WorldWideScience

Sample records for dose x-ray imaging

  1. Edge enhancement algorithm for low-dose X-ray fluoroscopic imaging.

    Science.gov (United States)

    Lee, Min Seok; Park, Chul Hee; Kang, Moon Gi

    2017-12-01

    Low-dose X-ray fluoroscopy has continually evolved to reduce radiation risk to patients during clinical diagnosis and surgery. However, the reduction in dose exposure causes quality degradation of the acquired images. In general, an X-ray device has a time-average pre-processor to remove the generated quantum noise. However, this pre-processor causes blurring and artifacts within the moving edge regions, and noise remains in the image. During high-pass filtering (HPF) to enhance edge detail, this noise in the image is amplified. In this study, a 2D edge enhancement algorithm comprising region adaptive HPF with the transient improvement (TI) method, as well as artifacts and noise reduction (ANR), was developed for degraded X-ray fluoroscopic images. The proposed method was applied in a static scene pre-processed by a low-dose X-ray fluoroscopy device. First, the sharpness of the X-ray image was improved using region adaptive HPF with the TI method, which facilitates sharpening of edge details without overshoot problems. Then, an ANR filter that uses an edge directional kernel was developed to remove the artifacts and noise that can occur during sharpening, while preserving edge details. The quantitative and qualitative results obtained by applying the developed method to low-dose X-ray fluoroscopic images and visually and numerically comparing the final images with images improved using conventional edge enhancement techniques indicate that the proposed method outperforms existing edge enhancement methods in terms of objective criteria and subjective visual perception of the actual X-ray fluoroscopic image. The developed edge enhancement algorithm performed well when applied to actual low-dose X-ray fluoroscopic images, not only by improving the sharpness, but also by removing artifacts and noise, including overshoot. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Rapid, low dose X-ray diffractive imaging of the malaria parasite Plasmodium falciparum

    International Nuclear Information System (INIS)

    Jones, Michael W.M.; Dearnley, Megan K.; Riessen, Grant A. van; Abbey, Brian; Putkunz, Corey T.; Junker, Mark D.; Vine, David J.; McNulty, Ian; Nugent, Keith A.; Peele, Andrew G.; Tilley, Leann

    2014-01-01

    Phase-diverse X-ray coherent diffractive imaging (CDI) provides a route to high sensitivity and spatial resolution with moderate radiation dose. It also provides a robust solution to the well-known phase-problem, making on-line image reconstruction feasible. Here we apply phase-diverse CDI to a cellular sample, obtaining images of an erythrocyte infected by the sexual stage of the malaria parasite, Plasmodium falciparum, with a radiation dose significantly lower than the lowest dose previously reported for cellular imaging using CDI. The high sensitivity and resolution allow key biological features to be identified within intact cells, providing complementary information to optical and electron microscopy. This high throughput method could be used for fast tomographic imaging, or to generate multiple replicates in two-dimensions of hydrated biological systems without freezing or fixing. This work demonstrates that phase-diverse CDI is a valuable complementary imaging method for the biological sciences and ready for immediate application. - Highlights: • Phase-diverse coherent X-ray diffraction microscopy provides high-resolution and high-contrast images of intact biological samples. • Rapid nanoscale resolution imaging is demonstrated at orders of magnitude lower dose than previously possible. • Phase-diverse coherent X-ray diffraction microscopy is a robust technique for rapid, quantitative, and correlative X-ray phase imaging

  3. Rapid, low dose X-ray diffractive imaging of the malaria parasite Plasmodium falciparum

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Michael W.M., E-mail: michael.jones@latrobe.edu.au [ARC Centre of Excellence for Coherent X-Ray Science, Department of Physics, La Trobe University, Victoria 3086 (Australia); Dearnley, Megan K. [ARC Centre of Excellence for Coherent X-Ray Science, Department of Biochemistry and Molecular Biology, Bio21 Institute, The University of Melbourne, Victoria 3010 (Australia); Riessen, Grant A. van [ARC Centre of Excellence for Coherent X-Ray Science, Department of Physics, La Trobe University, Victoria 3086 (Australia); Abbey, Brian [ARC Centre of Excellence for Coherent X-Ray Science, Department of Physics, La Trobe University, Victoria 3086 (Australia); Melbourne Centre for Nanofabrication, Victoria 3168 (Australia); Putkunz, Corey T. [ARC Centre of Excellence for Coherent X-Ray Science, School of Physics, The University of Melbourne, Victoria 3010 (Australia); Junker, Mark D. [ARC Centre of Excellence for Coherent X-Ray Science, Department of Physics, La Trobe University, Victoria 3086 (Australia); Vine, David J. [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); McNulty, Ian [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Centre for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Nugent, Keith A. [ARC Centre of Excellence for Coherent X-Ray Science, Department of Physics, La Trobe University, Victoria 3086 (Australia); Peele, Andrew G. [ARC Centre of Excellence for Coherent X-Ray Science, Department of Physics, La Trobe University, Victoria 3086 (Australia); Australian Synchrotron, 800 Blackburn Road, Clayton 3168 (Australia); Tilley, Leann [ARC Centre of Excellence for Coherent X-Ray Science, Department of Biochemistry and Molecular Biology, Bio21 Institute, The University of Melbourne, Victoria 3010 (Australia)

    2014-08-01

    Phase-diverse X-ray coherent diffractive imaging (CDI) provides a route to high sensitivity and spatial resolution with moderate radiation dose. It also provides a robust solution to the well-known phase-problem, making on-line image reconstruction feasible. Here we apply phase-diverse CDI to a cellular sample, obtaining images of an erythrocyte infected by the sexual stage of the malaria parasite, Plasmodium falciparum, with a radiation dose significantly lower than the lowest dose previously reported for cellular imaging using CDI. The high sensitivity and resolution allow key biological features to be identified within intact cells, providing complementary information to optical and electron microscopy. This high throughput method could be used for fast tomographic imaging, or to generate multiple replicates in two-dimensions of hydrated biological systems without freezing or fixing. This work demonstrates that phase-diverse CDI is a valuable complementary imaging method for the biological sciences and ready for immediate application. - Highlights: • Phase-diverse coherent X-ray diffraction microscopy provides high-resolution and high-contrast images of intact biological samples. • Rapid nanoscale resolution imaging is demonstrated at orders of magnitude lower dose than previously possible. • Phase-diverse coherent X-ray diffraction microscopy is a robust technique for rapid, quantitative, and correlative X-ray phase imaging.

  4. Low-dose multiple-information retrieval algorithm for X-ray grating-based imaging

    International Nuclear Information System (INIS)

    Wang Zhentian; Huang Zhifeng; Chen Zhiqiang; Zhang Li; Jiang Xiaolei; Kang Kejun; Yin Hongxia; Wang Zhenchang; Stampanoni, Marco

    2011-01-01

    The present work proposes a low dose information retrieval algorithm for X-ray grating-based multiple-information imaging (GB-MII) method, which can retrieve the attenuation, refraction and scattering information of samples by only three images. This algorithm aims at reducing the exposure time and the doses delivered to the sample. The multiple-information retrieval problem in GB-MII is solved by transforming a nonlinear equations set to a linear equations and adopting the nature of the trigonometric functions. The proposed algorithm is validated by experiments both on conventional X-ray source and synchrotron X-ray source, and compared with the traditional multiple-image-based retrieval algorithm. The experimental results show that our algorithm is comparable with the traditional retrieval algorithm and especially suitable for high Signal-to-Noise system.

  5. Commentary: progress in optimization of patient dose and image quality in x-ray diagnostics

    International Nuclear Information System (INIS)

    Carlsson, G.A.; Chan, H.-P.

    1999-01-01

    X-ray diagnostics gives the largest contribution to the population dose from man-made radiation sources. Strategies for reduction of patient doses without loss of diagnostic accuracy are therefore of great interest to society and have been focussed in general terms by the ICRP (ICRP 1996) through the introduction of the concept of diagnostic reference levels. The European Union has stimulated research in the field, and, based on patient dose measurements and radiologists' appreciation of acceptable image quality, good radiographic techniques have been identified and recommended (EUR 1996a, b) for conventional screen-film imaging. These efforts have resulted in notable dose reductions in clinical practices (Hart et al 1996). In spite of 100 years of use of x-rays for diagnostics, the choice of technique parameters still relies to a great extent on experience. Scientific efforts to optimize the choice in terms of finding the parameter settings which yield sufficient image quality at the lowest possible cost in dose are still rare. True optimization requires (1) estimation of the image quality needed to make a correct diagnosis and (2) methods to investigate all possible means of achieving this image quality in order to be able to decide which of them gives the lowest dose. The paper by Tapiovaara, Sandborg and Dance published in this issue of Physics in Medicine and Biology (pages 537-559) addresses the optimization of paediatric fluoroscopy, a timely and important topic. Fluoroscopy procedures, used to guide x-ray examinations or interventional procedures, are little standardized and may result in high dose levels; radiation exposure in childhood is likely to result in a higher lifetime risk than the same exposure later in life. The authors represent an interesting mix of expertise within various scientific fields: the theory of medical imaging and assessment of image quality, the physics of diagnostic radiology and radiation dosimetry. They provide good insights

  6. Optimizing abdominal CT dose and image quality with respect to x-ray tube voltage

    Science.gov (United States)

    Huda, Walter; Ogden, Kent M.

    2004-05-01

    The objective of this study was to identify the x-ray tube voltage that results in optimum performance for abdominal CT imaging for a range of imaging tasks and patient sizes. Theoretical calculations were performed of the contrast to noise ratio (CNR) for disk shaped lesions of muscle, fat, bone and iodine embedded in a uniform water background. Lesion contrast was the mean Hounsfield Unit value at the effective photon energy, and image noise was determined from the total radiation intensity incident on the CT x-ray detector. Patient size ranging from young infants (10 kg) to oversized adults (120 kg), with CNR values obtained for x-ray tube voltages ranging from 80 to 140 kV. Patients of varying sizes were modeled as an equivalent cylinder of water, and the mean section dose (D) was determined for each selected x-ray tube kV value at a constant mAs. For each patient size and lesion type, we identified an optimal kV as the x-ray tube voltage that yields a maximum value of the figure of merit (CNR2/D). Increasing the x-ray tube voltage from 80 to 140 kV reduced lesion contrast by 11% for muscle, 21% for fat, 35% for bone and 52% for iodine, and these reductions were approximately independent of patient size. Increasing the x-ray tube voltage from 80 to 140 kV increased a muscle lesion CNR relative to a uniform water background by a factor of 2.6, with similar trends observed for fat (2.3), bone (1.9) and iodine (1.4). The improvement in lesion CNR with increasing x-ray tube voltage was highest for the largest sized patients. Increasing the x-ray tube voltage from 80 to 140 kV increased the patient dose by a factor of between 5.0 and 6.2 depending on the patient size. For small sized patients (10 and 30 kg) and muscle lesions, best performance is obtained at 80 kV; however, for adults (70 kg) and oversized adults (120 kg), the best performance would be obtained at 140 kV. Imaging fat lesions was best performed at 80 kV for all patients except for oversized adults

  7. Assessment of patient doses and image quality in X-ray diagnostics in Norway

    International Nuclear Information System (INIS)

    Olerud, H.M.

    1998-01-01

    Results from other industrialized countries indicate that the annual number of diagnostic procedures approaches one for every member of the population, and in many cases the individual radiation doses are higher than from any other human activity. Furthermore, the doses to patients for the same type of examination differ widely from place to place, suggesting that there is a considerable potential for dose reduction. This motivated an investigation of the diagnostic use of X-rays in Norway. The trends in the number of X-ray examinations performed annually have been studied. The patient doses (all diagnostics) and image quality (mammography and computed tomography) have been assessed for various radiological procedures. This form the basis for the assessment of total collective effective dose (CED) from X-rays in Norway, and further risk estimates. The radiological practice has then been evaluated according to the radiation protection principles of justification and optimisation. Based on the 1993 examination frequency, the total CED was assessed to 3400 manSv (0.78 mSv/inhabitant). It is estimated that this radiation burden may cause about 100 excess cancer deaths annually. The frequency of CT examination has doubled every fifth year, and did in 1993 represent 7% of the total number of examinations and 30% of the total CED. 129 refs

  8. Assessment of patient doses and image quality in X-ray diagnostics in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Olerud, H M

    1998-06-01

    Results from other industrialized countries indicate that the annual number of diagnostic procedures approaches one for every member of the population, and in many cases the individual radiation doses are higher than from any other human activity. Furthermore, the doses to patients for the same type of examination differ widely from place to place, suggesting that there is a considerable potential for dose reduction. This motivated an investigation of the diagnostic use of X-rays in Norway. The trends in the number of X-ray examinations performed annually have been studied. The patient doses (all diagnostics) and image quality (mammography and computed tomography) have been assessed for various radiological procedures. This form the basis for the assessment of total collective effective dose (CED) from X-rays in Norway, and further risk estimates. The radiological practice has then been evaluated according to the radiation protection principles of justification and optimisation. Based on the 1993 examination frequency, the total CED was assessed to 3400 manSv (0.78 mSv/inhabitant). It is estimated that this radiation burden may cause about 100 excess cancer deaths annually. The frequency of CT examination has doubled every fifth year, and did in 1993 represent 7% of the total number of examinations and 30% of the total CED. 129 refs.

  9. Implementation of a patient dose monitoring system in conventional digital X-ray imaging: initial experiences

    Energy Technology Data Exchange (ETDEWEB)

    Heilmaier, Christina; Zuber, Niklaus; Weishaupt, Dominik [Stadtspital Triemli Zurich, Department of Radiology and Nuclear Medicine, Zurich (Switzerland)

    2017-03-15

    The purpose was to report on the initial experience after implementation of a patient dose-monitoring system in conventional X-ray imaging. A dose-monitoring system collected dose data relating to different radiographs (one projection) and studies (two or more projections). Images were acquired on digital X-ray systems equipped with flat-panel detectors. During period 1, examinations were performed in a routine fashion in 12,614 patients. After period 1, technical modifications were performed and radiographers underwent training in radiation protection. During period 2, examinations were performed in 14,514 patients, and the radiographers were advised to read dose data after each radiograph/study. Dose data were compared by means of kerma area product (KAP, gray x centimetre squared) and entrance surface air kerma (ESAK, milligray). During period 1, 13,955 radiographs and 8,466 studies were performed, and in period 2 16,090 radiographs and 10,389 studies. In period 2, KAP values for radiographs were an average of 25 % lower and for studies 7 % lower, and ESAK values for radiographs were 24 % lower and for studies 5 % lower. The reduction in KAP was significant in 8/13 radiographs and in 6/14 studies, and the reduction in ESAK was significant in 6/13 radiographs and 5/14 studies. Implementation of a patient dose-monitoring system in conventional X-ray imaging allows easy data collection, supports dose reduction efforts, and may increase radiographers' dose awareness. (orig.)

  10. Paediatric x-ray radiation dose reduction and image quality analysis.

    Science.gov (United States)

    Martin, L; Ruddlesden, R; Makepeace, C; Robinson, L; Mistry, T; Starritt, H

    2013-09-01

    Collaboration of multiple staff groups has resulted in significant reduction in the risk of radiation-induced cancer from radiographic x-ray exposure during childhood. In this study at an acute NHS hospital trust, a preliminary audit identified initial exposure factors. These were compared with European and UK guidance, leading to the introduction of new factors that were in compliance with European guidance on x-ray tube potentials. Image quality was assessed using standard anatomical criteria scoring, and visual grading characteristics analysis assessed the impact on image quality of changes in exposure factors. This analysis determined the acceptability of gradual radiation dose reduction below the European and UK guidance levels. Chest and pelvis exposures were optimised, achieving dose reduction for each age group, with 7%-55% decrease in critical organ dose. Clinicians confirmed diagnostic image quality throughout the iterative process. Analysis of images acquired with preliminary and final exposure factors indicated an average visual grading analysis result of 0.5, demonstrating equivalent image quality. The optimisation process and final radiation doses are reported for Carestream computed radiography to aid other hospitals in minimising radiation risks to children.

  11. Paediatric x-ray radiation dose reduction and image quality analysis

    International Nuclear Information System (INIS)

    Martin, L; Ruddlesden, R; Mistry, T; Starritt, H; Makepeace, C; Robinson, L

    2013-01-01

    Collaboration of multiple staff groups has resulted in significant reduction in the risk of radiation-induced cancer from radiographic x-ray exposure during childhood. In this study at an acute NHS hospital trust, a preliminary audit identified initial exposure factors. These were compared with European and UK guidance, leading to the introduction of new factors that were in compliance with European guidance on x-ray tube potentials. Image quality was assessed using standard anatomical criteria scoring, and visual grading characteristics analysis assessed the impact on image quality of changes in exposure factors. This analysis determined the acceptability of gradual radiation dose reduction below the European and UK guidance levels. Chest and pelvis exposures were optimised, achieving dose reduction for each age group, with 7%–55% decrease in critical organ dose. Clinicians confirmed diagnostic image quality throughout the iterative process. Analysis of images acquired with preliminary and final exposure factors indicated an average visual grading analysis result of 0.5, demonstrating equivalent image quality. The optimisation process and final radiation doses are reported for Carestream computed radiography to aid other hospitals in minimising radiation risks to children. (paper)

  12. Effect of area x-ray beam equalization on image quality and dose in digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Jerry; Xu Tong; Husain, Adeel; Le, Huy; Molloi, Sabee [Department of Radiological Sciences, University of California, Irvine, CA 92697 (United States)

    2004-08-21

    In mammography, thick or dense breast regions persistently suffer from reduced contrast-to-noise ratio (CNR) because of degraded contrast from large scatter intensities and relatively high noise. Area x-ray beam equalization can improve image quality by increasing the x-ray exposure to under-penetrated regions without increasing the exposure to other breast regions. Optimal equalization parameters with respect to image quality and patient dose were determined through computer simulations and validated with experimental observations on a step phantom and an anthropomorphic breast phantom. Three parameters important in equalization digital mammography were considered: attenuator material (Z = 13-92), beam energy (22-34 kVp) and equalization level. A Mo/Mo digital mammography system was used for image acquisition. A prototype 16 x 16 piston driven equalization system was used for preparing patient-specific equalization masks. Simulation studies showed that a molybdenum attenuator and an equalization level of 20 were optimal for improving contrast, CNR and figure of merit (FOM = CNR{sup 2}/dose). Experimental measurements using these parameters showed significant improvements in contrast, CNR and FOM. Moreover, equalized images of a breast phantom showed improved image quality. These results indicate that area beam equalization can improve image quality in digital mammography.

  13. A survey in Portuguese X-ray fluoroscopy equipment: dose rates and image quality

    International Nuclear Information System (INIS)

    Teixeira, Nuno G.; Cunha, Gilda R.; Coutinho, Guilherme M.; Trindade, Hugo R.; Carvoeiras, Pedro P.

    2015-01-01

    X-ray fluoroscopy is essential in both diagnosis and medical intervention, although it may contribute to significant radiation doses to patients that have to be optimised and justified. Therefore, it is crucial to the patient to be exposed to the lowest achievable dose without compromising the image quality. The purpose of this study was to perform an analysis of the quality control measurements, particularly dose rates, contrast and spatial resolution of Portuguese fluoroscopy equipment and also to provide a contribution to the establishment of reference levels for the equipment performance parameters. Measurements carried out between 2007 and 2013 on 143 fluoroscopy equipment distributed by 34 nationwide health units were analysed. The measurements suggest that image quality and dose rates of Portuguese equipment are congruent with other studies, and in general, they are as per the Portuguese law. However, there is still a possibility of improvements intending optimisation at a national level. (authors)

  14. Radiation dose to procedural personnel and patients from an X-ray volume imaging system

    International Nuclear Information System (INIS)

    Paul, Jijo; Mbalisike, Emmanuel C.; Vogl, Thomas J.

    2013-01-01

    To evaluate the radiation dose received by procedural personnel and patients from an X-ray volume imaging (XVI) system during interventional procedures. Forty patients were examined using catheter angiography (group A), digital subtraction angiography (group B) and cone-beam CT (CBCT, group C). Doses to procedural personnel (using thermo-luminescent dosimeters, TLDs) and patients were estimated. Image quality and lesion delineation were assessed using objective and subjective methods. Shapiro-Wilk, two-sided Student's t and Wilcoxon matched-pairs tests were used to test statistical significance. Doses (milligrays) measured in the hands and left knee of the interventionist were higher than those in an assistant physician (P < 0.05). Doses (dose-area product and skin entry dose) were lower in group A and higher in C compared with other groups; moreover, comparison among the groups were significant (all P = 0.0001). Subjective and objective lesion delineation showed significant results (all P < 0.05) among the tumour types considered. Image quality estimation showed the opposite results for objective and subjective analysis. More doses were obtained for hands of the procedural personnel compared to other anatomical regions measured. Catheter angiography showed lower dose compared with other imaging groups examined. Lesion delineation was clearly possible using CBCT. Objective and subjective analysis showed the opposite results regarding image quality because of higher noise levels and artefacts. (orig.)

  15. Strategy of image-information-guided dose rate adjustment in digital X-ray television

    International Nuclear Information System (INIS)

    Sliva, K.

    1992-01-01

    The experiments were so designed and carried out that it was even possible for extremely overexposed or underexposed displays to be ascertained within the framework of this study. They were based on observations in phantoms suitable to simulate situations encountered in actual practice. These permitted variations in patient volume (using different water volumes) just as well as the creation of any desired organ constellation (by insertion of bone material, etc.). It is one requirement of this experimental procedure that the X-ray unit used can be operated without automatic dose rate adjustment. A computer equipped with Frame-Grabber card may serve as an image memory. (orig.) [de

  16. Printable organometallic perovskite enables large-area, low-dose X-ray imaging

    Science.gov (United States)

    Kim, Yong Churl; Kim, Kwang Hee; Son, Dae-Yong; Jeong, Dong-Nyuk; Seo, Ja-Young; Choi, Yeong Suk; Han, In Taek; Lee, Sang Yoon; Park, Nam-Gyu

    2017-10-01

    Medical X-ray imaging procedures require digital flat detectors operating at low doses to reduce radiation health risks. Solution-processed organic-inorganic hybrid perovskites have characteristics that make them good candidates for the photoconductive layer of such sensitive detectors. However, such detectors have not yet been built on thin-film transistor arrays because it has been difficult to prepare thick perovskite films (more than a few hundred micrometres) over large areas (a detector is typically 50 centimetres by 50 centimetres). We report here an all-solution-based (in contrast to conventional vacuum processing) synthetic route to producing printable polycrystalline perovskites with sharply faceted large grains having morphologies and optoelectronic properties comparable to those of single crystals. High sensitivities of up to 11 microcoulombs per air KERMA of milligray per square centimetre (μC mGyair-1 cm-2) are achieved under irradiation with a 100-kilovolt bremsstrahlung source, which are at least one order of magnitude higher than the sensitivities achieved with currently used amorphous selenium or thallium-doped cesium iodide detectors. We demonstrate X-ray imaging in a conventional thin-film transistor substrate by embedding an 830-micrometre-thick perovskite film and an additional two interlayers of polymer/perovskite composites to provide conformal interfaces between perovskite films and electrodes that control dark currents and temporal charge carrier transportation. Such an all-solution-based perovskite detector could enable low-dose X-ray imaging, and could also be used in photoconductive devices for radiation imaging, sensing and energy harvesting.

  17. Printable organometallic perovskite enables large-area, low-dose X-ray imaging.

    Science.gov (United States)

    Kim, Yong Churl; Kim, Kwang Hee; Son, Dae-Yong; Jeong, Dong-Nyuk; Seo, Ja-Young; Choi, Yeong Suk; Han, In Taek; Lee, Sang Yoon; Park, Nam-Gyu

    2017-10-04

    Medical X-ray imaging procedures require digital flat detectors operating at low doses to reduce radiation health risks. Solution-processed organic-inorganic hybrid perovskites have characteristics that make them good candidates for the photoconductive layer of such sensitive detectors. However, such detectors have not yet been built on thin-film transistor arrays because it has been difficult to prepare thick perovskite films (more than a few hundred micrometres) over large areas (a detector is typically 50 centimetres by 50 centimetres). We report here an all-solution-based (in contrast to conventional vacuum processing) synthetic route to producing printable polycrystalline perovskites with sharply faceted large grains having morphologies and optoelectronic properties comparable to those of single crystals. High sensitivities of up to 11 microcoulombs per air KERMA of milligray per square centimetre (μC mGy air -1 cm -2 ) are achieved under irradiation with a 100-kilovolt bremsstrahlung source, which are at least one order of magnitude higher than the sensitivities achieved with currently used amorphous selenium or thallium-doped cesium iodide detectors. We demonstrate X-ray imaging in a conventional thin-film transistor substrate by embedding an 830-micrometre-thick perovskite film and an additional two interlayers of polymer/perovskite composites to provide conformal interfaces between perovskite films and electrodes that control dark currents and temporal charge carrier transportation. Such an all-solution-based perovskite detector could enable low-dose X-ray imaging, and could also be used in photoconductive devices for radiation imaging, sensing and energy harvesting.

  18. Experimental validation of a kilovoltage x-ray source model for computing imaging dose

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, Yannick, E-mail: yannick.poirier@cancercare.mb.ca [CancerCare Manitoba, 675 McDermot Ave, Winnipeg, Manitoba R3E 0V9 (Canada); Kouznetsov, Alexei; Koger, Brandon [Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Tambasco, Mauro, E-mail: mtambasco@mail.sdsu.edu [Department of Physics, San Diego State University, San Diego, California 92182-1233 and Department of Physics and Astronomy and Department of Oncology, University of Calgary, Calgary, Alberta T2N 1N4 (Canada)

    2014-04-15

    Purpose: To introduce and validate a kilovoltage (kV) x-ray source model and characterization method to compute absorbed dose accrued from kV x-rays. Methods: The authors propose a simplified virtual point source model and characterization method for a kV x-ray source. The source is modeled by: (1) characterizing the spatial spectral and fluence distributions of the photons at a plane at the isocenter, and (2) creating a virtual point source from which photons are generated to yield the derived spatial spectral and fluence distribution at isocenter of an imaging system. The spatial photon distribution is determined by in-air relative dose measurements along the transverse (x) and radial (y) directions. The spectrum is characterized using transverse axis half-value layer measurements and the nominal peak potential (kVp). This source modeling approach is used to characterize a Varian{sup ®} on-board-imager (OBI{sup ®}) for four default cone-beam CT beam qualities: beams using a half bowtie filter (HBT) with 110 and 125 kVp, and a full bowtie filter (FBT) with 100 and 125 kVp. The source model and characterization method was validated by comparing dose computed by the authors’ inhouse software (kVDoseCalc) to relative dose measurements in a homogeneous and a heterogeneous block phantom comprised of tissue, bone, and lung-equivalent materials. Results: The characterized beam qualities and spatial photon distributions are comparable to reported values in the literature. Agreement between computed and measured percent depth-dose curves is ⩽2% in the homogeneous block phantom and ⩽2.5% in the heterogeneous block phantom. Transverse axis profiles taken at depths of 2 and 6 cm in the homogeneous block phantom show an agreement within 4%. All transverse axis dose profiles in water, in bone, and lung-equivalent materials for beams using a HBT, have an agreement within 5%. Measured profiles of FBT beams in bone and lung-equivalent materials were higher than their

  19. Empirical electro-optical and x-ray performance evaluation of CMOS active pixels sensor for low dose, high resolution x-ray medical imaging

    International Nuclear Information System (INIS)

    Arvanitis, C. D.; Bohndiek, S. E.; Royle, G.; Blue, A.; Liang, H. X.; Clark, A.; Prydderch, M.; Turchetta, R.; Speller, R.

    2007-01-01

    Monolithic complementary metal oxide semiconductor (CMOS) active pixel sensors with high performance have gained attention in the last few years in many scientific and space applications. In order to evaluate the increasing capabilities of this technology, in particular where low dose high resolution x-ray medical imaging is required, critical electro-optical and physical x-ray performance evaluation was determined. The electro-optical performance includes read noise, full well capacity, interacting quantum efficiency, and pixels cross talk. The x-ray performance, including x-ray sensitivity, modulation transfer function, noise power spectrum, and detection quantum efficiency, has been evaluated in the mammographic energy range. The sensor is a 525x525 standard three transistor CMOS active pixel sensor array with more than 75% fill factor and 25x25 μm pixel pitch. Reading at 10 f/s, it is found that the sensor has 114 electrons total additive noise, 10 5 electrons full well capacity with shot noise limited operation, and 34% interacting quantum efficiency at 530 nm. Two different structured CsI:Tl phosphors with thickness 95 and 115 μm, respectively, have been optically coupled via a fiber optic plate to the array resulting in two different system configurations. The sensitivity of the two different system configurations was 43 and 47 electrons per x-ray incident on the sensor. The MTF at 10% of the two different system configurations was 9.5 and 9 cycles/mm with detective quantum efficiency of 0.45 and 0.48, respectively, close to zero frequency at ∼0.44 μC/kg (1.72 mR) detector entrance exposure. The detector was quantum limited at low spatial frequencies and its performance was comparable with high resolution a:Si and charge coupled device based x-ray imagers. The detector also demonstrates almost an order of magnitude lower noise than active matrix flat panel imagers. The results suggest that CMOS active pixel sensors when coupled to structured CsI:Tl can

  20. Low Dose X-Ray Sources and High Quantum Efficiency Sensors: The Next Challenge in Dental Digital Imaging?

    Directory of Open Access Journals (Sweden)

    Arnav R. Mistry

    2014-01-01

    Full Text Available Objective(s. The major challenge encountered to decrease the milliamperes (mA level in X-ray imaging systems is the quantum noise phenomena. This investigation evaluated dose exposure and image resolution of a low dose X-ray imaging (LDXI prototype comprising a low mA X-ray source and a novel microlens-based sensor relative to current imaging technologies. Study Design. A LDXI in static (group 1 and dynamic (group 2 modes was compared to medical fluoroscopy (group 3, digital intraoral radiography (group 4, and CBCT scan (group 5 using a dental phantom. Results. The Mann-Whitney test showed no statistical significance (α=0.01 in dose exposure between groups 1 and 3 and 1 and 4 and timing exposure (seconds between groups 1 and 5 and 2 and 3. Image resolution test showed group 1 > group 4 > group 2 > group 3 > group 5. Conclusions. The LDXI proved the concept for obtaining a high definition image resolution for static and dynamic radiography at lower or similar dose exposure and smaller pixel size, respectively, when compared to current imaging technologies. Lower mA at the X-ray source and high QE at the detector level principles with microlens could be applied to current imaging technologies to considerably reduce dose exposure without compromising image resolution in the near future.

  1. Traditional x-ray imaging

    International Nuclear Information System (INIS)

    Hay, G.A.

    1982-01-01

    Methods of imaging x-rays, with particular reference to medicine, are reviewed. The history and nature of x-rays, their production and spectra, contrast, shapes and fine structure, image transducers, including fluorescent screens, radiography, fluoroscopy, and image intensifiers, image detection, perception and enhancement and clinical applications are considered. (U.K.)

  2. Dose Matters: FDA's Guidance on Children's X-rays

    Science.gov (United States)

    ... Consumer Updates Dose Matters: FDA's Guidance on Children's X-rays Share Tweet Linkedin Pin it More sharing options ... exposure during medical procedures. The level of ionizing radiation from X-ray imaging is generally very low, but can ...

  3. X-ray diagnostic installation with an image intensifier TV chain and a dose rate control device

    Energy Technology Data Exchange (ETDEWEB)

    Duemmling, K; Schott, O

    1977-04-28

    The person performing the examination can key up the dose rate briefly via the X-ray tube current, e.g., if the movement of a contrast medium is to be observed on the video screen and only certain phases in this movement, which are of diagnostic significance, are to be viewed more closely. The upward change necessary to reduce quantum noise by a certain factor is made by means of a switch. This at the same time results in a reduction of brightness (over-exposure) of the X-ray image on the video screen by actuating an aperture system between the image intensifier, and the TV camera. To prevent the X-ray tube from being overloaded during key-up of the dose rate, a time limit switch is installed in the control system.

  4. X-raying with low dose irradiation

    International Nuclear Information System (INIS)

    Malevich, E.E.; Kisel, E.M.; Shpita, I.D.; Lazovsky, A.S.

    2001-01-01

    With the purpose of the improvement of diagnostics quality and reduction of beam load on a patient in modern x-ray devices pulse x-raying is applied. It is based on the using of radiation pulses with various frequencies of intervals between them instead of continuous radiation. At pulse x-raying with the net control the principle of filling of an interval is used, when the information about the image, received with the last pulse, get into memory and is displayed before occurrence of other pulse. It creates impression of the continuous image even at low frequency of pulses. Due to the unique concept of the simultaneous (double) control, all of 3 parameters, which define the quality of the image (pressure(voltage), force of a current and length of a pulse), are adjusted automatically at each pulse, thus optimum adaptation to varied thickness of object during dynamic researches occurs. At x-raying pulse the presence of a free interval from x-ray radiation between two pulses results in the decrease of a radiation dose. Pulsing occurs some times per one second with equal intervals between pulses. Thus, the degree of decrease irradiation dose depends on duration of a pause between pulses. On the screen the image of last pulse before occurrence of the following is kept and repeats. The principle of x-raying pulse was realized in system Grid Controlled Fluoroscopy by the firm 'Philips Medi zin Systeme'. In the x-ray tube of this system inclusion and de energizing of radiation occurs directly on a source. Electron cloud is broken off by the special grid, which is located between the cathode and the anode and operates as a barrier. Thus the tube continues to be energized. In usual devices for pulses formation is used generator pulsation system, which at increase and attenuation of a x-ray pulse results in occurrence of the increasing and fading radiation which are not participating in the formation of the image, but creating beam load on the patient and the personnel. Thus

  5. Measurement and monitoring of entrance exposure dose rate in X-ray image intensifier television with dose rate control

    Energy Technology Data Exchange (ETDEWEB)

    Klein, J [Bezirkskrankenhaus Brandenburg (German Democratic Republic)

    1981-03-01

    For X-ray image intensifier television operation very low entrance dose rates (about 5.2 nA/kg) are stated and demanded, respectively. These required values are often manifold exceeded in practice so that a check seems to be necessary. It is shown and proved how these measurements can be performed with simple, generally available means of measurement in the radiological practice. For ZnCdS-image intensifiers should be considered that about 13 nA/kg for the large entrance size are not to be exceeded; for the CsI type lower values (factor 1.5) are practicable because of the twofold quantum absorption efficiency. Furthermore, some tests for a semiquantitative function check of the automatic dose rate control are proposed.

  6. X-ray imaging system

    International Nuclear Information System (INIS)

    Houston, J.M.

    1980-01-01

    A novel, high-speed apparatus for use in X-ray computerised tomography is described in detail. It consists of a semi-circular array of X-ray sources, collimators and an ion chamber array for detection of the X-rays. The X-ray sources may be pulsed in salvos such that the corresponding detectors in the array are only illuminated by one source. The use of computer controlled salvos speeds up the image processing by at least a factor of two. The ion chamber array is designed to have a constant detection efficiency for varying angles of X-ray incidence. A detailed description of the detector construction and suggested gaseous fillings are given. It is claimed that the present tomographic system allows fast and accurate imaging of internal body organs and is insensitive to the blurring effects which motion of these organs tends to produce. (UK)

  7. X-ray image intensifier photography

    International Nuclear Information System (INIS)

    Richter, K.; Angerstein, W.; Steinhardt, L.

    1980-01-01

    The present treatise on X-ray image intensifier photography starts with introductory remarks on the history of X-ray imaging and image intensifiers. In the physical-technological part especially the quality of image and the methods of its measurement are discussed in detail. The relevant equipment such as image intensifier cameras, X-ray television, video recorder and devices of display and evaluation of images are presented as well as problems of radiation doses and radiation protection. Based on 25,000 examinations of the digestive, the biliary and the urinary tract, resp., as well as of the blood vessels the applicability of the X-ray image intensifier photography and its diagnostic value are demonstrated in the medical part of the book

  8. Dose evaluation for digital X-ray imaging of premature neonates

    International Nuclear Information System (INIS)

    Minkels, T.J.M.; Jeukens, C.R.L.P.N.; Andriessen, P.; Van der Linden, A.N.; Dam, A.J.; Van Straaten, H.L.M.; Cottaar, E.J.E.; Van Pul, C.

    2017-01-01

    X-ray radiography is a commonly used diagnostic method for premature neonates. However, because of higher radiosensitivity and young age, premature neonates are more sensitive to the detrimental effects of ionising radiation. Therefore, it is important to monitor and optimise radiation doses at the neonatal intensive care unit (NICU). The number of X-ray examinations, dose area product (DAP) and effective doses are evaluated for three Dutch NICUs using digital flat panel detectors. Thorax, thorax abdomen and abdomen protocols are included in this study. Median number of examinations is equal to 1 for all three hospitals. Median DAP ranges between 0.05 and 1.02 μGy m2 for different examination types and different weight categories. These examinations result in mean effective doses between 4 ± 4 and 30 ± 10 μSv per examination. Substantial differences in protocols and doses can be observed between hospitals. This emphasises the need for up-to-date reference levels formulated specifically for premature neonates. (authors)

  9. SU-E-J-23: Characteristics of X-Rays From ExacTrac and Patient Dose From Imaging Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Ding, G [Vanderbilt University, Nashville, TN (United States)

    2015-06-15

    Purpose: The purpose of this investigation is 1) provide the beam characteristics of x-rays produced by a Novalis TX ExacTrac system; 2) present a method to commission such beams, 3) present radiation dose to patients resulting from the imaging procedures. Methods: The Monte Carlo simulations were used to obtain the characteristics of kV beams and validated by measurements. The calculated beam HVLs, profiles and depth-dose curves were benchmarked against measurements. Twelve different image acquisition protocols were studied. The x-ray tube voltage ranges from 70 - 145 kV and milliampere-second (mAs) ranges from 8 - 80 mAs depending on the selection of Cranium, Head & Neck, Thorax or Abdomen imaging protocols. The beam output of each image acquisition protocol was determined by using an ionization chamber. The air kerma calibration factors of the ion chamber were obtained from an Accredited Dosimetry Calibration Laboratory for specified HVLs. Results: The agreements between measured and simulated results were within the uncertainties for HVLs, dose profiles and depth-dose curves. When %dd was normalized at 1 cm depth, its values at depth of 5 cm ranged from 45% to 66% of in water for kV beams range from 70 kVp to 145 kVp respectively. For head images, a typical dose to eye resulting from single projection ranged from 0.008 cGy to 0.025 cGy depending on the cranial image protocols selected. For a single pelvic image the skin dose could reach up to 0.1 cGy from an abdominal protocol. Conclusion: Although multiple pairs of x-ray images are commonly acquired during a daily patient treatment, the imaging doses to patients resulting from the sum of these projected x-rays are generally much less than 0.5 cGy. The knowledge obtained from this investigation can be used to estimate the image dose and optimize the used of the system.

  10. A feasibility study for image guided radiotherapy using low dose, high speed, cone beam X-ray volumetric imaging

    International Nuclear Information System (INIS)

    Sykes, Jonathan R.; Amer, Ali; Czajka, Jadwiga; Moore, Christopher J.

    2005-01-01

    Background and purpose: Image Guidance of patient set-up for radiotherapy can be achieved by acquiring X-ray volumetric images (XVI) with Elekta Synergy and registering these to the planning CT scan. This enables full 3D registration of structures from similar 3D imaging modalities and offers superior image quality, rotational set-up information and a large field of view. This study uses the head section of the Rando phantom to demonstrate a new paradigm of faster, lower dose XVI that still allows registration to high precision. Materials and methods: One high exposure XVI scan and one low exposure XVI scan were performed with a Rando Head Phantom. The second scan was used to simulate ultra low dose, fast acquisition, full and half scans by discarding a large number of projections before reconstruction. Dose measurements were performed using Thermo Luminescent Dosimeters (TLD) and an ion chamber. The reconstructed XVI scans were automatically registered with a helical CT scan of the Rando Head using the volumetric, grey-level, cross-correlation algorithm implemented in the Syntegra software package (Philips Medical Systems). Reproducibility of the registration process was investigated. Results: In both XVI scans the body surface, bone-tissue and tissue air interfaces were clearly visible. Although the subjective image quality of the low dose cone beam scan was reduced, registration of both cone beam scans with the planning CT scan agreed within 0.1 mm and 0.1 deg. Dose to the patient was reduced from 28 mGy to less than 1 mGy and the equivalent scan speed reduced to one minute or less. Conclusions: Automatic 3D registration of high speed, ultra low dose XVI scans with the planning CT scan can be used for precision 3D patient set-up verification/image guidance on a daily basis with out loss of accuracy when compared to higher dose XVI scans

  11. X-ray image coding

    International Nuclear Information System (INIS)

    1974-01-01

    The invention aims at decreasing the effect of stray radiation in X-ray images. This is achieved by putting a plate between source and object with parallel zones of alternating high and low absorption coefficients for X-radiation. The image is scanned with the help of electronic circuits which decode the signal space coded by the plate, thus removing the stray radiation

  12. Radiation dose measurements of an on-board imager X-ray unit using optically-stimulated luminescence dosimeters

    International Nuclear Information System (INIS)

    Smith, Leon; Haque, Mamoon; Hill, Robin; Morales, Johnny

    2015-01-01

    Cone beam computed tomography (CBCT) is now widely used to image radiotherapy patients prior to treatment for the purpose of accurate patient setup. However each CBCT image delivered to a patient increases the total radiation dose that they receive. The measurement of the dose delivered from the CBCT images is not readily performed in the clinic. In this study, we have used commercially available optically stimulated luminescence (OSLD) dosimeters to measure the dose delivered by the Varian OBI on a radiotherapy linear accelerator. Calibration of the OSLDs was achieved by using a therapeutic X-ray unit. The dose delivered by a head CBCT scan was found to be 3.2 ± 0.3 mGy which is similar in magnitude to the dose of a head computed tomography (CT) scan. The results of this study suggest that the radiation hazard associated with CBCT is of a similar nature to that of conventional CT scans. We have also demonstrated that the OSLDs are suitable for these low X-ray dose measurements.

  13. Effects of X-Ray Dose On Rhizosphere Studies Using X-Ray Computed Tomography

    Science.gov (United States)

    Zappala, Susan; Helliwell, Jonathan R.; Tracy, Saoirse R.; Mairhofer, Stefan; Sturrock, Craig J.; Pridmore, Tony; Bennett, Malcolm; Mooney, Sacha J.

    2013-01-01

    X-ray Computed Tomography (CT) is a non-destructive imaging technique originally designed for diagnostic medicine, which was adopted for rhizosphere and soil science applications in the early 1980s. X-ray CT enables researchers to simultaneously visualise and quantify the heterogeneous soil matrix of mineral grains, organic matter, air-filled pores and water-filled pores. Additionally, X-ray CT allows visualisation of plant roots in situ without the need for traditional invasive methods such as root washing. However, one routinely unreported aspect of X-ray CT is the potential effect of X-ray dose on the soil-borne microorganisms and plants in rhizosphere investigations. Here we aimed to i) highlight the need for more consistent reporting of X-ray CT parameters for dose to sample, ii) to provide an overview of previously reported impacts of X-rays on soil microorganisms and plant roots and iii) present new data investigating the response of plant roots and microbial communities to X-ray exposure. Fewer than 5% of the 126 publications included in the literature review contained sufficient information to calculate dose and only 2.4% of the publications explicitly state an estimate of dose received by each sample. We conducted a study involving rice roots growing in soil, observing no significant difference between the numbers of root tips, root volume and total root length in scanned versus unscanned samples. In parallel, a soil microbe experiment scanning samples over a total of 24 weeks observed no significant difference between the scanned and unscanned microbial biomass values. We conclude from the literature review and our own experiments that X-ray CT does not impact plant growth or soil microbial populations when employing a low level of dose (<30 Gy). However, the call for higher throughput X-ray CT means that doses that biological samples receive are likely to increase and thus should be closely monitored. PMID:23840640

  14. Dose distribution in lungs and thyroid from scatter photons of x-ray mammography imaging

    International Nuclear Information System (INIS)

    Faghihi, R.; Mehdizadeh, S.

    2006-01-01

    The contribution of scatter photons in dose of mammography image in thyroid and lungs are studied. Thyroid and in the form of distribution function and total delivered dose studied by direct measurement with Thermoluminescence dosimeter. The results of measurements compared to other published measurements and the total dose compared to our modelling with Monte Carlo method.. Our phantoms for direct measurement of Dose are a compressed breast phantom placed on a female RANDO phantom. The results of modelling and measurement are in agreement for the total delivered dose to thyroid and lungs and comparable to doses reported by the other researcher

  15. Poisson–Gaussian Noise Analysis and Estimation for Low-Dose X-ray Images in the NSCT Domain

    Science.gov (United States)

    Lee, Sangyoon; Lee, Min Seok; Kang, Moon Gi

    2018-01-01

    The noise distribution of images obtained by X-ray sensors in low-dosage situations can be analyzed using the Poisson and Gaussian mixture model. Multiscale conversion is one of the most popular noise reduction methods used in recent years. Estimation of the noise distribution of each subband in the multiscale domain is the most important factor in performing noise reduction, with non-subsampled contourlet transform (NSCT) representing an effective method for scale and direction decomposition. In this study, we use artificially generated noise to analyze and estimate the Poisson–Gaussian noise of low-dose X-ray images in the NSCT domain. The noise distribution of the subband coefficients is analyzed using the noiseless low-band coefficients and the variance of the noisy subband coefficients. The noise-after-transform also follows a Poisson–Gaussian distribution, and the relationship between the noise parameters of the subband and the full-band image is identified. We then analyze noise of actual images to validate the theoretical analysis. Comparison of the proposed noise estimation method with an existing noise reduction method confirms that the proposed method outperforms traditional methods. PMID:29596335

  16. Poisson-Gaussian Noise Analysis and Estimation for Low-Dose X-ray Images in the NSCT Domain.

    Science.gov (United States)

    Lee, Sangyoon; Lee, Min Seok; Kang, Moon Gi

    2018-03-29

    The noise distribution of images obtained by X-ray sensors in low-dosage situations can be analyzed using the Poisson and Gaussian mixture model. Multiscale conversion is one of the most popular noise reduction methods used in recent years. Estimation of the noise distribution of each subband in the multiscale domain is the most important factor in performing noise reduction, with non-subsampled contourlet transform (NSCT) representing an effective method for scale and direction decomposition. In this study, we use artificially generated noise to analyze and estimate the Poisson-Gaussian noise of low-dose X-ray images in the NSCT domain. The noise distribution of the subband coefficients is analyzed using the noiseless low-band coefficients and the variance of the noisy subband coefficients. The noise-after-transform also follows a Poisson-Gaussian distribution, and the relationship between the noise parameters of the subband and the full-band image is identified. We then analyze noise of actual images to validate the theoretical analysis. Comparison of the proposed noise estimation method with an existing noise reduction method confirms that the proposed method outperforms traditional methods.

  17. High Energy Resolution Hyperspectral X-Ray Imaging for Low-Dose Contrast-Enhanced Digital Mammography.

    Science.gov (United States)

    Pani, Silvia; Saifuddin, Sarene C; Ferreira, Filipa I M; Henthorn, Nicholas; Seller, Paul; Sellin, Paul J; Stratmann, Philipp; Veale, Matthew C; Wilson, Matthew D; Cernik, Robert J

    2017-09-01

    Contrast-enhanced digital mammography (CEDM) is an alternative to conventional X-ray mammography for imaging dense breasts. However, conventional approaches to CEDM require a double exposure of the patient, implying higher dose, and risk of incorrect image registration due to motion artifacts. A novel approach is presented, based on hyperspectral imaging, where a detector combining positional and high-resolution spectral information (in this case based on Cadmium Telluride) is used. This allows simultaneous acquisition of the two images required for CEDM. The approach was tested on a custom breast-equivalent phantom containing iodinated contrast agent (Niopam 150®). Two algorithms were used to obtain images of the contrast agent distribution: K-edge subtraction (KES), providing images of the distribution of the contrast agent with the background structures removed, and a dual-energy (DE) algorithm, providing an iodine-equivalent image and a water-equivalent image. The high energy resolution of the detector allowed the selection of two close-by energies, maximising the signal in KES images, and enhancing the visibility of details with the low surface concentration of contrast agent. DE performed consistently better than KES in terms of contrast-to-noise ratio of the details; moreover, it allowed a correct reconstruction of the surface concentration of the contrast agent in the iodine image. Comparison with CEDM with a conventional detector proved the superior performance of hyperspectral CEDM in terms of the image quality/dose tradeoff.

  18. Radiation dose to neonates undergoing X-ray imaging in special care baby units in Iran

    International Nuclear Information System (INIS)

    Faghihi, R.; Mehdizadeh, S.; Sina, S.; Alizadeh, F. N.; Zeinali, B.; Kamyab, G. R.; Aghevlian, S.; Khorramdel, H.; Namazi, I.; Heirani, M.; Moshkriz, M.; Mahani, H.; Sharifzadeh, M.

    2012-01-01

    Radiographic imaging has a significant role in the timely diagnosis of the diseases of neonates in intensive care units. The estimation of the dose received by the infants undergoing radiographic examination is of great importance, due to greater more radiosensitivity and longer life expectancy of the neonates and premature babies. In this study, the values of entrance skin dose (ESD), dose area products (DAPs), energy imparted (EI), whole-body dose, effective dose and risk of childhood cancer were estimated using three methods including direct method [using thermoluminescence dosimetry (TLD) chips], indirect method (using tube output) and Monte Carlo (MC) method (using MCNP4C code). In the first step, the ESD of the neonates was directly measured using TLD-100 chips. Fifty neonates, mostly premature, with different weights and gestational ages in five hospitals mostly suffering from respiratory distress syndrome and pneumonia were involved in this study. In the second step, the values of ESD to neonates were indirectly obtained from the tube output in different imaging techniques. The imaging room, incubator, neonates and other components were then simulated in order to obtain the ESD values using the MCNP4C code. Finally, the values of ESD assessed by the three methods were used for calculation of DAP, EI, whole-body dose, effective dose and risk of childhood cancer. The results indicate that the mean ESD per radiograph estimated by the direct, indirect and MC methods are 56.6±4.1, 50.1±3.1 and 54.5±3.3 μGy, respectively. The mean risk of childhood cancer estimated in this study varied between 4.21x10 -7 and 2.72x10 -6 . (authors)

  19. Improved spatial resolution and lower-dose pediatric CT imaging: a feasibility study to evaluate narrowing the X-ray photon energy spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Benz, Mark G. [Safer Pediatric Imaging and Engineering Horizons International, Lincoln, VT (United States); Benz, Matthew W. [Southboro Medical Group, Southboro, MA (United States); Birnbaum, Steven B. [Dartmouth Hitchcock Clinic Manchester, Department of Radiology, Manchester, NH (United States); Chason, Eric; Sheldon, Brian W. [Brown University, Division of Engineering, Materials Science and Engineering Program, Providence, RI (United States); McGuire, Dale [R and D Manager, C and G Technologies Inc., Jeffersonville, IN (United States)

    2014-08-15

    This feasibility study has shown that improved spatial resolution and reduced radiation dose can be achieved in pediatric CT by narrowing the X-ray photon energy spectrum. This is done by placing a hafnium filter between the X-ray generator and a pediatric abdominal phantom. A CT system manufactured in 1999 that was in the process of being remanufactured was used as the platform for this study. This system had the advantage of easy access to the X-ray generator for modifications to change the X-ray photon energy spectrum; it also had the disadvantage of not employing the latest post-imaging noise reduction iterative reconstruction technology. Because we observed improvements after changing the X-ray photon energy spectrum, we recommend a future study combining this change with an optimized iterative reconstruction noise reduction technique. (orig.)

  20. Assessing image quality and dose reduction of a new x-ray computed tomography iterative reconstruction algorithm using model observers

    International Nuclear Information System (INIS)

    Tseng, Hsin-Wu; Kupinski, Matthew A.; Fan, Jiahua; Sainath, Paavana; Hsieh, Jiang

    2014-01-01

    Purpose: A number of different techniques have been developed to reduce radiation dose in x-ray computed tomography (CT) imaging. In this paper, the authors will compare task-based measures of image quality of CT images reconstructed by two algorithms: conventional filtered back projection (FBP), and a new iterative reconstruction algorithm (IR). Methods: To assess image quality, the authors used the performance of a channelized Hotelling observer acting on reconstructed image slices. The selected channels are dense difference Gaussian channels (DDOG).A body phantom and a head phantom were imaged 50 times at different dose levels to obtain the data needed to assess image quality. The phantoms consisted of uniform backgrounds with low contrast signals embedded at various locations. The tasks the observer model performed included (1) detection of a signal of known location and shape, and (2) detection and localization of a signal of known shape. The employed DDOG channels are based on the response of the human visual system. Performance was assessed using the areas under ROC curves and areas under localization ROC curves. Results: For signal known exactly (SKE) and location unknown/signal shape known tasks with circular signals of different sizes and contrasts, the authors’ task-based measures showed that a FBP equivalent image quality can be achieved at lower dose levels using the IR algorithm. For the SKE case, the range of dose reduction is 50%–67% (head phantom) and 68%–82% (body phantom). For the study of location unknown/signal shape known, the dose reduction range can be reached at 67%–75% for head phantom and 67%–77% for body phantom case. These results suggest that the IR images at lower dose settings can reach the same image quality when compared to full dose conventional FBP images. Conclusions: The work presented provides an objective way to quantitatively assess the image quality of a newly introduced CT IR algorithm. The performance of the

  1. Soft x-ray Planetary Imager

    Data.gov (United States)

    National Aeronautics and Space Administration — The project is to prototype a soft X-ray Imager for planetary applications that has the sensitivity to observe solar system sources of soft  X-ray emission. A strong...

