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Sample records for computed radiography analysis

  1. Analysis of the painting 'Gioventu' (Eliseu Visconti) using EDXRF and computed radiography

    Calza, Cristiane [Nuclear Instrumentation Laboratory-COPPE/UFRJ, Rio de Janeiro (Brazil)], E-mail: ccalza@lin.ufrj.br; Oliveira, Davi F.; Souza Rocha, Henrique de [Nuclear Instrumentation Laboratory-COPPE/UFRJ, Rio de Janeiro (Brazil); Pedreira, Andrea [National Museum of Fine Arts, Rio de Janeiro (Brazil); Tadeu Lopes, Ricardo [Nuclear Instrumentation Laboratory-COPPE/UFRJ, Rio de Janeiro (Brazil)

    2010-04-15

    In this work, the painting 'Gioventu' (Eliseu Visconti, 1898) was analyzed by means of energy dispersive X-ray fluorescence and computed radiography. A portable EDXRF system was employed to identify the pigments used by the artist: yellow, red and brown ocher; umber; vermilion; cobalt blue; lead white and viridian (or chromium oxide). The CR analysis revealed that the painting was in a good state of conservation and also a previous composition hidden under the painting.

  2. Pediatric musculoskeletal computed radiography

    Background. In conventional radiography, a film-screen system serves as the X-ray detector and the film also functions as an archival and display medium. Unlike film-screen radiography, these functions are uncoupled in computed radiography (CR). CR uses conventional radiographic equipment to expose an image on a storage phosphor plate instead of a film-screen combination. Objective. To review the basic concepts of CR and to provide a background for discussion of specific musculoskeletal applications of CR in children. Materials and methods. Various aspects of musculoskeletal CR in children are presented based on our 4 years' experience and a review of the literature. Results. A greater amount of scatter capture occurs with storage phosphor CR than with a film-screen system in the 70- to 120-kVp range. This is attributed to a lower K-absorption edge of barium in the barium fluorohalide (BaFBr) compound used in the imaging plate. A significant reduction of scatter to primary radiation, improvement in bony trabecular sharpness, and improvement in line pair resolution can be achieved in pediatric musculoskeletal imaging using an air gap without an increase in the skin entrance dose as compared to the non-grid table top technique. With CR, in addition to proper radiographic exposure technique, one needs to preprogram and select the optimal processing technique for each anatomic region, projection and age group of the child. Conclusion. The main advantages of CR in pediatric musculoskeletal imaging consist of a reduction in radiation dose for many applications, improved contrast resolution, near elimination of repeat radiographs related to exposure errors, and digital processing capabilities for image enhancement, storage, retrieval, display and transmission. The current limitations of CR include the moderately high start-up cost, the long learning curve to produce optimal films, and the reduced spatial resolution. (orig.). With 8 figs., 2 tabs

  3. Computational radiology in skeletal radiography

    Peloschek, Ph.; Nemec, S. [Computational Image Analysis and Radiology Lab (CIR), Department of Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Widhalm, P. [Computational Image Analysis and Radiology Lab (CIR), Department of Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Pattern Recognition and Image Processing Group, Department of Computer Aided Automation, Vienna University of Technology, Wiedner Hauptstrasse 8-10/020, A-1040 Vienna (Austria); Donner, R. [Computational Image Analysis and Radiology Lab (CIR), Department of Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Pattern Recognition and Image Processing Group, Department of Computer Aided Automation, Vienna University of Technology, Wiedner Hauptstrasse 8-10/020, A-1040 Vienna (Austria); Institute for Computer Graphics and Vision, Graz University of Technology, Inffeldgasse 16, A-8010 Graz (Austria); Birngruber, E. [Computational Image Analysis and Radiology Lab (CIR), Department of Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Thodberg, H.H. [Visiana Aps, Sollerodvej 57C, DK-2840 Holte (Denmark); Kainberger, F. [Computational Image Analysis and Radiology Lab (CIR), Department of Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Langs, G. [Computational Image Analysis and Radiology Lab (CIR), Department of Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)], E-mail: georg.langs@meduniwien.ac.at

    2009-11-15

    Recent years have brought rapid developments in computational image analysis in musculo-skeletal radiology. Meanwhile the algorithms have reached a maturity that makes initial clinical use feasible. Applications range from joint space measurement to erosion quantification, and from fracture detection to the assessment of alignment angles. Current results of computational image analysis in radiography are very promising, but some fundamental issues remain to be clarified, among which the definition of the optimal trade off between automatization and operator-dependency, the integration of these tools into clinical work flow and last not least the proof of incremental clinical benefit of these methods.

  4. Computational radiology in skeletal radiography

    Recent years have brought rapid developments in computational image analysis in musculo-skeletal radiology. Meanwhile the algorithms have reached a maturity that makes initial clinical use feasible. Applications range from joint space measurement to erosion quantification, and from fracture detection to the assessment of alignment angles. Current results of computational image analysis in radiography are very promising, but some fundamental issues remain to be clarified, among which the definition of the optimal trade off between automatization and operator-dependency, the integration of these tools into clinical work flow and last not least the proof of incremental clinical benefit of these methods.

  5. X-ray fluorescence and computed radiography analysis of a famous brazilian painting from XIX century

    This work used Energy Dispersive X-Ray Fluorescence (EDXRF) and Computed Radiography (CR) to evaluate the general conditions of the painting 'Gioventu' (Eliseu Visconti, 1898), identifying possible problems, areas that revealed signs of previous retouchings and the pigments used by the artist. EDXRF measurements were carried out with a portable system consisting of an X-ray tube Oxford TF3005 with W anode, operating at 25 kV and 100 μA, and a Si-PIN XR-100CR detector from Amptek. Several spectra were obtained in each color, with an acquisition time of 300 s and a beam collimation of 2 mm. The spectra were analyzed using the software QXAS-AXIL (IAEA). The results revealed that the drawings were made over a preparatory layer of lead white. Some pigments identified were: yellow, red and brown ochre; umbra; vermilion; cobalt blue; etc. The experimental setup used in the CR analysis consisted of an Oxford X-ray source, operating at 50 kV and 200 μA, placed at 85 cm from the painting, a GE CR 50P portable computed radiography scanner and a Fuji imaging plate detector. The exposure time was 600 s. The radiographic images revealed that the painting was in a good state of conservation and also a complete composition hidden underneath the visible paint layer.(author)

  6. X-ray fluorescence and computed radiography analysis of a famous brazilian painting from XIX century

    Calza, Cristiane; Oliveira, Davi F.; Rocha, Henrique S.; Lopes, Ricardo Tadeu [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear], e-mail: ccalza@lin.ufrj.br; Pedreira, Andrea [Museu Nacional de Belas Artes, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    This work used Energy Dispersive X-Ray Fluorescence (EDXRF) and Computed Radiography (CR) to evaluate the general conditions of the painting 'Gioventu' (Eliseu Visconti, 1898), identifying possible problems, areas that revealed signs of previous retouchings and the pigments used by the artist. EDXRF measurements were carried out with a portable system consisting of an X-ray tube Oxford TF3005 with W anode, operating at 25 kV and 100 {mu}A, and a Si-PIN XR-100CR detector from Amptek. Several spectra were obtained in each color, with an acquisition time of 300 s and a beam collimation of 2 mm. The spectra were analyzed using the software QXAS-AXIL (IAEA). The results revealed that the drawings were made over a preparatory layer of lead white. Some pigments identified were: yellow, red and brown ochre; umbra; vermilion; cobalt blue; etc. The experimental setup used in the CR analysis consisted of an Oxford X-ray source, operating at 50 kV and 200 {mu}A, placed at 85 cm from the painting, a GE CR 50P portable computed radiography scanner and a Fuji imaging plate detector. The exposure time was 600 s. The radiographic images revealed that the painting was in a good state of conservation and also a complete composition hidden underneath the visible paint layer.(author)

  7. Analysis of the painting 'Gioventu' (Eliseu Visconti) using EDXRF and computed radiography

    EDXRF and Computed Radiography were used to evaluate the general conditions of the painting 'Gioventu' (Eliseu Visconti, 1898), identifying possible problems, areas that revealed signs of previous retouchings and the pigments used by the artist. EDXRF measurements were carried out with a portable system consisting of an X-ray tube Oxford TF3005 with W anode, operating at 25 kV and 100 μA, and a Si-PIN XR100CR detector from Amptek. Several spectra were obtained in each color, with an acquisition time of 300 s and a beam collimation of 2 mm. The spectra were processed and analyzed using the software QXAS-AXIL (IAEA). The results revealed that the drawings were made over a preparatory layer of lead white. Some pigments identified were: yellow, red and brown ochre; umbra; vermilion; cobalt blue; etc. The experimental setup used in the CR analysis consisted of an Oxford X-ray source, operating at 50 kV and 200 A, placed at 85 cm from the painting, a GE CR 50P Portable Computed Radiography Scanner and a Fuji Imaging Plate detector. The exposure time was 600 s. The radiographic images revealed that the painting was in a good state of conservation

  8. Comparison of film digitization and computed radiography for quantitative analysis of lung texture

    The authors are developing an automated computerized scheme to quantify interstitial diseases by using physical measure of lung textures in chest radiographs. In order to implement this scheme for practical use, the authors are investigating the effect of different digital systems on the performance of this scheme. Chest images of the same patients were obtained with conventional film and a computed radiography (CR) system. Texture measures were determined by digitization of chest radiographs with a drum scanner (0.1-mm pixel size) and laser scanner (0.175-mm pixel size), as well as from digital images with CR system (0.2mm pixel size). Receiver operating characteristic curves for detection of interstitial disease obtained with three digital system are compared together with analysis of their imaging properties

  9. Computed radiography in NDT applications

    Computed Radiography, or digital radiography by use of reusable Storage Phosphor screens, offers a convenient and reliable way to replace film. In addition to the reduced cost on consumables, the return on investment of CR systems is strongly determined by savings in exposure time, processing times and archival times. But also intangible costs like plant shutdown, environment safety and longer usability of isotopes are increasingly important when considering replacing film by Storage Phosphor systems. But more than in traditional radiography, the use of digital images is a trade-off between the speed and the required quality. Better image quality is obtained by longer exposure times, slower phosphor screens and higher scan resolutions. Therefore, different kinds of storage phosphor screens are needed in order to cover every application. Most operations have the data, associated with the tests to be performed, centrally stored in a database. Using a digital radiography system gives not only the advantages of the manipulation of digital images, but also the digital data that is associated with it. Smart methods to associate cassettes and Storage screens with exposed images enhance the workflow of the NDT processes, and avoid human error. Automated measurements tools increase the throughput in different kinds of operations. This paper gives an overview of the way certain operations have decided to replace film by Computed Radiography, and what the major benefits for them have been. (author)

  10. Computed radiography in NDT application

    Computed Radiography, or digital radiography by use of reusable Storage Phosphor screens, offers a convenient and reliable way to replace film. In addition to the reduced cost on consumables, the return on investment of CR systems is strongly determined by savings in exposure time, processing times and archival times. But also intangible costs like plant shutdown, environment safety and longer usability of isotopes are increasingly important when considering replacing film by Storage Phosphor systems. But mote than in traditional radiography, the use of digital images is a trade-off between the speed and the required quality. Better image quality is obtained by longer exposure times, slower phosphor screens and higher scan resolutions. Therefore, different kinds of storage phosphor screens are needed in order to cover every application. Most operations have the data, associated with the tests to be performed, centrally stored in a database. Using a digital radiography system gives not only the advantages of the manipulation of digital images, but also the digital data that is associated with it. Smart methods to associate cassettes and Storage screens with exposed images enhance the workflow of the NDT processes, and avoid human error. Automated measurements tools increase the throughput in different kinds of operations. This paper gives an overview of the way certain operations have decided to replace film by Computed Radiography, and what the major benefits for them have been.

  11. Analysis of edentulous maxillae using computed tomography and panoramic radiography in the surgical planning of dental implants

    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)

  12. 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.

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

    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

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

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

  15. Corrosion Surveillance In Pipe By Computed Radiography

    Computed Radiography (CR) is a technique of digital industrial radiology which is developed to replace conventional radiography. With a CR system, the detection of the outer and inner wall surface of the pipe is done usually by edge detection and filter algorithms of the profile line at the position under investigation. Applying in industries, radiographic examination shall be performed in accordance with a written procedure. This paper summarizes collected knowledge and experimental results to establish a procedure for radiography applications in monitoring corrosion in small bore pipes. (author)

  16. Clinical application of computed radiography

    Observer performance tests were performed to compare the diagnostic accuracy of digitized storage phosphors and conventional radiography in the detection of microcalcification in the breast and pulmonary nodules. Clustered microcalcifications (0.125-0.177 mm, 0.210-0.250 mm) were randomly superimposed on a human breast specimen. Two types of screen-film systems (Toshiba MM6/Fuji MINC, Kodak MinR/Kodak MinR) and CR images either with unsharp mask or with no image processing (unprocess) were used as imaging systems. Nine readers assessed the capability of screen-films, and unsharp-masked and unprocessed mammograms to detect microcalcifications. Observer performance data were evaluated by receiver operating characteristics (ROC) analysis. Both the area under ROC curve and the true positive localization fraction were used as performance indexes. Two screen-film images provided a higher detectability of microcalcifications than CR images. In the detectability of microcalcifications, unsharp-masked images were superior to unprocessed images, with no statistically significant difference. CR images showed higher false positive fraction than screen-film systems. To assess the detectability of pulmonary nodules, 15 radiologists compared the diagnostic accuracy of screen-film system and CR images, including unprocessed, unsharp-masked, reversed and paired images, in 18 normal volunteers and 18 patients with pulmonary nodules. Overall diagnostic accuracy of CR images, except for reversed images, were comparable to the screen-film system. In case of definite, large nodules, unprocessed, unsharp-masked, and paired images were superior to the screen-film and reversed images. Screen-film and unprocessed images were helpful in cases of tiny nodules without definite contrast. The detectability of pulmonary nodules may be affected by image processing conditions, radiologist' experiences, and characteristics of nodules themselves. (N.K.) 59 refs

  17. Comparison of flat-panel radiography and computed radiography in urography

    Purpose: To evaluate the diagnostic value of digital flat-panel radiography in uro-radiology the i.v. urograms of patients who had been examined with computed radiography and digital flat-panel radiography were compared regarding image quality. Methods: 50 patients who underwent clinically indicated i.v. urography were examined with digital flat-panel radiography and computed radiography. In order to avoid unnecessary double exposure to X-rays, patients were examined either by flat-panel or computed radiography before injection of contrast media. Each further clinically indicated exposure after administration of contrast media was done by alternating the other examination technique. The digital images were compared by 4 radiologists regarding image quality for the detection of defined anatomic structures. Results: Digital flat-panel radiography showed an image quality of the liver, spleen and both kidneys that was similar to computed radiography. The urinary tract, lumbar spine, pelvis and psoas muscle were significantly better visible on flat-panel radiography images. Conclusions: Compared to computed radiography there is no loss of image information by using digital flat-panel radiography in uro-radiology. On the contrary, some anatomic structures on abdominal survey images show better image quality. In conclusion, digital flat-panel radiography has the potential to replace computed radiography in uroradiologic examinations. (orig.)

  18. Computed radiography- the state of the art

    Despite the advantages obtained with the radiographic inspection, the risks inherent to the exposure of ionizing radiations not always represented the major limiters regarding the employment of the technique. However, with the arrival of the computed radiography, the industrial radiology gets space again due to the benefits provided by the new technology, among which the following are outstanding: possibility of reduction of the time of radiography exposure and, consequently, of the marking area, direct acquisition of images, reduction of consumables and chemical waste and possibility of using again the detectors (imaging plates). Before such a favorable scenario, the computed radiography is being highlighted as the solution for almost all the problems, even without the full knowledge of its advantages and restrictions. This work briefly presents the state of the art related with the industrial applications (in-service inspection of wall loss and weld inspection) and the limitations noticed up to the moment are discussed. (author)

  19. Use of computed radiography for portal imaging

    This paper compares image quality of conventional film based portal images with the quality of portal images based on computed radiography (CR). The paper concludes that portal imaging with CR imaging plates instead of the conventional film provides images which have a significantly higher image quality. CR based portal images permit better visualization of important landmarks

  20. Integrating computer aided radiography and plantar pressure measurements for complex gait analysis

    Radiographic Fluoroscopy (DRF) and Contact Pressure Display (CPD). The CPD method uses a birefiingent integrated optical sandwich for contact stress analysis, e.g. plantar pressure distribution. The DRF method displays and electronically records skeletal motion using X-ray radiation, providing the exact bone and joint positions during gait. Integrating the two techniques, contribution of each segment to the HFS behavior may be studied by applying image processing and analysis techniques. The combined resulted data may be used not only to detect and diagnose gait pathologies but also as a base for development of advanced numerical models of the foot structure

  1. Pepper seed germination assessed by combined X-radiography and computer-aided imaging analysis

    A lot of pepper seeds having 87% germination were subjected to X-ray inspection using a non lethal dose of radiation. Seeds with less than 2.7% (on the basis of total seed area) of free space area, i.e. the spaces between embryo and endosperm, were classified as highly viable seeds (97-100% germination) with the lowest level of abnormal seedlings. Seeds X-ray classified as good were subjected to a computerised image analysis to study seed imbibition and radicle elongation. The patterns of seed area increase, chosen as the most accurate indicator of seed swelling, resembled the triphasic curve of water uptake. The first phase was completed at 9 h followed by a second phase that varied widely in time until completion of germination between 52 and 96 h. The proportion of seeds with radicle protrusion between 52-56 h and 64-72 h assessed with the image analysis was significantly higher than that recorded using a conventional germination test. In addition, the rate of increase of seed area during the third phase of imbibition, mostly due to protrusion of the radicle tip and its growth, was highly correlated with the corresponding radicle elongation rate

  2. Computed vs. film-screen magnification radiography of fingers in hyperparathyroidism. An ROC analysis

    One hundred randomly selected patients with suspected or known hyperparathyroidism were examined in a prospective study of the 2nd and 3rd fingers with film-screen and digital luminescence radiographs using magnification technique. The digital images were displayed on a work-station and printed as hard-copies. Two radiologists evaluated the film-screen images regarding subperiosteal and intracortical resorption and their results were defined as ''gold standard'' regarding the absence or presence of these changes. Four radiologists evaluated these changes in the 3 image forms and an ROC analysis was performed. Comparing the areas under the ROC curves to significant difference was found between the film-screen images and the 2 digital display forms. These results suggest that currently available digital systems provide adequate diagnostic accuracy for evaluation of subtle skeletal changes. (orig.)

  3. Introduction of computed radiography in two mammography services: image quality and dose analysis

    This study has evaluated the impact of the introduction of CR technology in the routine of two mammography services operating with Lorad Affinity X-ray units and CR Fuji Profect One system. Mean glandular dose was determined to set Automatic Exposure Control parameters according to optimal image quality. Reject analysis of patient images was made to establish the overall impact in routine work. As regards to dose evaluation, the results show that in 44% of mammography exams the MGD were above action levels. It is due to inadequate AEC adjustment and insufficient training of the staff in operating CR systems. In addition, common errors with screen/film systems like wrong breast positing and selection of exposure parameters, as well as X-ray unit failures like insufficient anti scatter grid movement still occurs. This is an indication that ongoing efforts should be concentrated in the constancy of AEC adjustment for CR image plates and staff training. Until now, brazilian health authorities did not implement any program to evaluate digital systems performance, but efforts are being done in order to provide guidelines to breast screening aiming the control of breast dose compatible with optimal image quality. (author)

  4. Introduction of computed radiography in two mammography services: Image quality and dose analysis

    This study has evaluated the impact of the introduction of CR technology in the routine of two mammography services operating with Lorad Affinity x-ray units and CR Fuji Profect One system. Mean glandular dose was determined to set Automatic Exposure Control parameters according to optimal image quality. Reject analysis of patient images was made to establish the overall impact in routine work. As regards to dose evaluation, the results show that in 44% of mammography exams the MGD were above action levels. It is due to inadequate AEC adjustment and insufficient training of the staff in operating CR systems. In addition, common errors with screen/film systems like wrong breast positing and selection of exposure parameters, as well as x-ray unit failures like insufficient anti scatter grid movement still occurs. This is an indication that ongoing efforts should be concentrated in the constancy of AEC adjustment for CR image plates and staff training. Until now, brazilian health authorities did not implement any program to evaluate digital systems performance, but efforts are being done in order to provide guidelines to breast screening aiming the control of breast dose compatible with optimal image quality. (author)

  5. Optimization and quality control of computed radiography

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

    1994-05-01

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

  6. Computed radiography simulation using the Monte Carlo code MCNPX

    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. (author)

  7. The art of rejection: Comparative analysis between Computed Radiography (CR) and Digital Radiography (DR) workstations in the Accident & Emergency and General radiology departments at a district general hospital using customised and standardised reject criteria over a three year period

    Aims: Reject analysis continues to play an integral part of a Quality Assurance (QA) program. This study aims to show how Computed Radiography (CR) and Digital Radiography (DR) reject analysis data can be customised by the user to aid in the interpretation of exported data and identify trends and issues relating to technique and training. Materials and methods: Reject analysis was reviewed for the period of 2011–2014 using exported data from CR and DR systems in the Accident and Emergency (A&E) and General radiology departments at a district general hospital. Reject criteria was customised to departmental needs and standardised across all workstation's with monthly data collection for amalgamation onto a central spreadsheet. Results: Analysis by workstation and department was performed with regards to total number of exposure events, rejects and reject ratios (%) and reasons for film rejection (positional and exposure) were reviewed. Annual overall reject ratios (%) were shown to be on average within levels acceptable by the World Health Organisation (WHO)1 with some variability on monthly basis according to workloads experienced. Conclusions: A number of improvements have been suggested to improve data reliability for future analysis and the continuation of a review of the physical rejected image is recommended as this can highlight problematic areas and help to reveal trends which pure data cannot show. - Highlights: • Retrospective analysis of three years CR/DR rejects using customised QA program. • Reviewed data by individual workstations and departments. • Highlighted trends between workstations and departments. • Overall annual reject rates shown to be within WHO recommendations. • Recommendations for future improvements for reject analysis within department and continued review of JPEG images

  8. Radiological protection procedures for industrial applications of computed radiography

    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)

  9. Multidimensional analysis in industrial radiography

    EDF uses non-destructive testing by X or gamma-ray radiography for routine nozzle inspection in nuclear power plants. The images obtained are examined by radiographic specialists in order to detect, identify and quantify any defects, but the quality of the radiograms and the small size of the defects make their work extremely difficult. It is for these reasons that EDF developed ENTRAIGUES, a digital package for the processing and aid in interpretation of images generated by radiographical inspections, aimed at: -digitizing the radiographic films to be appraised, - facilitating analysis of the digitized radiograms. Defect orientation is estimated by 3D reconstruction of the component being inspected, based on a limited number of its projections. (authors). 11 figs., 6 refs

  10. Computed radiography imaging plates and associated methods of manufacture

    Henry, Nathaniel F.; Moses, Alex K.

