimation

    Ramanpal Singh Makkad

    2013-01-01

    Full Text Available Introduction: There has been a strong relationship between the growth rate of bone and teeth, which can be utilized for the purpose of age identification of an individual. Aims and Objective: The present study was designed to determine the relationship between the dental age, the age from dental panoramic radiography, skeletal age, and chronological age. Materials and Methods: The study included 270 individuals, averaging between 17 years and 25 years of age from out-patient department of New Horizon Dental College and Hospital, Sakri, Bilaspur, Chhattisgarh, India, for third molar surgery. Panoramic and hand wrist radiographs were taken, the films were digitally processed for visualization of the wisdom teeth. The confirmations of ages were repeated again at an interval of 4 weeks by a radiologist. The extracted wisdom teeth were placed in 10% formalin and were examined by one dental surgeon to estimate the age on the basis of root formation. Student′s t-test was adopted for statistical analysis and probability (P value was calculated. Conclusion: Estimating the age of an individual was accurate by examining extracted third molar. Age estimation through panoramic radiography was highly accurate in upper right quadrant (mean = 0.72 and P = 0.077.

  20. Real-Time Neutron Radiography at CARR

    HE; Lin-feng; HAN; Song-bai; WANG; Hong-li; WU; Mei-mei; WEI; Guo-hai; WANG; Yu

    2012-01-01

    <正>A real-time detector system for neutron radiography based on CMOS camera has been designed for the thermal neutron imaging facility under construction at China Advanced Research Reactor (CARR). This system is equipped with a new scientific CMOS camera with 5.5 million pixels and speed up to 100 fps at full frame. The readout noise is less than 2.4 electron per pixel. It is capable of providing

  1. Assessment of cold neutron radiography capability

    McDonald, T.E. Jr.; Roberts, J.A.

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The authors goals were to demonstrate and assess cold neutron radiography techniques at the Los Alamos Neutron Science Center (LANSCE), Manual Lujan Neutron Scattering Center (Lujan Center), and to investigate potential applications of the capability. The authors have obtained images using film and an amorphous silicon detector. In addition, a new technique they have developed allows neutron radiographs to be made using only a narrow range of neutron energies. Employing this approach and the Bragg cut-off phenomena in certain materials, they have demonstrated material discrimination in radiography. They also demonstrated the imaging of cracks in a sample of a fire-set case that was supplied by Sandia National Laboratory, and they investigated whether the capability could be used to determine the extent of coking in jet engine nozzles. The LANSCE neutron radiography capability appears to have applications in the DOE stockpile maintenance and science-based stockpile stewardship (SBSS) programs, and in industry.

  2. Fifty years of computer analysis in chest imaging: rule-based, machine learning, deep learning.

    van Ginneken, Bram

    2017-03-01

    Half a century ago, the term "computer-aided diagnosis" (CAD) was introduced in the scientific literature. Pulmonary imaging, with chest radiography and computed tomography, has always been one of the focus areas in this field. In this study, I describe how machine learning became the dominant technology for tackling CAD in the lungs, generally producing better results than do classical rule-based approaches, and how the field is now rapidly changing: in the last few years, we have seen how even better results can be obtained with deep learning. The key differences among rule-based processing, machine learning, and deep learning are summarized and illustrated for various applications of CAD in the chest.

  3. Computer-Aided Qualitative Data Analysis with Word

    Bruno Nideröst

    2002-05-01

    Full Text Available Despite some fragmentary references in the literature about qualitative methods, it is fairly unknown that Word can be successfully used for computer-aided Qualitative Data Analyses (QDA. Based on several Word standard operations, elementary QDA functions such as sorting data, code-and-retrieve and frequency counts can be realized. Word is particularly interesting for those users who wish to have first experiences with computer-aided analysis before investing time and money in a specialized QDA Program. The well-known standard software could also be an option for those qualitative researchers who usually work with word processing but have certain reservations towards computer-aided analysis. The following article deals with the most important requirements and options of Word for computer-aided QDA. URN: urn:nbn:de:0114-fqs0202225

  4. A computer analysis of the Schreber Memoirs.

    Klein, R H

    1976-06-01

    With the aid of a computerized system for content analysis, WORDS, the complete Schreber Memoirs was subjected to various multivariate reduction techniques in order to investigate the major content themes of this document. The findings included the prevalence of somatic concerns throughout the Memoirs, clear references to persecutory ideas and to Schreber's assumption of a redemptive role, complex encapsulated concerns about Schreber's relationship with God, a lack of any close relationship between sexuality and sexual transformation either to themes of castration or procreation, and the fact that neither sun, God, nor Flechsig was significantly associated with clusters concerning gender, sexuality, or castration. These findings are discussed in relation to psychodynamic interpretations furnished by prior investigators who employed different research methods.

  5. A Computational Discriminability Analysis on Twin Fingerprints

    Liu, Yu; Srihari, Sargur N.

    Sharing similar genetic traits makes the investigation of twins an important study in forensics and biometrics. Fingerprints are one of the most commonly found types of forensic evidence. The similarity between twins’ prints is critical establish to the reliability of fingerprint identification. We present a quantitative analysis of the discriminability of twin fingerprints on a new data set (227 pairs of identical twins and fraternal twins) recently collected from a twin population using both level 1 and level 2 features. Although the patterns of minutiae among twins are more similar than in the general population, the similarity of fingerprints of twins is significantly different from that between genuine prints of the same finger. Twins fingerprints are discriminable with a 1.5%~1.7% higher EER than non-twins. And identical twins can be distinguished by examine fingerprint with a slightly higher error rate than fraternal twins.

  6. Computational Aspects of Dam Risk Analysis: Findings and Challenges

    Ignacio Escuder-Bueno

    2016-09-01

    Full Text Available In recent years, risk analysis techniques have proved to be a useful tool to inform dam safety management. This paper summarizes the outcomes of three themes related to dam risk analysis discussed in the Benchmark Workshops organized by the International Commission on Large Dams Technical Committee on “Computational Aspects of Analysis and Design of Dams.” In the 2011 Benchmark Workshop, estimation of the probability of failure of a gravity dam for the sliding failure mode was discussed. Next, in 2013, the discussion focused on the computational challenges of the estimation of consequences in dam risk analysis. Finally, in 2015, the probability of sliding and overtopping in an embankment was analyzed. These Benchmark Workshops have allowed a complete review of numerical aspects for dam risk analysis, showing that risk analysis methods are a very useful tool to analyze the risk of dam systems, including downstream consequence assessments and the uncertainty of structural models.

  7. Bacteriological research for the contamination of equipment in chest radiography

    Choi, Seung Gu; Song, Woon Heung; Kweon, Dae Cheol [Shinhan University, Uijeongbu (Korea, Republic of)

    2015-12-15

    The purpose is to determine the degree of contamination of the equipment for infection control in chest radiography of the radiology department. We confirmed by chemical and bacterial identification of bacteria of the equipment and established a preventive maintenance plan. Chest X-ray radiography contact area on the instrument patients shoulder, hand, chin, chest lateral radiography patient contact areas with a 70% isopropyl alcohol cotton swab were compared to identify the bacteria before and after sterilization on the patient contact area in the chest radiography equipment of the department. The gram positive Staphylococcus was isolated from side shoots handle before disinfection in the chest radiography equipment. For the final identification of antibiotic tested that it was determined by performing the nobobiocin to the sensitive Staphylococcus epidermidis. Chest radiography equipment before disinfecting the handle side of Staphylococcus epidermidis bacteria were detected using a disinfectant should be to prevent hospital infections.

  8. COMPUTING

    I. Fisk

    2013-01-01

    Computing activity had ramped down after the completion of the reprocessing of the 2012 data and parked data, but is increasing with new simulation samples for analysis and upgrade studies. Much of the Computing effort is currently involved in activities to improve the computing system in preparation for 2015. Operations Office Since the beginning of 2013, the Computing Operations team successfully re-processed the 2012 data in record time, not only by using opportunistic resources like the San Diego Supercomputer Center which was accessible, to re-process the primary datasets HTMHT and MultiJet in Run2012D much earlier than planned. The Heavy-Ion data-taking period was successfully concluded in February collecting almost 500 T. Figure 3: Number of events per month (data) In LS1, our emphasis is to increase efficiency and flexibility of the infrastructure and operation. Computing Operations is working on separating disk and tape at the Tier-1 sites and the full implementation of the xrootd federation ...

  9. COMPUTING

    I. Fisk

    2010-01-01

    Introduction It has been a very active quarter in Computing with interesting progress in all areas. The activity level at the computing facilities, driven by both organised processing from data operations and user analysis, has been steadily increasing. The large-scale production of simulated events that has been progressing throughout the fall is wrapping-up and reprocessing with pile-up will continue. A large reprocessing of all the proton-proton data has just been released and another will follow shortly. The number of analysis jobs by users each day, that was already hitting the computing model expectations at the time of ICHEP, is now 33% higher. We are expecting a busy holiday break to ensure samples are ready in time for the winter conferences. Heavy Ion An activity that is still in progress is computing for the heavy-ion program. The heavy-ion events are collected without zero suppression, so the event size is much large at roughly 11 MB per event of RAW. The central collisions are more complex and...

  10. Computer programs for analysis of geophysical data

    Rozhkov, M.; Nakanishi, K.

    1994-06-01

    This project is oriented toward the application of the mobile seismic array data analysis technique in seismic investigations of the Earth (the noise-array method). The technique falls into the class of emission tomography methods but, in contrast to classic tomography, 3-D images of the microseismic activity of the media are obtained by passive seismic antenna scanning of the half-space, rather than by solution of the inverse Radon`s problem. It is reasonable to expect that areas of geothermal activity, active faults, areas of volcanic tremors and hydrocarbon deposits act as sources of intense internal microseismic activity or as effective sources for scattered (secondary) waves. The conventional approaches of seismic investigations of a geological medium include measurements of time-limited determinate signals from artificial or natural sources. However, the continuous seismic oscillations, like endogenous microseisms, coda and scattering waves, can give very important information about the structure of the Earth. The presence of microseismic sources or inhomogeneities within the Earth results in the appearance of coherent seismic components in a stochastic wave field recorded on the surface by a seismic array. By careful processing of seismic array data, these coherent components can be used to develop a 3-D model of the microseismic activity of the media or images of the noisy objects. Thus, in contrast to classic seismology where narrow windows are used to get the best time resolution of seismic signals, our model requires long record length for the best spatial resolution.

  11. Numeric computation and statistical data analysis on the Java platform

    Chekanov, Sergei V

    2016-01-01

    Numerical computation, knowledge discovery and statistical data analysis integrated with powerful 2D and 3D graphics for visualization are the key topics of this book. The Python code examples powered by the Java platform can easily be transformed to other programming languages, such as Java, Groovy, Ruby and BeanShell. This book equips the reader with a computational platform which, unlike other statistical programs, is not limited by a single programming language. The author focuses on practical programming aspects and covers a broad range of topics, from basic introduction to the Python language on the Java platform (Jython), to descriptive statistics, symbolic calculations, neural networks, non-linear regression analysis and many other data-mining topics. He discusses how to find regularities in real-world data, how to classify data, and how to process data for knowledge discoveries. The code snippets are so short that they easily fit into single pages. Numeric Computation and Statistical Data Analysis ...

  12. Parallel computation of seismic analysis of high arch dam

    Chen Houqun; Ma Huaifa; Tu Jin; Cheng Guangqing; Tang Juzhen

    2008-01-01

    Parallel computation programs are developed for three-dimensional meso-mechanics analysis of fully-graded dam concrete and seismic response analysis of high arch dams (ADs), based on the Parallel Finite Element Program Generator (PFEPG). The computational algorithms of the numerical simulation of the meso-structure of concrete specimens were studied. Taking into account damage evolution, static preload, strain rate effect, and the heterogeneity of the meso-structure of dam concrete, the fracture processes of damage evolution and configuration of the cracks can be directly simulated. In the seismic response analysis of ADs, all the following factors are involved, such as the nonlinear contact due to the opening and slipping of the contraction joints, energy dispersion of the far-field foundation, dynamic interactions of the dam-foundation-reservoir system, and the combining effects of seismic action with all static loads. The correctness, reliability and efficiency of the two parallel computational programs are verified with practical illustrations.

  13. Large-scale temporal analysis of computer and information science

    Soos, Sandor; Kampis, George; Gulyás, László

    2013-09-01

    The main aim of the project reported in this paper was twofold. One of the primary goals was to produce an extensive source of network data for bibliometric analyses of field dynamics in the case of Computer and Information Science. To this end, we rendered the raw material of the DBLP computer and infoscience bibliography into a comprehensive collection of dynamic network data, promptly available for further statistical analysis. The other goal was to demonstrate the value of our data source via its use in mapping Computer and Information Science (CIS). An analysis of the evolution of CIS was performed in terms of collaboration (co-authorship) network dynamics. Dynamic network analysis covered three quarters of the XX. century (76 years, from 1936 to date). Network evolution was described both at the macro- and the mezo level (in terms of community characteristics). Results show that the development of CIS followed what appears to be a universal pattern of growing into a "mature" discipline.

  14. [Physical image properties of digital radiography systems in low dose range].

    Kunitomo, Hiroshi; Ichikawa, Katsuhiro; Higashide, Ryo; Ohashi, Kazuya

    2012-01-01

    We measured physical image properties of a flat panel detector (FPD) system and a computed radiography (CR) system, targeting to a low dose range (reference dose: 2.58×10(-7) C/kg: to 1/20 dose). Input-output properties, pre-sampled modulation transfer functions (pre-sampled MTFs), and normalized noise power spectra for an FPD system equipped with a CsI scintillator (FPDcsi) and a CR system with an imaging plate coated with storage phosphor (CR) were measured at the low dose range for radiation quality of RQA3 (≍50 skV) and RQA5 (≍70 kV), and detective quantum efficiencies (DQEs) were calculated. In addition, in order to validate the DQE results, component fractions of Poisson and multiplicative and additive noise were analyzed using relative standard deviation analysis. The DQE values of FPDcsi were decreased with dose decrease, and contrarily to these, those of CR were increased. At the 1/10 and 1/20 doses for RQA3, the DQEs of FPDcsi and CR became almost the same. From the results of RSD analysis, it was proved that the main cause of DQE deterioration on FPDcsi are non-negligible additive (electronic) noise, and the DQE improvement on CR was caused by both of significant multiplicative (structure) noise and very low electronic noise. The DQE results were validated by comparing burger phantom images of each dose and radiation quality.

  15. COMPUTING

    I. Fisk

    2012-01-01

    Introduction Computing continued with a high level of activity over the winter in preparation for conferences and the start of the 2012 run. 2012 brings new challenges with a new energy, more complex events, and the need to make the best use of the available time before the Long Shutdown. We expect to be resource constrained on all tiers of the computing system in 2012 and are working to ensure the high-priority goals of CMS are not impacted. Heavy ions After a successful 2011 heavy-ion run, the programme is moving to analysis. During the run, the CAF resources were well used for prompt analysis. Since then in 2012 on average 200 job slots have been used continuously at Vanderbilt for analysis workflows. Operations Office As of 2012, the Computing Project emphasis has moved from commissioning to operation of the various systems. This is reflected in the new organisation structure where the Facilities and Data Operations tasks have been merged into a common Operations Office, which now covers everything ...

  16. COMPUTING

    P. McBride

    It has been a very active year for the computing project with strong contributions from members of the global community. The project has focused on site preparation and Monte Carlo production. The operations group has begun processing data from P5 as part of the global data commissioning. Improvements in transfer rates and site availability have been seen as computing sites across the globe prepare for large scale production and analysis as part of CSA07. Preparations for the upcoming Computing Software and Analysis Challenge CSA07 are progressing. Ian Fisk and Neil Geddes have been appointed as coordinators for the challenge. CSA07 will include production tests of the Tier-0 production system, reprocessing at the Tier-1 sites and Monte Carlo production at the Tier-2 sites. At the same time there will be a large analysis exercise at the Tier-2 centres. Pre-production simulation of the Monte Carlo events for the challenge is beginning. Scale tests of the Tier-0 will begin in mid-July and the challenge it...

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

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

    2016-01-01

    (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 pe

  18. Visualization and Data Analysis for High-Performance Computing

    Sewell, Christopher Meyer [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-27

    This is a set of slides from a guest lecture for a class at the University of Texas, El Paso on visualization and data analysis for high-performance computing. The topics covered are the following: trends in high-performance computing; scientific visualization, such as OpenGL, ray tracing and volume rendering, VTK, and ParaView; data science at scale, such as in-situ visualization, image databases, distributed memory parallelism, shared memory parallelism, VTK-m, "big data", and then an analysis example.

  19. Computational Analysis of the SRS Phase III Salt Disposition Alternatives

    Dimenna, R.A.

    1999-10-07

    Completion of the Phase III evaluation and comparison of salt disposition alternatives was supported with enhanced computer models and analysis for each case on the ''short list'' of four options. SPEEDUP(TM) models and special purpose models describing mass and energy balances and flow rates were developed and used to predict performance and production characteristics for each of the options. Results from the computational analysis were a key part of the input used to select a primary and an alternate salt disposition alternative.

  20. First Experiences with LHC Grid Computing and Distributed Analysis

    Fisk, Ian

    2010-12-01

    In this presentation the experiences of the LHC experiments using grid computing were presented with a focus on experience with distributed analysis. After many years of development, preparation, exercises, and validation the LHC (Large Hadron Collider) experiments are in operations. The computing infrastructure has been heavily utilized in the first 6 months of data collection. The general experience of exploiting the grid infrastructure for organized processing and preparation is described, as well as the successes employing the infrastructure for distributed analysis. At the end the expected evolution and future plans are outlined.

  1. Rigorous computer analysis of the Chow-Robbins game

    Häggström, Olle

    2012-01-01

    Flip a coin repeatedly, and stop whenever you want. Your payoff is the proportion of heads, and you wish to maximize this payoff in expectation. This so-called Chow-Robbins game is amenable to computer analysis, but while simple-minded number crunching can show that it is best to continue in a given position, establishing rigorously that stopping is optimal seems at first sight to require "backward induction from infinity". We establish a simple upper bound on the expected payoff in a given position, allowing efficient and rigorous computer analysis of positions early in the game. In particular we confirm that with 5 heads and 3 tails, stopping is optimal.

  2. Advances in computational design and analysis of airbreathing propulsion systems

    Klineberg, John M.