  2. Antero-posterior (AP) pelvis x-ray imaging on a trolley: Impact of trolley design, mattress design and radiographer practice on image quality and radiation dose

    International Nuclear Information System (INIS)

    Tugwell, J.R.; England, A.; Hogg, P.

    2017-01-01

    Introduction: Physical and technical differences exist between imaging on an x-ray tabletop and imaging on a trolley. This study evaluates how trolley imaging impacts image quality and radiation dose for an antero-posterior (AP) pelvis projection whilst subsequently exploring means of optimising this imaging examination. Methods: An anthropomorphic pelvis phantom was imaged on a commercially available trolley under various conditions. Variables explored included two mattresses, two image receptor holder positions, three source to image distances (SIDs) and four mAs values. Image quality was evaluated using relative visual grading analysis with the reference image acquired on the x-ray tabletop. Contrast to noise ratio (CNR) was calculated. Effective dose was established using Monte Carlo simulation. Optimisation scores were derived as a figure of merit by dividing effective dose with visual image quality scores. Results: Visual image quality reduced significantly (p < 0.05) whilst effective dose increased significantly (p < 0.05) for images acquired on the trolley using identical acquisition parameters to the reference image. The trolley image with the highest optimisation score was acquired using 130 cm SID, 20 mAs, the standard mattress and platform not elevated. A difference of 12.8 mm was found between the image with the lowest and highest magnification factor (18%). Conclusion: The acquisition parameters used for AP pelvis on the x-ray tabletop are not transferable to trolley imaging and should be modified accordingly to compensate for the differences that exist. Exposure charts should be developed for trolley imaging to ensure optimal image quality at lowest possible dose. - Highlights: • Acquisition parameters used for AP pelvis imaging on a trolley need adapting from those used on the x-ray tabletop. • Radiation dose significantly increases for trolley imaging. • An increase in SID can reduce radiation dose and magnification for trolley imaging

  3. Adaptive-weighted total variation minimization for sparse data toward low-dose x-ray computed tomography image reconstruction.

    Science.gov (United States)

    Liu, Yan; Ma, Jianhua; Fan, Yi; Liang, Zhengrong

    2012-12-07

    Previous studies have shown that by minimizing the total variation (TV) of the to-be-estimated image with some data and other constraints, piecewise-smooth x-ray computed tomography (CT) can be reconstructed from sparse-view projection data without introducing notable artifacts. However, due to the piecewise constant assumption for the image, a conventional TV minimization algorithm often suffers from over-smoothness on the edges of the resulting image. To mitigate this drawback, we present an adaptive-weighted TV (AwTV) minimization algorithm in this paper. The presented AwTV model is derived by considering the anisotropic edge property among neighboring image voxels, where the associated weights are expressed as an exponential function and can be adaptively adjusted by the local image-intensity gradient for the purpose of preserving the edge details. Inspired by the previously reported TV-POCS (projection onto convex sets) implementation, a similar AwTV-POCS implementation was developed to minimize the AwTV subject to data and other constraints for the purpose of sparse-view low-dose CT image reconstruction. To evaluate the presented AwTV-POCS algorithm, both qualitative and quantitative studies were performed by computer simulations and phantom experiments. The results show that the presented AwTV-POCS algorithm can yield images with several notable gains, in terms of noise-resolution tradeoff plots and full-width at half-maximum values, as compared to the corresponding conventional TV-POCS algorithm.

  4. Evaluation of patient dose in imaging using a cone-beam CT dosimetry by X-ray films for radiotherapeutic dose

    International Nuclear Information System (INIS)

    Yoshida, Yuri; Morita, Yasuhiko; Honda, Eiichi; Tomotake, Yoritoki; Ichikawa, Tetsuo

    2008-01-01

    A limited cone-beam X-ray CT (3DX multi-image micro CT; 3DX-FPD) is widely used in dentistry because it provides a lower cost, smaller size, and higher spatial resolution than a CT for medicine. Our recent research suggested that the patient dose of 3DX-FPD was less than 7/10 of that of CT, and it was several to 10 times more than that of dental or panoramic radiography. The purpose of this study was to evaluate the spatial dose distribution from 3DX-FPD and to estimate the influence of dose by positioning of the region of interest. Dosimetry of the organs and the tissues was performed using an anthropomorphic Alderson Rando phantom and X-ray films for measurement of radiotherapeutic dose. Measurements of dose distribution were performed using a cylinder-type tank of water made of acrylic resin imitating the head and X-ray films. The results are summarized as follows: The dose was higher as the ratio of the air region included in the region of interest increased. The dose distribution was not homogeneous and the dose was highest in the skin region. The dose was higher for several seconds after the beginning of exposure. It was concluded that patient positioning, as well as exposure conditions including the size of the exposure field and tube current, could greatly influence the patient dose in 3DX-FPD. In addition, it is necessary to consider the influence of image quality for the treatment of dental implants. (author)

  5. Phase-contrast X-ray imaging using an X-ray interferometer for biological imaging

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi; Koyama, Ichiro [Tokyo Univ., Dept. of Applied Physics, Tokyo (Japan); Takeda, Tohoru; Itai, Yuji [Tsukuba Univ., Inst. of Clinical Medicine, Tsukuba, Ibaraki (Japan); Yoneyama, Akio [Hitachi Ltd., Advanced Research Laboratory, Saitama (Japan)

    2002-04-01

    The potential of phase-contrast X-ray imaging using an X-ray interferometer is discussed comparing with other phase-contrast X-ray imaging methods, and its principle of contrast generation is presented including the case of phase-contrast X-ray computed tomography. The status of current instrumentation is described and perspectives for practical applications are discussed. (author)

  6. Entrance surface dose and image quality: Comparison of adult chest and abdominal X-ray examinations in general practitioner clinics, public and private hospitals in Malaysia

    International Nuclear Information System (INIS)

    Hambali, A. S.; Ng, K. H.; Abdullah, B. J. J.; Wang, H. B.; Jamal, N.; Spelic, D. C.; Suleiman, O. H.

    2009-01-01

    This study was undertaken to compare the entrance surface dose (ESD) and image quality of adult chest and abdominal X-ray examinations conducted at general practitioner (GP) clinics, and public and private hospitals in Malaysia. The surveyed facilities were randomly selected within a given category (28 GP clinics, 20 public hospitals and 15 private hospitals). Only departmental X-ray units were involved in the survey. Chest examinations were done at all facilities, while only hospitals performed abdominal examinations. This study used the x-ray attenuation phantoms and protocols developed for the Nationwide Evaluation of X-ray Trends (NEXT) survey program in the United States. The ESD was calculated from measurements of exposure and clinical geometry. An image quality test tool was used to evaluate the low-contrast detectability and high-contrast detail performance under typical clinical conditions. The median ESD value for the adult chest X-ray examination was the highest (0.25 mGy) at GP clinics, followed by private hospitals (0.22 mGy) and public hospitals (0.17 mGy). The median ESD for the adult abdominal X-ray examination at public hospitals (3.35 mGy) was higher than that for private hospitals (2.81 mGy). Results of image quality assessment for the chest X-ray examination show that all facility types have a similar median spatial resolution and low-contrast detectability. For the abdominal X-ray examination, public hospitals have a similar median spatial resolution but larger low-contrast detectability compared with private hospitals. The results of this survey clearly show that there is room for further improvement in performing chest and abdominal X-ray examinations in Malaysia. (authors)

  7. Combining Acceleration Techniques for Low-Dose X-Ray Cone Beam Computed Tomography Image Reconstruction.

    Science.gov (United States)

    Huang, Hsuan-Ming; Hsiao, Ing-Tsung

    2017-01-01

    Over the past decade, image quality in low-dose computed tomography has been greatly improved by various compressive sensing- (CS-) based reconstruction methods. However, these methods have some disadvantages including high computational cost and slow convergence rate. Many different speed-up techniques for CS-based reconstruction algorithms have been developed. The purpose of this paper is to propose a fast reconstruction framework that combines a CS-based reconstruction algorithm with several speed-up techniques. First, total difference minimization (TDM) was implemented using the soft-threshold filtering (STF). Second, we combined TDM-STF with the ordered subsets transmission (OSTR) algorithm for accelerating the convergence. To further speed up the convergence of the proposed method, we applied the power factor and the fast iterative shrinkage thresholding algorithm to OSTR and TDM-STF, respectively. Results obtained from simulation and phantom studies showed that many speed-up techniques could be combined to greatly improve the convergence speed of a CS-based reconstruction algorithm. More importantly, the increased computation time (≤10%) was minor as compared to the acceleration provided by the proposed method. In this paper, we have presented a CS-based reconstruction framework that combines several acceleration techniques. Both simulation and phantom studies provide evidence that the proposed method has the potential to satisfy the requirement of fast image reconstruction in practical CT.

  8. Dose levels in conventional X-rays

    International Nuclear Information System (INIS)

    Guerra M, J. A.; Gonzalez G, J. A.; Pinedo S, A.; Salas L, M. A.; Vega C, H. R.; Rivera M, T.; Azorin N, J.

    2009-10-01

    There were a series of measures in the General Hospital of Fresnillo in the X-ray Department in the areas of X-1 and X-2-ray rooms and in the neonatal intensive care unit 2, was determined the dose surface entry in eyes, thyroid and gonads for patients undergoing to X-ray study of chest Tele by thermoluminescent dosimetry. Five dosemeters were used in each one of the scans; so find the following dose ranges 20 + - 23 mGy to 350 + - 41 mGy. With the results obtained we can conclude that the procedures used and the equipment calibration is adequate. (Author)

  9. Impact of digital imaging on radiation doses to the patient during X-ray examination of the urinary tract.

    Science.gov (United States)

    Sjöholm, B; Geijer, H; Persliden, J

    2005-10-01

    To compare radiation doses given to patients undergoing IVU (intravenous urography) before and after digitalization of our X-ray department. IVU examinations were monitored with dose area product meters before and after the X-ray department changed to digital techniques. The first step was a change from film-screen to storage phosphor plates, while the second step involved changing to a flat panel detector. Forty-two patients were included for the film-screen situation, 69 when using the storage phosphor plates, and 70 using the flat panel detector. A dose reduction from 41.8 Gycm2 to 31.5 Gycm2 was achieved with the first step when the film-screen system was replaced with storage phosphor plates. A further reduction to 12.1 Gycm2 was achieved using the flat panel detector. The introduction of the flat panel detectors made a considerable dose reduction possible.

  10. X-ray image intensifier tube

    International Nuclear Information System (INIS)

    1981-01-01

    An improved real-time x-ray image intensifier tube of the proximity type used for medical x-ray fluoroscopy is described. It is claimed that this intensifier is of sufficient gain and resolution whilst remaining convenient to use and that the design is such that the patient dosage is minimized whilst the x-ray image information content at the scintillator-photocathode screen is maximized. (U.K.)

  11. Differences of X-ray exposure between X-ray diagnostics with a conventional X-ray screen-system and with an image-intensifier-television-unit

    International Nuclear Information System (INIS)

    Loehr, H.; Vogel, H.; Reinhart, J.; Jantzen, R.

    1977-01-01

    During X-ray diagnostics of patients in the II. Medizinische Poliklinik the X-ray exposure was determined. It corresponded to the data described in literature. Two groups were compared: 518 patients examined with a conventional X-ray screen-system and 642 patients examined with an image-intensifier-television-system. The results demonstrated that with exception of thoracical X-ray examination the replacing of the old system by the television system brought a remarkable increase of the X-ray exposure. The doses depended of the patients constitution to a high degree. (orig.) [de

  12. Quality guarantee of images as a way for obtained lower levels of radiation doses in diagnostic x-ray rooms: criteria for licensing

    International Nuclear Information System (INIS)

    Castellanos, C.A.

    1996-01-01

    This work constitutes a criticism to the present system for licensing in diagnostic x-ray installations in Guatemala. A series of recommendations are made with the aim of obtaining the best diagnostic imaging. This procedure leads to obtain lower doses of radiation for patients and workers

  13. Image analysis in x-ray cinefluorography

    Energy Technology Data Exchange (ETDEWEB)

    Ikuse, J; Yasuhara, H; Sugimoto, H [Toshiba Corp., Kawasaki, Kanagawa (Japan)

    1979-02-01

    For the cinefluorographic image in the cardiovascular diagnostic system, the image quality is evaluated by means of MTF (Modulation Transfer Function), and object contrast by introducing the concept of x-ray spectrum analysis. On the basis of these results, further investigation is made of optimum X-ray exposure factors set for cinefluorography and the cardiovascular diagnostic system.

  14. Medical imaging: Material change for X-ray detectors

    Science.gov (United States)

    Rowlands, John A.

    2017-10-01

    The X-ray sensitivity of radiology instruments is limited by the materials used in their detectors. A material from the perovskite family of semiconductors could allow lower doses of X-rays to be used for medical imaging. See Letter p.87

  15. Body packers on your examination table: How helpful are plain x-ray images? A definitive low-dose CT protocol as a diagnosis tool for body packers.

    Science.gov (United States)

    Schulz, B; Grossbach, A; Gruber-Rouh, T; Zangos, S; Vogl, Th J; Eichler, K

    2014-12-01

    To analyze the clinical value and radiation dose of plain x-rays and CT in examining patients suspected of ingesting drug-filled packets. Thirty-eight patients with suspected internal concealment of drug-filled packets who were examined with plain x-rays or CT or both were included in the study. CT studies were performed using low-dose and standard-dose techniques. All radiographic images were analysed by two radiologists regarding identification of the packets and estimating the effective radiation dose from standard- and low-dose CT versus conventional x-ray examinations. Descriptive calculations were made regarding the number and density of packs and radiation dosage. The diagnostic performance of both radiologists with standard- and low-dose CT was calculated by analysing differences in the mean number of packs found. Thirty-one patients were positively identified as body packers with an average of 13 packs (min: n = 1, max: n = 58, total: n = 390); seven patients were not concealing drug packets. X-ray images were taken of 24 patients prior to CT, thus allowing a direct comparison between the two methods. The correct diagnosis was made in 42%, in 33% the radiologists were uncertain, and in 25% of drug packets were either not or wrongly identified. X-ray imaging had a positive predictive value of 20% with a negative predictive value of 81%. A total of 55 CT examinations were performed on all patients with a mean effective dose of 2 mSv (low dose) versus 9.3 mSv (standard dose). The visibility of packets on low-dose CT images compared to high-dose CT was not reduced: the radiologists identified 385 and 381 of the packets, respectively, with no difference regarding the examination technique (p = 0.24 and p = 0.253, respectively). The radiodensity of all drug-filled packets at CT ranged from 26-292 HU (mean 181.2 HU). X-ray imaging of supposed body packers leads to a significant risk of diagnostic errors and additional need for CT. Instead, a single abdominal low-dose

  16. Radiation dose and image quality of X-ray volume imaging systems: cone-beam computed tomography, digital subtraction angiography and digital fluoroscopy.

    Science.gov (United States)

    Paul, Jijo; Jacobi, Volkmar; Farhang, Mohammad; Bazrafshan, Babak; Vogl, Thomas J; Mbalisike, Emmanuel C

    2013-06-01

    Radiation dose and image quality estimation of three X-ray volume imaging (XVI) systems. A total of 126 patients were examined using three XVI systems (groups 1-3) and their data were retrospectively analysed from 2007 to 2012. Each group consisted of 42 patients and each patient was examined using cone-beam computed tomography (CBCT), digital subtraction angiography (DSA) and digital fluoroscopy (DF). Dose parameters such as dose-area product (DAP), skin entry dose (SED) and image quality parameters such as Hounsfield unit (HU), noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were estimated and compared using appropriate statistical tests. Mean DAP and SED were lower in recent XVI than its previous counterparts in CBCT, DSA and DF. HU of all measured locations was non-significant between the groups except the hepatic artery. Noise showed significant difference among groups (P < 0.05). Regarding CNR and SNR, the recent XVI showed a higher and significant difference compared to its previous versions. Qualitatively, CBCT showed significance between versions unlike the DSA and DF which showed non-significance. A reduction of radiation dose was obtained for the recent-generation XVI system in CBCT, DSA and DF. Image noise was significantly lower; SNR and CNR were higher than in previous versions. The technological advancements and the reduction in the number of frames led to a significant dose reduction and improved image quality with the recent-generation XVI system. • X-ray volume imaging (XVI) systems are increasingly used for interventional radiological procedures. • More modern XVI systems use lower radiation doses compared with earlier counterparts. • Furthermore more modern XVI systems provide higher image quality. • Technological advances reduce radiation dose and improve image quality.

  17. Visual grading analysis of digital neonatal chest phantom X-ray images: Impact of detector type, dose and image processing on image quality.

    Science.gov (United States)

    Smet, M H; Breysem, L; Mussen, E; Bosmans, H; Marshall, N W; Cockmartin, L

    2018-07-01

    To evaluate the impact of digital detector, dose level and post-processing on neonatal chest phantom X-ray image quality (IQ). A neonatal phantom was imaged using four different detectors: a CR powder phosphor (PIP), a CR needle phosphor (NIP) and two wireless CsI DR detectors (DXD and DRX). Five different dose levels were studied for each detector and two post-processing algorithms evaluated for each vendor. Three paediatric radiologists scored the images using European quality criteria plus additional questions on vascular lines, noise and disease simulation. Visual grading characteristics and ordinal regression statistics were used to evaluate the effect of detector type, post-processing and dose on VGA score (VGAS). No significant differences were found between the NIP, DXD and CRX detectors (p>0.05) whereas the PIP detector had significantly lower VGAS (pProcessing did not influence VGAS (p=0.819). Increasing dose resulted in significantly higher VGAS (plevels but not image post-processing changes. VGA showed a DAK/image value above which perceived IQ did not improve, potentially useful for commissioning. • A VGA study detects IQ differences between detectors and dose levels. • The NIP detector matched the VGAS of the CsI DR detectors. • VGA data are useful in setting initial detector air kerma level. • Differences in NNPS were consistent with changes in VGAS.

  18. Imaging X-ray astronomy

    International Nuclear Information System (INIS)

    Elvis, M.

    1990-01-01

    The launch of the High Energy Astrophysical Observatory, more appealingly called the Einstein Observatory, marked one of the most revolutionary steps taken in astrophysics this century. Its greater sensitivity compared with earlier satellites and its ability to make high spacial and spectral resolution observations transformed X-ray astronomy. This book is based on a Symposium held in Cambridge, Massachusetts, to celebrate a decade of Einstein Observatory's achievements. It discusses the contributions that this satellite has made to each area of modern astrophysics and the diversity of the ongoing work based on Einstein data. There is a guide to each of the main data bases now coming on-line to increase the availability and to preserve this valuable archive for the future. A review of NASA's next big X-ray mission, AXAF, and a visionary program for novel X-ray astronomy satellites by Riccardo Giacconi conclude this wide-ranging volume. (author)

  19. SU-E-J-06: Additional Imaging Guidance Dose to Patient Organs Resulting From X-Ray Tubes Used in CyberKnife Image Guidance System

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, A; Ding, G [Vanderbilt University, Nashville, TN (United States)

    2015-06-15

    Purpose: The use of image-guided radiation therapy (IGRT) has become increasingly common, but the additional radiation exposure resulting from repeated image guidance procedures raises concerns. Although there are many studies reporting imaging dose from different image guidance devices, imaging dose for the CyberKnife Robotic Radiosurgery System is not available. This study provides estimated organ doses resulting from image guidance procedures on the CyberKnife system. Methods: Commercially available Monte Carlo software, PCXMC, was used to calculate average organ doses resulting from x-ray tubes used in the CyberKnife system. There are seven imaging protocols with kVp ranging from 60 – 120 kV and 15 mAs for treatment sites in the Cranium, Head and Neck, Thorax, and Abdomen. The output of each image protocol was measured at treatment isocenter. For each site and protocol, Adult body sizes ranging from anorexic to extremely obese were simulated since organ dose depends on patient size. Doses for all organs within the imaging field-of-view of each site were calculated for a single image acquisition from both of the orthogonal x-ray tubes. Results: Average organ doses were <1.0 mGy for every treatment site and imaging protocol. For a given organ, dose increases as kV increases or body size decreases. Higher doses are typically reported for skeletal components, such as the skull, ribs, or clavicles, than for softtissue organs. Typical organ doses due to a single exposure are estimated as 0.23 mGy to the brain, 0.29 mGy to the heart, 0.08 mGy to the kidneys, etc., depending on the imaging protocol and site. Conclusion: The organ doses vary with treatment site, imaging protocol and patient size. Although the organ dose from a single image acquisition resulting from two orthogonal beams is generally insignificant, the sum of repeated image acquisitions (>100) could reach 10–20 cGy for a typical treatment fraction.

  20. Effects of X-rays spectrum on the dose

    International Nuclear Information System (INIS)

    Rodriguez I, J. L.; Hernandez A, P. L.; Vega C, H. R.; Rivera M, T.

    2015-10-01

    The X-ray equipment for diagnosis comes in different sizes and shapes depending on the scan type to perform. The X-ray spectrum is the energy distribution of the beam photons and consists of a continuous spectrum of photons braking and discrete spectrum due to the characteristic photons. The knowledge of the X-rays spectrum is important to understand like they affect the voltage changes (k Vp), current (m A), time (s) and the type of filter in the interaction mechanisms between X-rays and patient's body, the image receptor or other material that gets in the beam. Across the spectrum can be estimated the absorbed dose in any point of the patient, the quality of the image and the scattered radiation (which is related to the dose received by the equipment operator). The Monte Carlo method was used by MCNP5 code to calculate the spectrum of X-rays that occurs when a monoenergetic electron beam of 250 keV interact with targets of Mo, Rh and W. The spectra were calculated with and without filter, and the values of ambient dose equivalent were estimated, as well as the air kerma. (Author)

  1. Impact of Digital Imaging on Radiation Doses to the Patient During X-ray Examination of the Urinary Tract

    International Nuclear Information System (INIS)

    Sjoeholm, B.; Geijer, H.; Persliden, J.

    2005-01-01

    Purpose: To compare radiation doses given to patients undergoing IVU (intravenous urography) before and after digitalization of our X-ray department. Material and Methods: IVU examinations were monitored with dose area product meters before and after the X-ray department changed to digital techniques. The first step was a change from film-screen to storage phosphor plates, while the second step involved changing to a flat panel detector. Forty-two patients were included for the film-screen situation, 69 when using the storage phosphor plates, and 70 using the flat panel detector. Results: A dose reduction from 41.8 Gycm 2 to 31.5 Gycm 2 was achieved with the first step when the film-screen system was replaced with storage phosphor plates. A further reduction to 12.1 Gycm 2 was achieved using the flat panel detector. Conclusion: The introduction of the flat panel detectors made a considerable dose reduction possible Digital radiography, dosimetry, urinary

  2. Impact of Digital Imaging on Radiation Doses to the Patient During X-ray Examination of the Urinary Tract

    Energy Technology Data Exchange (ETDEWEB)

    Sjoeholm, B. [Oerebro Univ. Hospital (Sweden). Depts. of Medical Physics and Radiology; Geijer, H. [Oerebro Univ. (Sweden). Dept. of Physics; Persliden, J. [Linkoeping Univ. (Sweden). Dept. of Radiation Physics

    2005-10-01

    Purpose: To compare radiation doses given to patients undergoing IVU (intravenous urography) before and after digitalization of our X-ray department. Material and Methods: IVU examinations were monitored with dose area product meters before and after the X-ray department changed to digital techniques. The first step was a change from film-screen to storage phosphor plates, while the second step involved changing to a flat panel detector. Forty-two patients were included for the film-screen situation, 69 when using the storage phosphor plates, and 70 using the flat panel detector. Results: A dose reduction from 41.8 Gycm{sup 2} to 31.5 Gycm{sup 2} was achieved with the first step when the film-screen system was replaced with storage phosphor plates. A further reduction to 12.1 Gycm{sup 2} was achieved using the flat panel detector. Conclusion: The introduction of the flat panel detectors made a considerable dose reduction possible Digital radiography, dosimetry, urinary.

  3. SU-D-207-07: Implementation of Full/half Bowtie Filter Model in a Commercial Treatment Planning System for Kilovoltage X-Ray Imaging Dose Estimation

    International Nuclear Information System (INIS)

    Kim, S; Alaei, P

    2015-01-01

    Purpose: To implement full/half bowtie filter models in a commercial treatment planning system (TPS) to calculate kilovoltage (kV) x-ray imaging dose of Varian On-Board Imager (OBI) cone beam CT (CBCT) system. Methods: Full/half bowtie filters of Varian OBI were created as compensator models in Pinnacle TPS (version 9.6) using Matlab software (version 2011a). The profiles of both bowtie filters were acquired from the manufacturer, imported into the Matlab system and hard coded in binary file format. A Pinnacle script was written to import each bowtie filter data into a Pinnacle treatment plan as a compensator. A kV x-ray beam model without including the compensator model was commissioned per each bowtie filter setting based on percent depth dose and lateral profile data acquired from Monte Carlo simulations. To validate the bowtie filter models, a rectangular water phantom was generated in the planning system and an anterior/posterior beam with each bowtie filter was created. Using the Pinnacle script, each bowtie filter compensator was added to the treatment plan. Lateral profile at the depth of 3cm and percent depth dose were measured using an ion chamber and compared with the data extracted from the treatment plans. Results: The kV x-ray beams for both full and half bowtie filter have been modeled in a commercial TPS. The difference of lateral and depth dose profiles between dose calculations and ion chamber measurements were within 6%. Conclusion: Both full/half bowtie filter models provide reasonable results in kV x-ray dose calculations in the water phantom. This study demonstrates the possibility of using a model-based treatment planning system to calculate the kV imaging dose for both full and half bowtie filter modes. Further study is to be performed to evaluate the models in clinical situations

  4. Radiation doses and image quality in pediatric chest X-ray for the diagnosis of pneumonia in selected Latin American countries

    International Nuclear Information System (INIS)

    Jimenez, P.; Fleitas, I.; Cotelo, E.; Estevan, M.

    2008-01-01

    Full text: Pneumonia and acute lower respiratory infections in general, is the leading cause of child death in developing countries. According to the World Health Organization (WHO), 4 millions of children die annually due to this disease. Despite the growing use of vaccination as an alternate approach to reduce mortality, the increasing antimicrobial resistance and the high costs of vaccines remain important obstacles in the global struggle against the disease. The usual treatment strategy begins with a clinical examination of the patient followed by the prescription of a chest X-ray. Radiography would appear as the best available method for diagnosing pneumonia only if radiologists (and other health professionals such as pediatricians) knew how to interpret the images showed in the radiographs, and these meeting the standards of quality (anatomic structures, image contrast and optical density, and patient dose among other factors). On the other hand, special attention should be paid on patient doses due to children's specific radiosensitivity, repeated and extended use of chest x-ray in all Radiology Departments, and high rejection rate due to both equipment malfunction and to human skills shortcomings. Patient doses of chest X-ray performed to children less than 5 years old in PAHO Sentinel Hospitals for surveillance of bacterial pneumonias in various Latin American countries were estimated using technical parameters and equipment specifications. Image quality was compared to WHO criteria for chest X-rays quality. Results showing differences in patient doses translates on one hand the impact of specific characteristics of the radiological equipment, including equipment limitations and performance of the radiographs and on the other various and divers levels of health professionals skills and training on image quality interpretation and dose optimization. The study concludes that professionals' training and education on chest radiographs image quality constitutes

  5. The X-ray imager on AXO

    DEFF Research Database (Denmark)

    Budtz-Jørgensen, Carl; Kuvvetli, Irfan; Westergaard, Niels Jørgen Stenfeldt

    2001-01-01

    DSRI has initiated a development program of CZT X-ray and gamma-ray detectors employing strip readout techniques. A dramatic improvement of the energy response was found operating the detectors as the so-called drift detectors. For the electronic readout, modern ASIC chips were investigated....... Modular design and the low-power electronics will make large area detectors using the drift strip method feasible. The performance of a prototype CZT system will be presented and discussed. One such detector system has been proposed for future space missions: the X-Ray Imager (XRI) on the Atmospheric X-ray...... Observatory (AXO), which is a mission proposed to the Danish Small Satellite Program and is dedicated to observations of X-ray generating processes in the Earth's atmosphere. Of special interest will be simultaneous optical and X-ray observations of sprites that are flashes appearing directly above an active...

  6. A Computer Program Method for Estimation of Entrance Skin Dose for some Individuals Undergoing X-ray Imaging

    International Nuclear Information System (INIS)

    Taha, T.M.; Allehyani, S.

    2012-01-01

    A computer program depends on practical measurements of entrance skin dose patients undergoing radiological examinations. Physical parameters such as field size, half value layer, backscatter factor, dose output, focal film distance, focal skin distance, normal operating conditions were taken into consideration for calculation entrance skin dose. It was measured by many techniques such as Thermo-luminescence dosimeters, ionization chambers. TLD technique characterized by high precision and reproducibility of dose measurement is checked by addressing pre-readout annealing, group sorting, dose evaluation, Fifty TLD chips were annealed for 1 hour at 400 degree C followed by 2 h at 100 degree C. After exposure to constant dose from X-ray generator. 0.6 cc Ionization chamber was located at surface of water chest phantom that has dimensions of 40 cm x 40 cm x 20 cm and connected with farmer dose master. Entrance Skin Dose was calculated using the generated software by changing the physical parameters and using the measured output doses. The obtained results were compared with the reference levels of International Atomic Energy Authority. The constructed computer program provides an easy and more practical mean of estimating skin dose even before exposure. They also provide the easiest and cheapest technique can be employed in any entrance skin dose measurement

  7. Digital X-ray Imaging in Dentistry

    International Nuclear Information System (INIS)

    Kim, Eun Kyung

    1999-01-01

    In dentistry, Radio Visio Graphy was introduced as a first electronic dental x-ray imaging modality in 1989. Thereafter, many types of direct digital radiographic systems have been produced in the last decade. They are based either on charge-coupled device (CCD) or on storage phosphor technology. In addition, new types of digital radiographic system using amorphous selenium, image intensifier etc. are under development. Advantages of digital radiographic system are elimination of chemical processing, reduction in radiation dose, image processing, computer storage, electronic transfer of images and so on. Image processing includes image enhancement, image reconstruction, digital subtraction, etc. Especially digital subtraction and reconstruction can be applied in many aspects of clinical practice and research. Electronic transfer of images enables filmless dental hospital and teleradiology/teledentistry system. Since the first image management and communications system (IMACS) for dentomaxillofacial radiology was reported in 1992, IMACS in dental hospital has been increasing. Meanwhile, researches about computer-assisted diagnosis, such as structural analysis of bone trabecular patterns of mandible, feature extraction, automated identification of normal landmarks on cephalometric radiograph and automated image analysis for caries or periodontitis, have been performed actively in the last decade. Further developments in digital radiographic imaging modalities, image transmission system, imaging processing and automated analysis software will change the traditional clinical dental practice in the 21st century.

  8. Digital X-ray Imaging in Dentistry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Kyung [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Dankook University, Yongin (Korea, Republic of)

    1999-08-15

    In dentistry, Radio Visio Graphy was introduced as a first electronic dental x-ray imaging modality in 1989. Thereafter, many types of direct digital radiographic systems have been produced in the last decade. They are based either on charge-coupled device (CCD) or on storage phosphor technology. In addition, new types of digital radiographic system using amorphous selenium, image intensifier etc. are under development. Advantages of digital radiographic system are elimination of chemical processing, reduction in radiation dose, image processing, computer storage, electronic transfer of images and so on. Image processing includes image enhancement, image reconstruction, digital subtraction, etc. Especially digital subtraction and reconstruction can be applied in many aspects of clinical practice and research. Electronic transfer of images enables filmless dental hospital and teleradiology/teledentistry system. Since the first image management and communications system (IMACS) for dentomaxillofacial radiology was reported in 1992, IMACS in dental hospital has been increasing. Meanwhile, researches about computer-assisted diagnosis, such as structural analysis of bone trabecular patterns of mandible, feature extraction, automated identification of normal landmarks on cephalometric radiograph and automated image analysis for caries or periodontitis, have been performed actively in the last decade. Further developments in digital radiographic imaging modalities, image transmission system, imaging processing and automated analysis software will change the traditional clinical dental practice in the 21st century.

  9. Evaluation of TLD dose response compared to MCNP-5 simulation of diagnostic X ray equipment - radiation diagnostic image

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez G, R.; Cavalieri, T. A.; De Paiva, F.; Dalledone S, P. de T.; Yoriyaz, H. [Instituto de Pesquisas Energeticas e Nucleares, Centro de Engenharia Nuclear / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil); Rodrigues F, M. A. [Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, Departamento de Dermatologia e Radioterapia, Av. Prof. Montenegro s/n, Rubiao Junior, 18601-970 Botucatu (Brazil); Vivolo, V., E-mail: chancez@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares, Gerencia de Metrologia das Radiacoes / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil)

    2014-08-15

    The thermo luminescent dosimeter (TLD) is used as a radiation dosimeter and can be used as environmental and staff personnel monitoring. The TLD measures ionizing radiation exposure by a process in which the amount of radiation collected by the dosimeter is converted in visible light when the crystal is heated. The amount of emitted light is proportional to the radiation exposure, and then the response of the TLD must be the related to the real dose. In this work it was used twenty four TLD 700 in order to obtain eight values of doses from a diagnostic X-ray equipment. The TLD-700 is a LiF TLD enriched with {sup 7}Li isotope. One way to compare and study the response of TLD is by Monte Carlo method, which has been used as a computational tool to solve problems stochastically. This method can be applied to any geometry, even those where the boundary conditions are unknown, making the method particularly useful to solve problems a priori. In this work it was modeled the X-ray tube exactly as the one used to irradiate the TLD, after the simulation and the TLD irradiation the results of dose value from both were compared. (Author)

  10. Evaluation of TLD dose response compared to MCNP-5 simulation of diagnostic X ray equipment - radiation diagnostic image

    International Nuclear Information System (INIS)

    Sanchez G, R.; Cavalieri, T. A.; De Paiva, F.; Dalledone S, P. de T.; Yoriyaz, H.; Rodrigues F, M. A.; Vivolo, V.

    2014-08-01

    The thermo luminescent dosimeter (TLD) is used as a radiation dosimeter and can be used as environmental and staff personnel monitoring. The TLD measures ionizing radiation exposure by a process in which the amount of radiation collected by the dosimeter is converted in visible light when the crystal is heated. The amount of emitted light is proportional to the radiation exposure, and then the response of the TLD must be the related to the real dose. In this work it was used twenty four TLD 700 in order to obtain eight values of doses from a diagnostic X-ray equipment. The TLD-700 is a LiF TLD enriched with 7 Li isotope. One way to compare and study the response of TLD is by Monte Carlo method, which has been used as a computational tool to solve problems stochastically. This method can be applied to any geometry, even those where the boundary conditions are unknown, making the method particularly useful to solve problems a priori. In this work it was modeled the X-ray tube exactly as the one used to irradiate the TLD, after the simulation and the TLD irradiation the results of dose value from both were compared. (Author)

  11. X-ray imaging: Status and trends

    International Nuclear Information System (INIS)

    Ryon, R.W.; Martz, H.E.; Hernandez, J.M.; Haskins, J.J.; Day, R.A.; Brase, J.M.; Cross, B.; Wherry, D.

    1987-08-01

    There is a veritable renaissance occurring in x-ray imaging. X-ray imaging by radiography has been a highly developed technology in medicine and industry for many years. However, high resolution imaging has not generally been practical because sources have been relatively dim and diffuse, optical elements have been nonexistent for most applications, and detectors have been slow and of low resolution. Materials analysis needs have therefore gone unmet. Rapid progress is now taking place because we are able to exploit developments in microelectronics and related material fabrication techniques, and because of the availability of intense x-ray sources. This report describes the methods and uses of x-ray imaging along with a discussion of technology advances in these areas

  12. X-ray phase-contrast imaging

    Science.gov (United States)

    Endrizzi, Marco

    2018-01-01

    X-ray imaging is a standard tool for the non-destructive inspection of the internal structure of samples. It finds application in a vast diversity of fields: medicine, biology, many engineering disciplines, palaeontology and earth sciences are just few examples. The fundamental principle underpinning the image formation have remained the same for over a century: the X-rays traversing the sample are subjected to different amount of absorption in different parts of the sample. By means of phase-sensitive techniques it is possible to generate contrast also in relation to the phase shifts imparted by the sample and to extend the capabilities of X-ray imaging to those details that lack enough absorption contrast to be visualised in conventional radiography. A general overview of X-ray phase contrast imaging techniques is presented in this review, along with more recent advances in this fast evolving field and some examples of applications.

  13. Body packers on your examination table: How helpful are plain x-ray images? A definitive low-dose CT protocol as a diagnosis tool for body packers

    International Nuclear Information System (INIS)

    Schulz, B.; Grossbach, A.; Gruber-Rouh, T.; Zangos, S.; Vogl, Th. J.; Eichler, K.

    2014-01-01

    Aim: To analyze the clinical value and radiation dose of plain x-rays and CT in examining patients suspected of ingesting drug-filled packets. Materials and methods: Thirty-eight patients with suspected internal concealment of drug-filled packets who were examined with plain x-rays or CT or both were included in the study. CT studies were performed using low-dose and standard-dose techniques. All radiographic images were analysed by two radiologists regarding identification of the packets and estimating the effective radiation dose from standard- and low-dose CT versus conventional x-ray examinations. Descriptive calculations were made regarding the number and density of packs and radiation dosage. The diagnostic performance of both radiologists with standard- and low-dose CT was calculated by analysing differences in the mean number of packs found. Results: Thirty-one patients were positively identified as body packers with an average of 13 packs (min: n = 1, max: n = 58, total: n = 390); seven patients were not concealing drug packets. X-ray images were taken of 24 patients prior to CT, thus allowing a direct comparison between the two methods. The correct diagnosis was made in 42%, in 33% the radiologists were uncertain, and in 25% of drug packets were either not or wrongly identified. X-ray imaging had a positive predictive value of 20% with a negative predictive value of 81%. A total of 55 CT examinations were performed on all patients with a mean effective dose of 2 mSv (low dose) versus 9.3 mSv (standard dose). The visibility of packets on low-dose CT images compared to high-dose CT was not reduced: the radiologists identified 385 and 381 of the packets, respectively, with no difference regarding the examination technique (p = 0.24 and p = 0.253, respectively). The radiodensity of all drug-filled packets at CT ranged from 26–292 HU (mean 181.2 HU). Conclusion: X-ray imaging of supposed body packers leads to a significant risk of diagnostic

  14. Understanding X-ray cargo imaging

    International Nuclear Information System (INIS)

    Chen Gongyin

    2005-01-01

    Cargo imaging is the field of imaging large objects, usually cargo containers, trains, trucks or boats. Transmission imaging with photons, especially X-rays of up to 9 MV is the dominant current technique, providing compelling details of the contents of objects this large. This paper discusses the physics aspects of a good X-ray cargo imaging system. The basic performance requirements, such as penetration, contrast and resolution and the components of a cargo imaging system are introduced. The imaging process is divided in this paper into three stages: forming information (probing the object), recording information and presenting information (image display). Their impact on performance is analyzed

  15. Diffraction enhanced x-ray imaging

    International Nuclear Information System (INIS)

    Thomlinson, W.; Zhong, Z.; Johnston, R.E.; Sayers, D.

    1997-09-01

    Diffraction enhanced imaging (DEI) is a new x-ray radiographic imaging modality using synchrotron x-rays which produces images of thick absorbing objects that are almost completely free of scatter. They show dramatically improved contrast over standard imaging applied to the same phantoms. The contrast is based not only on attenuation but also the refraction and diffraction properties of the sample. The diffraction component and the apparent absorption component (absorption plus extinction contrast) can each be determined independently. This imaging method may improve the image quality for medical applications such as mammography

  16. High speed gated x-ray imagers

    International Nuclear Information System (INIS)

    Kilkenny, J.D.; Bell, P.; Hanks, R.; Power, G.; Turner, R.E.; Wiedwald, J.

    1988-01-01

    Single and multi-frame gated x-ray images with time-resolution as fast as 150 psec are described. These systems are based on the gating of microchannel plates in a stripline configuration. The gating voltage comes from the avalanche breakdown of reverse biased p-n junction producing high power voltage pulses as short as 70 psec. Results from single and four frame x-ray cameras used on Nova are described. 8 refs., 9 figs

  17. X-ray image subtracting system

    International Nuclear Information System (INIS)

    Wesbey, W.H.; Keyes, G.S.; Georges, J.-P.J.

    1982-01-01

    An X-ray image subtracting system for making low contrast structures in the images more conspicuous is described. An X-ray source projects successive high and low energy X-ray beam pulses through a body and the resultant X-ray images are converted to optical images. Two image pick-up devices such as TV cameras that have synchronously operated shutters receive the alternate images and convert them to corresponding analog video signals. In some embodiments, the analog signals are converted to a matrix of digital pixel signals that are variously processed and subtracted and converted to signals for driving a TV monitor display and analog storage devices. In other embodiments the signals are processed and subtracted in analog form for display. The high and low energy pulses can follow each other immediately so good registration between subtracted images is obtainable even though the anatomy is in motion. The energy levels of the X-ray pulses are chosen to maximize the difference in attenuation between the anatomical structure which is to be subtracted out and that which remains. (author)

  18. Evaluation of variations in absorbed dose and image noise according to patient forms in X-ray computed tomography

    International Nuclear Information System (INIS)

    Matsubara, Kosuke; Tsujii, Hideo; Yamamoto, Tomoyuki; Koshida, Kichiro; Suzuki, Masayuki; Hayakawa, Mayumi

    2005-01-01

    Excessive radiation exposure in pediatric computed tomography (CT) scanning has become a serious problem, and it is difficult to select scan parameters for the scanning of small patients such as children. We investigated differences in absorbed dose and standard deviation (SD) in Hounsfield unit (HU) caused by differences in the form of the subject using a body-type phantom with removable body parts. Using four X-ray CT scanners, measurements were made with values from 50 mAs to 300 mAs, with slices of 50 mAs, using scan protocols that were assumed to perform thorough examinations. The results showed that the mAs values and absorbed doses were almost proportional, and the absorbed doses in the phantom without body parts were about 1.1-2.2-fold higher than those of the phantom with body parts at the same points. The SD values obtained indicated that the absorbed doses in the phantom with body parts were 0.3-0.6 times those of the phantom without body parts when the mAs values used were adjusted so that both SD values were the same. The absorbed doses in various patient forms can be estimated from these results, and they will become critical data for the selection of appropriate scan protocols. (author)

  19. Evaluation of variations in absorbed dose and image noise according to patient forms in X-ray computed tomography.

    Science.gov (United States)

    Matsubara, Kosuke; Koshida, Kichiro; Suzuki, Masayuki; Hayakawa, Mayumi; Tsujii, Hideo; Yamamoto, Tomoyuki

    2005-12-20

    Excessive radiation exposure in pediatric computed tomography (CT) scanning has become a serious problem, and it is difficult to select scan parameters for the scanning of small patients such as children. We investigated differences in absorbed dose and standard deviation (SD) in Hounsfield unit (HU) caused by differences in the form of the subject using a body-type phantom with removable body parts. Using four X-ray CT scanners, measurements were made with values from 50 mAs to 300 mAs, with slices of 50 mAs, using scan protocols that were assumed to perform thorough examinations. The results showed that the mAs values and absorbed doses were almost proportional, and the absorbed doses in the phantom without body parts were about 1.1-2.2-fold higher than those of the phantom with body parts at the same points. The SD values obtained indicated that the absorbed doses in the phantom with body parts were 0.3-0.6 times those of the phantom without body parts when the mAs values used were adjusted so that both SD values were the same. The absorbed doses in various patient forms can be estimated from these results, and they will become critical data for the selection of appropriate scan protocols.

  20. Evaluation of variations in absorbed dose and image noise according to patient forms in X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Matsubara, Kosuke; Tsujii, Hideo; Yamamoto, Tomoyuki [Kanazawa Univ., Hospital, Kanazawa, Ishikawa (Japan); Koshida, Kichiro; Suzuki, Masayuki; Hayakawa, Mayumi [Kanazawa Univ., Graduate School of Medical Sciences, Kanazawa, Ishikawa (Japan)

    2005-12-15

    Excessive radiation exposure in pediatric computed tomography (CT) scanning has become a serious problem, and it is difficult to select scan parameters for the scanning of small patients such as children. We investigated differences in absorbed dose and standard deviation (SD) in Hounsfield unit (HU) caused by differences in the form of the subject using a body-type phantom with removable body parts. Using four X-ray CT scanners, measurements were made with values from 50 mAs to 300 mAs, with slices of 50 mAs, using scan protocols that were assumed to perform thorough examinations. The results showed that the mAs values and absorbed doses were almost proportional, and the absorbed doses in the phantom without body parts were about 1.1-2.2-fold higher than those of the phantom with body parts at the same points. The SD values obtained indicated that the absorbed doses in the phantom with body parts were 0.3-0.6 times those of the phantom without body parts when the mAs values used were adjusted so that both SD values were the same. The absorbed doses in various patient forms can be estimated from these results, and they will become critical data for the selection of appropriate scan protocols. (author)

  1. X-ray imaging with toroidal mirror

    International Nuclear Information System (INIS)

    Aoki, Sadao; Sakayanagi, Yoshimi

    1978-01-01

    X-ray imaging is made with a single toroidal mirror or two successive toroidal mirrors. Geometrical images at the Gaussian image plane are described by the ray trace. Application of a single toroidal mirror to small-angle scattering is presented. (author)

  2. Characteristics of a New X-Ray Imaging System for Interventional Procedures: Improved Image Quality and Reduced Radiation Dose.

    Science.gov (United States)

    Schernthaner, Ruediger E; Haroun, Reham R; Nguyen, Sonny; Duran, Rafael; Sohn, Jae Ho; Sahu, Sonia; Chapiro, Julius; Zhao, Yan; Radaelli, Alessandro; van der Bom, Imramsjah M; Mauti, Maria; Hong, Kelvin; Geschwind, Jean-François H; Lin, MingDe

    2018-03-01

    To compare image quality and radiation exposure between a new angiographic imaging system and the preceding generation system during uterine artery embolization (UAE). In this retrospective, IRB-approved two-arm study, 54 patients with symptomatic uterine fibroids were treated with UAE on two different angiographic imaging systems. The new system includes optimized acquisition parameters and real-time image processing algorithms. Air kerma (AK), dose area product (DAP) and acquisition time for digital fluoroscopy (DF) and digital subtraction angiography (DSA) were recorded. Body mass index was noted as well. DF image quality was assessed objectively by image noise measurements. DSA image quality was rated by two blinded, independent readers on a four-rank scale. Statistical differences were assessed with unpaired t tests and Wilcoxon rank-sum tests. There was no significant difference between the patients treated on the new (n = 36) and the old system (n = 18) regarding age (p = 0.10), BMI (p = 0.18), DF time (p = 0.35) and DSA time (p = 0.17). The new system significantly reduced the cumulative AK and DAP by 64 and 72%, respectively (median 0.58 Gy and 145.9 Gy*cm 2 vs. 1.62 Gy and 526.8 Gy*cm 2 , p < 0.01 for both). Specifically, DAP for DF and DSA decreased by 59% (75.3 vs. 181.9 Gy*cm 2 , p < 0.01) and 78% (67.6 vs. 312.2 Gy*cm 2 , p < 0.01), respectively. The new system achieved a significant decrease in DF image noise (p < 0.01) and a significantly better DSA image quality (p < 0.01). The new angiographic imaging system significantly improved image quality and reduced radiation exposure during UAE procedures.

  3. X-ray imaging with compound refractive lens and microfocus X-ray tube

    OpenAIRE

    Pina, Ladislav; Dudchik, Yury; Jelinek, Vaclav; Sveda, Libor; Marsik, Jiri; Horvath, Martin; Petr, Ondrej

    2008-01-01

    Compound refractive lenses (CRL), consisting of a lot number in-line concave microlenses made of low-Z material were studied. Lenses with focal length 109 mm and 41 mm for 8-keV X-rays, microfocus X-ray tube and X-ray CCD camera were used in experiments. Obtained images show intensity distribution of magnified microfocus X-ray source focal spot. Within the experiments, one lens was also used as an objective lens of the X-ray microscope, where the copper anode X-ray microfocus tube served as a...

  4. Quantitative Phase Imaging Using Hard X Rays

    International Nuclear Information System (INIS)

    Nugent, K.A.; Gureyev, T.E.; Cookson, D.J.; Paganin, D.; Barnea, Z.

    1996-01-01

    The quantitative imaging of a phase object using 16keV xrays is reported. The theoretical basis of the techniques is presented along with its implementation using a synchrotron x-ray source. We find that our phase image is in quantitative agreement with independent measurements of the object. copyright 1996 The American Physical Society

  5. Feasibility study for application of the compressed-sensing framework to interior computed tomography (ICT) for low-dose, high-accurate dental x-ray imaging

    Science.gov (United States)

    Je, U. K.; Cho, H. M.; Cho, H. S.; Park, Y. O.; Park, C. K.; Lim, H. W.; Kim, K. S.; Kim, G. A.; Park, S. Y.; Woo, T. H.; Choi, S. I.

    2016-02-01

    In this paper, we propose a new/next-generation type of CT examinations, the so-called Interior Computed Tomography (ICT), which may presumably lead to dose reduction to the patient outside the target region-of-interest (ROI), in dental x-ray imaging. Here an x-ray beam from each projection position covers only a relatively small ROI containing a target of diagnosis from the examined structure, leading to imaging benefits such as decreasing scatters and system cost as well as reducing imaging dose. We considered the compressed-sensing (CS) framework, rather than common filtered-backprojection (FBP)-based algorithms, for more accurate ICT reconstruction. We implemented a CS-based ICT algorithm and performed a systematic simulation to investigate the imaging characteristics. Simulation conditions of two ROI ratios of 0.28 and 0.14 between the target and the whole phantom sizes and four projection numbers of 360, 180, 90, and 45 were tested. We successfully reconstructed ICT images of substantially high image quality by using the CS framework even with few-view projection data, still preserving sharp edges in the images.

  6. X-ray detectors in medical imaging

    International Nuclear Information System (INIS)

    Spahn, Martin

    2013-01-01

    Healthcare systems are subject to continuous adaptation, following trends such as the change of demographic structures, the rise of life-style related and chronic diseases, and the need for efficient and outcome-oriented procedures. This also influences the design of new imaging systems as well as their components. The applications of X-ray imaging in the medical field are manifold and have led to dedicated modalities supporting specific imaging requirements, for example in computed tomography (CT), radiography, angiography, surgery or mammography, delivering projection or volumetric imaging data. Depending on the clinical needs, some X-ray systems enable diagnostic imaging while others support interventional procedures. X-ray detector design requirements for the different medical applications can vary strongly with respect to size and shape, spatial resolution, frame rates and X-ray flux, among others. Today, integrating X-ray detectors are in common use. They are predominantly based on scintillators (e.g. CsI or Gd 2 O 2 S) and arrays of photodiodes made from crystalline silicon (Si) or amorphous silicon (a-Si) or they employ semiconductors (e.g. Se) with active a-Si readout matrices. Ongoing and future developments of X-ray detectors will include optimization of current state-of-the-art integrating detectors in terms of performance and cost, will enable the usage of large size CMOS-based detectors, and may facilitate photon counting techniques with the potential to further enhance performance characteristics and foster the prospect of new clinical applications

  7. X-ray fluorescence imaging with polycapillary X-ray optics

    International Nuclear Information System (INIS)

    Yonehara, Tasuku; Yamaguchi, Makoto; Tsuji, Kouichi

    2010-01-01

    X-ray fluorescence spectrometry imaging is a powerful tool to provide information about the chemical composition and elemental distribution of a specimen. X-ray fluorescence spectrometry images were conventionally obtained by using a μ-X-ray fluorescence spectrometry spectrometer, which requires scanning a sample. Faster X-ray fluorescence spectrometry imaging would be achieved by eliminating the process of sample scanning. Thus, we developed an X-ray fluorescence spectrometry imaging instrument without sample scanning by using polycapillary X-ray optics, which had energy filter characteristics caused by the energy dependence of the total reflection phenomenon. In the present paper, we show that two independent straight polycapillary X-ray optics could be used as an energy filter of X-rays for X-ray fluorescence. Only low energy X-rays were detected when the angle between the two optical axes was increased slightly. Energy-selective X-ray fluorescence spectrometry images with projection mode were taken by using an X-ray CCD camera equipped with two polycapillary optics. It was shown that Fe Kα (6.40 keV) and Cu Kα (8.04 keV) could be discriminated for Fe and Cu foils.