    2015-08-18

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

  11. Computer radiography-X-ray with vision

    Computer radiography describes an entire process of creating a digital image including acquiring, processing, presenting and managing the image data. the cassettes are special in that they use an imaging plate instead of films. the imaging plate is coated with storage phosphors which captures x-ray as they pass through the patient. the imaging plate is read with a bar code reader and the imaging plate number recorded in the computer. The cassette is then loaded in the reader unit where it is read using infra-red light which excites the particles on the plate which in turn illuminates and picked by photo-sensors which converts the signal into digital pulses. the pulses then run through a board which converts it into an image which is then displayed on the control console. The plate then runs through the erasure section where it is exposed to yellow light, which erases the plate. The IP is then put back in the cassette and locked and can be reused for the next episode

  12. Analysis on imaging features of mammography in computer radiography and investigation on gray scale transform and energy subtraction

    In this dissertation, a novel transform method based on human visual response features for gray scale mammographic imaging in computer radiography (CR) is presented. The parameters for imaging quality on CR imaging for mammography were investigated experimentally. In addition, methods for image energy subtraction and a novel method of image registration for mammography of CR imaging are presented. Because the images are viewed and investigated by humans, the method of displaying differences in gray scale images is more convenient if the gray scale differences are displayed in a manner commensurate with human visual response principles. Through transformation of image gray scale with this method, the contrast of the image will be enhanced and the capability for humans to extract the useful information from the image will be increased. Tumors and microcalcifications are displayed in a form for humans to view more simply after transforming the image. The method is theoretically and experimentally investigated. Through measurement of the parameters of a geometrically blurred image, MTF, DQE, and ROC on CR imaging, and also comparison with the imaging quality of screen-film systems, the results indicate that CR imaging qualities in DQE and ROC are better than those of screen-film systems. In geometric blur of the image and MTF, the differences in image quality between CR and the screen-film system are very small. The results suggest that the CR system can replace the screen-film system for mammography imaging. In addition, the results show that the optimal imaging energy for CR mammography is about 24 kV. This condition indicates that the imaging energy of the CR system is lower than that of the screen-film system and, therefore, the x-ray dose to the patient for mammography with the CR system is lower than that with the screen-film system. Based on the difference of penetrability of x ray with different wavelength, and the fact that the part of the x-ray beam will pass

  13. Evaluation and testing of computed radiography systems

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

  14. Evaluation and testing of computed radiography systems.

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

    2005-01-01

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

  15. Performance evaluation of computed radiography systems

    Recommended methods to test the performance of computed radiography (CR) digital radiographic systems have been recently developed by the AAPM Task Group No. 10. Included are tests for dark noise, uniformity, exposure response, laser beam function, spatial resolution, low-contrast resolution, spatial accuracy, erasure thoroughness, and throughput. The recommendations may be used for acceptance testing of new CR devices as well as routine performance evaluation checks of devices in clinical use. The purpose of this short communication is to provide a tabular summary of the tests recommended by the AAPM Task Group, delineate the technical aspects of the tests, suggest quantitative measures of the performance results, and recommend uniform quantitative criteria for the satisfactory performance of CR devices. The applicability of the acceptance criteria is verified by tests performed on CR systems in clinical use at five different institutions. This paper further clarifies the recommendations with respect to the beam filtration to be used for exposure calibration of the system, and the calibration of automatic exposure control systems

  16. Image analysis in industrial radiography

    Non-destructive testing in nuclear power plants remains a major EDF objective for the coming decades. To facilitate diagnosis, the expert must be provided with elaborate decision-making aids: contrasted images, noise-free signals, pertinent parameters, ''meaningful'' images. In the field of industrial radiography, the inspector's offer of a portable system for digitalization and subsequent processing of radiographs (ENTRAIGUES) is an improvement in the inspection of primary circuit nozzles. Three major directions were followed: - improvement of images and localization of flaws (2D approach); techniques such as Markov modelling were evaluated and tested, - development of a system which can be transported on site, for digitalization, processing and subsequent archiving on inspection radiographs, known as ENTRAIGUES, - development of a program for aid in analysis of digitized radiographs (''bread-board'' version), offering an ergonomic interface and push-button processing, which is the software component in ENTRAIGUES and uses sophisticated methods: contrast enhancement, background flattening, segmentation. An other objective is to reconstruct a three-dimensional volume on the basis of a few radiographs taken at different incidences and to estimate the flaw orientation within a piece understudy. This information makes sense to experts, with regards to the deterioration rate of the flaw; the equipment concerned includes the formed bends in the primary coolant nozzles. This reconstruction problem is ill-posed and a solution can be obtained by introducing a priori information on the solution. The first step of our algorithm is a classical iterative reconstruction A.R.T. type method (Algebraic Reconstruction Techniques) which provides a rough volumic reconstructed tridimensional zone containing the flaw. Then, on this reconstructed zone, we apply a Bayesian restoration method introducing a Markov Random Field (MRF) modelling. Conclusive results have been obtained. (author

  17. Extremity exams optimization for computed radiography

    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)

  18. Chest X ray effective doses estimation in computed radiography

    Conventional chest radiography is technically difficult because of wide in tissue attenuations in the chest and limitations of screen-film systems. Computed radiography (CR) offers a different approach utilizing a photostimulable phosphor. photostimulable phosphors overcome some image quality limitations of chest imaging. The objective of this study was to estimate the effective dose in computed radiography at three hospitals in Khartoum. This study has been conducted in radiography departments in three centres Advanced Diagnostic Center, Nilain Diagnostic Center, Modern Diagnostic Center. The entrance surface dose (ESD) measurement was conducted for quality control of x-ray machines and survey of operators experimental techniques. The ESDs were measured by UNFORS dosimeter and mathematical equations to estimate patient doses during chest X rays. A total of 120 patients were examined in three centres, among them 62 were males and 58 were females. The overall mean and range of patient dosed was 0.073±0.037 (0.014-0.16) mGy per procedure while the effective dose was 3.4±01.7 (0.6-7.0) mSv per procedure. This study compared radiation doses to patients radiographic examinations of chest using computed radiology. The radiation dose was measured in three centres in Khartoum- Sudan. The results of the measured effective dose showed that the dose in chest radiography was lower in computed radiography compared to previous studies.(Author)

  19. A methodology for radiological accidents analysis in industrial gamma radiography

    A critical review of 34 published severe radiological accidents in industrial gamma radiography, that happened in 15 countries, from 1960 to 1988, was performed. The most frequent causes, consequences and dose estimation methods were analysed, aiming to stablish better procedures of radiation safety and accidents analysis. The objective of this work is to elaborate a radiological accidents analysis methodology in industrial gamma radiography. The suggested methodology will enable professionals to determine the true causes of the event and to estimate the dose with a good certainty. The technical analytical tree, recommended by International Atomic Energy Agency to perform radiation protection and nuclear safety programs, was adopted in the elaboration of the suggested methodology. The viability of the use of the Electron Gamma Shower 4 Computer Code System to calculate the absorbed dose in radiological accidents in industrial gamma radiography, mainly at sup(192)Ir radioactive source handling situations was also studied. (author)

  20. Real-time radiography, digital radiography, and computed tomography for nonintrusive waste drum characterization

    We are investigating and developing the application of x-ray nondestructive evaluation (NDE) and gamma-ray nondestructive assay (NDA) methods to nonintrusively characterize 208-liter (55-gallon) mixed waste drums. Mixed wastes contain both hazardous and radioactive materials. We are investigating the use of x-ray NDE methods to verify the content of documented waste drums and determine if they can be used to identify hazardous and nonconforming materials. These NDE methods are also being used to help waste certification and hazardous waste management personnel at LLNL to verify/confirm and/or determine the contents of waste. The gamma-ray NDA method is used to identify the intrinsic radioactive source(s) and to accurately quantify its strength. The NDA method may also be able to identify some hazardous materials such as heavy metals. Also, we are exploring techniques to combine both NDE and NDA data sets to yield the maximum information from these nonintrusive, waste-drum characterization methods. In this paper, we report an our x-ray NDE R ampersand D activities, while our gamma-ray NDA activities are reported elsewhere in the proceedings. We have developed a data, acquisition scanner for x-ray NDE real-time radiography (RTR), as well as digital radiography transmission computed tomography (TCT) along with associated computational techniques for image reconstruction, analysis, and display. We are using this scanner and real-waste drums at Lawrence Livermore National Laboratory (LLNL). In this paper, we discuss some issues associated with x-ray imaging, describe the design construction of an inexpensive NDE drum scanner, provide representative DR and TCT results of both mock- and real-waste drums, and end with a summary of our efforts and future directions. The results of these scans reveal that RTR, DR, and CT imaging techniques can be used in concert to provide valuable information about the interior of low-level-, transuranic-, and mock-waste drums without

  1. Noise analysis of a digital radiography system

    The sources of noise in a digital video subtraction angiography system were identified and analyzed. Signal-to-noise ratios of digital radiography systems were measured using the digital image data recorded in the computer. The major sources of noise include quantum noise, TV camera electronic noise, quantization noise from the analog-to-digital converter, time jitter, structure noise in the image intensifier, and video recorder electronic noise. A new noise source was identified, which results from the interplay of fixed pattern noise and the lack of image registration. This type of noise may result from image-intensifier structure noise in combination with TV camera time jitter or recorder time jitter. A similar noise source is generated from the interplay of patient absorption inhomogeneities and patient motion or image re-registration. Signal-to-noise ratios were measured for a variety of experimental conditions using subtracted digital images. Image-intensifier structure noise was shown to be a dominant noise source in unsubtracted images at medium to high radiation exposure levels. A total-system signal-to-noise ratio (SNR) of 750:1 was measured for an input exposure of 1 mR/frame at the image intensifier input. The effect of scattered radiation on subtracted image SNR was found to be greater than previously reported. The detail SNR was found to vary approximately as one plus the scatter degradation factor. Quantization error noise with 8-bit image processors (signal-to-noise ratio of 890:1) was shown to be of increased importance after recent improvements in TV cameras. The results of the analysis are useful both in the design of future digital radiography systems and the selection of optimum clinical techniques

  2. Collaboration in radiography: A bibliometric analysis

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

  3. 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. PMID:2233574

  4. Artifacts Found During Quality Assurance Testing of Computed Radiography and Digital Radiography Detectors

    Honey, Ian D.; MacKenzie, Alistair

    2008-01-01

    A series of artifact images, obtained over 5 years of performance testing, of both computed radiography (CR) and integrated digital radiographic X-ray imaging detectors are presented. The images presented are all either flat field or test object images and show artifacts previously either undescribed in the existing literature or meriting further comment. The artifacts described are caused by incorrect flat field corrections, a failing amplifier, damaged detector lines affecting their neighbo...

  5. 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)

  6. Computer-aided recognition of emphysema on digital chest radiography.

    Miniati, Massimo; Coppini, Giuseppe; Monti, Simonetta; Bottai, Matteo; Paterni, Marco; Ferdeghini, Ezio Maria

    2011-01-01

    Background Computed tomography (CT) is the benchmark for diagnosis emphysema, but is costly and imparts a substantial radiation burden to the patient. Objective To develop a computer-aided procedure that allows recognition of emphysema on digital chest radiography by using simple descriptors of the lung shape. The procedure was tested against CT. Methods Patients (N=225), who had undergone postero-anterior and lateral digital chest radiographs and CT for diagnostic purposes, were studied and ...

  7. Control dose in chest radiography after the installation of the computed radiography

    The aim of this work is to verify patient does after the installation of the computed radiography. Entrance surface doses were obtained from a measurement of the output of the x-ray tube and exposure factor used at posteroanterior (PA) and lateral (LAT) chest in 50 adult patients before and after the installation. The obtained average values were 0.28±0.10mGy in the PA view and 0.8±0.5 mGy in the LAT view with the conventional screen-film system 0.27±0.06 mGy in PA view and 0.69±0.18 mGy in LAT view with the digital radiography system. The results do not exceed the diagnostic reference levels (DRLs) and are constant after the change of system. (Author)

  8. Computed radiography dose optimization in pediatric patients

    Radiation dose reduction in pediatric X-ray imaging is especially important because of children radiation sensitivity. For any radiographic examination performed at a fixed radiographic tube potential, the patient absorbed dose is directly proportional to the value of milliampere-seconds (mAs) selected by the operator. Nevertheless, reducing X-ray exposure has the unavoidable disadvantage of increasing the quantum noise in the resultant image. The objective of this work is to identify the minimum tube current setting required for maintaining accurate examinations, to modify, if required, the daily protocols applied at La Fe de Valencia University Hospital. To accomplish this goal, a noise addition software has been developed in order to study the diagnostic accuracy as a function of reducing dose by artificially increasing the image noise. The noise addition tool has been applied to several thorax images acquired from pediatric unit to simulate new lower dose radiographies and allow medical researchers to study how lower dose affects the patient pneumonia diagnosis. (author)

  9. Computed radiography dose optimization in pediatric patients

    Radiation dose reduction in pediatric X-ray imaging is especially important because of children radiation sensitivity. For any radiographic examination performed at a fixed radiographic tube potential, the patient absorbed dose is directly proportional to the value of milliampere-seconds (mAs) selected by the operator. Nevertheless, reducing X-ray exposure has the unavoidable disadvantage of increasing the quantum noise in the resultant image. The objective of this work is to identify the minimum tube current setting required for maintaining accurate examinations, to modify, if required, the daily protocols applied at La Fe de Valencia Universitary Hospital. To accomplish this goal, a noise addition software has been developed in order to study the diagnostic accuracy as a function of reducing dose by artificially increasing the image noise. The noise addition tool has been applied to several thorax images acquired from pediatric unit to simulate new lower dose radiographies and allow medical researchers to study how lower dose affects the patient pneumonia diagnosis. (author)

  10. Physical image quality of computed radiography in mammography system

    Full-text: Mammography is a screening procedure that mostly used for early detection of breast cancer. In digital imaging system, Computed Radiography is a cost-effective technology that applied indirect conversion detector. The paper presents physical image quality parameter measurements namely modulation transfer function (MTF), normalized noise power spectrum (NNPS) and detective quantum efficiency (DQE) of Computed Radiography in mammography system. MTF was calculated from two different orientations of slanted images of an edge test device and NNPS was estimated using flat-field image. Both images were acquired using a standard mammography beam quality. DQE was determined by applying the MTF and NNPS values into our developed software program. Both orientations have similar DQE characteristics. (author)

  11. Impeller Metrology for Pipeline Compressors Using Computed Radiography

    A new, quantitative method is described to measure features in pipeline impellers using computed radiography (CR). This capability, with an accuracy approaching 5 mils, is required to optimize the impeller design for high efficiency. The large area coverage, simplicity, and high spatial resolution of CR are ideal for this application. A novel phantom and image processing algorithm chain was used to demonstrate measurement repeatability of 99.9% (1 mil) using CR

  12. Computer-aided recognition of emphysema on digital chest radiography

    Background: Computed tomography (CT) is the benchmark for diagnosis emphysema, but is costly and imparts a substantial radiation burden to the patient. Objective: To develop a computer-aided procedure that allows recognition of emphysema on digital chest radiography by using simple descriptors of the lung shape. The procedure was tested against CT. Methods: Patients (N = 225), who had undergone postero-anterior and lateral digital chest radiographs and CT for diagnostic purposes, were studied and divided in a derivation (N = 118) and in a validation sample (N = 107). CT images were scored for emphysema using the picture-grading method. Simple descriptors that measure the bending characteristics of the lung profile on chest radiography were automatically extracted from the derivation sample, and applied to train a neural network to assign a probability of emphysema between 0 and 1. The diagnostic performance of the procedure was described by the area under the receiver operating characteristic curve (AUC). Results: AUC was 0.985 (95% confidence interval, 0.965-0.998) in the derivation sample, and 0.975 (95% confidence interval, 0.936-0.998) in the validation sample. At a probability cutpoint of 0.55, the procedure yielded 92% sensitivity and 96% specificity in the derivation sample; 90% sensitivity and 97% specificity in the validation sample. False negatives on chest radiography had trace or mild emphysema on CT. Conclusions: The computer-aided procedure is simple and inexpensive, and permits quick recognition of emphysema on digital chest radiographs.

  13. Computer-aided recognition of emphysema on digital chest radiography

    Miniati, Massimo, E-mail: Massimo.Miniati@unifi.it [Department of Medical and Surgical Critical Care, University of Florence, 50134 Florence (Italy); Coppini, Giuseppe; Monti, Simonetta [Institute of Clinical Physiology, National Research Council, 56124 Pisa (Italy); Bottai, Matteo [Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, 17177 Stockholm (Sweden); Division of Biostatistics, Arnold School of Public Health, University of South Carolina, 29208 Columbia, SC (United States); Paterni, Marco; Ferdeghini, Ezio Maria [Institute of Clinical Physiology, National Research Council, 56124 Pisa (Italy)

    2011-11-15

    Background: Computed tomography (CT) is the benchmark for diagnosis emphysema, but is costly and imparts a substantial radiation burden to the patient. Objective: To develop a computer-aided procedure that allows recognition of emphysema on digital chest radiography by using simple descriptors of the lung shape. The procedure was tested against CT. Methods: Patients (N = 225), who had undergone postero-anterior and lateral digital chest radiographs and CT for diagnostic purposes, were studied and divided in a derivation (N = 118) and in a validation sample (N = 107). CT images were scored for emphysema using the picture-grading method. Simple descriptors that measure the bending characteristics of the lung profile on chest radiography were automatically extracted from the derivation sample, and applied to train a neural network to assign a probability of emphysema between 0 and 1. The diagnostic performance of the procedure was described by the area under the receiver operating characteristic curve (AUC). Results: AUC was 0.985 (95% confidence interval, 0.965-0.998) in the derivation sample, and 0.975 (95% confidence interval, 0.936-0.998) in the validation sample. At a probability cutpoint of 0.55, the procedure yielded 92% sensitivity and 96% specificity in the derivation sample; 90% sensitivity and 97% specificity in the validation sample. False negatives on chest radiography had trace or mild emphysema on CT. Conclusions: The computer-aided procedure is simple and inexpensive, and permits quick recognition of emphysema on digital chest radiographs.

  14. 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.

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

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

    2005-01-01

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

  16. Development of computer assisted learning program using cone beam projection for head radiography

    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. (author)

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

    Oberle, Renee

    2015-01-01

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

  18. High resolution digital radiography and three-dimensional computed tomography

    The predominant method used for radiographic inspection of aerospace hardware is film radiography, which is costly and time consuming. Each inspection requires many films to obtain successful viewing geometries under various x-ray conditions. Film radiography is also labor intensive, since the operator must place the film, expose it, remove it, and develop it before the images can be viewed or interpreted. In complex film inspections, it may not be possible to optimize the inspection because of the short periods allotted for nondestructive inspection (NDI). Storage and retrieval of the x-ray film is also rather cumbersome and labor intensive. Finally, film radiographs must be digitized and processed to extract quantitative information. Real-time radiographic (RTR) and near-real-time radiographic imaging systems offer solutions to some of the problems of film radiography. First, the operator can view the image immediately upon acquisition and thus optimize the inspection in a timely manner, and second, because the images are acquired electronically, the need for developing images is eliminated, and image analysis, storage, and retrieval are simplified. In this paper, the authors describe new solid-state x-ray camera system designs, the new scintillating glass and fiber-optic x-ray-to-light conversion screens, and their performance in x-ray tests. They compare the performance of these systems with that of x-ray image-intensifier tube systems and discuss the use of these new systems for acquisition of 3-D CT images

  19. Simplified techniques of cerebral angiography using a mobile X-ray unit and computed radiography

    Simplified techniques of cerebral angiography using a mobile X-ray unit and computed radiography (CR) are discussed. Computed radiography is a digital radiography system in which an imaging plate is used as an X-ray detector and a final image is displayed on the film. In the angiograms performed with CR, the spatial frequency components can be enhanced for the easy analysis of fine blood vessels. Computed radiography has an automatic sensitivity and a latitude-setting mechanism, thus serving as an 'automatic camera.' This mechanism is useful for radiography with a mobile X-ray unit in hospital wards, intensive care units, or operating rooms where the appropriate setting of exposure conditions is difficult. We applied this mechanism to direct percutaneous carotid angiography and intravenous digital subtraction angiography with a mobile X-ray unit. Direct percutaneous carotid angiography using CR and a mobile X-ray unit were taken after the manual injection of a small amount of a contrast material through a fine needle. We performed direct percutaneous carotid angiography with this method 68 times on 25 cases from August 1986 to December 1987. Of the 68 angiograms, 61 were evaluated as good, compared with conventional angiography. Though the remaining seven were evaluated as poor, they were still diagnostically effective. This method is found useful for carotid angiography in emergency rooms, intensive care units, or operating rooms. Cerebral venography using CR and a mobile X-ray unit was done after the manual injection of a contrast material through the bilateral cubital veins. The cerebral venous system could be visualized from 16 to 24 seconds after the beginning of the injection of the contrast material. We performed cerebral venography with this method 14 times on six cases. These venograms were better than conventional angiograms in all cases. This method may be useful in managing patients suffering from cerebral venous thrombosis. (J.P.N.)