    1989-01-01

    The development of commercial and military aircraft depends, to a large extent, on engine manufacturers being able to achieve significant increases in propulsion capability through improved component aerodynamics, materials, and structures. The recent history of propulsion has been marked by efforts to develop computational techniques that can speed up the propulsion design process and produce superior designs. The availability of powerful supercomputers, such as the NASA Numerical Aerodynamic Simulator, and the potential for even higher performance offered by parallel computer architectures, have opened the door to the use of multi-dimensional simulations to study complex physical phenomena in propulsion systems that have previously defied analysis or experimental observation. An overview of several NASA Lewis research efforts is provided that are contributing toward the long-range goal of a numerical test-cell for the integrated, multidisciplinary design, analysis, and optimization of propulsion systems. Specific examples in Internal Computational Fluid Mechanics, Computational Structural Mechanics, Computational Materials Science, and High Performance Computing are cited and described in terms of current capabilities, technical challenges, and future research directions.

  3. Evaluation of Conventional Radiography and an Electronic Apex Locator in Determining the Working Length in C-shaped Canals

    Jafarzadeh, Hamid; Beyrami, Masoud; Forghani, Maryam

    2017-01-01

    Introduction: The purpose of this in vitro study was to compare the accuracy of working length determination using the apex locator versus conventional radiography in C-shaped canals. Methods and Materials: After confirming the actual C-shaped anatomy using cone-beam computed tomography (CBCT), 22 extracted C-shaped mandibular second molars were selected and decoronated at the cemento-enamel junction. The actual working length of these canals were determined by inserting a #15 K-file until the tip could be seen through the apical foramen and the working length was established by subtracting 0.5 mm from this length. The working length was also determined using conventional analog radiography and electronic apex locator (EAL) that were both compared with the actual working length. The data was statistically analyzed using paired t-test and marginal homogeneity test. Results: There was no significant differences between the working length obtained with apex locator and that achieved through conventional radiography in terms of measuring the mesiolingual and distal canals (P>0.05); while, significant differences were observed in measurements of the mesiobuccal canals (P=0.036). Within ±0.5 mm of tolerance margin there was no significant difference between EAL and conventional radiography. Conclusion: The apex locator was more accurate in determination of the working length of C-shaped canals compared with the conventional radiography. PMID:28179926

  4. Reconstructive dosimetry of radiological accidents - study of a brazilian case of industrial gamma radiography; Dosimetria reconstrutiva de acidentes radiologicos - estudo de um caso brasileiro de gamagrafia industrial

    Silva, Francisco Cesar Augusto da; Hunt, John G.; Ramalho, Adriana [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Pinto, Livia M.F. Amalfi [ARCtest - Servicos Tecnicos de Inspecao e Manutencao Industrial Ltda., Paulinia, SP (Brazil)]. E-mail: protecao@arctest.com.br

    2002-07-01

    On May 2000, an industrial gamma radiography operator, during a maintenance work of a {sup 60}Co irradiator, has suffered a radiological accident with severe consequences to the left hand. The experts of the High Doses Analysis Group (GADE/IRD/CNEN) initiated the reconstructive dosimetry for the radiation dose estimation, in order to determine the real dose received by the operator, and to help the medical evaluation for prescribing the medical procedures for treatment of the involved victim. This paper presents the reconstructive dosimetry performed through the determination of the radiation doses of the operator, based on theoretical, experimental and computational methods. For the computer methods, a program for the calculation of external doses were used, based on the Monte Carlo method, and a human body simulator composed by voxels. The values of effective and equivalent doses are also presented which has caused severe lesions on the operator hand.

  5. Study on the characterization of the neutron radiography facility in HANARO for two-phase flow research

    Lim, I. C.; Seo, C. G.; Jeong, J. H.; Lee, B. H.; Choi, Y. S

    2001-01-01

    For the application of dynamic neutron radiography to the two-phase flow research using HANARO, several experimental items to which the radiography technique is beneficial were identified through the review of the outputs from the related researches and the discussions with experts. Also, the investigation of the equipments including the beam port, camera and converter was made and a hardware and a software for image processing were equipped. It was confirmed that the calibration curve for the attenuation of neutron beam in fluid which is required for the two-phase flow experiment could be obtained by the computer code calculation. Based on the investigation results on the equipment and the results from the measurement of BNCT beam characteristics, a high speed camera and an image intensifier will be purchased. Then, the high speed dynamic neutron radiography facility for two-phase flow experiments will be fully equipped.

  6. Convergence Analysis of a Class of Computational Intelligence Approaches

    Junfeng Chen

    2013-01-01

    Full Text Available Computational intelligence approaches is a relatively new interdisciplinary field of research with many promising application areas. Although the computational intelligence approaches have gained huge popularity, it is difficult to analyze the convergence. In this paper, a computational model is built up for a class of computational intelligence approaches represented by the canonical forms of generic algorithms, ant colony optimization, and particle swarm optimization in order to describe the common features of these algorithms. And then, two quantification indices, that is, the variation rate and the progress rate, are defined, respectively, to indicate the variety and the optimality of the solution sets generated in the search process of the model. Moreover, we give four types of probabilistic convergence for the solution set updating sequences, and their relations are discussed. Finally, the sufficient conditions are derived for the almost sure weak convergence and the almost sure strong convergence of the model by introducing the martingale theory into the Markov chain analysis.

  7. Computational mathematics models, methods, and analysis with Matlab and MPI

    White, Robert E

    2004-01-01

    Computational Mathematics: Models, Methods, and Analysis with MATLAB and MPI explores and illustrates this process. Each section of the first six chapters is motivated by a specific application. The author applies a model, selects a numerical method, implements computer simulations, and assesses the ensuing results. These chapters include an abundance of MATLAB code. By studying the code instead of using it as a "black box, " you take the first step toward more sophisticated numerical modeling. The last four chapters focus on multiprocessing algorithms implemented using message passing interface (MPI). These chapters include Fortran 9x codes that illustrate the basic MPI subroutines and revisit the applications of the previous chapters from a parallel implementation perspective. All of the codes are available for download from www4.ncsu.edu./~white.This book is not just about math, not just about computing, and not just about applications, but about all three--in other words, computational science. Whether us...

  8. COMPUTING

    M. Kasemann P. McBride Edited by M-C. Sawley with contributions from: P. Kreuzer D. Bonacorsi S. Belforte F. Wuerthwein L. Bauerdick K. Lassila-Perini M-C. Sawley

    Introduction More than seventy CMS collaborators attended the Computing and Offline Workshop in San Diego, California, April 20-24th to discuss the state of readiness of software and computing for collisions. Focus and priority were given to preparations for data taking and providing room for ample dialog between groups involved in Commissioning, Data Operations, Analysis and MC Production. Throughout the workshop, aspects of software, operating procedures and issues addressing all parts of the computing model were discussed. Plans for the CMS participation in STEP’09, the combined scale testing for all four experiments due in June 2009, were refined. The article in CMS Times by Frank Wuerthwein gave a good recap of the highly collaborative atmosphere of the workshop. Many thanks to UCSD and to the organizers for taking care of this workshop, which resulted in a long list of action items and was definitely a success. A considerable amount of effort and care is invested in the estimate of the comput...

  9. Integration of rocket turbine design and analysis through computer graphics

    Hsu, Wayne; Boynton, Jim

    1988-01-01

    An interactive approach with engineering computer graphics is used to integrate the design and analysis processes of a rocket engine turbine into a progressive and iterative design procedure. The processes are interconnected through pre- and postprocessors. The graphics are used to generate the blade profiles, their stacking, finite element generation, and analysis presentation through color graphics. Steps of the design process discussed include pitch-line design, axisymmetric hub-to-tip meridional design, and quasi-three-dimensional analysis. The viscous two- and three-dimensional analysis codes are executed after acceptable designs are achieved and estimates of initial losses are confirmed.

  10. Sentiment analysis and ontology engineering an environment of computational intelligence

    Chen, Shyi-Ming

    2016-01-01

    This edited volume provides the reader with a fully updated, in-depth treatise on the emerging principles, conceptual underpinnings, algorithms and practice of Computational Intelligence in the realization of concepts and implementation of models of sentiment analysis and ontology –oriented engineering. The volume involves studies devoted to key issues of sentiment analysis, sentiment models, and ontology engineering. The book is structured into three main parts. The first part offers a comprehensive and prudently structured exposure to the fundamentals of sentiment analysis and natural language processing. The second part consists of studies devoted to the concepts, methodologies, and algorithmic developments elaborating on fuzzy linguistic aggregation to emotion analysis, carrying out interpretability of computational sentiment models, emotion classification, sentiment-oriented information retrieval, a methodology of adaptive dynamics in knowledge acquisition. The third part includes a plethora of applica...

  11. COMPUTING

    I. Fisk

    2011-01-01

    Introduction It has been a very active quarter in Computing with interesting progress in all areas. The activity level at the computing facilities, driven by both organised processing from data operations and user analysis, has been steadily increasing. The large-scale production of simulated events that has been progressing throughout the fall is wrapping-up and reprocessing with pile-up will continue. A large reprocessing of all the proton-proton data has just been released and another will follow shortly. The number of analysis jobs by users each day, that was already hitting the computing model expectations at the time of ICHEP, is now 33% higher. We are expecting a busy holiday break to ensure samples are ready in time for the winter conferences. Heavy Ion The Tier 0 infrastructure was able to repack and promptly reconstruct heavy-ion collision data. Two copies were made of the data at CERN using a large CASTOR disk pool, and the core physics sample was replicated ...

  12. Finite element dynamic analysis on CDC STAR-100 computer

    Noor, A. K.; Lambiotte, J. J., Jr.

    1978-01-01

    Computational algorithms are presented for the finite element dynamic analysis of structures on the CDC STAR-100 computer. The spatial behavior is described using higher-order finite elements. The temporal behavior is approximated by using either the central difference explicit scheme or Newmark's implicit scheme. In each case the analysis is broken up into a number of basic macro-operations. Discussion is focused on the organization of the computation and the mode of storage of different arrays to take advantage of the STAR pipeline capability. The potential of the proposed algorithms is discussed and CPU times are given for performing the different macro-operations for a shell modeled by higher order composite shallow shell elements having 80 degrees of freedom.

  13. Computer analysis of shells of revolution using asymptotic results

    Steele, C. R.; Ranjan, G. V.; Goto, C.; Pulliam, T. H.

    1979-01-01

    It is suggested that asymptotic results for the behavior of thin shells can be incorporated in a general computer code for the analysis of a complex shell structure. The advantage when compared to existing finite difference or finite element codes is a substantial reduction in computational labor with the capability of working to a specified level of accuracy. A reduction in user preparation time and dependance on user judgment is also gained, since mesh spacing can be internally generated. The general theory is described in this paper, as well as the implementation in the computer code FAST 1 (Functional Algorithm for Shell Theory) for the analysis of the general axisymmetric shell structure with axisymmetric loading.

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

    Khaial, Anas M.

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

  15. Numerical methods design, analysis, and computer implementation of algorithms

    Greenbaum, Anne

    2012-01-01

    Numerical Methods provides a clear and concise exploration of standard numerical analysis topics, as well as nontraditional ones, including mathematical modeling, Monte Carlo methods, Markov chains, and fractals. Filled with appealing examples that will motivate students, the textbook considers modern application areas, such as information retrieval and animation, and classical topics from physics and engineering. Exercises use MATLAB and promote understanding of computational results. The book gives instructors the flexibility to emphasize different aspects--design, analysis, or c

  16. Connecting Performance Analysis and Visualization to Advance Extreme Scale Computing

    Bremer, Peer-Timo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mohr, Bernd [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schulz, Martin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pasccci, Valerio [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gamblin, Todd [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brunst, Holger [Dresden Univ. of Technology (Germany)

    2015-07-29

    The characterization, modeling, analysis, and tuning of software performance has been a central topic in High Performance Computing (HPC) since its early beginnings. The overall goal is to make HPC software run faster on particular hardware, either through better scheduling, on-node resource utilization, or more efficient distributed communication.

  17. Computing support for advanced medical data analysis and imaging

    Wiślicki, W; Białas, P; Czerwiński, E; Kapłon, Ł; Kochanowski, A; Korcyl, G; Kowal, J; Kowalski, P; Kozik, T; Krzemień, W; Molenda, M; Moskal, P; Niedźwiecki, S; Pałka, M; Pawlik, M; Raczyński, L; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; Słomski, A; Smyrski, J; Strzelecki, A; Wieczorek, A; Zieliński, M; Zoń, N

    2014-01-01

    We discuss computing issues for data analysis and image reconstruction of PET-TOF medical scanner or other medical scanning devices producing large volumes of data. Service architecture based on the grid and cloud concepts for distributed processing is proposed and critically discussed.

  18. Digital radiography in the aerospace industry

    Buchanan, R. A.; Bueno, C.; Barry, R. C.; Barker, M. D.

    An account is given of the bases of digital radiography (DR), with a view to the identification of NDE systems with the greatest usefulness to the aerospace industry and the nature of the advanced image processing and reconstruction techniques that have been devised thus far. The spatial resolution of any DR system is fundamentally limited by the number of pixels in the digital image and the system field-of-view. Attention is given to the problems of image geometric unsharpness and radiation quantum noise limits, as well as to the potential role of advanced DR in future NDT of aerospace components.

  19. Digital Radiography Qualification of Tube Welding

    Carl, Chad

    2012-01-01

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

  20. Evaluation of cancer detection efficiency by means of hybrid and inverse filter in chest radiography

    Kim, Youn Young; Kim, Tae Young; Kim, Hyun Ji; Kim, Jung Min [Dept. of Radiological Science, Korea university, Seoul (Korea, Republic of); Park, Min Seock [Radiation Safety and Section, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2013-12-15

    The purpose of this study is to evaluate usefulness of Hybrid image and Inverse image about detection of tumor shadow in chest radiography using ROC analysis. Original images of 60 cases are selected from Standards digital image date base issued by the Japanese Society of Radiological Technology. Through computer language of C, Inverse images of 60 cases and Hybrid image of 30 cases are made. The continues reading experiment was conducted. In the case of inverse image were observed by 5 radiographer and 2 radiologist. In the case of In case of Hybrid image were observed by 3 student radiographer and 2 experienced radiographer. ROC curve are constructed using ROCKIT Program made by Metz. In Inverse image, a Az of average ROC curve was increases from 0.742 of original image to 0.775 of inverse image. In normal cases, the effect of the detrimental is same to that of the beneficial, however In abnormal cases, the beneficial effect is greater than detrimental effect. However in Hybrid image, a Az of average ROC curve was decreases from 0.5253 of original image to 0.4868 of Hybrid image. In Normal cases, the effect of the detrimental is greater than that of the Beneficial, however In abnormal cases, the Beneficial effect is greater than detrimental effect. The inverse image can be more positively considered for the detecting of tumor than the hybrid image.

  1. Benchmarking undedicated cloud computing providers for analysis of genomic datasets.

    Seyhan Yazar

    Full Text Available A major bottleneck in biological discovery is now emerging at the computational level. Cloud computing offers a dynamic means whereby small and medium-sized laboratories can rapidly adjust their computational capacity. We benchmarked two established cloud computing services, Amazon Web Services Elastic MapReduce (EMR on Amazon EC2 instances and Google Compute Engine (GCE, using publicly available genomic datasets (E.coli CC102 strain and a Han Chinese male genome and a standard bioinformatic pipeline on a Hadoop-based platform. Wall-clock time for complete assembly differed by 52.9% (95% CI: 27.5-78.2 for E.coli and 53.5% (95% CI: 34.4-72.6 for human genome, with GCE being more efficient than EMR. The cost of running this experiment on EMR and GCE differed significantly, with the costs on EMR being 257.3% (95% CI: 211.5-303.1 and 173.9% (95% CI: 134.6-213.1 more expensive for E.coli and human assemblies respectively. Thus, GCE was found to outperform EMR both in terms of cost and wall-clock time. Our findings confirm that cloud computing is an efficient and potentially cost-effective alternative for analysis of large genomic datasets. In addition to releasing our cost-effectiveness comparison, we present available ready-to-use scripts for establishing Hadoop instances with Ganglia monitoring on EC2 or GCE.

  2. Benchmarking undedicated cloud computing providers for analysis of genomic datasets.

    Yazar, Seyhan; Gooden, George E C; Mackey, David A; Hewitt, Alex W

    2014-01-01

    A major bottleneck in biological discovery is now emerging at the computational level. Cloud computing offers a dynamic means whereby small and medium-sized laboratories can rapidly adjust their computational capacity. We benchmarked two established cloud computing services, Amazon Web Services Elastic MapReduce (EMR) on Amazon EC2 instances and Google Compute Engine (GCE), using publicly available genomic datasets (E.coli CC102 strain and a Han Chinese male genome) and a standard bioinformatic pipeline on a Hadoop-based platform. Wall-clock time for complete assembly differed by 52.9% (95% CI: 27.5-78.2) for E.coli and 53.5% (95% CI: 34.4-72.6) for human genome, with GCE being more efficient than EMR. The cost of running this experiment on EMR and GCE differed significantly, with the costs on EMR being 257.3% (95% CI: 211.5-303.1) and 173.9% (95% CI: 134.6-213.1) more expensive for E.coli and human assemblies respectively. Thus, GCE was found to outperform EMR both in terms of cost and wall-clock time. Our findings confirm that cloud computing is an efficient and potentially cost-effective alternative for analysis of large genomic datasets. In addition to releasing our cost-effectiveness comparison, we present available ready-to-use scripts for establishing Hadoop instances with Ganglia monitoring on EC2 or GCE.

  3. Preliminary Study of Indirect Neutron Radiography Method at CARR

    WEI; Guo-hai; HAN; Song-bai; WANG; Hong-li; HE; Lin-feng; WANG; Yu; WU; Mei-mei; LIU; Yun-tao; CHEN; Dong-feng

    2013-01-01

    The Indirect Neutron Radiography is a powerful technique for non-destructively measuring specimens with radioactivity in the nuclear industrial field.China Advanced Research Reactor(CARR)is an excellent platform for Indirect Neutron Radiography and the experimental conditions based on CARR,mainly the first and the second exposure time,have been calculated and analyzed by the Monte Carlo

  4. Cartographic Modeling: Computer-assisted Analysis of Spatially Defined Neighborhoods

    Berry, J. K.; Tomlin, C. D.

    1982-01-01

    Cartographic models addressing a wide variety of applications are composed of fundamental map processing operations. These primitive operations are neither data base nor application-specific. By organizing the set of operations into a mathematical-like structure, the basis for a generalized cartographic modeling framework can be developed. Among the major classes of primitive operations are those associated with reclassifying map categories, overlaying maps, determining distance and connectivity, and characterizing cartographic neighborhoods. The conceptual framework of cartographic modeling is established and techniques for characterizing neighborhoods are used as a means of demonstrating some of the more sophisticated procedures of computer-assisted map analysis. A cartographic model for assessing effective roundwood supply is briefly described as an example of a computer analysis. Most of the techniques described have been implemented as part of the map analysis package developed at the Yale School of Forestry and Environmental Studies.