  8. The Imaging X-ray Polarimetry Explorer (IXPE

    Directory of Open Access Journals (Sweden)

    Martin C. Weisskopf

    Full Text Available The Imaging X-ray Polarimetry Explorer (IXPE expands observation space by simultaneously adding polarization to the array of X-ray source properties currently measured (energy, time, and location. IXPE will thus open new dimensions for understanding how X-ray emission is produced in astrophysical objects, especially in systems under extreme physical conditions. Keywords: X-ray astronomy, X-ray polarimetry, X-ray imaging

  9. Multilayer X-ray imaging systems

    Science.gov (United States)

    Shealy, D. L.; Hoover, R. B.; Gabardi, D. R.

    1986-01-01

    An assessment of the imaging properties of multilayer X-ray imaging systems with spherical surfaces has been made. A ray trace analysis was performed to investigate the effects of using spherical substrates (rather than the conventional paraboloidal/hyperboloidal contours) for doubly reflecting Cassegrain telescopes. These investigations were carried out for mirrors designed to operate at selected soft X-ray/XUV wavelengths that are of significance for studies of the solar corona/transition region from the Stanford/MSFC Rocket X-Ray Telescope. The effects of changes in separation of the primary and secondary elements were also investigated. These theoretical results are presented as well as the results of ray trace studies to establish the resolution and vignetting effects as a function of field angle and system parameters.

  10. Image quality evaluation and patient dose assessment of medical fluoroscopic X-ray systems: A national study

    International Nuclear Information System (INIS)

    Economides, S.; Hourdakis, C. J.; Kalivas, N.; Kalathaki, M.; Simantirakis, G.; Tritakis, P.; Manousaridis, G.; Vogiatzi, S.; Kipouros, P.; Boziari, A.; Kamenopoulou, V.

    2008-01-01

    This study presents the results from a survey conducted by the Greek Atomic Energy Commission (GAEC), during the period 1998-2003, in 530 public and private owned fluoroscopic X-ray systems in Greece. Certain operational parameters for conventional and remote control systems were assessed, according to a quality control protocol developed by GAEC on the basis of the current literature. Public (91.5%) and private (81.5%) owned fluoroscopic units exhibit high-contrast resolution values over 1 lp mm -1 . Moreover, 88.5 and 87.1% of the fluoroscopic units installed in the public and private sector, respectively, present Maximum Patient Entrance Kerma Rate values lower than 100 mGy min -1 . Additionally, 68.3% of the units assessed were found to perform within the acceptance limits. Finally, the third quartile of the Entrance Surface Dose Rate distribution was estimated according to the Dose Reference Level definition and found equal to 35 mGy min -1 . (authors)

  11. Reduction of doses from diagnostic X-ray procedures

    International Nuclear Information System (INIS)

    Gudden, F.; Kuhn, H.

    1992-01-01

    More recent developments in the field of receiver systems for X-rays have made it possible for doses required in X-ray examinations to be gradually reduced to no more than 5% of the radiation patients were exposed to 30 years ago. Despite this fact, the image quality standards necessary to establish even considerably improved. The author suggests to repeat series of measurements carried out in the distant past to be able to make a population-based assessment of the current risk from the effective equivalence dose in one year. In all likelihood, such a survey would prove the quivalence dose to be much lower than the degree of environmental radiation exposure. (orig./DGD) [de

  12. Experimental determination of blurring in x-ray fluoroscopy last image hold due to patient movement and its repercussion to patient doses

    International Nuclear Information System (INIS)

    Guibelalde, E.; Gonzalez, L.; Vano, E.; Fernandez, J.M.; Alberdi, J.; Molinero, A.

    2001-01-01

    Significant dose reduction can be achieved in fluoroscopy and interventional radiology by using the last image hold (LIH). This feature in modern digital fluoroscopy x-ray units usually works with frame or temporal averaging techniques to reduce noise. This image quality works quite well for objects without motion but it could be a serious limitation in presence of motion blur. With an in-house developed robotic device, the authors have experimentally determined the image quality degradation introduced by normal physiological movements (i.e., respiratory and cardiac pulse movements). FAXIL test objects TO.10 and 18FG from Leeds University have been used for spatial resolution limit and threshold contrast detail detectability. Seven X-ray equipment with last image hold features from three different manufacturers were analysed. Although results show that motion blur affects LIH to different extends depending on equipment, magnification, entrance dose and detail size, it can be estimated that, on average for all equipment and analysed conditions, it represents 30% degradation in image quality parameters in comparison with static images. (author)

  13. Wide-area phase-contrast X-ray imaging using large X-ray interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi E-mail: momose@exp.t.u-tokyo.ac.jp; Takeda, Tohoru; Yoneyama, Akio; Koyama, Ichiro; Itai, Yuji

    2001-07-21

    Large X-ray interferometers are developed for phase-contrast X-ray imaging aiming at medical applications. A monolithic X-ray interferometer and a separate one are studied, and currently a 25 mmx20 mm view area can be generated. This paper describes the strategy of our research program and some recent developments.

  14. Wide-area phase-contrast X-ray imaging using large X-ray interferometers

    Science.gov (United States)

    Momose, Atsushi; Takeda, Tohoru; Yoneyama, Akio; Koyama, Ichiro; Itai, Yuji

    2001-07-01

    Large X-ray interferometers are developed for phase-contrast X-ray imaging aiming at medical applications. A monolithic X-ray interferometer and a separate one are studied, and currently a 25 mm×20 mm view area can be generated. This paper describes the strategy of our research program and some recent developments.

  15. Fluorescence imaging of reactive oxygen species by confocal laser scanning microscopy for track analysis of synchrotron X-ray photoelectric nanoradiator dose: X-ray pump-optical probe.

    Science.gov (United States)

    Jeon, Jae Kun; Han, Sung Mi; Kim, Jong Ki

    2016-09-01

    Bursts of emissions of low-energy electrons, including interatomic Coulomb decay electrons and Auger electrons (0-1000 eV), as well as X-ray fluorescence produced by irradiation of large-Z element nanoparticles by either X-ray photons or high-energy ion beams, is referred to as the nanoradiator effect. In therapeutic applications, this effect can damage pathological tissues that selectively take up the nanoparticles. Herein, a new nanoradiator dosimetry method is presented that uses probes for reactive oxygen species (ROS) incorporated into three-dimensional gels, on which macrophages containing iron oxide nanoparticles (IONs) are attached. This method, together with site-specific irradiation of the intracellular nanoparticles from a microbeam of polychromatic synchrotron X-rays (5-14 keV), measures the range and distribution of OH radicals produced by X-ray emission or superoxide anions ({\\rm{O}}_2^-) produced by low-energy electrons. The measurements are based on confocal laser scanning of the fluorescence of the hydroxyl radical probe 2-[6-(4'-amino)phenoxy-3H-xanthen-3-on-9-yl] benzoic acid (APF) or the superoxide probe hydroethidine-dihydroethidium (DHE) that was oxidized by each ROS, enabling tracking of the radiation dose emitted by the nanoradiator. In the range 70 µm below the irradiated cell, ^\\bullet{\\rm{OH}} radicals derived mostly from either incident X-ray or X-ray fluorescence of ION nanoradiators are distributed along the line of depth direction in ROS gel. In contrast, {\\rm{O}}_2^- derived from secondary electron or low-energy electron emission by ION nanoradiators are scattered over the ROS gel. ROS fluorescence due to the ION nanoradiators was observed continuously to a depth of 1.5 mm for both oxidized APF and oxidized DHE with relatively large intensity compared with the fluorescence caused by the ROS produced solely by incident primary X-rays, which was limited to a depth of 600 µm, suggesting dose enhancement as well as more

  16. Digital X-ray imager

    International Nuclear Information System (INIS)

    1998-01-01

    The global objective of this cooperation was to lower the cost and improve the quality of breast health care in the United States. We planned to achieve it by designing a very high performance digital radiography unit for breast surgical specimen radiography in the operating room. These technical goals needed to be achieved at reasonable manufacturing costs to enable MedOptics to achieve high market penetration at a profit. Responsibility for overall project execution rested with MedOptics. MedOptics fabricated and demonstrated hardware, and selected components and handled the overall integration. After completion of this CRADA, MedOptics worked with collaborators to demonstrate clinical performance and utility. Finally, the company marketed the device. LLNL convened a multi-directorate expert panel for an intensive review of MedOptics point design. A written brief of panel conclusions and recommendations was prepared. In addition, LLNL was responsible for: computationally simulating the effects of varying source voltage and filtering (predicting the required dynamic range for the detector); evaluating CsI:Tl, CdWO4 and scintillating glass as image converters; recommending image enhancement algorithms. The LLNL modeling results guided the design and experimental elements of the project. The Laboratory's unique array of sources and detectors was employed to resolve specific technical questions. Our image processing expertise was applied to the selection of enhancement tools for image display

  17. Chest X ray effective doses estimation in computed radiography

    International Nuclear Information System (INIS)

    Abdalla, Esra Abdalrhman Dfaalla

    2013-06-01

    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)

  18. Dose enhancement effects of X ray radiation in bipolar transistors

    International Nuclear Information System (INIS)

    Chen Panxun

    1997-01-01

    The author has presented behaviour degradation and dose enhancement effects of bipolar transistors in X ray irradiation environment. The relative dose enhancement factors of X ray radiation were measured in bipolar transistors by the experiment methods. The mechanism of bipolar device dose enhancement was investigated

  19. Accelerating an Ordered-Subset Low-Dose X-Ray Cone Beam Computed Tomography Image Reconstruction with a Power Factor and Total Variation Minimization.

    Science.gov (United States)

    Huang, Hsuan-Ming; Hsiao, Ing-Tsung

    2016-01-01

    In recent years, there has been increased interest in low-dose X-ray cone beam computed tomography (CBCT) in many fields, including dentistry, guided radiotherapy and small animal imaging. Despite reducing the radiation dose, low-dose CBCT has not gained widespread acceptance in routine clinical practice. In addition to performing more evaluation studies, developing a fast and high-quality reconstruction algorithm is required. In this work, we propose an iterative reconstruction method that accelerates ordered-subsets (OS) reconstruction using a power factor. Furthermore, we combine it with the total-variation (TV) minimization method. Both simulation and phantom studies were conducted to evaluate the performance of the proposed method. Results show that the proposed method can accelerate conventional OS methods, greatly increase the convergence speed in early iterations. Moreover, applying the TV minimization to the power acceleration scheme can further improve the image quality while preserving the fast convergence rate.

  20. Reduction of patient doses in X-ray diagnosis using quality control tests on image and equipment

    International Nuclear Information System (INIS)

    Milu, C.; Tomulescu, V.; Sorescu, Anca; Vladareanu, M.; Olteanu, B.; Enachescu, B.; Zaharia, N.; Lesaru, M.

    1997-01-01

    In the frame of a research program under the contract with the International Atomic Energy Agency (IAEA), several patient dose measurements were performed using thermoluminescent dosemeters (TLDs) before and after application of Quality Control tests and patient dose reduction methods. The paper evidenced the practical influence factors (like the need of use of high voltage technique) and possibilities for dose reduction keeping the image quality. (authors)

  1. Healing X-ray scattering images

    Directory of Open Access Journals (Sweden)

    Jiliang Liu

    2017-07-01

    Full Text Available X-ray scattering images contain numerous gaps and defects arising from detector limitations and experimental configuration. We present a method to heal X-ray scattering images, filling gaps in the data and removing defects in a physically meaningful manner. Unlike generic inpainting methods, this method is closely tuned to the expected structure of reciprocal-space data. In particular, we exploit statistical tests and symmetry analysis to identify the structure of an image; we then copy, average and interpolate measured data into gaps in a way that respects the identified structure and symmetry. Importantly, the underlying analysis methods provide useful characterization of structures present in the image, including the identification of diffuse versus sharp features, anisotropy and symmetry. The presented method leverages known characteristics of reciprocal space, enabling physically reasonable reconstruction even with large image gaps. The method will correspondingly fail for images that violate these underlying assumptions. The method assumes point symmetry and is thus applicable to small-angle X-ray scattering (SAXS data, but only to a subset of wide-angle data. Our method succeeds in filling gaps and healing defects in experimental images, including extending data beyond the original detector borders.

  2. Energy weighted x-ray dark-field imaging.

    Science.gov (United States)

    Pelzer, Georg; Zang, Andrea; Anton, Gisela; Bayer, Florian; Horn, Florian; Kraus, Manuel; Rieger, Jens; Ritter, Andre; Wandner, Johannes; Weber, Thomas; Fauler, Alex; Fiederle, Michael; Wong, Winnie S; Campbell, Michael; Meiser, Jan; Meyer, Pascal; Mohr, Jürgen; Michel, Thilo

    2014-10-06

    The dark-field image obtained in grating-based x-ray phase-contrast imaging can provide information about the objects' microstructures on a scale smaller than the pixel size even with low geometric magnification. In this publication we demonstrate that the dark-field image quality can be enhanced with an energy-resolving pixel detector. Energy-resolved x-ray dark-field images were acquired with a 16-energy-channel photon-counting pixel detector with a 1 mm thick CdTe sensor in a Talbot-Lau x-ray interferometer. A method for contrast-noise-ratio (CNR) enhancement is proposed and validated experimentally. In measurements, a CNR improvement by a factor of 1.14 was obtained. This is equivalent to a possible radiation dose reduction of 23%.

  3. Gonad doses for male patients from stomach examination and oral cholegraphy using the X-ray image intensifying technique and television fluoroscopy

    International Nuclear Information System (INIS)

    Steinbach, W.; Richter, K.; Koenig, W.; Menzel, B.; Reisinger, W.; Uhlich, F.

    1979-01-01

    The gonad dose was measured for male patients undergoing stomach examinations and oral cholegraphy by means of a diagnostic twelve pulse generator (TuR D 1500) and an X-ray apparatus 'Diagnost 100' (Philips-Mueller). In a small group of patients the gonad dose was ascertained per exposure to a 70 mm single spot film, to a 24 cm x 30 cm full size radiograph, and per minute of exposure to image intensifier fluoroscopy. The total gonad dose in both the diagnostic techniques was determined seperately in larger groups of patients. In stomach examination large size radiography led to a gonad dose 20 times higher than that obtained with the spot film technique, while exposure from cholegraphy was 10 times higher. The gonad dose per exposure of a single spot film was about 0.5 mrad. In examinations of the stomach the gonad dose from one minute fluroscopy was 18 times higher than the doses determined for a single spot film, and in cholegraphy it was 10 times higher. Supposing mean values of the number of radiographs and of the fluoroscopy time according to the conditions applied, the gonad dose in stomach examination from the film-screen technique is about twice that from the television image-intensifying technique. By comparison, oral cholegraphy exclusively performed by large-size radiography yielded about the same gonad dose as the spot film television technique. Total dose values determined separately confirmed these evaluations. (author)

  4. Tissue doses in X-ray examinations of osteoarticular system

    International Nuclear Information System (INIS)

    Rabkin, I.Kh.; Stavitskij, R.V.; Blinov, N.N.; Vasil'ev, Yu.D.

    1985-01-01

    The X-ray method in diagnosis of the osteoarticular system disease is described. Problems on tissue dose distribution in X-ray examinations of a skeleton, a skull, humeral articulation, cervical, thoracic and lumbar vertebrae, hip joint, hipbones are considered. The values of specific tissue doses in roentgenography of the osteoarticular system are given

  5. Hard X-ray imaging with a slat collimated telescope

    International Nuclear Information System (INIS)

    Lu Zhuguo; Kotov, Yu.D.; Suslov, A.Yu.

    1995-01-01

    Imaging experiments with a slat collimated hard X-ray telescope are described in this paper demonstrating the feasibility of the direct demodulation imaging method used in hard X-ray scanning modulation experiments. On 25 September 1993 an X-ray raster scan observation of Cyg X-1 was performed in a balloon flight with the hard X-ray telescope HAPI-4. An experiment to image radioactive X-ray sources was performed in the laboratory before. In both experiments the expected X-ray images were obtained, confirming the imaging capability of this method. (orig.)

  6. Analysis of surface absorbed dose in X-ray grating interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhili, E-mail: wangnsrl@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026 (China); Wu, Zhao; Gao, Kun; Wang, Dajiang; Chen, Heng; Wang, Shenghao [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026 (China); Wu, Ziyu, E-mail: wuzy@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026 (China); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2014-10-15

    Highlights: • Theoretical framework for dose estimation in X-ray grating interferometry. • Potential dose reduction of X-ray grating interferometry compared to conventional radiography. • Guidelines for optimization of X-ray grating interferometry for dose-sensitive applications. • Measure to compare various existing X-ray phase contrast imaging techniques. - Abstract: X-ray phase contrast imaging using grating interferometry has shown increased contrast over conventional absorption imaging, and therefore the great potential of dose reduction. The extent of the dose reduction depends on the geometry of grating interferometry, the photon energy, the properties of the sample under investigation and the utilized detector. These factors also determine the capability of grating interferometry to distinguish between different tissues with a specified statistical certainty in a single raw image. In this contribution, the required photon number for imaging and the resulting surface absorbed dose are determined in X-ray grating interferometry, using a two-component imaging object model. The presented results confirm that compared to conventional radiography, phase contrast imaging using grating interferometry indeed has the potential of dose reduction. And the extent of dose reduction is strongly dependent on the imaging conditions. Those results provide a theoretical framework for dose estimation under given imaging conditions before experimental trials, and general guidelines for optimization of grating interferometry for those dose-sensitive applications.

  7. Analysis of surface absorbed dose in X-ray grating interferometry

    International Nuclear Information System (INIS)

    Wang, Zhili; Wu, Zhao; Gao, Kun; Wang, Dajiang; Chen, Heng; Wang, Shenghao; Wu, Ziyu

    2014-01-01

    Highlights: • Theoretical framework for dose estimation in X-ray grating interferometry. • Potential dose reduction of X-ray grating interferometry compared to conventional radiography. • Guidelines for optimization of X-ray grating interferometry for dose-sensitive applications. • Measure to compare various existing X-ray phase contrast imaging techniques. - Abstract: X-ray phase contrast imaging using grating interferometry has shown increased contrast over conventional absorption imaging, and therefore the great potential of dose reduction. The extent of the dose reduction depends on the geometry of grating interferometry, the photon energy, the properties of the sample under investigation and the utilized detector. These factors also determine the capability of grating interferometry to distinguish between different tissues with a specified statistical certainty in a single raw image. In this contribution, the required photon number for imaging and the resulting surface absorbed dose are determined in X-ray grating interferometry, using a two-component imaging object model. The presented results confirm that compared to conventional radiography, phase contrast imaging using grating interferometry indeed has the potential of dose reduction. And the extent of dose reduction is strongly dependent on the imaging conditions. Those results provide a theoretical framework for dose estimation under given imaging conditions before experimental trials, and general guidelines for optimization of grating interferometry for those dose-sensitive applications

  8. Monochromatic x-rays for low-dose digital mammography: preliminary results.

    Science.gov (United States)

    Yoon, Kwon-Ha; Kwon, Young Man; Choi, Byoung-Jung; Son, Hyun Hwa; Ryu, Cheol Woo; Chon, Kwon Su; Park, Seong Hoon; Juhng, Sun Kwan

    2012-12-01

    The feasibility of using monochromatic x-ray imaging generated from an x-ray tube and a multilayer reflector for digital mammography with a low radiation dose was examined. A multilayer mirror was designed to select the x-ray peak with an energy of 21.5 keV generated from an x-ray tube with a tungsten target and was fabricated by the ion-beam sputtering deposition system. Monochromatic x-ray images were obtained from an experimental digital mammography setup with a scanning stage. The performance of the system was evaluated using a breast phantom, a spectrometer, and a radiation dosimeter. We measured the contrast-to-noise ratio and performed the 10% modulation function test to determine image quality and resolution. The monochromatic beam from the multilayer reflector had a full-width-at-half-maximum of 0.9 keV at 21.5 keV, and the reflectivity was 0.70, which was 90% of the designed value. The polychromatic and monochromatic x-rays showed radiation doses of 0.497 and 0.0415 mGy, respectively. The monochromatic x-ray image shows fibers, calcifications, and masses more clearly than the polychromatic x-ray images do. The image contrast of the monochromatic x-rays was 1.85 times higher than that of the polychromatic x-rays. The experimental mammography setup had a spatial resolution of 7 lp/mm with both x-rays. Monochromatic x-rays generated using a multilayer mirror may be a useful diagnostic tool for breast examination by providing high contrast imaging with a low radiation dose.

  9. Dose profile measurement using an imaging plate: Evaluation of filters using Monte Carlo simulation of 4 MV x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Masatoshi [Division of Radiology and Biomedical Engineering, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-8655 (Japan); Department of Therapeutic Radiology, Medical Plaza Edogawa, Edogawa-ku, Tokyo 133-0052 (Japan); Tomita, Tetsuya; Sawada, Koichi [Department of Radiology, Chiba University Hospital, Cyuo-ku, Chiba 260-8677 (Japan); Fujibuchi, Toshioh [Department of Radiological Sciences, School of Health Science, Ibaraki Prefectural University, Inashiki-gun, Ibaraki 300-0394, Japan and Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba-shi, Ibaraki 305-8575 (Japan); Nishio, Teiji [Particle Therapy Division, Research Center for Innovation Oncology, National Cancer Center Hospital East, Kashiwa-shi, Chiba 277-8577 (Japan); Nakagawa, Keiichi [Division of Radiology and Biomedical Engineering, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655 (Japan)

    2009-04-15

    Computed radiography (CR) is gradually replacing film. The application of CR for two-dimensional profiles and off-axis ratio (OAR) measurement using an imaging plate (IP) in a CR system is currently under discussion. However, a well known problem for IPs in dosimetry is that they use high atomic number (Z) materials, such as Ba, which have an energy dependency in a photon interaction. Although there are some reports that it is possible to compensate for the energy dependency with metal filters, the appropriate thicknesses of these filters and where they should be located have not been investigated. The purpose of this study is to find the most suitable filter for use with an IP as a dosimetric tool. Monte Carlo simulation (Geant4 8.1) was used to determine the filter to minimize the measurement error in OAR measurements of 4 MV x-rays. In this simulation, the material and thickness of the filter and distance between the IP and the filter were varied to determine most suitable filter conditions that gave the best fit to the MC calculated OAR in water. With regard to changing the filter material, we found that using higher Z and higher density material increased the effectiveness of the filter. Also, increasing the distance between the filter and the IP reduced the effectiveness, whereas increasing the thickness of the filter increased the effectiveness. The result of this study showed that the most appropriate filter conditions consistent with the calculated OAR in water were the ones with the IP sandwiched between two 2 mm thick lead filters at a distance of 5 mm from the IP or the IP sandwiched directly between two 1 mm lead filters. Using these filters, we measured the OAR at 10 cm depth with 100 cm source-to-surface distance and surface 10x10 cm{sup 2} field size. The results of this measurement represented that it is possible to achieve measurements with less than within 2.0% and 2.0% in the field and with less than 1.1% and 0.6% out of the field by using 2 and

  10. Comparative study of radiation dose between digital panoramic X-ray unit and general panoramic X-ray unit

    International Nuclear Information System (INIS)

    Li Qingshan; Duan Tao; Wang Xiaoyun; Zhao Li; Dong Jian; Wei Lei

    2010-01-01

    Objective: To compare the actual dose of patients who receive the same medical practice by either digital panoramic X-ray unit and general panoramic X-ray unit and give evidence for better selection of oral X-ray examination method. Methods: Round sheet lithium fluoride (LiF) thermoluminescent dosimeters (TLD) were used. The experiment was divided into natural background contrast group, general panoramic X-ray children group, general panoramic X-ray adults group, digital panoramic X-ray children group and digital panoramic X-ray adults group. The dosimeter of natural background radiation was placed at the office of the doctor, the dosimeters of general panoramic X-ray children group and general panoramic X-ray adults group were irradiated by different conditions according to the clinical application of panoramic X-ray to children and adults, the dosimeters of digital panoramic X-ray children group and digital panoramic X-ray adults group were irradiated by different conditions according to the clinical application of digital panoramic X-ray to children and adults. The thermoluminescent dosimeter was used to count and calculate the exposure doses in various groups. Results: The dose of children exposed in general panoramic X-ray unit was 1.28 times of that in digital panoramic X-ray unit, there was significant difference (t=6.904, P<0.01). The dose of adults exposed in general panoramic X-ray unit was 1.55 times of that in the digital panoramic X-ray unit, there also was significant difference (t=-11.514. P< 0.01). Conclusion: The digital panoramic X-ray unit can reduce the dose of patients, so the digital panoramic X-ray unit should be used as far as possible. (authors)

  11. X-ray image signal generator

    International Nuclear Information System (INIS)

    Dalton, B.L.; Lill, B.H.

    1981-01-01

    This patent claim on behalf on EMI Ltd. relates to a flat plate X-ray detector which uses a plate detector exhibiting so-called permanent induced electric polarization in response to a pattern of radiation emergent from a patient to generate a polarization pattern which is scanned by means of a laser to cause discharge of the polarization through the plate and so generate electric signals representative of the X-ray image of the patient. In addition a second laser operating at a different wavelength e.g. infra-red, also scans or floods the plate detector to move 'dark polarisation'. The plate detector may be a phosphor screen or a phosphor screen in combination with a scintillator. (author)

  12. Monolithic CMOS imaging x-ray spectrometers

    Science.gov (United States)

    Kenter, Almus; Kraft, Ralph; Gauron, Thomas; Murray, Stephen S.

    2014-07-01

    The Smithsonian Astrophysical Observatory (SAO) in collaboration with SRI/Sarnoff is developing monolithic CMOS detectors optimized for x-ray astronomy. The goal of this multi-year program is to produce CMOS x-ray imaging spectrometers that are Fano noise limited over the 0.1-10keV energy band while incorporating the many benefits of CMOS technology. These benefits include: low power consumption, radiation "hardness", high levels of integration, and very high read rates. Small format test devices from a previous wafer fabrication run (2011-2012) have recently been back-thinned and tested for response below 1keV. These devices perform as expected in regards to dark current, read noise, spectral response and Quantum Efficiency (QE). We demonstrate that running these devices at rates ~> 1Mpix/second eliminates the need for cooling as shot noise from any dark current is greatly mitigated. The test devices were fabricated on 15μm, high resistivity custom (~30kΩ-cm) epitaxial silicon and have a 16 by 192 pixel format. They incorporate 16μm pitch, 6 Transistor Pinned Photo Diode (6TPPD) pixels which have ~40μV/electron sensitivity and a highly parallel analog CDS signal chain. Newer, improved, lower noise detectors have just been fabricated (October 2013). These new detectors are fabricated on 9μm epitaxial silicon and have a 1k by 1k format. They incorporate similar 16μm pitch, 6TPPD pixels but have ~ 50% higher sensitivity and much (3×) lower read noise. These new detectors have undergone preliminary testing for functionality in Front Illuminated (FI) form and are presently being prepared for back thinning and packaging. Monolithic CMOS devices such as these, would be ideal candidate detectors for the focal planes of Solar, planetary and other space-borne x-ray astronomy missions. The high through-put, low noise and excellent low energy response, provide high dynamic range and good time resolution; bright, time varying x-ray features could be temporally and

  13. Trends in x-ray photography and patient exposure dose

    International Nuclear Information System (INIS)

    Orito, Takeo; Sanada, Shigeru; Maekawa, Ryuichi; Koshida, Kichiro; Hiraki, Tatsunosuke

    1980-01-01

    The exposure doses of patients in X-ray photography are influenced by such technological factors as X-ray tube voltage, filter, sensitizing screen, film and grid. Survey by questionnnaire was made previously in 1973 on the above factors. The trends five years after were surveyed similarly, in connection with the exposure doses of patients. Questionnaires were sent to 200 radiation technicians, and 121 (60.5%) answered the survey in March, 1979. The results in the cases of simple X-ray photography and obstetric, infant and breast X-ray photographings are described. X-ray tube voltage is generally on the increase. In the sensitizing screens, exposure doses are fairly decreased due to the use of improved intensifying screen (LT-II). In the grid, the ratio 8 : 1 is used more than 5 : 1. In the usage of additional filters and in the distance of photography, improvements are desired. (J.P.N.)

  14. Image quality of medical X-ray systems

    International Nuclear Information System (INIS)

    Hoen, P.J. 't.

    1980-01-01

    The quality of images made by medical X-ray systems can only be properly described if the visual system is also taken into account. In this thesis, the visual threshold contrast of edges, bars and disks has been chosen as the criterion. Since these objects resemble medical objects like tumour-mass outlines, blood vessels and micro-calcifications, a correlation with X-ray practice is possible. Only the conventional X-ray systems are considered, but a brief analysis of computerized tomography is given. Considerable attention is paid to unsharpness and the minimization of its influence on the threshold contrast, to the influence of the noise on the threshold contrast, and to the contrast formation as such. The consequences for the dose administered to the patient are also briefly analysed. (Auth.)

  15. Thermoluminescent dosimeters for low dose X-ray measurements

    International Nuclear Information System (INIS)

    Del Sol Fernández, S.; García-Salcedo, R.; Sánchez-Guzmán, D.; Ramírez-Rodríguez, G.; Gaona, E.; León-Alfaro, M.A. de; Rivera-Montalvo, T.

    2016-01-01

    The response of TLD-100, CaSO_4:Dy and LiF:Mg,Cu,P for a range of X-ray low dose was measured. For calibration, the TLDs were arranged at the center of the X-ray field. The dose output of the X-ray machine was determined using an ACCU-Gold. All dosimeters were exposed at the available air kerma values of 14.69 mGy within a field 10×10 cm"2 at 80 cm of SSD. Results of LiF:Mg,Cu,P X-ray irradiated showed 4.8 times higher sensitivity than TLD-100. Meanwhile, TL response of CaSO_4:Dy exposed at the same dose was 5.6 time higher than TLD-100. Experimental results show for low dose X-ray measurements a better linearity for LiF:Mg,Cu,P compared with that of TLD-100. CaSO_4:Dy showed a linearity from 0.1 to 60 mGy - Highlights: • Low dose X-ray doses for personal dosimetry were measured. • Radiation dose (µGy ) for environmental dosimetry were determined. • Scattering radiation dose were measured by TLDs. • Linearity of pair TLD system was successful in the range of microgray. • Pair TLDs composed by CaSO_4:Dy and by LiF:Mg,Cu,P. is suggested for clinical dosimetry.

  16. X-ray spectral decomposition imaging system

    Energy Technology Data Exchange (ETDEWEB)

    1977-07-27

    Projection measurements are made of the transmitted X-ray beam in low and high energy regions. These are combined in a non-linear processor to produce atomic-number-dependent and density-dependent projection information. This information is used to provide cross-sectional images which are free of spectral-shift artifacts and completely define the specific material properties. The invention described herein was made in the course of work under a grant from the Department of Health, Education, and Welfare.

  17. Phosphor Scanner For Imaging X-Ray Diffraction

    Science.gov (United States)

    Carter, Daniel C.; Hecht, Diana L.; Witherow, William K.

    1992-01-01

    Improved optoelectronic scanning apparatus generates digitized image of x-ray image recorded in phosphor. Scanning fiber-optic probe supplies laser light stimulating luminescence in areas of phosphor exposed to x rays. Luminescence passes through probe and fiber to integrating sphere and photomultiplier. Sensitivity and resolution exceed previously available scanners. Intended for use in x-ray crystallography, medical radiography, and molecular biology.

  18. X-ray imaging for security applications

    Science.gov (United States)

    Evans, J. Paul

    2004-01-01

    The X-ray screening of luggage by aviation security personnel may be badly hindered by the lack of visual cues to depth in an image that has been produced by transmitted radiation. Two-dimensional "shadowgraphs" with "organic" and "metallic" objects encoded using two different colors (usually orange and blue) are still in common use. In the context of luggage screening there are no reliable cues to depth present in individual shadowgraph X-ray images. Therefore, the screener is required to convert the 'zero depth resolution' shadowgraph into a three-dimensional mental picture to be able to interpret the relative spatial relationship of the objects under inspection. Consequently, additional cognitive processing is required e.g. integration, inference and memory. However, these processes can lead to serious misinterpretations of the actual physical structure being examined. This paper describes the development of a stereoscopic imaging technique enabling the screener to utilise binocular stereopsis and kinetic depth to enhance their interpretation of the actual nature of the objects under examination. Further work has led to the development of a technique to combine parallax data (to calculate the thickness of a target material) with the results of a basis material subtraction technique to approximate the target's effective atomic number and density. This has been achieved in preliminary experiments with a novel spatially interleaved dual-energy sensor which reduces the number of scintillation elements required by 50% in comparison to conventional sensor configurations.

  19. Aspergillosis - chest x-ray (image)

    Science.gov (United States)

    ... usually occurs in immunocompromised individuals. Here, a chest x-ray shows that the fungus has invaded the lung ... are usually seen as black areas on an x-ray. The cloudiness on the left side of this ...

  20. X-ray diagnostic device with an X-ray image amplifier, whose output image is fed into a movie camera, as well as a brightness control

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, H

    1978-02-09

    The X-ray relief appearing behind a patient is immediately or with amplificating foils converted into a latent film image. By using a X-ray image amplifier the X-ray relief is then converted into a reduced and brighter optical image and fed into a photographic or movie camera and shot. To avoid a reduction in the image quality by quantum noise and a too large patient and physician dose a brightness control is provided for the X-ray diagnostic device. The control only dims as far as a brightness per image is produced that avoids quantum noise. On the other side it opens more by strongly beam absorbing patients or a smaller imaging ratio of the X-ray image amplifier to obtain a desired irradiation.

  1. X-ray diagnostic device with an X-ray image amplifier, whose output image is fed into a movie camera, as well as a brightness control

    International Nuclear Information System (INIS)

    Lutz, H.

    1978-01-01

    The X-ray relief appearing behind a patient is immediately or with amplificating foils converted into a latent film image. By using a X-ray image amplifier the X-ray relief is then converted into a reduced and brighter optical image and fed into a photographic or movie camera and shot. To avoid a reduction in the image quality by quantum noise and a too large patient and physician dose a brightness control is provided for the X-ray diagnostic device. The control only dims as far as a brightness per image is produced that avoids quantum noise. On the other side it opens more by strongly beam absorbing patients or a smaller imaging ratio of the X-ray image amplifier to obtain a desired irradiation. (DG) [de

  2. Low-dose X-ray computed tomography image reconstruction with a combined low-mAs and sparse-view protocol.

    Science.gov (United States)

    Gao, Yang; Bian, Zhaoying; Huang, Jing; Zhang, Yunwan; Niu, Shanzhou; Feng, Qianjin; Chen, Wufan; Liang, Zhengrong; Ma, Jianhua

    2014-06-16

    To realize low-dose imaging in X-ray computed tomography (CT) examination, lowering milliampere-seconds (low-mAs) or reducing the required number of projection views (sparse-view) per rotation around the body has been widely studied as an easy and effective approach. In this study, we are focusing on low-dose CT image reconstruction from the sinograms acquired with a combined low-mAs and sparse-view protocol and propose a two-step image reconstruction strategy. Specifically, to suppress significant statistical noise in the noisy and insufficient sinograms, an adaptive sinogram restoration (ASR) method is first proposed with consideration of the statistical property of sinogram data, and then to further acquire a high-quality image, a total variation based projection onto convex sets (TV-POCS) method is adopted with a slight modification. For simplicity, the present reconstruction strategy was termed as "ASR-TV-POCS." To evaluate the present ASR-TV-POCS method, both qualitative and quantitative studies were performed on a physical phantom. Experimental results have demonstrated that the present ASR-TV-POCS method can achieve promising gains over other existing methods in terms of the noise reduction, contrast-to-noise ratio, and edge detail preservation.

  3. A soft X-ray image of the Moon

    International Nuclear Information System (INIS)

    Schmitt, J.H.M.M.; Aschenbach, B.; Hasinger, G.; Pfeffermann, E.; Predehl, P.; Truemper, J.; Snowden, S.L.; Wisconsin Univ., Madison, WI

    1991-01-01

    A soft X-ray image of the Moon obtained by the Roentgen Observatory Satellite ROSAT clearly shows a sunlit crescent, demonstrating that the Moon's X-ray luminosity arises from backscattering of solar X-rays. The Moon's optically dark side is also X-ray dark, and casts a distinct shadow on the diffuse cosmic X-ray background. Unexpectedly, the dark side seems to emit X-rays at a level about one per cent that of the bright side; this emission very probably results from energetic solar-wind electrons striking the Moon's surface. (author)

  4. A tracking system to calculate patient skin dose in real-time during neurointerventional procedures using a biplane x-ray imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Rana, V. K., E-mail: vkrana@buffalo.edu [Toshiba Stroke and Vascular Research Center, Department of Neurosurgery, State University of New York at Buffalo, Buffalo, New York 14203 (United States); Rudin, S., E-mail: srudin@buffalo.edu; Bednarek, D. R., E-mail: bednarek@buffalo.edu [Toshiba Stroke and Vascular Research Center, Departments of Radiology, Neurosurgery, Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14203 (United States)

    2016-09-15

    Purpose: Neurovascular interventional procedures using biplane fluoroscopic imaging systems can lead to increased risk of radiation-induced skin injuries. The authors developed a biplane dose tracking system (Biplane-DTS) to calculate the cumulative skin dose distribution from the frontal and lateral x-ray tubes and display it in real-time as a color-coded map on a 3D graphic of the patient for immediate feedback to the physician. The agreement of the calculated values with the dose measured on phantoms was evaluated. Methods: The Biplane-DTS consists of multiple components including 3D graphic models of the imaging system and patient, an interactive graphical user interface, a data acquisition module to collect geometry and exposure parameters, the computer graphics processing unit, and functions for determining which parts of the patient graphic skin surface are within the beam and for calculating dose. The dose is calculated to individual points on the patient graphic using premeasured calibration files of entrance skin dose per mAs including backscatter; corrections are applied for field area, distance from the focal spot and patient table and pad attenuation when appropriate. The agreement of the calculated patient skin dose and its spatial distribution with measured values was evaluated in 2D and 3D for simulated procedure conditions using a PMMA block phantom and an SK-150 head phantom, respectively. Dose values calculated by the Biplane-DTS were compared to the measurements made on the phantom surface with radiochromic film and a calibrated ionization chamber, which was also used to calibrate the DTS. The agreement with measurements was specifically evaluated with variation in kVp, gantry angle, and field size. Results: The dose tracking system that was developed is able to acquire data from the two x-ray gantries on a biplane imaging system and calculate the skin dose for each exposure pulse to those vertices of a patient graphic that are determined to be

  5. A tracking system to calculate patient skin dose in real-time during neurointerventional procedures using a biplane x-ray imaging system

    International Nuclear Information System (INIS)

    Rana, V. K.; Rudin, S.; Bednarek, D. R.

    2016-01-01

    Purpose: Neurovascular interventional procedures using biplane fluoroscopic imaging systems can lead to increased risk of radiation-induced skin injuries. The authors developed a biplane dose tracking system (Biplane-DTS) to calculate the cumulative skin dose distribution from the frontal and lateral x-ray tubes and display it in real-time as a color-coded map on a 3D graphic of the patient for immediate feedback to the physician. The agreement of the calculated values with the dose measured on phantoms was evaluated. Methods: The Biplane-DTS consists of multiple components including 3D graphic models of the imaging system and patient, an interactive graphical user interface, a data acquisition module to collect geometry and exposure parameters, the computer graphics processing unit, and functions for determining which parts of the patient graphic skin surface are within the beam and for calculating dose. The dose is calculated to individual points on the patient graphic using premeasured calibration files of entrance skin dose per mAs including backscatter; corrections are applied for field area, distance from the focal spot and patient table and pad attenuation when appropriate. The agreement of the calculated patient skin dose and its spatial distribution with measured values was evaluated in 2D and 3D for simulated procedure conditions using a PMMA block phantom and an SK-150 head phantom, respectively. Dose values calculated by the Biplane-DTS were compared to the measurements made on the phantom surface with radiochromic film and a calibrated ionization chamber, which was also used to calibrate the DTS. The agreement with measurements was specifically evaluated with variation in kVp, gantry angle, and field size. Results: The dose tracking system that was developed is able to acquire data from the two x-ray gantries on a biplane imaging system and calculate the skin dose for each exposure pulse to those vertices of a patient graphic that are determined to be

  6. Submicron, soft x-ray fluorescence imaging

    International Nuclear Information System (INIS)

    La Fontaine, B.; MacDowell, A.A.; Tan, Z.; White, D.L.; Taylor, G.N.; Wood, O.R. II; Bjorkholm, J.E.; Tennant, D.M.; Hulbert, S.L.

    1995-01-01

    Submicron fluorescence imaging of soft x-ray aerial images, using a high resolution fluorescent crystal is reported. Features as small as 0.1 μm were observed using a commercially available single-crystal phosphor, STI-F10G (Star Tech Instruments Inc. P. O. Box 2536, Danbury, CT 06813-2536), excited with 139 A light. Its quantum efficiency was estimated to be 5--10 times that of sodium salicylate and to be constant over a broad spectral range from 30 to 400 A. A comparison with a terbium-activated yttrium orthosilicate fluorescent crystal is also presented. Several applications, such as the characterization of the aerial images produced by deep ultraviolet or extreme ultraviolet lithographic exposure tools, are envisaged

  7. X-ray diagnostic installation for X-ray tomographic images

    International Nuclear Information System (INIS)

    Haendle, J.; Sklebitz, H.

    1984-01-01

    An exemplary embodiment includes at least one x-ray tube for the generation of an x-ray beam, a patient support, an image detector, and a control generator-connected with the x-ray tube and the image detector-for the purpose of moving the x-ray beam, and in opposition thereto, the image field of the image detector. There is connected to the control generator a layer height computer which calculates the enlargement from the geometric data for the tomogram. The image detector has a circuit-connected with the layer height computer-for the purpose of fading-in a marking for the dimensions in the layer plane

  8. Optimum power of radiation dose in X ray television systems of flaw inspection in industry

    International Nuclear Information System (INIS)

    Denbnovetskii, S.V.; Troitskii, V.A.; Belyi, N.G.; Grom, V.S.; Kuz'micheva, N.V.; Leshchishin, A.V.; Mikhailov, V.N.; Shutenko, O.V.

    1990-01-01

    The authors present the experimental dose characteristics of a x ray television system based on x ray vidicons with the diameter of the working field of 900 mm which operate in the continuous and pulsed conditions with the longer time of cumulation of radiation images on the target of the x ray vidicon. For each type of the inspected material, its thickness, and cumulation time, the dose characteristics were used to determine the optimum power of the exposure dose ensuring the maximum signal/noise ratio and detectability of the defects at the output of the system. (author)

  9. Wavelength dispersive X-ray absorption fine structure imaging by parametric X-ray radiation

    International Nuclear Information System (INIS)

    Inagaki, Manabu; Sakai, Takeshi; Sato, Isamu; Hayakawa, Yasushi; Nogami, Kyoko; Tanaka, Toshinari; Hayakawa, Ken; Nakao, Keisuke

    2008-01-01

    The parametric X-ray radiation (PXR) generator system at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University is a monochromatic and coherent X-ray source with horizontal wavelength dispersion. The energy definition of the X-rays, which depends on the horizontal size of the incident electron beam on the generator target crystal, has been investigated experimentally by measuring the X-ray absorption near edge structure (XANES) spectra on Cu and CuO associated with conventional X-ray absorption imaging technique. The result demonstrated the controllability of the spectrum resolution of XANES by adjusting of the horizontal electron beam size on the target crystal. The XANES spectra were obtained with energy resolution of several eV at the narrowest case, which is in qualitative agreement with the energy definition of the PXR X-rays evaluated from geometrical consideration. The result also suggested that the wavelength dispersive X-ray absorption fine structure measurement associated with imaging technique is one of the promising applications of PXR. (author)

  10. Dual-gate photo thin-film transistor: a “smart” pixel for high- resolution and low-dose X-ray imaging

    Science.gov (United States)

    Wang, Kai; Ou, Hai; Chen, Jun

    2015-06-01

    Since its emergence a decade ago, amorphous silicon flat panel X-ray detector has established itself as a ubiquitous platform for an array of digital radiography modalities. The fundamental building block of a flat panel detector is called a pixel. In all current pixel architectures, sensing, storage, and readout are unanimously kept separate, inevitably compromising resolution by increasing pixel size. To address this issue, we hereby propose a “smart” pixel architecture where the aforementioned three components are combined in a single dual-gate photo thin-film transistor (TFT). In other words, the dual-gate photo TFT itself functions as a sensor, a storage capacitor, and a switch concurrently. Additionally, by harnessing the amplification effect of such a thin-film transistor, we for the first time created a single-transistor active pixel sensor. The proof-of-concept device had a W/L ratio of 250μm/20μm and was fabricated using a simple five-mask photolithography process, where a 130nm transparent ITO was used as the top photo gate, and a 200nm amorphous silicon as the absorbing channel layer. The preliminary results demonstrated that the photocurrent had been increased by four orders of magnitude due to light-induced threshold voltage shift in the sub-threshold region. The device sensitivity could be simply tuned by photo gate bias to specifically target low-level light detection. The dependence of threshold voltage on light illumination indicated that a dynamic range of at least 80dB could be achieved. The "smart" pixel technology holds tremendous promise for developing high-resolution and low-dose X-ray imaging and may potentially lower the cancer risk imposed by radiation, especially among paediatric patients.

  11. Dual-gate photo thin-film transistor: a “smart” pixel for high- resolution and low-dose X-ray imaging

    International Nuclear Information System (INIS)

    Wang, Kai; Ou, Hai; Chen, Jun

    2015-01-01

    Since its emergence a decade ago, amorphous silicon flat panel X-ray detector has established itself as a ubiquitous platform for an array of digital radiography modalities. The fundamental building block of a flat panel detector is called a pixel. In all current pixel architectures, sensing, storage, and readout are unanimously kept separate, inevitably compromising resolution by increasing pixel size. To address this issue, we hereby propose a “smart” pixel architecture where the aforementioned three components are combined in a single dual-gate photo thin-film transistor (TFT). In other words, the dual-gate photo TFT itself functions as a sensor, a storage capacitor, and a switch concurrently. Additionally, by harnessing the amplification effect of such a thin-film transistor, we for the first time created a single-transistor active pixel sensor. The proof-of-concept device had a W/L ratio of 250μm/20μm and was fabricated using a simple five-mask photolithography process, where a 130nm transparent ITO was used as the top photo gate, and a 200nm amorphous silicon as the absorbing channel layer. The preliminary results demonstrated that the photocurrent had been increased by four orders of magnitude due to light-induced threshold voltage shift in the sub-threshold region. The device sensitivity could be simply tuned by photo gate bias to specifically target low-level light detection. The dependence of threshold voltage on light illumination indicated that a dynamic range of at least 80dB could be achieved. The 'smart' pixel technology holds tremendous promise for developing high-resolution and low-dose X-ray imaging and may potentially lower the cancer risk imposed by radiation, especially among paediatric patients. (paper)

  12. Apparatus and method X-ray image processing

    International Nuclear Information System (INIS)

    1984-01-01

    The invention relates to a method for X-ray image processing. The radiation passed through the object is transformed into an electric image signal from which the logarithmic value is determined and displayed by a display device. Its main objective is to provide a method and apparatus that renders X-ray images or X-ray subtraction images with strong reduction of stray radiation. (Auth.)

  13. X-ray diffraction imaging of material microstructures

    KAUST Repository

    Varga, Laszlo

    2016-10-20

    Various examples are provided for x-ray imaging of the microstructure of materials. In one example, a system for non-destructive material testing includes an x-ray source configured to generate a beam spot on a test item; a grid detector configured to receive x- rays diffracted from the test object; and a computing device configured to determine a microstructure image based at least in part upon a diffraction pattern of the x-rays diffracted from the test object. In another example, a method for determining a microstructure of a material includes illuminating a beam spot on the material with a beam of incident x-rays; detecting, with a grid detector, x-rays diffracted from the material; and determining, by a computing device, a microstructure image based at least in part upon a diffraction pattern of the x-rays diffracted from the material.

  14. Multiflash X ray with Image Detanglement for Single Image Isolation

    Science.gov (United States)

    2017-08-31

    known and separated into individual images. A proof-of- principle study was performed using 4 X-ray flashes and copper masks with sub-millimeter holes...Popular Science article.2 For decades, that basic concept dominated the color television market . Those were the days when a large color television...proof-of- principle study was performed using 4 X-ray flashes and copper masks with sub-millimeter holes that allowed development of the required image

  15. Exposure reduction in general dental practice using digital x-ray imaging system for intraoral radiography with additional x-ray beam filter

    International Nuclear Information System (INIS)

    Shibuya, Hitoshi; Mori, Toshimichi; Hayakawa, Yoshihiko; Kuroyanagi, Kinya; Ota, Yoshiko

    1997-01-01

    To measure exposure reduction in general dental practice using digital x-ray imaging systems for intraoral radiography with additional x-ray beam filter. Two digital x-ray imaging systems, Pana Digital (Pana-Heraus Dental) and CDR (Schick Technologies), were applied for intraoral radiography in general dental practice. Due to the high sensitivity to x-rays, additional x-ray beam filters for output reduction were used for examination. An Orex W II (Osada Electric Industry) x-ray generator was operated at 60 kVp, 7 mA. X-ray output (air-kerma; Gy) necessary for obtaining clinically acceptable images was measured at 0 to 20 cm in 5 cm steps from the cone tip using an ionizing chamber type 660 (Nuclear Associates) and compared with those for Ektaspeed Plus film (Eastman Kodak). The Pana Digital system was used with the optional filter supplied by Pana-Heraus Dental which reduced the output to 38%. The exposure necessary to obtain clinically acceptable images was only 40% of that for the film. The CDR system was used with the Dental X-ray Beam Filter Kit (Eastman Kodak) which reduced the x-ray output to 30%. The exposure necessary to obtain clinically acceptable images was only 20% of that for the film. The two digital x-ray imaging systems, Pana Digital and CDR, provided large dose savings (60-80%) compared with Ektaspeed Plus film when applied for intraoral radiography in general dental practice. (author)

  16. Study of x-ray CCD image sensor and application

    Science.gov (United States)

    Wang, Shuyun; Li, Tianze

    2008-12-01

    In this paper, we expounded the composing, specialty, parameter, its working process, key techniques and methods for charge coupled devices (CCD) twice value treatment. Disposal process for CCD video signal quantification was expatiated; X-ray image intensifier's constitutes, function of constitutes, coupling technique of X-ray image intensifier and CCD were analyzed. We analyzed two effective methods to reduce the harm to human beings when X-ray was used in the medical image. One was to reduce X-ray's radiation and adopt to intensify the image penetrated by X-ray to gain the same effect. The other was to use the image sensor to transfer the images to the safe area for observation. On this base, a new method was presented that CCD image sensor and X-ray image intensifier were combined organically. A practical medical X-ray photo electricity system was designed which can be used in the records and time of the human's penetrating images. The system was mainly made up with the medical X-ray, X-ray image intensifier, CCD vidicon with high resolution, image processor, display and so on. Its characteristics are: change the invisible X-ray into the visible light image; output the vivid images; short image recording time etc. At the same time we analyzed the main aspects which affect the system's resolution. Medical photo electricity system using X-ray image sensor can reduce the X-ray harm to human sharply when it is used in the medical diagnoses. At last we analyzed and looked forward the system's application in medical engineering and the related fields.

  17. X-ray elastography: Modification of x-ray phase contrast images using ultrasonic radiation pressure

    International Nuclear Information System (INIS)

    Hamilton, Theron J.; Bailat, Claude; Rose-Petruck, Christoph; Diebold, Gerald J.; Gehring, Stephan; Laperle, Christopher M.; Wands, Jack

    2009-01-01

    The high resolution characteristic of in-line x-ray phase contrast imaging can be used in conjunction with directed ultrasound to detect small displacements in soft tissue generated by differential acoustic radiation pressure. The imaging method is based on subtraction of two x-ray images, the first image taken with, and the second taken without the presence of ultrasound. The subtraction enhances phase contrast features and, to a large extent, removes absorption contrast so that differential movement of tissues with different acoustic impedances or relative ultrasonic absorption is highlighted in the image. Interfacial features of objects with differing densities are delineated in the image as a result of both the displacement introduced by the ultrasound and the inherent sensitivity of x-ray phase contrast imaging to density variations. Experiments with ex vivo murine tumors and human tumor phantoms point out a diagnostic capability of the method for identifying tumors.