  20. Tomosynthesis for the early detection of pulmonary emphysema: diagnostic performance compared with chest radiography, using multidetector computed tomography as reference

    Yamada, Yoshitake [Keio University School of Medicine, Department of Diagnostic Radiology, Tokyo (Japan); Nippon Koukan Hospital, Department of Radiology, Kawasaki-shi, Kanagawa (Japan); Jinzaki, Masahiro; Hashimoto, Masahiro; Shiomi, Eisuke; Kuribayashi, Sachio [Keio University School of Medicine, Department of Diagnostic Radiology, Tokyo (Japan); Abe, Takayuki [Keio University School of Medicine, Center for Clinical Research, Tokyo (Japan); Ogawa, Kenji [Nippon Koukan Hospital, Department of Radiology, Kawasaki-shi, Kanagawa (Japan)

    2013-08-15

    To compare the diagnostic performance of tomosynthesis with that of chest radiography for the detection of pulmonary emphysema, using multidetector computed tomography (MDCT) as reference. Forty-eight patients with and 63 without pulmonary emphysema underwent chest MDCT, tomosynthesis and radiography on the same day. Two blinded radiologists independently evaluated the tomosynthesis images and radiographs for the presence of pulmonary emphysema. Axial and coronal MDCT images served as the reference standard and the percentage lung volume with attenuation values of -950 HU or lower (LAA{sub -950}) was evaluated to determine the extent of emphysema. Receiver-operating characteristic (ROC) analysis and generalised estimating equations model were used. ROC analysis revealed significantly better performance (P < 0.0001) of tomosynthesis than radiography for the detection of pulmonary emphysema. The average sensitivity, specificity, positive predictive value and negative predictive value of tomosynthesis were 0.875, 0.968, 0.955 and 0.910, respectively, whereas the values for radiography were 0.479, 0.913, 0.815 and 0.697, respectively. For both tomosynthesis and radiography, the sensitivity increased with increasing LAA{sub -950}. The diagnostic performance of tomosynthesis was significantly superior to that of radiography for the detection of pulmonary emphysema. In both tomosynthesis and radiography, the sensitivity was affected by the LAA{sub -950}. (orig.)

  1. Tomosynthesis for the early detection of pulmonary emphysema: diagnostic performance compared with chest radiography, using multidetector computed tomography as reference

    To compare the diagnostic performance of tomosynthesis with that of chest radiography for the detection of pulmonary emphysema, using multidetector computed tomography (MDCT) as reference. Forty-eight patients with and 63 without pulmonary emphysema underwent chest MDCT, tomosynthesis and radiography on the same day. Two blinded radiologists independently evaluated the tomosynthesis images and radiographs for the presence of pulmonary emphysema. Axial and coronal MDCT images served as the reference standard and the percentage lung volume with attenuation values of -950 HU or lower (LAA-950) was evaluated to determine the extent of emphysema. Receiver-operating characteristic (ROC) analysis and generalised estimating equations model were used. ROC analysis revealed significantly better performance (P -950. The diagnostic performance of tomosynthesis was significantly superior to that of radiography for the detection of pulmonary emphysema. In both tomosynthesis and radiography, the sensitivity was affected by the LAA-950. (orig.)

  2. Assessing the impact of computed radiography and PACS

    The authors' institution is a VA pilot center for total digital imaging and PACS. They are gathering quantitative service delivery and cost data before, during, and after stepwise implementation of computed radiography and PACS at our institution to define the impact on imaging service delivery. They designed a simple audit method using the X-ray request and time clocks to determine patient waiting time, imaging time, film use, image availability to the radiologist, matching of current with previous images, image availability to clinicians, and time to final interpretation. Their department model is a multichannel, multiserver patient queue. Their current radiograph file is space limited. Their preimplementation audit showed some long waiting times (40 minutes, average 20) and immediate retrieval of prior films in only 42% of cases, with an average retrieval time of 22 hours. Computed radiography and the optical archive have the potential to improve these figures. The audit will be ongoing and automated as implementation of PACS progresses, to measure service improvement and learning curve with the new equipment. This paper presents the audit format and baseline preimplementation figures

  3. Assessing The Impact Of Computed Radiography And PACS

    Hedgcock, Marcus W.; Kehr, Katherine

    1989-05-01

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

  4. 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.)

  5. Conventional radiography and computed tomography of cardiac assist devices

    Patients intended for circulatory support by cardiac assist devices (CAD) usually suffer from end-stage acute or chronic heart failure. Since the introduction of CAD in 1963 by DeBakey and coworkers, the systems have gone through a substantial evolution and have been increasingly used in the intervening decades. The spectrum of CAD includes a variety of systems serving to assist the systolic function of the left ventricle, the right ventricle, or both. Conventional radiography and multislice spiral computed tomography (CT) are the most commonly used radiological techniques for imaging patients with a CAD. CT is very useful for evaluating CAD systems by using both two- and three-dimensional reconstructions of the volumetric data sets. The two techniques together allow for the comprehensive assessment of patients with devices by imaging the in- and outflow cannulae, the anastomoses, the position of the pump, as well as associated complications. A close collaboration with cardiac surgeons with expertise in the field of circulatory support is deemed necessary for adequate image interpretation. This article describes the technical diversity of the currently available CAD systems. The imaging characteristics on conventional radiography and multislice spiral CT as well as the typical complications of their use are demonstrated. (orig.)

  6. Research to exploit, utilize computed radiography system and build suitable process

    CR is computed radiography method. CR35 is digital radiography equipment which has just equipped in Viet Nam at the end of 2009 by VIE8020 project. The system include image plate (IP) to change for film, CR35 equipment which scans and records IPs signal by laser light and converts to digital image. This system can replaces of film radiography at any where has possible infrastructure like stable power supply, flat, etc. The research purpose is to use the CR35 system, own equipment and technology, compile technical documents and process guide for practice computed radiography. (author)

  7. Demonstration of neutron radiography and computed tomography at the University of Texas thermal neutron imaging facility

    A thermal neutron imaging facility for real-time neutron radiography and computed tomography has recently been developed and built at the University of Texas TRIGA reactor. Herein the authors present preliminary results of radiography and tomography test experiments. These preliminary results showed that the beam is of high quality and is suitable for radiography and tomography applications. A more detailed description of the facility is given elsewhere

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

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

  9. 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/). PMID:26974042

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

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

    2006-11-01

    The aim of this work was to study the dependence of image quality in digital chest and pelvis radiography on tube voltage, and to explore correlations between clinical and physical measures of image quality. The effect on image quality of tube voltage in these two examinations was assessed using two methods. The first method relies on radiologists' observations of images of an anthropomorphic phantom, and the second method was based on computer modeling of the imaging system using an anthropomorphic voxel phantom. The tube voltage was varied within a broad range (50-150 kV), including those values typically used with screen-film radiography. The tube charge was altered so that the same effective dose was achieved for each projection. Two x-ray units were employed using a computed radiography (CR) image detector with standard tube filtration and antiscatter device. Clinical image quality was assessed by a group of radiologists using a visual grading analysis (VGA) technique based on the revised CEC image criteria. Physical image quality was derived from a Monte Carlo computer model in terms of the signal-to-noise ratio, SNR, of anatomical structures corresponding to the image criteria. Both the VGAS (visual grading analysis score) and SNR decrease with increasing tube voltage in both chest PA and pelvis AP examinations, indicating superior performance if lower tube voltages are employed. Hence, a positive correlation between clinical and physical measures of image quality was found. The pros and cons of using lower tube voltages with CR digital radiography than typically used in analog screen-film radiography are discussed, as well as the relevance of using VGAS and quantum-noise SNR as measures of image quality in pelvis and chest radiography. PMID:17153395

  11. 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.

  12. Temporal digital subtraction radiography with a personal computer digital workstation

    Technique have been developed and implemented on a personal computer (PC)-based digital workstation to accomplish temporal digital subtraction radiography (TDSR). TDSR is useful in recording radiologic change over time. Thus, this technique is useful not only for monitoring chronic disease processes but also for monitoring the temporal course of interventional therapies. A PC-based digital workstation was developed on a PC386 platform with add-in hardware and software. Image acquisition, storage, and processing was accomplished using 512 x 512 x 8- or 12-bit frame grabber. Software and hardware were developed to accomplish image orientation, registration, gray scale compensation, subtraction, and enhancement. Temporal radiographs of the jaws were made in a fixed and reproducible orientation between the x-ray source and image receptor enabling TDSR. Temporal changes secondary to chronic periodontal disease, osseointegration of endosseous implants, and wound healing were demonstrated. Use of TDSR for chest imaging was also demonstrated with identification of small, subtle focal masses that were not apparent with routine viewing. The large amount of radiologic information in images of the jaws and chest may obfuscate subtle changes that TDSR seems to identify. TDSR appears to be useful as a tool to record temporal and subtle changes in radiologic images

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

    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)

  14. Digital radiography: are the manufacturers' settings too high? Optimisation of the Kodak digital radiography system with aid of the computed radiography dose index

    Manufacturers offer exposure indices as a safeguard against overexposure in computed radiography, but the basis for recommended values is unclear. This study establishes an optimum exposure index to be used as a guideline for a specific CR system to minimise radiation exposures for computed mobile chest radiography, and compares this with manufacturer guidelines and current practice. An anthropomorphic phantom was employed to establish the minimum milliamperes consistent with acceptable image quality for mobile chest radiography images. This was found to be 2 mAs. Consecutively, 10 patients were exposed with this optimised milliampere value and 10 patients were exposed with the 3.2 mAs routinely used in the department of the study. Image quality was objectively assessed using anatomical criteria. Retrospective analyses of 717 exposure indices recorded over 2 months from mobile chest examinations were performed. The optimised milliampere value provided a significant reduction of the average exposure index from 1840 to 1570 (p<0.0001). This new ''optimum'' exposure index is substantially lower than manufacturer guidelines of 2000 and significantly lower than exposure indices from the retrospective study (1890). Retrospective data showed a significant increase in exposure indices if the examination was performed out of hours. The data provided by this study emphasise the need for clinicians and personnel to consider establishing their own optimum exposure indices for digital investigations rather than simply accepting manufacturers' guidelines. Such an approach, along with regular monitoring of indices, may result in a substantial reduction in patient exposure. (orig.)

  15. Comparison of storage phosphor computed radiography with conventional film-screen radiography in the recognition of pneumoconiosis

    Laney, A.S.; Petsonk, E.L.; Wolfe, A.L.; Attfield, M.D. [National Institute of Occupational Safety & Health, Morgantown, WV (USA)

    2010-07-15

    Traditional film-screen radiography (FSR) has been useful in the recognition and evaluation of interstitial lung diseases, but is becoming increasingly obsolete. To evaluate the applicability of storage phosphor digital computed radiography (CR) images in the recognition of small lung opacities, we compared image quality and the profusion of small opacities between FSR and CR radiographs. We screened 1,388 working coal miners during the course of the study with FSR and CR images obtained on the same day from all participants. Each traditional chest film was independently interpreted by two of eight experienced readers using the International Labour Office (ILO) classification of radiographs of pneumoconiosis, as were CR images displayed on medical-grade computer monitors. The prevalence of small opacities (ILO category 1/0 or greater) did not differ between the two imaging modalities (5.2% for FSR and 4.8% for soft copy CR; p. 0.50). Inter-reader agreement was also similar between FSR and CR. Significant differences between image modalities were observed in the shape of small opacities, and in the proportion of miners demonstrating high opacity profusion (category 2/1 and above). Our results indicate that, with appropriate attention to image acquisition and soft copy display, CR digital radiography can be equivalent to FSR in the identification of small interstitial lung opacities.

  16. Development of computer-aided auto-ranging technique for a computed radiography system

    For a computed radiography system, the authors developed a computer-aided autoranging technique in which the clinically useful image data are automatically mapped to the available display range. The preread image data are inspected to determine the location of collimation. A histogram of the pixels inside the collimation is evaluated regarding characteristic values such as maxima and minima, and then the optimal density and contrast are derived for the display image. The effect of the autoranging technique was investigated at several hospitals in Japan. The average rate of films lost due to undesirable density or contrast was about 0.5%

  17. 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 that...... osteological ageing and sexing are more accurate when combining CT-images with excavated remains. Digital volume rendering further enables a compromised estimation of original cremation weight. Microexcavation is clearly a primary cause of bone fragmentation. Cremated remains affected by lower cremation...

  18. Neutron-computer tomography using real-time neutron radiography

    A real-time neutron radiography facility was constructed including the capability of neutron tomography. The neutron beam was measured for total neutron flux ((1.0 +/- 0.2) x 1011 m/(m2-sec)), gold cadmium ratio (52 +/- 3) and effective neutron temperature (830C +/- 80C). The angular divergence or nonparallelism of the neutron beam was measured to be 2.30 +/- 0.10 thereby providing a means of quantifying the collimator effectiveness. The resolution capabilities of both static film and real-time neutron radiographs were quantified using a Fourier transform algorithm to calculate the modulation transfer function of both types of radiographs. The contrast sensitivity of both types of radiographs. The contrast sensitivity of both types of radiographs was measured as 3.1% for film and 4.0% for real-time radiographs. Two tomography algorithms, the simultaneous iterative reconstruction technique (SIRT) and the convolution method, were programmed on an Intellect 100 Image Processing System. The SIRT algorithm was found to be too large and slow on the Intellect 100 to produce useful tomographs. The convolution method produced results near the theoretical resolution limits for a given number of projections. A tomographic resolution of at least 1.3 mm was demonstrated using 200 projections. Computer running time for the convolution method was found to be ∼ 30 seconds for each projection used. A series of experiments were conducted using the convolution method investigating the effect of high and low pass filtering, diagonal line enhancement and contrast stretching on the finished tomographs. These experiments showed that spatial resolution is not generally improved by these filtering functions but contrast sensitivity of the tomographs is improved

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

    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

  20. 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.

  1. Daily quality control in computed radiography mammography using the manufacturer phantom

    Jakubiak, Rosangela R.; Messias, Pricila C.; Oliveira, Carlla M., E-mail: requi@utfpr.edu.br [Technological Federal University of Parana (UTFPR), Curitiba, PR (Brazil). Academic Physics Dept.

    2011-07-01

    The quality control (QC) in mammography system involves a large amount of test tools, which implies a large space for storage and a high number of exposure. This work describes a QC system using a phantom, Fuji Computed Radiography (FCR) One Shot Phantom M Plus, that evaluates several parameters with just one exposure. The software offers tests with annual, semi-annual, quarterly, weekly and daily periodicity, and analyzes the conformities of the mammography equipment, image plate and cassettes. Because of the high number of tests, it was evaluated the daily test only for seven months in two mammography equipment. The test, through the software and its image, allows the analysis of ten parameters in QC. The evaluation of these parameters was realized by the average of the values provided by the software. Only one of the evaluated items showed not conformity, but this was observed and the necessary corrections were realized. The monitoring of use of FCR Mammography QC software with the FCR One Shot Phantom M Plus was realized and through this we could investigate that the quality program provided by the system is appropriate for the radiology services that has the Fuji Computed Radiography system. (author)

  2. A computer-aided diagnosis approach for emphysema recognition in chest radiography.

    Coppini, Giuseppe; Miniati, Massimo; Monti, Simonetta; Paterni, Marco; Favilla, Riccardo; Ferdeghini, Ezio Maria

    2013-01-01

    The purpose of this work is twofold: (i) to develop a CAD system for the assessment of emphysema by digital chest radiography and (ii) to test it against CT imaging. The system is based on the analysis of the shape of lung silhouette as imaged in standard chest examination. Postero-anterior and lateral views are processed to extract the contours of the lung fields automatically. Subsequently, the shape of lung silhouettes is described by polyline approximation and the computed feature-set processed by a neural network to estimate the probability of emphysema. Images of radiographic studies from 225 patients were collected and properly annotated to build an experimental dataset named EMPH. Each patient had undergone a standard two-views chest radiography and CT for diagnostic purposes. In addition, the images (247) from JSRT dataset were used to evaluate lung segmentation in postero-anterior view. System performances were assessed by: (i) analyzing the quality of the automatic segmentation of the lung silhouette against manual tracing and (ii) measuring the capabilities of emphysema recognition. As to step i, on JSRT dataset, we obtained overlap percentage (Ω) 92.7±3.3%, Dice Similarity Coefficient (DSC) 95.5±3.7% and average contour distance (ACD) 1.73±0.87 mm. On EMPH dataset we had Ω=93.1±2.9%, DSC=96.1±3.5% and ACD=1.62±0.92 mm, for the postero-anterior view, while we had Ω=94.5±4.6%, DSC=91.0±6.3% and ACD=2.22±0.86 mm, for the lateral view. As to step ii, accuracy of emphysema recognition was 95.4%, with sensitivity and specificity 94.5% and 96.1% respectively. According to experimental results our system allows reliable and inexpensive recognition of emphysema on digital chest radiography. PMID:22522287

  3. Ultrasonography in the diagnosis of nasal bone fractures: a comparison with conventional radiography and computed tomography.

    Lee, In Sook; Lee, Jung-Hoon; Woo, Chang-Ki; Kim, Hak Jin; Sol, Yu Li; Song, Jong Woon; Cho, Kyu-Sup

    2016-02-01

    The purpose of this study was to evaluate and compare the diagnostic efficacy of ultrasonography (US) with radiography and multi-detector computed tomography (CT) for the detection of nasal bone fractures. Forty-one patients with a nasal bone fracture who underwent prospective US examinations were included. Plain radiographs and CT images were obtained on the day of trauma. For US examinations, radiologist used a linear array transducer (L17-5 MHz) in 24 patients and hockey-stick probe (L15-7 MHz) in 17. The bony component of the nose was divided into three parts (right and left lateral nasal walls, and midline of nasal bone). Fracture detection by three modalities was subjected to analysis. Furthermore, findings made by each modality were compared with intraoperative findings. Nasal bone fractures were located in the right lateral wall (n = 28), midline of nasal bone (n = 31), or left lateral wall (n = 31). For right and left lateral nasal walls, CT had greater sensitivity and specificity than US or radiography, and better agreed with intraoperative findings. However, for midline fractures of nasal bone, US had higher specificity, positive predictive value, and negative predictive value than CT. Although two US evaluations showed good agreements at all three sites, US findings obtained by the hockey-stick probe showed closer agreement with intraoperative findings for both lateral nasal wall and midline of nasal bone. Although CT showed higher sensitivity and specificity than US or radiography, US found to be helpful for evaluating the midline of nasal bone. Furthermore, for US examinations of the nasal bone, a smaller probe and higher frequency may be required. PMID:25749616

  4. Computed tomography, ultrasonography and plain radiography in the detection of foreign bodies in pork muscle tissue

    To evaluate the possibility to detect foreign bodies in superficial soft tissue a comparative study including computed tomography, ultrasonography and plain radiography, is presented. Nine different materials, ranging in size from 2x3 to 3x10 mm, were inserted into pork muscle. All foreign bodies were detected and exact location was achieved using computed tomography and ultrasonography. In plain radiography wood was not visualised and exact location of all foreign bodies was not obtained. According to our results computed tomography and ultrasonography is useful in detecting foreign bodies in superficial soft tissue. (orig.)

  5. 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

  6. Computed radiography versus mobile direct radiography for bedside chest radiographs: Impact of dose on image quality and reader agreement

    Aim: To asses the image quality and potential for dose reduction of mobile direct detector (DR) chest radiography as compared with computed radiography (CR) for intensive care unit (ICU) chest radiographs (CXR). Methods and materials: Three groups of age-, weight- and disease-matched ICU patients (n = 114 patients; 50 CXR per acquisition technique) underwent clinically indicated bedside CXR obtained with either CR (single read-out powder plates) or mobile DR (GOS-TFT detectors) at identical or 50% reduced dose (DR50%). Delineation of anatomic structures and devices used for patient monitoring, overall image quality and disease were scored by four readers. In 12 patients pairs of follow-up CR and DR images were available, and in 15 patients pairs of CR and DR50% images were available. In these pairs the overall image quality was also compared side-by-side. Results: Delineation of anatomy in the mediastinum was scored better with DR or DR50% than with CR. Devices used for patient monitoring were seen best with DR, with DR50% being superior to CR. In the side-by-side comparison, the overall image quality of DR and DR50% was rated better than CR in 96% (46/48) and 87% (52/60), respectively. Inter-observer agreement for the assessment of pathology was fair for CR and DR50% (κ = 0.33 and κ = 0.39, respectively) and moderate for DR (κ = 0.48). Conclusion: Mobile DR units offer better image quality than CR for bedside chest radiography and allow for 50% dose reduction. Inter-observer agreement increases with image quality and is superior with DR, while DR50% and CR are comparable.

  7. 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

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

    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

  9. 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)

  10. 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...

  11. Neutron Radiography Analysis of a Transient Liquid Phase Joint

    Ballhausen, H.; Abele, H.; Eccleston, R. S.; Gaehler, R.; Smith, A. J.; A. Steuwer; Van Overberghe, A.