  5. Computer Vision-Based Image Analysis of Bacteria.

    Danielsen, Jonas; Nordenfelt, Pontus

    2017-01-01

    Microscopy is an essential tool for studying bacteria, but is today mostly used in a qualitative or possibly semi-quantitative manner often involving time-consuming manual analysis. It also makes it difficult to assess the importance of individual bacterial phenotypes, especially when there are only subtle differences in features such as shape, size, or signal intensity, which is typically very difficult for the human eye to discern. With computer vision-based image analysis - where computer algorithms interpret image data - it is possible to achieve an objective and reproducible quantification of images in an automated fashion. Besides being a much more efficient and consistent way to analyze images, this can also reveal important information that was previously hard to extract with traditional methods. Here, we present basic concepts of automated image processing, segmentation and analysis that can be relatively easy implemented for use with bacterial research.

  6. Computer Analysis Of ILO Standard Chest Radiographs Of Pneumoconiosis

    Li, C. C.; Shu, David B. C.; Tai, H. T.; Hou, W.; Kunkle, G. A.; Wang, Y.; Hoy, R. J.

    1982-11-01

    This paper presents study of computer analysis of the 1980 ILO standard chest radiographs of pneumoconiosis. Algorithms developed for detection of individual small rounded and irregular opacities have been experimented and evaluated on these standard radiographs. The density, shape, and size distribution of the detected objects in the lung field, in spite of false positives, can be used as indicators for the beginning of pneumoconiosis. This approach is potentially useful in computer-assisted screening and early detection process where the annual chest radiograph of each worker is compared with his (her) own normal radiograph obtained previously.

  7. EST analysis pipeline: use of distributed computing resources.

    González, Francisco Javier; Vizcaíno, Juan Antonio

    2011-01-01

    This chapter describes how a pipeline for the analysis of expressed sequence tag (EST) data can be -implemented, based on our previous experience generating ESTs from Trichoderma spp. We focus on key steps in the workflow, such as the processing of raw data from the sequencers, the clustering of ESTs, and the functional annotation of the sequences using BLAST, InterProScan, and BLAST2GO. Some of the steps require the use of intensive computing power. Since these resources are not available for small research groups or institutes without bioinformatics support, an alternative will be described: the use of distributed computing resources (local grids and Amazon EC2).

  8. Computation system for nuclear reactor core analysis. [LMFBR

    Vondy, D.R.; Fowler, T.B.; Cunningham, G.W.; Petrie, L.M.

    1977-04-01

    This report documents a system which contains computer codes as modules developed to evaluate nuclear reactor core performance. The diffusion theory approximation to neutron transport may be applied with the VENTURE code treating up to three dimensions. The effect of exposure may be determined with the BURNER code, allowing depletion calculations to be made. The features and requirements of the system are discussed and aspects common to the computational modules, but the latter are documented elsewhere. User input data requirements, data file management, control, and the modules which perform general functions are described. Continuing development and implementation effort is enhancing the analysis capability available locally and to other installations from remote terminals.

  9. CAR: A MATLAB Package to Compute Correspondence Analysis with Rotations

    Urbano Lorenzo-Seva Rovira

    2009-09-01

    Full Text Available Correspondence analysis (CA is a popular method that can be used to analyse relationships between categorical variables. Like principal component analysis, CA solutions can be rotated both orthogonally and obliquely to simple structure without affecting the total amount of explained inertia. We describe a MATLAB package for computing CA. The package includes orthogonal and oblique rotation of axes. It is designed not only for advanced users of MATLAB but also for beginners. Analysis can be done using a user-friendly interface, or by using command lines. We illustrate the use of CAR with one example.

  10. COMPUTING

    M. Kasemann

    Introduction More than seventy CMS collaborators attended the Computing and Offline Workshop in San Diego, California, April 20-24th to discuss the state of readiness of software and computing for collisions. Focus and priority were given to preparations for data taking and providing room for ample dialog between groups involved in Commissioning, Data Operations, Analysis and MC Production. Throughout the workshop, aspects of software, operating procedures and issues addressing all parts of the computing model were discussed. Plans for the CMS participation in STEP’09, the combined scale testing for all four experiments due in June 2009, were refined. The article in CMS Times by Frank Wuerthwein gave a good recap of the highly collaborative atmosphere of the workshop. Many thanks to UCSD and to the organizers for taking care of this workshop, which resulted in a long list of action items and was definitely a success. A considerable amount of effort and care is invested in the estimate of the co...

  11. COMPUTING

    M. Kasemann

    Introduction During the past six months, Computing participated in the STEP09 exercise, had a major involvement in the October exercise and has been working with CMS sites on improving open issues relevant for data taking. At the same time operations for MC production, real data reconstruction and re-reconstructions and data transfers at large scales were performed. STEP09 was successfully conducted in June as a joint exercise with ATLAS and the other experiments. It gave good indication about the readiness of the WLCG infrastructure with the two major LHC experiments stressing the reading, writing and processing of physics data. The October Exercise, in contrast, was conducted as an all-CMS exercise, where Physics, Computing and Offline worked on a common plan to exercise all steps to efficiently access and analyze data. As one of the major results, the CMS Tier-2s demonstrated to be fully capable for performing data analysis. In recent weeks, efforts were devoted to CMS Computing readiness. All th...

  12. COMPUTING

    M. Kasemann

    CCRC’08 challenges and CSA08 During the February campaign of the Common Computing readiness challenges (CCRC’08), the CMS computing team had achieved very good results. The link between the detector site and the Tier0 was tested by gradually increasing the number of parallel transfer streams well beyond the target. Tests covered the global robustness at the Tier0, processing a massive number of very large files and with a high writing speed to tapes.  Other tests covered the links between the different Tiers of the distributed infrastructure and the pre-staging and reprocessing capacity of the Tier1’s: response time, data transfer rate and success rate for Tape to Buffer staging of files kept exclusively on Tape were measured. In all cases, coordination with the sites was efficient and no serious problem was found. These successful preparations prepared the ground for the second phase of the CCRC’08 campaign, in May. The Computing Software and Analysis challen...

  13. Assessment of the canal fillings using cone beam computed tomography and digital periapical radiography%锥形束CT与数字化根尖片对根充效果的评价

    何辰菲; 邹德荣

    2015-01-01

    目的:比较锥形束CT(CBCT)与根尖片对根管充填后效果的评价,进一步探讨CBCT在根管治疗中的优势及应用价值。方法选取经临床诊断需要进行根管治疗的100颗患牙(221例根管),根管充填后同步拍摄根尖片与CBCT,术后分别由2位经验丰富的临床医生从根管充填的有效长度与严密程度两方面进行读片,运用卡方检验比较2种方法是否在评价结果上存在差异性。结果总计充填根管214例,充填遗漏7例,在根管充填长度、严密程度及满意程度评价方面,分别约有34.58%、30.48%和37.58%的根管在数字化根尖片与CBCT的评价结果上未能达成一致意见,经过统计学检验,数字化根尖片与CBCT在上述三方面的评价均有高度显著性差异(P <0.01)。结论 CBCT较根尖片在根管治疗术的长度及严密程度评价方面更为灵敏及准确,在复杂或疑难的根管治疗术中拥有很高的临床应用价值。%Objective To compare the root filling quality assessed by cone-beam computed tomography (CBCT)and periapical radio-graphs (PA),and to explore the advantage and application value of CBCT in the root canal treatment. Methods In total,100 teeth (221 canals)were clinically diagnosed and received root canal therapy. After root canal filling,the length and density of root filling were as-sessed with PA and CBCT simultaneously by two experienced endodontists. Chi-square test was performed with the data from PA or CBCT to evaluate the quality of the root filling. Results In total,214 canals received root-canal treatment while 7 canals were omitted. In terms of length,density and satisfaction of the root filling,there were about 34. 58%,30. 48% and 37. 58% of canals demonstrated different re-sults based on the evaluation from PA and CBCT respectively. According to the result of statistical test,PA and CBCT had significant differences (P <0. 01)in the assessment of the three

  14. Clinical Applications of Reverse Panoramic Radiography

    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.

  15. CFD Analysis and Design Optimization Using Parallel Computers

    Martinelli, Luigi; Alonso, Juan Jose; Jameson, Antony; Reuther, James

    1997-01-01

    A versatile and efficient multi-block method is presented for the simulation of both steady and unsteady flow, as well as aerodynamic design optimization of complete aircraft configurations. The compressible Euler and Reynolds Averaged Navier-Stokes (RANS) equations are discretized using a high resolution scheme on body-fitted structured meshes. An efficient multigrid implicit scheme is implemented for time-accurate flow calculations. Optimum aerodynamic shape design is achieved at very low cost using an adjoint formulation. The method is implemented on parallel computing systems using the MPI message passing interface standard to ensure portability. The results demonstrate that, by combining highly efficient algorithms with parallel computing, it is possible to perform detailed steady and unsteady analysis as well as automatic design for complex configurations using the present generation of parallel computers.

  16. Automatic behaviour analysis system for honeybees using computer vision

    Tu, Gang Jun; Hansen, Mikkel Kragh; Kryger, Per

    2016-01-01

    -cost embedded computer with very limited computational resources as compared to an ordinary PC. The system succeeds in counting honeybees, identifying their position and measuring their in-and-out activity. Our algorithm uses background subtraction method to segment the images. After the segmentation stage......, the methods are primarily based on statistical analysis and inference. The regression statistics (i.e. R2) of the comparisons of system predictions and manual counts are 0.987 for counting honeybees, and 0.953 and 0.888 for measuring in-activity and out-activity, respectively. The experimental results...... demonstrate that this system can be used as a tool to detect the behaviour of honeybees and assess their state in the beehive entrance. Besides, the result of the computation time show that the Raspberry Pi is a viable solution in such real-time video processing system....

  17. High Brightness Neutron Source for Radiography

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

    2008-12-08

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

  18. wolfPAC: building a high-performance distributed computing network for phylogenetic analysis using 'obsolete' computational resources.

    Reeves, Patrick A; Friedman, Philip H; Richards, Christopher M

    2005-01-01

    wolfPAC is an AppleScript-based software package that facilitates the use of numerous, remotely located Macintosh computers to perform computationally-intensive phylogenetic analyses using the popular application PAUP* (Phylogenetic Analysis Using Parsimony). It has been designed to utilise readily available, inexpensive processors and to encourage sharing of computational resources within the worldwide phylogenetics community.

  19. COMPUTING

    2010-01-01

    Introduction Just two months after the “LHC First Physics” event of 30th March, the analysis of the O(200) million 7 TeV collision events in CMS accumulated during the first 60 days is well under way. The consistency of the CMS computing model has been confirmed during these first weeks of data taking. This model is based on a hierarchy of use-cases deployed between the different tiers and, in particular, the distribution of RECO data to T1s, who then serve data on request to T2s, along a topology known as “fat tree”. Indeed, during this period this model was further extended by almost full “mesh” commissioning, meaning that RECO data were shipped to T2s whenever possible, enabling additional physics analyses compared with the “fat tree” model. Computing activities at the CMS Analysis Facility (CAF) have been marked by a good time response for a load almost evenly shared between ALCA (Alignment and Calibration tasks - highest p...

  20. Emerging Trends and Statistical Analysis in Computational Modeling in Agriculture

    Sunil Kumar

    2015-03-01

    Full Text Available In this paper the authors have tried to describe emerging trend in computational modelling used in the sphere of agriculture. Agricultural computational modelling with the use of intelligence techniques for computing the agricultural output by providing minimum input data to lessen the time through cutting down the multi locational field trials and also the labours and other inputs is getting momentum. Development of locally suitable integrated farming systems (IFS is the utmost need of the day, particularly in India where about 95% farms are under small and marginal holding size. Optimization of the size and number of the various enterprises to the desired IFS model for a particular set of agro-climate is essential components of the research to sustain the agricultural productivity for not only filling the stomach of the bourgeoning population of the country, but also to enhance the nutritional security and farms return for quality life. Review of literature pertaining to emerging trends in computational modelling applied in field of agriculture is done and described below for the purpose of understanding its trends mechanism behavior and its applications. Computational modelling is increasingly effective for designing and analysis of the system. Computa-tional modelling is an important tool to analyses the effect of different scenarios of climate and management options on the farming systems and its interaction among themselves. Further, authors have also highlighted the applications of computational modeling in integrated farming system, crops, weather, soil, climate, horticulture and statistical used in agriculture which can show the path to the agriculture researcher and rural farming community to replace some of the traditional techniques.

  1. Visual Analysis of Cloud Computing Performance Using Behavioral Lines.

    Muelder, Chris; Zhu, Biao; Chen, Wei; Zhang, Hongxin; Ma, Kwan-Liu

    2016-02-29

    Cloud computing is an essential technology to Big Data analytics and services. A cloud computing system is often comprised of a large number of parallel computing and storage devices. Monitoring the usage and performance of such a system is important for efficient operations, maintenance, and security. Tracing every application on a large cloud system is untenable due to scale and privacy issues. But profile data can be collected relatively efficiently by regularly sampling the state of the system, including properties such as CPU load, memory usage, network usage, and others, creating a set of multivariate time series for each system. Adequate tools for studying such large-scale, multidimensional data are lacking. In this paper, we present a visual based analysis approach to understanding and analyzing the performance and behavior of cloud computing systems. Our design is based on similarity measures and a layout method to portray the behavior of each compute node over time. When visualizing a large number of behavioral lines together, distinct patterns often appear suggesting particular types of performance bottleneck. The resulting system provides multiple linked views, which allow the user to interactively explore the data by examining the data or a selected subset at different levels of detail. Our case studies, which use datasets collected from two different cloud systems, show that this visual based approach is effective in identifying trends and anomalies of the systems.

  2. Assessing computer waste generation in Chile using material flow analysis.

    Steubing, Bernhard; Böni, Heinz; Schluep, Mathias; Silva, Uca; Ludwig, Christian

    2010-03-01

    The quantities of e-waste are expected to increase sharply in Chile. The purpose of this paper is to provide a quantitative data basis on generated e-waste quantities. A material flow analysis was carried out assessing the generation of e-waste from computer equipment (desktop and laptop PCs as well as CRT and LCD-monitors). Import and sales data were collected from the Chilean Customs database as well as from publications by the International Data Corporation. A survey was conducted to determine consumers' choices with respect to storage, re-use and disposal of computer equipment. The generation of e-waste was assessed in a baseline as well as upper and lower scenarios until 2020. The results for the baseline scenario show that about 10,000 and 20,000 tons of computer waste may be generated in the years 2010 and 2020, respectively. The cumulative e-waste generation will be four to five times higher in the upcoming decade (2010-2019) than during the current decade (2000-2009). By 2020, the shares of LCD-monitors and laptops will increase more rapidly replacing other e-waste including the CRT-monitors. The model also shows the principal flows of computer equipment from production and sale to recycling and disposal. The re-use of computer equipment plays an important role in Chile. An appropriate recycling scheme will have to be introduced to provide adequate solutions for the growing rate of e-waste generation.

  3. A Research Roadmap for Computation-Based Human Reliability Analysis

    Boring, Ronald [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Joe, Jeffrey [Idaho National Lab. (INL), Idaho Falls, ID (United States); Smith, Curtis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Groth, Katrina [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-08-01

    The United States (U.S.) Department of Energy (DOE) is sponsoring research through the Light Water Reactor Sustainability (LWRS) program to extend the life of the currently operating fleet of commercial nuclear power plants. The Risk Informed Safety Margin Characterization (RISMC) research pathway within LWRS looks at ways to maintain and improve the safety margins of these plants. The RISMC pathway includes significant developments in the area of thermalhydraulics code modeling and the development of tools to facilitate dynamic probabilistic risk assessment (PRA). PRA is primarily concerned with the risk of hardware systems at the plant; yet, hardware reliability is often secondary in overall risk significance to human errors that can trigger or compound undesirable events at the plant. This report highlights ongoing efforts to develop a computation-based approach to human reliability analysis (HRA). This computation-based approach differs from existing static and dynamic HRA approaches in that it: (i) interfaces with a dynamic computation engine that includes a full scope plant model, and (ii) interfaces with a PRA software toolset. The computation-based HRA approach presented in this report is called the Human Unimodels for Nuclear Technology to Enhance Reliability (HUNTER) and incorporates in a hybrid fashion elements of existing HRA methods to interface with new computational tools developed under the RISMC pathway. The goal of this research effort is to model human performance more accurately than existing approaches, thereby minimizing modeling uncertainty found in current plant risk models.

  4. Advanced computational tools for 3-D seismic analysis

    Barhen, J.; Glover, C.W.; Protopopescu, V.A. [Oak Ridge National Lab., TN (United States)] [and others

    1996-06-01

    The global objective of this effort is to develop advanced computational tools for 3-D seismic analysis, and test the products using a model dataset developed under the joint aegis of the United States` Society of Exploration Geophysicists (SEG) and the European Association of Exploration Geophysicists (EAEG). The goal is to enhance the value to the oil industry of the SEG/EAEG modeling project, carried out with US Department of Energy (DOE) funding in FY` 93-95. The primary objective of the ORNL Center for Engineering Systems Advanced Research (CESAR) is to spearhead the computational innovations techniques that would enable a revolutionary advance in 3-D seismic analysis. The CESAR effort is carried out in collaboration with world-class domain experts from leading universities, and in close coordination with other national laboratories and oil industry partners.

  5. Computational singular perturbation analysis of stochastic chemical systems with stiffness

    Wang, Lijin; Han, Xiaoying; Cao, Yanzhao; Najm, Habib N.

    2017-04-01

    Computational singular perturbation (CSP) is a useful method for analysis, reduction, and time integration of stiff ordinary differential equation systems. It has found dominant utility, in particular, in chemical reaction systems with a large range of time scales at continuum and deterministic level. On the other hand, CSP is not directly applicable to chemical reaction systems at micro or meso-scale, where stochasticity plays an non-negligible role and thus has to be taken into account. In this work we develop a novel stochastic computational singular perturbation (SCSP) analysis and time integration framework, and associated algorithm, that can be used to not only construct accurately and efficiently the numerical solutions to stiff stochastic chemical reaction systems, but also analyze the dynamics of the reduced stochastic reaction systems. The algorithm is illustrated by an application to a benchmark stochastic differential equation model, and numerical experiments are carried out to demonstrate the effectiveness of the construction.

  6. Towards Advanced Data Analysis by Combining Soft Computing and Statistics

    Gil, María; Sousa, João; Verleysen, Michel

    2013-01-01

    Soft computing, as an engineering science, and statistics, as a classical branch of mathematics, emphasize different aspects of data analysis. Soft computing focuses on obtaining working solutions quickly, accepting approximations and unconventional approaches. Its strength lies in its flexibility to create models that suit the needs arising in applications. In addition, it emphasizes the need for intuitive and interpretable models, which are tolerant to imprecision and uncertainty. Statistics is more rigorous and focuses on establishing objective conclusions based on experimental data by analyzing the possible situations and their (relative) likelihood. It emphasizes the need for mathematical methods and tools to assess solutions and guarantee performance. Combining the two fields enhances the robustness and generalizability of data analysis methods, while preserving the flexibility to solve real-world problems efficiently and intuitively.