  18. Adenocarcinoma - chest x-ray (image)

    Science.gov (United States)

    This chest x-ray shows adenocarcinoma of the lung. There is a rounded light spot in the right upper lung (left side ... density. Diseases that may cause this type of x-ray result would be tuberculous or fungal granuloma, and ...

  19. Tolerance limits of X-ray image intensity

    International Nuclear Information System (INIS)

    Stargardt, A.; Juran, R.; Brandt, G.A.

    1985-01-01

    Evaluation of the tolerance limits of X-ray image density accepted by the radiologist shows that for different kinds of examinations, deviations of more than 50% from optimal density lead to images which cannot be used diagnostically. Within this range diagnostic accuracy shows a distinct maximum and diminishes to the limits by 20%. These figures are related to differences in the intensifying factor of screens, sensitivity of films, sensitometric parameters of film processing as well as the doses employed with automatic exposure control devices, measured in clinical conditions. Maximum permissible tolerance limits of the whole imaging system and of its constituents are discussed using the Gaussian law of error addition. (author)

  20. Automated processing of X-ray images in medicine

    International Nuclear Information System (INIS)

    Babij, Ya.S.; B'yalyuk, Ya.O.; Yanovich, I.A.; Lysenko, A.V.

    1991-01-01

    Theoretical and practical achievements in application of computing technology means for processing of X-ray images in medicine were generalized. The scheme of the main directions and tasks of processing of X-ray images was given and analyzed. The principal problems appeared in automated processing of X-ray images were distinguished. It is shown that for interpretation of X-ray images it is expedient to introduce a notion of relative operating characteristic (ROC) of a roentgenologist. Every point on ROC curve determines the individual criteria of roentgenologist to put a positive diagnosis for definite situation

  1. X-ray imaging with the PILATUS 100k detector

    DEFF Research Database (Denmark)

    Bech, Martin; Bunk, O.; David, C.

    2008-01-01

    We report on the application of the PILATUS 100K pixel detector for medical imaging. Experimental results are presented in the form of X-ray radiographs using standard X-ray absorption contrast and a recently developed phase contrast imaging method. The results obtained with the PILATUS detector...... are compared to results obtained with a conventional X-ray imaging system consisting of an X-ray scintillation screen, lens optics, and a charge coupled device. Finally, the results for both systems are discussed more quantitatively based on an image power spectrum analysis. Udgivelsesdato: April...

  2. Image Analysis for X-ray Imaging of Food

    DEFF Research Database (Denmark)

    Einarsdottir, Hildur

    for quality and safety evaluation of food products. In this effort the fields of statistics, image analysis and statistical learning are combined, to provide analytical tools for determining the aforementioned food traits. The work demonstrated includes a quantitative analysis of heat induced changes......X-ray imaging systems are increasingly used for quality and safety evaluation both within food science and production. They offer non-invasive and nondestructive penetration capabilities to image the inside of food. This thesis presents applications of a novel grating-based X-ray imaging technique...... and defect detection in food. Compared to the complex three dimensional analysis of microstructure, here two dimensional images are considered, making the method applicable for an industrial setting. The advantages obtained by grating-based imaging are compared to conventional X-ray imaging, for both foreign...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... that might interfere with the x-ray images. Women should always inform their physician and x-ray ... Safety page for more information about radiation dose. Women should always inform their physician or x-ray ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ...

  5. X-ray phase imaging using a X-ray tube with a small focal spot. Improvement of image quality in mammography

    International Nuclear Information System (INIS)

    Honda, Chika; Ohara, Hiromu; Ishisaka, Akira; Shimada, Fumio

    2002-01-01

    Phase contrast X-ray imaging has been studied intensively using X-rays from synchrotron radiation and micro-focus X-ray tubes. However, these studies have revealed the difficulty of this technique's application to practical medical imaging. We have created a phase contrast imaging technique using a molybdenum X-ray tube with a small focal spot size for mammography. We identified the radiographic conditions in phase contrast magnification mammography with a screen-film system, where edge effect due to phase contrast overcomes geometrical unsharpness caused by the 0.1 mm-focal spot of a molybdenum X-ray tube. The edge enhancement due to phase imaging was observed in an image of a plastic tube, and then geometrical configuration of the X-ray tube, the object and the screen-film system was determined for phase imaging of mammography. In order to investigate a potential for medical application of this method, we conducted evaluation of the images of the American Collage of Radiology (ACR) 156 mammography phantom. We obtained higher scores for phase imaging using high speed screen-film systems without any increase of X-ray dose than the score for contract imaging using a standard speed screen-film system. (author)

  6. Shield device for controlling the dose of x-rays applied in an x-ray machine

    International Nuclear Information System (INIS)

    Charrier, P.

    1983-01-01

    This invention provides an improved shield for use with an x-ray machine. The shield can control the dose of x-rays applied by the machine in different areas without affecting the power of the x-rays. This is achieved with a shield especially designed and positioned to intercept with x-rays for longer or shorter periods in different areas during the taking of the picture, but not for the whole period of time necessary for taking this picture. Each area of the subject being x-rayed is exposed to full power x-rays. However, owing to the shield, the areas that require smaller dose receive these full power x-rays for a shorter portion of the time required to take the picture while the other areas that require larger dose of x-rays, receive the full power x-rays for a longer portion of the full period of time required to take the picture. To ensure this differential exposure, the shield is placed through the path of the x-rays and rotated about an axis which is generally transverse to the direction of travel of the x-rays to cut out some of said x-rays for different portions of the period of time necessary for taking the picture. The shield is preferably shaped to intercept x-rays for a longer period in some areas than in others depending on the required doses. A plurality of differently shaped shields can be provided to suit different picture taking situations

  7. Two digital X-ray imaging systems for applications in X-ray diffraction

    International Nuclear Information System (INIS)

    Bateman, J.E.; Connolly, J.F.; Stephenson, R.; Flesher, A.C.; Bryant, C.J.; Lincoln, A.D.; Tucker, P.A.; Swanton, S.W.

    1986-08-01

    Two digital X-ray imaging systems developed at the Rutherford Appleton Laboratory are described:- the Mark I and the Mark II. Both use a bidimensionally sensitive Multiwire proportional counter as the basic X-ray image transducer coupled to a digital microcomputer system. The Mark I system provides the advantages of high speed, high sensitivity digital imaging directly into the computer with the potential for software control of the sample orientation and environment. The Mark II system adds the novel features of signal averaging and multi-frame exposures. (author)

  8. Tuberculosis, advanced - chest x-rays (image)

    Science.gov (United States)

    Tuberculosis is an infectious disease that causes inflammation, the formation of tubercules and other growths within tissue, ... death. These chest x-rays show advanced pulmonary tuberculosis. There are multiple light areas (opacities) of varying ...

  9. Computerized x-ray dose-monitoring system

    International Nuclear Information System (INIS)

    Hummel, R.H.; Wesenberg, R.L.; Amundson, G.M.

    1985-01-01

    An x-ray dose-monitoring system using a small digital computer is described. Initially, and for every 6 months afterward, the system is calibrated using an exposure meter. For each exposure, the computer receives values of x-ray technique and beam geometry from the x-ray generator through a specially designed electronic interface. Then, by means of calibration data, entrance exposure, area exposure product, and integral dose are obtained and printed for each patient examined. The overall accuracy of the system is better than +/-20%. Operation is semiautomatic, requiring minimum operator intervention. Over 2000 patients have been monitored with the device. Because the system is computer-based, it offers the opportunity for statistical analysis of the data base created, as the results for each patient are stored on computer disk

  10. Dental x-ray image segmentation

    Science.gov (United States)

    Said, Eyad; Fahmy, Gamal F.; Nassar, Diaa; Ammar, Hany

    2004-08-01

    Law enforcement agencies have been exploiting biometric identifiers for decades as key tools in forensic identification. With the evolution in information technology and the huge volume of cases that need to be investigated by forensic specialists, it has become important to automate forensic identification systems. While, ante mortem (AM) identification, that is identification prior to death, is usually possible through comparison of many biometric identifiers, postmortem (PM) identification, that is identification after death, is impossible using behavioral biometrics (e.g. speech, gait). Moreover, under severe circumstances, such as those encountered in mass disasters (e.g. airplane crashers) or if identification is being attempted more than a couple of weeks postmortem, under such circumstances, most physiological biometrics may not be employed for identification, because of the decay of soft tissues of the body to unidentifiable states. Therefore, a postmortem biometric identifier has to resist the early decay that affects body tissues. Because of their survivability and diversity, the best candidates for postmortem biometric identification are the dental features. In this paper we present an over view about an automated dental identification system for Missing and Unidentified Persons. This dental identification system can be used by both law enforcement and security agencies in both forensic and biometric identification. We will also present techniques for dental segmentation of X-ray images. These techniques address the problem of identifying each individual tooth and how the contours of each tooth are extracted.

  11. The display of X-ray images

    International Nuclear Information System (INIS)

    1974-01-01

    In order to decrease the radiation doses incurred by radiological investigation of patients, a method is developed to fix an image on a screen in a thermoluminescent phosphor and subsequently heating that phosphor by scanning the screen with a laser

  12. New intraoral x-ray fluorographic imaging for dentistry

    International Nuclear Information System (INIS)

    Higashi, T.; Osada, T.; Aoyama, W.; Iguchi, M.; Suzuki, S.; Kanno, M.; Moriya, K.; Yoshimura, M.; Tusuda, M.

    1983-01-01

    A new dental x-ray fluorographic unit has been developed. This unit is composed of small intraoral x-ray tube, a compact x-ray image intensifier, and a high-resolution TV system. The purposes for developing this equipment were to (1) directly observe the tooth during endodontic procedures and (2) reduce x-ray exposure to the patient and the dentist. The radiation exposure can be reduced to about 1/600 the exposure used with conventional dental film. In clinical trials, a satisfactory fluorographic dental image for endodontic treatment was obtained with this new device

  13. Quantitative cone beam X-ray luminescence tomography/X-ray computed tomography imaging

    International Nuclear Information System (INIS)

    Chen, Dongmei; Zhu, Shouping; Chen, Xueli; Chao, Tiantian; Cao, Xu; Zhao, Fengjun; Huang, Liyu; Liang, Jimin

    2014-01-01

    X-ray luminescence tomography (XLT) is an imaging technology based on X-ray-excitable materials. The main purpose of this paper is to obtain quantitative luminescence concentration using the structural information of the X-ray computed tomography (XCT) in the hybrid cone beam XLT/XCT system. A multi-wavelength luminescence cone beam XLT method with the structural a priori information is presented to relieve the severe ill-posedness problem in the cone beam XLT. The nanophosphors and phantom experiments were undertaken to access the linear relationship of the system response. Then, an in vivo mouse experiment was conducted. The in vivo experimental results show that the recovered concentration error as low as 6.67% with the location error of 0.85 mm can be achieved. The results demonstrate that the proposed method can accurately recover the nanophosphor inclusion and realize the quantitative imaging

  14. Assessment of pediatrics radiation dose from routine x-ray ...

    African Journals Online (AJOL)

    Background: Given the fact that children are more sensitive to ionizing radiation than adults,with an increased risk of developing radiation-induced cancer,special care should be taken when they undergo X-ray examinations. The main aim of the current study was to determine Entrance Surface Dose (ESD) to pediatric ...

  15. SU-D-204-06: Dose and Image Quality Evaluation of a Low-Dose Slot-Scanning X-Ray System for Pediatric Orthopedic Studies

    International Nuclear Information System (INIS)

    Liu, Z; Hoerner, M; Lamoureux, R; Rill, L; Arreola, M

    2015-01-01

    Purpose: Children in early teens with scoliosis require repeated radiographic exams over a number of years. The EOS (EOS imaging S.A., Paris, France) is a novel low-dose slot-scanning digital radiographic system designed to produce full-spine images of a free-standing patient. The radiation dose and image quality characteristics of the EOS were evaluated relative to those of a Computed Radiography (CR) system for scoliosis imaging. Methods: For dose evaluation, a full-torso anthropomorphic phantom was scanned five times using the default standard clinical protocols for both the EOS and a CR system, which include both posteroanterior and lateral full-spine views. Optically stimulated luminescent dosimeters (OSLDs), also known as nanoDots™ (Landauer, Inc., Glenwood, IL), were placed on the phantom’s surface to measure entrance skin dose. To assess image quality, MTF curves were generated from sampling the noise levels within the high-contrast regions of a line-pair phantom. Vertical and horizontal distortions were measured for the square line-pair phantom with the EOS system to evaluate the effects of geometric magnification and misalignment with the indicated imaging plane. Results: The entrance skin dose was measured to be 0.4 to 1.1 mGy for the EOS, and 0.7 to 3.6 mGy for the CR study. MTF comparison shows that CR greatly outperforms the EOS, despite both systems having a limiting resolution at 1.8 line-pairs per mm. Vertical distortion was unaffected by phantom positioning, because of the EOS slot-scanning geometry. Horizontal distortion increased linearly with miscentering distance. Conclusion: The EOS system resulted in approximately 70% lower radiation dose than CR for full-spine images. Image quality was found to be inferior to CR. Further investigation is required to see if EOS system is an acceptable modality for performing clinically diagnostic scoliosis examinations

  16. SU-D-204-06: Dose and Image Quality Evaluation of a Low-Dose Slot-Scanning X-Ray System for Pediatric Orthopedic Studies

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Z; Hoerner, M; Lamoureux, R; Rill, L; Arreola, M [Univ Florida, Jacksonville Beach, FL (United States)

    2015-06-15

    Purpose: Children in early teens with scoliosis require repeated radiographic exams over a number of years. The EOS (EOS imaging S.A., Paris, France) is a novel low-dose slot-scanning digital radiographic system designed to produce full-spine images of a free-standing patient. The radiation dose and image quality characteristics of the EOS were evaluated relative to those of a Computed Radiography (CR) system for scoliosis imaging. Methods: For dose evaluation, a full-torso anthropomorphic phantom was scanned five times using the default standard clinical protocols for both the EOS and a CR system, which include both posteroanterior and lateral full-spine views. Optically stimulated luminescent dosimeters (OSLDs), also known as nanoDots™ (Landauer, Inc., Glenwood, IL), were placed on the phantom’s surface to measure entrance skin dose. To assess image quality, MTF curves were generated from sampling the noise levels within the high-contrast regions of a line-pair phantom. Vertical and horizontal distortions were measured for the square line-pair phantom with the EOS system to evaluate the effects of geometric magnification and misalignment with the indicated imaging plane. Results: The entrance skin dose was measured to be 0.4 to 1.1 mGy for the EOS, and 0.7 to 3.6 mGy for the CR study. MTF comparison shows that CR greatly outperforms the EOS, despite both systems having a limiting resolution at 1.8 line-pairs per mm. Vertical distortion was unaffected by phantom positioning, because of the EOS slot-scanning geometry. Horizontal distortion increased linearly with miscentering distance. Conclusion: The EOS system resulted in approximately 70% lower radiation dose than CR for full-spine images. Image quality was found to be inferior to CR. Further investigation is required to see if EOS system is an acceptable modality for performing clinically diagnostic scoliosis examinations.

  17. The effect of well-characterized, very low-dose x-ray radiation on fibroblasts.

    Science.gov (United States)

    Truong, Katelyn; Bradley, Suzanne; Baginski, Bryana; Wilson, Joseph R; Medlin, Donald; Zheng, Leon; Wilson, R Kevin; Rusin, Matthew; Takacs, Endre; Dean, Delphine

    2018-01-01

    The purpose of this study is to determine the effects of low-dose radiation on fibroblast cells irradiated by spectrally and dosimetrically well-characterized soft x-rays. To achieve this, a new cell culture x-ray irradiation system was designed. This system generates characteristic fluorescent x-rays to irradiate the cell culture with x-rays of well-defined energies and doses. 3T3 fibroblast cells were cultured in cups with Mylar® surfaces and were irradiated for one hour with characteristic iron (Fe) K x-ray radiation at a dose rate of approximately 550 μGy/hr. Cell proliferation, total protein analysis, flow cytometry, and cell staining were performed on fibroblast cells to determine the various effects caused by the radiation. Irradiated cells demonstrated increased proliferation and protein production compared to control samples. Flow cytometry revealed that a higher percentage of irradiated cells were in the G0/G1 phase of the cell cycle compared to control counterparts, which is consistent with other low-dose studies. Cell staining results suggest that irradiated cells maintained normal cell functions after radiation exposure, as there were no qualitative differences between the images of the control and irradiated samples. The result of this study suggest that low-dose soft x-ray radiation might cause an initial pause, followed by a significant increase, in proliferation. An initial "pause" in cell proliferation could be a protective mechanism of the cells to minimize DNA damage caused by radiation exposure. The new cell irradiation system developed here allows for unprecedented control over the properties of the x-rays given to the cell cultures. This will allow for further studies on various cell types with known spectral distribution and carefully measured doses of radiation, which may help to elucidate the mechanisms behind varied cell responses to low-dose x-rays reported in the literature.

  18. Effect of x-ray tube parameters and iodine concentration on image quality and radiation dose in cerebral pediatric and adult CT angiography: a phantom study.

    Science.gov (United States)

    Papadakis, Antonios E; Perisinakis, Kostas; Raissaki, Maria; Damilakis, John

    2013-04-01

    The aim of the present phantom study was to investigate the effect of x-ray tube parameters and iodine concentration on image quality and radiation dose in cerebral computed tomographic (CT) angiographic examinations of pediatric and adult individuals. Four physical anthropomorphic phantoms that represent the average individual as neonate, 1-year-old, 5-year-old, and 10-year-old children and the RANDO phantom that simulates the average adult individual were used. Cylindrical vessels were bored along the brain-equivalent plugs of each physical phantom. To simulate the brain vasculature, vessels of 0.6, 1, 2, and 3 mm in diameter were created. These vessels were filled with contrast medium (CM) solutions at different iodine concentrations, that is, 5.6, 4.2, 2.7, and 1.4 mg I/mL. The phantom heads were scanned at 120, 100, and 80 kV. The applied quality reference tube current-time product values ranged from a minimum of 45 to a maximum of 680. The CT acquisitions were performed on a 16-slice CT scanner using the automatic exposure control system. Image quality was evaluated on the basis of image noise and contrast-to-noise ratio (CNR) between the contrast-enhanced iodinated vessels and the unenhanced regions of interest. Dose reduction was calculated as the percentage difference of the CT dose index value at the quality reference tube current-time product and the CT dose index at the mean modulated tube current-time product. Image noise that was measured using the preset tube current-time product settings varied significantly among the different phantoms (P Hounsfield unit number of iodinated vessels was linearly related to CM concentration (r² = 0.907) and vessel diameter (r² = 0.918). The Hounsfield unit number of iodinated vessels followed a decreasing trend from the neonate phantom to the adult phantom at all kilovoltage settings. For the same image noise level, a CNR improvement of up to 69% and a dose reduction of up to 61% may be achieved when CT acquisition

  19. Material Discriminated X-Ray CT System by Using New X-Ray Imager with Energy Discriminate Function

    Directory of Open Access Journals (Sweden)

    Toru Aoki

    2008-04-01

    Full Text Available Material discriminated X-ray CT system has been constructed by using conventional X-ray tube (white X-ray source and photon-counting X-ray imager as an application with energy band detection. We have already reported material identify X-ray CT using K-shell edge method elsewhere. In this report the principle of material discrimination was adapted the separation of electron-density and atomic number from attenuation coefficient mapping in X-ray CT reconstructed image in two wavelength X-ray CT method using white X-ray source and energy discriminated X-ray imager by using two monochrome X-ray source method. The measurement phantom was prepared as four kinds material rods (Carbon(C, Iron(Fe, Copper(Cu, Titanium(Ti rods of 3mm-diameter inside an aluminum(Al rod of 20mm-diameter. We could observed material discriminated X-ray CT reconstructed image, however, the discrimination properties were not good than two monochrome X-ray CT method. This results was could be explained because X-ray scattering, beam-hardening and so on based on white X-ray source, which could not observe in two monochrome X-ray CT method. However, since our developed CdTe imager can be detect five energy-bands at the same time, we can use multi-band analysis to decrease the least square error margin. We will be able to obtain more high separation in atomic number mapping in X-ray CT reconstructed image by using this system.

  20. Real-time digital x-ray subtraction imaging

    International Nuclear Information System (INIS)

    Mistretta, C.A.; Kruger, R.A.; Houk, T.L.

    1982-01-01

    A method of producing visible difference images derived from an x-ray image of an anatomical subject is described. X-rays are directed through the subject, and the image is converted into television fields comprising trains of analog video signals. The analog signals are converted into digital signals, which are then integrated over a predetermined time corresponding to several television fields. Difference video signals are produced by performing a subtraction between the ongoing video signals and the corresponding integrated signals, and are converted into visible television difference images representing changes in the x-ray image

  1. Image formation in diagnostic X-ray equipment

    International Nuclear Information System (INIS)

    Boer, J.A. den.

    1983-01-01

    This thesis deals with a physical description of the image formation in static radiographic shadow image X-ray equipment and an analysis of the optimization of such systems. For the latter criteria have been developed that take into account all relevant physical phenomena that relate to properties of the image and the radiation exposure of the patient. The discussion of image formation results in a number of relations between the X-ray system parameters on the one hand and properties of the X-ray image on the other. The three principal aspects considered are energy transfer, modulation transfer and noise. (Auth./C.F.)

  2. Evaluating fracture healing using digital x-ray image analysis

    African Journals Online (AJOL)

    2011-03-02

    Mar 2, 2011 ... with intensive imaging and modelling.6 dual energy X-ray ... techniques due to their high-quality digital output in ... the bone in the loaded X-ray is at an angular offset due to .... The research described in this article was carried ...

  3. X-ray diffraction imaging of material microstructures

    KAUST Repository

    Varga, Laszlo; Varga, Bonbien; Calo, Victor

    2016-01-01

    Various examples are provided for x-ray imaging of the microstructure of materials. In one example, a system for non-destructive material testing includes an x-ray source configured to generate a beam spot on a test item; a grid detector configured

  4. Infrared Radiography: Modeling X-ray Imaging without Harmful Radiation

    Science.gov (United States)

    Zietz, Otto; Mylott, Elliot; Widenhorn, Ralf

    2015-01-01

    Planar x-ray imaging is a ubiquitous diagnostic tool and is routinely performed to diagnose conditions as varied as bone fractures and pneumonia. The underlying principle is that the varying attenuation coefficients of air, water, tissue, bone, or metal implants within the body result in non-uniform transmission of x-ray radiation. Through the…

  5. Trends and Technological Developments in Medical X-ray Imaging

    International Nuclear Information System (INIS)

    Iacobovici, E.; Ben-Shlomo, A.

    2004-01-01

    Since the very beginning of X-rays discovery, about one hundred years ago, there has been an ongoing development of technological means, focusing on image quality and imaging capabilities improvement, as well as on awareness and radiation dosage reduction

  6. Comparing neutron and X-ray images from NIF implosions

    Directory of Open Access Journals (Sweden)

    Wilson D.C.

    2013-11-01

    Full Text Available Directly laser driven and X-radiation driven DT filled capsules differ in the relationship between neutron and X-ray images. Shot N110217, a directly driven DT-filled glass micro-balloon provided the first neutron images at the National Ignition Facility. As seen in implosions on the Omega laser, the neutron image can be enclosed inside time integrated X-ray images. HYDRA simulations show the X-ray image is dominated by emission from the hot glass shell while the neutron image arises from the DT fuel it encloses. In the absence of mix or jetting, X-ray images of a cryogenically layered THD fuel capsule should be dominated by emission from the hydrogen rather than the cooler plastic shell that is separated from the hot core by cold DT fuel. This cool, dense DT, invisible in X-ray emission, shows itself by scattering hot core neutrons. Germanium X-ray emission spectra and Ross pair filtered X-ray energy resolved images suggest that germanium doped plastic emits in the torus shaped hot spot, probably reducing the neutron yield.

  7. From Relativistic Electrons to X-ray Phase Contrast Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A. H. [Fermilab; Garson, A. B. [Washington U., St. Louis; Anastasio, M. A. [Washington U., St. Louis

    2017-10-09

    We report the initial demonstrations of the use of single crystals in indirect x-ray imaging for x-ray phase contrast imaging at the Washington University in St. Louis Computational Bioimaging Laboratory (CBL). Based on single Gaussian peak fits to the x-ray images, we observed a four times smaller system point spread function (21 μm (FWHM)) with the 25-mm diameter single crystals than the reference polycrystalline phosphor’s 80-μm value. Potential fiber-optic plate depth-of-focus aspects and 33-μm diameter carbon fiber imaging are also addressed.

  8. Required doses for projection methods in X-ray diagnosis

    International Nuclear Information System (INIS)

    Hagemann, G.

    1992-01-01

    The ideal dose requirement has been stated by Cohen et al. (1981) by a formula basing on parallel beam, maximum quantum yield and Bucky grid effect depending on the signal to noise ratio and object contrast. This was checked by means of contrast detail diagrams measured at the hole phantom, and was additionally compared with measurement results obtained with acrylic glass phantoms. The optimal dose requirement is obtained by the maximum technically possible approach to the ideal requirement level. Examples are given, besides for x-ray equipment with Gd 2 O 2 S screen film systems for grid screen mammography, and new thoracic examination systems for mass screenings. Finally, a few values concerning the dose requirement or the analogous time required for fluorscent screening in angiography and interventional radiology, are stated, as well as for dentistry and paediatric x-ray diagnostics. (orig./HP) [de

  9. Collective radiation dose from diagnostic x-ray examination in nine ...

    African Journals Online (AJOL)

    Background: Medical x-ray exposures have the largest man made source of population exposure to ionizing radiation in different countries. Recent developments in medical imaging have led to rapid increases in a number of high dose xray examinations performed with significant consequences for individual patient doses ...

  10. Human genome sequencing with direct x-ray holographic imaging

    International Nuclear Information System (INIS)

    Rhodes, C.K.

    1993-01-01

    Direct holographic imaging of biological materials is widely applicable to the study of the structure, properties and action of genetic material. This particular application involves the sequencing of the human genome where prospective genomic imaging technology is composed of three subtechnologies, name an x-ray holographic camera, suitable chemistry and enzymology for the preparation of tagged DNA samples, and the illuminator in the form of an x-ray laser. We report appropriate x-ray camera, embodied by the instrument developed by MCR, is available and that suitable chemical and enzymatic procedures exist for the preparation of the necessary tagged DNA strands. Concerning the future development of the x-ray illuminator. We find that a practical small scale x-ray light source is indeed feasible. This outcome requires the use of unconventional physical processes in order to achieve the necessary power-compression in the amplifying medium. The understanding of these new physical mechanisms is developing rapidly. Importantly, although the x-ray source does not currently exist, the understanding of these new physical mechanisms is developing rapidly and the research has established the basic scaling laws that will determine the properties of the x-ray illuminator. When this x-ray source becomes available, an extremely rapid and cost effective instrument for 3-D imaging of biological materials can be applied to a wide range of biological structural assays, including the base-pair sequencing of the human genome and many questions regarding its higher levels of organization

  11. The measurement of patient doses from diagnostic x-rays

    International Nuclear Information System (INIS)

    Morris, N.D.; Solomon, S.B.

    1980-06-01

    As part of the National Health and Medical Research Council survey to determine the genetic and mean bone-marrow doses to the Australian population from the medical, dental and chiropractic uses of radiation sources, doses to patients undergoing X-ray diagnostic procedures were evaluated. The doses were measured using capsules of LiF or CaF 2 :Dy thermoluminescent dosemeters (TLD). The evaluation of the TLD measurements is described and the mean values of the skin doses for patients undergoing various radiographic examinations in Australia in 1970 are presented

  12. Hard X-ray Microscopic Imaging Of Human Breast Tissues

    Science.gov (United States)

    Park, Sung H.; Kim, Hong T.; Kim, Jong K.; Jheon, Sang H.; Youn, Hwa S.

    2007-01-01

    X-ray microscopy with synchrotron radiation will be a useful tool for innovation of x-ray imaging in clinical and laboratory settings. It helps us observe detailed internal structure of material samples non-invasively in air. And, it also has the potential to solve some tough problems of conventional breast imaging if it could evaluate various conditions of breast tissue effectively. A new hard x-ray microscope with a spatial resolution better than 100 nm was installed at Pohang Light Source, a third generation synchrotron radiation facility in Pohang, Korea. The x-ray energy was set at 6.95 keV, and the x-ray beam was monochromatized by W/B4C monochromator. Condenser and objective zone plates were used as x-ray lenses. Zernike phase plate next to condenser zone plate was introduced for improved contrast imaging. The image of a sample was magnified 30 times by objective zone plate and 20 times by microscope objective, respectively. After additional 10 times digital magnification, the total magnifying power was up to 6000 times in the end. Phase contrast synchrotron images of 10-μm-thick female breast tissue of the normal, fibroadenoma, fibrocystic change and carcinoma cases were obtained. By phase contrast imaging, hard x-rays enable us to observe many structures of breast tissue without sample preparations such as staining or fixation.

  13. Hard X-ray Microscopic Imaging Of Human Breast Tissues

    International Nuclear Information System (INIS)

    Park, Sung H.; Kim, Hong T.; Kim, Jong K.; Jheon, Sang H.; Youn, Hwa S.

    2007-01-01

    X-ray microscopy with synchrotron radiation will be a useful tool for innovation of x-ray imaging in clinical and laboratory settings. It helps us observe detailed internal structure of material samples non-invasively in air. And, it also has the potential to solve some tough problems of conventional breast imaging if it could evaluate various conditions of breast tissue effectively. A new hard x-ray microscope with a spatial resolution better than 100 nm was installed at Pohang Light Source, a third generation synchrotron radiation facility in Pohang, Korea. The x-ray energy was set at 6.95 keV, and the x-ray beam was monochromatized by W/B4C monochromator. Condenser and objective zone plates were used as x-ray lenses. Zernike phase plate next to condenser zone plate was introduced for improved contrast imaging. The image of a sample was magnified 30 times by objective zone plate and 20 times by microscope objective, respectively. After additional 10 times digital magnification, the total magnifying power was up to 6000 times in the end. Phase contrast synchrotron images of 10-μm-thick female breast tissue of the normal, fibroadenoma, fibrocystic change and carcinoma cases were obtained. By phase contrast imaging, hard x-rays enable us to observe many structures of breast tissue without sample preparations such as staining or fixation

  14. Performance of ultralow-dose CT with iterative reconstruction in lung cancer screening: limiting radiation exposure to the equivalent of conventional chest X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Adrian [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); University Hospital Pitie-Salpetriere, Department of Polyvalent and Oncological Radiology, Paris (France); Landau, Julia; Buetikofer, Yanik; Leidolt, Lars; Brela, Barbara; May, Michelle; Heverhagen, Johannes; Christe, Andreas [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); Ebner, Lukas [University Hospital Inselspital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); Duke University Medical Center, Department of Radiology, Durham, NC (United States)

    2016-10-15

    To investigate the detection rate of pulmonary nodules in ultralow-dose CT acquisitions. In this lung phantom study, 232 nodules (115 solid, 117 ground-glass) of different sizes were randomly distributed in a lung phantom in 60 different arrangements. Every arrangement was acquired once with standard radiation dose (100 kVp, 100 references mAs) and once with ultralow radiation dose (80 kVp, 6 mAs). Iterative reconstruction was used with optimized kernels: I30 for ultralow-dose, I70 for standard dose and I50 for CAD. Six radiologists examined the axial 1-mm stack for solid and ground-glass nodules. During a second and third step, three radiologists used maximum intensity projection (MIPs), finally checking with computer-assisted detection (CAD), while the others first used CAD, finally checking with the MIPs. The detection rate was 95.5 % with standard dose (DLP 126 mGy*cm) and 93.3 % with ultralow-dose (DLP: 9 mGy*cm). The additional use of either MIP reconstructions or CAD software could compensate for this difference. A combination of both MIP reconstructions and CAD software resulted in a maximum detection rate of 97.5 % with ultralow-dose. Lung cancer screening with ultralow-dose CT using the same radiation dose as a conventional chest X-ray is feasible. (orig.)

  15. Optical systems for synchrotron radiation: lecture 4. Soft x-ray imaging systems

    International Nuclear Information System (INIS)

    Howells, M.R.

    1986-04-01

    The history and present techniques of soft x-ray imaging are reviewed briefly. The physics of x-ray imaging is described, including the temporal and spatial coherence of x-ray sources. Particular technologies described are: contact x-ray microscopy, zone plate imaging, scanned image zone plate microscopy, scanned image reflection microscopy, and soft x-ray holography and diffraction

  16. X-ray and radioiodine dose to thyroid follicular cells

    International Nuclear Information System (INIS)

    Faw, R.E.

    1991-01-01

    Radiation doses to the epithelial cells of thyroid follicles have been calculated for internal exposure by radionuclides of iodine and by secondary radiations created as a result of interactions of externally administered x rays with iodine naturally occurring in the thyroid. Calculations were performed for the thyroids of subjects ranging from the newborn to the adult male. Results for internal radionuclides are reported as the dose rate to follicular-cell nuclei per unit specific activity of the radionuclide in the thyroid as a whole, i.e., as the specific ''S value'' as used in the MIRD method for internal dosimetry. Results for x rays are reported as the response function, i.e., the absorbed dose per unit fluence of primary x rays. Dose rates are subdivided into internal and external components, the former from radiations emitted within the colloid volume of any one follicle, and the latter from radiations emitted throughout the thyroid in follicles surrounding that one follicle. 37 refs., 5 figs., 3 tabs

  17. Optimisation in X-ray and Molecular Imaging 2015

    International Nuclear Information System (INIS)

    Baath, Magnus; Hoeschen, Christoph; Mattsson, Soeren; Mansson, Lars Gunnar

    2016-01-01

    This issue of Radiation Protection Dosimetry is based on contributions to Optimisation in X-ray and Molecular Imaging 2015 - the 4. Malmoe Conference on Medical Imaging (OXMI 2015). The conference was jointly organised by members of former and current research projects supported by the European Commission EURATOM Radiation Protection Research Programme, in cooperation with the Swedish Society for Radiation Physics. The conference brought together over 150 researchers and other professionals from hospitals, universities and industries with interests in different aspects of the optimisation of medical imaging. More than 100 presentations were given at this international gathering of medical physicists, radiologists, engineers, technicians, nurses and educational researchers. Additionally, invited talks were offered by world-renowned experts on radiation protection, spectral imaging and medical image perception, thus covering several important aspects of the generation and interpretation of medical images. The conference consisted of 13 oral sessions and a poster session, as reflected by the conference title connected by their focus on the optimisation of the use ionising radiation in medical imaging. The conference included technology-specific topics such as computed tomography and tomosynthesis, but also generic issues of interest for the optimisation of all medical imaging, such as image perception and quality assurance. Radiation protection was covered by e.g. sessions on patient dose benchmarking and occupational exposure. Technically-advanced topics such as modelling, Monte Carlo simulation, reconstruction, classification, and segmentation were seen taking advantage of recent developments of hardware and software, showing that the optimisation community is at the forefront of technology and adapts well to new requirements. These peer-reviewed proceedings, representing a continuation of a series of selected reports from meetings in the field of medical imaging

  18. On the limitations and optimisation of high-resolution 3D medical X-ray imaging systems

    International Nuclear Information System (INIS)

    Zhou Shuang; Brahme, Anders

    2011-01-01

    Based on a quantitative analysis of both attenuation and refractive properties of X-ray propagation in human body tissues and the introduction of a mathematical model for image quality analysis, some limitations and optimisation of high-resolution three-dimensional (3D) medical X-ray imaging techniques are studied. A comparison is made of conventional attenuation-based X-ray imaging methods with the phase-contrast X-ray imaging modalities that have been developed recently. The results indicate that it is theoretically possible through optimal design of the X-ray imaging system to achieve high spatial resolution (<100 μm) in 3D medical X-ray imaging of the human body at a clinically acceptable dose level (<10 mGy) by introducing a phase-contrast X-ray imaging technique.

  19. Benchtop phase-contrast X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gundogdu, O. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)], E-mail: o.gundogdu@surrey.ac.uk; Nirgianaki, E.; Che Ismail, E.; Jenneson, P.M.; Bradley, D.A. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2007-12-15

    Clinical radiography has traditionally been based on contrast obtained from absorption when X-rays pass through the body. The contrast obtained from traditional radiography can be rather poor, particularly when it comes to soft tissue. A wide range of media of interest in materials science, biology and medicine exhibit very weak absorption contrast, but they nevertheless produce significant phase shifts with X-rays. The use of phase information for imaging purposes is therefore an attractive prospect. Some of the X-ray phase-contrast imaging methods require highly monochromatic plane wave radiation and sophisticated X-ray optics. However, the propagation-based phase-contrast imaging method adapted in this paper is a relatively simple method to implement, essentially requiring only a microfocal X-ray tube and electronic detection. In this paper, we present imaging results obtained from two different benchtop X-ray sources employing the free space propagation method. X-ray phase-contrast imaging provides higher contrast in many samples, including biological tissues that have negligible absorption contrast.

  20. Absorbed dose assessment in newborns during x-ray examinations

    Science.gov (United States)

    Taipe, Patricia K.; Berrocal, Mariella J.; Carita, Raúl F.

    2012-02-01

    Often a newborn presents breathing problems during the early days of life, i.e. bronchopneumonia, wich are caused in most of cases, by aspirating a mixture of meconium and amniotic fluid. In these cases, it is necessary to make use of a radiograph, requested by the physician to reach a diagnosis. This paper seeks to evaluate the absorbed doses in neonates undergoing a radiograph. For this reason we try to simulate the real conditions in a X-ray room from Lima hospitals. With this finality we perform a simulation made according a questionnaire related to technical data of X-ray equipment, distance between the source and the neonate, and its position to be irradiated. The information obtained has been used to determine the absorbed dose by infants, using the MCNP code. Finally, the results are compared with reference values of international health agencies.

  1. Radiation Dose Measurements in Routine X Ray Examinations

    International Nuclear Information System (INIS)

    Osman, H.; Sulieman, A.; Suliman, I.I.; Sam, A.K.

    2011-01-01

    The aim of current study was to evaluate patients radiation dose in routine X-ray examinations in Omdurman teaching hospital Sudan.110 patients was examined (134) radiographs in two X-ray rooms. Entrance surface doses (ESDs) were calculated from patient exposure parameters using DosCal software. The mean ESD for the chest, AP abdomen, AP pelvis, thoracic spine AP, lateral lumber spine, anteroposterior lumber spine, lower limb and for the upper limb were; 231±44 Gy,453± 29 Gy, 567±22 Gy, 311±33 Gy,716±39 Gy, 611±55 Gy,311±23 Gy, and 158±57 Gy, respectively. Data shows asymmetry in distribution. The results of were comparable with previous study in Sudan.

  2. Effects of low X-ray doses in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Jordan, A.; Laskowski, W.

    1987-01-01

    Three strains of Saccharomyces cerevisiae with different capacities for repair of radiation damage (RAD, rad18, and rad52) have been tested for their colony forming ability (CFA) and growth rates after application of small X-ray doses from 3.8 mGy to 40 Gy. There was no reproducible increase in CFA observable after application of doses between 3.8 mGy and 4.7 Gy.X-ray doses of 40 Gy causing an inactivation of CFA from 90% to 50%, depending on the repair capacity of the strains used, caused a reduced increase in optical density during 2 h buffer treatment in comparison to unirradiated cells. This reduction however, is reversible as soon as the cells are transferred into nutrient medium. One hour after transfer into growh medium the portions of cells with large buds (Gs and M phase) and cells with small buds (S phase) are drastically different in irradiated cells from those obtained in unirradiated cells. The time necessary for separation of mother and daughter cells is prolonged by X-ray irradiation and the formation of new buds is retarded. (orig.)

  3. Characterizing Complexity of Containerized Cargo X-ray Images

    International Nuclear Information System (INIS)

    Wang, Guangxing; Martz, Harry; Glenn, Steven; Divin, Charles; Birrer, Nat

    2016-01-01

    X-ray imaging can be used to inspect cargos imported into the United States. In order to better understand the performance of X-ray inspection systems, the X-ray characteristics (density, complexity) of cargo need to be quantified. In this project, an image complexity measure called integrated power spectral density (IPSD) was studied using both DNDO engineered cargos and stream-of-commerce (SOC) cargos. A joint distribution of cargo density and complexity was obtained. A support vector machine was used to classify the SOC cargos into four categories to estimate the relative fractions.

  4. Characterizing Complexity of Containerized Cargo X-ray Images

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guangxing [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Martz, Harry [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glenn, Steven [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Divin, Charles [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Birrer, Nat [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-08-19

    X-ray imaging can be used to inspect cargos imported into the United States. In order to better understand the performance of X-ray inspection systems, the X-ray characteristics (density, complexity) of cargo need to be quantified. In this project, an image complexity measure called integrated power spectral density (IPSD) was studied using both DNDO engineered cargos and stream-of-commerce (SOC) cargos. A joint distribution of cargo density and complexity was obtained. A support vector machine was used to classify the SOC cargos into four categories to estimate the relative fractions.

  5. X-rays individual dose assessment using TLD dosimeters

    International Nuclear Information System (INIS)

    Salas, Carlos

    2008-01-01

    This paper describes the methodology used in Embalse NPP for measuring individual X-ray dose in dentists and radiologists, who work in areas near the plant. Personnel is provided with TLD personal dosimeters for thoracic use, as well as TLD ring dosimeters. This individual X-ray dosimetry is fundamental in order to know the effective energy coming from the radiation field, since the dosimetry factors depend on it. On the other hand, the response of the TLD crystals also depends of the effective energy; this accentuates the problem when assessing the individual dose. The X-ray dosimeter must simultaneously determine the value of the effective energy and the corresponding dose value. The basic principle for determining effective energy is by using at least two different TLD materials covered by filters of different thickness. The TLD materials used have totally energy responses. Therefore, different readouts from each of the crystals are obtained. The ratio between both readouts provides a factor that depends of the effective energy but that is 'independent' from the exposure values irradiated to the dosimeter. The Personal TLD dosimeter currently in use is Bicron-Harshaw. It comprises a carrier model 8807. This carrier contains a card model 2211 which groups two TLD 200 crystals and two TLD 100 crystals. It has internal filters at each side of the TLD 200 crystals. The periodical calibration of these dosimeters consists in the irradiation of some dosimeters with different X-ray energy beams in the National Atomic Energy Commission (CNEA). This dosimeter was used, by the National Regulatory Authority (ARN) in several comparisons, always getting satisfactory results. (author)

  6. GOES-12 Solar X-ray Imager Archive

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The GOES Solar X-ray Imager is integrated into the GOES-12 satellite, whose primary mission is to provide Earth-weather monitoring. The SXI is operated by NOAA's...

  7. Correction of ring artifacts in X-ray tomographic images

    DEFF Research Database (Denmark)

    Lyckegaard, Allan; Johnson, G.; Tafforeau, P.

    2011-01-01

    Ring artifacts are systematic intensity distortions located on concentric circles in reconstructed tomographic X-ray images. When using X-ray tomography to study for instance low-contrast grain boundaries in metals it is crucial to correct for the ring artifacts in the images as they may have...... the same intensity level as the grain boundaries and thus make it impossible to perform grain segmentation. This paper describes an implementation of a method for correcting the ring artifacts in tomographic X-ray images of simple objects such as metal samples where the object and the background...... are separable. The method is implemented in Matlab, it works with very little user interaction and may run in parallel on a cluster if applied to a whole stack of images. The strength and robustness of the method implemented will be demonstrated on three tomographic X-ray data sets: a mono-phase β...

  8. X-ray detectors based on image sensors

    International Nuclear Information System (INIS)

    Costa, A.P.R.

    1983-01-01

    X-ray detectors based on image sensors are described and a comparison is made between the advantages and the disadvantages of such a kind of detectors with the position sensitive detectors. (L.C.) [pt

  9. X-ray Computed Tomography Image Quality Indicator (IQI) Development

    Data.gov (United States)

    National Aeronautics and Space Administration — Phase one of the program is to identify suitable x-ray Computed Tomography (CT) Image Quality Indicator (IQI) design(s) that can be used to adequately capture CT...

  10. Tomographic image reconstruction using x-ray phase information

    Science.gov (United States)

    Momose, Atsushi; Takeda, Tohoru; Itai, Yuji; Hirano, Keiichi

    1996-04-01

    We have been developing phase-contrast x-ray computed tomography (CT) to make possible the observation of biological soft tissues without contrast enhancement. Phase-contrast x-ray CT requires for its input data the x-ray phase-shift distributions or phase-mapping images caused by an object. These were measured with newly developed fringe-scanning x-ray interferometry. Phase-mapping images at different projection directions were obtained by rotating the object in an x-ray interferometer, and were processed with a standard CT algorithm. A phase-contrast x-ray CT image of a nonstained cancerous tissue was obtained using 17.7 keV synchrotron x rays with 12 micrometer voxel size, although the size of the observation area was at most 5 mm. The cancerous lesions were readily distinguishable from normal tissues. Moreover, fine structures corresponding to cancerous degeneration and fibrous tissues were clearly depicted. It is estimated that the present system is sensitive down to a density deviation of 4 mg/cm3.

  11. Quality criteria for chest X-ray image

    International Nuclear Information System (INIS)

    Krieg, R.

    1985-01-01

    A distinction has to be made between invariable and variable criteria in the determination of chest X-ray picture quality criteria. The invariable criteria are defined by the properties of the object and the psychophysiological laws of perception and cognition, and the variable criteria are determined by the prevailing state of the art of technology. An agreement on these criteria is based on the knowledge of the nature and the technical conditions of X-ray picture production and reproduction. The slogan 'the best picture at the lowest dose' dominates, too, the discussion centering around the X-ray picture of the chest, its quality and criteria. (orig./MG) [de

  12. Ghost imaging with paired x-ray photons

    Science.gov (United States)

    Schori, A.; Borodin, D.; Tamasaku, K.; Shwartz, S.

    2018-06-01

    We report the experimental observation of ghost imaging with paired x-ray photons, which are generated by parametric downconversion. We use the one-to-one relation between the photon energies and the emission angles and the anticorrelation between the k -vectors of the signal and the idler photons to reconstruct the images of slits with nominally zero background levels. Further extension of our procedure can be used for the observation of various quantum phenomena at x-ray wavelengths.

  13. Improvements in x-ray image converters and phosphors

    International Nuclear Information System (INIS)

    Rabatin, J.G.

    1981-01-01

    Improvements to an X-ray image converter comprising crystals of rare earth phosphor admixtures are described. The phosphor admixtures utilize thulium-activated lanthanum and/or gadolinium oxyhalide phosphor material to increase the relative speed and resolution of an X-ray image compared with conventional rare earth phosphors. Examples of various radiographic screens containing one or more of the phosphor materials are given. (U.K.)

  14. The Effects on Absorbed Dose Distribution in Intraoral X-ray Imaging When Using Tube Voltages of 60 and 70 kV for Bitewing Imaging

    Directory of Open Access Journals (Sweden)

    Kristina Hellén-Halme

    2013-10-01

    Full Text Available Objectives: Efforts are made in radiographic examinations to obtain the best image quality with the lowest possible absorbed dose to the patient. In dental radiography, the absorbed dose to patients is very low, but exposures are relatively frequent. It has been suggested that frequent low-dose exposures can pose a risk for development of future cancer. It has previously been reported that there was no significant difference in the diagnostic accuracy of approximal carious lesions in radiographs obtained using tube voltages of 60 and 70 kV. The aim of this study was, therefore, to evaluate the patient dose resulting from exposures at these tube voltages to obtain intraoral bitewing radiographs.Material and Methods: The absorbed dose distributions resulting from two bitewing exposures were measured at tube voltages of 60 and 70 kV using Gafchromic® film and an anatomical head phantom. The dose was measured in the occlusal plane, and ± 50 mm cranially and caudally to evaluate the amount of scattered radiation. The same entrance dose to the phantom was used. The absorbed dose was expressed as the ratio of the maximal doses, the mean doses and the integral doses at tube voltages of 70 and 60 kV.Results: The patient receives approximately 40 - 50% higher (mean and integral absorbed dose when a tube voltage of 70 kV is used.Conclusions: The results of this study clearly indicate that 60 kV should be used for dental intraoral radiographic examinations for approximal caries detection.

  15. Ultrafast secondary emission x-ray imaging detectors

    International Nuclear Information System (INIS)

    Akkerman, A.; Gibrekhterman, A.; Majewski, S.

    1991-07-01

    Fast high accuracy, x-ray imaging at high photon flux can be achieved when coupling thin solid convertors to gaseous electron multipliers, operating at low gas pressures. Secondary electron emitted from the convertor foil are multiplied in several successive amplification elements. The obvious advantage of solid x-ray detectors, as compared to gaseous conversion, are the production of parallax-free images and the fast (subnanoseconds) response. These x-ray detectors have many potential applications in basic and applied research. Of particular interest is the possibility of an efficient and ultrafast high resolution imaging of transition radiation,with a reduced dE/dx background. We present experimental results on the operation of the secondary emission x-ray (SEX) detectors, their detection efficiency, localization and time resolution. The experimental work is accompanied by mathematical modelling and computer simulation of transition radiation detectors based on CsI transition radiation convertors. (author)

  16. Real-time digital X-ray subtraction imaging

    International Nuclear Information System (INIS)

    Mistretta, C.A.; Kruger, R.A.; Houk, T.L.

    1979-01-01

    A diagnostic anatomical X-ray apparatus comprising a converter and a television camera for converting an X-ray image of a subject into a series of television fields of video signals is described in detail. A digital memory system stores and integrates the video signals over a time interval corresponding to a plurality of successive television fields. The integrated video signals are recovered from storage and fed to a digital or analogue subtractor, the resulting output being displayed on a television monitor. Thus the display represents on-going changes in the anatomical X-ray image. In a modification, successive groups of fields are stored and integrated in three memories, cyclically, and subtractions are performed between successive pieces of integrated signals to provide a display of successive alterations in the X-ray image. For investigations of the heart, the integrating interval should be of the order of one cardiac cycle. (author)

  17. Translate rotate scanning method for X-ray imaging

    International Nuclear Information System (INIS)

    Eberhard, J.W.; Kwog Cheong Tam.

    1990-01-01

    Rapid x-ray inspection of objects larger than an x-ray detector array is based on a translate rotate scanning motion of the object related to the fan beam source and detector. The scan for computerized tomography imaging is accomplished by rotating the object through 360 degrees at two or more positions relative to the source and detector array, in moving to another position the object is rotated and the object or source and detector are translated. A partial set of x-ray data is acquired at every position which are combined to obtain a full data set for complete image reconstruction. X-ray data for digital radiography imaging is acquired by scanning the object vertically at a first position at one view angle, rotating and translating the object relative to the source and detector to a second position, scanning vertically, and so on to cover the object field of view, and combining the partial data sets. (author)

  18. Dose calculation of X-ray in medium

    International Nuclear Information System (INIS)

    Liu Yanmei; Xue Dingyu; Xu Xinhe; Chen Zhen; Dong Zaili

    2006-01-01

    The photon transportation in radiotherapy is studied based on Monte Carlo method. The dose calculation based on the MC simulation package DPM has been carried out, and the results have been visualized using MEX technology of Matlab. The dose results of X-ray in homogeneity and inhomogeneity medium have been compared with experimental data and those of other MC simulation package, and these results all agree. The calculation method we proposed has the advantage of high speed and good accuracy, therefore, is applicable in practice. (authors)

  19. Assessment of image quality in x-ray radiography imaging using a small plasma focus device

    International Nuclear Information System (INIS)

    Kanani, A.; Shirani, B.; Jabbari, I.; Mokhtari, J.