    2006-01-01

    Neutron radiography in many cases is the only non-destructive technique available for the analysis of a wide range of samples from metallurgy, materials engineering and materials testing. In this paper the potential of the technique is illustrated for a transient liquid phase (TLP) joint. TLP bonding produces interface free and stress free joints. The quality and properties of the joint depend on the diffusion of an interlayer into the base material. A TLP joint is visualised and the diffusio...

  12. Calculation and analysis of the neutron radiography spatial resolution

    Background: Spatial resolution is the key parameter for neutron radiography facility. A model of the integrated system resolution is important when designing or using a system to ensure that the realistic resolution goals can be established and achieved. Purpose: For this resolution modeling analysis we focused on the effects of the geometry effects of L/D, the optical diffusion response of the scintillator and the sampling at the sensor (CCD or CMOS camera) and a formula was derived indicating their functional relationship. Methods: This resolution modeling analysis has been down by theoretic calculations. Then this integrated system resolution model was used as an empirical methodology to verify and optimize the performance of the detection system for real-time neutron radiography at China Advance Research Reactor. Results: The special resolutions at very collimation conditions have been calculation by using this method. And three of important parameters of this resolution model have been discussed to optimize the system performance. Conclusion: These resolution analysis concepts and methods will benefit both the design and the characterization of radiography systems. (authors)

  13. The clinical application of computed radiography in bedside photography of newborn

    Objective: To evaluate the computed radiography in bedside photography of newborn, especially in chest radiography. Methods: Bedside CR images were selected in 100 cases randomly. The exposure parameters were optimized using the large latitude of CR. The details of images were post-processed and adjusted using spatial tuning technique. Then CR photography was compared with conventional X-ray photography. Results: The images acquired with CR had good contrast, high definition, and little distortion, in which the condemned image rate was 1%. While in conventional X-ray photography, the unsuccessful imaging rate is 9%. Conclusion: Bedside computed radiography of new-born, especially the chest imaging, is very helpful to improve image quality and positive rate of the diagnosis. (authors)

  14. Cholesteatoma: computed tomography and radiography in a dog

    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)

  15. Diagnostic value of computed tomography, radiography and ultrasonography in metacarpophalangeal joint disorders in horses

    V.M.V. Machado

    2016-02-01

    Full Text Available In modern society the work and athletic performance of horses has led to a very important animal production sector in which Brazil possesses the third largest horse stock. Among all equine lesions described, metacarpophalangeal (fetlock joint lesions are considered one of the main causes of lameness. Consequently, there is a need to improve the understanding and diagnosis of these injuries. The most efficient imaging diagnostic methods for the fetlock region are computed tomography, radiography and ultrasound. Imaging studies of the anatomical structures involving this joint are extremely important to obtain a more precise diagnose. The present study was performed in order to evaluate the capacity of different imaging diagnostic modalities to detect a variety of lesions in different fetlock structures. Twenty horses (Equus caballus used for horsemanship activities were referred to the Department of Animal Reproduction and Veterinary Radiology of São Paulo State University, Botucatu campus, with clinical signs of metacarpophalangeal joint injuries. Horses were submitted to radiographic and ultrasonographic exam and computed tomography scan. Image analysis revealed a significant capacity of these methods to characterize lesions in this region. However, computed tomography provided broader and better evaluation of lesions in bones and adjacent structures, because it allows the analysis to be performed on three-dimensional projections, with attenuation coefficients (window selections and tissue density measurement through Hounsfield Units (HU.

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

    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.

  17. 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.

  18. Lung cancer screening program using annual chest radiographs with computed radiography (FCR)

    Takashima, Tsutomu; Itoh, Hiroshi; Ikegaki, Shigeru; Chika, Koyata; Nitta, Haruo; Seno, Takashi; Miyashita, Yukichi; Kobayashi, Tadashi

    1987-08-01

    In the Wajima lung cancer screening program conducted under the auspices of Kanazawa University Hospital, Fuji Computed Radiography (FCR) was utilized in a new chest radiography trial. The results of the screening program are that the necessity of repeat examinations due to poor image quality are less common and the method enables detection of small pulmonary nodular shadows which are possibly candidates for surgery. Oblique chest X-ray with FCR is remarkably effective for the detection and the identification of small lesions. However, the disadvantage of slow processing and high cost must be fully satisfied if FCR is to become a new imaging modality for mass screening.

  19. Evaluation of diagnostic accuracy of conventional and digital periapical radiography, panoramic radiography, and cone-beam computed tomography in the assessment of alveolar bone loss

    Takeshita, Wilton Mitsunari; Vessoni Iwaki, Lilian Cristina; Da Silva, Mariliani Chicarelli; Tonin, Renata Hernandes

    2014-01-01

    Background: To evaluate the diagnostic accuracy of different radiographic methods in the assessment of proximal alveolar bone loss (ABL). Materials and Methods: ABL, the distance between cement-enamel junction and alveolar bone crest, was measured in 70 mandibular human teeth – directly on the mandibles (control), using conventional periapical radiography with film holders (Rinn XCP and Han-Shin), digital periapical radiography with complementary metal-oxide semiconductor sensor, conventional panoramic, and cone-beam computed tomography (CBCT). Three programs were used to measure ABL on the images: Image tool 3.0 (University of Texas Health Sciences Center, San Antonio, Texas, USA), Kodak Imaging 6.1 (Kodak Dental Imaging 6.1, Carestream Health®, Rochester, NY, USA), and i-CAT vision 1.6.20. Statistical analysis used ANOVA and Tukey's test at 5% significance level. Results: The tomographic images showed the highest means, whereas the lowest were found for periapical with Han-Shin. Controls differed from periapical with Han-Shin (P digital periapical (P = 0.0027). Conventional periapicals with film holders differed from each other (P = 0.0007). Digital periapical differed from conventional periapical with Han-Shin (P = 0.0004). Conclusions: Conventional periapical with Han-Shin film holder was the only method that differed from the controls. CBCT had the closest means to the controls. PMID:25191066

  20. Analyze image quality and comparative study between conventional and computed radiography applied to the inspection of alloys

    Piping system design takes into account relevant factors such as: internal coating, dimensioning, vibration system, adequate supports and principally, piping material. Cost is a decisive factor in the phase of material selection. The non-destructive testing method most commonly employed in industry to analyze the structure of an object is radiographic testing. Computed radiography (CR) is a quicker and much more efficient alternative to conventional radiography but, although CR presents numerous advantages, testing procedures are still largely based on trial and error, due to the lack of a consecrated methodology to choose parameters as it exists for conventional radiography. Notwithstanding, this paper presents a study that uses the technique of computed radiography to analyze metal alloys. These metal alloys are used as internal pipe coating aiming to protect against corrosion and cracks. This study seeks to evaluate parameters such as basic spatial resolution, Normalized Signal-to-Noise Ratio (SNRN), contrast, intensity and also to compare conventional radiography with CR. (author)

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

    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.

  2. 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.

  3. Radiography and bone scintigraphy in multiple myeloma: a comparative analysis

    The sensitivity of radionuclide imaging for detecting skeletal lesions was compared with that of radiography by evaluating 573 different anatomical sites in 41 patients with multiple myeloma. Radiography revealed a significantly greater number of myeloma-related bone lesions than did radionuclide imaging. Of the 179 myeloma-related bone lesions detected when both techniques were applied, 163 were seen by radiography and 82 by radionuclide imaging. Ninety-seven lesions were detected by radiography alone and 16 lesions seen by scintiscanning only, yielding a sensitivity of 91% for the former and of 46% for the latter technique. Radionuclide imaging proved superior to radiography only occasionally in the rib cage, and rarely in other anatomical sites. These findings suggest that radiography is the method of first choice in obtaining a skeletal survey in patients with multiple myeloma. In cases with continued pain, unexplained by standard radiography, the skeletal survey should be supplemented by tomography and radionuclide imaging. (author)

  4. Cone beam computed tomography and intraoral radiography for diagnosis of dental abnormalities in dogs and cats

    The development of veterinary dentistry has substantially improved the ability to diagnose canine and feline dental abnormalities. Consequently, examinations previously performed only on humans are now available for small animals, thus improving the diagnostic quality. This has increased the need for technical qualification of veterinary professionals and increased technological investments. This study evaluated the use of cone beam computed tomography and intraoral radiography as complementary exams for diagnosing dental abnormalities in dogs and cats. Cone beam computed tomography was provided faster image acquisition with high image quality, was associated with low ionizing radiation levels, enabled image editing, and reduced the exam duration. Our results showed that radiography was an effective method for dental radiographic examination with low cost and fast execution times, and can be performed during surgical procedures

  5. Quantitative assessment of the impact of computed radiography and PACS on imaging service delivery

    The San Francisco Veterans Administration Medical Center is a pilot center for computed radiography and picture archiving and communications system (PACS). The impact of PACS on health care is unclear because of a lack of rigorous pre- and postimplementation studies. In this paper the authors describe a simple audit method to determine patient waiting time, imaging time, film use, the availability of images to radiologists and clinicians, prior image retrieval, and time to final interpretation. A preimplementation audit showed some lone waiting times (up to 40 minutes; average, 20 minutes), and only 42% immediate retrieval of prior films (average retrieval time, 22 hours). Computed radiography an PACS have the potential to improve these figures

  6. Quantitative Performance Assessment of Computed Radiography for Corrosion Detection in Process Pipes

    Venkatachalam, Rajashekar; Raghu, C.; Pandey, Pramod; Vedula, Venumadhav; Thapa, Prasad; Venugopal, Manoharan

    2007-03-01

    Evaluation of integrity of process pipes in service is an important preventive maintenance issue for power generation and petrochemical industries. Ultrasonic wall thickness is traditionally used to measure wall thickness loss due to corrosion. This technique has various limitations such as need for removal of insulation, point based measurements and unsuitability for high temperature applications. Many have attempted computed radiography to quantify corrosion in pipelines as an alternative technique. Computed Radiography can be carried out without removing insulation and also at higher temperatures. However, the minimum detectability limit of wall thickness loss is limited by various physics complications in radiographic imaging process i.e. scattering, modulation due to detector response, focal spot blurring, the effective thickness of insulation and fluid inside pipe. An attempt has been made to study the effect of insulation and fluid inside pipe on detectability of wall loss due to corrosion using physics simulations and experiments.

  7. Automatic measurement system for congenital hip dislocation using a computed radiography

    Acetabular angle which is a diagnostic parameter of congenital hip dislocation has been measured manually in conventional X-ray film system. Using digital image directly provided from a computed radiography, an automatic measurement system was developed for this parameter. The process of the measurement was completed within a reasonable time, and accurate enough. The system was combined with an image database, so that it would be a measurement tool of PACS

  8. Real-time measurement and audit of radiation dose to patients undergoing computed radiography.

    Vano, Eliseo; Fernandez, Jose Miguel; Ten, Jose Ignacio; Guibelalde, Eduardo; Gonzalez, Luciano; Pedrosa, Cesar S A

    2002-10-01

    A real-time patient dose monitoring system for auditing computed radiography is described. Technical data from each exposure and for every examination type are collected and sent by a network to a workstation, which calculates the moving average values of entrance skin dose and dose-area product from the 10 most recently examined patients. Comparison of averages with reference values generates warning messages if reference values are exceeded, prompting corrective action if necessary. PMID:12355017

  9. Development of a kinetic analysis technique for PACS management and a screening examination in dynamic radiography

    The purpose of this study was to develop a method of kinetic analysis for picture archiving and communication system (PACS) management and computer-aided diagnostic application in dynamic chest radiography. The main analytical technique used in this study was a new algorithm that converts dynamic radiographs into a color-static image. The algorithm is a visualization technique for kinetic information that uses the intensity-density transformation and the direction classification in optical flow. The image made by the new algorithm was defined as a 'kinetic map', and, by analysis using the kinetic map, a patient collation system and nodule detection system were constructed. By analysis that used an artificial neural network of certain feature vectors as kinetic map similarity, the collation system obtained good identification performance. Temporal subtraction processing between a current-status map with simulated nodule and previous-status map detected the region of abnormality as the simulated nodule. It is expected that our method of analysis will be useful as a screening examination for risk management and computer-aided diagnostic application in dynamic chest radiography. (author)

  10. Risk analysis of radiography as a nondestructive testing method

    The risk analysis was made in preparation of a safety manual for the wide variety of applications of industrial radiography. The safety manual is intended to serve as a guide to professionals, presenting the information about safety and health risks involved in a concise though very illustrative manner. The potential risks were listed and evaluated on the occasion of a meeting of experts in October 1999, who used the FMEA analysis, a quality management tool. The following methods or sources were analysed and rated in terms of risks involved: (a) ionizing radiation (b) electric power (c) handling of radioactive radiation sources (d) minor accidents (e) defect equipment (f) activities at construction sites (g) transportation of gear and instruments (h) auxiliary equipment. The risk evaluation presented in the paper also permits identification of problematic aspects in the daily routine. (orig./CB)

  11. Lung nodule conspicuity using unsharp mask filters with storage-phosphor-based computed radiography

    Purpose: To compare the performance of various types of unsharp mask filter applied in storage-phosphor-based computed radiography (SR), and to improve the detection of faint nodules of the lung cancer type. Material and Methods: A total of 120 SR radiographs were obtained by means of an anthropomorphous chest phantom and a combination of 3 types of small simulated nodule (5-mm sphere-shaped, and 5-mm and 10-mm hemisphere-shaped) placed on the phantom's surface. Eight combinations of nodule site were selected from 16 predetermined chosen sites, and 5 types of parameter were used for unsharp mask filtering. Eight observers evaluated the images, and the detectability of the lung nodules was evaluated from the images by a ROC analysis. Results: The visibility of the 10-mm hemispherical nodules was nearly equivalent at each site when 5 types of unsharp mask filter were used. The detection of the 5-mm nodules with mid-frequency suppressing and very-low-frequency enhancing filters was better than with a conventional (department standard) mid-frequency enhancing filter. Conclusion: Mid-frequency suppressing versions of the filter helped to demonstrate faint nodular opacity, which is often shown by early bronchogenic carcinoma. This filter could replace conventional filters in the detection of lung nodules. (orig.)

  12. A comparison of cathode ray tube (CRT) and computed radiography (CR) diagnosis in mammography

    Kinoshita, Takahiro; Odagiri, Kunio; Andoh, Kazuo; Doiuchi, Tunehiro; Seno, Kengo; Ohtsuka, Toshihiro [Kanagawa Cancer Center, Yokohama (Japan); Matsumoto, Toru

    1999-11-01

    Quantitative evaluation of CRT and CR observations in indentification of malignancy using phantom and clinical data. A breast phantom and a total of 40 patients were imaged by Fuji computed radiography (FCR). The images were interpreted twice by six radiologists both on CR film (2510 x 2000 pixels x 10 bits, 0.1 mm spatial resolution) and on a CRT monitor (1568 x 1152 pixels x 10 bits, 0.1 mm pixel size with double expansion) with image processing parameters of a toutine (RN 1.0, RE 0.2), for a calcification (RN 9.0, RE 4.0) and for a mass (RN 7.0, RE 2.0). The forty clinical cases included breast diseases with calcifications, masses, and normal breasts. Two-tailed t-test was performed to analyze interpretation of simulated microcalcifications and masses in the phantom. The receiver operating characteristic (ROC) analysis was performed to evaluate clinical cases. In all interpretation studies using both breast phantom and clinical cases, there was no significant difference between the two interpretation methods. However the CRT diagnosis was slightly less accurate than CR film diagnosis due to the lower luminance levels of the CRT monitor. Diagnosis via CRT monitor may be substituted for CR film diagnosing breast abnormalities, but the image processing parameters of CRT require improvement to compensate for low luminance. (author)

  13. 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

  14. Dose area product measurement for diagnostic reference levels and analysis of patient dose in dental radiography

    In this study, diagnostic reference levels (DRLs) were suggested and patient doses were analysed through the dose-area product value in dental radiography. In intraoral radiography, at three sites, i.e. molar, premolar and incisor on the maxilla and acquired third quartile values: 55.5, 46 and 36.5 mGy cm2, respectively, were measured. In panoramic, cephalo-metric and cone beam computed tomography, the values were 120.3, 146 and 3203 mGy cm2 (16 x 18 cm), respectively. It has been shown that, in intraoral radiography, the patient dose changes proportionally to the value of mA s, but the change in extra-oral radiography in response to mA s could not be confirmed. The authors could confirm, however, the difference in dose according to the manufacturer in all dental radiography examinations, except for panoramic radiography. Depending on the size of hospital, there were some differences in patient dose in intraoral radiography, but no difference in patient dose in extra-oral radiography. (authors)

  15. 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...... 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...... 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...

  16. Comparison of periapical radiography with cone beam computed tomography in the diagnosis of vertical root fractures in teeth with metallic post

    Wilton Mitsunari Takeshita

    2014-01-01

    Full Text Available Aim: To compare the diagnostic accuracy of conventional periapical radiography and cone beam computed tomography (CBCT in detecting vertical root fracture (VRF in tooth with metallic post (MP. Materials and Methods: Twenty endodontically-treated teeth received MPs, artificial fractures were created in 10 teeth, and they were all examined with tomography and radiography. The sample consisted of periapical radiography with post and without post, and tomography with post and without post; each group with five fractured and five non-fractured teeth. The images were evaluated by three dental/maxillofacial radiologists and statistical validations were carried out using receiver operating characteristic (ROC analysis. Results: Sensitivity and specificity of the area under the ROC (Az of tomography with post (Az = 0.953 and without post (Az = 0.956 were significantly higher than those of periapical radiography with post (Az = 0.753 and without post (Az = 0.778. Conclusion: CBCT was more accurate than conventional periapical radiography in detecting VRF.

  17. Cephalometric radiography and computed tomography in infants undergoing craniofacial surgery

    Craniofacial growth after surgery in children is not completely understood. We have therefore formed a programme for pre- and postoperative studies with both roentgencephalometric- and computed tomographic investigations. This regiment results in overlapping information. Thus, an assessment of the advantages and disadvantages of the two methods was made and exemplified in four patients. In our experience both cephalometry and CT are essential for the diagnosis, surgical planning and follow-up of surgically treated children with craniofacial anomalies. To minimize the radiation doses and the diagnostic procedures which in these cases often includes general anesthesia, patients with isolated, asymmetrical conditions such as plagiocephaly, might be followed with CT only, since roentgencephalometry can not add much information. (Authors)

  18. Corrosion monitoring with tangential radiography and limited view computed tomography

    Ewert, Uwe; Tschaikner, Martin; Hohendorf, Stefan; Bellon, Carsten; Haith, Misty I.; Huthwaite, Peter; Lowe, Michael J. S.

    2016-02-01

    Accurate and reliable detection of subsea pipeline corrosion is required in order to verify the integrity of the pipeline. A laboratory trial was conducted with a representative pipe sample. The accurate measurement of the wall thickness and corrosion was performed with high energy X-rays and a digital detector array. A 7.5 MV betatron was used to penetrate a stepped pipe and a welded test pipe of 3 m length and 327 mm outer diameter, with different artificial corrosion areas in the 24 mm thick steel wall. The radiographs were taken with a 40 x 40 cm² digital detector array, which was not large enough to cover the complete pipe diameter after magnification. A C-arm based geometry was tested to evaluate the potential for automated inspection in field. The primary goal was the accurate measurement of wall thickness conforming to the standard. The same geometry was used to explore the ability of a C-arm based scanner in asymmetric mode for computed tomography (CT) measurement, taking projections covering only two thirds of the pipe diameter. The technique was optimized with the modelling software aRTist. A full volume of the pipe was reconstructed and the CT data set was used for reverse engineering, providing a CAD file for further aRTist simulations to explore the technique for subsea inspections.

  19. Studies on image quality optimisation in computed radiography for weld inspection

    The application of metal filters and metal screens improves the image contrast in film radiography. The mechanism of latent X-ray image generation and, its read-out from imaging plates and the subsequent visualization is different from that of radiographic films. The use of metal screens and the selection of the X ray tube voltage as recommended in the film radiography standards are not transferable for Computed Radiography (CR) for weld inspection. The quality of digital radiographs is determined by the inherent unsharpness and the Contrast to Noise Ratio (CNR). Whereas the standard EN 14784-1 describes manageable procedures for the determination of inherent unsharpness and Signal to Noise Ratio (SNR), the rules for the improvement of contrast by selection of the suitable tube voltage and metal screen thickness were not described sufficiently in EN 14874-2. Systematic studies on the influence of copper filter, lead screen imaging plate combinations as well as X-ray tube voltage on the image contrast were performed to improve the image quality for testing of welds with CR systems. Recommendations for the application of metal filter and screen combinations and the selection of appropriate X-ray tube voltages for the imaging plate technique were deduced from these results in order to optimise the X-ray testing procedure of welds. (orig.)

  20. Conception of man in diagnostic radiography research – A discourse analysis of research articles from the journal radiography

    Aim: To analyse discourses of conceptions of man in scientific texts of diagnostic radiography and how these conceptions are constructed in texts. Background: In this article conception of man refers to assumptions researchers have when selecting targets for research, choosing methods and making hypotheses. Method: A discourse analysis is being applied in this article to find discourses in scientific texts on diagnostic radiography. The material consisted of 45 articles from the journal Radiography from February 2009 to August 2013. Findings: Four main discourses were found. They were named technology-centred, patient-centred, doubtful patient and invisible patient discourses. In the technology-centred discourse patients were usually seen as an anonymous group, and they were passive. In the patient-centred discourse patient experiences were often sought and researchers tried to understand patients' emotions, physical abilities and social context. Patients were seen as individuals and active agents. In the doubtful patient discourse patients are not always trusted. In this discourse health care professionals often know better what is for the good of the patient. In the invisible patient discourse patients are invisible to the radiographer/researcher. They are seen merely as body parts, symptoms or diseases

  1. Digital Radiography Reject Analysis: Data Collection Methodology, Results, and Recommendations from an In-depth Investigation at Two Hospitals

    Foos, David H.; Sehnert, W. James; Reiner, Bruce; Siegel, Eliot L.; Segal, Arthur; Waldman, David L.