  7. Computers in activation analysis and gamma-ray spectroscopy

    Carpenter, B. S.; D' Agostino, M. D.; Yule, H. P. [eds.

    1979-01-01

    Seventy-three papers are included under the following session headings: analytical and mathematical methods for data analysis; software systems for ..gamma..-ray and x-ray spectrometry; ..gamma..-ray spectra treatment, peak evaluation; least squares; IAEA intercomparison of methods for processing spectra; computer and calculator utilization in spectrometer systems; and applications in safeguards, fuel scanning, and environmental monitoring. Separate abstracts were prepared for 72 of those papers. (DLC)

  8. Analysis of diabetic retinopathy biomarker VEGF gene by computational approaches

    Jayashree Sadasivam; Ramesh, N.; K. Vijayalakshmi; Vinni Viridi; Shiva prasad

    2012-01-01

    Diabetic retinopathy, the most common diabetic eye disease, is caused by changes in the blood vessels of the retina which remains the major cause. It is characterized by vascular permeability and increased tissue ischemia and angiogenesis. One of the biomarker for Diabetic retinopathy has been identified as Vascular Endothelial Growth Factor ( VEGF )gene by computational analysis. VEGF is a sub-family of growth factors, the platelet-derived growth factor family of cystine-knot growth factors...

  9. Vector Field Visual Data Analysis Technologies for Petascale Computational Science

    Garth, Christoph; Deines, Eduard; Joy, Kenneth I.; Bethel, E. Wes; Childs, Hank; Weber, Gunther; Ahern, Sean; Pugmire, Dave; Sanderson, Allen; Johnson, Chris

    2009-11-13

    State-of-the-art computational science simulations generate large-scale vector field data sets. Visualization and analysis is a key aspect of obtaining insight into these data sets and represents an important challenge. This article discusses possibilities and challenges of modern vector field visualization and focuses on methods and techniques developed in the SciDAC Visualization and Analytics Center for Enabling Technologies (VACET) and deployed in the open-source visualization tool, VisIt.

  10. Trend Analysis of the Brazilian Scientific Production in Computer Science

    TRUCOLO, C. C.

    2014-12-01

    Full Text Available The growth of scientific information volume and diversity brings new challenges in order to understand the reasons, the process and the real essence that propel this growth. This information can be used as the basis for the development of strategies and public politics to improve the education and innovation services. Trend analysis is one of the steps in this way. In this work, trend analysis of Brazilian scientific production of graduate programs in the computer science area is made to identify the main subjects being studied by these programs in general and individual ways.

  11. Structural mode significance using INCA. [Interactive Controls Analysis computer program

    Bauer, Frank H.; Downing, John P.; Thorpe, Christopher J.

    1990-01-01

    Structural finite element models are often too large to be used in the design and analysis of control systems. Model reduction techniques must be applied to reduce the structural model to manageable size. In the past, engineers either performed the model order reduction by hand or used distinct computer programs to retrieve the data, to perform the significance analysis and to reduce the order of the model. To expedite this process, the latest version of INCA has been expanded to include an interactive graphical structural mode significance and model order reduction capability.

  12. Analysis and computation of microstructure in finite plasticity

    Hackl, Klaus

    2015-01-01

    This book addresses the need for a fundamental understanding of the physical origin, the mathematical behavior, and the numerical treatment of models which include microstructure. Leading scientists present their efforts involving mathematical analysis, numerical analysis, computational mechanics, material modelling and experiment. The mathematical analyses are based on methods from the calculus of variations, while in the numerical implementation global optimization algorithms play a central role. The modeling covers all length scales, from the atomic structure up to macroscopic samples. The development of the models ware guided by experiments on single and polycrystals, and results will be checked against experimental data.

  13. Computer Use, Confidence, Attitudes, and Knowledge: A Causal Analysis.

    Levine, Tamar; Donitsa-Schmidt, Smadar

    1998-01-01

    Introduces a causal model which links measures of computer experience, computer-related attitudes, computer-related confidence, and perceived computer-based knowledge. The causal model suggests that computer use has a positive effect on perceived computer self-confidence, as well as on computer-related attitudes. Questionnaires were administered…

  14. Computer vision analysis of image motion by variational methods

    Mitiche, Amar

    2014-01-01

    This book presents a unified view of image motion analysis under the variational framework. Variational methods, rooted in physics and mechanics, but appearing in many other domains, such as statistics, control, and computer vision, address a problem from an optimization standpoint, i.e., they formulate it as the optimization of an objective function or functional. The methods of image motion analysis described in this book use the calculus of variations to minimize (or maximize) an objective functional which transcribes all of the constraints that characterize the desired motion variables. The book addresses the four core subjects of motion analysis: Motion estimation, detection, tracking, and three-dimensional interpretation. Each topic is covered in a dedicated chapter. The presentation is prefaced by an introductory chapter which discusses the purpose of motion analysis. Further, a chapter is included which gives the basic tools and formulae related to curvature, Euler Lagrange equations, unconstrained de...

  15. Non-destructive Testing Dummy Nuclear Fuel Rods by Neutron Radiography

    WEI; Guo-hai; HAN; Song-bai; HE; Lin-feng; WANG; Yu; WANG; Hong-li; LIU; Yun-tao; CHEN; Dong-feng

    2013-01-01

    As a unique non-destructive testing technique,neutron radiography can be used to measure nuclear fuel rods with radioactivity.The images of the dummy nuclear fuel rods were obtained at the CARR.Through imaging analysis methods,the structure defections,the hydrogen accumulation in the cladding and the 235U enrichment of the pellet were studied and analyzed.Experiences for non-destructive testing real PWR nuclear fuel rods by NR

  16. COMPUTING

    I. Fisk

    2012-01-01

      Introduction Computing activity has been running at a sustained, high rate as we collect data at high luminosity, process simulation, and begin to process the parked data. The system is functional, though a number of improvements are planned during LS1. Many of the changes will impact users, we hope only in positive ways. We are trying to improve the distributed analysis tools as well as the ability to access more data samples more transparently.  Operations Office Figure 2: Number of events per month, for 2012 Since the June CMS Week, Computing Operations teams successfully completed data re-reconstruction passes and finished the CMSSW_53X MC campaign with over three billion events available in AOD format. Recorded data was successfully processed in parallel, exceeding 1.2 billion raw physics events per month for the first time in October 2012 due to the increase in data-parking rate. In parallel, large efforts were dedicated to WMAgent development and integrati...

  17. COMPUTING

    P. MacBride

    The Computing Software and Analysis Challenge CSA07 has been the main focus of the Computing Project for the past few months. Activities began over the summer with the preparation of the Monte Carlo data sets for the challenge and tests of the new production system at the Tier-0 at CERN. The pre-challenge Monte Carlo production was done in several steps: physics generation, detector simulation, digitization, conversion to RAW format and the samples were run through the High Level Trigger (HLT). The data was then merged into three "Soups": Chowder (ALPGEN), Stew (Filtered Pythia) and Gumbo (Pythia). The challenge officially started when the first Chowder events were reconstructed on the Tier-0 on October 3rd. The data operations teams were very busy during the the challenge period. The MC production teams continued with signal production and processing while the Tier-0 and Tier-1 teams worked on splitting the Soups into Primary Data Sets (PDS), reconstruction and skimming. The storage sys...

  18. Use of VAP3D software for production and manipulation of synthetic radiographies of anthropomorphic models

    Lima, Lindeval Fernandes de, E-mail: lindeval@dmat.ufrr.b [Universidade Federal de Roraima (DMAT/UFRR), Boa Vista, RR (Brazil). Dept. de Matematica; Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Vieira, Jose W. [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil); Universidade de Pernambuco (EPP/UPE), Recife, PE (Brazil). Escola Politecnica de Pernambuco; Lima, Fernando R.A., E-mail: falima@cnen.gov.b [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Leal Neto, Viriato [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2011-07-01

    The Grupo de Dosimetria Numerica has developed exposure computational models (ECM) involving a Monte Carlo code and voxel phantoms to simulate various situations of internal and external exposure to ionizing radiation. Most analyses of the produced results are presented in tables and graphics formats. An alternative to this traditional way of analyzing results is to save voxels of Regions of Interest (ROI) of the phantom irradiated with information like the location of the voxel and the energy deposited in it during the simulation. Such information can be saved to a text file and later turned into 3D objects. In this paper the VAP3D software has been used to read text files produced in simulations using the ECM of DEN (Nuclear Energy Dept. - UFPE), converting them into binary files of the type RAW, and visualize them. In order to reflect the radiosensitivity of the organs and tissues suggested by ICRP-60, for conversion of text file to binary, of the energy deposited values are multiplied by the weighting factor of the tissue to which the voxel belongs. The result of the multiplication is normalized to the interval [0, 255]. The files transformed are referred herein as synthetic radiographies. In VAP3D software, it is possible to generate stacks from theses radiographies in transverse, sagittal and coronal directions. In order to illustrate the production of synthetic radiographies, some images are presented in this paper, and dosimetric results are obtained from a variety of ROIs of the phantoms of DEN for radiological exams. (author)

  19. Miniature, mobile X-ray computed radiography system

    Watson, Scott A; Rose, Evan A

    2017-03-07

    A miniature, portable x-ray system may be configured to scan images stored on a phosphor. A flash circuit may be configured to project red light onto a phosphor and receive blue light from the phosphor. A digital monochrome camera may be configured to receive the blue light to capture an article near the phosphor.

  20. Development of the USAF Computed Radiography (CR) Process Control

    2008-11-01

    information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YY) 2...AFB), Senior Master Sergeant Tania Hollinshed and Master Sergeant John Kelley (Whiteman AFB); and Ms. Marianne Ramsey (Materials Integrity Branch) for...T.O. 33B-1-2 guidance needs to be developed to address monitor process control; IP cleaning , handling, and storage; and general equivalency guidelines

  1. COMPUTING

    I. Fisk

    2011-01-01

    Introduction The Computing Team successfully completed the storage, initial processing, and distribution for analysis of proton-proton data in 2011. There are still a variety of activities ongoing to support winter conference activities and preparations for 2012. Heavy ions The heavy-ion run for 2011 started in early November and has already demonstrated good machine performance and success of some of the more advanced workflows planned for 2011. Data collection will continue until early December. Facilities and Infrastructure Operations Operational and deployment support for WMAgent and WorkQueue+Request Manager components, routinely used in production by Data Operations, are provided. The GlideInWMS and components installation are now deployed at CERN, which is added to the GlideInWMS factory placed in the US. There has been new operational collaboration between the CERN team and the UCSD GlideIn factory operators, covering each others time zones by monitoring/debugging pilot jobs sent from the facto...

  2. A Lumped Computational Model for Sodium Sulfur Battery Analysis

    Wu, Fan

    Due to the cost of materials and time consuming testing procedures, development of new batteries is a slow and expensive practice. The purpose of this study is to develop a computational model and assess the capabilities of such a model designed to aid in the design process and control of sodium sulfur batteries. To this end, a transient lumped computational model derived from an integral analysis of the transport of species, energy and charge throughout the battery has been developed. The computation processes are coupled with the use of Faraday's law, and solutions for the species concentrations, electrical potential and current are produced in a time marching fashion. Properties required for solving the governing equations are calculated and updated as a function of time based on the composition of each control volume. The proposed model is validated against multi- dimensional simulations and experimental results from literatures, and simulation results using the proposed model is presented and analyzed. The computational model and electrochemical model used to solve the equations for the lumped model are compared with similar ones found in the literature. The results obtained from the current model compare favorably with those from experiments and other models.

  3. Measuring microfocus focal spots using digital radiography

    Fry, David A [Los Alamos National Laboratory

    2009-01-01

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

  4. Polarized neutron radiography with a periscope

    Schulz, Michael; Neubauer, Andreas; Mühlbauer, Martin; Calzada, Elbio; Schillinger, Burkhard; Pfleiderer, Christian; Böni, Peter

    2010-01-01

    The interaction of the magnetic moment of the neutron with magnetic fields provides a powerful probe for spatially resolved magnetisation measurements in magnetic materials. We have tested a periscope as a new type of polarizer providing neutron beams with a high polarization and a low divergence. The observed inhomogeneity of the beam caused by the waviness of the glass substrates was quantified by means of Monte-Carlo simulations using the software package McStas. The results show that beams of high homogeneity can be produced if the waviness is reduced to below 1.0·10-5 rad. Finally, it is shown that radiography with polarized neutrons is a powerful method for measuring the spatially resolved magnetisation in optically float-zoned samples of the weak itinerant ferromagnet Ni3Al, thereby aiding the identification of the appropriate growth parameters.

  5. Polarized neutron radiography with a periscope

    Schulz, Michael; Neubauer, Andreas; Muehlbauer, Martin; Schillinger, Burkhard; Pfleiderer, Christian; Boeni, Peter [Technische Universitaet Muenchen, Physik Department, E21, Garching (Germany); Calzada, Elbio, E-mail: michael.schulz@frm2.tum.d [Technische Universitaet Muenchen, Forschungsneutronenquelle Heinz Maier Leibnitz (FRM II), Garching (Germany)

    2010-01-01

    The interaction of the magnetic moment of the neutron with magnetic fields provides a powerful probe for spatially resolved magnetisation measurements in magnetic materials. We have tested a periscope as a new type of polarizer providing neutron beams with a high polarization and a low divergence. The observed inhomogeneity of the beam caused by the waviness of the glass substrates was quantified by means of Monte-Carlo simulations using the software package McStas. The results show that beams of high homogeneity can be produced if the waviness is reduced to below 1.0{center_dot}10{sup -5} rad. Finally, it is shown that radiography with polarized neutrons is a powerful method for measuring the spatially resolved magnetisation in optically float-zoned samples of the weak itinerant ferromagnet Ni{sub 3}Al, thereby aiding the identification of the appropriate growth parameters.

  6. Digital radiography exposure indices: A review

    Mothiram, Ursula; Brennan, Patrick C; Lewis, Sarah J [Medical Imaging Optimisation and Perception Group (MIOPeG), Discipline of Medical Radiation Sciences, Faculty of Health Science, University of Sydney, Sydney, New South Wales (Australia); Moran, Bernadette [Department of Clinical Medicine, Trinity College, Dublin (Ireland); Robinson, John [Medical Imaging Optimisation and Perception Group (MIOPeG), Discipline of Medical Radiation Sciences, Faculty of Health Science, University of Sydney, Sydney, New South Wales (Australia)

    2014-06-15

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

  7. Effect of vertical angulation to dose of thyroid glands in periapical radiography

    Hosoi, Keitaro; Satoh, Keiji; Furumoto, Keiichi (Nippon Dental Univ., Tokyo (Japan). School of Dentistry)

    1992-10-01

    Much attention has been given to reducing the dose of radiation in dental radiography in terms of the highest risk for the head and neck. Organ doses in intraoral radiography vary greatly with subtle differences in vertical angulation. Quantitative determination of doses delivered to the thyroid gland is thus necessary in determining adequate doses and risk for dental radiography. A personal computer program, prepared for estimating organ doses under various radiographic conditions, was used to evaluate the effect of vertical angulation on the dose delivered to the thyroid gland in radiography of the maxillary and mandibular incisors. Review of the literature revealed that the calculated dose delivered to the thyroid gland is approximately in accordance with the data of the actual determination under the same radiographic conditions. The dose-dependence of radiation delivered to the thyroid gland on vertical angulation of the maxilla was much more than that of the mandible. In the mandible, the dose delivered to the thyroid gland increased about three fold at a field size of 6 cm[phi] and about 1.5 fold at 8 cm[phi] when the vertical angulation changed from -40deg to 0deg. In the maxilla, the delivered dose increased about 480 times at a field size of 6 cm[phi] when vertical angulation changed from 0deg to 50deg and rapidly increased about 280 times at 8 cm[phi] when the angulation changed from 0deg to 40deg. The dose of radiation delivered to the thyroid gland was evaluated as a function of product of the irradiated volume within the primary beam directed at the thyroid gland and the inverse square of the distance between a subject's surface and the thyroid gland. (N.K.).

  8. A computational clonal analysis of the developing mouse limb bud.

    Luciano Marcon

    Full Text Available A comprehensive spatio-temporal description of the tissue movements underlying organogenesis would be an extremely useful resource to developmental biology. Clonal analysis and fate mappings are popular experiments to study tissue movement during morphogenesis. Such experiments allow cell populations to be labeled at an early stage of development and to follow their spatial evolution over time. However, disentangling the cumulative effects of the multiple events responsible for the expansion of the labeled cell population is not always straightforward. To overcome this problem, we develop a novel computational method that combines accurate quantification of 2D limb bud morphologies and growth modeling to analyze mouse clonal data of early limb development. Firstly, we explore various tissue movements that match experimental limb bud shape changes. Secondly, by comparing computational clones with newly generated mouse clonal data we are able to choose and characterize the tissue movement map that better matches experimental data. Our computational analysis produces for the first time a two dimensional model of limb growth based on experimental data that can be used to better characterize limb tissue movement in space and time. The model shows that the distribution and shapes of clones can be described as a combination of anisotropic growth with isotropic cell mixing, without the need for lineage compartmentalization along the AP and PD axis. Lastly, we show that this comprehensive description can be used to reassess spatio-temporal gene regulations taking tissue movement into account and to investigate PD patterning hypothesis.

  9. Computational analysis of RNA structures with chemical probing data.

    Ge, Ping; Zhang, Shaojie

    2015-06-01

    RNAs play various roles, not only as the genetic codes to synthesize proteins, but also as the direct participants of biological functions determined by their underlying high-order structures. Although many computational methods have been proposed for analyzing RNA structures, their accuracy and efficiency are limited, especially when applied to the large RNAs and the genome-wide data sets. Recently, advances in parallel sequencing and high-throughput chemical probing technologies have prompted the development of numerous new algorithms, which can incorporate the auxiliary structural information obtained from those experiments. Their potential has been revealed by the secondary structure prediction of ribosomal RNAs and the genome-wide ncRNA function annotation. In this review, the existing probing-directed computational methods for RNA secondary and tertiary structure analysis are discussed.