    2014-01-01

    This paper offers a comprehensive investigation of image quality parameters for a small plasma focus as a pulsed hard x-ray source for radiography applications. A set of images were captured from some metal objects and electronic circuits using a low energy plasma focus at different voltages of capacitor bank and different pressures of argon gas. The x-ray source focal spot of this device was obtained to be about 0.6 mm using the penumbra imaging method. The image quality was studied by several parameters such as image contrast, line spread function (LSF) and modulation transfer function (MTF). Results showed that the contrast changes by variations in gas pressure. The best contrast was obtained at a pressure of 0.5 mbar and 3.75 kJ stored energy. The results of x-ray dose from the device showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. The measurements of LSF and MTF parameters were carried out by means of a thin stainless steel wire 0.8 mm in diameter and the cut-off frequency was obtained to be about 1.5 cycles/mm. - Highlights: • We investigated a small plasma focus as pulsed x-ray source for radiography applications. • The image quality was studied by several parameters such as image contrast, LSF and MTF. • The x-ray source focal spot was obtained to be ∼0.6 mm using the penumbra imaging method. • The x-ray dose measurement showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. • The profiles of LSF and MTF showed that the cut-off frequency is about 1.5 cycles/mm

  20. Calibrating the Regolith X-ray Imaging Spectrometer (REXIS)

    OpenAIRE

    McIntosh, Missy; Hong, Jaesub; Allen, Branden; Grindlay, Jonathan

    2014-01-01

    This paper describes the onboard calibration process of REXIS (the Regolith X-ray Imaging Spectrometer), an instrument on OSIRIS-REx. OSIRIS-REx, scheduled to be launched in 2016, is a planetary mission intending to return a regolith sample from a near Earth asteroid called Bennu. REXIS, a student-led collaboration between Harvard and MIT, is a soft X-ray (0.5-7.5 keV) coded-aperture telescope with four X-ray CCDs and a gold coated stainless steel mask. REXIS will measure the surface elementa...

  1. A survey of chest medical X-ray doses

    International Nuclear Information System (INIS)

    Lomba, M.; Conha, P.G. da; Almeida, C.E. de

    1996-01-01

    The medical X-ray exposures due to radiological examinations are responsible for the largest contribution to the population collective dose as result of the normal use of artificial sources of radiation. The relative impact of the medical exposures to the total dose received by the population from all kinds of radiation sources varies from country to country and in some cases within the same country. The dose variations observed for a specific type of examination are in general associated to several factors i.e. the type of film-ecran combination, the choice of the appropriate physical parameters of the X-ray generator (Kvp, filament current, exposure time) and finally to the film processing conditions. At the present moment the data available in Brazil are scarce and scanty to allow a complete analyzis of this question so needed by the health authorities to justify the implementation of a quality assurance and dose reduction programs. In addition, it is desirable to establish a cost effective operation based on simple administrative concepts in order to reduce the number of films retake, then increasing the life expectancy of the equipment and the number of radiological procedures. The aim of this work was to assess the typical doses of an PA and LAT chest wall X-ray examinations in five different public hospitals (a University Hospital, a Cancer Hospital, a Navy Hospital, an Emergency Hospital and a State General Hospital), as representative of the city of Rio de Janeiro, and compare the results with the international data and recommendations available. (author)

  2. Determination of Entrance Skin Doses and Organ Doses for Medical X Ray Examinations

    International Nuclear Information System (INIS)

    Tung, C.J.; Cheng, C.Y.; Chao, T.C.; Tsai, H.Y.

    1999-01-01

    A national survey of patient doses for diagnostic X ray radiographs is planned in Taiwan. Entrance skin doses and organ doses for all installed X ray machines will be investigated. A pilot study has been carried out for the national survey to develop a protocol for the dose assessment. Entrance skin doses and organ doses were measured by thermoluminescence dosemeters and calculated by Monte Carlo simulations for several X ray examinations. The conversion factor from free air entrance absorbed dose to entrance skin dose was derived. A formula for the computation of entrance skin doses from inputs of kV p , mA.s, source to skin distance, aluminium filtration, and generator rectifying was constructed. Organ doses were measured using a RANDO phantom and calculated using a mathematical phantom. All data will be passed to the Atomic Energy Council for developing a programme of national survey and regulatory controls for diagnostic X ray examinations. (author)

  3. Spectroscopic imaging, diffraction, and holography with x-ray photoemission

    International Nuclear Information System (INIS)

    1992-02-01

    X-ray probes are capable of determining the spatial structure of an atom in a specific chemical state, over length scales from about a micron all the way down to atomic resolution. Examples of these probes include photoemission microscopy, energy-dependent photoemission diffraction, photoelectron holography, and X-ray absorption microspectroscopy. Although the method of image formation, chemical-state sensitivity, and length scales can be very different, these X-ray techniques share a common goal of combining a capability for structure determination with chemical-state specificity. This workshop will address recent advances in holographic, diffraction, and direct imaging techniques using X-ray photoemission on both theoretical and experimental fronts. A particular emphasis will be on novel structure determinations with atomic resolution using photoelectrons

  4. Spectroscopic imaging, diffraction, and holography with x-ray photoemission

    Energy Technology Data Exchange (ETDEWEB)

    1992-02-01

    X-ray probes are capable of determining the spatial structure of an atom in a specific chemical state, over length scales from about a micron all the way down to atomic resolution. Examples of these probes include photoemission microscopy, energy-dependent photoemission diffraction, photoelectron holography, and X-ray absorption microspectroscopy. Although the method of image formation, chemical-state sensitivity, and length scales can be very different, these X-ray techniques share a common goal of combining a capability for structure determination with chemical-state specificity. This workshop will address recent advances in holographic, diffraction, and direct imaging techniques using X-ray photoemission on both theoretical and experimental fronts. A particular emphasis will be on novel structure determinations with atomic resolution using photoelectrons.

  5. High-speed image converter x-ray studies

    International Nuclear Information System (INIS)

    Bryukhnevitch, G.I.; Kas'yanov, Yu.S.; Korobkin, V.V.; Prokhorov, A.M.; Stepanov, B.M.; Chevokin, V.K.; Schelev, M.Ya.

    1975-01-01

    Two X-ray high-speed image-converter cameras (ICC) have been developed. In the first one a soft X-ray radiation is converted into visible light with the aid of a 0.5ns response time, plastic scintillator. The second camera incorporates a photocathode which is sensitive to visible and X-ray radiation. Its calculated temporal resolution approaches 5 to 7ps. Both developed cameras were employed for studies of X-ray radiation emitted by laser plasma. For the smooth nanosecond excited laser pulses, a noticeable amplitude modulation was recorded in all laser pulses reflected by plasma as well as in each third pulse of X-ray plasma radiation. It was also observed that the duration of X-ray plasma radiation is 20 to 40% shorter than that of the incident nanosecond laser pulses and this duration being 3 to 6 times longer than that of the picosecond irradiating pulses. The half-width of the recorded X-ray plasma pulses was 30 to 60ps. (author)

  6. X-ray imaging using digital cameras

    Science.gov (United States)

    Winch, Nicola M.; Edgar, Andrew

    2012-03-01

    The possibility of using the combination of a computed radiography (storage phosphor) cassette and a semiprofessional grade digital camera for medical or dental radiography is investigated. We compare the performance of (i) a Canon 5D Mk II single lens reflex camera with f1.4 lens and full-frame CMOS array sensor and (ii) a cooled CCD-based camera with a 1/3 frame sensor and the same lens system. Both systems are tested with 240 x 180 mm cassettes which are based on either powdered europium-doped barium fluoride bromide or needle structure europium-doped cesium bromide. The modulation transfer function for both systems has been determined and falls to a value of 0.2 at around 2 lp/mm, and is limited by light scattering of the emitted light from the storage phosphor rather than the optics or sensor pixelation. The modulation transfer function for the CsBr:Eu2+ plate is bimodal, with a high frequency wing which is attributed to the light-guiding behaviour of the needle structure. The detective quantum efficiency has been determined using a radioisotope source and is comparatively low at 0.017 for the CMOS camera and 0.006 for the CCD camera, attributed to the poor light harvesting by the lens. The primary advantages of the method are portability, robustness, digital imaging and low cost; the limitations are the low detective quantum efficiency and hence signal-to-noise ratio for medical doses, and restricted range of plate sizes. Representative images taken with medical doses are shown and illustrate the potential use for portable basic radiography.

  7. Advanced imaging technology using carbon nanotube x ray source

    International Nuclear Information System (INIS)

    Choi, Hae Young; Seol, Seung Kown; Kim, Jaehoon; Yoo, Seung Hoon; Kim, Jong Uk

    2008-01-01

    Recently, X ray imaging technology is a useful and leading medical diagnostic tool for healthcare professionals to diagnose disease in human body. CNTs(i.e. carbon nanotubes)are used in many applications like FED, Micro wave amplifier, X ray source, etc. because of its suitable electrical, chemical and physical properties. Specially, CNTs are well used electron emitters for x ray source. Conventionally, thermionic type of tungsten filament x ray tube is widely employed in the field of bio medical and industrial application fields. However, intrinsic problems such as, poor emission efficiency and low imaging resolution cause the limitation of use of the x ray tube. To fulfill the current market requirement specifically for medical diagnostic field, we have developed rather a portable and compact CNT based x ray source in which high imaging resolution is provided. Electron sources used in X ray tubes should be well focused to the anode target for generation of high quality x ray. In this study, Pierce type x ray generation module was tested based its simulation results using by OPERA 3D code. Pierce type module is composed of cone type electrical lens with its number of them and inner angles of them that shows different results with these parameters. And some preliminary images obtained using the CNT x ray source were obtained. The represented images are the finger bone and teeth in human body. It is clear that the trabeculation shape is observed in finger bone. To obtain the finger bone image, tube currents of 250A at 42kV tube voltage was applied. The human tooth image, however, is somewhat unclear because the supplied voltage to the tube was limited to max. 50kV in the system developed. It should be noted that normally 60∼70kV of tube voltage is supplied in dental imaging. Considering these it should be emphasized that if the tube voltage is over 60kV then clearer image is possible. In this paper, we are discussed comparing between these experiment results and

  8. Device for congruent X-ray images of teeth

    International Nuclear Information System (INIS)

    Wegner, H.; Zeumer, H.

    1987-01-01

    This invention has to do with a device for congruent X-ray images of teeth by means of the long-tube parallel technique and the long-tube semi-angle technique. The aim is to have no disturbing lever forces in order to avoid mechanical tensions between patient and X-ray tube assembly and to achieve a true projection of teeth and jaw-bone part also under unfavourable anatomical conditions

  9. Pixel detectors for x-ray imaging spectroscopy in space

    International Nuclear Information System (INIS)

    Treis, J; Andritschke, R; Hartmann, R; Herrmann, S; Holl, P; Lauf, T; Lechner, P; Lutz, G; Meidinger, N; Porro, M; Richter, R H; Schopper, F; Soltau, H; Strueder, L

    2009-01-01

    Pixelated semiconductor detectors for X-ray imaging spectroscopy are foreseen as key components of the payload of various future space missions exploring the x-ray sky. Located on the platform of the new Spectrum-Roentgen-Gamma satellite, the eROSITA (extended Roentgen Survey with an Imaging Telescope Array) instrument will perform an imaging all-sky survey up to an X-ray energy of 10 keV with unprecedented spectral and angular resolution. The instrument will consist of seven parallel oriented mirror modules each having its own pnCCD camera in the focus. The satellite born X-ray observatory SIMBOL-X will be the first mission to use formation-flying techniques to implement an X-ray telescope with an unprecedented focal length of around 20 m. The detector instrumentation consists of separate high- and low energy detectors, a monolithic 128 x 128 DEPFET macropixel array and a pixellated CdZTe detector respectively, making energy band between 0.5 to 80 keV accessible. A similar concept is proposed for the next generation X-ray observatory IXO. Finally, the MIXS (Mercury Imaging X-ray Spectrometer) instrument on the European Mercury exploration mission BepiColombo will use DEPFET macropixel arrays together with a small X-ray telescope to perform a spatially resolved planetary XRF analysis of Mercury's crust. Here, the mission concepts and their scientific targets are briefly discussed, and the resulting requirements on the detector devices together with the implementation strategies are shown.

  10. Pixel detectors for x-ray imaging spectroscopy in space

    Science.gov (United States)

    Treis, J.; Andritschke, R.; Hartmann, R.; Herrmann, S.; Holl, P.; Lauf, T.; Lechner, P.; Lutz, G.; Meidinger, N.; Porro, M.; Richter, R. H.; Schopper, F.; Soltau, H.; Strüder, L.

    2009-03-01

    Pixelated semiconductor detectors for X-ray imaging spectroscopy are foreseen as key components of the payload of various future space missions exploring the x-ray sky. Located on the platform of the new Spectrum-Roentgen-Gamma satellite, the eROSITA (extended Roentgen Survey with an Imaging Telescope Array) instrument will perform an imaging all-sky survey up to an X-ray energy of 10 keV with unprecedented spectral and angular resolution. The instrument will consist of seven parallel oriented mirror modules each having its own pnCCD camera in the focus. The satellite born X-ray observatory SIMBOL-X will be the first mission to use formation-flying techniques to implement an X-ray telescope with an unprecedented focal length of around 20 m. The detector instrumentation consists of separate high- and low energy detectors, a monolithic 128 × 128 DEPFET macropixel array and a pixellated CdZTe detector respectively, making energy band between 0.5 to 80 keV accessible. A similar concept is proposed for the next generation X-ray observatory IXO. Finally, the MIXS (Mercury Imaging X-ray Spectrometer) instrument on the European Mercury exploration mission BepiColombo will use DEPFET macropixel arrays together with a small X-ray telescope to perform a spatially resolved planetary XRF analysis of Mercury's crust. Here, the mission concepts and their scientific targets are briefly discussed, and the resulting requirements on the detector devices together with the implementation strategies are shown.

  11. Pixel detectors for x-ray imaging spectroscopy in space

    Energy Technology Data Exchange (ETDEWEB)

    Treis, J; Andritschke, R; Hartmann, R; Herrmann, S; Holl, P; Lauf, T; Lechner, P; Lutz, G; Meidinger, N; Porro, M; Richter, R H; Schopper, F; Soltau, H; Strueder, L [MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, D-81739 Munich (Germany)], E-mail: jft@hll.mpg.de

    2009-03-15

    Pixelated semiconductor detectors for X-ray imaging spectroscopy are foreseen as key components of the payload of various future space missions exploring the x-ray sky. Located on the platform of the new Spectrum-Roentgen-Gamma satellite, the eROSITA (extended Roentgen Survey with an Imaging Telescope Array) instrument will perform an imaging all-sky survey up to an X-ray energy of 10 keV with unprecedented spectral and angular resolution. The instrument will consist of seven parallel oriented mirror modules each having its own pnCCD camera in the focus. The satellite born X-ray observatory SIMBOL-X will be the first mission to use formation-flying techniques to implement an X-ray telescope with an unprecedented focal length of around 20 m. The detector instrumentation consists of separate high- and low energy detectors, a monolithic 128 x 128 DEPFET macropixel array and a pixellated CdZTe detector respectively, making energy band between 0.5 to 80 keV accessible. A similar concept is proposed for the next generation X-ray observatory IXO. Finally, the MIXS (Mercury Imaging X-ray Spectrometer) instrument on the European Mercury exploration mission BepiColombo will use DEPFET macropixel arrays together with a small X-ray telescope to perform a spatially resolved planetary XRF analysis of Mercury's crust. Here, the mission concepts and their scientific targets are briefly discussed, and the resulting requirements on the detector devices together with the implementation strategies are shown.

  12. Dilation x-ray imager a new∕faster gated x-ray imager for the NIF.

    Science.gov (United States)

    Nagel, S R; Hilsabeck, T J; Bell, P M; Bradley, D K; Ayers, M J; Barrios, M A; Felker, B; Smith, R F; Collins, G W; Jones, O S; Kilkenny, J D; Chung, T; Piston, K; Raman, K S; Sammuli, B; Hares, J D; Dymoke-Bradshaw, A K L

    2012-10-01

    As the yield on implosion shots increases it is expected that the peak x-ray emission reduces to a duration with a FWHM as short as 20 ps for ∼7 × 10(18) neutron yield. However, the temporal resolution of currently used gated x-ray imagers on the NIF is 40-100 ps. We discuss the benefits of the higher temporal resolution for the NIF and present performance measurements for dilation x-ray imager, which utilizes pulse-dilation technology [T. J. Hilsabeck et al., Rev. Sci. Instrum. 81, 10E317 (2010)] to achieve x-ray imaging with temporal gate times below 10 ps. The measurements were conducted using the COMET laser, which is part of the Jupiter Laser Facility at the Lawrence Livermore National Laboratory.

  13. Dilation x-ray imager a new/faster gated x-ray imager for the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, S. R.; Bell, P. M.; Bradley, D. K.; Ayers, M. J.; Barrios, M. A.; Felker, B.; Smith, R. F.; Collins, G. W.; Jones, O. S.; Piston, K.; Raman, K. S. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Hilsabeck, T. J.; Kilkenny, J. D.; Chung, T.; Sammuli, B. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Hares, J. D.; Dymoke-Bradshaw, A. K. L. [Kentech Instruments Ltd., Wallingford, Oxfordshire OX10 (United Kingdom)

    2012-10-15

    As the yield on implosion shots increases it is expected that the peak x-ray emission reduces to a duration with a FWHM as short as 20 ps for {approx}7 Multiplication-Sign 10{sup 18} neutron yield. However, the temporal resolution of currently used gated x-ray imagers on the NIF is 40-100 ps. We discuss the benefits of the higher temporal resolution for the NIF and present performance measurements for dilation x-ray imager, which utilizes pulse-dilation technology [T. J. Hilsabeck et al., Rev. Sci. Instrum. 81, 10E317 (2010)] to achieve x-ray imaging with temporal gate times below 10 ps. The measurements were conducted using the COMET laser, which is part of the Jupiter Laser Facility at the Lawrence Livermore National Laboratory.

  14. SU-F-J-52: A Novel Approach to X-Ray Tube Quality Assurance for CBCT Systems in Order to Better Assess the Patient Imaging Dose in a Large, Multi-Unit Treatment Facility

    International Nuclear Information System (INIS)

    Buckley, L; Lambert, C; Nyiri, B; Gerig, L; Webb, R

    2016-01-01

    Purpose: To standardize the tube calibration for Elekta XVI cone beam CT (CBCT) systems in order to provide a meaningful estimate of the daily imaging dose and reduce the variation between units in a large centre with multiple treatment units. Methods: Initial measurements of the output from the CBCT systems were made using a Farmer chamber and standard CTDI phantom. The correlation between the measured CTDI and the tube current was confirmed using an Unfors Xi detector which was then used to perform a tube current calibration on each unit. Results: Initial measurements showed measured tube current variations of up to 25% between units for scans with the same image settings. In order to reasonably estimate the imaging dose, a systematic approach to x-ray generator calibration was adopted to ensure that the imaging dose was consistent across all units at the centre and was adopted as part of the routine quality assurance program. Subsequent measurements show that the variation in measured dose across nine units is on the order of 5%. Conclusion: Increasingly, patients receiving radiation therapy have extended life expectancies and therefore the cumulative dose from daily imaging should not be ignored. In theory, an estimate of imaging dose can be made from the imaging parameters. However, measurements have shown that there are large differences in the x-ray generator calibration as installed at the clinic. Current protocols recommend routine checks of dose to ensure constancy. The present study suggests that in addition to constancy checks on a single machine, a tube current calibration should be performed on every unit to ensure agreement across multiple machines. This is crucial at a large centre with multiple units in order to provide physicians with a meaningful estimate of the daily imaging dose.

  15. SU-F-J-52: A Novel Approach to X-Ray Tube Quality Assurance for CBCT Systems in Order to Better Assess the Patient Imaging Dose in a Large, Multi-Unit Treatment Facility

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, L; Lambert, C; Nyiri, B; Gerig, L [The Ottawa Hospital Cancer Ctr., Ottawa, ON (Canada); Webb, R [Elekta, Montreal, Quebec (Canada)

    2016-06-15

    Purpose: To standardize the tube calibration for Elekta XVI cone beam CT (CBCT) systems in order to provide a meaningful estimate of the daily imaging dose and reduce the variation between units in a large centre with multiple treatment units. Methods: Initial measurements of the output from the CBCT systems were made using a Farmer chamber and standard CTDI phantom. The correlation between the measured CTDI and the tube current was confirmed using an Unfors Xi detector which was then used to perform a tube current calibration on each unit. Results: Initial measurements showed measured tube current variations of up to 25% between units for scans with the same image settings. In order to reasonably estimate the imaging dose, a systematic approach to x-ray generator calibration was adopted to ensure that the imaging dose was consistent across all units at the centre and was adopted as part of the routine quality assurance program. Subsequent measurements show that the variation in measured dose across nine units is on the order of 5%. Conclusion: Increasingly, patients receiving radiation therapy have extended life expectancies and therefore the cumulative dose from daily imaging should not be ignored. In theory, an estimate of imaging dose can be made from the imaging parameters. However, measurements have shown that there are large differences in the x-ray generator calibration as installed at the clinic. Current protocols recommend routine checks of dose to ensure constancy. The present study suggests that in addition to constancy checks on a single machine, a tube current calibration should be performed on every unit to ensure agreement across multiple machines. This is crucial at a large centre with multiple units in order to provide physicians with a meaningful estimate of the daily imaging dose.

  16. Dose reduction by x-ray beam filtration in screen-film radiography

    International Nuclear Information System (INIS)

    Koedooder, C.

    1986-01-01

    This thesis describes experimental and theoretical aspects of dose reduction by x-ray beam filtration in screen-film radiography. The thesis deals mainly with dose reduction under the constraint of constant image quality; an analytical approach is chosen. Therefore, part of the thesis deals with the development of an algorithm to calculate patient dose and exposure for different filter materials and different tube load conditions, under the constraint of constant contrast and constant optical density. (Auth.)

  17. Spectral and imaging characterization of tabletop X-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J.; Osterheld, A.L.; Moon, S.J.; Fournier, K.B.; Nilsen, J. [Lawrence Livermore National Lab., CA (United States); Faenov, A.Ya.; Pikuz, T.A.; Skobelev, I.Yu.; Magunov, A.I. [Lawrence Livermore National Lab., CA (United States); MISDC of VNIIFTRI, Mendeleevo (Russian Federation); Shlyaptsev, V.N. [Lawrence Livermore National Lab., CA (United States); California Univ., Davis, CA (United States). DAS

    2001-07-01

    We have performed L-shell spectroscopy and one-dimensional (1-D) imaging of a line focus plasma from a laser-heated Fe polished slab using the tabletop COMET laser system at the Lawrence Livermore National Laboratory. These plasmas are used to generate a Ne-like Fe transient gain X-ray laser that is recorded simultaneously. A spherically-curved crystal spectrometer gives high resolution X-ray spectra of the n=3-2 and n=4-2 resonance lines with 1-D spatial resolution along the line focus. Spectra are presented for different laser pulse conditions. In addition, a variety of X-ray imaging techniques are described. We discuss imaging results from a double-slit X-ray camera with a spherically-curved crystal spectrometer. We show a high resolution Fe K-{alpha} spectrum from the X-ray laser target that indicates the presence of hot electrons in the X-ray laser plasma. (orig.)

  18. Real-time digital x-ray subtraction imaging

    International Nuclear Information System (INIS)

    Mistretta, C.A.

    1982-01-01

    The invention provides a method of producing visible difference images derived from an X-ray image of an anatomical subject, comprising the steps of directing X-rays through the anatomical subject for producing an image, converting the image into television fields comprising trains of on-going video signals, digitally storing and integrating the on-going video signals over a time interval corresponding to several successive television fields and thereby producing stored and integrated video signals, recovering the video signals from storage and producing integrated video signals, producing video difference signals by performing a subtraction between the integrated video signals and the on-going video signals outside the time interval, and converting the difference signals into visible television difference images representing on-going changes in the X-ray image

  19. Patient doses due to a diagnostic X-ray picture

    International Nuclear Information System (INIS)

    Riet, A. van 't.

    1977-09-01

    The influence of technical parameters on patient doses in X-ray diagnostics has been investigated. During an X-ray picture (30 x 40 or 35 x 43 cm 2 ) for general survey in intraveneous pyelography (IVP), skin exposure measurements in the centre of the radiation beam were carried out at 650 adult female patients in 46 Dutch hospitals. In addition, the first half-value layer of the radiation was measured. In 15 of these hospitals, similar measurements were also carried out at a Rando phantom. Small LiF thermoluminescent dosemeters were used for all measurements. The results show a remarkable variation in the mean entrance- and exit-exposure per hospital. The variation in the mean entrance-exposure per hospital (factor 8) is mainly caused by differences in radiation quality. In some hospitals, no added filtration is used while others use a relatively heavy filtration. The variation in the mean exit-exposure per hospital could not be explained uniquely from technical parameters like grid, screen and film sensivity. From phantom measurements it was found that other parameters like adjustment of the automatic exposure timer and film density required by the radiographer are of importance. The measuring system used has shown to be an adequate and simple tool for a crude selection of those hospitals where skin exposures are relatively high. On the basis of the collected data some recommendations are given to promote dose reduction in X-ray diagnostics. The use of fast screen-film combinations is of great potential importance. However further investigation seems desirable, especially concerning patient dose during fluoroscopy 0

  20. Assessment of organ doses by standard X-ray procedures in the GDR

    International Nuclear Information System (INIS)

    Tautz, M.; Brandt, G.A.

    1986-01-01

    A modern method has been described to assess the radiation burden by X-ray procedures with consideration of the standards of our Society for Medical Radiology in the GDR. The underlying methodology is a Monte Carlo computer technique, which simulates stochastically the energy deposition of X-ray photons in a mathematically described heterogeneous anthropomorphic phantom by Rosenstein (US Department of Health, Education and Welfare). To apply the procedure specific values for the following parameters must be determined for each dose estimation: projection and view, X-ray field size and location entrance exposure at skin surface, beam quality, source-to-image receptor distance. The base data are obtained in terms of tissue-air ratio. Organ doses were calculated for chest, urography, skull, cervical spine, thoracic spine, lumbar spine, pelvis and lymphography. Concluding possibilities have been discussed for reduction of radiation burden. 9 refs., 6 figs., 9 tabs. (author)

  1. Low-dose phase contrast tomography with conventional x-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, C. K., E-mail: charlotte.hagen.10@ucl.ac.uk; Endrizzi, M.; Diemoz, P. C.; Olivo, A. [Department of Medical Physics and Bioengineering, University College London, Malet Place, Gower Street, London WC1E 6BT (United Kingdom); Munro, P. R. T. [Optical + Biomedical Engineering Laboratory, School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia and Centre for Microscopy, Characterisation, and Analysis, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009 (Australia)

    2014-07-15

    Purpose: The edge illumination (EI) x-ray phase contrast imaging (XPCi) method has been recently further developed to perform tomographic and, thus, volumetric imaging. In this paper, the first tomographic EI XPCi images acquired with a conventional x-ray source at dose levels below that used for preclinical small animal imaging are presented. Methods: Two test objects, a biological sample and a custom-built phantom, were imaged with a laboratory-based EI XPCi setup in tomography mode. Tomographic maps that show the phase shift and attenuating properties of the object were reconstructed, and analyzed in terms of signal-to-noise ratio and quantitative accuracy. Dose measurements using thermoluminescence devices were performed. Results: The obtained images demonstrate that phase based imaging methods can provide superior results compared to attenuation based modalities for weakly attenuating samples also in 3D. Moreover, and, most importantly, they demonstrate the feasibility of low-dose imaging. In addition, the experimental results can be considered quantitative within the constraints imposed by polychromaticity. Conclusions: The results, together with the method's dose efficiency and compatibility with conventional x-ray sources, indicate that tomographic EI XPCi can become an important tool for the routine imaging of biomedical samples.

  2. X-ray energy selected imaging with Medipix II

    International Nuclear Information System (INIS)

    Ludwig, J.; Zwerger, A.; Benz, K.-W.; Fiederle, M.; Braml, H.; Fauler, A.; Konrath, J.-P.

    2004-01-01

    Two different X-ray tube accelerating voltages (60 and 70 kV) are used for diagnosis of front teeth and molars. Different energy ranges are necessary as function of tooth thickness to obtain similar contrast for imaging. This technique drives the costs for the X-ray tube up and allows for just two optimized settings. Energy range selection for the detection of the penetrating X-rays would overcome these severe setbacks. The single photon counting chip MEDIPIX2 http://www.cern.ch/medipix exhibits exactly this feature. First simulations and measurements have been carried out using a dental X-ray source. As a demonstrator a real tooth has been used with different cavities and filling materials. Simulations showed in general larger improvements as compared to measurements regarding SNR and contrast: A beneficial factor of 4% wrt SNR and 25% for contrast, measurements showed factors of 2.5 and up to 10%, respectively

  3. X-ray energy selected imaging with Medipix II

    Science.gov (United States)

    Ludwig, J.; Zwerger, A.; Benz, K.-W.; Fiederle, M.; Braml, H.; Fauler, A.; Konrath, J.-P.

    2004-09-01

    Two different X-ray tube accelerating voltages (60 and 70kV) are used for diagnosis of front teeth and molars. Different energy ranges are necessary as function of tooth thickness to obtain similar contrast for imaging. This technique drives the costs for the X-ray tube up and allows for just two optimized settings. Energy range selection for the detection of the penetrating X-rays would overcome these severe setbacks. The single photon counting chip MEDIPIX2 http://www.cern.ch/medipix exhibits exactly this feature.First simulations and measurements have been carried out using a dental X-ray source. As a demonstrator a real tooth has been used with different cavities and filling materials. Simulations showed in general larger improvements as compared to measurements regarding SNR and contrast: A beneficial factor of 4% wrt SNR and 25% for contrast, measurements showed factors of 2.5 and up to 10%, respectively.

  4. X-ray images in the digital mode

    International Nuclear Information System (INIS)

    Buchmann, F.; Balter, S.

    1981-01-01

    In addition to computed tomography which presents actually the most important processing and transfer procedure of digital X-ray images, application of real time addition and substraction of X-ray images in a digital mode has found considerable interest. An estimation of the information contents of both digital and analog images is made in close relation to applications. As example of an image processing system on digital base a recently developed system for intravenous arteriography is described: the Philips-DVI. (orig.) [de

  5. X-ray generation by femtosecond laser pulses and its application to soft X-ray imaging microscope

    International Nuclear Information System (INIS)

    Ikeda, Kenichi; Kotaki, Hideyuki; Nakajima, Kazuhisa

    2002-01-01

    We have developed laser-produced plasma X-ray sources using femtosecond laser pulses at 10Hz repetition rate in a table-top size in order to investigate basic mechanism of X-ray emission from laser-matter interactions and its application to a X-ray microscope. In a soft X-ray region over 5 nm wavelength, laser-plasma X-ray emission from a solid target achieved an intense flux of photons of the order of 1011 photons/rad per pulse with duration of a few 100 ps, which is intense enough to make a clear imaging in a short time exposure. As an application of laser-produced plasma X-ray source, we have developed a soft X-ray imaging microscope operating in the wavelength range around 14 nm. The microscope consists of a cylindrically ellipsoidal condenser mirror and a Schwarzshird objective mirror with highly-reflective multilayers. We report preliminary results of performance tests of the soft X-ray imaging microscope with a compact laser-produced plasma X-ray source

  6. Radiation exposure and image quality in x-Ray diagnostic radiology physical principles and clinical applications

    CERN Document Server

    Aichinger, Horst; Joite-Barfuß, Sigrid; Säbel, Manfred

    2012-01-01

    The largest contribution to radiation exposure to the population as a whole arises from diagnostic X-rays. Protecting the patient from radiation is a major aim of modern health policy, and an understanding of the relationship between radiation dose and image quality is of pivotal importance in optimising medical diagnostic radiology. In this volume the data provided for exploring these concerns are partly based on X-ray spectra, measured on diagnostic X-ray tube assemblies, and are supplemented by the results of measurements on phantoms and simulation calculations.

  7. Two digital X-ray imaging systems for applications in X-ray diffraction

    International Nuclear Information System (INIS)

    Bateman, J.E.; Connolly, J.F.; Stephenson, R.; Flesher, A.C.; Tucker, P.A.; Swanton, S.W.

    1987-01-01

    Two digital X-ray imaging systems developed at the Rutherford Appleton Laboratory are described: the Mark I and the Mark II. Both use a bidimensionally sensitive multiwire proportional counter (MWPC) as the basic X-ray image transducer coupled, in the case of the Mark I to a Digital LSI 11-23 microcomputer system via CAMAC, and in the case of the Mark II to a Digital LSI 11-73 microcomputer system via custom-built data acquisition hardware mounted directly on the Q-bus of the microcomputer. The Mark I system provides the advantages of high speed, high sensitivity digital imaging directly into the computer with the potential for software control of the sample orientation and environment. The Mark II system adds the novel features of signal averaging and multiframe exposures. The dedicated digital memories have a resolution of 512x512 pixels of 16 bits, matching well to the spatial resolution of the xenon-filled MWPC (0.5 mm fwhm over an aperture of 200 mm x 200 mm). A 512x512x4 bit video graphics system displays the images in grey scales or colour. (orig.)

  8. Panel type X-ray image intensifier tube

    International Nuclear Information System (INIS)

    Wang, S.P.

    1977-01-01

    A panel shaped, proximity type, X-ray image intensifier tube for medical X-ray diagnostic is disclosed. It has all linear components and yet a high brightness gain, in the range of 500 to 20,000 cd-sec/m 2 -R, the tube being comprised of a rugged metallic tube envelope, an inwardly concave metallic input window of full size output display screen, an alkaline-halide scintillator photocathode screen suspended on insulators within the envelope and in between the input window and the output screen, and a high Z glass output window to reduce X-ray backscatter inside and outside of the tube. An X-ray sensitive photographic camera for medical diagnostic use is also disclosed which includes an X-ray sensitive image intensifier means of the proximity type and a reduction type optical system having an effective foral length in excess of 100mm for focusing the emage generated on the output display screen of the image intensifier tube onto a small size but directly viewable photographic film. The parameters of the image intensifier, the optics and the film are specified and linked to each other in a manner which maximizes the image quality for a camera system of this type and at the same time restricts the system speed of the camera to a range of 500 to 5,000 R -1 for the film to achieve a net density of 1.0. (Auth.)

  9. X-ray backscatter imaging with a spiral scanner

    International Nuclear Information System (INIS)

    Bossi, R.H.; Cline, J.L.; Friddell, K.D.

    1989-01-01

    X-ray backscatter imaging allows radiographic inspections to be performed with access to only one side of the object. A collimated beam of radiation striking an object will scatter x-rays by Compton scatter and x-ray fluorescence. A detector located on the source side of the part will measure the backscatter signal. By plotting signal strength as gray scale intensity vs. beam position on the object, an image of the object can be constructed. A novel approach to the motion of the collimated incident beam is a spiral scanner. The spiral scanner approach, described in this paper, can image an area of an object without the synchronized motion of the object or detector, required by other backscatter imaging techniques. X-ray backscatter is particularly useful for flaw detection in light element materials such as composites. The ease of operation and the ability to operate non-contact from one side of an object make x-ray backscatter imaging of increasing interest to industrial inspection problems

  10. Development of the water window imaging x-ray microscope

    International Nuclear Information System (INIS)

    Hoover, R.B.; Shealy, D.L.; Baker, P.C.; Barbee, T.W. Jr.; Walker, A.B.C. Jr.

    1991-01-01

    This paper reports on the Water Window Imaging X-ray Microscopy which is currently being developed by a consortium from the Marshall Space Flight Center, the University of Alabama at Birmingham, Baker Consulting, the Lawrence Livermore National Laboratory, and Stanford University. The high quality solar images achieved during the Stanford/MSFC/LLNL Rocket X-ray Spectroheliograph flight conclusively established that excellent imaging could be obtained with doubly reflecting multilayer optical systems. Theoretical studies carried out as part of the MSFC X-ray Microscopy Program, demonstrated that high quality, high resolution multilayer x-ray imaging microscopes could be achieved with spherical optics in the Schwarzschild configuration and with Aspherical optical systems. Advanced Flow Polishing methods have been used to fabricate substrates for multilayer optics. On hemlite grade Sapphire, the authors have achieved microscopy mirror substrates on concave and convex spherical surfaces with 0.5 Angstrom rms surface smoothness, as measured by the Zygo profilometer. In this paper the authors report on the current status of fabrication and testing of the optical and mechanical subsystems for the Water Window Imaging X-ray Microscope

  11. Image processing for x-ray inspection of pistachio nuts

    Science.gov (United States)

    Casasent, David P.

    2001-03-01

    A review is provided of image processing techniques that have been applied to the inspection of pistachio nuts using X-ray images. X-ray sensors provide non-destructive internal product detail not available from other sensors. The primary concern in this data is detecting the presence of worm infestations in nuts, since they have been linked to the presence of aflatoxin. We describe new techniques for segmentation, feature selection, selection of product categories (clusters), classifier design, etc. Specific novel results include: a new segmentation algorithm to produce images of isolated product items; preferable classifier operation (the classifier with the best probability of correct recognition Pc is not best); higher-order discrimination information is present in standard features (thus, high-order features appear useful); classifiers that use new cluster categories of samples achieve improved performance. Results are presented for X-ray images of pistachio nuts; however, all techniques have use in other product inspection applications.

  12. Ancient administrative handwritten documents: X-ray analysis and imaging

    International Nuclear Information System (INIS)

    Albertin, F.; Astolfo, A.; Stampanoni, M.; Peccenini, Eva; Hwu, Y.; Kaplan, F.; Margaritondo, G.

    2015-01-01

    The heavy-element content of ink in ancient administrative documents makes it possible to detect the characters with different synchrotron imaging techniques, based on attenuation or refraction. This is the first step in the direction of non-interactive virtual X-ray reading. Handwritten characters in administrative antique documents from three centuries have been detected using different synchrotron X-ray imaging techniques. Heavy elements in ancient inks, present even for everyday administrative manuscripts as shown by X-ray fluorescence spectra, produce attenuation contrast. In most cases the image quality is good enough for tomography reconstruction in view of future applications to virtual page-by-page ‘reading’. When attenuation is too low, differential phase contrast imaging can reveal the characters from refractive index effects. The results are potentially important for new information harvesting strategies, for example from the huge Archivio di Stato collection, objective of the Venice Time Machine project

  13. Ancient administrative handwritten documents: X-ray analysis and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Albertin, F., E-mail: fauzia.albertin@epfl.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Astolfo, A. [Paul Scherrer Institut (PSI), Villigen (Switzerland); Stampanoni, M. [Paul Scherrer Institut (PSI), Villigen (Switzerland); ETHZ, Zürich (Switzerland); Peccenini, Eva [University of Ferrara (Italy); Technopole of Ferrara (Italy); Hwu, Y. [Academia Sinica, Taipei, Taiwan (China); Kaplan, F. [Ecole Polytechnique Fédérale de Lausanne (EPFL) (Switzerland); Margaritondo, G. [Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2015-01-30

    The heavy-element content of ink in ancient administrative documents makes it possible to detect the characters with different synchrotron imaging techniques, based on attenuation or refraction. This is the first step in the direction of non-interactive virtual X-ray reading. Handwritten characters in administrative antique documents from three centuries have been detected using different synchrotron X-ray imaging techniques. Heavy elements in ancient inks, present even for everyday administrative manuscripts as shown by X-ray fluorescence spectra, produce attenuation contrast. In most cases the image quality is good enough for tomography reconstruction in view of future applications to virtual page-by-page ‘reading’. When attenuation is too low, differential phase contrast imaging can reveal the characters from refractive index effects. The results are potentially important for new information harvesting strategies, for example from the huge Archivio di Stato collection, objective of the Venice Time Machine project.

  14. Novel X-ray imaging diagnostics of high energy nanosecond pulse accelerators

    International Nuclear Information System (INIS)

    Smith, Graham W.; Gallegos, Roque Rosauro; Hohlfelder, Robert James; Beutler, David Eric; Dudley, John; Seymour, Calvin L.G.; Bell, John D.

    2004-01-01

    Pioneering x-ray imaging has been undertaken on a number of AWE's and Sandia National Laboratories radiation effects x-ray simulators. These simulators typically yield a single very short (<50ns) pulse of high-energy (MeV endpoint energy bremsstrahlung) x-ray radiation with doses in the kilorad (krad(Si)) region. X-ray source targets vary in size from 2 to 25cm diameter, dependent upon the particular simulator. Electronic imaging of the source x-ray emission under dynamic conditions yields valuable information upon how the simulator is performing. The resultant images are of interest to the simulator designer who may configure new x-ray source converter targets and diode designs. The images can provide quantitative information about machine performance during radiation effects testing of components under active conditions. The effects testing program is a valuable interface for validation of high performance computer codes and models for the radiation effects community. A novel high-energy x-ray imaging spectrometer is described whereby the spectral energy (0.1 to 2.5MeV) profile may be discerned from the digitally recorded and viewable images via a pinhole/scintillator/CCD imaging system and knowledge of the filtration parameters. Unique images, analysis and a preliminary evaluation of the capability of the spectrometer are presented. Further, a novel time resolved imaging system is described that captures a sequence of high spatial resolution temporal images, with zero interframe time, in the nanosecond timeframe, of our source x-rays.

  15. Transforming Our Understanding of the X-ray Universe: The Imaging X-ray Polarimeter Explorer (IXPE)

    Science.gov (United States)

    Weisskopf, Martin C.; Bellazzini, Ronaldo; Costa, Enrico; Matt, Giorgio; Marshall, Herman; ODell, Stephen L.; Pavlov, George; Ramsey, Brian; Romani, Roger

    2014-01-01

    Accurate X-ray polarimetry can provide unique information on high-energy-astrophysical processes and sources. As there have been no meaningful X-ray polarization measurements of cosmic sources since our pioneering work in the 1970's, the time is ripe to explore this new parameter space in X-ray astronomy. To accomplish this requires a well-calibrated and well understood system that-particularly for an Explorer mission-has technical, cost, and schedule credibility. The system that we shall present satisfies these conditions, being based upon completely calibrated imaging- and polarization-sensitive detectors and proven X-ray-telescope technology.

  16. X-ray imaging with monochromatic synchrotron radiation. Fluorescent and phase-contrast method

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Tohoru; Itai, Yuji [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine

    2002-05-01

    To obtain the high sensitive x-ray images of biomedical object, new x-ray imaging techniques using fluorescent x-ray and phase-contrast x-ray are being developed in Japan. Fluorescent x-ray CT can detect very small amounts of specific elements in the order of ppm at one pixel, whereas phase-contrast x-ray imaging with interferometer can detect minute differences of biological object. Here, our recent experimental results are presented. (author)

  17. Submicron hard X-ray fluorescence imaging of synthetic elements.

    Science.gov (United States)

    Jensen, Mark P; Aryal, Baikuntha P; Gorman-Lewis, Drew; Paunesku, Tatjana; Lai, Barry; Vogt, Stefan; Woloschak, Gayle E

    2012-04-13

    Synchrotron-based X-ray fluorescence microscopy (XFM) using hard X-rays focused into sub-micron spots is a powerful technique for elemental quantification and mapping, as well as microspectroscopic measurements such as μ-XANES (X-ray absorption near edge structure). We have used XFM to image and simultaneously quantify the transuranic element plutonium at the L(3) or L(2)-edge as well as Th and lighter biologically essential elements in individual rat pheochromocytoma (PC12) cells after exposure to the long-lived plutonium isotope (242)Pu. Elemental maps demonstrate that plutonium localizes principally in the cytoplasm of the cells and avoids the cell nucleus, which is marked by the highest concentrations of phosphorus and zinc, under the conditions of our experiments. The minimum detection limit under typical acquisition conditions with an incident X-ray energy of 18 keV for an average 202 μm(2) cell is 1.4 fg Pu or 2.9×10(-20) moles Pu μm(-2), which is similar to the detection limit of K-edge XFM of transition metals at 10 keV. Copper electron microscopy grids were used to avoid interference from gold X-ray emissions, but traces of strontium present in naturally occurring calcium can still interfere with plutonium detection using its L(α) X-ray emission. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Femtosecond X-ray Fourier holography imaging of freeflying nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Gorkhover, Tais; Ulmer, Anatoli; Ferguson, Ken R.; Bucher, Max; Maia, Filipe R.N.C.; Bielecki, Johan; Ekeberg, Tomas; Hantke, Max F.; Daurer, Benedikt J.; Bostedt, Christoph

    2018-02-26

    Ultrafast X-ray imaging on individual fragile specimens such as aerosols1, metastable particles2, superfluid quantum systems3 and live biospecimen4 provides high resolution information, which is inaccessible with conventional imaging techniques. Coherent X-ray diffractive imag- 2 ing, however, suffers from intrinsic loss of phase, and therefore structure recovery is often complicated and not always uniquely-defined4, 5. Here, we introduce the method of in-flight holography, where we use nanoclusters as reference X-ray scatterers in order to encode relative phase information into diffraction patterns of a virus. The resulting hologram contains an unambiguous three-dimensional map of a virus and two nanoclusters with the highest lateral resolution so far achieved via single shot X-ray holography. Our approach unlocks the benefits of holography for ultrafast X-ray imaging of nanoscale, non-periodic systems and paves the way to direct observation of complex electron dynamics down to the attosecond time scale.

  19. The x-ray time of flight method for investigation of ghosting in amorphous selenium-based flat panel medical x-ray imagers

    International Nuclear Information System (INIS)

    Rau, A.W.; Bakueva, L.; Rowlands, J.A.

    2005-01-01

    Amorphous selenium (a-Se) based real-time flat-panel imagers (FPIs) are finding their way into the digital radiology department because they offer the practical advantages of digital x-ray imaging combined with an image quality that equals or outperforms that of conventional systems. The temporal imaging characteristics of FPIs can be affected by ghosting (i.e., radiation-induced changes of sensitivity) when the dose to the detector is high (e.g., portal imaging and mammography) or the images are acquired at a high frame rate (e.g., fluoroscopy). In this paper, the x-ray time-of-flight (TOF) method is introduced as a tool for the investigation of ghosting in a-Se photoconductor layers. The method consists of irradiating layers of a-Se with short x-ray pulses. From the current generated in the a-Se layer, ghosting is quantified and the ghosting parameters (charge carrier generation rate and carrier lifetimes and mobilities) are assessed. The x-ray TOF method is novel in that (1) x-ray sensitivity (S) and ghosting parameters can be measured simultaneously (2) the transport of both holes and electrons can be isolated, and (3) the method is applicable to the practical a-Se layer structure with blocking contacts used in FPIs. The x-ray TOF method was applied to an analysis of ghosting in a-Se photoconductor layers under portal imaging conditions, i.e., 1 mm thick a-Se layers, biased at 5 V/μm, were irradiated using a 6 MV LINAC x-ray beam to a total dose (ghosting dose) of 30 Gy. The initial sensitivity (S 0 ) of the a-Se layers was 63±2 nC cm -2 cGy -1 . It was found that S decreases to 30% of S 0 after a ghosting dose of 5 Gy and to 21% after 30 Gy at which point no further change in S occurs. At an x-ray intensity of 22 Gy/s (instantaneous dose rate during a LINAC x-ray pulse), the charge carrier generation rate was 1.25±0.1x10 22 ehp m -3 s -1 and, to a first approximation, independent of the ghosting dose. However, both hole and electron transport showed a

  20. Analyser-based x-ray imaging for biomedical research

    International Nuclear Information System (INIS)

    Suortti, Pekka; Keyriläinen, Jani; Thomlinson, William

    2013-01-01

    Analyser-based imaging (ABI) is one of the several phase-contrast x-ray imaging techniques being pursued at synchrotron radiation facilities. With advancements in compact source technology, there is a possibility that ABI will become a clinical imaging modality. This paper presents the history of ABI as it has developed from its laboratory source to synchrotron imaging. The fundamental physics of phase-contrast imaging is presented both in a general sense and specifically for ABI. The technology is dependent on the use of perfect crystal monochromator optics. The theory of the x-ray optics is developed and presented in a way that will allow optimization of the imaging for specific biomedical systems. The advancement of analytical algorithms to produce separate images of the sample absorption, refraction angle map and small-angle x-ray scattering is detailed. Several detailed applications to biomedical imaging are presented to illustrate the broad range of systems and body sites studied preclinically to date: breast, cartilage and bone, soft tissue and organs. Ultimately, the application of ABI in clinical imaging will depend partly on the availability of compact sources with sufficient x-ray intensity comparable with that of the current synchrotron environment. (paper)

  1. Direct comparison of soft x-ray images of organelles with optical fluorescence images

    International Nuclear Information System (INIS)

    Ishino, Masahiko; Kado, Masataka; Kishimoto, Maki; Nishikino, Masaharu; Ohba, Toshiyuki; Kaihori, Takeshi; Kawachi, Tetsuya; Tamotsu, Satoshi; Yasuda, Keiko; Mikata, Yuji; Shinohara, Kunio

    2011-01-01

    Soft x-ray microscopes operating in the water window region are capable of imaging living hydrated cells. Up to now, we have been able to take some soft x-ray images of living cells by the use of a contact x-ray microscope system with laser produced plasma soft x-ray source. Since the soft x-ray images are different from the optical images obtained with an ordinary microscope, it is very important to identify what is seen in the x-ray images. Hence, we have demonstrated the direct comparison between the images of organelles obtained with a fluorescence microscope and those with a soft x-ray microscope. Comparing the soft x-ray images to the fluorescence images, the fine structures of the organelles could be identified and observed. (author)

  2. Recent developments in detectors/phantoms for dosimetry, X-ray quality assurance and imaging

    International Nuclear Information System (INIS)

    Sankaran, A.

    2009-01-01

    During the past years, many new developments have taken place in detectors/phantoms for high energy photon and electron dosimetry (for radiotherapy), protection monitoring, X-ray quality assurance and X-ray imaging (for radiodiagnosis). A variety of detectors and systems, quality assurance (QA) gadgets and special phantoms have been developed for diverse applications. This paper discusses the important developments with some of which the author was actively associated in the past. For dosimetry and QA of 60 Co and high energy X-ray units, state-of-the-art radiation field analyzers, matrix ion chambers, MOSFET devices and Gafchromic films are described. OSL detectors find wide use in radiotherapy dosimetry and provide a good alternative for personnel monitoring. New systems introduced for QA/dosimetry of X-ray units and CT scanners include: multi-function instruments for simultaneous measurement of kVp, dose, time, X-ray waveform and HVT on diagnostic X-ray units; pencil chamber with head and body phantoms for CTDI check on CT scanners. Examples of phantoms used for dosimetry and imaging are given. Advancements in the field of diagnostic X-ray imaging (with applications in portal imaging/dosimetry of megavoltage X-ray units) have led to emergence of: film-replacement systems employing CCD-scintillator arrays, computed radiography (CR) using storage phosphor plate; digital radiography (DR), using a pixel-matrix of amorphous selenium, or amorphous silicon diode coupled to scintillator. All these provide (a) in radiotherapy, accurate dose delivery to tumour, saving the surrounding tissues and (b) in radiodiagnosis, superior image quality with low patient exposure. Lastly, iPODs and flash drives are utilized for storage of gigabyte-size images encountered in medical and allied fields. Although oriented towards medical applications, some of these have been of great utility in other fields, such as industrial radiography as well as a host of other research areas. (author)

  3. X-ray images in primary bone chondrosarcoma

    International Nuclear Information System (INIS)

    Syrtmadzhieva, S.; Andreev, I.; Velichkov, L.

    1982-01-01

    The X-ray images of primary bone chondrosarcomas in 76 patients are reviewed. The tumors have been localized largely in the long tubular bones - in some patients centrally or excentrically, in others superficially. The X-ray images presented with osteolytic, osteoplastic and mixed changes, intratumor calcifications and reactive bone and periosteal changes. The presence of any of these changes and their combinations, depending on the localization and the influence of a variety of other factors, resembled much many other primary and metastatic malignant bone tumors, benign bone tumors and tumor-like diseases. The X-ray images showed a major complexity in the development of the primary chondrosarcoma and its relations with the bone as organ. (author)

  4. Noise reduction in real time x-ray images

    International Nuclear Information System (INIS)

    Tsuda, Motohisa; Kimura, Yutaro

    1986-01-01

    The signal-to-noise ratio of real-time digital X-ray imaging systems consisting of an X-ray image intensifer-television chain was investigated while concentrating on the effect of the X-ray quantum nature. Along with conventional signal accumulation, logarithmic conversion and subtraction, a new technique called the peak hold method is introduced. Theoretical and simulational studies were made with practical parameters. Theory and simulation showed good agreement. An accumulation of signal is most effective for improving the signal-to-noise ratio; the peak-hold method comes next. The peak hold method, however, offers a new image-display mode. Moreover, this method is superior to signal accumulation for specific conditions. (author)

  5. The study on clinical conditions and skin dose of upper-gastrointestinal x-ray fluoroscopy

    International Nuclear Information System (INIS)

    Kim, Sung Chul; Ahn, Sung Min; Jang, Sang Sup

    2007-01-01

    This study examined present conditions of upper-gastrointestinal X-ray fluoroscopy and patient skin dose. The authors elected 21 equipment to check the X-ray equipment and exposure factor of fluoroscopy and spot exposure in university hospitals, hospitals, and clinics where perform upper-gastrointestinal X-ray fluoroscopy more than five times every day in Incheon areas. The amount of patient's skin dose during upper-gastrointestinal X-ray fluoroscopy was measured by ionization chamber

  6. X-ray scatter signatures for enhanced breast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kidane, Ghirmay; Speller, Robert; Royle, Gary [Medical Physics and Bioengineering Department, University College Landon, 11-20 Capper Street, London WC1E 6JA (United Kingdom)

    1999-12-31

    Conventional mammographic imaging suffers from a low specificity. The main cause is the small difference in the x-ray attenuation properties of healthy and diseased tissue leading to poor contrast in the image. It has been observed that additional information on breast tissue type can be obtained from x-ray diffraction effects. A study of excised normal and neoplastic breast tissue samples using x-ray diffraction apparatus has been observed that significant differences exist in the measured spectra between carcinoma and healthy tissue adjacent to the carcinoma. Such a difference allows tissue type to be characterised according to is diseased state. Furthermore the information can be applied to improve diagnosis. It is proposed that collection and analysis of the scattered x-rays present during a mammographic procedure can supply the additional information and be used to improve the image contrast. The ultimate aim of the project is to improve the specificity of x-ray mammography. (authors) 10 refs., 3 figs.