    2008-01-01

    Reject analysis was performed on 288,000 computed radiography (CR) image records collected from a university hospital (UH) and a large community hospital (CH). Each record contains image information, such as body part and view position, exposure level, technologist identifier, and—if the image was rejected—the reason for rejection. Extensive database filtering was required to ensure the integrity of the reject-rate calculations. The reject rate for CR across all departments and across all exa...

  2. Digital radiography.

    Mattoon, J S

    2006-01-01

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

  3. Dose audit for radiation safety during intravenous urography procedures using computed radiography imaging system

    Dose auditing was done during intravenous urography (IVU) procedure. Eighty patients undergoing IVU examination were included in this study. All investigations were made using a conventional x-ray machine equipped with linear tomography device and images were processed in a Computed Radiography (CR) reader interfaced to a Picture Archival and Communication System (PACS). Thermoluminescent dosimeter was made use of in measurement of radiation dose imparted to patients during IVU procedures. An average of 9.4 radiographs were taken for each IVU procedure and the average effective dose ranged from 0.28 mSv to 7.52 mSv. (author)

  4. Use of computed radiography in respiratory distress syndrome in the neonatal nursery

    A study was performed to establish the value of a computed radiography (CR) system in neonatal respiratory distress syndrome (RDS). CR images obtained with various X-ray doses were compared with the images of a standard film-screen system. The image quality of CR taken with about one half radiation exposure, was comparable to that of the standard high speed film-screen combination. The use of CR could lead to a significant reduction in radiation in the neonatal I.C.U. (orig.)

  5. The use of computed radiography plates to determine light and radiation field coincidence

    Purpose: Photo-stimulable phosphor computed radiography (CR) has characteristics that allow the output to be manipulated by both radiation and optical light. The authors have developed a method that uses these characteristics to carry out radiation field and light field coincidence quality assurance on linear accelerators.Methods: CR detectors from Kodak were used outside their cassettes to measure both radiation and light field edges from a Varian linear accelerator. The CR detector was first exposed to a radiation field and then to a slightly smaller light field. The light impinged on the detector's latent image, removing to an extent the portion exposed to the light field. The detector was then digitally scanned. A MATLAB-based algorithm was developed to automatically analyze the images and determine the edges of the light and radiation fields, the vector between the field centers, and the crosshair center. Radiographic film was also used as a control to confirm the radiation field size.Results: Analysis showed a high degree of repeatability with the proposed method. Results between the proposed method and radiographic film showed excellent agreement of the radiation field. The effect of varying monitor units and light exposure time was tested and found to be very small. Radiation and light field sizes were determined with an uncertainty of less than 1 mm, and light and crosshair centers were determined within 0.1 mm.Conclusions: A new method was developed to digitally determine the radiation and light field size using CR photo-stimulable phosphor plates. The method is quick and reproducible, allowing for the streamlined and robust assessment of light and radiation field coincidence, with no observer interpretation needed

  6. Evaluation of image quality and radiation dose in mammography: a comparison among digital radiography, computed radiography and film-screen systems

    Objective: To compare the image quality, radiation dose and diagnostic accuracy on film-screen, digital radiography (DR) and computed radiography (CR) mammography. Methods: Three different kinds of mammography machines (film-screen, DR and CR) were tested to make sure they were qualified and comparable. Radiographs were taken on Mammo-152 phantom and ACR phantom using film- screen, DR and CR systems with the same radiation dose. Next, radiographs were taken on two phantoms using DR and CR systems with classic mode or AEC and the radiation dose was recorded. The images were numbered and scored by eight independent experienced radiologists under the same reading condition according to ACR method. Statistics was performed with the randomized complete-block design variance analysis. The diagnostic accuracy of three kinds of mammography methods were compared with Kappa test in clinical cases who had pathologic results. Results: The spatial resolution of film-screen system was the highest (7.0-8.0 Lp/mm) and that of CR was the lowest (2.5 Lp/mm). When the radiation dose was increased (27.0%-30.0%), the resolution was improved with DR (+11.0%) but almost no change with CR (+1.5%). The radiation dose of DR was the lowest on ACR phantom. The delineation of mass was better on film-screen than on CR, but the delineation of fibers and speck was better on CR. When the radiation dose of CR was increased (25.0%), the delineation of fibers and speck on CR was similar to that on DR and the delineation of mass was similar to that on film-screen. There was a good correlation between the mammography diagnosis and pathological results (film-screen is 50/56, DR is 83/90 and CR is 61/69, P0.75). The diagnostic accuracy of three mammography systems had no statistical difference [film-screen 89.3% (50/56), DR 92.2% (83/90) and CR 88.4% (61/69 ), Pearson χ2=0.722, P=0.697]. Conclusion: Film/screen system has the highest space resolution and DR has the lowest radiation dose. Three

  7. 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.

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

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

  9. The application of the Fuji Computed Radiography system for the diagnosis of pneumoconiosis

    A computer controlled digital system, Fuji Computed Radiography (FCR) is capable of providing more stable output image than conventional screen/film system. So FCR would be an ideal system for the detection of pneumoconiosis due to the constant high quality of the output films. We tried to find the optimum image processing to compensate the small size (1/2 in length of a full-size radiograph) of the output image of digital radiography. The best result for FCR was given with gamma 0.85 and 0.30 enhancement of response at spatial frequency of 0.085 cycle/mm. On the other hand, the digitally processed FCR size ILO standard films, the characteristics of which is different from FCR output films, proved to be most preferable when the image processing is made with gamma 0.85 and 0.25 enhancement at spacial frequency of 0.17 cycle/mm. If the above mentioned image processings are adopted, FCR can be used for the diagnosis of pneumoconiosis with the same accuracy as the conventional film method. (author)

  10. Development of a computer simulation system of intraoral radiography using perspective volume rendering of CT data

    The purpose of this study was to evaluate the usefulness of a computer simulation system for intraoral radiography as an educational aid for radiographic training for dental students. A dried skull was scanned with a multidetector CT, and the series of slice data was transferred to a workstation. A software AVS Express Developer was used to construct the x-ray projected images from the CT slice data. Geometrical reproducibilities were confirmed using numerical phantoms. We simulated images using the perspective projection method with an average value algorithm on this software. Simulated images were compared with conventional film images projected from the same geometrical positions, including eccentric projection. Furthermore, to confirm the changes of the image depending on the projection angles of the x-ray beam, we constructed simulation images in which the root apexes were enhanced with the maximum value algorithm. Using this method, high resolution simulated images with perspective projection, as opposed to parallel, were constructed. Comparing with conventional film images, all major anatomic components could be visualized easily. Any intraoral radiographs at an arbitrary angular projection could be simulated, which was impossible in the conventional training schema for radiographic technique. Therefore, not only standard projected images but also eccentric projections could be displayed. A computer simulation system of intraoral radiography with this method may be useful for training in intraoral radiographic technique for dental students. (author)

  11. Computed radiography as a gamma ray detector—dose response and applications

    O'Keeffe, D. S.; McLeod, R. W.

    2004-08-01

    Computed radiography (CR) can be used for imaging the spatial distribution of photon emissions from radionuclides. Its wide dynamic range and good response to medium energy gamma rays reduces the need for long exposure times. Measurements of small doses can be performed without having to pre-sensitize the computed radiography plates via an x-ray exposure, as required with screen-film systems. Cassette-based Agfa MD30 and Kodak GP25 CR plates were used in applications involving the detection of gamma ray emissions from technetium-99m and iodine-131. Cassette entrance doses as small as 1 µGy (140 keV gamma rays) produce noisy images, but the images are suitable for applications such as the detection of breaks in radiation protection barriers. A consequence of the gamma ray sensitivity of CR plates is the possibility that some nuclear medicine patients may fog their x-rays if the x-ray is taken soon after their radiopharmaceutical injection. The investigation showed that such fogging is likely to be diffuse.

  12. 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.

  13. Comparative study of mesothelioma and asbestosis using computed tomography and conventional chest radiography

    A comparative study using computed tomography and conventional posteroanterior radiography was performed on 27 patients with mesothelioma and 13 patients with advanced asbestosis. The major pathologic features of both asbestosis and mesothelioma were well demonstrated by both modalities; computed tomography demonstrated the findings more frequently and in greater detail. No distinguishing features could be established based on configuration and size of the lesion. Many pleural plaques associated with advanced asbestosis were large and irregular and resembled those associated with mesothelioma. However, nodular involvement of the pleural fissures, pleural effusion, and ipsilateral volume loss with a fixed mediastinum were features predominating in mesothelioma. Growth determination of the plaques associated with asbestosis may be of minimal value since such plaques also undergo growth due to active inflammatory changes

  14. 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. PMID:23986937

  15. Digital vs conventional radiography: cost and revenue analysis

    The objective of this study was to analyse and compare the operating and investment costs of two radiographic systems, a conventional and a digital one, and to evaluate the cost/revenue ratio of the two systems. The radiological activity over 1 year for chest and skeletal exams was evaluated: 13,401 chest and 7,124 skeletal exams were considered. The following parameters of variable costs were evaluated: the difference between variable proportional costs of the two technologies, the effective variable cost of any size film, including the chemicals, and for different sizes of digital film, variable costs of chest plus skeletal exams performed with the two techniques. Afterwards the economical effect was considered taking into account depreciation during a time of utilization ranging between 8 and 4 years. In the second part of the analysis the total cost and the revenues of the two technologies were determined. The comparison between the digital and conventional systems has shown the following aspects: 1. Digital radiography system has a much higher investment cost in comparison with the conventional one. 2. Operating costs of digital equipment are higher or lower depending on the film size used. Evaluating chest X-ray we reach a breakeven point after 1 year and 10,000 exams only if displayed over 8 x 10-in. film and after 30,000 if displayed over a 11 x 14-in. film. 3. The total cost (variable cost, technology cost, labour cost) of digital technology is lower than that of the conventional system by 20 % on average using 8 x 10-in. film size. 4. Digital technology also allows lesser film waste and lesser film per exam (orig.)

  16. Dose reduction using non lineal diffusion and smoothing filters in computed radiography

    The use of Computed Radiography (CR) into clinical practice has been followed by a high increase in the number of examinations performed and overdose cases in patients, especially children in pediatric applications. Computed radiographic images are corrupted by noise because either data acquisition or data transmission. The level of this inherent noise is related with the X-ray dose exposure: lower radiation exposure involves higher noise level. The main aim of this work is to reduce the noise present in a low radiation dose CR image in order to the get a CR image of the same quality as a higher radiation exposure image. In this work, we use a non lineal diffusion filtering method to reduce the noise level in a CR, this means that we are able to reduce the exposure, milliampere-second (mAs), and the dose absorbed by the patients. In order to get an optimal result, the diffusive filter is complemented with a smoothing filter with edge detection in order to preserve edges. Therefore, the proposed method consists in obtaining a good quality CR image for diagnostic purposes by selection of lower X-ray exposure jointly with a reduction of the noise. We conclude that a good solution to minimize the dose to patients, especially children in pediatric applications, in X-ray computed radiography consists in decreasing the mAs of the X-ray exposure and then processing the image with the proposed method. - Highlights: • We have investigated the techniques to obtain the image quality to make a confident diagnosis. • We have used diffusion and smoothing filter in order to reduce the exposure. • Reducing CR doses, especially in pediatric applications. • The new CR images allow medical researchers to analyze how low dose affects the patient diagnosis

  17. 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...... measuring volumes of erosions on CT and MRI is reproducible and correlated to semiquantitative assessments (scores) of erosions on CT, MRI and radiography. METHODS: Seventeen patients with rheumatoid arthritis and four healthy control individuals underwent CT, MRI and radiography of one wrist, performed 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 of...

  18. Analysis of the potential of crack detection by neutron radiography

    The principle is explained of nondestructive crack detection using neutrons. A survey is presented of sources, principles of moderation and collimation; the interaction is explained of neutrons with matter and methods of detection. The method of neutron radiography is used for inspecting fuel in nuclear power plants, for the detection of corrosion and water in aviation, crack detection of special alloys, in the chemical industry, engineering, testing of printed circuits in electronics, dosemeter calibration, etc. (M.D.). 2 figs, 1 tab

  19. Initial quality performance results using a phantom to simulate chest computed radiography

    Muhogora Wilbroad

    2011-01-01

    Full Text Available The aim of this study was to develop a homemade phantom for quantitative quality control in chest computed radiography (CR. The phantom was constructed from copper, aluminium, and polymenthylmethacrylate (PMMA plates as well as Styrofoam materials. Depending on combinations, the literature suggests that these materials can simulate the attenuation and scattering characteristics of lung, heart, and mediastinum. The lung, heart, and mediastinum regions were simulated by 10 mm x 10 mm x 0.5 mm, 10 mm x 10 mm x 0.5 mm and 10 mm x 10 mm x 1 mm copper plates, respectively. A test object of 100 mm x 100 mm and 0.2 mm thick copper was positioned to each region for CNR measurements. The phantom was exposed to x-rays generated by different tube potentials that covered settings in clinical use: 110-120 kVp (HVL=4.26-4.66 mm Al at a source image distance (SID of 180 cm. An approach similar to the recommended method in digital mammography was applied to determine the CNR values of phantom images produced by a Kodak CR 850A system with post-processing turned off. Subjective contrast-detail studies were also carried out by using images of Leeds TOR CDR test object acquired under similar exposure conditions as during CNR measurements. For clinical kVp conditions relevant to chest radiography, the CNR was highest over 90-100 kVp range. The CNR data correlated with the results of contrast detail observations. The values of clinical tube potentials at which CNR is the highest are regarded to be optimal kVp settings. The simplicity in phantom construction can offer easy implementation of related quality control program.

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

    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. (paper)

  1. 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.

  2. Comparison of diagnostic accuracy of root perforation, external resorption and fractures using cone-beam computed tomography, panoramic radiography and conventional & digital periapical radiography

    Wilton Mitsunari Takeshita

    2015-01-01

    Conclusions: CBCT showed the best results in the diagnosis of ERR and VRF. The diagnosis of ERR was the least accurate, panoramic radiography being not appropriate for its diagnosis. CBCT and conventional periapical radiography obtained similar results for the evaluation of RP. So for, RP indicate the conventional periapical radiography because CBCT has a higher radiation dose.

  3. The effect of radiation dose reduction on clinical image quality in chest radiography of premature neonates using a dual-side readout technique computed radiography system

    The purpose of the present study was to investigate if the exposure could be reduced from the clinical setting (resulting in an effective dose of 8 μSv for a neonate of weight 0.7 kg and height 25 cm at a tube voltage of 90 kV) without negatively influencing the image quality for a dual-side readout technique computed radiography (CR) system in chest radiography of premature neonates. Chest radiographs of premature neonates were acquired with the double-side readout technique CR system. The images underwent simulated dose reduction in steps of 20% to represent five different radiation dose levels. Four image quality criteria, related to the visibility of important anatomical structures, were used in a visual grading study where five experienced radiologists rated how well the criteria were fulfilled for all images. When reducing the radiation dose, a decrease in image quality could be observed already at the 80% dose level for all the structures. The results indicate that a decrease in exposure from the clinically used setting affects the image quality negatively for the CR system. (authors)

  4. Combined photon-neutron radiography for nondestructive analysis of materials

    Combined photon-neutron radiography was investigated as a nondestructive method to determine the shape and material composition of complex objects. A system consisting of photon and neutron sources in a cone beam configuration and a 2D detector array was modeled using the MCNP5 code. Photon-to-neutron transmission ratios were determined for a car engine using 0.1, 0.5, 2.5 MeV neutrons and 0.2, 0.5, 1 MeV photons. Focusing on inherent difference between neutron and photon interactions with matter, it was possible to classify materials within the scanned object. (author)

  5. Development of automatic analyses for star-shot images using computed radiography (CR)

    Recent progress in radiation therapy has been greatly enhanced in many facilities by the development of new machines for treatment, improved computer technology for radiotherapy treatment planning systems (RTPs), increased accuracy of radiation therapy such as stereotactic irradiation, and intensity-modulated radiation therapy (IMRT). Quality control (QC) of the isocenter, which has consisted of gantry rotation and limiting the radiation field, is important for greater accuracy of these radiation therapy technologies. Star-shot analyses using computed radiography (CR) for evaluation of the isocenter were employed in this study. Devices to support CR were created, and a method of automatically analyzing images obtained by the star-shot technique, which calculated the error (distance) from the isocenter and the incident beam angle, were developed. In terms of the accuracy of our method, the average maximum error was 0.33 mm (less than 2 pixels: 0.35 mm), the average absolute error and incident beam angle errors were 0.3 mm and 0.4 degrees at maximum and at one standard deviation (SD), respectively. In this study, the processing times were 16 sec at minimum, 152 sec at maximum, 18 sec at most frequencies, and 23.6 sec on average. In conclusion, it was considered that our newly developed method for analyzing star-shot images using CR enabled immediate, quantitative evaluation of the isocenter. (author)

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

    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)

  7. 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)

  8. Radiography - A new field among health sciences in Finland

    In order to secure high quality X-ray services and efficient operation of clinical radiography, a study programme in radiography science was implemented at the University of Oulu in 1999. The need for a specific field of science has emerged as a result of social changes, such as the aging population, and the fast development of technology that has caused significant changes in the radiological working environment and clinical radiography. A need for a new, research-based informational foundation of clinical radiography is the basis for the programme. As service producers, radiographers need vast knowledge as well as specific expertise. The research object of radiography science is clinical radiography. If it was studied from the viewpoint of other sciences, the key professional skills of a radiographer would remain unexplored. Implementing an own field of science has enabled the development of radiography from its own bases. Basic research in the field is represented, for example, by the concept analysis of radiography in health sciences. Radiography science should produce research results for both clinical radiography and the instruction of radiography. So far, research results have dealt with the professional decision-making of a radiographer, the influences of computer technology on a radiographer's work and measuring the radiation exposure of a population

  9. 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.)

  10. Analysis of physeal growth in dogs, using biplanar radiography

    Biplanar radiography was used to study normal growth of the left and right radius in 5 Beagles and growth of the left radius alone in 15 additional Beagles. We explored the applicability of this radiographic method in veterinary medicine by measuring the contribution to total radius length from each growth plate. Spherical tantalum markers (0.5 mm) were embedded in the proximal epiphysis, diaphysis, and distal epiphysis of each dog's radius at 10 weeks of age. Simultaneous biplanar radiographic views were obtained every 4 weeks until skeletal maturity was documented. A three-dimensional coordinate system was constructed allowing for measurement of growth (in millimeters). Resolution of the measuring system was 0.074 mm. Mean +/- SEM length of the skeletally mature Beagle's radius, as measured from proximal epiphyseal bead to distal epiphyseal bead, was 95.33 +/- 1.07 mm. The percentage of contribution to the total radius length from the proximal and distal growth plates was 36.76 and 64.73%, respectively, with 95% confidence interval of 2.29%. The percentage of contribution to radius length from the distal radial growth plate increased for each consecutive time segment, with the distal radial physis contributing 61.75% from 10 to 14 weeks of age and increasing to 70.22% from 22 to 26 weeks of age. Significant growth was not observed after 26 weeks of age. The period of most rapid growth was between 10 and 14 weeks of age. Biplanar radiography was accurate and precise in quantifying the relative contribution of the proximal and distal growth plate to radius length in Beagles. The method is applicable in veterinary research or clinical medicine for monitoring of axial and angular growth: physiologic, iatrogenic, or pathologic

  11. Patient dose, gray level and exposure index with a computed radiography system

    Silva, T. R.; Yoshimura, E. M.

    2014-02-01

    Computed radiography (CR) is gradually replacing conventional screen-film system in Brazil. To assess image quality, manufactures provide the calculation of an exposure index through the acquisition software of the CR system. The objective of this study is to verify if the CR image can be used as an evaluator of patient absorbed dose too, through a relationship between the entrance skin dose and the exposure index or the gray level values obtained in the image. The CR system used for this study (Agfa model 30-X with NX acquisition software) calculates an exposure index called Log of the Median (lgM), related to the absorbed dose to the IP. The lgM value depends on the average gray level (called Scan Average Level (SAL)) of the segmented pixel value histogram of the whole image. A Rando male phantom was used to simulate a human body (chest and head), and was irradiated with an X-ray equipment, using usual radiologic techniques for chest exams. Thermoluminescent dosimeters (LiF, TLD100) were used to evaluate entrance skin dose and exit dose. The results showed a logarithm relation between entrance dose and SAL in the image center, regardless of the beam filtration. The exposure index varies linearly with the entrance dose, but the angular coefficient is beam quality dependent. We conclude that, with an adequate calibration, the CR system can be used to evaluate the patient absorbed dose.

  12. Evaluation of entrance surface air kerma from exposure index in computed radiography

    Costa, A. M.; Pelegrino, M. S.

    2014-11-01

    The aim of this study was to establish an indirect method to calculate the values of entrance surface air kerma in patients undergoing diagnostic examinations in X-ray systems with computed radiography based on the exposure index. The entrance surface air kerma values were compared with values obtained also indirectly based on measurements of X-ray tube output. The mean±standard deviation (1σ) and third quartile for entrance surface air kerma calculated from the exposure index were 2.1±1.0 mGy and 3.0 mGy, respectively. For entrance surface air kerma based on measurements of the X-ray tube output, the mean±standard deviation (1σ) and third quartile were respectively 3.1±1.9 mGy and 5.5 mGy. The observed values of entrance surface air kerma are smaller than the reference level adopted in Brazil (10 mGy). The results obtained with both methods were similar when taking into account the estimated uncertainties in the determination of air kerma values, although the reproducibility of the determinations based on the exposure index is better.