  10. Computer aided analysis, simulation and optimisation of thermal sterilisation processes.

    Narayanan, C M; Banerjee, Arindam

    2013-04-01

    Although thermal sterilisation is a widely employed industrial process, little work is reported in the available literature including patents on the mathematical analysis and simulation of these processes. In the present work, software packages have been developed for computer aided optimum design of thermal sterilisation processes. Systems involving steam sparging, jacketed heating/cooling, helical coils submerged in agitated vessels and systems that employ external heat exchangers (double pipe, shell and tube and plate exchangers) have been considered. Both batch and continuous operations have been analysed and simulated. The dependence of del factor on system / operating parameters such as mass or volume of substrate to be sterilised per batch, speed of agitation, helix diameter, substrate to steam ratio, rate of substrate circulation through heat exchanger and that through holding tube have been analysed separately for each mode of sterilisation. Axial dispersion in the holding tube has also been adequately accounted for through an appropriately defined axial dispersion coefficient. The effect of exchanger characteristics/specifications on the system performance has also been analysed. The multiparameter computer aided design (CAD) software packages prepared are thus highly versatile in nature and they permit to make the most optimum choice of operating variables for the processes selected. The computed results have been compared with extensive data collected from a number of industries (distilleries, food processing and pharmaceutical industries) and pilot plants and satisfactory agreement has been observed between the two, thereby ascertaining the accuracy of the CAD softwares developed. No simplifying assumptions have been made during the analysis and the design of associated heating / cooling equipment has been performed utilising the most updated design correlations and computer softwares.

  11. Quantitative shadowgraphy and proton radiography for large intensity modulations

    Kasim, Muhammad Firmansyah; Ceurvorst, Luke; Ratan, Naren; Sadler, James; Chen, Nicholas; Sävert, Alexander; Trines, Raoul; Bingham, Robert; Burrows, Philip N.; Kaluza, Malte C.; Norreys, Peter

    2017-02-01

    Shadowgraphy is a technique widely used to diagnose objects or systems in various fields in physics and engineering. In shadowgraphy, an optical beam is deflected by the object and then the intensity modulation is captured on a screen placed some distance away. However, retrieving quantitative information from the shadowgrams themselves is a challenging task because of the nonlinear nature of the process. Here, we present a method to retrieve quantitative information from shadowgrams, based on computational geometry. This process can also be applied to proton radiography for electric and magnetic field diagnosis in high-energy-density plasmas and has been benchmarked using a toroidal magnetic field as the object, among others. It is shown that the method can accurately retrieve quantitative parameters with error bars less than 10%, even when caustics are present. The method is also shown to be robust enough to process real experimental results with simple pre- and postprocessing techniques. This adds a powerful tool for research in various fields in engineering and physics for both techniques.

  12. Measuring and correcting wobble in large-scale transmission radiography

    Rogers, Thomas W; Morton, Edward J; Griffin, Lewis D

    2016-01-01

    Large-scale transmission radiography scanners are used to image vehicles and cargo containers. Acquired images are inspected for threats by a human operator or a computer algorithm. To make accurate detections, it is important that image values are precise. However, due to the scale of such systems, they can be mechanically unstable, causing the imaging array to wobble during a scan. This leads to an effective loss of precision in the captured image. We consider the measurement of wobble and amelioration of the consequent loss of image precision. Following our previous work, we use Beam Position Detectors (BPDs) to measure the cross-sectional profile of the X-ray beam, allowing for estimation, and thus correction of wobble. We propose: (i) a model of image formation with a wobbling detector array; (ii) a method of wobble correction derived from this model; (iii) methods for calibrating sensor sensitivities and relative offsets; (iv) a Random Regression Forest based method for instantaneous estimation of detec...

  13. Analysis and computational dissection of molecular signature multiplicity.

    Alexander Statnikov

    2010-05-01

    Full Text Available Molecular signatures are computational or mathematical models created to diagnose disease and other phenotypes and to predict clinical outcomes and response to treatment. It is widely recognized that molecular signatures constitute one of the most important translational and basic science developments enabled by recent high-throughput molecular assays. A perplexing phenomenon that characterizes high-throughput data analysis is the ubiquitous multiplicity of molecular signatures. Multiplicity is a special form of data analysis instability in which different analysis methods used on the same data, or different samples from the same population lead to different but apparently maximally predictive signatures. This phenomenon has far-reaching implications for biological discovery and development of next generation patient diagnostics and personalized treatments. Currently the causes and interpretation of signature multiplicity are unknown, and several, often contradictory, conjectures have been made to explain it. We present a formal characterization of signature multiplicity and a new efficient algorithm that offers theoretical guarantees for extracting the set of maximally predictive and non-redundant signatures independent of distribution. The new algorithm identifies exactly the set of optimal signatures in controlled experiments and yields signatures with significantly better predictivity and reproducibility than previous algorithms in human microarray gene expression datasets. Our results shed light on the causes of signature multiplicity, provide computational tools for studying it empirically and introduce a framework for in silico bioequivalence of this important new class of diagnostic and personalized medicine modalities.

  14. Computing the surveillance error grid analysis: procedure and examples.

    Kovatchev, Boris P; Wakeman, Christian A; Breton, Marc D; Kost, Gerald J; Louie, Richard F; Tran, Nam K; Klonoff, David C

    2014-07-01

    The surveillance error grid (SEG) analysis is a tool for analysis and visualization of blood glucose monitoring (BGM) errors, based on the opinions of 206 diabetes clinicians who rated 4 distinct treatment scenarios. Resulting from this large-scale inquiry is a matrix of 337 561 risk ratings, 1 for each pair of (reference, BGM) readings ranging from 20 to 580 mg/dl. The computation of the SEG is therefore complex and in need of automation. The SEG software introduced in this article automates the task of assigning a degree of risk to each data point for a set of measured and reference blood glucose values so that the data can be distributed into 8 risk zones. The software's 2 main purposes are to (1) distribute a set of BG Monitor data into 8 risk zones ranging from none to extreme and (2) present the data in a color coded display to promote visualization. Besides aggregating the data into 8 zones corresponding to levels of risk, the SEG computes the number and percentage of data pairs in each zone and the number/percentage of data pairs above/below the diagonal line in each zone, which are associated with BGM errors creating risks for hypo- or hyperglycemia, respectively. To illustrate the action of the SEG software we first present computer-simulated data stratified along error levels defined by ISO 15197:2013. This allows the SEG to be linked to this established standard. Further illustration of the SEG procedure is done with a series of previously published data, which reflect the performance of BGM devices and test strips under various environmental conditions. We conclude that the SEG software is a useful addition to the SEG analysis presented in this journal, developed to assess the magnitude of clinical risk from analytically inaccurate data in a variety of high-impact situations such as intensive care and disaster settings.

  15. How to create a degree course in radiography: a recipe

    Pratt, S. E-mail: Pratt@cf.ac.uk; Adams, C. E-mail: AdamsC1@cf.ac.uk

    2003-11-01

    This article explains how an undergraduate programme is devised and validated. Since 1993, all courses in radiography have been of graduate level with radiography education being based in higher educational institutions. Before a new degree is implemented a review of the existing programme is undertaken. The proposed degree philosophy and learning outcomes need to be determined before the content; its mode of delivery and assessment are developed. Input from stakeholders (such as clinical colleagues) is necessary as well as adherence to policies and strategies for radiography education. Throughout the development process compliance with policy, both national and local, is critical. All radiography programmes have to be validated/accredited by representatives from national organisations--such as The Society and College of Radiographers (SCoR). These representatives scrutinise the proposed degree course documentation; often they may also inspect the clinical and university facilities in which the education and training will take place.

  16. Modern EMC analysis I time-domain computational schemes

    Kantartzis, Nikolaos V

    2008-01-01

    The objective of this two-volume book is the systematic and comprehensive description of the most competitive time-domain computational methods for the efficient modeling and accurate solution of contemporary real-world EMC problems. Intended to be self-contained, it performs a detailed presentation of all well-known algorithms, elucidating on their merits or weaknesses, and accompanies the theoretical content with a variety of applications. Outlining the present volume, the analysis covers the theory of the finite-difference time-domain, the transmission-line matrix/modeling, and the finite i

  17. Vortex dominated flows. Analysis and computation for multiple scale phenomena

    Ting, L. [New York Univ., NY (United States). Courant Inst. of Mathematical Sciences; Klein, R. [Freie Univ. Berlin (Germany). Fachbereich Mathematik und Informatik; Knio, O.M. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Mechanical Engineering

    2007-07-01

    This monograph provides in-depth analyses of vortex dominated flows via matched and multiscale asymptotics, and demonstrates how insight gained through these analyses can be exploited in the construction of robust, efficient, and accurate numerical techniques. The book explores the dynamics of slender vortex filaments in detail, including fundamental derivations, compressible core structure, weakly non-linear limit regimes, and associated numerical methods. Similarly, the volume covers asymptotic analysis and computational techniques for weakly compressible flows involving vortex-generated sound and thermoacoustics. The book is addressed to both graduate students and researchers. (orig.)

  18. Computational geometry assessment for morphometric analysis of the mandible.

    Raith, Stefan; Varga, Viktoria; Steiner, Timm; Hölzle, Frank; Fischer, Horst

    2017-01-01

    This paper presents a fully automated algorithm for geometry assessment of the mandible. Anatomical landmarks could be reliably detected and distances were statistically evaluated with principal component analysis. The method allows for the first time to generate a mean mandible shape with statistically valid geometrical variations based on a large set of 497 CT-scans of human mandibles. The data may be used in bioengineering for designing novel oral implants, for planning of computer-guided surgery, and for the improvement of biomechanical models, as it is shown that commercially available mandible replicas differ significantly from the mean of the investigated population.

  19. Parameter estimation and error analysis in environmental modeling and computation

    Kalmaz, E. E.

    1986-01-01

    A method for the estimation of parameters and error analysis in the development of nonlinear modeling for environmental impact assessment studies is presented. The modular computer program can interactively fit different nonlinear models to the same set of data, dynamically changing the error structure associated with observed values. Parameter estimation techniques and sequential estimation algorithms employed in parameter identification and model selection are first discussed. Then, least-square parameter estimation procedures are formulated, utilizing differential or integrated equations, and are used to define a model for association of error with experimentally observed data.

  20. Computational issue in the analysis of adaptive control systems

    Kosut, Robert L.

    1989-01-01

    Adaptive systems under slow parameter adaption can be analyzed by the method of averaging. This provides a means to assess stability (and instability) properties of most adaptive systems, either continuous-time or (more importantly for practice) discrete-time, as well as providing an estimate of the region of attraction. Although the method of averaging is conceptually straightforward, even simple examples are well beyond hand calculations. Specific software tools are proposed which can provide the basis for user-friendly environment to perform the necessary computations involved in the averaging analysis.

  1. Error analysis in correlation computation of single particle reconstruction technique

    胡悦; 隋森芳

    1999-01-01

    The single particle reconstruction technique has become particularly important in the structure analysis of hiomaeromolecules. The problem of reconstructing a picture from identical samples polluted by colored noises is studied, and the alignment error in the correlation computation of single particle reconstruction technique is analyzed systematically. The concept of systematic error is introduced, and the explicit form of the systematic error is given under the weak noise approximation. The influence of the systematic error on the reconstructed picture is discussed also, and an analytical formula for correcting the distortion in the picture reconstruction is obtained.

  2. Spatial Analysis Along Networks Statistical and Computational Methods

    Okabe, Atsuyuki

    2012-01-01

    In the real world, there are numerous and various events that occur on and alongside networks, including the occurrence of traffic accidents on highways, the location of stores alongside roads, the incidence of crime on streets and the contamination along rivers. In order to carry out analyses of those events, the researcher needs to be familiar with a range of specific techniques. Spatial Analysis Along Networks provides a practical guide to the necessary statistical techniques and their computational implementation. Each chapter illustrates a specific technique, from Stochastic Point Process

  3. Analysis of Network Performance for Computer Communication Systems with Benchmark

    2000-01-01

    This paper introduced a performance evaluating approach of computer communication system based on the simulation and measurement technology, and discussed its evaluating models. The result of our experiment showed that the outcome of practical measurement on Ether-LAN fitted in well with the theoreticai analysis. The approach we presented can be used to define various kinds of artificially simulated load models conveniently, build all kinds of network application environments in a flexible way, and exert sufficientiy the widely-used and high-precision features of the traditional simulation technology and the reality,reliability, adaptability features of measurement technology.

  4. Diagnosis of Nasopharyngeal Obstruction by Lateral Cephalometric Radiography

    H. Ravanmehr

    2005-06-01

    Full Text Available Statement of Problem: Nasopharyngeal obstruction by adenoid enlargement is one of the main causes of mouth breathing. Diagnostic indices of nasopharyngeal obstruction by lateral cephalometric radiography are controversial.Purpose: The purpose of this study was to diagnose the nasopharyngeal obstruction by means of lateral cephalometric radiography.Materials and Methods: In this research two groups, (study and control, of 6 to 15 years old were studied. In the study group, 46 mouth breathers were clinically examined by an orthodontist and an Otolaryngologist to confirm the nasopharyngeal obstruction.Control group was also comprised of 46 nasal breathers within the same age groups. A lateral cephalogram in centric occlusion was obtained for each patient. After tracing,following 7 nasopharyngeal variables were measured: 1- pp (palatopharyngeal depth.2- Ad.Pmp (nasopharyngeal airway depth. 3- Air area (nasopharyngeal airway area. 4-NP area (bony area of nasopharynx. 5- Ba.Pmp (bony depth of nasopharynx. 6- d(bony depth of nasopharynx. 7- h (bony height of nasopharynx.Statistical t-test was conducted following calculating the mean, standard deviation and p-value of parameters. Discriminant function analysis was employed subsequent to thet-test for the significant variables, in order to find a method by which the values for several variables could be used simultaneously to determine whether obstruction exists.Qualitative variables of sex and age groups (6-10, 11-12, and 13-15 years old were alsoused in discriminant analysis.Results: In the study group, mean value of pp, Ad.pmp, air area, Np area and Ba.pmp were significantly decreased, whereas mean of d and h variables were not considerably lessened. After performing analysis stage, the following discriminant function equationwith critical point of 3.88 and correct classification of 94.57% was determined:D=0.345 (pp +0.064 (Ad.pmp-0.001(NP area + 0.03(Air area +0.505(Age1.If a person’s age is

  5. 200 MeV proton radiography studies with a hand phantom using a prototype proton CT scanner.

    Plautz, Tia; Bashkirov, V; Feng, V; Hurley, F; Johnson, R P; Leary, C; Macafee, S; Plumb, A; Rykalin, V; Sadrozinski, H F-W; Schubert, K; Schulte, R; Schultze, B; Steinberg, D; Witt, M; Zatserklyaniy, A

    2014-04-01

    Proton radiography has applications in patient alignment and verification procedures for proton beam radiation therapy. In this paper, we report an experiment which used 200 MeV protons to generate proton energy-loss and scattering radiographs of a hand phantom. The experiment used the first-generation proton computed tomography (CT) scanner prototype, which was installed on the research beam line of the clinical proton synchrotron at Loma Linda University Medical Center. It was found that while both radiographs displayed anatomical details of the hand phantom, the energy-loss radiograph had a noticeably higher resolution. Nonetheless, scattering radiography may yield more contrast between soft and bone tissue than energy-loss radiography, however, this requires further study. This study contributes to the optimization of the performance of the next-generation of clinical proton CT scanners. Furthermore, it demonstrates the potential of proton imaging (proton radiography and CT), which is now within reach of becoming available as a new, potentially low-dose medical imaging modality.

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

    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.

  7. Plans for a sensitivity analysis of bridge-scour computations

    Dunn, David D.; Smith, Peter N.

    1993-01-01

    Plans for an analysis of the sensitivity of Level 2 bridge-scour computations are described. Cross-section data from 15 bridge sites in Texas are modified to reflect four levels of field effort ranging from no field surveys to complete surveys. Data from United States Geological Survey (USGS) topographic maps will be used to supplement incomplete field surveys. The cross sections are used to compute the water-surface profile through each bridge for several T-year recurrence-interval design discharges. The effect of determining the downstream energy grade-line slope from topographic maps is investigated by systematically varying the starting slope of each profile. The water-surface profile analyses are then used to compute potential scour resulting from each of the design discharges. The planned results will be presented in the form of exceedance-probability versus scour-depth plots with the maximum and minimum scour depths at each T-year discharge presented as error bars.

  8. Applying DNA computation to intractable problems in social network analysis.

    Chen, Rick C S; Yang, Stephen J H

    2010-09-01

    From ancient times to the present day, social networks have played an important role in the formation of various organizations for a range of social behaviors. As such, social networks inherently describe the complicated relationships between elements around the world. Based on mathematical graph theory, social network analysis (SNA) has been developed in and applied to various fields such as Web 2.0 for Web applications and product developments in industries, etc. However, some definitions of SNA, such as finding a clique, N-clique, N-clan, N-club and K-plex, are NP-complete problems, which are not easily solved via traditional computer architecture. These challenges have restricted the uses of SNA. This paper provides DNA-computing-based approaches with inherently high information density and massive parallelism. Using these approaches, we aim to solve the three primary problems of social networks: N-clique, N-clan, and N-club. Their accuracy and feasible time complexities discussed in the paper will demonstrate that DNA computing can be used to facilitate the development of SNA.

  9. Computational analysis of light scattering from collagen fiber networks

    Arifler, Dizem; Pavlova, Ina; Gillenwater, Ann; Richards-Kortum, Rebecca

    2007-07-01

    Neoplastic progression in epithelial tissues is accompanied by structural and morphological changes in the stromal collagen matrix. We used the Finite-Difference Time-Domain (FDTD) method, a popular computational technique for full-vector solution of complex problems in electromagnetics, to establish a relationship between structural properties of collagen fiber networks and light scattering, and to analyze how neoplastic changes alter stromal scattering properties. To create realistic collagen network models, we acquired optical sections from the stroma of fresh normal and neoplastic oral cavity biopsies using fluorescence confocal microscopy. These optical sections were then processed to construct three-dimensional collagen networks of different sizes as FDTD model input. Image analysis revealed that volume fraction of collagen fibers in the stroma decreases with neoplastic progression, and statistical texture features computed suggest that fibers tend to be more disconnected in neoplastic stroma. The FDTD modeling results showed that neoplastic fiber networks have smaller scattering cross-sections compared to normal networks of the same size, whereas high-angle scattering probabilities tend to be higher for neoplastic networks. Characterization of stromal scattering is expected to provide a basis to better interpret spectroscopic optical signals and to develop more reliable computational models to describe photon propagation in epithelial tissues.

  10. Analysis of CERN computing infrastructure and monitoring data

    Nieke, C.; Lassnig, M.; Menichetti, L.; Motesnitsalis, E.; Duellmann, D.

    2015-12-01

    Optimizing a computing infrastructure on the scale of LHC requires a quantitative understanding of a complex network of many different resources and services. For this purpose the CERN IT department and the LHC experiments are collecting a large multitude of logs and performance probes, which are already successfully used for short-term analysis (e.g. operational dashboards) within each group. The IT analytics working group has been created with the goal to bring data sources from different services and on different abstraction levels together and to implement a suitable infrastructure for mid- to long-term statistical analysis. It further provides a forum for joint optimization across single service boundaries and the exchange of analysis methods and tools. To simplify access to the collected data, we implemented an automated repository for cleaned and aggregated data sources based on the Hadoop ecosystem. This contribution describes some of the challenges encountered, such as dealing with heterogeneous data formats, selecting an efficient storage format for map reduce and external access, and will describe the repository user interface. Using this infrastructure we were able to quantitatively analyze the relationship between CPU/wall fraction, latency/throughput constraints of network and disk and the effective job throughput. In this contribution we will first describe the design of the shared analysis infrastructure and then present a summary of first analysis results from the combined data sources.