  7. Synchrotron X-ray imaging applied to solar photovoltaic silicon

    International Nuclear Information System (INIS)

    Lafford, T A; Villanova, J; Plassat, N; Dubois, S; Camel, D

    2013-01-01

    Photovoltaic (PV) cell performance is dictated by the material of the cell, its quality and purity, the type, quantity, size and distribution of defects, as well as surface treatments, deposited layers and contacts. A synchrotron offers unique opportunities for a variety of complementary X-ray techniques, given the brilliance, spectrum, energy tunability and potential for (sub-) micron-sized beams. Material properties are revealed within in the bulk and at surfaces and interfaces. X-ray Diffraction Imaging (X-ray Topography), Rocking Curve Imaging and Section Topography reveal defects such as dislocations, inclusions, misorientations and strain in the bulk and at surfaces. Simultaneous measurement of micro-X-Ray Fluorescence (μ-XRF) and micro-X-ray Beam Induced Current (μ-XBIC) gives direct correlation between impurities and PV performance. Together with techniques such as microscopy and Light Beam Induced Current (LBIC) measurements, the correlation between structural properties and photovoltaic performance can be deduced, as well as the relative influence of parameters such as defect type, size, spatial distribution and density (e.g [1]). Measurements may be applied at different stages of solar cell processing in order to follow the evolution of the material and its properties through the manufacturing process. Various grades of silicon are under study, including electronic and metallurgical grades in mono-crystalline, multi-crystalline and mono-like forms. This paper aims to introduce synchrotron imaging to non-specialists, giving example results on selected solar photovoltaic silicon samples.

  8. X-ray imaging in the laser-fusion program

    International Nuclear Information System (INIS)

    McCall, G.H.

    1977-01-01

    Imaging devices which are used or planned for x-ray imaging in the laser-fusion program are discussed. Resolution criteria are explained, and a suggestion is made for using the modulation transfer function as a uniform definition of resolution for these devices

  9. Quality control and patient dose from X-ray examinations in some hospitals in Estonia

    International Nuclear Information System (INIS)

    Servomaa, A.; Rannikko, S.; Parviainen, T.; Holmberg, P.; Kuus, E.; Mueuersepps, T.; Jaerv, V.

    1995-01-01

    Quality control measurements of X ray diagnostic units were carried out in four hospitals in Estonia. Measurements were focused on the unit's technical performance, on image quality and on patient dose and film processing. The main problems are in the areas of image receptors and film processing: image receptors are of low speed type causing high patient doses and manual film processing results in low contrast and high base plus fog. Spatial resolution, both in film imaging and in image intensifiers, is reasonably good. It is recommended that quality assurance programmes be established, that basic measuring equipment be acquired and personnel assigned to perform such measurements be trained. (Author)

  10. Nanoscale X-Ray Microscopic Imaging of Mammalian Mineralized Tissue

    OpenAIRE

    Andrews, Joy C.; Almeida, Eduardo; van der Meulen, Marjolein C.H.; Alwood, Joshua S.; Lee, Chialing; Liu, Yijin; Chen, Jie; Meirer, Florian; Feser, Michael; Gelb, Jeff; Rudati, Juana; Tkachuk, Andrei; Yun, Wenbing; Pianetta, Piero

    2010-01-01

    A novel hard transmission X-ray microscope (TXM) at the Stanford Synchrotron Radiation Light-source operating from 5 to 15 keV X-ray energy with 14 to 30 µm2 field of view has been used for high-resolution (30–40 nm) imaging and density quantification of mineralized tissue. TXM is uniquely suited for imaging of internal cellular structures and networks in mammalian mineralized tissues using relatively thick (50 µm), untreated samples that preserve tissue micro- and nanostructure. To test this...

  11. Magnetic imaging by dichroic x-ray holography

    International Nuclear Information System (INIS)

    Eisebitt, S.; Loergen, M.; Eberhardt, W.; Luening, M.; Schlotter, W.F.; Stoehr, J.; Hellwig, O.

    2004-01-01

    Full text: While holography has evolved to a powerful technique in the visible spectral range, it is difficult to apply at shorter wavelength as no intrinsically coherent (soft) x-ray laser is available as a light source. The progression from visible light towards shorter wavelength is motivated by the increase in spatial resolution that can be achieved. Of equal importance is the possibility to exploit special contrast mechanisms provided by scattering in resonance with transitions between electronic core and valence levels. These contrast mechanisms can be utilized in x-ray holography to form a spectroscopic image of the sample, in analogy to spectromicroscopy. So far, successful x-ray spectroholography has not been reported due to the experimental difficulties associated with the short wavelength and the limited coherent photon flux available. We present images of magnetic domain patterns forming in thin film Co-Pt multilayers, obtained by spectroholography at a wavelength of 1.59 nm. At this wavelength, we exploit x ray magnetic dichroism at the Co 2p 3/2 level in a Fourier transform holography experiment. Holography at this wavelength was made possible by combining nanostructured masks with coherence l tered synchrotron radiation from an undulator source in the experimental setup. The magnetic multilayers have perpendicular anisotropy and are probed using circular polarized x-rays. Dichroic holograms are recorded by combining measurements with positive and negative helicities. The spectroholograms can be numerically inverted to show the pure magnetic sample structure, such as labyrinth or stripe domains. Currently, we achieve a spatial resolution of 100 nm in the magnetic image. The advantages and limitations of this technique will be compared to other lensless imaging techniques such as over sampling phasing. The future prospects of imaging techniques based on coherent scattering are discussed in the context of the current development of free electron x-ray

  12. Radiation doses to patients from x-ray examinations - development from 2005 to 2008

    International Nuclear Information System (INIS)

    Leitz, Wolfram; Almen, Anja

    2010-04-01

    Data has been compiled and analyzed and compared with the earlier reports. Radiation doses were tested for possible links with various parameters (eg type of x-ray equipment, image recording systems, different technique factors). In conventional x-ray examinations radiation doses were, for equipment with direct digital image receivers, in average 30% lower than for those with photo plates. Mammography doses were, with one exception, the same for all types of equipment and video receivers. The CT-examinations had a small trend for higher doses for new equipment as compared to earlier. Use of exposure automation did not affect radiation doses. Compared with 2006, the doses of conventional surveys decreased by an average of 21%. One third of this dose reduction can be attributed the introduction of direct digital system whose use grew by about 30%. Most of the dose reduction can be attributed to the actions carried out to lower the dose of the reference level. Doses for the CT scan showed only a weak downwards trend. Mammography Doses decreased by an average of just over 10% a large part dependent on increased number of Sectra equipment. The system of diagnostic reference levels have again shown to have positive influence on the radiation level at the x-ray examinations, this is most pronounced for conventional radiography. There is still a large potential for dose reduction, and a measure to achieve this is to reduce the current reference levels. Very few diagnostic Standard doses are higher than the reference level. A reduction of the reference levels corresponding to the third quartile of dose distribution could lead further dose decrease of 10-20%. The corresponding reduction in dose should be done also for the DT and mammograms when lowering the reference level, there are few standard doses higher than the current reference levels

  13. The Imaging X-Ray Polarimetry Explorer (IXPE)

    Science.gov (United States)

    Weisskopf, Martin C.; Ramsey, Brian; O’Dell, Stephen; Tennant, Allyn; Elsner, Ronald; Soffita, Paolo; Bellazzini, Ronaldo; Costa, Enrico; Kolodziejczak, Jeffery; Kaspi, Victoria; hide

    2016-01-01

    The Imaging X-ray Polarimetry Explorer (IXPE) is an exciting international collaboration for a scientific mission that dramatically brings together the unique talents of the partners to expand observation space by simultaneously adding polarization measurements to the array of source properties currently measured (energy, time, and location). IXPE uniquely brings to the table polarimetric imaging. IXPE will thus open new dimensions for understanding how X-ray emission is produced in astrophysical objects, especially systems under extreme physical conditions-such as neutron stars and black holes. Polarization singularly probes physical anisotropies-ordered magnetic fields, aspheric matter distributions, or general relativistic coupling to black-hole spin-that are not otherwise measurable. Hence, IXPE complements all other investigations in high-energy astrophysics by adding important and relatively unexplored information to the parameter space for studying cosmic X-ray sources and processes, as well as for using extreme astrophysical environments as laboratories for fundamental physics.

  14. Dilation x-ray imager a new/faster gated x-ray imager for the NIF [DIXI (Dilation x-ray imager) a new/faster gated x-ray imager for the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, S. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hilsabeck, T. J.; Bell, P. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bradley, D. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ayers, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Barrios, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Felker, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Smith, R. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Collins, G. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jones, O. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kilkenny, J. D. [General Atomics, San Diego, CA (United States); Chung, T. [General Atomics, San Diego, CA (United States); Piston, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Raman, K. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sammuli, B. [General Atomics, San Diego, CA (United States); Hares, J. D. [Kentech Instruments Ltd., Wallingford, Oxfordshire (United Kingdom); Dymoke-Bradshaw, A. K. L. [Kentech Instruments Ltd., Wallingford, Oxfordshire (United Kingdom)

    2012-07-19

    As the yield on implosion shots increases it is expected that the peak x-ray emission reduces to a duration with a FWHM as short as 20 ps for ~7 1018 neutron yield. However, the temporal resolution of currently used gated x-ray imagers on the NIF is 40-100 ps. We discuss the benefits of the higher temporal resolution for the NIF and present performance measurements for DIXI, which utilizes pulse-dilation technology [1] to achieve x-ray imaging with temporal gate times below 10 ps. Lastly, the measurements were conducted using the COMET laser, which is part of the Jupiter Laser Facility at the Lawrence Livermore National Laboratory.

  15. Absorbed and effective dose from periapical radiography by portable intraoral x-ray machine

    International Nuclear Information System (INIS)

    Cho, Jeong Yeon; Han, Won Jeong; Kim, Eun Kyung

    2007-01-01

    The purpose of this study was to measure the absorbed dose and to calculate the effective dose for periapical radiography done by portable intraoral x-ray machines. 14 full mouth, upper posterior and lower posterior periapical radiographs were taken by wall-type 1 and portable type 3 intraoral x-ray machines. Thermoluminescent dosemeters were placed at 23 sites at the layers of the tissue-equivalent ART woman phantom for dosimetry. Average tissue absorbed dose and radiation weighted dose were calculated for each major anatomical site. Effective dose was calculated using 2005 ICRP tissue weighted factors. On 14 full mouth periapical radiographs, the effective dose for wall-type x-ray machine was 30 Sv; for portable x-ray machines were 30 Sv, 22 Sv, 36 Sv. On upper posterior radiograph, the effective dose for wall-type x-ray machine was 4 Sv; for portable x-ray machines doses were 4 Sv, 3 Sv, 5 Sv. On lower posterior radiograph, the effective dose for wall type x-ray machine was 5 Sv; for portable x-ray machines doses were 4 Sv, 4 Sv, 5 Sv. Effective doses for periapical radiographs performed by portable intraoral x-ray machines were similar to doses for periapical radiographs taken by wall type intraoral x-ray machines

  16. Adult and child doses in standardised X ray examinations

    International Nuclear Information System (INIS)

    Gallini, R.E.; Belletti, S.; Berna, V.; Giugni, U.

    1992-01-01

    Data are presented on patient doses measured during standard hospital routine in seven radiological departments in the Province of Brescia. This study is part of a Quality Assurance Programme, carried out to assess the possibility and validity of a regional protocol. Before collecting dose data, tests on the performance of the X ray units and processors were performed in every department according to a Quality Control Protocol. The following examinations were considered: chest, knee, lumbar spine, pelvis, skull and barium meal. The surface entrance doses of 314 adults and 216 children were measured. The sample size for barium meal was lower: 65 adults and only 10 children. The patients anthropometric data and the technical parameters used were collected at the same time. For adults the organ doses and effective dose equivalent (EDE) were calculated. A wide range of entrance doses were obtained both for adults and children. The reasons can be: patient size, performance of the equipment and processors, film-screen combination, use of AEC, use of fluoroscopy and grid, training and skill of the staff

  17. Adult and child doses in standardised X ray examinations

    International Nuclear Information System (INIS)

    Gallini, R.E.; Belletti, S.; Berna, V.; Giugni, U.

    1992-01-01

    Data are presented on patient doses measured during standard hospital routine in seven radiological departments in the Province of Brescia, as part of a Quality Assurance Programme, carried out to assess the possibility and validity of a regional protocol. Before collecting dose data, tests on the performance of the X ray units and processors were performed in every department according to a Quality Control Protocol. The following examinations were considered: chest, knee, lumbar spine, pelvis, skull and barium meal. Surface entrance doses of 314 adults and 216 children were measured. The sample size for barium meal was lower: 65 adults and 10 children. The patients anthropometric data and technical parameters used were collected at the same time. For adults the organ doses and effective dose equivalent (EDE) were calculated. A wide range of entrance doses were obtained both for adults and children, due to patient size, performance of the equipment and processors, film-screen combination, use of AEC, use of fluoroscopy and grid, training and skill of the staff. (author)

  18. Optimization of X-ray phase-contrast imaging based on in-line holography

    International Nuclear Information System (INIS)

    Wu Xizeng; Liu Hong; Yan Aimin

    2005-01-01

    This paper introduces a newly conceived formalism for clinical in-line phase-contrast X-ray imaging. The new formalism applies not only to ideal 'thin' objects analyzed in previous studies, but also applies to the real-world tissues used in actual clinical practice. Moreover we have identified the four clinically important factors that affect phase-contrast characteristics. These factors are: (1) body part attenuation (2) the spatial coherence of incident X-rays from an X-ray tube (3) the polychromatic nature of the X-ray source and (4) radiation dose to patients for clinical applications. Techniques of phase image-reconstruction based on the new X-ray in-line holography theory are discussed. Numerical simulations are described which were used to validate the theory. The design parameters of an optimal clinical phase-contrast mammographic imaging system which were determined based on the new theory, and validated in the simulations, are presented. The theory, image reconstruction algorithms, and numerical simulation techniques presented in this paper can be applied widely to clinical diagnostic X-ray imaging applications

  19. Biological imaging by soft X-ray diffraction microscopy

    Science.gov (United States)

    Shapiro, David

    We have developed a microscope for soft x-ray diffraction imaging of dry or frozen hydrated biological specimens. This lensless imaging system does not suffer from the resolution or specimen thickness limitations that other short wavelength microscopes experience. The microscope, currently situated at beamline 9.0.1 of the Advanced Light Source, can collect diffraction data to 12 nm resolution with 750 eV photons and 17 nm resolution with 520 eV photons. The specimen can be rotated with a precision goniometer through an angle of 160 degrees allowing for the collection of nearly complete three-dimensional diffraction data. The microscope is fully computer controlled through a graphical user interface and a scripting language automates the collection of both two-dimensional and three-dimensional data. Diffraction data from a freeze-dried dwarf yeast cell, Saccharomyces cerevisiae carrying the CLN3-1 mutation, was collected to 12 run resolution from 8 specimen orientations spanning a total rotation of 8 degrees. The diffraction data was phased using the difference map algorithm and the reconstructions provide real space images of the cell to 30 nm resolution from each of the orientations. The agreement of the different reconstructions provides confidence in the recovered, and previously unknown, structure and indicates the three dimensionality of the cell. This work represents the first imaging of the natural complex refractive contrast from a whole unstained cell by the diffraction microscopy method and has achieved a resolution superior to lens based x-ray tomographic reconstructions of similar specimens. Studies of the effects of exposure to large radiation doses were also carried out. It was determined that the freeze-dried cell suffers from an initial collapse, which is followed by a uniform, but slow, shrinkage. This structural damage to the cell is not accompanied by a diminished ability to see small features in the specimen. Preliminary measurements on frozen

  20. X-ray phase contrast imaging at MAMI

    International Nuclear Information System (INIS)

    El-Ghazaly, M.; Backe, H.; Lauth, W.; Kube, G.; Kunz, P.; Sharafutdinov, A.; Weber, T.

    2006-01-01

    Experiments have been performed to explore the potential of the low emittance 855 MeV electron beam of the Mainz Microtron MAMI for imaging with coherent X-rays. Transition radiation from a micro-focused electron beam traversing a foil stack served as X-ray source with good transverse coherence. Refraction contrast radiographs of low absorbing materials, in particular polymer strings with diameters between 30 and 450 μm, were taken with a polychromatic transition radiation X-ray source with a spectral distribution in the energy range between 8 and about 40 keV. The electron beam spot size had standard deviation σ h =(8.6±0.1) μm in the horizontal and σ v =(7.5±0.1) μm in the vertical direction. X-ray films were used as detectors. The source-to-detector distance amounted to 11.4 m. The objects were placed in a distance of up to 6m from the X-ray film. Holograms of strings were taken with a beam spot size σ v =(0.50±0.05) μm in vertical direction, and a monochromatic X-ray beam of 6keV energy. A good longitudinal coherence has been obtained by the (111) reflection of a flat silicon single crystal in Bragg geometry. It has been demonstrated that a direct exposure CCD chip with a pixel size of 13 x 13 μm 2 provides a highly efficient on-line detector. Contrast images can easily be generated with a complete elimination of all parasitic background. The on-line capability allows a minimization of the beam spot size by observing the smallest visible interference fringe spacings or the number of visible fringes. It has been demonstrated that X-ray films are also very useful detectors. The main advantage in comparison with the direct exposure CCD chip is the resolution. For the Structurix D3 (Agfa) X-ray film the standard deviation of the resolution was measured to be σ f =(1.2±0.4) μm, which is about a factor of 6 better than for the direct exposure CCD chip. With the small effective X-ray spot size in vertical direction of σ v =(1.2±0.3)μm and a

  1. X-ray phase contrast imaging at MAMI

    Energy Technology Data Exchange (ETDEWEB)

    El-Ghazaly, M.; Backe, H.; Lauth, W.; Kube, G.; Kunz, P.; Sharafutdinov, A.; Weber, T. [Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany)

    2006-05-15

    Experiments have been performed to explore the potential of the low emittance 855 MeV electron beam of the Mainz Microtron MAMI for imaging with coherent X-rays. Transition radiation from a micro-focused electron beam traversing a foil stack served as X-ray source with good transverse coherence. Refraction contrast radiographs of low absorbing materials, in particular polymer strings with diameters between 30 and 450 {mu}m, were taken with a polychromatic transition radiation X-ray source with a spectral distribution in the energy range between 8 and about 40 keV. The electron beam spot size had standard deviation {sigma}{sub h}=(8.6{+-}0.1) {mu}m in the horizontal and {sigma}{sub v}=(7.5{+-}0.1) {mu}m in the vertical direction. X-ray films were used as detectors. The source-to-detector distance amounted to 11.4 m. The objects were placed in a distance of up to 6m from the X-ray film. Holograms of strings were taken with a beam spot size {sigma}{sub v}=(0.50{+-}0.05) {mu}m in vertical direction, and a monochromatic X-ray beam of 6keV energy. A good longitudinal coherence has been obtained by the (111) reflection of a flat silicon single crystal in Bragg geometry. It has been demonstrated that a direct exposure CCD chip with a pixel size of 13 x 13 {mu}m{sup 2} provides a highly efficient on-line detector. Contrast images can easily be generated with a complete elimination of all parasitic background. The on-line capability allows a minimization of the beam spot size by observing the smallest visible interference fringe spacings or the number of visible fringes. It has been demonstrated that X-ray films are also very useful detectors. The main advantage in comparison with the direct exposure CCD chip is the resolution. For the Structurix D3 (Agfa) X-ray film the standard deviation of the resolution was measured to be {sigma}{sub f}=(1.2{+-}0.4) {mu}m, which is about a factor of 6 better than for the direct exposure CCD chip. With the small effective X-ray spot size

  2. X-ray phase contrast imaging at MAMI

    Science.gov (United States)

    El-Ghazaly, M.; Backe, H.; Lauth, W.; Kube, G.; Kunz, P.; Sharafutdinov, A.; Weber, T.

    2006-05-01

    Experiments have been performed to explore the potential of the low emittance 855MeV electron beam of the Mainz Microtron MAMI for imaging with coherent X-rays. Transition radiation from a micro-focused electron beam traversing a foil stack served as X-ray source with good transverse coherence. Refraction contrast radiographs of low absorbing materials, in particular polymer strings with diameters between 30 and 450μm, were taken with a polychromatic transition radiation X-ray source with a spectral distribution in the energy range between 8 and about 40keV. The electron beam spot size had standard deviation σh = (8.6±0.1)μm in the horizontal and σv = (7.5±0.1)μm in the vertical direction. X-ray films were used as detectors. The source-to-detector distance amounted to 11.4m. The objects were placed in a distance of up to 6m from the X-ray film. Holograms of strings were taken with a beam spot size σv = (0.50±0.05)μm in vertical direction, and a monochromatic X-ray beam of 6keV energy. A good longitudinal coherence has been obtained by the (111) reflection of a flat silicon single crystal in Bragg geometry. It has been demonstrated that a direct exposure CCD chip with a pixel size of 13×13μm^2 provides a highly efficient on-line detector. Contrast images can easily be generated with a complete elimination of all parasitic background. The on-line capability allows a minimization of the beam spot size by observing the smallest visible interference fringe spacings or the number of visible fringes. It has been demonstrated that X-ray films are also very useful detectors. The main advantage in comparison with the direct exposure CCD chip is the resolution. For the Structurix D3 (Agfa) X-ray film the standard deviation of the resolution was measured to be σf = (1.2±0.4)μm, which is about a factor of 6 better than for the direct exposure CCD chip. With the small effective X-ray spot size in vertical direction of σv = (1.2±0.3)μm and a geometrical

  3. Phase contrast imaging with coherent high energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Snigireva, I. [ESRF, Grenoble (France)

    1997-02-01

    X-ray imaging concern high energy domain (>6 keV) like a contact radiography, projection microscopy and tomography is used for many years to discern the features of the internal structure non destructively in material science, medicine and biology. In so doing the main contrast formation is absorption that makes some limitations for imaging of the light density materials and what is more the resolution of these techniques is not better than 10-100 {mu}m. It was turned out that there is now way in which to overcome 1{mu}m or even sub-{mu}m resolution limit except phase contrast imaging. It is well known in optics that the phase contrast is realised when interference between reference wave front and transmitted through the sample take place. Examples of this imaging are: phase contrast microscopy suggested by Zernike and Gabor (in-line) holography. Both of this techniques: phase contrast x-ray microscopy and holography are successfully progressing now in soft x-ray region. For imaging in the hard X-rays to enhance the contrast and to be able to resolve phase variations across the beam the high degree of the time and more importantly spatial coherence is needed. Because of this it was reasonable that the perfect crystal optics was involved like Bonse-Hart interferometry, double-crystal and even triple-crystal set-up using Laue and Bragg geometry with asymmetrically cut crystals.

  4. Quantification of the kV X-ray imaging dose during real-time tumor tracking and from three- and four-dimensional cone-beam computed tomography in lung cancer patients using a Monte Carlo simulation.

    Science.gov (United States)

    Nakamura, Mitsuhiro; Ishihara, Yoshitomo; Matsuo, Yukinori; Iizuka, Yusuke; Ueki, Nami; Iramina, Hiraku; Hirashima, Hideaki; Mizowaki, Takashi

    2018-03-01

    Knowledge of the imaging doses delivered to patients and accurate dosimetry of the radiation to organs from various imaging procedures is becoming increasingly important for clinicians. The purposes of this study were to calculate imaging doses delivered to the organs of lung cancer patients during real-time tumor tracking (RTTT) with three-dimensional (3D), and four-dimensional (4D) cone-beam computed tomography (CBCT), using Monte Carlo techniques to simulate kV X-ray dose distributions delivered using the Vero4DRT. Imaging doses from RTTT, 3D-CBCT and 4D-CBCT were calculated with the planning CT images for nine lung cancer patients who underwent stereotactic body radiotherapy (SBRT) with RTTT. With RTTT, imaging doses from correlation modeling and from monitoring of imaging during beam delivery were calculated. With CBCT, doses from 3D-CBCT and 4D-CBCT were also simulated. The doses covering 2-cc volumes (D2cc) in correlation modeling were up to 9.3 cGy for soft tissues and 48.4 cGy for bone. The values from correlation modeling and monitoring were up to 11.0 cGy for soft tissues and 59.8 cGy for bone. Imaging doses in correlation modeling were larger with RTTT. On a single 4D-CBCT, the skin and bone D2cc values were in the ranges of 7.4-10.5 cGy and 33.5-58.1 cGy, respectively. The D2cc from 4D-CBCT was approximately double that from 3D-CBCT. Clinicians should Figure that the imaging dose increases the cumulative doses to organs.

  5. Radiation doses for X-ray diagnosis teeth in dental medicine

    International Nuclear Information System (INIS)

    Direkov, Lyubomir

    2009-01-01

    X-rays are the first ionizing radiation, which are applied in medicine for diagnostic radiology and X-ray therapy. While in the beginning they are mainly used for X-ray photos of the chest /lungs and in severe fractures of the limbs, then in recent years they are widely applied in diagnostics of teeth in dental medicine. Considering that caries is a widespread disease, both in children and adults, and it requires repeated x-ray photographs of the damaged teeth for the individual, the total radiation doses, which reflect on people from the X-rays are at high values. In order to reduce external exposure to other organs /mainly thyroid gland/ by X-ray pictures of teeth, it should be used with special lead aprons with large coefficient of reduction. Keywords: doses of radiation, X-ray machines, dental, x-ray pictures of teeth, protection sources

  6. X-ray image amplifying tube

    International Nuclear Information System (INIS)

    1977-01-01

    The photo electrons from the picture on the fluorescent input screen are amplified by an electron optical system and produce an intensified image on the output screen. This can be photographed and shown on a TV screen. The effects of stray magnetic fields are reduced by covering the input screen with a grating made of strips of ferromagnetic material such as μ metal. (T.S.E.T.)

  7. Determination of entrance skin dose from diagnostic X-ray of human ...

    African Journals Online (AJOL)

    patient during x-ray examination in Federal Medical Centre, Keffi in Nasarawa state, Nigeria. Entrance skin doses (ESDs) for a common type of x-ray procedures, namely chest AP/PA (anterior/posterior) were measured. A total of 200 data were collected from patients who were exposed to diagnostic X-ray during their routine ...

  8. Diffraction enhanced X-ray imaging of mammals crystalline lens

    International Nuclear Information System (INIS)

    Antunes, A.; Hoennicke, M.G.; Safatle, A.M.V.; Cusatis, C.; Moraes Barros, P.S.; Morelhao, S.L.

    2005-01-01

    Crystalline lenses are transparent biological materials where the organization of the lens fibers can also be affected by changes at molecular level, and therefore the structure and morphology of the tissue can be correlated to the loss of transparency of the lens. In this work, internal structure of mammal lenses regarding the long-range ordering of the fibers are investigated by diffraction enhanced X-ray imaging (DEI) radiography. Moreover, DEI and absorption X-ray synchrotron radiographs for healthy and cataractous crystalline lenses are compared. Significant differences in healthy and cataractous crystalline lenses are observed

  9. Gas microstrip detectors for X-ray tomographic flow imaging

    CERN Document Server

    Key, M J; Luggar, R D; Kundu, A

    2003-01-01

    A investigation into the suitability of gas microstrip detector technology for a high-speed industrial X-ray tomography system is reported. X-ray energies in the region 20-30 keV are well suited to the application, which involves imaging two-dimensional slices through gas/liquid multiphase pipeline flows for quantitative component fraction measurement. Stable operation over a period representing several hundred individual tomographic scans at gas gains of 500 is demonstrated using a Penning gas mixture of krypton/propylene.

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... up in shades of gray and air appears black. Until recently, x-ray images were maintained on ... Safety page for more information about radiation dose. Women should always inform their physician or x-ray ...

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... conditions. Imaging with x-rays involves exposing a part of the body to a small dose of ... body. Once it is carefully aimed at the part of the body being examined, an x-ray ...

  13. Structured scintillators for X-ray imaging with micrometre resolution

    DEFF Research Database (Denmark)

    Olsen, Ulrik Lund; Schmidt, Søren; Poulsen, Henning Friis

    2009-01-01

    A 3D X-ray detector for imaging of 30–200 keV photons is described. It comprises a stack of semitransparent structured scintillators, where each scintillator is a regular array of waveguides in silicon, and with pores filled with CsI. The performance of the detector is described theoretically...

  14. The hard x-ray imager onboard IXO

    Science.gov (United States)

    Nakazawa, Kazuhiro; Takahashi, Tadayuki; Limousin, Olivier; Kokubun, Motohide; Watanabe, Shin; Laurent, Philippe; Arnaud, Monique; Tajima, Hiroyasu

    2010-07-01

    The Hard X-ray Imager (HXI) is one of the instruments onboard International X-ray Observatory (IXO), to be launched into orbit in 2020s. It covers the energy band of 10-40 keV, providing imaging-spectroscopy with a field of view of 8 x 8 arcmin2. The HXI is attached beneath the Wide Field Imager (WFI) covering 0.1-15 keV. Combined with the super-mirror coating on the mirror assembly, this configuration provides observation of X-ray source in wide energy band (0.1-40.0 keV) simultaneously, which is especially important for varying sources. The HXI sensor part consists of the semiconductor imaging spectrometer, using Si in the medium energy detector and CdTe in the high energy detector as its material, and an active shield covering its back to reduce background in orbit. The HXI technology is based on those of the Japanese-lead new generation X-ray observatory ASTRO-H, and partly from those developed for Simbol-X. Therefore, the technological development is in good progress. In the IXO mission, HXI will provide a major assets to identify the nature of the object by penetrating into thick absorbing materials and determined the inherent spectral shape in the energy band well above the structure around Fe-K lines and edges.

  15. A gas pixel detector for X-ray imaging

    International Nuclear Information System (INIS)

    Bateman, J.E.; Connolly, J.F.

    1991-11-01

    A simple, robust form of gas pixel detector is discussed which is based on the use of electronic connector pins as the gain elements. With a rate capability of >10 5 counts/s per pin, an X-ray imaging detector system capable of counting at global rates of the order of 10 10 counts/s is foreseen. (author)

  16. Phase contrast imaging using a micro focus x-ray source

    Science.gov (United States)

    Zhou, Wei; Majidi, Keivan; Brankov, Jovan G.

    2014-09-01

    Phase contrast x-ray imaging, a new technique to increase the imaging contrast for the tissues with close attenuation coefficients, has been studied since mid 1990s. This technique reveals the possibility to show the clear details of the soft tissues and tumors in small scale resolution. A compact and low cost phase contrast imaging system using a conventional x-ray source is described in this paper. Using the conventional x-ray source is of great importance, because it provides the possibility to use the method in hospitals and clinical offices. Simple materials and components are used in the setup to keep the cost in a reasonable and affordable range.Tungsten Kα1 line with the photon energy 59.3 keV was used for imaging. Some of the system design details are discussed. The method that was used to stabilize the system is introduced. A chicken thigh bone tissue sample was used for imaging followed by the image quality, image acquisition time and the potential clinical application discussion. High energy x-ray beam can be used in phase contrast imaging. Therefore the radiation dose to the patients can be greatly decreased compared to the traditional x-ray radiography.

  17. Image quality and dose analysis for a PA chest X-ray: Comparison between AEC mode acquisition and manual mode using the 10 kVp ‘rule’

    International Nuclear Information System (INIS)

    Reis, Cláudia; Gonçalves, João; Klompmaker, Corrie; Bárbara, Ana Rita; Bloor, Chloe; Hegarty, Ryan; Lagrange, Tania; Temming, Noëlle; Sønnesyn, Mathilde; Røkeness, Henriette; Yamasathien, Amandine; Hogg, Peter

    2014-01-01

    Purpose: To compare the image quality and effective dose applying the 10 kVp rule with manual mode acquisition and AEC mode in PA chest X-ray. Method: 68 images (with and without lesions) were acquired using an anthropomorphic chest phantom using a Wolverson Arcoma X-ray unit. These images were compared against a reference image using the 2 alternative forced choice (2AFC) method. The effective dose (E) was calculated using PCXMC software using the exposure parameters and the DAP. The exposure index (lgM provided by Agfa systems) was recorded. Results: Exposure time decreases more when applying the 10 kVp rule with manual mode (50%–28%) when compared with automatic mode (36%–23%). Statistical differences for E between several ionization chambers' combinations for AEC mode were found (p = 0.002). E is lower when using only the right AEC ionization chamber. Considering the image quality there are no statistical differences (p = 0.348) between the different ionization chambers' combinations for AEC mode for images with no lesions. Considering lgM values, it was demonstrated that they were higher when the AEC mode was used compared to the manual mode. It was also observed that lgM values obtained with AEC mode increased as kVp value went up. The image quality scores did not demonstrate statistical significant differences (p = 0.343) for the images with lesions comparing manual with AEC mode. Conclusion: In general the E is lower when manual mode is used. By using the right AEC ionising chamber under the lung the E will be the lowest in comparison to other ionising chambers. The use of the 10 kVp rule did not affect the visibility of the lesions or image quality

  18. Luminescence imaging of water during irradiation of X-ray photons lower energy than Cerenkov- light threshold

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi; Koyama, Shuji; Komori, Masataka [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center (Japan)

    2016-10-01

    Luminescence imaging of water using X-ray photon irradiation at energy lower than maximum energy of ~200 keV is thought to be impossible because the secondary electrons produced in this energy range do not emit Cerenkov- light. Contrary to this consensus assumption, we show that the luminescence imaging of water can be achieved by X-ray irradiation at energy lower than 120 keV. We placed water phantoms on a table with a conventional X-ray imaging system, and luminescence images of these phantoms were measured with a high-sensitivity, cooled charge coupled device (CCD) camera during X-ray photon irradiation at energy below 120 keV. We also carried out such imaging of an acrylic block and plastic scintillator. The luminescence images of water phantoms taken during X-ray photon irradiation clearly showed X-ray photon distribution. The intensity of the X-ray photon images of the phantom increased almost proportionally to the number of X-ray irradiations. Lower-energy X-ray photon irradiation showed lower-intensity luminescence at the deeper parts of the phantom due to the higher X-ray absorption in the water phantom. Furthermore, lower-intensity luminescence also appeared at the deeper parts of the acrylic phantom due to its higher density than water. The intensity of the luminescence for water was 0.005% of that for plastic scintillator. Luminescence imaging of water during X-ray photon irradiation at energy lower than 120 keV was possible. This luminescence imaging method is promising for dose estimation in X-ray imaging systems.

  19. Luminescence imaging of water during irradiation of X-ray photons lower energy than Cerenkov- light threshold

    Science.gov (United States)

    Yamamoto, Seiichi; Koyama, Shuji; Komori, Masataka; Toshito, Toshiyuki

    2016-10-01

    Luminescence imaging of water using X-ray photon irradiation at energy lower than maximum energy of 200 keV is thought to be impossible because the secondary electrons produced in this energy range do not emit Cerenkov- light. Contrary to this consensus assumption, we show that the luminescence imaging of water can be achieved by X-ray irradiation at energy lower than 120 keV. We placed water phantoms on a table with a conventional X-ray imaging system, and luminescence images of these phantoms were measured with a high-sensitivity, cooled charge coupled device (CCD) camera during X-ray photon irradiation at energy below 120 keV. We also carried out such imaging of an acrylic block and plastic scintillator. The luminescence images of water phantoms taken during X-ray photon irradiation clearly showed X-ray photon distribution. The intensity of the X-ray photon images of the phantom increased almost proportionally to the number of X-ray irradiations. Lower-energy X-ray photon irradiation showed lower-intensity luminescence at the deeper parts of the phantom due to the higher X-ray absorption in the water phantom. Furthermore, lower-intensity luminescence also appeared at the deeper parts of the acrylic phantom due to its higher density than water. The intensity of the luminescence for water was 0.005% of that for plastic scintillator. Luminescence imaging of water during X-ray photon irradiation at energy lower than 120 keV was possible. This luminescence imaging method is promising for dose estimation in X-ray imaging systems.

  20. Effect of basic fog of medical x-ray films on image quality and patient dose-method of evaluation and steps to control

    International Nuclear Information System (INIS)

    Bohra, Reena; Nair, C.P.R.; Jayalakshmi, V.; Govindarajan, K.N.; Bhatt, B.C.

    2003-01-01

    Unacceptable basic fog of medical x-ray films has been reported recently from many hospitals. The paper presents the effect of basic fog on radiographic quality of films like sensitivity (speed), contrast and maximum density (DMax). Several batches of general- purpose medical x-ray films from five different manufacturers were studied to evaluate batch-to-batch variation in basic fog. Increase in basic fog with aging of films was also evaluated. Reasons for increased basic fog observed in the film processing facilities of a few hospitals were analysed. Factors responsible for increase in basic fog and the steps to control it have been discussed

  1. Applications of phase-contrast x-ray imaging to medicine using an x-ray interferometer

    Science.gov (United States)

    Momose, Atsushi; Yoneyama, Akio; Takeda, Tohoru; Itai, Yuji; Tu, Jinhong; Hirano, Keiichi

    1999-10-01

    We are investigating possible medical applications of phase- contrast X-ray imaging using an X-ray interferometer. This paper introduces the strategy of the research project and the present status. The main subject is to broaden the observation area to enable in vivo observation. For this purpose, large X-ray interferometers were developed, and 2.5 cm X 1.5 cm interference patterns were generated using synchrotron X-rays. An improvement of the spatial resolution is also included in the project, and an X-ray interferometer designed for high-resolution phase-contrast X-ray imaging was fabricated and tested. In parallel with the instrumental developments, various soft tissues are observed by phase- contrast X-ray CT to find correspondence between the generated contrast and our histological knowledge. The observation done so far suggests that cancerous tissues are differentiated from normal tissues and that blood can produce phase contrast. Furthermore, this project includes exploring materials that modulate phase contrast for selective imaging.

  2. Recent developments in X-ray imaging detectors

    CERN Document Server

    Moy, J P

    2000-01-01

    The replacement of the radiographic film in medical imaging has been the driving force in X-ray imaging developments. It requires a approx 40 cm wide detector to cover all examinations, an equivalent noise level of 1-5 X-ray quanta per pixel, and spatial resolution in the range 100-150 mu m. The need for entirely electronic imaging equipments has fostered the development of many X-ray detectors, most of them based on an array of amorphous silicon pixels, which is the only technology capable to achieve such large areas. Essentially, two concepts have been implemented: - intermediate conversion of X-rays to light by a scintillator, detected by an array of light sensitive pixels, comprising a photodiode and a switching device, either a TFT or a diode. - conversion into electron-hole pairs in a photoconductor, collected by an array of electrodes and switches. In both cases, charge amplifiers read the generated charges line by line. Scintillator and photoconductor-based systems are now close to production. They ac...

  3. Electronic roentgenographic images in presurgical X-ray diagnostics

    International Nuclear Information System (INIS)

    Haendle, J.; Hohmann, D.; Maass, W.; Siemens A.G., Erlangen

    1981-01-01

    An essential part of radiation exposure in surgery is due to devices and results from the required radiation time interval for continuous X-ray play-back up to the point at which all diagnostically relevant information can be retrieved from the screening image. With single-image storage and short exposure times as well as instant image play-back, this superfluous i.e. redundant radiation can be avoided. The electronic X-ray image is realized by means of a laboratory prototype and evaluated in hospitals. There is a report on clinical results and new technical developments. Remarkable are: the high radiation reduction that could be obtained, the problem - free instant image technique, and especially the advantages of automated exposure in direct film settings. The positive results yield the basis for the product development. (orig./MG) [de

  4. Design and image-quality performance of high resolution CMOS-based X-ray imaging detectors for digital mammography

    Science.gov (United States)

    Cha, B. K.; Kim, J. Y.; Kim, Y. J.; Yun, S.; Cho, G.; Kim, H. K.; Seo, C.-W.; Jeon, S.; Huh, Y.

    2012-04-01

    In digital X-ray imaging systems, X-ray imaging detectors based on scintillating screens with electronic devices such as charge-coupled devices (CCDs), thin-film transistors (TFT), complementary metal oxide semiconductor (CMOS) flat panel imagers have been introduced for general radiography, dental, mammography and non-destructive testing (NDT) applications. Recently, a large-area CMOS active-pixel sensor (APS) in combination with scintillation films has been widely used in a variety of digital X-ray imaging applications. We employed a scintillator-based CMOS APS image sensor for high-resolution mammography. In this work, both powder-type Gd2O2S:Tb and a columnar structured CsI:Tl scintillation screens with various thicknesses were fabricated and used as materials to convert X-ray into visible light. These scintillating screens were directly coupled to a CMOS flat panel imager with a 25 × 50 mm2 active area and a 48 μm pixel pitch for high spatial resolution acquisition. We used a W/Al mammographic X-ray source with a 30 kVp energy condition. The imaging characterization of the X-ray detector was measured and analyzed in terms of linearity in incident X-ray dose, modulation transfer function (MTF), noise-power spectrum (NPS) and detective quantum efficiency (DQE).

  5. Digital imaging system in mammography with X-ray of two different energies

    International Nuclear Information System (INIS)

    Swientek, K.; Dabrowski, W.; Grybos, P.; Wiacek, P.; Cabal Rodrigez, A. E.; Sanchez, C.C.; Gambaccini, M.; Gaitan, J.L.; Prino, F.; Ramello, L.

    2005-01-01

    The progress in nuclear medicine stimulates the higher quality of image processing at diminished radiation dose. In the presented apparatus system Si-microstrip detector with two-thresholds multichannel amplitude analyzer have been applied. Data acquisition system evaluates simultaneously images for two X-ray beams of different energies following the Bragg reflection of the primary beam from the mosaic crystal. The contrast cancellation technique has been tested using the simple mammography phantom. An efficacy of this method suitable for medical imaging could be significantly increased using an intensive X-ray source and sensitive detectors

  6. Imaging X-Ray Polarimetry Explorer (IXPE) Risk Management

    Science.gov (United States)

    Alexander, Cheryl; Deininger, William D.; Baggett, Randy; Primo, Attina; Bowen, Mike; Cowart, Chris; Del Monte, Ettore; Ingram, Lindsey; Kalinowski, William; Kelley, Anthony; hide

    2018-01-01

    The Imaging X-ray Polarimetry Explorer (IXPE) project is an international collaboration to build and fly a polarization sensitive X-ray observatory. The IXPE Observatory consists of the spacecraft and payload. The payload is composed of three X-ray telescopes, each consisting of a mirror module optical assembly and a polarization-sensitive X-ray detector assembly; a deployable boom maintains the focal length between the optical assemblies and the detectors. The goal of the IXPE Mission is to provide new information about the origins of cosmic X-rays and their interactions with matter and gravity as they travel through space. IXPE will do this by exploiting its unique capability to measure the polarization of X-rays emitted by cosmic sources. The collaboration for IXPE involves national and international partners during design, fabrication, assembly, integration, test, and operations. The full collaboration includes NASA Marshall Space Flight Center (MSFC), Ball Aerospace, the Italian Space Agency (ASI), the Italian Institute of Astrophysics and Space Planetology (IAPS)/Italian National Institute of Astrophysics (INAF), the Italian National Institute for Nuclear Physics (INFN), the University of Colorado (CU) Laboratory for Atmospheric and Space Physics (LASP), Stanford University, McGill University, and the Massachusetts Institute of Technology. The goal of this paper is to discuss risk management as it applies to the IXPE project. The full IXPE Team participates in risk management providing both unique challenges and advantages for project risk management. Risk management is being employed in all phases of the IXPE Project, but is particularly important during planning and initial execution-the current phase of the IXPE Project. The discussion will address IXPE risk strategies and responsibilities, along with the IXPE management process which includes risk identification, risk assessment, risk response, and risk monitoring, control, and reporting.

  7. Ultrahigh-speed X-ray imaging of hypervelocity projectiles

    Science.gov (United States)

    Miller, Stuart; Singh, Bipin; Cool, Steven; Entine, Gerald; Campbell, Larry; Bishel, Ron; Rushing, Rick; Nagarkar, Vivek V.

    2011-08-01

    High-speed X-ray imaging is an extremely important modality for healthcare, industrial, military and research applications such as medical computed tomography, non-destructive testing, imaging in-flight projectiles, characterizing exploding ordnance, and analyzing ballistic impacts. We report on the development of a modular, ultrahigh-speed, high-resolution digital X-ray imaging system with large active imaging area and microsecond time resolution, capable of acquiring at a rate of up to 150,000 frames per second. The system is based on a high-resolution, high-efficiency, and fast-decay scintillator screen optically coupled to an ultra-fast image-intensified CCD camera designed for ballistic impact studies and hypervelocity projectile imaging. A specially designed multi-anode, high-fluence X-ray source with 50 ns pulse duration provides a sequence of blur-free images of hypervelocity projectiles traveling at speeds exceeding 8 km/s (18,000 miles/h). This paper will discuss the design, performance, and high frame rate imaging capability of the system.

  8. Flexible digital x-ray technology for far-forward remote diagnostic and conformal x-ray imaging applications

    Science.gov (United States)

    Smith, Joseph; Marrs, Michael; Strnad, Mark; Apte, Raj B.; Bert, Julie; Allee, David; Colaneri, Nicholas; Forsythe, Eric; Morton, David

    2013-05-01

    Today's flat panel digital x-ray image sensors, which have been in production since the mid-1990s, are produced exclusively on glass substrates. While acceptable for use in a hospital or doctor's office, conventional glass substrate digital x-ray sensors are too fragile for use outside these controlled environments without extensive reinforcement. Reinforcement, however, significantly increases weight, bulk, and cost, making them impractical for far-forward remote diagnostic applications, which demand rugged and lightweight x-ray detectors. Additionally, glass substrate x-ray detectors are inherently rigid. This limits their use in curved or bendable, conformal x-ray imaging applications such as the non-destructive testing (NDT) of oil pipelines. However, by extending low-temperature thin-film transistor (TFT) technology previously demonstrated on plastic substrate- based electrophoretic and organic light emitting diode (OLED) flexible displays, it is now possible to manufacture durable, lightweight, as well as flexible digital x-ray detectors. In this paper, we discuss the principal technical approaches used to apply flexible display technology to two new large-area flexible digital x-ray sensors for defense, security, and industrial applications and demonstrate their imaging capabilities. Our results include a 4.8″ diagonal, 353 x 463 resolution, flexible digital x-ray detector, fabricated on a 6″ polyethylene naphthalate (PEN) plastic substrate; and a larger, 7.9″ diagonal, 720 x 640 resolution, flexible digital x-ray detector also fabricated on PEN and manufactured on a gen 2 (370 x 470 mm) substrate.

  9. Basic studies in X-ray radiography and imaging techniques

    International Nuclear Information System (INIS)

    Vaidya, Paresh R.

    2000-01-01

    The aim of this research was to study the basic characteristics related to a new branch of radiography viz. the micro-focal radiography. The most important among them was to find methods of measurement of focal spot size of these X-ray sources. It is important to accomplish this because the design of such units is specifically meant to produce very fine source size. To this end. first the process of radiography test was introduced. Among other things. various properties of an image and image forming systems (like PSF, LSF, MTF etc.) were introduced and explained. Methods used for microfocus measurement of focal spot size in conventional units were reviewed. It was shown how they are not suitable for microfocal tubes. Next the microfocus X-ray unit meant for the study was installed and commissioned. Features which are different from conventional X-ray units were observed more carefully. Data was collected and analyzed for various aspects. Procedure for focussing the electron beam while getting the feed back about beam diameter from the oscilloscope was established by experiments. In addition, influence of change in tube voltage and tube current on the focal spot size was studied. Relationship between tube current and target current vis-a-vis focus size was established. Radiation zone was determined. Focal spot size was qualitatively compared with that of a conventional X-ray unit by taking radiographs of different wire meshes at different magnifications by both the units

  10. Effects of tube potential and scatter rejection on image quality and effective dose in digital chest X-ray examination: An anthropomorphic phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, D.J., E-mail: daniel.shaw@christie.nhs.uk [Diagnostic Radiology, Department of Medical Physics and Engineering, Leeds Teaching Hospitals, Leeds General Infirmary, Great George Street, Leeds LS1 3EX (United Kingdom); Crawshaw, I. [Diagnostic X-ray Department, York Teaching Hospital NHS Foundation Trust, The York Hospital, Wigginton Road, York YO31 8HE (United Kingdom); Rimmer, S. D. [Diagnostic Radiology, Department of Medical Physics and Engineering, Leeds Teaching Hospitals, Leeds General Infirmary, Great George Street, Leeds LS1 3EX (United Kingdom)

    2013-11-15

    Objectives: The purpose of this study was to investigate the effects of tube potential and scatter rejection techniques on image quality of digital posteroanterior (PA) chest radiographs. Methods: An anthropomorphic phantom was imaged using a range of tube potentials (81–125 kV{sub p}) without scatter rejection, with an anti-scatter grid, and using a 10 cm air gap. Images were anonymised and randomised before being evaluated using a visual graded analysis (VGA) method. Results: The effects of tube potential on image quality were found to be negligible (p > 0.63) for the flat panel detector (FPD). Decreased image quality (p = 0.031) was noted for 125 kV{sub p} relative to 109 kV{sub p}, though no difference was noted for any of the other potentials (p > 0.398) for computed radiography (CR). Both scatter rejection techniques improved image quality (p < 0.01). For FPD imaging the anti-scatter grid offered slightly improved image quality relative to the air gap (p = 0.038) but this was not seen for CR (p = 0.404). Conclusions: For FPD chest imaging of the anthropomorphic phantom there was no dependence of image quality on tube potential. Scatter rejection improved image quality, with the anti-scatter grid giving greater improvements than an air-gap, but at the expense of increased effective dose. CR imaging of the chest phantom demonstrated negligible dependence on tube potential except at 125 kV{sub p}. Scatter rejection improved image quality, but with no difference found between techniques. The air-gap resulted in a smaller increase in effective dose than the anti-scatter grid and would be the preferred scatter rejection technique.

  11. Measurements of X ray absorbed doses to dental patients in two dental X ray units in Nigeria

    International Nuclear Information System (INIS)

    Ogundare, F.O.; Oni, O.M.; Balogun, F.A.

    2002-01-01

    Measurements of absorbed doses from radiographic examinations to various anatomical sites in the head and neck of patients with an average age of 45 years using intra-oral dental radiography have been carried out. LiF (TLD-100) dosemeters were used for the measurements of the absorbed dose. The measured absorbed doses to the various anatomical sites in the two units are reported, discussed and compared with results from the literature. Quality control measurements were also performed using a Victoreen quality control test device on the X ray units. The tube voltage accuracies for the two units were found to be within acceptable limits (less than ±10%). On the other hand the exposure time accuracies for these units have large deviations (>20%). These results and those that have been reported in the literature may be an indication that high patient doses are common in most dental X ray centres and countries. As a result of this, regular compliance and performance checks of dental diagnostic X ray equipment are essential in order to ensure proper performance and to minimise unnecessary patient and operator doses. (author)

  12. New developments in simulating X-ray phase contrast imaging

    International Nuclear Information System (INIS)

    Peterzol, A.; Berthier, J.; Duvauchelle, P.; Babot, D.; Ferrero, C.