  13. Characterization of a computed radiography system for external radiotherapy beam dosimetry

    Aberle, Christoph; Kapsch, Ralf-Peter

    2016-06-01

    A commercial computed radiography (CR) system was studied as an option for quantitative dosimetry quality assurance of external radiotherapy beams. Following the examination of influencing quantities, practical measurement procedures are discussed. Corrections were derived for image fading, an observed long-term response drift and the image length scale, which was found to be off by up to 2–3%. It is known that energy dependence is important for CR measurements. Therefore, signal-to-dose calibration curves and the energy dependence of the response were studied extensively using multiple photon and electron beam qualities. Doses which yield the same signal vary by up to tens of percent for different beam qualities. Results on the directional response of the plates are presented. It was found that rotations of up to 30° to 40° relative to perpendicular irradiation yield no significant change in response. Finally, the homogeneity of the response over the measurement region was studied for electrons and photons and a correction method is described. In summary, relative dose measurements with uncertainties of a few percent are feasible in regions of constant beam energy.

  14. Evaluation of a computed radiography system for megavoltage photon beam dosimetry

    Computed radiography (CR) systems have been gaining adoption as digital replacements for film for diagnostic and therapy imaging. As a result, film processors are being removed from service, leaving a void for the medical physicists who use film and processors for two-dimensional megavoltage beam dosimetry. This is the first report to evaluate the ability of a commercial CR reader and storage phosphor plate system to accurately quantitate absolute dose and dose distributions from a 6 MV photon beam. There are potential advantages and disadvantages of current CR systems compared to film systems. CR systems inherently produce a linear dose-response over several logs of dose. However, the barium in the storage phosphor has a higher atomic number than the silver in film, resulting in significant energy sensitivity. The purpose of this work is to fully characterize the impact of these and other features of this CR system relevant to dosimetry. The tests performed and reported on in this study include uniformity of readout across a uniform field, geometrical accuracy, intra- and interday reproducibility, signal decay with time and with light exposure, dose-to-signal calibration, high dose effects, obliquity effects, perpendicular and parallel calibration results, field size and depth of measurement effects and the use of lead filters to minimize them, and intensity modulated radiation therapy quality assurance test results compared to that for film. Practical techniques are provided to optimize the accuracy of the system as a dosimetric replacement for film

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

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

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

    Desai, Nikunj; Valentino, Daniel J.

    2011-03-01

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

  17. Visualisation of uric acid renal calculi (UARC) using computed radiography (CR)

    Aim: To investigate the capability of CR to visualise UARC through inverse image post-processing technique. Methods. A patient-equivalent phantom (PEP) consisting of six 2.5-cm thick Perspex layers and one 1-mm thick aluminium layer was used to represent human tissues and bones respectively. A total of eight exposures were made on PEP to radiograph 1 mm, 2 mm and 3 mm UARC located between three layers of 2-cm thick cattle muscle, positioned inside the PEP. After each exposure, a layer of Perspex was removed, and another exposure was made until only one Perspex layer and one layer of muscle (containing the three UARC) remained. For each exposure, two images (a positive and an inverse image) were produced for comparison using Fuji XG1 computed radiography system with IP0 type C-ST-VI Fuji imaging plate (equivalent to 400 speed radiographic screen-film systems). Results: In positive image, UARC of all three sizes (1 mm, 2 mm and 3 mm) located in the cattle muscle, cannot be visualised when the PEP consists of more than one layer of Perspex. In inverse image, the 3-mm UARC can be seen even when the PEP consists of five layers of Perspex. Conclusion: This study revealed the post-processing capability of CR to increase the visualisation of UARC which has been categorised as radiolucent. A further study of clinical image quality should be performed using blinded observers to test diagnostic accuracy, which was not included in this study.

  18. Comparison of full field digital (FFD) and computed radiography (CR) mammography systems in Greece.

    Kalathaki, M; Hourdakis, C J; Economides, S; Tritakis, P; Kalyvas, N; Simantirakis, G; Manousaridis, G; Kaisas, I; Kamenopoulou, V

    2011-09-01

    The purpose of this study is to evaluate and compare the performance of 52 full field digital (FFD) and computed radiography (CR) mammography systems checked by the Greek Atomic Energy Commission with respect to dose and image quality. Entrance surface air kerma (ESAK) was measured and average glandular dose (AGD) was calculated according to the European protocol on dosimetry in mammography. The exposures were performed using the clinical protocol of each laboratory. The image quality was assessed by the total score of resolved phantom structures incorporated in an American College of Radiology accreditation phantom. The mean ESAK values for FFD and CR systems were 4.59 ± 1.93 and 5.0 ± 1.78 mGy, respectively, whereas the AGD yielded a mean value of 1.06 ± 0.36 mGy for the FFD and 1.04 ± 0.35 mGy for the CR systems. Considering image quality, FFD systems indicated a mean total score of 13.04 ± 0.89, whereas CR systems a mean total score of 11.54 ± 1.06. PMID:21821614

  19. AP versus PA positioning in lumbar spine computed radiography: Image quality and individual organ doses

    Purpose: Radiological imaging examinations must be optimised in order to ensure that the radiation dose is kept as low as reasonably possible (ALARP). The aim of this study was to compare anteroposterior (AP) and posteroanterior (PA) projections of the lumbar spine, at various kVp increments, in order to establish optimum parameters. Methods: An anthropomorphic phantom was imaged in both the AP/PA projections and at various kVp increments. Acquisitions were undertaken using a Wolverson Acroma X-ray unit and processed using an Agfa computed radiography (CR) unit. The entrance surface dose was recorded and converted to effective and organ doses using PCXMC 2.0 software. Five observers were then asked to evaluate the images, using a two-alternative force choice (2AFC) approach and a scale based on EC guidelines. Results: The PA projection lowered the mean effective dose by 19.8% and also the mean absorbed dose to the stomach (70.4%), colon (61.1%), remainder tissues (33.2%), ovaries (7.3%) and testes (15.9%). However, this was at the expense of slightly inferior image quality, not statistically significant. For AP projections, a higher kVp is a further option for dose reduction. Conclusion: Dose optimisation requires the production of an image that is acceptable for the purpose intended. Based on ALARP, and when taking into consideration the dose reductions in this study, it may now be time to routinely use PA projections when imaging the lumbar spine. The use of a higher kVp should also be considered as an option but would be more useful for AP projections. - Highlights: • We compared AP and PA projections for lumbar spine radiography when using CR. • Switching from an AP to a PA projection reduces the radiation dose. • Effective dose and organ dose can be lowered by moving to a PA projection. • Slight reductions in image quality were demonstrated for PA projections. • Higher kVps lower the radiation dose but reduce image quality

  20. A comparative study of computed radiography-based mammography using digital phosphor storage plate and full field digital mammography

    Kanaga Kumari Chelliah

    2013-01-01

    Full Text Available Background: Two digital mammography systems, based on different physical concepts, have been introduced in the last few years namely the full-field digital mammography (FFDM system and computed radiography-based mammography using digital storage phosphor plate (DSPM. Aims: The objective of this study was to compare the image quality for DSPM and FFDM using a grading scale based on previously published articles. Materials and Methods: This comparative diagnostic study was done for 5-month duration at the Breast Clinic. The system used was the Lorad Selenia FFDM system and the Mammomat 3000 Nova DSPM system. The craniocaudal and mediolateral oblique projections were done on both breast on 58 asymptomatic women using both DSPM and FFDM. The mammograms were evaluated for eight criteria of image quality: Tissue coverage, compression, exposure, contrast, resolution, noise, artifact, and sharpness by two independent radiologists. Statistical Analysis: Wilcoxon Signed Rank Test and Weighted Kappa. Results: FFDM was rated significantly better (P < 0.05 for five aspects: Tissue coverage, compression, contrast, exposure, and resolution and equal to DSPM for sharpness, noise, and artifact. Conclusion: FFDM was superior in five aspects and equal to DSPM for three aspects of image quality.

  1. Computed tomographic analysis of urinary calculi

    Newhouse, J.H.; Prien, E.L.; Amis, E.S. Jr.; Dretler, S.P.; Pfister, R.C.

    1984-03-01

    Excised urinary calculi were subjected to computed tomographic (CT) scanning in an attempt to determine whether CT attenuation values would allow accurate analysis of stone composition. The mean, maximum, and modal pixel densities of the calculi were recorded and compared; the resulting values reflected considerable heterogeneity in stone density. Although uric acid and cystine calculi could be identified by their discrete ranges on one or more of these criteria, calcium-containing stones of various compositions, including struvite, could not be distinguished reliably. CT analysis of stone density is not likely to be more accurate than standard radiography in characterizing stone composition in vivo.

  2. Comparative Reject Analysis in Conventional Film-screen and Digital Storage Phosphor Radiography

    The purpose of this work was to gather information about the benefits in patient care caused by the introduction of digital radiography. In particular, the possibility of reducing the number of image repeats and thus unnecessary patient radiation was sought. Waste films of conventional radiography were collected - in digital radiography each image delete command at the post-processing workstation was documented. Rejected images were analysed retrospectively. The overall reject rate was 27.6% in the conventional and 2.3% in the digital department. While in the conventional department the main reason for rejection was 'exposure' and 'others' (i.e. problems related to film handling), the main reason in the digital environment was 'positioning'. Reject analysis yields representative data about the current performance of a radiology department. A marked reduction of repeated X rays and consequently reduced radiation exposure of the patient was clearly shown in this study comparing two differently working radiology departments. This is one of several benefits of digital radiography in patient care. (author)

  3. 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)

  4. Experimental study of the X-ray spectra optimization for computed radiography mammography systems

    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)

  5. Cause analysis of missing diagnosis for vertebral fracture on lateral chest radiography

    Objective: To analyze the cause of missing diagnosis for vertebral fracture on lateral chest radiography. Methods: Lateral chest radiographies of 1638 hospitalized patients (871 males and 767 females) were retrospectively reviewed for identifying vertebral fractures. Their ages ranged from 50 to 91 years with the mean of 63.5 years. Complains and application for chest radiography in all patients were not related to osteoporosis and vertebral fracture. Vertebral fracture and fracture severity were evaluated using Genant's semiquantitative visual method, taking approximately a 20%-25% vertebral height reduction as mild grade, 26%--40% as moderate grade and 41% or greater as severe grade. Evaluation results of the vertebral fracture, original X-ray reports, as well as medical records were compared for further analysis. Results: Eighty-four in 1638 patients showed vertebral fractures on the lateral chest radiographies. Of them, vertebral fractures were reported in 30 cases and 54 patients were not reported on their original X-ray reports. There were 63 vertebral fractures in 54 un-reported patients, most of which were single fracture (75% or 47/63). Grade I fracture accounted for 54% (34/63), Grade II fracture 33% (21/63), while 13% presented grade III fracture (8/63). In all 84 patients with vertebral fractures, only 5 cases (6%) underwent dual energy X-ray absorptiometry (DXA) measurement, 5 cases (6%) were recorded to have vertebral fractures on the medical papers, as well as 15 cases (18%) were prescribed drugs related to the osteoporosis when discharged from hospital. All drugs prescribed for the 15 patients were limited only to calcium. Conclusions: More attention should be paid to osteoporosis by doctors including radiologists. Vertebral fracture on lateral chest radiography should be completely diagnosed, which is helpful for both prevention and treatment. (authors)

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

    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.

  7. 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.

  8. Comparison of computed tomography with radiography as a noninvasive diagnostic technique for chronic nasal disease in dogs

    Computed tomography was evaluated as a noninvasive technique for the diagnosis of chronic nasal disease in dogs. Computed tomographic images, radiographs, and histopathologic findings were compared in 11 dogs with chronic nasal disease. Definitive diagnosis was made following traumatic nasal flush, exploratory surgery, or necropsy. The study included 8 dogs with intranasal tumors, 2 dogs with bacterial rhinitis (Pasteurella sp), and 1 dog with mycotic rhinitis (Aspergillus sp). Computed tomography was superior to radiography in defining the extent of the disease process and in differentiating infectious rhinitis from nasal neoplasms. It defined lesions in the palate, nasopharyngeal meatus, maxillary sinus, caudal ethmoturbinates, and periorbital tissues that were difficult to demonstrate by use of conventional radiography. Tumors appeared as space-occupying lesions that obliterated the turbinates, caused deviation of the nasal septum, and eroded bone. Rhinitis appeared as a cavitating lesion that spared the paranasal sinuses, thickened and distorted the turbinates, and widened the meatus. Although morphologically distinct on computed tomographic images, infectious rhinitis and nasal neoplasms could not be differentiated by attenuation measurements or degree of contrast enhancement. Computed tomography appeared to be a reliable, noninvasive technique for the diagnosis of chronic nasal disease in dogs, and a promising alternative to diagnostic techniques currently in use

  9. Computed image analysis of neutron radiographs

    Similar with X-radiography, using neutron like penetrating particle, there is in practice a nondestructive technique named neutron radiology. When the registration of information is done on a film with the help of a conversion foil (with high cross section for neutrons) that emits secondary radiation (β,γ) that creates a latent image, the technique is named neutron radiography. A radiographic industrial film that contains the image of the internal structure of an object, obtained by neutron radiography, must be subsequently analyzed to obtain qualitative and quantitative information about the structural integrity of that object. There is possible to do a computed analysis of a film using a facility with next main components: an illuminator for film, a CCD video camera and a computer (PC) with suitable software. The qualitative analysis intends to put in evidence possibly anomalies of the structure due to manufacturing processes or induced by working processes (for example, the irradiation activity in the case of the nuclear fuel). The quantitative determination is based on measurements of some image parameters: dimensions, optical densities. The illuminator has been built specially to perform this application but can be used for simple visual observation. The illuminated area is 9x40 cm. The frame of the system is a comparer of Abbe Carl Zeiss Jena type, which has been adapted to achieve this application. The video camera assures the capture of image that is stored and processed by computer. A special program SIMAG-NG has been developed at INR Pitesti that beside of the program SMTV II of the special acquisition module SM 5010 can analyze the images of a film. The major application of the system was the quantitative analysis of a film that contains the images of some nuclear fuel pins beside a dimensional standard. The system was used to measure the length of the pellets of the TRIGA nuclear fuel. (authors)

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

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

    2013-11-21

    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

  11. 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

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

    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

  13. Quantitative kinetic analysis of lung nodules by temporal subtraction technique in dynamic chest radiography with a flat panel detector

    Tsuchiya, Yuichiro; Kodera, Yoshie; Tanaka, Rie; Sanada, Shigeru

    2007-03-01

    Early detection and treatment of lung cancer is one of the most effective means to reduce cancer mortality; chest X-ray radiography has been widely used as a screening examination or health checkup. The new examination method and the development of computer analysis system allow obtaining respiratory kinetics by the use of flat panel detector (FPD), which is the expanded method of chest X-ray radiography. Through such changes functional evaluation of respiratory kinetics in chest has become available. Its introduction into clinical practice is expected in the future. In this study, we developed the computer analysis algorithm for the purpose of detecting lung nodules and evaluating quantitative kinetics. Breathing chest radiograph obtained by modified FPD was converted into 4 static images drawing the feature, by sequential temporal subtraction processing, morphologic enhancement processing, kinetic visualization processing, and lung region detection processing, after the breath synchronization process utilizing the diaphragmatic analysis of the vector movement. The artificial neural network used to analyze the density patterns detected the true nodules by analyzing these static images, and drew their kinetic tracks. For the algorithm performance and the evaluation of clinical effectiveness with 7 normal patients and simulated nodules, both showed sufficient detecting capability and kinetic imaging function without statistically significant difference. Our technique can quantitatively evaluate the kinetic range of nodules, and is effective in detecting a nodule on a breathing chest radiograph. Moreover, the application of this technique is expected to extend computer-aided diagnosis systems and facilitate the development of an automatic planning system for radiation therapy.

  14. Neutron Radiography

    Reddy, A. R.; Rao, M. V. N.

    2012-01-01

    The field of neutron radiography with special reference to isotopic neutron radiography has been reviewed. Different components viz., sources, collimators, imaging systems are described. Various designs of neutron radiography facilities, their relative merits and demerits , the appropriateness of each design depending on the object to be radiographed, and economics of each technique are also dealt. The applications of neutron radiography are also briefly presented.

  15. Detection of radioactive fragments in patients after radiological or nuclear emergencies using computed tomography and digital radiography.

    Ören, Ü; Hansson, M; Mattsson, S; Rääf, C L

    2014-03-01

    A comparison has been carried out between standard-dose computed tomography, non-diagnostic computed tomography and digital radiography with respect to their suitability for detecting radioactive fragments associated with nuclear or radiological events such as debris from radiological dispersal devices. The purpose was to investigate if radiographic imaging is justified for the detection and localisation of radioactive fragments in affected patients. Fragments of uranium (U), copper (Cu), iron (Fe) and volcanic ash with effective diameters ranging from (approximately) 100 to 700 μm were selected. The fragments were positioned at two different locations on an anatomical torso phantom and images were produced with standard-dose CT, non-diagnostic CT and digital radiography. Capsules with radionuclides of (137)Cs, (60)Co and (99m)Tc were also positioned in the phantom and the effective doses were estimated for radionuclide exposures as well as for standard-dose CT, non-diagnostic CT and digital radiography. For standard-dose CT and digital radiography, U, Cu and Fe fragments were detected in sizes down to 100-180, 250-300 and 300-400 μm respectively. For the non-diagnostic CT the results were 180-250 μm (for U), 300-400 μm (for Cu) and 400-500 μm (for Fe). The effective dose from the standard-dose CT, non-diagnostic CT and digital radiography was 5.6, 1.9 and 0.76 mSv. Corresponding doses from (137)Co, (60)Co and (99m)Tc positioned at the site of fragments were in the range of 0.07-0.1, 0.32-0.45 and 0.08-0.09 mSv per MBq during 24 h. We conclude that, for a number of gamma emitters with activity levels on the order of magnitude of megabecquerel, imaging using ionising radiation can be justified since the effective dose from the radionuclides will exceed the dose from the radiological examination. PMID:24566375

  16. Computer aided diagnosis in digital chest radiography: evaluation of pulmonary emphysema in COPD patients

    Coppini, Giuseppe; Ferdeghini, Ezio Maria; Paterni, Marco; Tonelli, Lucia; Bauleo, Carolina; Monti, Simonetta; Miniati, Massimo

    2004-01-01

    Computer-aided quantitative analysis of chest radiographs is a useful tool in describing alterations in lung shape that occur in patients with emphysema. In the present study, the analysis was limited to the lateral chest radiograph, but we expect that the use of the postero-anterior view may further improve the rate of correct classification.

  17. 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

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

    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

  19. Standard versus inverted digital luminescence radiography in detecting pulmonary nodules: A ROC analysis

    Kirchner, Johannes, E-mail: kirchner@akh-hagen.de [Department of Diagnostic and Interventional Radiology, Allgemeines Krankenhaus, Hagen (Germany); Gadek, Darius [Department of Diagnostic and Interventional Radiology, Allgemeines Krankenhaus, Hagen (Germany); Goltz, Jan-Peter [Department of Radiology, University Hospital of Wuerzburg, Wuerzburg (Germany); Doroch-Gadek, Anna; Stückradt, Sven [Department of Diagnostic and Interventional Radiology, Allgemeines Krankenhaus, Hagen (Germany); Liermann, Dieter [Department of Radiology, Katholisches Marienhospital Herne, Ruhr- University, Bochum (Germany); Kickuth, Ralph [Department of Radiology, University Hospital of Wuerzburg, Wuerzburg (Germany)

    2013-10-01

    Objective: Observer performance tests were conducted to compare the effect of presenting digital luminescence radiography (DLR) monitor images in positive mode (“bones black”) or negative mode (“bones white”) in the detectability of subtle lung nodules. Methods: Five radiologists independently reviewed digital radiographs of 55 patients with either (a) a single, small (6–12 mm), non- calcified peripheral nodule confirmed by chest CT (n = 47) or (b) normal finding (n = 8) confirmed by chest CT, respectively. Mean size of pulmonary nodules was 8.3 mm (range 6–12 mm, median 7 mm). Radiographs were displayed either in standard mode (bones white) or inverse intensity (bones black). A total of 550 observations resulted. For the evaluation ROC analysis was performed using a specialized computer algorithm. Results: The standard presentation mode showed a sensitivity of 61.7% and a specificity of 72.5%, the inverse presentation mode a sensitivity of 68.1% and a specificity of 75.0%. ROC- analysis showed that the difference between the standard mode (Az- value 0.694) and the inverse mode (Az- value 0.810) was significant in favour of the inverse presentation mode (p = 0.001). This finding was especially observed in more experienced radiologist (Az- values 0.716 vs. 0.909, P < 0.001). Conclusion: Our study demonstrates a significant advantage of the inverse mode in the detection of small pulmonary nodules compared with the commonly used negative mode when interpreted by more experienced radiologists. Advance in knowledge: Inverse intensity images (“bones black”) may have some advantages in the detection of small pulmonary nodules in experienced readers when presented on a stand-alone display.

  20. 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.

  1. Non-destructive analysis of rape plant pod by neutron radiography

    Since the ripening process of the rape plant pod has not been studied well, non-destructive analysis of the pod has been carried out by neutron radiography. From the water distribution in the pod, the formation of pod parenchyma as well as vascular system were clearly observed. During the ripening process of the pod water content and weight of the seed were measured. It was found that at the early stage of the ripening process the water content of the seed became maximum and began to decrease, whereas the weight of each seed was gradually increased throughout the ripening process. Neutron radiography, which shows the water content of the pod, will give the clue to the decrease of the water content of the seed from the middle of the ripening process. (author)

  2. Comparative reject analysis in conventional film-screen and digital storage phosphor radiography

    The aim of this study was comparative analysis of rejected radiographs in conventional and digital radiology under the aspects number of rejected images and reasons for rejection. During 2 months waste films of conventional radiography were collected; in digital radiography each image-delete command at the postprocessing workstation was documented. Rejected images were analysed and assigned to four categories. The overall reject rate was 27.6 % in the conventional and 2.3 % in the digital department. Whereas in the conventional department the main reason for rejection was ''exposure'' and ''others'' (i. e. problems related to film handling), the main reason in the digital environment was ''positioning''. The high exposure tolerance of digital systems markedly reduces the amount of faulty images. This is not only economically rewarding, but may also reduce unnecessary X-ray exposure of patients due to image retake. (orig.)