  11. The analysis of gastric function using computational techniques

    Young, P

    2002-01-01

    The work presented in this thesis was carried out at the Magnetic Resonance Centre, Department of Physics and Astronomy, University of Nottingham, between October 1996 and June 2000. This thesis describes the application of computerised techniques to the analysis of gastric function, in relation to Magnetic Resonance Imaging data. The implementation of a computer program enabling the measurement of motility in the lower stomach is described in Chapter 6. This method allowed the dimensional reduction of multi-slice image data sets into a 'Motility Plot', from which the motility parameters - the frequency, velocity and depth of contractions - could be measured. The technique was found to be simple, accurate and involved substantial time savings, when compared to manual analysis. The program was subsequently used in the measurement of motility in three separate studies, described in Chapter 7. In Study 1, four different meal types of varying viscosity and nutrient value were consumed by 12 volunteers. The aim of...

  12. Dynamic analysis of spur gears using computer program DANST

    Oswald, Fred B.; Lin, Hsiang H.; Liou, Chuen-Huei; Valco, Mark J.

    1993-06-01

    DANST is a computer program for static and dynamic analysis of spur gear systems. The program can be used for parametric studies to predict the effect on dynamic load and tooth bending stress of spur gears due to operating speed, torque, stiffness, damping, inertia, and tooth profile. DANST performs geometric modeling and dynamic analysis for low- or high-contact-ratio spur gears. DANST can simulate gear systems with contact ratio ranging from one to three. It was designed to be easy to use, and it is extensively documented by comments in the source code. This report describes the installation and use of DANST. It covers input data requirements and presents examples. The report also compares DANST predictions for gear tooth loads and bending stress to experimental and finite element results.

  13. Critical Data Analysis Precedes Soft Computing Of Medical Data

    Keyserlingk, Diedrich Graf von; Jantzen, Jan; Berks, G.

    2000-01-01

    extracted. The factors had different relationships (loadings) to the symptoms. Although the factors were gained only by computations, they seemed to express some modular features of the language disturbances. This phenomenon, that factors represent superior aspects of data, is well known in factor analysis....... Factor I mediates the overall severity of the disturbance, factor II points to expressive versus comprehensive character of the language disorder, factor III represents the granularity of the phonetic mistakes, factor IV accentuates the patients' awareness of his disease, and factor V exposes...... the deficits in communication. Sets of symptoms corresponding to the traditional symptoms in Broca and Wernicke aphasia may be represented in the factors, but the factor itself does not represent a syndrome. It is assumed that this kind of data analysis shows a new approach to the understanding of language...

  14. Analysis on Phase Transformation (ATP) Using Computational Thermal Principles (CTP)

    N.Alagurmurthi; K.Palaniradja; V. Soundararajan

    2004-01-01

    Computer analysis based on computational thermal principles to predict the transformation kinetics in steels at varying temperatures is of great practical importance in different areas of heat treatment. As a result, using the theory of transient state heat conduction with convective boundary conditions, an efficient program named "ATP" (Analysis on Phase Transformation) has been developed to determine the temperature distribution under different quenching conditions for different geometries such as plate, cylinder and sphere. In addition to these the microstructures and the corresponding hardness developed during quenching are predicted using Time Temperature Transformation (TTT) diagram incorporated in the analysis. To approve our work, dilation curves, Heisler charts and time-temperature history curve have been generated. This paper deals with basic objective of the program (ATP) determination of temperature, microstructure and hardness distribution and also includes an online prediction of austenite-pearlite and austenite-martensite transformation in steels along with the corresponding retained fractions. The quenching of a cylinder in gases, liquids and liquid metals is analyzed to show the non-liner effect of cylinder diameter on the temperature and microstructures. Further in the program we have considered a typical 1080 steel cylinders quenched in water for predicting and comparing the program results with experimental values and can be extended even to other grades of steels. The numerical results of program are found to be in good agreement with the experimental data obtained. Finally the quenching process analysis described in the study appears to be a promising tool for the design of heat-treatment process parameters for steels.

  15. The CDF Computing and Analysis System:First Experience

    RickColombo; FedorRatnikov; 等

    2001-01-01

    The Collider Detector at Fermilab(CDF) collaboration records and analyses proton anti-proton interactions with a center-of -mass energy of 2 TeV at the Tevatron,A new collider run,Run II,of the Tevatron started in April.During its more than two year duration the CDF experiment expects to record about 1 PetaByte of data.With its multi-purpose detector and center-of mass energy at the frontier,the experimental program is large and versatile.The over 500 scientists of CDF will engage in searches for new particles,like the Higgs boson or supersymmetric particles,precision measurement of electroweak parameters,like the mass of the W boson,measurement of top quark parameters and a large spectrum of B physics.The experiment has taken data and analysed them in previous runs.For Run II,however,the computing model was changed to incorporate new methodologies.the file format switched.and both data handling and analysis system redesigned to cope with the increased demands.This paper(4-036 at Chep 2001)gives an overview of the CDF Run II compute system with emphasize on areas where the current system does not match initial estimates and projections.For the data handling and analysis system a more detailed description is given.

  16. Wind energy conversion system analysis model (WECSAM) computer program documentation

    Downey, W T; Hendrick, P L

    1982-07-01

    Described is a computer-based wind energy conversion system analysis model (WECSAM) developed to predict the technical and economic performance of wind energy conversion systems (WECS). The model is written in CDC FORTRAN V. The version described accesses a data base containing wind resource data, application loads, WECS performance characteristics, utility rates, state taxes, and state subsidies for a six state region (Minnesota, Michigan, Wisconsin, Illinois, Ohio, and Indiana). The model is designed for analysis at the county level. The computer model includes a technical performance module and an economic evaluation module. The modules can be run separately or together. The model can be run for any single user-selected county within the region or looped automatically through all counties within the region. In addition, the model has a restart capability that allows the user to modify any data-base value written to a scratch file prior to the technical or economic evaluation. Thus, any user-supplied data for WECS performance, application load, utility rates, or wind resource may be entered into the scratch file to override the default data-base value. After the model and the inputs required from the user and derived from the data base are described, the model output and the various output options that can be exercised by the user are detailed. The general operation is set forth and suggestions are made for efficient modes of operation. Sample listings of various input, output, and data-base files are appended. (LEW)

  17. Computational Particle Physics for Event Generators and Data Analysis

    Perret-Gallix, Denis

    2013-01-01

    High-energy physics data analysis relies heavily on the comparison between experimental and simulated data as stressed lately by the Higgs search at LHC and the recent identification of a Higgs-like new boson. The first link in the full simulation chain is the event generation both for background and for expected signals. Nowadays event generators are based on the automatic computation of matrix element or amplitude for each process of interest. Moreover, recent analysis techniques based on the matrix element likelihood method assign probabilities for every event to belong to any of a given set of possible processes. This method originally used for the top mass measurement, although computing intensive, has shown its power at LHC to extract the new boson signal from the background. Serving both needs, the automatic calculation of matrix element is therefore more than ever of prime importance for particle physics. Initiated in the eighties, the techniques have matured for the lowest order calculations (tree-le...

  18. Efficiency of neutron radiography in nondestructive materials testing. Final report. Die Leistungsfaehigkeit der Neutronenradiographie in der zerstoerungsfreien Werkstoffpruefung. Abschlussbericht

    Mast, H.U.; Stein, P.; Brandler, T.; Richter, R. (Industrieanlagen-Betriebsgesellschaft mbH, Ottobrunn (Germany, F.R.)); Daum, W.; Heidt, H.; Stade, J.; Teichert, H.D. (Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany, F.R.)); Greim, L.; Wrobel, M. (GKSS-Forschungszentrum Geesthacht GmbH, Geesthacht-Tesperhude (Germany, F.R.)); Schatz, A.; Pfister, G. (Stuttgart Univ. (Germany, F.R.).

    1989-07-31

    The performance of neutron radiography and neutron computer tomography was investigated in comparison to that of conventional nondestructive testing methods. Neutron radiography was shown to be superior with respect to the detection of certain flaws in nonmetallic materials, e.g. ceramics and carbon fiber reinforced epoxy resin, and nonmetallic components, e.g. adhesives, seals and potting compounds, especially behind or between metallic layers. Furthermore, image processing techniques were developed with regard to the automated evaluation of radiographs as well as, on the basis of the determined resolution functions, to the reduction of radiograph unsharpness by deconvolution of the point-spread-function. The technique of neutron computer-tomography was developed further and the improvment obtained by introducing a fan-beam geometry was demonstrated. (orig.).

  19. COMPUTING

    M. Kasemann

    CMS relies on a well functioning, distributed computing infrastructure. The Site Availability Monitoring (SAM) and the Job Robot submission have been very instrumental for site commissioning in order to increase availability of more sites such that they are available to participate in CSA07 and are ready to be used for analysis. The commissioning process has been further developed, including "lessons learned" documentation via the CMS twiki. Recently the visualization, presentation and summarizing of SAM tests for sites has been redesigned, it is now developed by the central ARDA project of WLCG. Work to test the new gLite Workload Management System was performed; a 4 times increase in throughput with respect to LCG Resource Broker is observed. CMS has designed and launched a new-generation traffic load generator called "LoadTest" to commission and to keep exercised all data transfer routes in the CMS PhE-DEx topology. Since mid-February, a transfer volume of about 12 P...

  20. Multiscale analysis of nonlinear systems using computational homology

    Konstantin Mischaikow, Rutgers University/Georgia Institute of Technology, Michael Schatz, Georgia Institute of Technology, William Kalies, Florida Atlantic University, Thomas Wanner,George Mason University

    2010-05-19

    This is a collaborative project between the principal investigators. However, as is to be expected, different PIs have greater focus on different aspects of the project. This report lists these major directions of research which were pursued during the funding period: (1) Computational Homology in Fluids - For the computational homology effort in thermal convection, the focus of the work during the first two years of the funding period included: (1) A clear demonstration that homology can sensitively detect the presence or absence of an important flow symmetry, (2) An investigation of homology as a probe for flow dynamics, and (3) The construction of a new convection apparatus for probing the effects of large-aspect-ratio. (2) Computational Homology in Cardiac Dynamics - We have initiated an effort to test the use of homology in characterizing data from both laboratory experiments and numerical simulations of arrhythmia in the heart. Recently, the use of high speed, high sensitivity digital imaging in conjunction with voltage sensitive fluorescent dyes has enabled researchers to visualize electrical activity on the surface of cardiac tissue, both in vitro and in vivo. (3) Magnetohydrodynamics - A new research direction is to use computational homology to analyze results of large scale simulations of 2D turbulence in the presence of magnetic fields. Such simulations are relevant to the dynamics of black hole accretion disks. The complex flow patterns from simulations exhibit strong qualitative changes as a function of magnetic field strength. Efforts to characterize the pattern changes using Fourier methods and wavelet analysis have been unsuccessful. (4) Granular Flow - two experts in the area of granular media are studying 2D model experiments of earthquake dynamics where the stress fields can be measured; these stress fields from complex patterns of 'force chains' that may be amenable to analysis using computational homology. (5) Microstructure

  1. Multiscale analysis of nonlinear systems using computational homology

    Konstantin Mischaikow; Michael Schatz; William Kalies; Thomas Wanner

    2010-05-24

    This is a collaborative project between the principal investigators. However, as is to be expected, different PIs have greater focus on different aspects of the project. This report lists these major directions of research which were pursued during the funding period: (1) Computational Homology in Fluids - For the computational homology effort in thermal convection, the focus of the work during the first two years of the funding period included: (1) A clear demonstration that homology can sensitively detect the presence or absence of an important flow symmetry, (2) An investigation of homology as a probe for flow dynamics, and (3) The construction of a new convection apparatus for probing the effects of large-aspect-ratio. (2) Computational Homology in Cardiac Dynamics - We have initiated an effort to test the use of homology in characterizing data from both laboratory experiments and numerical simulations of arrhythmia in the heart. Recently, the use of high speed, high sensitivity digital imaging in conjunction with voltage sensitive fluorescent dyes has enabled researchers to visualize electrical activity on the surface of cardiac tissue, both in vitro and in vivo. (3) Magnetohydrodynamics - A new research direction is to use computational homology to analyze results of large scale simulations of 2D turbulence in the presence of magnetic fields. Such simulations are relevant to the dynamics of black hole accretion disks. The complex flow patterns from simulations exhibit strong qualitative changes as a function of magnetic field strength. Efforts to characterize the pattern changes using Fourier methods and wavelet analysis have been unsuccessful. (4) Granular Flow - two experts in the area of granular media are studying 2D model experiments of earthquake dynamics where the stress fields can be measured; these stress fields from complex patterns of 'force chains' that may be amenable to analysis using computational homology. (5) Microstructure

  2. Occlusal caries detection with KaVo DIAGNOdent and radiography: an in vitro comparison.

    Shi, X Q; Welander, U; Angmar-Månsson, B

    2000-01-01

    A new laser fluorescence method, KaVo DIAGNOdent, was tested with respect to reproducibility and validity and compared with radiography regarding accuracy in the detection of occlusal caries. Seventy-six extracted premolar and molar teeth were measured twice with DIAGNOdent under both wet and dry conditions, at an interval of 2 weeks. Conventional film radiographs were exposed. Microradiographic analysis of sections of the teeth served as the gold standard. Intra-class correlation coefficient and Pearson's correlation coefficient were used to assess the reproducibility and the validity of the method, respectively. The influence of time and varying humidities on DIAGNOdent readings were analysed by two-way repeated measure ANOVA. ROC curves were plotted for DIAGNOdent readings and radiographic registration of caries by 6 observers, and the areas under the curves were compared using Student's t test. Under both wet and dry conditions, the reproducibility of the DIAGNOdent method was excellent: R = 0.97 and 0.96, respectively. The diagnostic accuracy of DIAGNOdent was significantly better than that of radiography (pDIAGNOdent method was superior to that of radiography.

  3. Diagnostic Accuracy of Ultrasonography and Radiography in Initial Evaluation of Chest Trauma Patients

    Ali Vafaei

    2016-01-01

    Full Text Available Introduction: Application of chest radiography for all multiple trauma patients is associated with a significant increase in total costs, exposure to radiation, and overcrowding of the emergency department. Ultrasound has been introduced as an alternative diagnostic tool in this regard. The aim of the present study is to compare the diagnostic accuracy of chest ultrasonography and radiography in detection of traumatic intrathoracic injuries. Methods: In the present prospective cross-sectional study, patients with traumatic intrathoracic injuries, who were referred to the emergency department from December 2013 to December 2014, were assessed. The patients underwent bedside ultrasound, radiographic and computed tomography (CT scan examinations based on ATLS recommendations. Screening performance characteristics of ultrasonography and radiography were compared using SPSS 21.0. Chest CT scan was considered as gold standard. Results: 152 chest trauma patients with a mean age of 31.4 ± 13.8 years (range: 4 ‒ 67, were enrolled (77.6% male. Chest CT scan showed pulmonary contusion in 48 (31.6% patients, hemothorax in 29 (19.1%, and pneumothorax in 55 (36.2% cases. Area under the ROC curve of ultrasonography in detection of pneumothorax, hemothorax, and pulmonary contusion were 0.91 (95% CI: 0.86‒0.96, 0.86 (95% CI: 0.78‒0.94, and 0.80 (95% CI: 0.736‒0.88, respectively. Area under the ROC curve of radiography was 0.80 (95% CI: 0.736‒0.87 for detection of pneumothorax, 0.77 (95% CI: 0.68‒0.86 for hemothorax, and 0.58 (95% CI: 0.5‒0.67 for pulmonary contusion. Comparison of areas under the ROC curve declared the significant superiority of ultrasonography in detection of pneumothorax (p = 0.02 and pulmonary contusion (p < 0.001. However, the diagnostic value of the two tests was equal in detection of hemothorax (p = 0.08. Conclusion: The results of the present study showed that ultrasonography is preferable to radiography in the initial

  4. Image quality and exposure dose in digital projection radiography; Bildqualitaet und Dosis in der Digitalen Projektionsradiographie

    Busch, H.P.; Busch, S.; Decker, C.; Schilz, C. [Krankenhaus der Barmherzigen Brueder Trier, Abt. fuer Radiologie, Trier (Germany)

    2003-01-01

    Purpose: Comparison of the imaging capabilities of storage phosphor (computed) radiography and flat plate radiography with conventional film-screen radiography to find new strategies for quality and dose management, i.e., optimizing imaging quality and dose depending on the imaging method and clinical situation. Materials and Methods: Images of a CDRAD-phantom, hand-phantom, abdomen-phantom and chest-phantom obtained with different exposure voltages (50 kV, 73 kV, 109 kV) and different speeds (200, 400, 800, 1600) were processed with various digital systems (flat plate detector: Digital Diagnost [Philips]; storage phosphors: ADC-70 [Agfa], ADC-Solo [Agfa], FCR XG 1 [Fuji]) and a conventional film-screen system (HT100G/Ortho Regular [Agfa]). Results: The evaluation of CDRAD images found the flat plate detector system to have the highest contrast detectability for all dose levels, followed by the FCR XG 1, ADC-Solo and ADC-70 systems. Comparison of the organ-phantom images found the flat plate detector system to be equal to film-screen radiography and especially to storage phosphor systems even for low exposure doses. Conclusions: Flat plate radiography systems demonstrate the highest potential for high image quality when reducing the exposure dose. Depending on the system generation, the storage phosphor systems also show an improved image quality, but the possibility of a dose reduction is limited in comparison with the flat plate detector system. (orig.) [German] Ziel: Die vergleichende Darstellung der Abbildungseigenschaften verschiedener Speicherfoliengeraete und einer Flachdetektoranlage mit Film/Folienaufnahmen kann zu neuen Strategien des Qualitaets- und Dosismanagements fuehren, d.h. zu einer Optimierung von Bildqualitaet und Dosis in Abhaengigkeit von der Untersuchungsmethode und der klinischen Fragestellung. Methode: Aufnahmen von einem CDRAD-Phantom, Handphantom, Abdomenphantom und Thoraxphantom wurden mit verschiedenen digitalen Systemen (Flachdetektor

  5. Monte Carlo simulation on Graphical Processor Unit of the scattered beam in radiography non-destructive testing context

    Tisseur, David; Andrieux, Alexan; Costin, Marius; Vabre, Alexandre

    2014-06-01

    CEA-LIST develops CIVA software for non-destructive testing simulation. Radiography Monte Carlo simulation for the scattered beam can be quite long (several hours) even on a multi-thread CPU implementation. In order to reduce this computation time, we have modified and adapted for CIVA a GPU open source code named MCGPU. This paper presents our work and the results of cross comparison between CIVA and the modified MCGPU code in a NDT context.