    2007-01-01

    A deterministic algorithm simulating phase contrast (PC) x-ray images for complex 3- dimensional (3D) objects is presented. This algorithm has been implemented in a simulation code named VXI (Virtual X-ray Imaging). The physical model chosen to account for PC technique is based on the Fresnel-Kirchhoff diffraction theory. The algorithm consists mainly of two parts. The first one exploits the VXI ray-tracing approach to compute the object transmission function. The second part simulates the PC image due to the wave front distortion introduced by the sample. In the first part, the use of computer-aided drawing (CAD) models enables simulations to be carried out with complex 3D objects. Differently from the VXI original version, which makes use of an object description via triangular facets, the new code requires a more 'sophisticated' object representation based on Non-Uniform Rational B-Splines (NURBS). As a first step we produce a spatial high resolution image by using a point and monochromatic source and an ideal detector. To simulate the polychromatic case, the intensity image is integrated over the considered x-ray energy spectrum. Then, in order to account for the system spatial resolution properties, the high spatial resolution image (mono or polychromatic) is convolved with the total point spread function of the imaging system under consideration. The results supplied by the presented algorithm are examined with the help of some relevant examples. (authors)

  13. X-ray volume imaging in bladder radiotherapy verification

    International Nuclear Information System (INIS)

    Henry, Ann M.; Stratford, Julia; McCarthy, Claire; Davies, Julie; Sykes, Jonathan R.; Amer, Ali; Marchant, Tom; Cowan, Richard; Wylie, James; Logue, John; Livsey, Jacqueline; Khoo, Vincent S.; Moore, Chris; Price, Pat

    2006-01-01

    Purpose: To assess the clinical utility of X-ray volume imaging (XVI) for verification of bladder radiotherapy and to quantify geometric error in bladder radiotherapy delivery. Methods and Materials: Twenty subjects undergoing conformal bladder radiotherapy were recruited. X-ray volume images and electronic portal images (EPIs) were acquired for the first 5 fractions and then once weekly. X-ray volume images were co-registered with the planning computed tomography scan and clinical target volume coverage assessed in three dimensions (3D). Interfraction bladder volume change was described by quantifying changes in bladder volume with time. Bony setup errors were compared from both XVI and EPI. Results: The bladder boundary was clearly visible on coronal XVI views in nearly all images, allowing accurate 3D treatment verification. In 93.5% of imaged fractions, the clinical target volume was within the planning target volume. Most subjects displayed consistent bladder volumes, but 25% displayed changes that could be predicted from the first three XVIs. Bony setup errors were similar whether calculated from XVI or EPI. Conclusions: Coronal XVI can be used to verify 3D bladder radiotherapy delivery. Image-guided interventions to reduce geographic miss and normal tissue toxicity are feasible with this technology

  14. Clinical implementation of x-ray phase-contrast imaging: Theoretical foundations and design considerations

    International Nuclear Information System (INIS)

    Wu Xizeng; Liu Hong

    2003-01-01

    Theoretical foundation and design considerations of a clinical feasible x-ray phase contrast imaging technique were presented in this paper. Different from the analysis of imaging phase object with weak absorption in literature, we proposed a new formalism for in-line phase-contrast imaging to analyze the effects of four clinically important factors on the phase contrast. These are the body parts attenuation, the spatial coherence of spherical waves from a finite-size focal spot, and polychromatic x-ray and radiation doses to patients for clinical applications. The theory presented in this paper can be applied widely in diagnostic x-ray imaging procedures. As an example, computer simulations were conducted and optimal design parameters were derived for clinical mammography. The results of phantom experiments were also presented which validated the theoretical analysis and computer simulations

  15. Coding aperture applied to X-ray imaging

    International Nuclear Information System (INIS)

    Brunol, J.; Sauneuf, R.; Gex, J.P.

    1980-05-01

    We present some X-ray images of grids and plasmas. These images were obtained by using a single circular slit (annular code) as coding aperture and a computer decoding process. The experimental resolution is better than 10μm and it is expected to be in the order of 2 or 3 μm with the same code and an improved decoding process

  16. Operation of a separated-type x-ray interferometer for phase-contrast x-ray imaging

    Science.gov (United States)

    Yoneyama, Akio; Momose, Atsushi; Seya, Eiichi; Hirano, Keiichi; Takeda, Tohoru; Itai, Yuji

    1999-12-01

    Aiming at large-area phase-contrast x-ray imaging, a separated-type x-ray interferometer system was designed and developed to produce 25×20 mm interference patterns. The skew-symmetric optical system was adopted because of the feasibility of alignment. The rotation between the separated crystal blocks was controlled within a drift of 0.06 nrad using a feedback positioning system. This interferometer generated a 25×15 mm interference pattern with 0.07 nm synchrotron x-rays. A slice of a rabbit's kidney was observed, and its tubular structure could be revealed in a measured phase map.

  17. Digital image acquisition in the X-ray diagnostics. Its influence on the patients' exposure

    International Nuclear Information System (INIS)

    Hoberg, Bernd; Voigt, Stefan

    2012-01-01

    Radiation exposure in the classical X-ray diagnostics was continuously reduced during the past years. The annual report 2009 of the Bundesamt fuer Strahlenschutz (BfS) shows that 46% of the radiological examinations in Germany concern the skeleton, the lungs and the digestive and urogenital tract. The respective radiation dose is only 20% of the total dose of the public from X-ray diagnostic measures. Considering computerized tomography, angiography and interventional radiology, that amount to about 10% of the radiological examinations, their dose percentage reaches about 80%. Therefore, the emphasis of modern radiation protection has to be targeted to digital techniques in the future X-ray diagnostics. The authors describe digital detectors, direct and indirect digitalized image receivers, flat-panel detectors and dynamic detectors.

  18. Trends in NOAA Solar X-ray Imager Performance

    Science.gov (United States)

    Hill, Steven M.; Darnell, John A.; Seaton, Daniel B.

    2016-05-01

    NOAA has provided operational soft X-ray imaging of the sun since the early 2000’s. After 15 years of observations by four different telescopes, it is appropriate to examine the data in terms of providing consistent context for scientific missions. In particular, this presentation examines over 7 million GOES Solar X-ray Imager (SXI) images for trends in performance parameters including dark current, response degradation, and inter-calibration. Because observations from the instrument have overlapped not only with each other, but also with research observations like Yohkoh SXT and Hinode XRT, relative performance comparisons can be made. The first GOES Solar X-ray Imager was launched in 2001 and entered operations in 2003. The current SXIs will remain in operations until approximately 2020, when a new series of Solar (extreme-)Ultraviolet Imagers (SUVIs) will replace them as the current satellites reach their end of life. In the sense that the SXIs are similar to Yokoh’s SXT and Hinode’s XRT, the SUVI instruments will be similar to SOHO’s EIT and SDO’s AIA. The move to narrowband EUV imagers will better support eventual operational estimation of plasma conditions. While NOAA’s principal use of these observations is real-time space weather forecasting, they will continue to provide a reliable context measurement for researchers for decades to come.

  19. Fast X-ray imaging of cavitating flows

    Energy Technology Data Exchange (ETDEWEB)

    Khlifa, Ilyass; Fuzier, Sylvie; Roussette, Olivier [Arts et Metiers ParisTech, Lille (France); Vabre, Alexandre [CEA Saclay, Gif-sur-Yvette (France); Hocevar, Marko [Faculty of Mechanical Engineering, University of Ljubljana, Ljubljana (Slovenia); Fezzaa, Kamel [Argonne National Laboratory, Advanced Photon Source, Lemont, IL (United States); Coutier-Delgosha, Olivier [Virginia Tech, Kevin T. Crofton Department of Aerospace and Ocean Engineering, Blacksburg, VA (United States)

    2017-11-15

    A new method based on ultra-fast X-ray imaging was developed in this work for the investigation of the dynamics and the structures of complex two-phase flows. In this paper, cavitation was created inside a millimetric 2D Venturi-type test section, while seeding particles were injected into the flow. Thanks to the phase-contrast enhancement technique provided by the APS (Advanced Photon Source) synchrotron beam, high definition X-ray images of the complex cavitating flows were obtained. These images contain valuable information about both the liquid and the gaseous phases. By means of image processing, the two phases were separated, and velocity fields of each phase were, therefore, calculated using image cross-correlations. The local vapour volume fractions were also obtained, thanks to the local intensity levels within the recorded images. These simultaneous measurements, provided by this new technique, afford more insight into the structure and the dynamic of two-phase flows as well as the interactions between them, and hence enable to improve our understanding of their behaviour. In the case of cavitating flows inside a Venturi-type test section, the X-ray measurements demonstrate, for the first time, the presence of significant slip velocities between the phases within sheet cavities for both steady and unsteady flow configurations. (orig.)

  20. High Resolution Energetic X-ray Imager (HREXI)

    Science.gov (United States)

    Grindlay, Jonathan

    We propose to design and build the first imaging hard X-ray detector system that incorporates 3D stacking of closely packed detector readouts in finely-spaced imaging arrays with their required data processing and control electronics. In virtually all imaging astronomical detectors, detector readout is done with flex connectors or connections that are not vertical but rather horizontal , requiring loss of focal plane area. For high resolution pixel detectors needed for high speed event-based X-ray imaging, from low energy applications (CMOS) with focusing X-ray telescopes, to hard X-ray applications with pixelated CZT for large area coded aperture telescopes, this new detector development offers great promise. We propose to extend our previous and current APRA supported ProtoEXIST program that has developed the first large area imaging CZT detectors and demonstrated their astrophysical capabilities on two successful balloon flight to a next generation High Resolution Energetic X-ray Imager (HREXI), which would incorporate microvia technology for the first time to connect the readout ASIC on each CZT crystal directly to its control and data processing system. This 3-dimensional stacking of detector and readout/control system means that large area (>2m2) imaging detector planes for a High Resolution Wide-field hard X-ray telescope can be built with initially greatly reduced detector gaps and ultimately with no gaps. This increases detector area, efficiency, and simplicity of detector integration. Thus higher sensitivity wide-field imagers will be possible at lower cost. HREXI will enable a post-Swift NASA mission such as the EREXS concept proposed to PCOS to be conducted as a future MIDEX mission. This mission would conduct a high resolution (<2 arcmin) , broad band (5 200 keV) hard X-ray survey of black holes on all scales with ~10X higher sensitivity than Swift. In the current era of Time Domain Astrophysics, such a survey capability, in conjunction with a n

  1. The Imaging X-Ray Polarimetry Explorer (IXPE): Overview

    Science.gov (United States)

    O'Dell, Steve; Weisskopf, M.; Soffitta, P.; Baldini, L.; Bellazzini, R.; Costa, E.; Elsner, R.; Kaspi, V.; Kolodziejczak, J.; Latronico, L.; hide

    2017-01-01

    Mission background: Imaging x-ray polarimetry in 2–8 kiloelectronvolt band; NASA Astrophysics Small Explorer (SMEX) selected in 2017 January. Orbit: Pegasus-XL (airborne) launch in 2021, from Kwajalein; Equatorial circular orbit at greater than or approximately equal to 540 kilometers (620 kilometers, goal) altitude. Flight system: Spacecraft, payload structure, and integration by Ball Aerospace - Deployable payload boom from Orbital-ATK, under contract to Ball; X-ray Mirror Module Assemblies by NASA/MSFC; X-ray (polarization-sensitive) Instruments by IAPS/INAF (Istituto di Astrofisica e Planetologia Spaziali / Istituto Nazionale di Astrofisica) and INFN (Istituto Nazionale di Fisica Nucleare). Ground system: ASI (Agenzia Spaziale Italiana) Malindi ground station, with Singapore backup; Mission Operations Center at LASP (Laboratory for Atmospheric and Space Physics, University of Colorado); Science Operations Center at NASA/MSFC; Data archive at HEASARC (High Energy Astrophysics Science Archive Research Center), (NASA/GSFC), mirror at ASI Data Center. Science: Active galactic nuclei; Microquasars; Radio pulsars and pulsar wind nebulae; Supernova remnants; Magnetars; Accreting x-ray pulsars.

  2. Direct view panel type X-ray image intensifier tube

    International Nuclear Information System (INIS)

    Yang, S.-P.; Robbins, C.D.; Merrit, E.

    1977-01-01

    A panel shaped, proximity type, X-ray image intensifier tube for medical X-ray fluoroscopy use is described. It has all linear components and yet a high brightness gain, in excess of 4,000 cd-sec/m 2 -R, the tube being comprised of a rugged metallic tube envelope, an inwardly concave metallic input window, a directly viewable full size output display screen, and a scintillator-photocathode screen having a thickness of at least 200 microns for a high X-ray photon utilization ability as well as X-ray stopping power, the scintillator-photocathode screen being suspended on insulators within the envelope and in between the input window and the output screen. The scintillator-photocathode screen is spaced from the output screen by at least 8mm to allow the application of a high negative potential at the scintillator-photocathode screen with respect to the output screen for high gain with low field emission, since all of the remaining components within the tube envelope are at neutral potential with respect to the output display screen. (Auth.)

  3. X-ray imaging bilinear staggered GaAs detectors

    Energy Technology Data Exchange (ETDEWEB)

    Achmadullin, R.A.; Dvoryankin, V.F. E-mail: vfd217@ire216.msk.su; Dvoryankina, G.G.; Dikaev, Y.M.Yu.M.; Krikunov, A.I.; Kudryashov, A.A.; Panova, T.M.; Petrov, A.G.; Telegin, A.A

    2004-09-21

    The multichannel bilinear X-ray detector based on epitaxial GaAs structures is developed to obtain a digital X-ray image. Each detector operates in photovoltaic mode without reverse bias that enables almost complete elimination of detector noise arising due to leakage currents. The sensitivity range of the epitaxial GaAs photovoltaic X-ray detector covers the effective energies from 8 to 120 keV. A maximum response of the detector operating in the short-circuit mode was observed at an energy of 35 keV and amounted to 30 {mu}A min/(Gy cm{sup 2}). The multichannel detector was made of 1024 pixels with pitch of 0.8 mm. The spatial resolution of double staggered sensor row is twice as high as the resolution of that of single sensor row with the same pitch. Measured spatial resolution is 1.2 line-pairs/mm, contrast sensitivity not worse 1% and dynamic range defined as the ratio of maximum detectable X-ray signal to electronic noise level more than 2000 are received.

  4. X-ray imaging bilinear staggered GaAs detectors

    International Nuclear Information System (INIS)

    Achmadullin, R.A.; Dvoryankin, V.F.; Dvoryankina, G.G.; Dikaev, Y.M.Yu.M.; Krikunov, A.I.; Kudryashov, A.A.; Panova, T.M.; Petrov, A.G.; Telegin, A.A.

    2004-01-01

    The multichannel bilinear X-ray detector based on epitaxial GaAs structures is developed to obtain a digital X-ray image. Each detector operates in photovoltaic mode without reverse bias that enables almost complete elimination of detector noise arising due to leakage currents. The sensitivity range of the epitaxial GaAs photovoltaic X-ray detector covers the effective energies from 8 to 120 keV. A maximum response of the detector operating in the short-circuit mode was observed at an energy of 35 keV and amounted to 30 μA min/(Gy cm 2 ). The multichannel detector was made of 1024 pixels with pitch of 0.8 mm. The spatial resolution of double staggered sensor row is twice as high as the resolution of that of single sensor row with the same pitch. Measured spatial resolution is 1.2 line-pairs/mm, contrast sensitivity not worse 1% and dynamic range defined as the ratio of maximum detectable X-ray signal to electronic noise level more than 2000 are received

  5. X-ray beam splitting design for concurrent imaging at hard X-ray FELs and synchrotron facilities

    Czech Academy of Sciences Publication Activity Database

    Oberta, Peter; Mokso, R.

    2013-01-01

    Roč. 729, NOV (2013), s. 85-89 ISSN 0168-9002 R&D Projects: GA MPO FR-TI1/412 Institutional research plan: CEZ:AV0Z10100522 Keywords : diffractive-refractive optics * hard X-ray FEL * X-ray imaging Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.316, year: 2013 http://www.sciencedirect.com/science/article/pii/S0168900213009613

  6. Possible radiation dose reduction by using digital X-ray equipment

    International Nuclear Information System (INIS)

    Horvathova, M.; Nikodemova, D.; Prikazska, M.

    2001-01-01

    The radiation load of population all over the world from medical examinations clearly demonstrates the importance of the introduction of the quality assurance and quality control programmes into the activities of radiology departments. The basic aim of quality assurance program is to ensure that the radiation dose is kept as low as reasonably practicable while still providing an adequate image quality. As many other fields, the rapid development of techniques brought change-over from the conventional analogue technique to the digital technique. In this process, the conventional X-ray film is being abandoned and images are being viewed on either laser film or monitor. The main advantages of using digital equipment lay in improved image quality and diagnostic accuracy through digital image processing, reduction in patients exposure, cost reduction by reduction of the film usage, more efficient storage and retrieval of radiographic images through picture archiving. Several studies that have been conducted for comparison of various diagnostic examinations show , that there is potential for dose saving in the digital image intensifier technique. The aim of this study was to compare measured values of dose-area product for colon investigations using different X-ray equipment types, two digital and two analogue. Our material consisted of 169 randomly selected patients, 115 of them were examined with digital equipment and 54 patients with the analogue equipment. The obtained results have confirmed the dose reduction and increase of diagnostic accuracy when using the digital equipment, with the added benefit of a good image quality. (authors)

  7. Patient size and x-ray technique factors in head computed tomography examinations. I. Radiation doses

    International Nuclear Information System (INIS)

    Huda, Walter; Lieberman, Kristin A.; Chang, Jack; Roskopf, Marsha L.

    2004-01-01

    We investigated how patient age, size and composition, together with the choice of x-ray technique factors, affect radiation doses in head computed tomography (CT) examinations. Head size dimensions, cross-sectional areas, and mean Hounsfield unit (HU) values were obtained from head CT images of 127 patients. For radiation dosimetry purposes patients were modeled as uniform cylinders of water. Dose computations were performed for 18x7 mm sections, scanned at a constant 340 mAs, for x-ray tube voltages ranging from 80 to 140 kV. Values of mean section dose, energy imparted, and effective dose were computed for patients ranging from the newborn to adults. There was a rapid growth of head size over the first two years, followed by a more modest increase of head size until the age of 18 or so. Newborns have a mean HU value of about 50 that monotonically increases with age over the first two decades of life. Average adult A-P and lateral dimensions were 186±8 mm and 147±8 mm, respectively, with an average HU value of 209±40. An infant head was found to be equivalent to a water cylinder with a radius of ∼60 mm, whereas an adult head had an equivalent radius 50% greater. Adult males head dimensions are about 5% larger than for females, and their average x-ray attenuation is ∼20 HU greater. For adult examinations performed at 120 kV, typical values were 32 mGy for the mean section dose, 105 mJ for the total energy imparted, and 0.64 mSv for the effective dose. Increasing the x-ray tube voltage from 80 to 140 kV increases patient doses by about a factor of 5. For the same technique factors, mean section doses in infants are 35% higher than in adults. Energy imparted for adults is 50% higher than for infants, but infant effective doses are four times higher than for adults. CT doses need to take into account patient age, head size, and composition as well as the selected x-ray technique factors

  8. When will Low-Contrast Features be Visible in a STEM X-Ray Spectrum Image?

    Science.gov (United States)

    Parish, Chad M

    2015-06-01

    When will a small or low-contrast feature, such as an embedded second-phase particle, be visible in a scanning transmission electron microscopy (STEM) X-ray map? This work illustrates a computationally inexpensive method to simulate X-ray maps and spectrum images (SIs), based upon the equations of X-ray generation and detection. To particularize the general procedure, an example of nanostructured ferritic alloy (NFA) containing nm-sized Y2Ti2O7 embedded precipitates in ferritic stainless steel matrix is chosen. The proposed model produces physically appearing simulated SI data sets, which can either be reduced to X-ray dot maps or analyzed via multivariate statistical analysis. Comparison to NFA X-ray maps acquired using three different STEM instruments match the generated simulations quite well, despite the large number of simplifying assumptions used. A figure of merit of electron dose multiplied by X-ray collection solid angle is proposed to compare feature detectability from one data set (simulated or experimental) to another. The proposed method can scope experiments that are feasible under specific analysis conditions on a given microscope. Future applications, such as spallation proton-neutron irradiations, core-shell nanoparticles, or dopants in polycrystalline photovoltaic solar cells, are proposed.

  9. Line x-ray source for diffraction enhanced imaging in clinical and industrial applications

    Science.gov (United States)

    Wang, Xiaoqin

    Mammography is one type of imaging modalities that uses a low-dose x-ray or other radiation sources for examination of breasts. It plays a central role in early detection of breast cancers. The material similarity of tumor-cell and health cell, breast implants surgery and other factors, make the breast cancers hard to visualize and detect. Diffraction enhanced imaging (DEI), first proposed and investigated by D. Chapman is a new x-ray radiographic imaging modality using monochromatic x-rays from a synchrotron source, which produced images of thick absorbing objects that are almost completely free of scatter. It shows dramatically improved contrast over standard imaging when applied to the same phantom. The contrast is based not only on attenuation but also on the refraction and diffraction properties of the sample. This imaging method may improve image quality of mammography, other medical applications, industrial radiography for non-destructive testing and x-ray computed tomography. However, the size, and cost, of a synchrotron source limits the application of the new modality to be applicable at clinical levels. This research investigates the feasibility of a designed line x-ray source to produce intensity compatible to synchrotron sources. It is composed of a 2-cm in length tungsten filament, installed on a carbon steel filament cup (backing plate), as the cathode and a stationary oxygen-free copper anode with molybdenum coating on the front surface serves as the target. Characteristic properties of the line x-ray source were computationally studied and the prototype was experimentally investigated. SIMIION code was used to computationally study the electron trajectories emanating from the filament towards the molybdenum target. A Faraday cup on the prototype device, proof-of-principle, was used to measure the distribution of electrons on the target, which compares favorably to computational results. The intensities of characteristic x-ray for molybdenum

  10. Effects of tube potential and scatter rejection on image quality and effective dose in digital chest X-ray examination: An anthropomorphic phantom study

    International Nuclear Information System (INIS)

    Shaw, D.J.; Crawshaw, I.; Rimmer, S.D.

    2013-01-01

    Objectives: The purpose of this study was to investigate the effects of tube potential and scatter rejection techniques on image quality of digital posteroanterior (PA) chest radiographs. Methods: An anthropomorphic phantom was imaged using a range of tube potentials (81–125 kV p ) without scatter rejection, with an anti-scatter grid, and using a 10 cm air gap. Images were anonymised and randomised before being evaluated using a visual graded analysis (VGA) method. Results: The effects of tube potential on image quality were found to be negligible (p > 0.63) for the flat panel detector (FPD). Decreased image quality (p = 0.031) was noted for 125 kV p relative to 109 kV p , though no difference was noted for any of the other potentials (p > 0.398) for computed radiography (CR). Both scatter rejection techniques improved image quality (p p . Scatter rejection improved image quality, but with no difference found between techniques. The air-gap resulted in a smaller increase in effective dose than the anti-scatter grid and would be the preferred scatter rejection technique

  11. Assessment of image quality in x-ray radiography imaging using a small plasma focus device

    Science.gov (United States)

    Kanani, A.; Shirani, B.; Jabbari, I.; Mokhtari, J.

    2014-08-01

    This paper offers a comprehensive investigation of image quality parameters for a small plasma focus as a pulsed hard x-ray source for radiography applications. A set of images were captured from some metal objects and electronic circuits using a low energy plasma focus at different voltages of capacitor bank and different pressures of argon gas. The x-ray source focal spot of this device was obtained to be about 0.6 mm using the penumbra imaging method. The image quality was studied by several parameters such as image contrast, line spread function (LSF) and modulation transfer function (MTF). Results showed that the contrast changes by variations in gas pressure. The best contrast was obtained at a pressure of 0.5 mbar and 3.75 kJ stored energy. The results of x-ray dose from the device showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. The measurements of LSF and MTF parameters were carried out by means of a thin stainless steel wire 0.8 mm in diameter and the cut-off frequency was obtained to be about 1.5 cycles/mm.

  12. Computer assisted analysis of medical x-ray images

    Science.gov (United States)

    Bengtsson, Ewert

    1996-01-01

    X-rays were originally used to expose film. The early computers did not have enough capacity to handle images with useful resolution. The rapid development of computer technology over the last few decades has, however, led to the introduction of computers into radiology. In this overview paper, the various possible roles of computers in radiology are examined. The state of the art is briefly presented, and some predictions about the future are made.

  13. A Soft X-ray Imager for MIRAX

    International Nuclear Information System (INIS)

    Zand, Jean in 't; Mels, Wim; Heise, John

    2006-01-01

    The flight spare model of the BeppoSAX Wide Field Cameras is being considered as the Soft X-ray Imager for MIRAX. A description is provided of this instrument, the performance of its siblings on BeppoSAX, and the prospects of flying it on MIRAX. Like on BeppoSAX, the instrument on MIRAX will excel in the study of transient phenomena lasting shorter than 1 day

  14. Comparison of the dose surface product in patients with X-ray contrast examinations of the stomach with intermittent and continuous radiographic methods

    International Nuclear Information System (INIS)

    Porzel, C.

    1975-01-01

    After commenting on the proplems of radiation exposure during X-raying and a brief survey of the development of image storage systems, the author explains the pulsed storage system used for X-raying the stomach instead of conventional X-raying. Applying the intermittent X-raying method, the exposure dose could be reduced by 75%, especially in patients with a strong abdominal girth. Advantages and disadvantages and possible ways to use the method for angiography, angiocardiography and X-raying in connection with bone operations are discussed. (ORU) [de

  15. Cytogenetics dosimetry: dose-response curve for low doses of X-ray

    International Nuclear Information System (INIS)

    Lara, Virginia E. Noval; Pineda Bolivar, William R.; Riano, Victor M. Pabon; Ureana, Cecilia Crane

    2013-01-01

    The purpose of this study was to conduct a preliminary study for the standardization in the future, the dose-response curve for low doses of X-rays, through the analysis of in vitro cultures of peripheral blood samples of 3 men and 3 women occupationally not exposed to artificial sources of ionizing radiation, age 18-40 years, where possible nonsmokers

  16. NASA Unveils First Images From Chandra X-Ray Observatory

    Science.gov (United States)

    1999-08-01

    Extraordinary first images from NASA's Chandra X-ray Observatory trace the aftermath of a gigantic stellar explosion in such stunning detail that scientists can see evidence of what may be a neutron star or black hole near the center. Another image shows a powerful X-ray jet blasting 200,000 light years into intergalactic space from a distant quasar. Released today, both images confirm that NASA's newest Great Observatory is in excellent health and its instruments and optics are performing up to expectations. Chandra, the world's largest and most sensitive X-ray telescope, is still in its orbital check-out and calibration phase. "When I saw the first image, I knew that the dream had been realized," said Dr. Martin Weisskopf, Chandra Project Scientist, NASA's Marshall Space Flight Center, Huntsville, AL. "This observatory is ready to take its place in the history of spectacular scientific achievements." "We were astounded by these images," said Harvey Tananbaum, Director of the Smithsonian Astrophysical Observatory's Chandra X- ray Center, Cambridge, MA. "We see the collision of the debris from the exploded star with the matter around it, we see shock waves rushing into interstellar space at millions of miles per hour, and, as a real bonus, we see for the first time a tantalizing bright point near the center of the remnant that could possibly be a collapsed star associated with the outburst." Chandra's PKS 0637-752 PKS 0637-752 After the telescope's sunshade door was opened last week, one of the first images taken was of the 320-year-old supernova remnant Cassiopeia A, which astronomers believe was produced by the explosion of a massive star. Material blasted into space from the explosion crashed into surrounding material at 10 million miles per hour. This collision caused violent shock waves, like massive sonic booms, creating a vast 50-million degree bubble of X-ray emitting gas. Heavy elements in the hot gas produce X-rays of specific energies. Chandra's ability

  17. Design of a normal incidence multilayer imaging X-ray microscope

    Science.gov (United States)

    Shealy, David L.; Gabardi, David R.; Hoover, Richard B.; Walker, Arthur B. C., Jr.; Lindblom, Joakim F.

    Normal incidence multilayer Cassegrain X-ray telescopes were flown on the Stanford/MSFC Rocket X-ray Spectroheliograph. These instruments produced high spatial resolution images of the sun and conclusively demonstrated that doubly reflecting multilayer X-ray optical systems are feasible. The images indicated that aplanatic imaging soft X-ray/EUV microscopes should be achievable using multilayer optics technology. A doubly reflecting normal incidence multilayer imaging X-ray microscope based on the Schwarzschild configuration has been designed. The design of the microscope and the results of the optical system ray trace analysis are discussed. High resolution aplanatic imaging X-ray microscopes using normal incidence multilayer X-ray mirrors should have many important applications in advanced X-ray astronomical instrumentation, X-ray lithography, biological, biomedical, metallurgical, and laser fusion research.

  18. Regularity of wound healing in rats irradiated locally with different doses of soft X-rays

    International Nuclear Information System (INIS)

    Liu Jianzhong; Zhou Yuanguo; Cheng Tianmin; Zhou Ping; Liu Xia; Li Ping

    2002-01-01

    Objective: To study the regular patter of wound healing in rats irradiated locally with different doses of soft X-rays. Methods: Rats were locally irradiated, and wounded immediately thereafter. Gross observation, histopathology and immunohistochemistry examinations, and image analysis were used to study the wound healing process. Results: The authors found that the delayed time of wound healing induced by soft X-ray irradiation of 0.50, 1.01, 1.96, 3,26, 4.00, 5.21 Gy was 1.6, 4.2, 5.4, 6.6, 8.2 and 9.4 days, respectively. Irradiation with 7.0 and 10.0 Gy caused failure of wound healing (up to 40 days). Compared to the non-irradiated wounds, the healing rates of irradiation-impaired wounds were lower during the whole healing process. From day 3 to day 9 after irradiation, the healing rates decreased along with increasing of the radiation dose, indicating the key phase of wound healing was delayed. After irradiation, the collagen synthesis was decreased, its arrangement was disordered, and the structure of granulation tissue was irregular. Conclusion: Soft X-rays irradiation may cause a delay of wound healing in a dose-dependent manner, and irradiation with 7.0 and 10.0 Gy cause failure of wound healing

  19. Cosolvent-free polymer gel dosimeters with improved dose sensitivity and resolution for x-ray CT dose response

    Energy Technology Data Exchange (ETDEWEB)

    Chain, J N M; McAuley, K B [Department of Chemical Engineering, Queen' s University, Kingston, K7L 3N6 (Canada); Jirasek, A [Department of Physics and Astronomy, University of Victoria, Victoria, V8W 3P6 (Canada); Schreiner, L J, E-mail: kim.mcauley@chee.queensu.ca [Cancer Centre of Southeastern Ontario, Kingston, K7L 5P9 (Canada)

    2011-04-07

    This study reports new N-isopropylacrylamide (NIPAM) polymer gel recipes with increased dose sensitivity and improved dose resolution for x-ray CT readout. NIPAM can be used to increase the solubility of N, N'-methylenebisacrylamide (Bis) in aqueous solutions from approximately 3% to 5.5% by weight, enabling the manufacture of dosimeters containing up to 19.5%T, which is the total concentration of NIPAM and Bis by weight. Gelatin is shown to have a mild influence on dose sensitivity when gels are imaged using x-ray CT, and a stronger influence when gels are imaged optically. Phantoms that contain only 3% gelatin and 5 mM tetrakis hydroxymethyl phosphonium chloride are sufficiently stiff for dosimetry applications. The best cosolvent-free gel formulation has a dose sensitivity in the linear range ({approx}0.88 H Gy{sup -1}) that is a small improvement compared to the best NIPAM-based gels that incorporate isopropanol as a cosolvent ({approx}0.80 H Gy{sup -1}). This new gel formulation results in enhanced dose resolution ({approx}0.052 Gy) for x-ray CT readout, making clinical applications of this imaging modality more feasible.

  20. Cosolvent-free polymer gel dosimeters with improved dose sensitivity and resolution for x-ray CT dose response

    International Nuclear Information System (INIS)

    Chain, J N M; McAuley, K B; Jirasek, A; Schreiner, L J

    2011-01-01

    This study reports new N-isopropylacrylamide (NIPAM) polymer gel recipes with increased dose sensitivity and improved dose resolution for x-ray CT readout. NIPAM can be used to increase the solubility of N, N'-methylenebisacrylamide (Bis) in aqueous solutions from approximately 3% to 5.5% by weight, enabling the manufacture of dosimeters containing up to 19.5%T, which is the total concentration of NIPAM and Bis by weight. Gelatin is shown to have a mild influence on dose sensitivity when gels are imaged using x-ray CT, and a stronger influence when gels are imaged optically. Phantoms that contain only 3% gelatin and 5 mM tetrakis hydroxymethyl phosphonium chloride are sufficiently stiff for dosimetry applications. The best cosolvent-free gel formulation has a dose sensitivity in the linear range (∼0.88 H Gy -1 ) that is a small improvement compared to the best NIPAM-based gels that incorporate isopropanol as a cosolvent (∼0.80 H Gy -1 ). This new gel formulation results in enhanced dose resolution (∼0.052 Gy) for x-ray CT readout, making clinical applications of this imaging modality more feasible.

  1. Evaluation of X ray attenuation by means of radiographic images

    International Nuclear Information System (INIS)

    Barros, Frieda Saicla; Paredes, Ramon S.C.; Godoi, Walmor C.; Souza, Gabriel Pinto de

    2011-01-01

    This paper's main goal is to adopt a qualitative methodology to evaluate the attenuation of x-radiation through X-ray images in polymeric materials plus residual lead. To determinate the images it was initially used an experimental setup at the Laboratory for Materials Diagnostics LACTEC. These results correspond to a more qualitative analysis, even with quantitative answers. Through analysis of radiographic images we can measure the intensity of radiation that goes through the plate, making possible to establish a relationship between the attenuation coefficient and the thickness of the material. (author)

  2. Physics-based optimization of image quality in 3D X-ray flat-panel cone-beam imaging

    NARCIS (Netherlands)

    Snoeren, R.M.

    2012-01-01

    This thesis describes the techniques for modeling and control of 3D X-ray cardiovascular systems in terms of Image Quality and patient dose, aiming at optimizing the diagnostic quality. When aiming at maximum Image Quality (IQ), a cascaded system constituted from inter-dependent imaging components,

  3. IXPE - The Imaging X-Ray Polarimetry Explorer

    Science.gov (United States)

    Ramsey, Brian

    2014-01-01

    The Imaging X-ray Polarimetry Explorer (IXPE) is a Small Explorer Mission that will be proposed in response to NASA's upcoming Announcement of Opportunity. IXPE will transform our understanding of the most energetic and exotic astrophysical objects, especially neutron stars and black holes, by measuring the linear polarization of astronomical objects as a function of energy, time and, where relevant, position. As the first dedicated polarimetry observatory IXPE will add a new dimension to the study of cosmic sources, enlarging the observational phase space and providing answers to fundamental questions. IXPE will feature x-ray optics fabricated at NASA/MSFC and gas pixel focal plane detectors provided by team members in Italy (INAF and INFN). This presentation will give an overview of the proposed IXPE mission, detailing the payload configuration, the expected sensitivity, and a typical observing program.

  4. Dose fractionation in synchrotron radiation x-ray phase micro-tomography

    International Nuclear Information System (INIS)

    Frachon, Thibaut; Weber, Loriane; Hesse, Bernhard; Rit, Simon; Dong, Pei; Olivier, Cecile; Peyrin, Françoise; Langer, Max

    2015-01-01

    Phase sensitive x-ray imaging expands the applicability of standard attenuation based techniques by offering several orders of magnitude of increase in sensitivity. Due to the short wavelength, x-ray phase is not directly measurable, but has to be put in evidence by the use of phase contrast techniques. The phase can then be reconstructed from one or several phase contrast images. In this study, we consider synchrotron x-ray phase micro-computed tomography (μCT) based on free space propagation for heterogeneous and strongly absorbing objects. This technique generally relies on acquiring several scans of the sample at different detector distances. It is also generally believed that multi-distance phase μCT needs a higher dose input than single distance phase μCT. The purpose of this work is to study the impact of different means of dose fractionation on the reconstructed image quality. We define different acquistion schemes in multi-distance in-line phase μCT. Previously, the exposure time at each sample-to-detector distance was usually kept the same. Here, we let not only the number of distances vary but also the fraction of exposure time at each distance, the total exposure time being kept constant. Phase retrieval is performed with the mixed approach algorithm. The reconstructed μCT images are compared in terms of accuracy, precision and resolution. In addition, we also compare the result of dose fractionated multi distance phase μCT to single distance phase μCT using the same total radiation dose. In the multi-distance approach, we find that using different exposure times on each distance improves the image quality in the reconstructed image. Further, we show that, despite having the same total dose delivery, the multi distance imaging method gives better image quality than the single distance method, at the cost of an additional overhead from camera displacements and reference images. We show that by optimizing the acquistion parameters in terms of

  5. Method of making tomographic images of X-rayed objects

    International Nuclear Information System (INIS)

    Eickel, R.

    1979-01-01

    A tomographic image of a selected layer of a stationary object is made by moving the source of X-rays along a first path at one side of the selected layer and by moving an ionography imaging chamber which contains a dielectric receptor sheet along a second path at the other side of the selected layer. The movement of the sheet is synchronized with movement of the source of X-rays and includes a translatory movement in a direction counter to the direction of movement of the source, a pivotal movement to maintain the sheet in a plane which is normal to the central beam of the bundle of X-rays, and a sidewise movement to vary the distance between the selected layer and the sheet so that the length of the projection of selected layer upon the sheet remains unchanged. If the sheet is rectangular, the pivotal movement is performed about an axis which is located in the plane of the selected layer and is parallel to the shorter sides of the sheet

  6. Problems with film processing in medical X-ray imaging in Lithuania

    International Nuclear Information System (INIS)

    Sniureviciute, M.; Adliene, D.

    2005-01-01

    Optimisation in X-ray imaging in order to reduce patient doses during diagnostic X-ray examinations is a complex process given the high level of image quality required. When quality systems are implemented as a basis for optimisation, attention should be paid to the qualifications of the staff and quality control of the equipment and of the X-ray imaging procedures, as well as to the methods used to evaluate the quality of these procedures. Until recently, quality control procedures at health care institutions in Lithuania were limited to the testing of X-ray units. Since film processing is one of the most important factors influencing patient doses and image quality during X-ray examinations, in 2003 the Kaunas department of the Radiation Protection Centre organised inspections of film processing laboratories in 11 health care institutions - hospitals and outpatient departments - in the Kaunas region. Problems of non-compliance with requirements identified during these inspections are discussed in this paper. Most of the health care institutions inspected already had quality assurance programmes. However, the implementation of these programmes was sometimes erratic because of the insufficient attention paid to the film developing processes. The worst situation was found in 4 institutions where the films were developed manually. Only 3 of the 11 departments inspected had sensitometers and densitometers for quality control of the processing. In many cases there was no control of chemicals, film sensitivity and density, or else control was irregular. In only a few departments were the effects of repeated controls investigated and discussed. Despite the current problems occurring in medical X-ray diagnostic departments in Lithuania, the situation is rapidly improving. New equipment is being installed, new devices for quality control are being used and, last but not least, the view of hospital administrators, radiologists and laboratory workers towards quality

  7. Generation of low KV x-ray portal images with mega-voltage electron beams

    International Nuclear Information System (INIS)

    Kenny, J.; Ebert, M.

    2004-01-01

    Full text: The increasing complexity of radiation therapy plans and reduced target margins, have made accurate localization of patients at treatment a crucial quality assurance issue. Mega-voltage portal images, the standard for treatment localization, are inherently low in contrast because x-ray attenuation at these energies is similar for most body tissues. Thus anatomical features are difficult to distinguish and match to features on a reference diagnostic image. This project investigates the possibly of using x-rays created by an external target placed in the path of a clinical mega-voltage electron beam. This target is optimised to produce a higher proportion of useful imaging x-rays in the range of 50-200kV. It is thought that a high efficiency Varian aSi500 amorphous silicon EPID will be sufficient to compensate for the very low efficiency of x-ray production. The project was undertaken with concurrent theoretical and experimental components. The former involved Monte Carlo models of low Z target design while in the later, experimental data was gathered to validate the model and explore the practical issues associated with electron mode image acquisition. A 6 MeV electron beam model for a Varian Clinac 21EX was developed with EGS4/BEAMnrc User Code and compared to measured beam data. Phase space data scored at the secondary collimator then became the input for simulations of a target placed in the accessory tray. Target materials were predominately low atomic number (Z) because a) production of high energy x-rays is minimized and, b) fewer low energy x-rays produced will be absorbed within the target. Photon and electron energy spectrums of the modified beam were evaluated for a range of target geometries. Ultimately, several materials were used in combination to optimise an x-ray yield for energies <200kV while removing electrons and very low energy x-rays, that contribute to patient dose but not to image formation. Low energy images of a PIPs EPID QA

  8. Assessment of organ equivalent doses and effective doses from diagnostic X-ray examinations

    International Nuclear Information System (INIS)

    Park, Sang Hyun

    2003-02-01

    The MIRD-type adult male, female and age 10 phantoms were constructed to evaluate organ equivalent dose and effective dose of patient due to typical diagnostic X-ray examination. These phantoms were constructed with external and internal dimensions of Korean. The X-ray energy spectra were generated with SPEC78. MCNP4B ,the general-purposed Monte Carlo code, was used. Information of chest PA , chest LAT, and abdomen AP diagnostic X-ray procedures was collected on the protocol of domestic hospitals. The results showed that patients pick up approximate 0.02 to 0.18 mSv of effective dose from a single chest PA examination, and 0.01 to 0.19 mSv from a chest LAT examination depending on the ages. From an abdomen AP examination, patients pick up 0.17 to 1.40 mSv of effective dose. Exposure time, organ depth from the entrance surface and X-ray beam field coverage considerably affect the resulting doses. Deviation among medical institutions is somewhat high, and this indicated that medical institutions should interchange their information and the need of education for medical staff. The methodology and the established system can be applied, with some expansion, to dose assessment for other medical procedures accompanying radiation exposure of patients like nuclear medicine or therapeutic radiology

  9. TU-G-207-00: Emerging Applications of X-Ray Imaging

    International Nuclear Information System (INIS)

    2015-01-01

    Last few years has witnessed the development of novel of X-ray imaging modalities, such as spectral CT, phase contrast CT, and X-ray acoustic/fluorescence/luminescence imaging. This symposium will present the recent advances of these emerging X-ray imaging modalities and update the attendees with knowledge in various related topics, including X-ray photon-counting detectors, X-ray physics underlying the emerging applications beyond the traditional X-ray imaging, image reconstruction for the novel modalities, characterization and evaluation of the systems, and their practical implications. In addition, the concept and practical aspects of X-ray activatable targeted nanoparticles for molecular X-ray imaging will be discussed in the context of X-ray fluorescence and luminescence CT. Learning Objectives: Present background knowledge of various emerging X-ray imaging techniques, such as spectral CT, phase contrast CT and X-ray fluorescence/luminescence CT. Discuss the practical need, technical aspects and current status of the emerging X-ray imaging modalities. Describe utility and future impact of the new generation of X-ray imaging applications

  10. Real time 2 dimensional detector for charged particle and soft X-ray images

    International Nuclear Information System (INIS)

    Ishikawa, M.; Ito, M.; Endo, T.; Oba, K.

    1995-01-01

    The conventional instruments used in experiments for the soft X-ray region such as X-ray diffraction analysis are X-ray films or imaging plates. However, these instruments are not suitable for real time observation. In this paper, newly developed imaging devices will be presented, which have the capability to take X-ray images in real time with a high detection efficiency. Also, another capability, to take elementary particle tracking images, is described. (orig.)

  11. Equally sloped X-ray microtomography of living insects with low radiation dose and improved resolution capability

    International Nuclear Information System (INIS)

    Yao, Shengkun; Fan, Jiadong; Zong, Yunbing; Sun, Zhibin; Zhang, Jianhua; Jiang, Huaidong; He, You; Zhou, Guangzhao; Xiao, Tiqiao; Huang, Qingjie

    2016-01-01

    Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique over conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ∼1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.

  12. Equally sloped X-ray microtomography of living insects with low radiation dose and improved resolution capability

    Science.gov (United States)

    Yao, Shengkun; Fan, Jiadong; Zong, Yunbing; He, You; Zhou, Guangzhao; Sun, Zhibin; Zhang, Jianhua; Huang, Qingjie; Xiao, Tiqiao; Jiang, Huaidong

    2016-03-01

    Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique over conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ˜1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.

  13. Equally sloped X-ray microtomography of living insects with low radiation dose and improved resolution capability

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Shengkun; Fan, Jiadong; Zong, Yunbing; Sun, Zhibin; Zhang, Jianhua; Jiang, Huaidong, E-mail: hdjiang@sdu.edu.cn [State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); He, You; Zhou, Guangzhao; Xiao, Tiqiao [Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Huang, Qingjie [School of Information Science and Engineering, Shandong University, Jinan 250100 (China)

    2016-03-21

    Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique over conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ∼1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.

  14. X-ray image intensifier camera tubes and semiconductor targets

    International Nuclear Information System (INIS)

    1979-01-01

    A semiconductor target for use in an image intensifier camera tube and a camera using the target are described. The semiconductor wafer for converting an electron image onto electrical signal consists mainly of a collector region, preferably n-type silicon. It has one side for receiving the electron image and an opposite side for storing charge carriers generated in the collector region by high energy electrons forming a charge image. The first side comprises a highly doped surface layer covered with a metal buffer layer permeable to the incident electrons and thick enough to dissipate some of the incident electron energy thereby improving the signal-to-noise ratio. This layer comprises beryllium on niobium on the highly doped silicon surface zone. Low energy Kα X-ray radiation is generated in the first layer, the radiation generated in the second layer (mainly Lα radiation) is strongly absorbed in the silicon layer. A camera tube using such a target with a photocathode for converting an X-ray image into an electron image, means to project this image onto the first side of the semiconductor wafer and means to read out the charge pattern on the second side are also described. (U.K.)

  15. Materials science with SR using x-ray imaging

    International Nuclear Information System (INIS)

    Kuriyama, Masao

    1990-01-01

    Some examples of applications of synchrotron radiation to materials science demonstrate the importance of microstructure information within structural as well as functional materials in order to control their properties and quality as designed for industrial purposes. To collect such information, x-ray imaging in quasi real time is required in either the microradiographic mode or the diffraction (in transmission) mode. New measurement technologies based on imaging are applied to polycrystalline materials, single crystal materials and multilayered device materials to illustrate what kind of synchrotron radiation facility is most desirable for materials science and engineering. (author)

  16. Imaging Macromolecules with X-ray laser pulses

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    The short wavelength of X-rays allows us to resolve atoms, but in practise for biological materials the achievable resolution is limited by the destruction of the sample by the radiation that forms the image.  For over 100 years, the workaround to this problem of radiation damage has been to average signals from repeating copies of the object arranged in a large crystal.  It is now possible to overcome damage limits by using intense X-ray pulses that vaporise the sample, but which are short enough in duration to freeze any motion of the sample on the atomic scale.  With the advent of X-ray FELs we have been able to confirm this principle, and are now applying it to overcoming a major bottleneck for protein crystallography, which is the need for large well-diffracting crystals.  The intense pulses also open up opportunities to help solve the crystallographic phase problem.  In particular we have found that commonly-occurring disordered crystals that are usually not ...

  17. Study of hard X-ray dose enhancement effects for some kinds of semiconductor devices

    CERN Document Server

    Guo Hong Xia; Chen Yu Sheng; Zhou Hui; He Chao Hui; Xie Ya Ning; Huang Yu Ying; He Wei; Hu Tian Dou

    2002-01-01

    Experimental results of X-ray dose enhancement effects are given for CMOS4069 and floating gate ROMs irradiated in Beijing Synchrotron Radiation Facility and in cobalt source. Shift of threshold voltage vs. total dose for CMOS4069 and the errors vs. total dose for 28f256 and 29c256 have been tested on line and the equivalent relation of total dose damage under the same accumulated dose is provided comparing the response of devices irradiated by X-ray and gamma-ray source. These results can be provided for X-ray radiation hardening technology as an effective evaluation data

  18. Scatter and transmission doses from several pediatric X-ray examinations in a nursery

    International Nuclear Information System (INIS)

    Burrage, John W.; Rampant, Peter L.; Beeson, Brendan P.

    2003-01-01

    While several studies have investigated the dose from scattered radiation from X-ray procedures in a pediatric nursery, they examined scatter from chest procedures only, or the types of examination were not specified. The aim of this study was to collect scatter and transmission data from several types of X-ray examinations. Using a ''newborn'' anthropomorphic phantom and an ion chamber, a series of scatter and transmission dose measurements were performed using typical exposure factors for chest, chest and abdomen, skull, skeletal long bone and spine procedures. The phantom was inside a crib for all exposures. The maximum scatter dose measured at 1 m from the field center was about 0.05 μGy per exposure for lateral skulls. Transmission doses for lateral exams were around 0.1 μGy per exposure at 1 m from the isocenter. The study demonstrated that scatter dose to other patients in a neonatal unit is not significant, assuming the distance between adjacent cribs is in the order of 1 m. Transmission doses are also low provided the beam is fully intercepted by the cassette. For an average workload the dose received by imaging technologists would be small. (orig.)

  19. Moving-Article X-Ray Imaging System and Method for 3-D Image Generation

    Science.gov (United States)

    Fernandez, Kenneth R. (Inventor)

    2012-01-01

    An x-ray imaging system and method for a moving article are provided for an article moved along a linear direction of travel while the article is exposed to non-overlapping x-ray beams. A plurality of parallel linear sensor arrays are disposed in the x-ray beams after they pass through the article. More specifically, a first half of the plurality are disposed in a first of the x-ray beams while a second half of the plurality are disposed in a second of the x-ray beams. Each of the parallel linear sensor arrays is oriented perpendicular to the linear direction of travel. Each of the parallel linear sensor arrays in the first half is matched to a corresponding one of the parallel linear sensor arrays in the second half in terms of an angular position in the first of the x-ray beams and the second of the x-ray beams, respectively.

  20. X-ray fluorescence holography and multiple-energy x-ray holography: A critical comparison of atomic images

    International Nuclear Information System (INIS)

    Len, P.M.; Gog, T.; Fadley, C.S.; Materlik, G.

    1997-01-01

    We compare x-ray fluorescence holography (XFH) and multiple-energy x-ray holography (MEXH), two techniques that have recently been used to obtain experimental three-dimensional atomic images. For single-energy holograms, these methods are equivalent by virtue of the optical reciprocity theorem. However, XFH can only record holographic information at the characteristic fluorescence energies of the emitting species, while MEXH can record holographic information at any energy above the fluorescent edge of the emitter, thus enabling the suppression of real-twin overlaps and other aberrations and artifacts in atomic images. copyright 1997 The American Physical Society

  1. Patient size and x-ray technique factors in head computed tomography examinations. II. Image quality

    International Nuclear Information System (INIS)

    Huda, Walter; Lieberman, Kristin A.; Chang, Jack; Roskopf, Marsha L.

    2004-01-01

    We investigated how patient head characteristics, as well as the choice of x-ray technique factors, affect lesion contrast and noise values in computed tomography (CT) images. Head sizes and mean Hounsfield unit (HU) values were obtained from head CT images for five classes of patients ranging from the newborn to adults. X-ray spectra with tube voltages ranging from 80 to 140 kV were used to compute the average photon energy, and energy fluence, transmitted through the heads of patients of varying size. Image contrast, and the corresponding contrast to noise ratios (CNRs), were determined for lesions of fat, muscle, and iodine relative to a uniform water background. Maintaining a constant image CNR for each lesion, the patient energy imparted was also computed to identify the x-ray tube voltage that minimized the radiation dose. For adults, increasing the tube voltage from 80 to 140 kV changed the iodine HU from 2.62x10 5 to 1.27x10 5 , the fat HU from -138 to -108, and the muscle HU from 37.1 to 33.0. Increasing the x-ray tube voltage from 80 to 140 kV increased the percentage energy fluence transmission by up to a factor of 2. For a fixed x-ray tube voltage, the percentage transmitted energy fluence in adults was more than a factor of 4 lower than for newborns. For adults, increasing the x-ray tube voltage from 80 to 140 kV improved the CNR for muscle lesions by 130%, for fat lesions by a factor of 2, and for iodine lesions by 25%. As the size of the patient increased from newborn to adults, lesion CNR was reduced by about a factor of 2. The mAs value can be reduced by 80% when scanning newborns while maintaining the same lesion CNR as for adults. Maintaining the CNR of an iodine lesion at a constant level, use of 140 kV increases the energy imparted to an adult patient by nearly a factor of 3.5 in comparison to 80 kV. For fat and muscle lesions, raising the x-ray tube voltage from 80 to 140 kV at a constant CNR increased the patient dose by 37% and 7

  2. X-ray or UV-ray imaging sensor utilizing optically stimulated luminescence phenomenon in Eu-doped KCl phosphors

    International Nuclear Information System (INIS)

    Nanto, Hidehito; Murayama, Kazuhiko; Hirai, Yoshiaki; Taniguchi, Shin-ichi; Makamura, Shouichi; Takeuchi, Nozomu.