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

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

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

    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

  5. 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.)

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

    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.)

  7. Gamma radiography and its technological application

    After the presentation of gamma radiography and X-ray radiography, the author compare both techniques showing, in particular, the greater utility of gamma radiography in industrial diagnostic and more particularly on works site diagnostic. Problem of using radiography and safety consideration will be studied. Figures shows two radiography equipment which have been designed for gamma radiography respecting the safety regulations required by the Radioisotope Inter-ministerial Commission. In the second part, different techniques and uses of gamma radiography are briefly described : xerography, neutron radiography, fluoroscopy and imaging amplifier, tomography, betatrons and linear accelerators. Cost analysis will discussed in conclusion. (M.P.)

  8. Parameter analysis of radiography film for TC use

    The possibilities of use x-ray industrial films on the projection survey for image processing, jointly with the noise analysis in films, when used as a radiation detectors in computerized tomography are studied. (C.G.C.)

  9. Central axis dose verification in patients treated with total body irradiation of photons using a Computed Radiography system

    To propose and evaluate a method for the central axis dose verification in patients treated with total body irradiation (TBI) of photons using images obtained through a Computed Radiography (CR) system. It was used the Computed Radiography (Fuji) portal imaging cassette readings and correlate with measured of absorbed dose in water using 10 x 10 irradiation fields with ionization chamber in the 60Co equipment. The analytical and graphic expression is obtained through software 'Origin8', the TBI patient portal verification images were processed using software ImageJ, to obtain the patient dose. To validate the results, the absorbed dose in RW3 models was measured with ionization chamber with different thickness, simulating TBI real conditions. Finally it was performed a retrospective study over the last 4 years obtaining the patients absorbed dose based on the reading in the image and comparing with the planned dose. The analytical equation obtained permits estimate the absorbed dose using image pixel value and the dose measured with ionization chamber and correlated with patient clinical records. Those results are compared with reported evidence obtaining a difference less than 02%, the 3 methods were compared and the results are within 10%. (Author)

  10. Computer Programming Job Analysis

    Debdulal Dutta Roy

    2002-01-01

    This study investigated relative uses of computer programming job characteristics across different organizations and effects of different demographic variables on job analysis ratings. Data were collected from 201 computer programers of 6 different organizations through checklist. Principal component analysis noted four mostly used job characteristics as program writing and testing, human relations, data analysis and user satisfaction. Of them only data analysis differed among different organ...

  11. Radiography - A conceptual approach

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

  12. Detection of moisture behavior in building materials in isothermal state by neutron radiography and numerical analysis

    This research focused on the water absorption behavior in water retentive materials and water permeable materials, by using the neutron radiography technique. The moisture characteristic curve, which is hydraulic diffusivity as a function of volumetric moisture content, was calculated with pore size distribution of the both materials, and an unsteady water diffusion analysis was conducted. The experimentally observed water behaviors by the absorption test were well captured by the diffusion analysis. And also the results showed that the gravity effect for calculation of water movement in the water retentive and permeable materials was considerable in comparably rapid water movement. (author)

  13. 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.)

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

    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.)

  15. 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.

  16. Neutron Radiography

    A. R. Reddy

    1982-07-01

    Full Text Available The field of neutron radiography with special reference to isotopic neutron radiography has been reviewed. Different components viz., sources, collimators, imaging systems are described. Various designs of neutron radiography facilities, their relative merits and demerits , the appropriateness of each design depending on the object to be radiographed, and economics of each technique are also dealt. The applications of neutron radiography are also briefly presented.

  17. Correct averaging in transmission radiography: Analysis of the inverse problem

    Wagner, Michael; Hampel, Uwe; Bieberle, Martina

    2016-05-01

    Transmission radiometry is frequently used in industrial measurement processes as a means to assess the thickness or composition of a material. A common problem encountered in such applications is the so-called dynamic bias error, which results from averaging beam intensities over time while the material distribution changes. We recently reported on a method to overcome the associated measurement error by solving an inverse problem, which in principle restores the exact average attenuation by considering the Poisson statistics of the underlying particle or photon emission process. In this paper we present a detailed analysis of the inverse problem and its optimal regularized numerical solution. As a result we derive an optimal parameter configuration for the inverse problem.

  18. The analysis of the imaging speed of the neutron digital radiography system based CCD

    The imaging speed is the main character of the neutron digital radiography system, and the calculating method of neutron digital radiography based CCD is put forward according to the characters of CCD and the principal of neutron digital radiography and optics. Then the imaging speed of neutron radiography system in SPRR-300 is calculated by the method. The experiment shows the counted value basically tallies with the measured value, then the calculating method is believable. (authors)

  19. 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.

  20. National data analysis of general radiography projection method in medical imaging

    According to database of medical institutions of health insurance review and assessment service in 2013, 1,118 hospitals and clinics have department of radiology in Korea. And there are CT, fluoroscopic and general radiographic equipment in those hospitals. Above all, general radiographic equipment is the most commonly used in the radiology department. And most of the general radiographic equipment are changing the digital radiography system from the film-screen types of the radiography system nowadays. However, most of the digital radiography department are used the film-screen types of the radiography system. Therefore, in this study, we confirmed present conditions of technical items for general radiography used in hospital and research on general radiographic techniques in domestic medical institutions. We analyzed 26 radiography projection method including chest, skull, spine and pelvis which are generally used in the radiography department

  1. National data analysis of general radiography projection method in medical imaging

    Kim, Jung Su; Seo, Deok Nam; Choi, In Seok [Dept. of Bio-Convergence Engineering, Korea University Graduate School, Seoul (Korea, Republic of); and others

    2014-09-15

    According to database of medical institutions of health insurance review and assessment service in 2013, 1,118 hospitals and clinics have department of radiology in Korea. And there are CT, fluoroscopic and general radiographic equipment in those hospitals. Above all, general radiographic equipment is the most commonly used in the radiology department. And most of the general radiographic equipment are changing the digital radiography system from the film-screen types of the radiography system nowadays. However, most of the digital radiography department are used the film-screen types of the radiography system. Therefore, in this study, we confirmed present conditions of technical items for general radiography used in hospital and research on general radiographic techniques in domestic medical institutions. We analyzed 26 radiography projection method including chest, skull, spine and pelvis which are generally used in the radiography department.

  2. Position of the impacted third molar in relation to the mandibular canal. Diagnostic accuracy of cone beam computed tomography compared with panoramic radiography.

    Ghaeminia, H.; Meijer, G.J.; Soehardi, A.; Borstlap, W.A.; Mulder, J.; Berge, S.J.

    2009-01-01

    This study investigated the diagnostic accuracy of cone beam computed tomography (CBCT) compared to panoramic radiography in determining the anatomical position of the impacted third molar in relation with the mandibular canal. The study sample comprised 53 third molars from 40 patients with an incr

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

    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. (author)

  4. Influence of imaging factors on image quality in bovine computed radiography (CR) using portable X-ray equipment

    The purpose of this study was to investigate the effect of X-ray tube-cassette distance and image scanning time on image quality to establish the benefit of Computed Radiography (CR) in bovine clinical practice. The tube-cassette distance had no effect on the visual evaluation score (graininess and sharpness). The image scanning time correlated with graininess but not sharpness. From these results, it was concluded that accidental variations in the tube-cassette distance and variations in image scanning time of several hours will not be major problems in clinical practice. CR is considered a useful X-ray system in bovine clinical imaging in which the maintenance of reproducible tube-cassette distance is difficult and variations in image scanning time is assumed

  5. Evaluation of an edge method for computed radiography and an electronic portal imaging device in radiotherapy: Image quality measurements

    Son, Soon-Yong; Choe, Bo-Young; Lee, Jeong-Woo; Kim, Jung-Min; Jeong, Hoi-Woun; Kim, Ham-Gyum; Kim, Wha-Sun; Lyu, Kwang-Yeul; Min, Jung-Whan; Kim, Ki-Won

    2014-12-01

    Regular quality assurance (QA) of image quality is essential for reasonable patient dose and accurate treatment. Thus, QA should be performed as a routine for correction. The purpose of this study was to evaluate the modulation transfer function (MTF), the noise power spectrum (NPS) and the detective quantum efficiency (DQE) of the computed radiography (CR) system and the digital radiography (DR) system by using the edge method in megavoltage X-ray imaging (MVI). We used an edge block, which consisting of tungsten with dimensions of 19 (thickness) × 10 (length) × 1 (width) cm3 and measured the pre-sampling MTF by using a 6-megavolt (MV) energy. Computed radiography with an image plate (CR-IP) showed the values of 0.4 mm-1 and 1.19 mm-1 for MTF 0.5 and 0.1. In the DR group, Elekta iViewGT showed the highest value of 0.27 mm-1 for MTF 0.5, and Siemens BEAMVIEW PLUS showed the highest value of 0.98 mm-1 for MTF 0.1. In CR, the NPS of CR-IP showed a favorable noise distribution. Thus, in the DR group, the NPS of Elekta iViewGT showed the highest noise distribution. CR-IP showed values at peak DQE and 1 mm-1 DQE of 0.0013 and 0.00011, respectively. In the DR group, Elekta iViewGT showed the best efficiency at a peak DQE of 0.0009, and Siemens BEAMVIEW PLUS showed the best efficiency at a 1-mm-1 DQE of 0.000008. The edge method produced fast assessments of the MTF and the DQE. We could validate the evaluation of the edge method by comparing of the CR system to the DR system. This study demonstrated that the edge method can be used for not only traditional QA imaging but also quantitative MTF, NPS and DQE measurements in detector development.

  6. Control dose in chest radiography after the installation of the computed radiography; Control de dosis impartidas en radiografia de torax tras la instalacion de un sistema de radiografia computerizada

    Minano Herrero, J. A.; Solar Cantos, M. M.; Roldan Arjona, J. M.; Martinez Cobos, R.

    2006-07-01

    The aim of this work is to verify patient does after the installation of the computed radiography. Entrance surface doses were obtained from a measurement of the output of the x-ray tube and exposure factor used at posteroanterior (PA) and lateral (LAT) chest in 50 adult patients before and after the installation. The obtained average values were 0.28{+-}0.10mGy in the PA view and 0.8{+-}0.5 mGy in the LAT view with the conventional screen-film system 0.27{+-}0.06 mGy in PA view and 0.69{+-}0.18 mGy in LAT view with the digital radiography system. The results do not exceed the diagnostic reference levels (DRLs) and are constant after the change of system. (Author)

  7. neutron radiography

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

  8. Optimization of digital chest radiography using computer modeling and voxels phantoms

    The purpose of this work is to use the Monte Carlo code MCNPX and the Female Adult voxel (FAX) and Male Adult voxel (MAX) phantoms to investigate how the dose and image quality in digital chest radiography vary with tube voltage (70-150 kV), anti-scatter methods (grid and air gap) and gender of the patient. The effective dose was calculated by ICRP60 and image quality was quantified by calculating the signal-difference-to-noise ratio for pathological details (calcifications) positioned at different locations in the anatomy. Calculated quantities were normalized to a fixed value of air kerma (5 μGy) at the automatic exposure control chambers. The results obtained in this work show that the air gap technique and lower tube voltages provide an increase in the digital image quality. Furthermore, this study has also shown that the detection of pathological details vary with the gender of the patient. (author)

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

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

  10. Computational Music Analysis

    This book provides an in-depth introduction and overview of current research in computational music analysis. Its seventeen chapters, written by leading researchers, collectively represent the diversity as well as the technical and philosophical sophistication of the work being done today in this...... well-established theories in music theory and analysis, such as Forte's pitch-class set theory, Schenkerian analysis, the methods of semiotic analysis developed by Ruwet and Nattiez, and Lerdahl and Jackendoff's Generative Theory of Tonal Music. The book is divided into six parts, covering...... music analysis, the book provides an invaluable resource for researchers, teachers and students in music theory and analysis, computer science, music information retrieval and related disciplines. It also provides a state-of-the-art reference for practitioners in the music technology industry....

  11. Comparative of radiation dose and image quality of Conventional Multislice Computed Tomography (MSCT, Cone-Beam CT (CBCT and periapical radiography in dental imaging

    Nasrollah Jabbari

    2016-03-01

    Full Text Available Background and Aims: With the increasing use of CT (Computed Tomoghraphy scans in dentistry especially in the implantology, there may be significant increases in the radiation exposure and its risk. During the last year’s ConeBeam Computed Tomoghraphy (CBCT has been introduced as an imaging modality for dentistry. The aim of this review article was to present comprehensive information have been published, regarding the  radiation dose and image quality of Conventional Multislice Computed Tomography (MSCT, Cone-Beam CT (CBCT and periapical radiography in dentistry imaging. Materials and Methods: A review of the literature was carried out in PubMed, Google Scholar, Science Direct and Scopus database using key words (CBCT, MSCT, periapical radiography, radiation dose of dentistry and image quality. These searches were limited to the articles published between the years of 1993 to 2015. Conclusion: In comparison to MSCT, CBCT had a short scanning times and lower radiation dose, but in comparison to periapical radiography, CBCT had higher radiation dose. In contrast, CBCT with flat panel detector had higher spatial resolution to MSCT. The periapical radiography also had a good image contrast and relatively high resolution. Generally, CBCT was suitable for hard tissue imaging and MSCT was preferred for soft tissue imaging.

  12. A comparative study of cone-beam computed tomography and digital periapical radiography in detecting mandibular molars root perforations

    The aim of this in vitro study was to determine the sensitivity and specificity of cone-beam computed tomography (CBCT) and digital periapical radiography in the detection of mesial root perforations of mandibular molars. In this in vitro study, 48 mandibular molars were divided into 4 groups. First, the mesial canals of all the 48 teeth were endodontically prepared. In 2 groups (24 teeth each), the roots were axially perforated in the mesiolingual canal 1-3 mm below the furcation region, penetrating the root surface (root perforation). Then, in one of these 2 groups, the mesial canals were filled with gutta-percha and AH26 sealer. Mesial canals in one of the other 2 groups without perforation (control groups) were filled with the same materials. The CBCT and periapical radiographs with 3 different angulations were evaluated by 2 oral and maxillofacial radiologists. The specificity and sensitivity of the two methods were calculated, and P<0.05 was considered significant. The sensitivity and specificity of CBCT scans in the detection of obturated root canal perforations were 79% and 96%, respectively, and in the case of three-angled periapical radiographs, they were 92% and 100%, respectively. In non-obturated root canals, the sensitivity and specificity of CBCT scans in perforation detection were 92% and 100%, respectively, and for three-angled periapical radiographs, they were 50% and 96%, respectively. For perforation detection in filled-root canals, periapical radiography with three different horizontal angulations would be trustworthy, but it is recommended that CBCT be used for perforation detection before obturating root canals.

  13. A comparative study of cone-beam computed tomography and digital periapical radiography in detecting mandibular molars root perforations

    Haghanifar, Sina; Moudi, Ehsan; Mesgarani, Abbas; Abbaszadeh, Naghi [Dental Material Research Center, Dental Faculty, Babol University of Medical Sciences, Babol (Iran, Islamic Republic of); Bijani, Ali [Non-Communicable Pediatric Diseases Research Center, Babol University of Medical Sciences, Babol (Iran, Islamic Republic of)

    2014-06-15

    The aim of this in vitro study was to determine the sensitivity and specificity of cone-beam computed tomography (CBCT) and digital periapical radiography in the detection of mesial root perforations of mandibular molars. In this in vitro study, 48 mandibular molars were divided into 4 groups. First, the mesial canals of all the 48 teeth were endodontically prepared. In 2 groups (24 teeth each), the roots were axially perforated in the mesiolingual canal 1-3 mm below the furcation region, penetrating the root surface ({sup r}oot perforation{sup )}. Then, in one of these 2 groups, the mesial canals were filled with gutta-percha and AH26 sealer. Mesial canals in one of the other 2 groups without perforation (control groups) were filled with the same materials. The CBCT and periapical radiographs with 3 different angulations were evaluated by 2 oral and maxillofacial radiologists. The specificity and sensitivity of the two methods were calculated, and P<0.05 was considered significant. The sensitivity and specificity of CBCT scans in the detection of obturated root canal perforations were 79% and 96%, respectively, and in the case of three-angled periapical radiographs, they were 92% and 100%, respectively. In non-obturated root canals, the sensitivity and specificity of CBCT scans in perforation detection were 92% and 100%, respectively, and for three-angled periapical radiographs, they were 50% and 96%, respectively. For perforation detection in filled-root canals, periapical radiography with three different horizontal angulations would be trustworthy, but it is recommended that CBCT be used for perforation detection before obturating root canals.

  14. Computed radiography plus rhythm software platform for FAC inspection in nuclear secondary circuit

    Koetz, A.; Delannoy, L. [GE Sensing and Inspection Technologies, Skaneateles (United States); Knook, T. [EDF DTG, Grenoble (France)

    2011-07-01

    This paper will cover determining and ensuring proper follow up of Flow Accelerated Corrosion (FAC) in secondary circuit of Nuclear Power Plant using digital radiography. What are the relevant parameters on the pipes and weld wall thickness reading. How precise and reliable are the data and how best to record and archive. One challenge always faced with inspections is how to share the data and gain expert opinion when the expert is on-site; with digital inspection data and the use of software tools this challenge can be overcome. As you begin to collect all the inspection data the true 'power of the data' can be unfolded. Archiving of digital inspection data provides the foundation of asset management, allowing you to look at trends over time throughout inspection results done in one plant or multiple locations around the world. This document describes the process and results of tests performed through digital radiographic technic for the detection and sizing of thickness losses in weld roots areas. The tests were performed according to a pre-established program including a phase of testing on standard blocks and tubes and a phase of testing on components with real defects. (authors)

  15. Computer aided safety analysis

    The document reproduces 20 selected papers from the 38 papers presented at the Technical Committee/Workshop on Computer Aided Safety Analysis organized by the IAEA in co-operation with the Institute of Atomic Energy in Otwock-Swierk, Poland on 25-29 May 1987. A separate abstract was prepared for each of these 20 technical papers. Refs, figs and tabs

  16. Accuracy of radiography and computed tomography in the diagnosis of distal radio-ulnar joint congruity in rheumatoid hands

    Yamaguchi, Michio; Kawakita, Hirofumi; Ogawa, Ryokei; Minamikawa, Yoshitaka; Kojima, Shin; Morimoto, Tadanobu; Yakura, Hisayoshi; Iida, Hirosuke

    1988-01-01

    We investigated the accuracy of radiography and computed tomography in the diagnosis of distal radio-ulnar joint (DRUJ) congruity in 10 healthy hands and 84 rheumatoid hands. Operated-on joints were excluded from this series. The CT study of DRUJ was done in positions of 90 deg, 70 deg, 45 deg, 20 deg and 0 deg in pronation and supination of the forearm. The radiographic study was done of the lateral view of the wrist with the forearm in neutral rotation, and of the P-A view with the forearm in full pronation. The evaluation was done with Mino's and Snook's criteria. All computed tomograms showed good congruity in the 10 healthy hands, so we evaluated radiograms using these results. In healthy hands, the accuracy of the lateral radiograms was 60 % and of the P-A view ones' 80 %. In the computed tomograms, good congruity was noted in 29 joints, subluxation in 57 joints and dislocation in no joints in 84 rheumatoid hands clinically diagnosed as having DRUJ incongruity. The accuracy of the lateral view radiograms was 60.5 % and of the P-A view ones' 35.7 %. Evaluation of the P-A view radiogram was impossible in 18.9 % due to bony destruction of the ulnar styloid process in RA. In the lateral view radiograms of 23 joints which showed subluxation in natural rotation by computed tomography, subluxation was noted in 11 joints, good congruity in 8 joints and dislocation in 4 joints. This study suggests that as the radiographic evaluation of DRUJ incongruity is difficult in rheumatoid hands because of severe bony and articular destruction, computed tomography is necessary for the diagnosis of DRUJ subluxation.