  6. High spectral and spatial resolution X-ray transmission radiography and tomography using a Color X-ray Camera

    Boone, Matthieu; Garrevoet, Jan; Tack, Pieter; Scharf, Oliver; Cormode, David P.; Van Loo, Denis; Pauwels, Elin; Dierick, Manuel; Vincze, Laszlo; Van Hoorebeke, Luc

    2013-01-01

    High resolution X-ray radiography and computed tomography are excellent techniques for non-destructive characterization of an object under investigation at a spatial resolution in the micrometer range. However, as the image contrast depends on both chemical composition and material density, no chemical information is obtained from this data. Furthermore, lab-based measurements are affected by the polychromatic X-ray beam, which results in beam hardening effects. New types of X-ray detectors w...

  7. Computational analysis of bacterial RNA-Seq data.

    McClure, Ryan; Balasubramanian, Divya; Sun, Yan; Bobrovskyy, Maksym; Sumby, Paul; Genco, Caroline A; Vanderpool, Carin K; Tjaden, Brian

    2013-08-01

    Recent advances in high-throughput RNA sequencing (RNA-seq) have enabled tremendous leaps forward in our understanding of bacterial transcriptomes. However, computational methods for analysis of bacterial transcriptome data have not kept pace with the large and growing data sets generated by RNA-seq technology. Here, we present new algorithms, specific to bacterial gene structures and transcriptomes, for analysis of RNA-seq data. The algorithms are implemented in an open source software system called Rockhopper that supports various stages of bacterial RNA-seq data analysis, including aligning sequencing reads to a genome, constructing transcriptome maps, quantifying transcript abundance, testing for differential gene expression, determining operon structures and visualizing results. We demonstrate the performance of Rockhopper using 2.1 billion sequenced reads from 75 RNA-seq experiments conducted with Escherichia coli, Neisseria gonorrhoeae, Salmonella enterica, Streptococcus pyogenes and Xenorhabdus nematophila. We find that the transcriptome maps generated by our algorithms are highly accurate when compared with focused experimental data from E. coli and N. gonorrhoeae, and we validate our system's ability to identify novel small RNAs, operons and transcription start sites. Our results suggest that Rockhopper can be used for efficient and accurate analysis of bacterial RNA-seq data, and that it can aid with elucidation of bacterial transcriptomes.

  8. The future of computer-aided sperm analysis

    Sharon T Mortimer

    2015-01-01

    Full Text Available Computer-aided sperm analysis (CASA technology was developed in the late 1980s for analyzing sperm movement characteristics or kinematics and has been highly successful in enabling this field of research. CASA has also been used with great success for measuring semen characteristics such as sperm concentration and proportions of progressive motility in many animal species, including wide application in domesticated animal production laboratories and reproductive toxicology. However, attempts to use CASA for human clinical semen analysis have largely met with poor success due to the inherent difficulties presented by many human semen samples caused by sperm clumping and heavy background debris that, until now, have precluded accurate digital image analysis. The authors review the improved capabilities of two modern CASA platforms (Hamilton Thorne CASA-II and Microptic SCA6 and consider their current and future applications with particular reference to directing our focus towards using this technology to assess functional rather than simple descriptive characteristics of spermatozoa. Specific requirements for validating CASA technology as a semi-automated system for human semen analysis are also provided, with particular reference to the accuracy and uncertainty of measurement expected of a robust medical laboratory test for implementation in clinical laboratories operating according to modern accreditation standards.

  9. Optical compensation device for chest film radiography

    Gould, Robert G.; Hasegawa, Bruce H.; DeForest, Sherman E.; Schmidt, Gregory W.; Hier, Richard G.

    1990-07-01

    Although chest radiography is the most commonly performed radiographic examination and one of the most valuable and cost-effective studies in medicine it suffers from relatively high error rates in both missing pathology and false positive interpretations. Detectability of lung nodules and other structures in underpenetrated regions of the chest film can be improved by both exposure and optical compensation but current compensation systems require major capital cost or a significant change in normal clinical practice. A new optical compensation system called the " Intelligent X-Ray Illuminator" (IXI) automatically and virtually instantaneously generates a patient-specific optical unsharp mask that is projected directly on a radiograph. When a radiograph is placed on the IXI which looks much like a conventional viewbox it acquires a low-resolution electronic image of this film from which the film transmission is derived. The transmission information is inverted and blurred in an image processor to form an unsharp mask which is fed into a spatial light modulator (SLM) placed between a light source and the radiograph. The SLM tailors the viewbox luminance by decreasing illumination to underexposed (i. e. transmissive) areas of the radiograph presenting the observer with an optically unsharp-masked image. The IXI uses the original radiograph and will allow it to be viewed on demand with conventional (uniform illumination. Potentially the IXI could introduce the known beneficial aspects of optical unsharp masking into radiology at low capital

  10. Towards Proton Therapy and Radiography at FAIR

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

    2015-04-01

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

  11. Needle image plates compared to conventional CR in chest radiography: Is dose reduction possible?

    Berger-Kulemann, Vanessa, E-mail: vanessa.berger-kulemann@meduniwien.ac.at [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Pötter-Lang, Sarah; Gruber, Michael [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Berger, Rudolf [Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Vonbank, Karin [Department of Internal Medicine II, Division of Pneumology, Medical University of Vienna Waehringer Guertel 18-20, 1090 Vienna (Austria); Weber, Michael [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Rabitsch, Werner [Department of Internal Medicine I, Bone Marrow Transplantation, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Uffmann, Martin [Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Department of Radiology, KH Neunkirchen, Peischinger Straße 19, 2620 Neunkirchen (Austria)

    2012-12-15

    Purpose: To compare image quality of standard-dose computed radiography and dose reduced needle-technology CR for supine CXR in a clinical setting. Materials and methods: We prospectively evaluated 128 radiographs of 32 immunocompromised patients. For each patient four clinical CXR were performed within one week, two with powder image plates (PIP; Fuji ST-V) and two with needle image plates (NIP; Agfa DXS) at standard and half dose, respectively. One experienced radiologist and two residents blinded to dose level and kind of imaging system rated different anatomical structures, image noise, tubes/lines and abnormalities on a image quality scale from 1 to 10 (1 = poor, 10 = excellent). The rating scores were tested for statistical differences using analysis of variance with repeated measures. Results: A statistical difference (p < 0.05) was found for the two systems as well as for the two dose levels. Overall rating scores were 6.5 for PIP with full dose, 6.2 for PIP with half dose, 7.6 for NIP with full dose and 7.4 for NIP with half dose. There was a significant difference in favour of the NIP system at the same dose level. Also the NIP images obtained at half dose were ranked significantly better compared to the PIP images at standard dose. The differences in ranking of anatomical structures and abnormalities were more pronounced in low absorption areas (pulmonary vessels, parenchyma) than in high absorption areas (mediastinum, spine). Conclusion: For supine chest radiograms the NIP technology allows for a dose reduction of 50% while providing higher image quality.

  12. Gender Differences in Computer-Related Attitudes and Behavior: A Meta-Analysis.

    Whitley, Bernard E., Jr.

    1997-01-01

    A meta-analysis of studies of gender differences in computer attitudes and behavior found that males exhibited greater sex-role stereotyping of computers, higher computer self-efficacy, and more positive attitudes toward computers than females. Most differences in attitudes and behavior were small, with the largest found in high school students.…

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

    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.

  14. Computational Analysis on Stent Geometries in Carotid Artery: A Review

    Paisal, Muhammad Sufyan Amir; Taib, Ishkrizat; Ismail, Al Emran

    2017-01-01

    This paper reviews the work done by previous researchers in order to gather the information for the current study which about the computational analysis on stent geometry in carotid artery. The implantation of stent in carotid artery has become popular treatment for arterial diseases of hypertension such as stenosis, thrombosis, atherosclerosis and embolization, in reducing the rate of mortality and morbidity. For the stenting of an artery, the previous researchers did many type of mathematical models in which, the physiological variables of artery is analogized to electrical variables. Thus, the computational fluid dynamics (CFD) of artery could be done, which this method is also did by previous researchers. It lead to the current study in finding the hemodynamic characteristics due to artery stenting such as wall shear stress (WSS) and wall shear stress gradient (WSSG). Another objective of this study is to evaluate the nowadays stent configuration for full optimization in reducing the arterial side effect such as restenosis rate after a few weeks of stenting. The evaluation of stent is based on the decrease of strut-strut intersection, decrease of strut width and increase of the strut-strut spacing. The existing configuration of stents are actually good enough in widening the narrowed arterial wall but the disease such as thrombosis still occurs in early and late stage after the stent implantation. Thus, the outcome of this study is the prediction for the reduction of restenosis rate and the WSS distribution is predicted to be able in classifying which stent configuration is the best.

  15. Novel computational approaches for the analysis of cosmic magnetic fields

    Saveliev, Andrey [Universitaet Hamburg, Hamburg (Germany); Keldysh Institut, Moskau (Russian Federation)

    2016-07-01

    In order to give a consistent picture of cosmic, i.e. galactic and extragalactic, magnetic fields, different approaches are possible and often even necessary. Here we present three of them: First, a semianalytic analysis of the time evolution of primordial magnetic fields from which their properties and, subsequently, the nature of present-day intergalactic magnetic fields may be deduced. Second, the use of high-performance computing infrastructure by developing powerful algorithms for (magneto-)hydrodynamic simulations and applying them to astrophysical problems. We are currently developing a code which applies kinetic schemes in massive parallel computing on high performance multiprocessor systems in a new way to calculate both hydro- and electrodynamic quantities. Finally, as a third approach, astroparticle physics might be used as magnetic fields leave imprints of their properties on charged particles transversing them. Here we focus on electromagnetic cascades by developing a software based on CRPropa which simulates the propagation of particles from such cascades through the intergalactic medium in three dimensions. This may in particular be used to obtain information about the helicity of extragalactic magnetic fields.

  16. NALDA (Naval Aviation Logistics Data Analysis) CAI (computer aided instruction)

    Handler, B.H. (Oak Ridge K-25 Site, TN (USA)); France, P.A.; Frey, S.C.; Gaubas, N.F.; Hyland, K.J.; Lindsey, A.M.; Manley, D.O. (Oak Ridge Associated Universities, Inc., TN (USA)); Hunnum, W.H. (North Carolina Univ., Chapel Hill, NC (USA)); Smith, D.L. (Memphis State Univ., TN (USA))

    1990-07-01

    Data Systems Engineering Organization (DSEO) personnel developed a prototype computer aided instruction CAI system for the Naval Aviation Logistics Data Analysis (NALDA) system. The objective of this project was to provide a CAI prototype that could be used as an enhancement to existing NALDA training. The CAI prototype project was performed in phases. The task undertaken in Phase I was to analyze the problem and the alternative solutions and to develop a set of recommendations on how best to proceed. The findings from Phase I are documented in Recommended CAI Approach for the NALDA System (Duncan et al., 1987). In Phase II, a structured design and specifications were developed, and a prototype CAI system was created. A report, NALDA CAI Prototype: Phase II Final Report, was written to record the findings and results of Phase II. NALDA CAI: Recommendations for an Advanced Instructional Model, is comprised of related papers encompassing research on computer aided instruction CAI, newly developing training technologies, instructional systems development, and an Advanced Instructional Model. These topics were selected because of their relevancy to the CAI needs of NALDA. These papers provide general background information on various aspects of CAI and give a broad overview of new technologies and their impact on the future design and development of training programs. The paper within have been index separately elsewhere.

  17. Computational Approach to Dendritic Spine Taxonomy and Shape Transition Analysis

    Bokota, Grzegorz; Magnowska, Marta; Kuśmierczyk, Tomasz; Łukasik, Michał; Roszkowska, Matylda; Plewczynski, Dariusz

    2016-01-01

    The common approach in morphological analysis of dendritic spines of mammalian neuronal cells is to categorize spines into subpopulations based on whether they are stubby, mushroom, thin, or filopodia shaped. The corresponding cellular models of synaptic plasticity, long-term potentiation, and long-term depression associate the synaptic strength with either spine enlargement or spine shrinkage. Although a variety of automatic spine segmentation and feature extraction methods were developed recently, no approaches allowing for an automatic and unbiased distinction between dendritic spine subpopulations and detailed computational models of spine behavior exist. We propose an automatic and statistically based method for the unsupervised construction of spine shape taxonomy based on arbitrary features. The taxonomy is then utilized in the newly introduced computational model of behavior, which relies on transitions between shapes. Models of different populations are compared using supplied bootstrap-based statistical tests. We compared two populations of spines at two time points. The first population was stimulated with long-term potentiation, and the other in the resting state was used as a control. The comparison of shape transition characteristics allowed us to identify the differences between population behaviors. Although some extreme changes were observed in the stimulated population, statistically significant differences were found only when whole models were compared. The source code of our software is freely available for non-commercial use1. Contact: d.plewczynski@cent.uw.edu.pl. PMID:28066226

  18. Application of Computer Integration Technology for Fire Safety Analysis

    SHI Jianyong; LI Yinqing; CHEN Huchuan

    2008-01-01

    With the development of information technology, the fire safety assessment of whole structure or region based on the computer simulation has become a hot topic. However, traditionally, the concemed studies are performed separately for different objectives and difficult to perform an overall evaluation. A new multi-dimensional integration model and methodology for fire safety assessment were presented and two newly developed integrated systems were introduced to demonstrate the function of integration simulation technology in this paper. The first one is the analysis on the fire-resistant behaviors of whole structure under real fire loads. The second one is the study on fire evaluation and emergency rescue of campus based on geography information technology (GIS). Some practical examples are presented to illuminate the advan-tages of computer integration technology on fire safety assessment and emphasize some problems in the simulation. The results show that the multi-dimensional integration model offers a new way and platform for the integrating fire safety assessment of whole structure or region, and the integrated software developed is the useful engineering tools for cost-saving and safe design.

  19. COMPUTING

    M. Kasemann

    Overview In autumn the main focus was to process and handle CRAFT data and to perform the Summer08 MC production. The operational aspects were well covered by regular Computing Shifts, experts on duty and Computing Run Coordination. At the Computing Resource Board (CRB) in October a model to account for service work at Tier 2s was approved. The computing resources for 2009 were reviewed for presentation at the C-RRB. The quarterly resource monitoring is continuing. Facilities/Infrastructure operations Operations during CRAFT data taking ran fine. This proved to be a very valuable experience for T0 workflows and operations. The transfers of custodial data to most T1s went smoothly. A first round of reprocessing started at the Tier-1 centers end of November; it will take about two weeks. The Computing Shifts procedure was tested full scale during this period and proved to be very efficient: 30 Computing Shifts Persons (CSP) and 10 Computing Resources Coordinators (CRC). The shift program for the shut down w...

  20. Multiresolution analysis over simple graphs for brain computer interfaces

    Asensio-Cubero, J.; Gan, J. Q.; Palaniappan, R.

    2013-08-01

    Objective. Multiresolution analysis (MRA) offers a useful framework for signal analysis in the temporal and spectral domains, although commonly employed MRA methods may not be the best approach for brain computer interface (BCI) applications. This study aims to develop a new MRA system for extracting tempo-spatial-spectral features for BCI applications based on wavelet lifting over graphs. Approach. This paper proposes a new graph-based transform for wavelet lifting and a tailored simple graph representation for electroencephalography (EEG) data, which results in an MRA system where temporal, spectral and spatial characteristics are used to extract motor imagery features from EEG data. The transformed data is processed within a simple experimental framework to test the classification performance of the new method. Main Results. The proposed method can significantly improve the classification results obtained by various wavelet families using the same methodology. Preliminary results using common spatial patterns as feature extraction method show that we can achieve comparable classification accuracy to more sophisticated methodologies. From the analysis of the results we can obtain insights into the pattern development in the EEG data, which provide useful information for feature basis selection and thus for improving classification performance. Significance. Applying wavelet lifting over graphs is a new approach for handling BCI data. The inherent flexibility of the lifting scheme could lead to new approaches based on the hereby proposed method for further classification performance improvement.

  1. Detection of Organophosphorus Pesticides with Colorimetry and Computer Image Analysis.

    Li, Yanjie; Hou, Changjun; Lei, Jincan; Deng, Bo; Huang, Jing; Yang, Mei

    2016-01-01

    Organophosphorus pesticides (OPs) represent a very important class of pesticides that are widely used in agriculture because of their relatively high-performance and moderate environmental persistence, hence the sensitive and specific detection of OPs is highly significant. Based on the inhibitory effect of acetylcholinesterase (AChE) induced by inhibitors, including OPs and carbamates, a colorimetric analysis was used for detection of OPs with computer image analysis of color density in CMYK (cyan, magenta, yellow and black) color space and non-linear modeling. The results showed that there was a gradually weakened trend of yellow intensity with the increase of the concentration of dichlorvos. The quantitative analysis of dichlorvos was achieved by Artificial Neural Network (ANN) modeling, and the results showed that the established model had a good predictive ability between training sets and predictive sets. Real cabbage samples containing dichlorvos were detected by colorimetry and gas chromatography (GC), respectively. The results showed that there was no significant difference between colorimetry and GC (P > 0.05). The experiments of accuracy, precision and repeatability revealed good performance for detection of OPs. AChE can also be inhibited by carbamates, and therefore this method has potential applications in real samples for OPs and carbamates because of high selectivity and sensitivity.

  2. Importance sampling. I. Computing multimodel p values in linkage analysis

    Kong, A.; Frigge, M.; Irwin, M.; Cox, N. (Univ. of Chicago, IL (United States))

    1992-12-01

    In linkage analysis, when the lod score is maximized over multiple genetic models, standard asymptotic approximation of the significance level does not apply. Monte Carlo methods can be used to estimate the p value, but procedures currently used are extremely inefficient. The authors propose a Monte Carlo procedure based on the concept of importance sampling, which can be thousands of times more efficient than current procedures. With a reasonable amount of computing time, extremely accurate estimates of the p values can be obtained. Both theoretical results and an example of maturity-onset diabetes of the young (MODY) are presented to illustrate the efficiency performance of their method. Relations between single-model and multimodel p values are explored. The new procedure is also used to investigate the performance of asymptotic approximations in a single model situation. 22 refs., 6 figs., 1 tab.

  3. Meta-Analysis and Computer-Mediated Communication.

    Taylor, Alan M

    2016-04-01

    Because of the use of human participants and differing contextual variables, research in second language acquisition often produces conflicting results, leaving practitioners confused and unsure of the effectiveness of specific treatments. This article provides insight into a recent seminal meta-analysis on the effectiveness of computer-mediated communication, providing further statistical evidence of the importance of its results. The significance of the study is examined by looking at the p values included in the references, to demonstrate how results can easily be misconstrued by practitioners and researchers. Lin's conclusion regarding the research setting of the study reports is also evaluated. In doing so, other possible explanations of what may be influencing the results can be proposed.