  17. The accuracy of radiography and computed tomography in the diagnosis of distal radio-ulnar joint congruity in rheumatoid hands

    We investigated the accuracy of radiography and computed tomography in the diagnosis of distal radio-ulnar joint (DRUJ) congruity in 10 healthy hands and 84 rheumatoid hands. Operated-on joints were excluded from this series. The CT study of DRUJ was done in positions of 90 deg, 70 deg, 45 deg, 20 deg and 0 deg in pronation and supination of the forearm. The radiographic study was done of the lateral view of the wrist with the forearm in neutral rotation, and of the P-A view with the forearm in full pronation. The evaluation was done with Mino's and Snook's criteria. All computed tomograms showed good congruity in the 10 healthy hands, so we evaluated radiograms using these results. In healthy hands, the accuracy of the lateral radiograms was 60 % and of the P-A view ones' 80 %. In the computed tomograms, good congruity was noted in 29 joints, subluxation in 57 joints and dislocation in no joints in 84 rheumatoid hands clinically diagnosed as having DRUJ incongruity. The accuracy of the lateral view radiograms was 60.5 % and of the P-A view ones' 35.7 %. Evaluation of the P-A view radiogram was impossible in 18.9 % due to bony destruction of the ulnar styloid process in RA. In the lateral view radiograms of 23 joints which showed subluxation in natural rotation by computed tomography, subluxation was noted in 11 joints, good congruity in 8 joints and dislocation in 4 joints. This study suggests that as the radiographic evaluation of DRUJ incongruity is difficult in rheumatoid hands because of severe bony and articular destruction, computed tomography is necessary for the diagnosis of DRUJ subluxation. (author)

  18. Use of cost benefit analysis in the field of industrial radiography

    Over the past decade NRPB has had a program of work on the development of cost benefit analysis (CBA) techniques in the optimisation of radiological protection. A provisional framework for including suggestions for assigning a value to unit collective dose was published for consultation in 1981/82 and after various interim statements this process culminated in formal advice in 1986. As part of this work, and as part of a project for the Commission of the European Communities (CEC) the NRPB has carried out a number of case studies to demonstrate the practical implementation of ALARA or optimisation of protection using CBA. These techniques, used in conjunction with ALARA audits, are now in general use in the NRPB's Radiation Protection Advisor Service. They have been used for a variety of medical and industrial situations, but mainly in industrial radiography as this is the part of the non-nuclear sector where occupational exposure problems predominate. Three cases are presented as representative examples

  19. Computer-aided diagnosis for the detection of the pulmonary nodules on digital chest radiography in lung cancer screening

    Objective: To evaluate the value of computer-aided detection (CAD) system for pulmonary nodule detection using digital chest radiography in lung cancer screening. Methods: One hundred consecutive digital chest radiographs from 6280 outpatients for lung cancer screening were independently reviewed by a thoracic radiologist and a computer-aided pulmonary nodule detection system. The radiographs were also reviewed by two experienced thoracic radiologists and the true nodules confirmed by two radiologists with reference to the CT images were marked and stored as a gold standard in the CAD system. The sensitivity and false positive of the radiologist and the CAD system for the detection of nodules on digital chest radiographs were compared. Results: Ninety-five and 304 nodules were identified by radiologist and the CAD system, respectively. Of 134 nodules marked as true nodules by experienced radiologists, 82 (61.2%) and 105 (78.4%) nodules were identified by the radiologist and the CAD, respectively. The radiologist missed 35 true nodules which were only detected by CAD. The CAD system missed 10 true nodules which were only detected by radiologist. One hundred and twelve (83.6%) nodules were identified by radiologist with the CAD system. One hundred and ninety-nine nodules identified by CAD were false-positive with a rate of 2.0 (199/100) per case. Conclusion: Combining review of digital radiographs by radiologist with CAD system can improve the detection of pulmonary nodules in lung cancer screening. (authors)

  20. 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. PMID:27090952

  1. 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.

  2. Digital radiography vs conventional radiography - a comparison along with its image quality and benefits

    In digital radiography, information is represented in the form of discrete units, i.e., numbers, and involve the use of computers, whereas in conventional radiography, information is represented in analog or continuous form rather than in discrete fashion

  3. Changes of radiation dose and image quality due to additional filtration material in computed radiography

    Filter absorbs low-energy X-ray to increase the average energy and reduces patient exposure dose. This study investigates if the materials of Mo and W could be used for the digital imaging device CR by conducting image assessment and dose measurement of SNR, FOM and histogram. In addition, measurement of beam quality was conducted depending on the material of the filter, and at the same time, a proper combination of filters was examined depending on the change in tube voltage (kVp). In regard to entrance skin dose, Mo filter showed the dose reduction by 42∼56%, compared to Cu filter. Moreover, Mo filter showed higher transmission dose by around 1.5 times than that of Cu filter. In image assessment, it was found that W was unsuitable to be used as a filter, whereas Mo could be used as a filter to reduce dose without decline in image quality at the tube voltage of 80 kVp or higher. As tube voltage increased, 2.0 mm Al+0.1 mm Mo almost had a similar histogram width to that of 2.0 mm Al+0.2 mm Cu. Therefore, Mo filter can be used at relatively high tube voltage of 80 kVp, 100 kVp and 120 kVp. The SNR of 2.0 mm Al+0.1 mm Mo did not show any significant difference from those of 2.0 mm Al+0.2 mm Cu and 2.0 mm Al+0.1 mm Cu. As a result, if Mo filter is used to replace Cu filter in general radiography, where 80 kVp or higher is used for digital radiation image, patient exposure dose can be reduced significantly without decline in image quality, compared to Cu filter. Therefore, it is believed that Mo filter can be applied to chest X-ray and high tube voltage X-ray in actual clinical practice

  4. Computational Music Analysis

    2016-01-01

    This book provides an in-depth introduction and overview of current research in computational music analysis. Its seventeen chapters, written by leading researchers, collectively represent the diversity as well as the technical and philosophical sophistication of the work being done today in this intensely interdisciplinary field. A broad range of approaches are presented, employing techniques originating in disciplines such as linguistics, information theory, information retrieval, pattern r...

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

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

  6. Detectability of simulated pulmonary nodules on chest radiographs: Comparison between irradiation side sampling indirect flat-panel detector and computed radiography

    Objective: To compare the detectability of simulated pulmonary nodules on chest radiographs between an irradiation side sampling indirect flat-panel detector (ISS-FPD) and computed radiography (CR). Materials and methods: This study was an observer performance study. Simulated pulmonary nodules of 8 mm in diameter were superimposed on an anthropomorphic chest phantom. Chest radiographs were acquired under 2 exposure levels (4 and 3.2 mAs) with the ISS-FPD and the CR. Six thoracic radiologists evaluated all 40 images (10 patterns × 2 different exposure doses × 2 different systems) for the presence or absence of a lesion over each of 12 defined areas on a 3-megapixel monochrome liquid-crystal display. Receiver operating characteristic (ROC) curves were obtained for observation in predefined 480 areas. A jackknife method was used for statistical analysis. Differences with a P value of <0.05 were considered significant. Results: The analysis of the observer detection of simulated pulmonary nodules showed larger areas under the ROC curve (AUC) by the ISS-FPD than by the CR. There was a statistically significant difference between the two systems at 3.2 mAs (P = 0.0330). Conclusion: The ISS-FPD was superior to the CR for the detection of simulated pulmonary nodules at 3.2 mAs

  7. Fundamental analysis and algorithms for development of a mobile fast-scan lateral migration radiography system

    Su, Zhong

    Lateral migration radiography (LMR) is a unique x-ray Compton backscatter imaging (CBI) technique to image surface and subsurface, or internal structure of an object. An x-ray pencil beam scans the interrogated area and the backscattered photons are registered by detectors which have varying degrees of collimation. In early LMR applications, either the LMR systems or the imaged objects are moved on a rectangular grid, and at each node, the systems register backscattered photon energy deposition as pixel intensity in acquired images. The mechanical movement of the system or objects from pixel to pixel causes prolonged image scan time with a high percentage of system dead time. To avoid this drawback, a particular x-ray beam formation technique is proposed and analyzed. A corresponding mobile, fast-scan LMR system is designed, fabricated and tested. The results show a two orders-of-magnitude reduction in image scan time compared with those of previous systems. The x-ray beam formation technique, based on a rotating collimator in the LMR system, implements surface line scan by sampling an x-ray fan beam. This rotating collimator yields unique imaging effects compared to those for an x-ray beam with fixed collimation and perpendicular incidence: (1) the speed of the x-ray beam spot on the scanned surface is not uniform; (2) constant movement of the x-ray beam spot changes the resolution in the image raster direction; (3) x-ray beam spot size changes with location on the scanned surface; (4) the object image shows a squeezed effect in the raster scan direction; (5) under a uniform background, the Compton scatter angular distribution causes the x-ray backscatter field to be stronger, when the x-ray beam has greater incidence angle; and (6) the x-ray illumination spot trace on the scanned surface is skewed. The physics generating these effects is analyzed with Monte Carlo computer simulations and/or measurements. Image acquisition and image processing algorithms are

  8. A case of complex odontoma in a horse - clinical signs, radiography, ultrasonography and computer tomography

    The clinical signs, diagnosis and pathology of an adult horse with a complex odontoma are described. Computer tomography was shown to be a new diagnostic technique with outstanding potential in the investigation of diseases of the equine head

  9. Comparative examinations of serum pepsinogen I, II and gastric area using computed radiography in the atrophic gastritis

    The relationship between serum PG I, PG II levels and extent of atrophic gastritis was examined. The subjects were 64 patients (male: 32, female: 32, 51.9 years old on average) with established diagnosis of either atrophic gastritis or normal. In the X-ray gastric examination, Fuji Computed Radiography (FCR) was used to obtain clear-cut images of the gastric area. Concerning the serum PG I level, patients in the group with atrophic gastritis showed lower levels than those of the people in the group with no atrophic change, but the variation was wide, and no definite tendency was seen in the relationship between the atrophic change and the serum PG I levels. Concerning the serum PG II level, as the atrophic change progresses, the serum PG II level tended to increase gradually. A significant reduction in the PG I/II ratio was seen in the group with atrophic changes (p<0.01) in comparison with the group with no atrophic changes, and the PG I/II value tended to decrease. In conclusion, as a relationship between the atrophic change and the serum PG levels had a wide variation, we considered it to be difficult to understand the presence and extent of the atrophic gastritis by measuring serum PG levels. (author)

  10. Configuration of automatic exposure control on mammography units for computed radiography to match patient dose of screen film systems

    Yang, Chang-Ying Joseph; Huang, Weidong

    2009-02-01

    Computed radiography (CR) is considered a drop-in addition or replacement for traditional screen-film (SF) systems in digital mammography. Unlike other technologies, CR has the advantage of being compatible with existing mammography units. One of the challenges, however, is to properly configure the automatic exposure control (AEC) on existing mammography units for CR use. Unlike analogue systems, the capture and display of digital CR images is decoupled. The function of AEC is changed from ensuring proper and consistent optical density of the captured image on film to balancing image quality with patient dose needed for CR. One of the preferences when acquiring CR images under AEC is to use the same patient dose as SF systems. The challenge is whether the existing AEC design and calibration process-most of them proprietary from the X-ray systems manufacturers and tailored specifically for SF response properties-can be adapted for CR cassettes, in order to compensate for their response and attenuation differences. This paper describes the methods for configuring the AEC of three different mammography units models to match the patient dose used for CR with those that are used for a KODAK MIN-R 2000 SF System. Based on phantom test results, these methods provide the dose level under AEC for the CR systems to match with the dose of SF systems. These methods can be used in clinical environments that require the acquisition of CR images under AEC at the same dose levels as those used for SF systems.

  11. A comparative study of adult patient doses in film screen and computed radiography in some Sudanese hospitals

    A study was performed to compare adult patient doses in film screen (FS) and computed radiography (CR) diagnostic X-ray examinations in some hospitals in Sudan over a period of 1 y; during this period of time, the CR systems were introduced to replace FS systems. Radiation doses were estimated for 354 patients in five hospitals (two FS units and three CR units). Entrance surface air kerma (ESAK) was estimated from incident air kerma using patient exposure parameters and tube output. Dose calculations were performed using CALDOSE X 3.5 Monte Carlo-based software. In FS, third quartile of ESAK values for skull PA, skull LAT, chest PA, pelvis AP, lumbar spine AP and lumbar spine LAT were 1.5, 1.3, 0.3, 1.9, 2.8 and 5.9 mGy, respectively, while in CR, third quartile of ESAK values for the same examinations were 2.7, 1.7, 0.18, 1.7, 3.2 and 10.8 mGy, respectively. Comparable ESAK values were presented in FS and CR units. The results are important for future dose optimisation and setting national diagnostic reference levels. (authors)

  12. Comparative examinations of serum pepsinogen I, II and gastric area using computed radiography in the atrophic gastritis

    Tatsu, Yoshimitsu; Ogura, Yasuharu; Yamazaki, Kouichi [Osaka Medical Coll., Takatsuki (Japan)] [and others

    1995-11-01

    The relationship between serum PG I, PG II levels and extent of atrophic gastritis was examined. The subjects were 64 patients (male: 32, female: 32, 51.9 years old on average) with established diagnosis of either atrophic gastritis or normal. In the X-ray gastric examination, Fuji Computed Radiography (FCR) was used to obtain clear-cut images of the gastric area. Concerning the serum PG I level, patients in the group with atrophic gastritis showed lower levels than those of the people in the group with no atrophic change, but the variation was wide, and no definite tendency was seen in the relationship between the atrophic change and the serum PG I levels. Concerning the serum PG II level, as the atrophic change progresses, the serum PG II level tended to increase gradually. A significant reduction in the PG I/II ratio was seen in the group with atrophic changes (p<0.01) in comparison with the group with no atrophic changes, and the PG I/II value tended to decrease. In conclusion, as a relationship between the atrophic change and the serum PG levels had a wide variation, we considered it to be difficult to understand the presence and extent of the atrophic gastritis by measuring serum PG levels. (author).

  13. Comparison of Computed Tomography and Chest Radiography in the Detection of Rib Fractures in Abused Infants

    Wootton-Gorges, Sandra L.; Stein-Wexler, Rebecca; Walton, John W.; Rosas, Angela J.; Coulter, Kevin P.; Rogers, Kristen K.

    2008-01-01

    Purpose: Chest radiographs (CXR) are the standard method for evaluating rib fractures in abused infants. Computed tomography (CT) is a sensitive method to detect rib fractures. The purpose of this study was to compare CT and CXR in the evaluation of rib fractures in abused infants. Methods: This retrospective study included all 12 abused infants…

  14. Comparison of panoramic radiography and cone beam computed tomography for assessing the relationship between the maxillary sinus floor and maxillary molars

    This study compared panoramic radiography and cone beam computed tomography (CBCT) for evaluating the relationship between the maxillary sinus floor and the roots of maxillary molars. Paired panoramic radiographs and CBCT images from 97 subjects were analysed. This analysis classified 388 maxillary molars according to their relationship to the maxillary sinus floor on panoramic radiograph and CBCT. Correlations between these two radiographic techniques were examined. Maxillary molar roots that were separate from the sinus floor showed the same classification in 100% of the cases when using these two imaging techniques. The corresponding percentage for such roots that were in contact with the sinus floor was 75%. When roots overlapped the maxillary sinus floor on panoramic radiographs, only 26.4% of maxillary first molars and 60.0% of second molars showed protrusion of roots into the sinus with CBCT. The results of the study suggest that roots projecting into the sinus on panoramic radiographs require a three-dimensional image in order to analyze the proximity of their apex to the sinus floor.

  15. Time resolved analysis of water drainage in porous asphalt concrete using neutron radiography.

    Poulikakos, L D; Sedighi Gilani, M; Derome, D; Jerjen, I; Vontobel, P

    2013-07-01

    Porous asphalt as a road surface layer controls aquaplaning as rain water can drain through its highly porous structure. The process of water drainage through this permeable layer is studied using neutron radiography. Time-resolved water configuration and distribution within the porous structure are reported. It is shown that radiography depicts the process of liquid water transport within the complex geometry of porous asphalt, capturing water films, filled dead end pores and water islands. PMID:23500651

  16. Shielding Benchmark Computational Analysis

    Hunter, H.T.; Slater, C.O.; Holland, L.B.; Tracz, G.; Marshall, W.J.; Parsons, J.L.

    2000-09-17

    Over the past several decades, nuclear science has relied on experimental research to verify and validate information about shielding nuclear radiation for a variety of applications. These benchmarks are compared with results from computer code models and are useful for the development of more accurate cross-section libraries, computer code development of radiation transport modeling, and building accurate tests for miniature shielding mockups of new nuclear facilities. When documenting measurements, one must describe many parts of the experimental results to allow a complete computational analysis. Both old and new benchmark experiments, by any definition, must provide a sound basis for modeling more complex geometries required for quality assurance and cost savings in nuclear project development. Benchmarks may involve one or many materials and thicknesses, types of sources, and measurement techniques. In this paper the benchmark experiments of varying complexity are chosen to study the transport properties of some popular materials and thicknesses. These were analyzed using three-dimensional (3-D) models and continuous energy libraries of MCNP4B2, a Monte Carlo code developed at Los Alamos National Laboratory, New Mexico. A shielding benchmark library provided the experimental data and allowed a wide range of choices for source, geometry, and measurement data. The experimental data had often been used in previous analyses by reputable groups such as the Cross Section Evaluation Working Group (CSEWG) and the Organization for Economic Cooperation and Development/Nuclear Energy Agency Nuclear Science Committee (OECD/NEANSC).

  17. Diagnostic value of computed tomography, radiography and ultrasonography in metacarpophalangeal joint disorders in horses

    V.M.V. Machado; A.C.S. Aguiar; G.F. Viana; N.O. Crosignani; J.N.P. Puoli Filho

    2016-01-01

    In modern society the work and athletic performance of horses has led to a very important animal production sector in which Brazil possesses the third largest horse stock. Among all equine lesions described, metacarpophalangeal (fetlock) joint lesions are considered one of the main causes of lameness. Consequently, there is a need to improve the understanding and diagnosis of these injuries. The most efficient imaging diagnostic methods for the fetlock region are computed tomography, radiogra...

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

    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

  19. Broadening the radiography spectrum

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

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

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

  1. Industrial radiography

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

  2. Optimization of the radiological protection of patients undergoing radiography, fluoroscopy and computed tomography. Final report of a coordinated research project in Africa, Asia and eastern Europe

    Although radiography has been an established imaging modality for over a century, continuous developments have led to improvements in technique resulting in improved image quality at reduced patient dose. If one compares the technique used by Roentgen with the methods used today, one finds that a radiograph can now be obtained at a dose which is smaller by a factor of 100 or more. Nonetheless, some national surveys, particularly in the United Kingdom and in the United States of America in the 1980s and 1990s, have indicated large variations in patient doses for the same diagnostic examination, in some cases by a factor of 20 or more. This arises not only owing to the various types of equipment and accessories used by the different health care providers, but also because of operational factors. The IAEA has a statutory responsibility to establish standards for the protection of people against exposure to ionising radiation and to provide for the worldwide application of those standards. A fundamental requirement of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS), issued by the IAEA in cooperation with the FAO, ILO, WHO, PAHO and NEA, is the optimization of radiological protection of patients undergoing medical exposure. Towards its responsibility of implementation of standards and under the subprogramme of radiation safety, in 1995, the IAEA launched a coordinated research project (CRP) on radiological protection in diagnostic radiology in some countries in the Eastern European, African and Asian region. Initially, the CRP addressed radiography only and it covered wide aspects of optimisation of radiological protection. Subsequently, the scope of the CRP was extended to fluoroscopy and computed tomography (CT), but it covered primarily situation analysis of patient doses and equipment quality control. It did not cover patient dose reduction aspects in fluoroscopy and CT. The project

  3. The application of the Fuji computed radiography system for the diagnosis of pneumoconiosis, 2

    This is the second part of the project shown in the title. Here we developed several image processing procedures to extract quantitative features for diagnostic aid, and to classify sizes and types of pneumoconiosis from chest X-ray films automatically. Those procedures include automated extraction of small round opacities, calculation of the density of opacities, and classification of a given film into two major categories (normal or abnormal), or into more detailed categories such as the type 0, 1, 2, and 3, and the type p, q, and r. Recognition rate was about 60 to 75%, depending on features and sample films used in the experiment. Methods to generate a sketch of a chest X-ray image by computer are also presented. (author)

  4. 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. PMID:9726504

  5. Malignant diffuse pleural mesothelioma: Comparison between computed tomography and conventional plain radiography of the thorax

    The rate of incidence of malignant pleural mesothelioma is increasing although diagnosis of this disease may be very difficult. Computed tomography examinations and conventional chest X-rays of 30 patients with malignant pleural mesothelioma were reviewed independently, to evaluate the role of both modalities. CT offered the following advantages over conventional chest X-ray examinations: Ct was more sensitive in detecting the smooth and nodular changes of malignant pleural mesothelioma, especially at the diaphragm and lower parts of the thorax, tumours could be better demonstrated at the pericardium and in the greater fissure, in some cases, where chest films showed just abnormal widening of the mediastinum, CT could differentiate between tumour involvement of the mediastinal pleura and local invasion of the mediastinum by the tumour CT was more effective in detecting pleural calcifications and thickening of the contralateral pleura. CT proves more accurate in assessing the extent of the disease, and gives additional diagnostic help. (orig.)

  6. 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.

  7. 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.

  8. Pelvic crush fractures in survivors of the Sichuan earthquake evaluated by digital radiography and multidetector computed tomography

    To investigate the profile of pelvic crush fractures in earthquake victims on digital radiography (DR) and multidetector computed tomography (MDCT). One hundred and sixty-seven consecutive survivors of the 2008 Sichuan earthquake with pelvic crush fractures classified into types according to the Tile classification system, entered our study. One hundred and thirty-nine, and 28 patients underwent DR and MDCT scans, respectively. Data were reviewed retrospectively focusing on anatomical sites, numbers, and classification of pelvic ring fractures. Pelvic fractures occurred in the pubis in 88 patients (52.7%), in other pelvic bones in 32 (19.16%), and in both the pubis and other pelvic bones in 47 (28.14%). Pubic fractures were more common than fractures of other pelvic bones, and involvement of bilateral pubis was more common than that of the left or right pubis (all p < 0.05). As for the numbers of pelvic bones involved, multiple fractures occurred in 48.52% patients (81 out of 167) composed predominantly of fractures of two bones in 58.02% (47 out of 81), and were seen more often in bilateral pubis than in any other pelvic bones (p < 0.05). Regarding classifications of pelvic ring fractures, they were Type A in 31 patients (18.56%); Type B in 72 (43.11%), predominantly Type B2 in 26 (15.58%) and Type B3 in 28 (16.77%); and Type C in 64 (38.32%), predominantly Type C3 in 40 (23.95%). Pelvic crush fractures particularly including multiple pelvic fractures, occurring predominantly in bilateral pubis, and composed of Type C3 followed by Type B3 and Type B2, could be considered to be the profile of pelvic crush fractures in an earthquake. (orig.)

  9. 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)

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

    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)