  4. Automation of Large-scale Computer Cluster Monitoring Information Analysis

    Magradze, Erekle; Nadal, Jordi; Quadt, Arnulf; Kawamura, Gen; Musheghyan, Haykuhi

    2015-12-01

    High-throughput computing platforms consist of a complex infrastructure and provide a number of services apt to failures. To mitigate the impact of failures on the quality of the provided services, a constant monitoring and in time reaction is required, which is impossible without automation of the system administration processes. This paper introduces a way of automation of the process of monitoring information analysis to provide the long and short term predictions of the service response time (SRT) for a mass storage and batch systems and to identify the status of a service at a given time. The approach for the SRT predictions is based on Adaptive Neuro Fuzzy Inference System (ANFIS). An evaluation of the approaches is performed on real monitoring data from the WLCG Tier 2 center GoeGrid. Ten fold cross validation results demonstrate high efficiency of both approaches in comparison to known methods.

  5. Computational analysis of azine-N-oxides as energetic materials

    Ritchie, J.P.

    1994-05-01

    A BKW equation of state in a 1-dimensional hydrodynamic simulation of the cylinder test can be used to estimate the performance of explosives. Using this approach, the novel explosive 1,4-diamino-2,3,5,6-tetrazine-2,5-dioxide (TZX) was analyzed. Despite a high detonation velocity and a predicted CJ pressure comparable to that of RDX, TZX performs relatively poorly in the cylinder test. Theoretical and computational analysis shows this to be the result of a low heat of detonation. A conceptual strategy is proposed to remedy this problem. In order to predict the required heats of formation, new ab initio group equivalents were developed. Crystal structure calculations are also described that show hydrogen-bonding is important in determining the density of TZX and related compounds.

  6. Web Pages Content Analysis Using Browser-Based Volunteer Computing

    Wojciech Turek

    2013-01-01

    Full Text Available Existing solutions to the problem of finding valuable information on the Websuffers from several limitations like simplified query languages, out-of-date in-formation or arbitrary results sorting. In this paper a different approach to thisproblem is described. It is based on the idea of distributed processing of Webpages content. To provide sufficient performance, the idea of browser-basedvolunteer computing is utilized, which requires the implementation of text pro-cessing algorithms in JavaScript. In this paper the architecture of Web pagescontent analysis system is presented, details concerning the implementation ofthe system and the text processing algorithms are described and test resultsare provided.

  7. Data analysis using the Gnu R system for statistical computation

    Simone, James; /Fermilab

    2011-07-01

    R is a language system for statistical computation. It is widely used in statistics, bioinformatics, machine learning, data mining, quantitative finance, and the analysis of clinical drug trials. Among the advantages of R are: it has become the standard language for developing statistical techniques, it is being actively developed by a large and growing global user community, it is open source software, it is highly portable (Linux, OS-X and Windows), it has a built-in documentation system, it produces high quality graphics and it is easily extensible with over four thousand extension library packages available covering statistics and applications. This report gives a very brief introduction to R with some examples using lattice QCD simulation results. It then discusses the development of R packages designed for chi-square minimization fits for lattice n-pt correlation functions.

  8. Computational Fluid Dynamics Analysis of an Evaporative Cooling System

    Kapilan N.

    2016-11-01

    Full Text Available The use of chlorofluorocarbon based refrigerants in the air-conditioning system increases the global warming and causes the climate change. The climate change is expected to present a number of challenges for the built environment and an evaporative cooling system is one of the simplest and environmentally friendly cooling system. The evaporative cooling system is most widely used in summer and in rural and urban areas of India for human comfort. In evaporative cooling system, the addition of water into air reduces the temperature of the air as the energy needed to evaporate the water is taken from the air. Computational fluid dynamics is a numerical analysis and was used to analyse the evaporative cooling system. The CFD results are matches with the experimental results.

  9. Time Series Analysis, Modeling and Applications A Computational Intelligence Perspective

    Chen, Shyi-Ming

    2013-01-01

    Temporal and spatiotemporal data form an inherent fabric of the society as we are faced with streams of data coming from numerous sensors, data feeds, recordings associated with numerous areas of application embracing physical and human-generated phenomena (environmental data, financial markets, Internet activities, etc.). A quest for a thorough analysis, interpretation, modeling and prediction of time series comes with an ongoing challenge for developing models that are both accurate and user-friendly (interpretable). The volume is aimed to exploit the conceptual and algorithmic framework of Computational Intelligence (CI) to form a cohesive and comprehensive environment for building models of time series. The contributions covered in the volume are fully reflective of the wealth of the CI technologies by bringing together ideas, algorithms, and numeric studies, which convincingly demonstrate their relevance, maturity and visible usefulness. It reflects upon the truly remarkable diversity of methodological a...

  10. Location of mental foramen using digital panoramic radiography

    Ajmal Mohamed

    2016-01-01

    Full Text Available Objective: Comparative evaluation of the location of mental foramen in different age groups. Determine the variation in position of mental foramen with gender using digital panoramic radiography. Materials and Methods: Digital panoramic radiographs of 250 patients were reviewed. The study population was divided into five age groups with 50 patients each. Radiographic position of mental foramen was evaluated in each radiograph based on three parameters. Measurements were taken in each radiograph using Planmeca Dimaxis pro version 4.4.0 (Helsinki, Finland. The collected data were subjected to statistical analysis using paired Student's t-test. Results: The mean distance of position of mental foramen showed a significant variation within the five age groups. In the first group, female patients showed an increase in mean distance of mental foramen position in relation to three parameters. From the second to fifth groups, male patient showed an increase in the mean distance of mental foramen position. The first and fifth group showed a reduced mean distance of mental foramen position when compared to other age groups. Conclusion: This study concluded that the position of mental foramen varies with age. There was a gender-related variation in position of mental foramen within the population too.

  11. Location of mental foramen using digital panoramic Radiography

    Mohamed, Ajmal; Nataraj, Kannan; Mathew, Vinod B.; Varma, Beena; Mohamed, Shamil; Valappila, Nidhin J.; Meena, Aravind S.

    2016-01-01

    Objective: Comparative evaluation of the location of mental foramen in different age groups. Determine the variation in position of mental foramen with gender using digital panoramic radiography. Materials and Methods: Digital panoramic radiographs of 250 patients were reviewed. The study population was divided into five age groups with 50 patients each. Radiographic position of mental foramen was evaluated in each radiograph based on three parameters. Measurements were taken in each radiograph using Planmeca Dimaxis pro version 4.4.0 (Helsinki, Finland). The collected data were subjected to statistical analysis using paired Student's t-test. Results: The mean distance of position of mental foramen showed a significant variation within the five age groups. In the first group, female patients showed an increase in mean distance of mental foramen position in relation to three parameters. From the second to fifth groups, male patient showed an increase in the mean distance of mental foramen position. The first and fifth group showed a reduced mean distance of mental foramen position when compared to other age groups. Conclusion: This study concluded that the position of mental foramen varies with age. There was a gender-related variation in position of mental foramen within the population too. PMID:27555723

  12. Triclosan Computational Conformational Chemistry Analysis for Antimicrobial Properties in Polymers.

    Petersen, Richard C

    2015-03-01

    Triclosan is a diphenyl ether antimicrobial that has been analyzed by computational conformational chemistry for an understanding of Mechanomolecular Theory. Subsequent energy profile analysis combined with easily seen three-dimensional chemistry structure models for the nonpolar molecule Triclosan show how single bond rotations can alternate rapidly at a polar and nonpolar interface. Bond rotations for the center ether oxygen atom of the two aromatic rings then expose or hide nonbonding lone-pair electrons for the oxygen atom depending on the polar nature of the immediate local molecular environment. Rapid bond movements can subsequently produce fluctuations as vibration energy. Consequently, related mechanical molecular movements calculated as energy relationships by forces acting through different bond positions can help improve on current Mechanomolecular Theory. A previous controversy reported as a discrepancy in literature contends for a possible bacterial resistance from Triclosan antimicrobial. However, findings in clinical settings have not reported a single case for Triclosan bacterial resistance in over 40 years that has been documented carefully in government reports. As a result, Triclosan is recommended whenever there is a health benefit consistent with a number of approvals for use of Triclosan in healthcare devices. Since Triclosan is the most researched antimicrobial ever, literature meta analysis with computational chemistry can best describe new molecular conditions that were previously impossible by conventional chemistry methods. Triclosan vibrational energy can now explain the molecular disruption of bacterial membranes. Further, Triclosan mechanomolecular movements help illustrate use in polymer matrix composites as an antimicrobial with two new additive properties as a toughening agent to improve matrix fracture toughness from microcracking and a hydrophobic wetting agent to help incorporate strengthening fibers. Interrelated

  13. Computer-assisted sperm analysis (CASA): capabilities and potential developments.

    Amann, Rupert P; Waberski, Dagmar

    2014-01-01

    Computer-assisted sperm analysis (CASA) systems have evolved over approximately 40 years, through advances in devices to capture the image from a microscope, huge increases in computational power concurrent with amazing reduction in size of computers, new computer languages, and updated/expanded software algorithms. Remarkably, basic concepts for identifying sperm and their motion patterns are little changed. Older and slower systems remain in use. Most major spermatology laboratories and semen processing facilities have a CASA system, but the extent of reliance thereon ranges widely. This review describes capabilities and limitations of present CASA technology used with boar, bull, and stallion sperm, followed by possible future developments. Each marketed system is different. Modern CASA systems can automatically view multiple fields in a shallow specimen chamber to capture strobe-like images of 500 to >2000 sperm, at 50 or 60 frames per second, in clear or complex extenders, and in CASA cannot accurately predict 'fertility' that will be obtained with a semen sample or subject. However, when carefully validated, current CASA systems provide information important for quality assurance of semen planned for marketing, and for the understanding of the diversity of sperm responses to changes in the microenvironment in research. The four take-home messages from this review are: (1) animal species, extender or medium, specimen chamber, intensity of illumination, imaging hardware and software, instrument settings, technician, etc., all affect accuracy and precision of output values; (2) semen production facilities probably do not need a substantially different CASA system whereas biology laboratories would benefit from systems capable of imaging and tracking sperm in deep chambers for a flexible period of time; (3) software should enable grouping of individual sperm based on one or more attributes so outputs reflect subpopulations or clusters of similar sperm with unique

  14. Summary of research in applied mathematics, numerical analysis, and computer sciences

    1986-01-01

    The major categories of current ICASE research programs addressed include: numerical methods, with particular emphasis on the development and analysis of basic numerical algorithms; control and parameter identification problems, with emphasis on effective numerical methods; computational problems in engineering and physical sciences, particularly fluid dynamics, acoustics, and structural analysis; and computer systems and software, especially vector and parallel computers.

  15. A procedure for the evaluation of 2D radiographic texture analysis to assess 3D bone micro-architecture; Evaluation de l'analyse de la texture de radiographies 2D pour evaluer les micro architecture 3D d'os

    Apostol, L.; Peyrin, F.; Yot, S.; Basset, O.; Odet, Ch. [CREATIS - Centre National de la Recherche Scientifique (UMR CNRS 5515), 69 - Villeurbanne (France); Apostal, L.; Boller, E. [European Synchrotron Radiation Facility (ESRF), 38 - Grenoble (France); Tabary, J.; Dinten, J.M. [CEA Grenoble, Lab. d' Electronique et de Technologie de l' Informatique (LETI), 38 (France); Boudousq, V.; Kotzki, P.O. [Faculte de Medecine, Lab. de Biophysique Medicale, 30 - Nimes (France)

    2004-07-01

    Although the diagnosis of osteoporosis is mainly based on Dual X-ray Absorptiometry, it has been shown that trabecular bone micro-architecture is also an important factor in regards of fracture risk, which can be efficiently assessed in vitro using three-dimensional x-ray microtomography ({mu}CT). In vivo, techniques based on high-resolution x-ray radiography associated to texture analysis have been proposed to investigate bone micro-architecture, but their relevance for giving pertinent 3D information is unclear. The purpose of this work was to develop a method for evaluating the relationships between 3D micro-architecture and 2D texture parameters, and optimizing the conditions for radiographic imaging. Bone sample images taken from cortical to cortical were acquired using 3D-synchrotron x-ray {mu}CT at the ESRF. The 3D digital images were further used for two purposes: 1) quantification of three-dimensional bone micro-architecture, 2) simulation of realistic x-ray radiographs under different acquisition conditions. Texture analysis was then applied to these 2D radiographs using a large variety of methods (co-occurrence, spectrum, fractal...). First results of the statistical analysis between 2D and 3D parameters allowed identifying the most relevant 2D texture parameters. (authors)

  16. 牙颌面锥形束CT与曲面体层X线检查对颌骨牙骨质瘤样病变诊断价值的比较研究%Comparative Studies of Diagnostic Evaluation of the Maxillary and Mandibular Cementoma Using Cone Beam Computer ized Tomography Compared with Panoramic Radiography

    龙卫平; 谭跃展; 翦新春; 钟锐

    2012-01-01

    Objective: To assess the osseous lesions of the maxillary and mandibular cementoma by dental cone beam computerized tomography (CBCT) and to compare it with panoramic radiography. Methods: Three patients with the maxillary and mandibular cementoma had undergone panoramic radiographic and dental come beam computerized tomographic examinations. The results were compared and the accuracy with CBCT and panoramic radiography was assessed. Results; Panoramic radiography showed sizes and scopes of the lesions in the maxilla and mandible. Cone beam computerized tomography reproduced multiple images including axial. coronal and sagittal planes of the lesions. Cone beam computerized tomography also provided a complete radiographic investigation of the cementoma in the maxilla and mandible. Conclusion: Cone beam computerized tomography is one of the best choices of imaging diagnosis of cementoma in the maxilla and mandible.%目的:比较牙颌面专用CBCT与曲面体层对颌骨牙骨质瘤的诊断价值.方法:对3例发生于上下颌骨中的牙骨质瘤患者,分别选用曲面体层和CBCT检查,并将检查结果进行比较分析,判断相互之间的一致性和差异性.结果:3例上下颌骨内牙骨质瘤病变,在曲面体层上均有显示,但CBCT检查可以在矢状位、冠状位和横断面上以多个层面准确地反映病变的位置及骨质破坏的情况.结论:CBCT在对上下颌骨牙骨质瘤的诊断较曲面体层更为有价值.

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

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

    2013-04-01

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

  18. Syndesmotic Malreduction after Ankle ORIF; Is Radiography Sufficient?

    Alireza Manafi Rasi

    2013-12-01

    Full Text Available Background: Ankle fractures, especially those resulting from external rotation mechanisms are associated with injury to the distal tibiofibular syndesmosis. Some authors have recommended performing CT scanning after open ankle surgery to evaluate the reduction of syndesmosis. In this current study, we aimed to investigate the sensitivity of plain radiography in diagnosing syndesmosis malreduction after open reduction and internal fixation (ORIF in patients with ankle fractures.   Methods: Thirty patients with ankle fractures participated in this prospective study. ORIFs were performed with respect to all of the technical guidelines shown in orthopedic literature for exact syndesmosis reduction, such as fibular length and proper settings. In the operating room, plain radiography was performed in anteroposterior, mortise and lateral views to assess whether syndesmosis was malreduced. If malreduction was detected, the patient was revised. As the gold standard, patients underwent postoperative bilateral CT scanning to investigate the syndesmosis reduction which was then compared to the healthy side. Finally, the sensitivity of plain radiography in the diagnosis of syndesmosis malreduction was determined by comparing this method to CT scanning. Results: In both of the methods we did not find any patient with syndesmosis malreduction. Hence, the sensitivity of plain radiography was determined 100%. Conclusion: Based on our findings, there is no need to perform CT scanning to evaluate syndesmosis reduction after ankle ORIF in patients with ankle fractures. Plain radiography is sufficient and has satisfactory sensitivity in these patients.

  19. Syndesmotic Malreduction after Ankle ORIF; Is Radiography Sufficient?

    Alireza Manafi Rasi

    2013-12-01

    Full Text Available   Background: Ankle fractures, especially those resulting from external rotation mechanisms are associated with injury to the distal tibiofibular syndesmosis. Some authors have recommended performing CT scanning after open ankle surgery to evaluate the reduction of syndesmosis. In this current study, we aimed to investigate the sensitivity of plain radiography in diagnosing syndesmosis malreduction after open reduction and internal fixation (ORIF in patients with ankle fractures.   Methods: Thirty patients with ankle fractures participated in this prospective study. ORIFs were performed with respect to all of the technical guidelines shown in orthopedic literature for exact syndesmosis reduction, such as fibular length and proper settings. In the operating room, plain radiography was performed in anteroposterior, mortise and lateral views to assess whether syndesmosis was malreduced. If malreduction was detected, the patient was revised. As the gold standard, patients underwent postoperative bilateral CT scanning to investigate the syndesmosis reduction which was then compared to the healthy side. Finally, the sensitivity of plain radiography in the diagnosis of syndesmosis malreduction was determined by comparing this method to CT scanning. Results: In both of the methods we did not find any patient with syndesmosis malreduction. Hence, the sensitivity of plain radiography was determined 100%. Conclusion: Based on our findings, there is no need to perform CT scanning to evaluate syndesmosis reduction after ankle ORIF in patients with ankle fractures. Plain radiography is sufficient and has satisfactory sensitivity in these patients.

  20. Accuracy of Digital Bitewing Radiography versus Different Views of Digital Panoramic Radiography for Detection of Proximal Caries

    Abdinian, Mehrdad; Razavi, Sayed Mohammad; Samety, Amir Abbas; Faghihian, Elham

    2015-01-01

    Objectives: Dental caries are common and have a high incidence among populations. Radiographs are essential for detecting proximal caries. The best technique should be recognized for accurate detection of caries. The aim of this study was to compare the accuracy of detection of proximal caries using intraoral bitewing, extraoral bitewing, improved interproximal panoramic, improved orthogonality panoramic and conventional panoramic radiographs. Materials and Methods: In this descriptive cross sectional study, 100 extracted human teeth with and without proximal caries were used. Intra and extraoral radiographs were taken. Images were evaluated and scored by two observers. Scores were compared with the histological gold standard. The diagnostic accuracy of radiographs was assessed by means of receiver operating characteristic (ROC) curve analysis (P<0.05). Results: Microscopic evaluation of proximal surfaces revealed that 54.8% of the surfaces were sound and 45.2% were carious (with different depths). The differences in the area under the ROC curve (Az value) among the five techniques were not statistically significant. Conclusion: Improved interproximal panoramic and extraoral bitewing radiographs were superior to conventional panoramic radiography for detection of proximal caries ex vivo and should be considered for patients with contraindications for intraoral radiographs. PMID:26622284