    1993-01-01

    An intense OSL with a peak at about 420 [nm] has been observed by stimulating an X-ray or UV-ray irradiated KCl: Eu crystal with F-band light whose wavelength is about 560 [um]. A possible excitation and emission mechanisms for the 420 [um] OSL peak X-ray or UV-ray irradiated sample is proposed. It is found that the OSL intensity is proportional to the X-ray absorbed dose or UV-ray irradiation dose. It is also found that X-ray or UV-ray irradiated KCl; Eu exhibited excellent fading characteristics. These results strongly suggest that the KCl: Eu is one of the most attractive candidates for two-dimensional X-ray or UV-ray imaging sensor utilizing the OSL phenomenon. (J.P.N.)

  3. Image quality analysis of vibration effects In C-arm-flat panel X-ray imaging

    NARCIS (Netherlands)

    Snoeren, R.M.; Kroon, J.N.; With, de P.H.N.

    2011-01-01

    The motion of C-arm scanning X-ray systems may result in vibrations of the imaging sub-system. In this paper, we connect C-arm system vibrations to Image Quality (IQ) deterioration for 2D angiography and 3D cone beam X-ray imaging, using large Flat Panel detectors. Vibrations will affect the

  4. A highly sensitive x-ray imaging modality for hepatocellular carcinoma detection in vitro

    Science.gov (United States)

    Rand, Danielle; Walsh, Edward G.; Derdak, Zoltan; Wands, Jack R.; Rose-Petruck, Christoph

    2015-01-01

    Innovations that improve sensitivity and reduce cost are of paramount importance in diagnostic imaging. The novel x-ray imaging modality called spatial frequency heterodyne imaging (SFHI) is based on a linear arrangement of x-ray source, tissue, and x-ray detector, much like that of a conventional x-ray imaging apparatus. However, SFHI rests on a complete paradigm reversal compared to conventional x-ray absorption-based radiology: while scattered x-rays are carefully rejected in absorption-based x-ray radiology to enhance the image contrast, SFHI forms images exclusively from x-rays scattered by the tissue. In this study we use numerical processing to produce x-ray scatter images of hepatocellular carcinoma labeled with a nanoparticle contrast agent. We subsequently compare the sensitivity of SFHI in this application to that of both conventional x-ray imaging and magnetic resonance imaging (MRI). Although SFHI is still in the early stages of its development, our results show that the sensitivity of SFHI is an order of magnitude greater than that of absorption-based x-ray imaging and approximately equal to that of MRI. As x-ray imaging modalities typically have lower installation and service costs compared to MRI, SFHI could become a cost effective alternative to MRI, particularly in areas of the world with inadequate availability of MRI facilities.

  5. Detection of soft X-rays from α Lyrae and eta Bootis with an imaging X-ray telescope

    International Nuclear Information System (INIS)

    Topka, K.; Fabricant, D.; Harnden, F.R. Jr.; Gorenstein, P.; Rosner, R.

    1979-01-01

    Two nearby stars have been detected in the soft X-ray band with an imaging X-ray telescope flown aboard two sounding rockets. The exposure times were 4.8 and 4.5 s for the images of the AO V star α Lyrae (Vega) and the GO IV star eta Bootis, respectively. Laboratory measurements rule out the possibility that the observed signals were due to UV contamination. These X-ray observations imply luminosities of L/sub X/(0.2--0.8 keV) approx. =3 x 10 28 ergs s -1 for Vega and L/sub X/(0.15--1.5 keV) approx. =1 x 10 29 ergs s -1 for eta Boo. A coronal interpretation of the X-rays from Vega is in serious conflict with simple convective models for early-type main-sequence stars. Magnetic field activity may be responsible for heating the corona, as has been suggested for the Sun. In the case of eta Boo, a coronal interpretation is also favored; however, if the unseen companion of eta Boo is degenerate, the X-ray emission may instead originate in a stellar wind accreting upon a white dwarf or neutron star

  6. Trends and the determination of effective doses for standard X-ray procedures

    International Nuclear Information System (INIS)

    Johnson, H.M.; Neduzak, C.; Gallet, J.; Sandeman, J.

    2001-01-01

    Trends in the entrance skin exposures (air kerma) for standard x-ray imaging procedures are reported for the Province of Manitoba, Canada. Average annual data per procedure using standard phantoms and standard ion chambers have been recorded since 1981. For example, chest air kerma (backscatter included) has decreased from 0.14 to 0.09 mGy. Confounding factors may negate the gains unless facility quality control programs are maintained. The data were obtained for a quality assurance and regulatory compliance program. Quoting such data for risk evaluation purposes lacks rigor hence a compartment model for organ apportioning, using organ absorbed doses and weighting factors, has been applied to determine effective dose per procedure. The effective doses for the standard procedures are presented, including the value of 0.027 mSv (1999) calculated for the effective dose in PA chest imaging. (author)

  7. Measurement of X-ray for the dose area product and spectrum by the added filtration in Rando phantom

    Science.gov (United States)

    Lee, Jong-Woong; Kim, Eun-Soo; Choi, Jiwon; Kweon, Dae Cheol

    2014-02-01

    The most important point in the medical use of radiation is to minimize the patient entrance dose while maintaining the diagnostic information. Low-energy photons (long-wave X-ray) are unnecessary among diagnostic X-ray because they are mostly absorbed and increase the patient's entrance dose. The most effective method to eliminate the low-energy photon is use of a filtering plate. Using a filter appropriate for the image will maintain diagnostic value. Obtaining an effective image allows comparison of the resulting images in a logical objective way. This experiment was performed to determine the quality of image dosimeter when there is no filter, and when 2 mm Al, 0.1 mm Cu + 1 mm Al, 0.2 mm Cu + 1 mm Al filters are used. Using TORECK PD-8100 dose area products meter placed on top of an abdominal phantom, we measured the dose when the filter changes in this condition 85 kVp, 40 mAs, anode angle 13, source image distance 100 cm, 20 cm × 20 cm. We used the SRS-78 program for accurate comparison because we could not evaluate the difference in the image optically. The spectrum changed due to the emission of X-rays as the filter changed. We observed that the use of a filter eliminated the low-energy photons and revealed continuous X-ray and special X-ray. Therefore, the experiment highlighted the advantages of filters and confirmed that there are no changes in the quality of image through signal to noise ratio, peak signal to noise ratio, root mean square error comparison. We found that the use of filter did not lead to distortions in the image or drop in diagnostic value while minimizing the radiation dose. This means that it can help manage long-term patient dose. We conclude that we need to recommend the use of the filter as it reduces the area of dose.

  8. Patient dose simulation in X-ray CT using a radiation treatment-planning system

    International Nuclear Information System (INIS)

    Nakae, Yasuo; Oda, Masahiko; Minamoto, Takahiro

    2003-01-01

    Medical irradiation dosage has been increasing with the development of new radiological equipment and new techniques like interventional radiology. It is fair to say that patient dose has been increased as a result of the development of multi-slice CT. A number of studies on the irradiation dose of CT have been reported, and the computed tomography dose index (CTDI) is now used as a general means of determining CT dose. However, patient dose distribution in the body varies with the patient's constitution, bowel gas in the body, and conditions of exposure. In this study, patient dose was analyzed from the viewpoint of dose distribution, using a radiation treatment-planning computer. Percent depth dose (PDD) and the off-center ratio (OCR) of the CT beam are needed to calculate dose distribution by the planning computer. Therefore, X-ray CT data were measured with various apparatuses, and beam data were sent to the planning computer. Measurement and simulation doses in the elliptical phantom (Mix-Dp: water equivalent material) were collated, and the CT irradiation dose was determined for patient dose simulation. The rotational radiation treatment technique was used to obtain the patient dose distribution of CT, and patient dose was evaluated through simulation of the dose distribution. CT images of the thorax were sent to the planning computer and simulated. The result was that the patient dose distribution of the thorax was obtained for CT examination. (author)

  9. State of development and development trends of X-ray image intensifier television systems

    International Nuclear Information System (INIS)

    Pfeiler, M.; Haendle, J.

    1975-01-01

    Following a survey on the development of X-ray image intensifier television systems up to now, their further development is critically discussed with regard to the better image quality to be expected. The introduction of the high-resolving X-ray image intensifier already meant an improvement in image quality even though the television system remained the same. In the image intensifier television system, the distinguishability of small details suffers from noise effects. Therefore, a better image quality is especially advantageous in those ranges of application which allow a higher picture dose. 'Electronic' radiography, intermittent screening, co-storage of the spotfilm radiographs, videometry, video area kymography, and cardiac stroboscopy are examples some of which have already been tested in clinical practice. (orig./AK) [de

  10. Guidelines on best practice in the X-ray imaging of children. A manual for all X-ray departments

    International Nuclear Information System (INIS)

    Cook, J.; Pettett, A.; Shah, K.

    1998-01-01

    When we were first asked to participate in a CEC project looking at best practice in paediatric radiology, we did not appreciate how much our own practice could be improved. The department already had high standards of radiography. However, despite our initial reservations we found that by reassessing all our practices, including choice of screen/film systems, use of filters, grids and exposure factors we were able to standardise our techniques and reduce our doses in many areas by over 50%, while still maintaining diagnostic quality. The published European Guidelines on Quality Criteria for Diagnostic Radiographic Images in Paediatrics (1996) was our initiative. They provide a combination of positioning and visibility criteria. Radiographs which do not meet these criteria are not thought to be diagnostic and alternatively aesthetically high quality radiographs which exceed these criteria are not deemed necessary. The reference dose levels in the European Guidelines are those above which corrective action should be taken. The dose measurements in our guidelines are much lower and represent what is achievable with the available equipment at QMHC, while still meeting the European Quality Criteria. A new age of Digital radiography is replacing conventional radiography. However, as digital techniques can mask high doses, careful observation of quality criteria and recommended technique is even more important to obtain the most benefit from these technical advances. Despite the time consuming nature of the initial study the whole department has benefited and we encourage all those involved in the X-ray imaging of children to consider re-evaluating their own practices using these guidelines as a reference for comparison. We recognise that all the recommendations given are entirely dependent on the range of equipment available and pathology expected but can be modified to meet individual departmental needs. If practices/ techniques; diagnostic quality of radiographs or

  11. Experimental study on x-rays dose enhancement effects for floating gate ROMs

    CERN Document Server

    Guo Hong Xia; Chen Yu Sheng; Han Fu Bin; He Chao Hui; Zhao Hui

    2002-01-01

    Experimental results of x-ray dose enhancement effects are given for floating gate read-only memory (ROMs) irradiated in the Beijing Synchrotron Radiation Facility. The wrong byte numbers vs. total irradiation dose have been tested and the equivalent relation of total dose damage is provided compared the response of devices irradiated with sup 6 sup 0 Co gamma-ray source. The x-ray dose enhancement factors for floating gate ROMs are obtained firstly in China. These results can be an effective evaluation data for x-rays radiation hardening technology

  12. Effect Of Small Doses On THE Thymus In Pediatric Chest X - Ray

    International Nuclear Information System (INIS)

    Milkovic, Dj.; Ranogajec-Komor, M.; Anzic, S. A.; Zagar, I.

    2015-01-01

    The thymus, pyramid-shaped lymphoid organ is immediately beneath the breastbone at the level of the heart, therefore chest X-ray covers the position of thymus. The thymus is divided into two lobes, lying on either side of the midline of the body. Unlike most other lymphoid structures, the thymus grows rapidly and attains its greatest size relative to the rest of the body during fetal life and the first years after birth. The thymus is a specialized organ of the immune system. It has big responsibility helping the body protect itself against autoimmunity diseases. It is well known from literature data that thymus size reduced at radiotherapy irradiation. After many years of experience in X-ray chest diagnostics with children a fairly regular thymus size reduction after exposure to diagnostic low doses was noticed. Therefore it was analysed at what percentage of children patients their control radiograms would exhibit a thymus shade decrease compared to the primary image taken at the illness out-set. In the Children Hospital Srebrnjak in one year 1972 children in the age group 0 - 5 years underwent X-ray exam. In our earlier study at PA and profile projections of lung examinations of this age group 0.15 mSv and 0.11 mSv average doses were measured on the back and on the chest, respectively. From this group the radiograms of those 119 children were analysed who were exposed, according to medical indication, to control examinations. 58 of the investigated patients showed enlarged thymus at the first exam. It could be seen from the control radiogram that 52 children of these 58 patients had significant or discrete decrease in size of thymus. Taking into account that thymus has very important role in maturity of T-lymphocytes and development of immunology tolerance these empiric statements are important for radiation protection of children in X-ray diagnostic of chest. (author).

  13. Computed tomography of x-ray images using neural networks

    Science.gov (United States)

    Allred, Lloyd G.; Jones, Martin H.; Sheats, Matthew J.; Davis, Anthony W.

    2000-03-01

    Traditional CT reconstruction is done using the technique of Filtered Backprojection. While this technique is widely employed in industrial and medical applications, it is not generally understood that FB has a fundamental flaw. Gibbs phenomena states any Fourier reconstruction will produce errors in the vicinity of all discontinuities, and that the error will equal 28 percent of the discontinuity. A number of years back, one of the authors proposed a biological perception model whereby biological neural networks perceive 3D images from stereo vision. The perception model proports an internal hard-wired neural network which emulates the external physical process. A process is repeated whereby erroneous unknown internal values are used to generate an emulated signal with is compared to external sensed data, generating an error signal. Feedback from the error signal is then sued to update the erroneous internal values. The process is repeated until the error signal no longer decrease. It was soon realized that the same method could be used to obtain CT from x-rays without having to do Fourier transforms. Neural networks have the additional potential for handling non-linearities and missing data. The technique has been applied to some coral images, collected at the Los Alamos high-energy x-ray facility. The initial images show considerable promise, in some instances showing more detail than the FB images obtained from the same data. Although routine production using this new method would require a massively parallel computer, the method shows promise, especially where refined detail is required.

  14. High-resolution 3D X-ray imaging of intracranial nitinol stents

    International Nuclear Information System (INIS)

    Snoeren, Rudolph M.; With, Peter H.N. de; Soederman, Michael; Kroon, Johannes N.; Roijers, Ruben B.; Babic, Drazenko

    2012-01-01

    To assess an optimized 3D imaging protocol for intracranial nitinol stents in 3D C-arm flat detector imaging. For this purpose, an image quality simulation and an in vitro study was carried out. Nitinol stents of various brands were placed inside an anthropomorphic head phantom, using iodine contrast. Experiments with objects were preceded by image quality and dose simulations. We varied X-ray imaging parameters in a commercially interventional X-ray system to set 3D image quality in the contrast-noise-sharpness space. Beam quality was varied to evaluate contrast of the stents while keeping absorbed dose below recommended values. Two detector formats were used, paired with an appropriate pixel size and X-ray focus size. Zoomed reconstructions were carried out and snapshot images acquired. High contrast spatial resolution was assessed with a CT phantom. We found an optimal protocol for imaging intracranial nitinol stents. Contrast resolution was optimized for nickel-titanium-containing stents. A high spatial resolution larger than 2.1 lp/mm allows struts to be visualized. We obtained images of stents of various brands and a representative set of images is shown. Independent of the make, struts can be imaged with virtually continuous strokes. Measured absorbed doses are shown to be lower than 50 mGy Computed Tomography Dose Index (CTDI). By balancing the modulation transfer of the imaging components and tuning the high-contrast imaging capabilities, we have shown that thin nitinol stent wires can be reconstructed with high contrast-to-noise ratio and good detail, while keeping radiation doses within recommended values. Experimental results compare well with imaging simulations. (orig.)

  15. Low-dose x-ray phase-contrast and absorption CT using equally sloped tomography

    International Nuclear Information System (INIS)

    Fahimian, Benjamin P; Miao Jianwei; Mao Yu; Cloetens, Peter

    2010-01-01

    Tomographic reconstruction from undersampled and noisy projections is often desirable in transmission CT modalities for purposes of low-dose tomography and fast acquisition imaging. However under such conditions, due to the violation of the Nyquist sampling criteria and the presence of noise, reconstructions with acceptable accuracy may not be possible. Recent experiments in transmission electron tomography and coherent diffraction microscopy have shown that the technique of equally sloped tomography (EST), an exact tomographic method utilizing an oversampling iterative Fourier-based reconstruction, provides more accurate image reconstructions when the number of projections is significantly undersampled relative to filtered back projection and algebraic iterative methods. Here we extend this technique by developing new reconstruction algorithms which allow for the incorporation of advanced mathematical regularization constraints, such as the nonlocal means total variational model, in a manner that is consistent with experimental projections. We then evaluate the resulting image quality of the developed algorithm through simulations and experiments at the European Synchrotron Radiation Facility on image quality phantoms using the x-ray absorption and phase contrast CT modalities. Both our simulation and experimental results have indicated that the method can reduce the number of projections by 60-75% in parallel beam modalities, while achieving comparable or better image quality than the conventional reconstructions. As large-scale and compact synchrotron radiation facilities are currently under rapid development worldwide, the implementation of low-dose x-ray absorption and phase-contrast CT can find broad applications in biology and medicine using these advanced x-ray sources.

  16. The pin pixel detector--X-ray imaging

    CERN Document Server

    Bateman, J E; Derbyshire, G E; Duxbury, D M; Marsh, A S; Simmons, J E; Stephenson, R

    2002-01-01

    The development and testing of a soft X-ray gas pixel detector, which uses connector pins for the anodes is reported. Based on a commercial 100 pin connector block, a prototype detector of aperture 25.4 mm centre dot 25.4 mm can be economically fabricated. The individual pin anodes all show the expected characteristics of small gas detectors capable of counting rates reaching 1 MHz per pin. A 2-dimensional resistive divide readout system has been developed to permit the imaging properties of the detector to be explored in advance of true pixel readout electronics.

  17. Improved fluorescent X-ray image intensifying screen

    International Nuclear Information System (INIS)

    Landeghem, W.K. van; Suys, A.R.

    1981-01-01

    An X-ray image intensifying screen is described, which includes at least one fluorescent layer comprising phosphor particles dispersed in a binder and on top of such layer a protective layer containing a crosslinked polymer mass obtained by an acid-catalyzed reaction of a polymer or mixture of polymers containing reactive hydrogen atoms and a cross-linking agent, the cross-linking agent being an organic compound containing a plurality of etherified N-methylol groups. Examples are given of appropriate polymers and cross-linking agents. (author)

  18. Design considerations for soft X-ray television imaging detectors

    International Nuclear Information System (INIS)

    Kalata, K.; Golub, L.

    1988-01-01

    Television sensors for X-rays can be coupled to converters and image intensifiers to obtain active areas, high flux capabilities, quantum efficiency, high time resolution, or ease of construction and operation that may not be obtained with a directly illuminated sensor. A general purpose system which makes use of these capabilities for a number of applications is decribed. Some of the performance characteristics of this type of system are examined, and the expected future developments for such systems are briefly addressed. 19 refs

  19. Multiframe digitization of x-ray (TV) images (abstract)

    Science.gov (United States)

    Karpenko, V. A.; Khil'chenko, A. D.; Lysenko, A. P.; Panchenko, V. E.

    1989-07-01

    The work in progress deals with the experimental search for a technique of digitizing x-ray TV images. The small volume of the buffer memory of the analog-to-digital (A/D) converter (ADC) we have previously used to detect TV signals made it necessary to digitize only one line at a time of the television raster and also to make use of gating to gain the video information contained in the whole frame. This paper is devoted to multiframe digitizing. The recorder of video signals comprises a broadband 8-bit A/D converter, a buffer memory having 128K words and a control circuit which forms a necessary sequence of advance pulses for the A/D converter and the memory relative to the input frame and line sync pulses (FSP and LSP). The device provides recording of video signals corresponding to one or a few frames following one after another, or to their fragments. The control circuit is responsible for the separation of the required fragment of the TV image. When loading the limit registers, the following input parameters of the control circuit are set: the skipping of a definite number of lines after the next FSP, the number of the lines of recording inside a fragment, the frequency of the information lines inside a fragment, the delay in the start of the ADC conversion relative to the arrival of the LSP, the length of the information section of a line, and the frequency of taking the readouts in a line. In addition, among the instructions given are the number of frames of recording and the frequency of their sequence. Thus, the A/D converter operates only inside a given fragment of the TV image. The information is introduced into the memory in sequence, fragment by fragment, without skipping and is then extracted as samples according to the addresses needed for representation in the required form, and processing. The video signal recorder governs the shortest time of the ADC conversion per point of 250 ns. As before, among the apparatus used were an image vidicon with

  20. Structure determination of spider silk from X-ray images

    Energy Technology Data Exchange (ETDEWEB)

    Ulrich, Stephan; Zippelius, Annette [Universitaet Goettingen, Institut fuer Theoretische Physik (Germany); Meling, Martin [Max-Planck-Institut fuer biophysikalische Chemie, Goettingen (Germany); Glisovic, Anja; Salditt, Tim [Universitaet Goettingen, Institut fuer Roentgenphysik (Germany)

    2008-07-01

    Spider silk consists of interconnected crystallites, which are typically aligned along the fiber axis. We present a method to systematically determine the structure of these crystallites. Hereby we introduce a model that calculates the scattering function G(q) which is fitted to the measured X-ray image (silk from nephila clavipes). With it, the crystallites' size, the constitution and dimensions of their unit cell, as well as their tilt with respect to the fiber axis is identified, and furthermore the effect of coherent scattering from different crystallites is investigated. The shown methods and the presented model can easily be generalized to a wide class of composite materials.

  1. Principles of image reconstruction in X-ray computer tomography

    International Nuclear Information System (INIS)

    Schwierz, G.; Haerer, W.; Ruehrnschopf, E.P.

    1978-01-01

    The presented geometrical interpretation elucidates the convergence behavior of the classical iteration technique in X-ray computer tomography. The filter techniques nowadays used in preference are derived from a concept of linear system theory which excels due to its particular clarity. The one-dimensional form of the filtering is of decisive importance for immediate image reproduction as realized by both Siemens systems, the SIRETOM 2000 head scanner and the SOMATOM whole-body machine, as such unique to date for whole-body machines. The equivalence of discrete and continuous filtering when dealing with frequency-band-limited projections is proved. (orig.) [de

  2. Three-dimensional phase-contrast X-ray microtomography with scanning–imaging X-ray microscope optics

    International Nuclear Information System (INIS)

    Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio

    2013-01-01

    A novel three-dimensional X-ray microtomographic micro-imaging system which enables simultaneous measurement of differential phase contrast and absorption contrast has been developed. The optical system consists of a scanning microscope with one-dimensional focusing device and an imaging microscope with one-dimensional objective. A three-dimensional (3D) X-ray tomographic micro-imaging system has been developed. The optical system is based on a scanning–imaging X-ray microscope (SIXM) optics, which is a hybrid system consisting of a scanning microscope optics with a one-dimensional (1D) focusing (line-focusing) device and an imaging microscope optics with a 1D objective. In the SIXM system, each 1D dataset of a two-dimensional (2D) image is recorded independently. An object is illuminated with a line-focused beam. Positional information of the region illuminated by the line-focused beam is recorded with the 1D imaging microscope optics as line-profile data. By scanning the object with the line focus, 2D image data are obtained. In the same manner as for a scanning microscope optics with a multi-pixel detector, imaging modes such as phase contrast and absorption contrast can be arbitrarily configured after the image data acquisition. By combining a tomographic scan method and the SIXM system, quantitative 3D imaging is performed. Results of a feasibility study of the SIXM for 3D imaging are shown

  3. Fast Fiber-Coupled Imaging of X-rays Events, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — HyperV Technologies Corp. proposes to construct a long-record-length, fiber-coupled, fast imaging diagnostic for recording X-ray back-lit material flows and X-ray...

  4. 21 CFR 892.1650 - Image-intensified fluoroscopic x-ray system.

    Science.gov (United States)

    2010-04-01

    ... fluoroscopic x-ray system. (a) Identification. An image-intensified fluoroscopic x-ray system is a device... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Image-intensified fluoroscopic x-ray system. 892... equipment, patient and equipment supports, component parts, and accessories. (b) Classification. Class II...

  5. 21 CFR 892.1660 - Non-image-intensified fluoroscopic x-ray system.

    Science.gov (United States)

    2010-04-01

    ... fluoroscopic x-ray system. (a) Identification. A non-image-intensified fluoroscopic x-ray system is a device... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Non-image-intensified fluoroscopic x-ray system... display equipment, patient and equipment supports, component parts, and accessories. (b) Classification...

  6. Skull x-ray

    Science.gov (United States)

    X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  7. Neck x-ray

    Science.gov (United States)

    X-ray - neck; Cervical spine x-ray; Lateral neck x-ray ... There is low radiation exposure. X-rays are monitored so that the lowest amount of radiation is used to produce the image. Pregnant women and ...

  8. Calculating patient specific doses in X-ray diagnostics and from radiopharmaceuticals

    International Nuclear Information System (INIS)

    Lampinen, J.

    2000-01-01

    The risk associated with exposure to ionising radiation is dependent on the characteristics of the exposed individual. The size and structure of the individual influences the absorbed dose distribution in the organs. Traditional methods used to calculate the patient organ doses are based on standardised calculation phantoms, which neglect the variance of the patient size or even sex. When estimating the radiation dose of an individual patient, patient specific calculation methods must be used. Methods for patient specific dosimetry in the fields of X-ray diagnostics and diagnostic and therapeutic use of radiopharmaceuticals were proposed in this thesis. A computer program, ODS-60, for calculating organ doses from diagnostic X-ray exposures was presented. The calculation is done in a patient specific phantom with depth dose and profile algorithms fitted to Monte Carlo simulation data from a previous study. Improvements to the version reported earlier were introduced, e.g. bone attenuation was implemented. The applicability of the program to determine patient doses from complex X-ray examinations (barium enema examination) was studied. The conversion equations derived for female and male patients as a function of patient weight gave the smallest deviation from the actual patient doses when compared to previous studies. Another computer program, Intdose, was presented for calculation of the dose distribution from radiopharmaceuticals. The calculation is based on convolution of an isotope specific point dose kernel with activity distribution, obtained from single photon emission computed tomography (SPECT) images. Anatomical information is taken from magnetic resonance (MR) or computed tomography (CT) images. According to a phantom study, Intdose agreed within 3 % with measurements. For volunteers administered diagnostic radiopharmaceuticals, the results given by Intdose were found to agree with traditional methods in cases of medium sized patients. For patients

  9. Compression of the digitized X-ray images

    International Nuclear Information System (INIS)

    Terae, Satoshi; Miyasaka, Kazuo; Fujita, Nobuyuki; Takamura, Akio; Irie, Goro; Inamura, Kiyonari.

    1987-01-01

    Medical images are using an increased amount of space in the hospitals, while they are not accessed easily. Thus, suitable data filing system and precise data compression will be necessitated. Image quality was evaluated before and after image data compression, using local filing system (MediFile 1000, NEC Co.) and forty-seven modes of compression parameter. For this study X-ray images of 10 plain radiographs and 7 contrast examinations were digitized using a film reader of CCD sensor in MediFile 1000. Those images were compressed into forty-seven kinds of image data to save in an optical disc and then the compressed images were reconstructed. Each reconstructed image was compared with non-compressed images in respect to several regions of our interest by four radiologists. Compression and extension of radiological images were promptly made by employing the local filing system. Image quality was much more affected by the ratio of data compression than by the mode of parameter itself. In another word, the higher compression ratio became, the worse the image quality were. However, image quality was not significantly degraded until the compression ratio was about 15: 1 on plain radiographs and about 8: 1 on contrast studies. Image compression by this technique will be admitted by diagnostic radiology. (author)

  10. Imaging properties and its improvements of scanning/imaging x-ray microscope

    International Nuclear Information System (INIS)

    Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio

    2016-01-01

    A scanning / imaging X-ray microscope (SIXM) system has been developed at SPring-8. The SIXM consists of a scanning X-ray microscope with a one-dimensional (1D) X-ray focusing device and an imaging (full-field) X-ray microscope with a 1D X-ray objective. The motivation of the SIXM system is to realize a quantitative and highly-sensitive multimodal 3D X-ray tomography by taking advantages of both the scanning X-ray microscope using multi-pixel detector and the imaging X-ray microscope. Data acquisition process of a 2D image is completely different between in the horizontal direction and in the vertical direction; a 1D signal is obtained with the linear-scanning while the other dimensional signal is obtained with the imaging optics. Such condition have caused a serious problem on the imaging properties that the imaging quality in the vertical direction has been much worse than that in the horizontal direction. In this paper, two approaches to solve this problem will be presented. One is introducing a Fourier transform method for phase retrieval from one phase derivative image, and the other to develop and employ a 1D diffuser to produce an asymmetrical coherent illumination

  11. Effective high voltage at X-ray tube in hard X-ray chest imaging

    International Nuclear Information System (INIS)

    Klein, J.

    1987-01-01

    The FRG standard TGL 36 661 (March 1980) for synoptical chest pictures of large size in adults specifies the 120 kV voltage at the X-ray tube together with maximal, 100% use of the capacity of the tube (hard picture, short exposure time). By means of circular recording and by measuring the high voltage at the X-ray tube it was quantitatively shown that the effective voltage during exposure is (according to the exposure time and the attenuation phase of the generator) always lower than the set-up voltage of 120 kV. This phenomenon is the more marked the shorter the actual exposure time in comparison with the attenuation phase of the generator. The typical characteristic of a hard X-ray chest picture is thus not given only by the setting-up of voltage. The impact of the reduction in voltage is thus quantitatively shown also from the aspect of the radiation burden for the patient. (author). 7 figs., 8 refs

  12. Exposure doses of the patient and the medical staff during urological X-ray examens

    International Nuclear Information System (INIS)

    Vogel, H.; Loehr, H.; Haug, P.; Schuett, B.

    1977-01-01

    During 32 intravenous urografies and 48 angiografies of the kidney and the suprarenal glands the X-ray doses at the patient's skin and gonades were determined. During the angiografies the doses were mesured at the hands. the gonades and the front (eyes) of the medical staff. The results are discussed. Because the X-ray doses are relatively high, the number of the pictures and the exposure time is to be reduced to the minimum. Clinical experience and special knowledge is the best X-ray protection. (orig.) [de

  13. Response of the 'patient dose calibrator' chamber for incident positions and sizes of X-ray fields

    International Nuclear Information System (INIS)

    Oliveira, Cassio M.; Abrantes, Marcos Eugenio S.; Ferreira, Flavia C. Bastos; Lacerda, Marco A. de Souza; Alonso, Thessa C.; Silva, Teogenes A. da; Oliveira, Paulo Marcio C.

    2009-01-01

    The evaluation of patient doses is an important tool for optimizing radiodiagnostic medical procedures with conventional X-ray equipment and for improving the quality of the radiographic image. The Patient Dose Calibrator (PDC) chamber is a dosimetric instrument that is used in the evaluation of the air kerma-area product (P KA ) quantity aiming the reduction of patient doses. The objective this work was to study the P KA variation caused by different field incident positions and sizes of the X-ray beam on the PDC chamber. Results showed that the PDC chamber has repeatability lower than 0.6%, beam position dependence of 3% and linearity response within ± 6%; these characteristics are to be taken into account during evaluation of the radiological protection conditions of conventional x-ray equipment. (author)

  14. The model of illumination-transillumination for image enhancement of X-ray images

    Energy Technology Data Exchange (ETDEWEB)

    Lyu, Kwang Yeul [Shingu College, Sungnam (Korea, Republic of); Rhee, Sang Min [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2001-06-01

    In digital image processing, the homomorphic filtering approach is derived from an illumination - reflectance model of the image. It can also be used with an illumination-transillumination model X-ray film. Several X-ray images were applied to enhancement with histogram equalization and homomorphic filter based on an illumination-transillumination model. The homomorphic filter has proven theoretical claim of image density range compression and balanced contrast enhancement, and also was found a valuable tool to process analog X-ray images to digital images.

  15. Effects of X-rays spectrum on the dose; Efectos del espectro de rayos X sobre la dosis

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez I, J. L.; Hernandez A, P. L.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Rivera M, T., E-mail: johann_greenday@hotmail.com [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria No. 694, 11500 Mexico D. F. (Mexico)

    2015-10-15

    The X-ray equipment for diagnosis comes in different sizes and shapes depending on the scan type to perform. The X-ray spectrum is the energy distribution of the beam photons and consists of a continuous spectrum of photons braking and discrete spectrum due to the characteristic photons. The knowledge of the X-rays spectrum is important to understand like they affect the voltage changes (k Vp), current (m A), time (s) and the type of filter in the interaction mechanisms between X-rays and patient's body, the image receptor or other material that gets in the beam. Across the spectrum can be estimated the absorbed dose in any point of the patient, the quality of the image and the scattered radiation (which is related to the dose received by the equipment operator). The Monte Carlo method was used by MCNP5 code to calculate the spectrum of X-rays that occurs when a monoenergetic electron beam of 250 keV interact with targets of Mo, Rh and W. The spectra were calculated with and without filter, and the values of ambient dose equivalent were estimated, as well as the air kerma. (Author)

  16. Imaging bacterial spores by soft-x-ray microscopy

    International Nuclear Information System (INIS)

    Stead, A.D.; Ford, T.W.; Judge, J.

    1997-01-01

    Bacterial spores are able to survive dehydration, but neither the physiological nor structural basis of this have been fully elucidated. Furthermore, once hydrated, spores often require activation before they will germinate. Several treatments can be used to activate spores, but in the case of Bacillus subtlis the most effective is heat treatment. The physiological mechanism associated with activation is also not understood, but some workers suggest that the loss of calcium from the spores may be critical. However, just prior to germination, the spores change from being phase bright to phase dark when viewed by light microscopy. Imaging spores by soft x-ray microscopy is possible without fixation. Thus, in contrast to electron microscopy, it is possible to compare the structure of dehydrated and hydrated spores in a manner not possible previously. A further advantage is that it is possible to monitor individual spores by phase contrast light microscopy immediately prior to imaging with soft x-rays; whereas, with both electron microscopy and biochemical studies, it is a population of spores being studied without knowledge of the phase characteristics of individual spores. This study has therefore tried to compare dehydrated and hydrated spores and to determine if there is a mass loss from individual spores as they pass the transition from being phase bright to phase dark

  17. Imaging escape gated MPWC for hard X-ray astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Ubertini, P.; Bazzano, A.; Boccaccini, L.; La Padula, C.; Mastropietro, M.; Patriarca, R.; Polcaro, V.F.; Barbareschi, L.; Perotti, F.; Villa, G.

    1983-11-15

    A scientific forward step in the hard X-ray and soft gamma-ray astronomy will only be possible with the use of a new generation of space borne instruments. Their main characteristics have to be the two-dimensional imaging capability over a large collecting area and the fine spectral resolution in order to discriminate between the weak signal coming from cosmic sources to be detected and the strong background induced by cosmic rays, in the space environment, on the detector. To reach this goal we have developed a new hard X-ray position sensitive proportional counter operating with the escape gate technique in the range 15-150 keV, to be used together with a pseudo-random coded mask in order to obtain sky images. The detector is a high pressure (5 bar) xenon-argon-isobutane filled chamber with a spatial resolution of 30x2 mm and a spectral resolution of 5% at 60 keV on the sensitive area of 3000 cm/sup 2/.

  18. Imaging bacterial spores by soft-x-ray microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Stead, A.D.; Ford, T.W. [Univ. of London, Surrey (United Kingdom); Judge, J. [Unilever plc, Sharnbrook (United Kingdom)] [and others

    1997-04-01

    Bacterial spores are able to survive dehydration, but neither the physiological nor structural basis of this have been fully elucidated. Furthermore, once hydrated, spores often require activation before they will germinate. Several treatments can be used to activate spores, but in the case of Bacillus subtlis the most effective is heat treatment. The physiological mechanism associated with activation is also not understood, but some workers suggest that the loss of calcium from the spores may be critical. However, just prior to germination, the spores change from being phase bright to phase dark when viewed by light microscopy. Imaging spores by soft x-ray microscopy is possible without fixation. Thus, in contrast to electron microscopy, it is possible to compare the structure of dehydrated and hydrated spores in a manner not possible previously. A further advantage is that it is possible to monitor individual spores by phase contrast light microscopy immediately prior to imaging with soft x-rays; whereas, with both electron microscopy and biochemical studies, it is a population of spores being studied without knowledge of the phase characteristics of individual spores. This study has therefore tried to compare dehydrated and hydrated spores and to determine if there is a mass loss from individual spores as they pass the transition from being phase bright to phase dark.

  19. IXPE the Imaging X-ray Polarimetry Explorer

    Science.gov (United States)

    Soffitta, Paolo

    2017-08-01

    IXPE, the Imaging X-ray Polarimetry Explorer, has been selected as a NASA SMEX mission to be flown in 2021. It will perform polarimetry resolved in energy, in time and in angle as a break-through in High Energy Astrophysics. IXPE promises to 're-open', after 40 years, a window in X-ray astronomy adding two more observables to the usual ones. It will directly measure the geometrical parameters of many different classes of sources eventually breaking possible degeneracies. The probed angular scales (30") are capable of producing the first X-ray polarization maps of extended objects with scientifically relevant sensitivity. This will permit mapping the magnetic fields in Pulsar Wind Nebulae and Super-Nova Remnants at the acceleration sites of 10-100 TeV electrons. Additionally, it will probe vacuum birefringence effects in systems with magnetic fields far larger than those reachable with experiments on Earth. The payload of IXPE consists of three identical telescopes with mirrors provided by MSFC/NASA. The focal plane is provided by ASI with IAPS/INAF responsible for the overall instrument that includes detector units that are provided by INFN. ASI also provides, in kind, the Malindi Ground Station. LASP is responsible for the Mission Operation Center while the Science Operation Center is at MSFC. The operations phase lasts at least two years. All the data including those related to polarization will be made available quickly to the general user. In this paper we present the mission, its payload and we discuss a few examples of astrophysical targets.

  20. Feasibility study on X-ray source with pinhole imaging method

    International Nuclear Information System (INIS)

    Qiu Rui; Li Junli

    2007-01-01

    In order to verify the feasibility of study on X-ray source with pinhole imaging method, and optimize the design of X-ray pinhole imaging system, an X-ray pinhole imaging equipment was set up. The change of image due to the change of the position and intensity of X-ray source was estimated with mathematical method and validated with experiment. The results show that the change of the spot position and gray of the spot is linearly related with the change of the position and intensity of X-ray source, so it is feasible to study X-ray source with pinhole imaging method in this application. The results provide some references for the design of X-ray pinhole imaging system. (authors)

  1. High energy X-ray phase and dark-field imaging using a random absorption mask.

    Science.gov (United States)

    Wang, Hongchang; Kashyap, Yogesh; Cai, Biao; Sawhney, Kawal

    2016-07-28

    High energy X-ray imaging has unique advantage over conventional X-ray imaging, since it enables higher penetration into materials with significantly reduced radiation damage. However, the absorption contrast in high energy region is considerably low due to the reduced X-ray absorption cross section for most materials. Even though the X-ray phase and dark-field imaging techniques can provide substantially increased contrast and complementary information, fabricating dedicated optics for high energies still remain a challenge. To address this issue, we present an alternative X-ray imaging approach to produce transmission, phase and scattering signals at high X-ray energies by using a random absorption mask. Importantly, in addition to the synchrotron radiation source, this approach has been demonstrated for practical imaging application with a laboratory-based microfocus X-ray source. This new imaging method could be potentially useful for studying thick samples or heavy materials for advanced research in materials science.

  2. X-ray fluorescence method for trace analysis and imaging

    International Nuclear Information System (INIS)

    Hayakawa, Shinjiro

    2000-01-01

    X-ray fluorescence analysis has a long history as conventional bulk elemental analysis with medium sensitivity. However, with the use of synchrotron radiation x-ray fluorescence method has become a unique analytical technique which can provide tace elemental information with the spatial resolution. To obtain quantitative information of trace elemental distribution by using the x-ray fluorescence method, theoretical description of x-ray fluorescence yield is described. Moreover, methods and instruments for trace characterization with a scanning x-ray microprobe are described. (author)

  3. Analysis of the frequency components of X-ray images

    International Nuclear Information System (INIS)

    Matsuo, Satoru; Komizu, Mitsuru; Kida, Tetsuo; Noma, Kazuo; Hashimoto, Keiji; Onishi, Hideo; Masuda, Kazutaka

    1997-01-01

    We examined the relation between the frequency components of x-ray images of the chest and phalanges and their read sizes for digitizing. Images of the chest and phalanges were radiographed using three types of screens and films, and the noise images in background density were digitized with a drum scanner, changing the read sizes. The frequency components for these images were evaluated by converting them to the secondary Fourier to obtain the power spectrum and signal to noise ratio (SNR). After changing the cut-off frequency on the power spectrum to process a low pass filter, we also examined the frequency components of the images in relation to the normalized mean square error (NMSE) for the image converted to reverse Fourier and the original image. Results showed that the frequency components were 2.0 cycles/mm for the chest image and 6.0 cycles/mm for the phalanges. Therefore, it is necessary to collect data applying the read sizes of 200 μm and 50 μm for the chest and phalangeal images, respectively, in order to digitize these images without loss of their frequency components. (author)

  4. Hybrid lightweight X-ray optics for half arcsecond imaging

    Science.gov (United States)

    Reid, Paul

    This proposal is for the development of grazing incidence optics suitable to meet the 0.5 arcsec imaging and 2.3 square meter effective area requirements of the X-ray Surveyor mission concept, currently under study by NASA. Our approach is to combine two promising technologies, as yet individually unproven at the 0.5 arcsec level, into a hybrid mirror approach. The two technologies are thin piezoelectric film adjustable optics under development at SAO and PSU, and differential deposition under development at NASA MSFC. These technologies are complementary: adjustable optics are best suited to fixing low spatial frequency errors due to piezoelectric cell size limitations, and differential deposition is best suited for fixing mid-spatial frequency errors so as to limit the amount of material that must be deposited. Thus, the combination of the two techniques extends the bandwidth of figure errors that can be corrected beyond what it was for either individual technique. Both technologies will be applied to fabricate Wolter-I mirror segment from single thermally formed glass substrates. This work is directed at mirror segments only (not full shells), as we believe segments are the most appropriate for developing the 3 m diameter X-ray Surveyor high resolution mirror. In this program we will extend differential deposition to segment surfaces (from line profiles), investigate the most realistic error bandwidths for each technology, and determine the impacts of one technologys processing steps on the other to find if there is an optimal order to combining the technologies. In addition, we will also conduct a conical/cylindrical mirror metrology "round-robin," to cross-calibrate the different cylindrical metrology to one another as a means of minimizing systematic errors. Finally, we will examine the balancing and compensating of mirror stress due to the various thin films employed (piezoelectric layer, differential deposition, X-ray reflecting layer(s)) with an eye to

  5. An update on carbon nanotube-enabled X-ray sources for biomedical imaging.

    Science.gov (United States)

    Puett, Connor; Inscoe, Christina; Hartman, Allison; Calliste, Jabari; Franceschi, Dora K; Lu, Jianping; Zhou, Otto; Lee, Yueh Z

    2018-01-01

    A new imaging technology has emerged that uses carbon nanotubes (CNT) as the electron emitter (cathode) for the X-ray tube. Since the performance of the CNT cathode is controlled by simple voltage manipulation, CNT-enabled X-ray sources are ideal for the repetitive imaging steps needed to capture three-dimensional information. As such, they have allowed the development of a gated micro-computed tomography (CT) scanner for small animal research as well as stationary tomosynthesis, an experimental technology for large field-of-view human imaging. The small animal CT can acquire images at specific points in the respiratory and cardiac cycles. Longitudinal imaging therefore becomes possible and has been applied to many research questions, ranging from tumor response to the noninvasive assessment of cardiac output. Digital tomosynthesis (DT) is a low-dose and low-cost human imaging tool that captures some depth information. Known as three-dimensional mammography, DT is now used clinically for breast imaging. However, the resolution of currently-approved DT is limited by the need to swing the X-ray source through space to collect a series of projection views. An array of fixed and distributed CNT-enabled sources provides the solution and has been used to construct stationary DT devices for breast, lung, and dental imaging. To date, over 100 patients have been imaged on Institutional Review Board-approved study protocols. Early experience is promising, showing an excellent conspicuity of soft-tissue features, while also highlighting technical and post-acquisition processing limitations that are guiding continued research and development. Additionally, CNT-enabled sources are being tested in miniature X-ray tubes that are capable of generating adequate photon energies and tube currents for clinical imaging. Although there are many potential applications for these small field-of-view devices, initial experience has been with an X-ray source that can be inserted into the

  6. A method for describing the doses delivered by transmission x-ray computed tomography

    International Nuclear Information System (INIS)

    Shope, T.B.; Gagne, R.M.; Johnson, G.C.

    1981-01-01

    A method for describing the absorbed dose delivered by x-ray transmission computed tomography (CT) is proposed which provides a means to characterize the dose resulting from CT procedures consisting of a series of adjacent scans. The dose descriptor chosen is the average dose at several locations in the imaged volume of the central scan of the series. It is shown that this average dose, as defined, for locations in the central scan of the series can be obtained from the integral of the dose profile perpendicular to the scan plane at these same locations for a single scan. This method for estimating the average dose from a CT procedure has been evaluated as a function of the number of scans in the multiple scan procedure and location in the dosimetry phantom using single scan dose profiles obtained from five different types of CT systems. For the higher dose regions in the phantoms, the multiple scan dose descriptor derived from the single scan dose profiles overestimates the multiple scan average dose by no more than 10%, provided the procedure consists of at least eight scans

  7. Low-dose CT of the paranasal sinuses. Minimizing X-ray exposure with spectral shaping

    Energy Technology Data Exchange (ETDEWEB)

    Wuest, Wolfgang [Friedrich-Alexander-University Erlangen-Nuremberg, Radiological Institute, Erlangen (Germany); Radiological Institute, Erlangen (Germany); May, Matthias; Saake, Marc; Brand, Michael; Uder, Michael; Lell, Michael [Friedrich-Alexander-University Erlangen-Nuremberg, Radiological Institute, Erlangen (Germany)

    2016-11-15

    Shaping the energy spectrum of the X-ray beam has been shown to be beneficial in low-dose CT. This study's aim was to investigate dose and image quality of tin filtration at 100 kV for pre-operative planning in low-dose paranasal CT imaging in a large patient cohort. In a prospective trial, 129 patients were included. 64 patients were randomly assigned to the study protocol (100 kV with additional tin filtration, 150mAs, 192 x 0.6-mm slice collimation) and 65 patients to the standard low-dose protocol (100 kV, 50mAs, 128 x 0.6-mm slice collimation). To assess the image quality, subjective parameters were evaluated using a five-point scale. This scale was applied on overall image quality and contour delineation of critical anatomical structures. All scans were of diagnostic image quality. Bony structures were of good diagnostic image quality in both groups, soft tissues were of sufficient diagnostic image quality in the study group because of a high level of noise. Radiation exposure was very low in both groups, but significantly lower in the study group (CTDI{sub vol} 1.2 mGy vs. 4.4 mGy, p < 0.001). Spectral optimization (tin filtration at 100 kV) allows for visualization of the paranasal sinus with sufficient image quality at a very low radiation exposure. (orig.)

  8. X-ray diffraction imaging of biological cells

    CERN Document Server

    Nakasako, Masayoshi

    2018-01-01

    In this book, the author describes the development of the experimental diffraction setup and structural analysis of non-crystalline particles from material science and biology. Recent advances in X-ray free electron laser (XFEL)-coherent X-ray diffraction imaging (CXDI) experiments allow for the structural analysis of non-crystalline particles to a resolution of 7 nm, and to a resolution of 20 nm for biological materials. Now XFEL-CXDI marks the dawn of a new era in structural analys of non-crystalline particles with dimensions larger than 100 nm, which was quite impossible in the 20th century. To conduct CXDI experiments in both synchrotron and XFEL facilities, the author has developed apparatuses, named KOTOBUKI-1 and TAKASAGO-6 for cryogenic diffraction experiments on frozen-hydrated non-crystalline particles at around 66 K. At the synchrotron facility, cryogenic diffraction experiments dramatically reduce radiation damage of specimen particles and allow tomography CXDI experiments. In addition, in XFEL ex...

  9. Ultrafast X-ray Imaging of Fuel Sprays

    Science.gov (United States)

    Wang, Jin

    2007-01-01

    Detailed analysis of fuel sprays has been well recognized as an important step for optimizing the operation of internal combustion engines to improve efficiency and reduce emissions. Ultrafast radiographic and tomographic techniques have been developed for probing the fuel distribution close to the nozzles of direct-injection diesel and gasoline injectors. The measurement was made using x-ray absorption of monochromatic synchrotron-generated radiation, allowing quantitative determination of the fuel distribution in this optically impenetrable region with a time resolution on the order of 1 μs. Furthermore, an accurate 3-dimensional fuel-density distribution, in the form of fuel volume fraction, was obtained by the time-resolved computed tomography. These quantitative measurements constitute the most detailed near-nozzle study of a fuel spray to date. With high-energy and high-brilliance x-ray beams available at the Advanced Photon Source, propagation-based phase-enhanced imaging was developed as a unique metrology technique to visualize the interior of an injection nozzle through a 3-mm-thick steel with a 10-μs temporal resolution, which is virtually impossible by any other means.

  10. Ultrafast X-ray Imaging of Fuel Sprays

    International Nuclear Information System (INIS)

    Wang Jin

    2007-01-01

    Detailed analysis of fuel sprays has been well recognized as an important step for optimizing the operation of internal combustion engines to improve efficiency and reduce emissions. Ultrafast radiographic and tomographic techniques have been developed for probing the fuel distribution close to the nozzles of direct-injection diesel and gasoline injectors. The measurement was made using x-ray absorption of monochromatic synchrotron-generated radiation, allowing quantitative determination of the fuel distribution in this optically impenetrable region with a time resolution on the order of 1 μs. Furthermore, an accurate 3-dimensional fuel-density distribution, in the form of fuel volume fraction, was obtained by the time-resolved computed tomography. These quantitative measurements constitute the most detailed near-nozzle study of a fuel spray to date. With high-energy and high-brilliance x-ray beams available at the Advanced Photon Source, propagation-based phase-enhanced imaging was developed as a unique metrology technique to visualize the interior of an injection nozzle through a 3-mm-thick steel with a 10-μs temporal resolution, which is virtually impossible by any other means

  11. X-ray imaging spectroscopic diagnostics on Nike

    Science.gov (United States)

    Aglitskiy, Y.; Karasik, M.; Serlin, V.; Weaver, J. L.; Oh, J.; Obenschain, S. P.; Ralchenko, Yu.

    2017-10-01

    Electron temperature and density diagnostics of the laser plasma produced within the focal spot of the NRL's Nike laser are being explored with the help of X-ray imaging spectroscopy. Spectra of He-like and H-like ions were taken by Nike focusing spectrometers in a range of lower (1.8 kev, Si XIV) and higher (6.7 kev, Fe XXV) x-ray energies. Data that were obtained with spatial resolution were translated into the temperature and density as functions of distance from the target. As an example electron density was determined from He-like satellites to Ly-alpha in Si XIV. The dielectronic satellites with intensity ratios that are sensitive to collisional transfer of population between different triplet groups of double-excited states 2l2l' in Si XIII were observed with high spatial and spectral resolution Lineouts taken at different axial distances from the planar Si target show changing spectral shapes due to the different electron densities as determined by supporting non-LTE simulations. These shapes are relatively insensitive to the plasma temperature which was measured using different spectral lines. This work was supported by the US DOE/NNSA.

  12. Industrial X-ray imaging based on scintillators and CMOS APS array: direct X-ray irradiation effects

    International Nuclear Information System (INIS)

    Kim, Kwang Hyun; Jeon, Sung Chae; Kim, Young Soo; Cho, Gyuseong

    2005-01-01

    To see the effects of the direct X-ray in a Lanex screen-coupled CMOS APS imager, we measured modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE). These measurements were performed under the condition of non-destructive test (NDT). By increasing the cumulative exposure on the imager, the MTF was degraded, and also leading to the DQE degradation. Each parameter changed by the exposure is described in detail

  13. X-ray imaging and detection using plastic scintillating fibers

    CERN Document Server

    Ikhlef, A; Beddar, A S

    2000-01-01

    This paper discusses the application of plastic scintillating fiber array in X-ray imaging with low-energy radiation. This array is coupled to a multichannel intensified photocathode and then to a CCD detector via a fiber optics taper. The length of the fiber array is experimentally optimized for the radiation used. We found here that the length of the fibers (interaction medium) does not contribute too much in the degradation of the spatial resolution under 10 keV irradiation along the axis of the fiber array. Modulation Transfer Function (MTF) measurements of the PSF array are compared to the optics MTF of the imaging system (without the sample) and that cross-talk in the fiber array is found to be negligible for a fiber array thickness of 20 mm.

  14. Optimization and energy spectra of x-ray to be used for imaging

    International Nuclear Information System (INIS)

    Nakamori, Nobuyuki; Kanamori, Hitoshi

    1979-01-01

    The relations of the spectra of X-ray used for diagnosis to the absorbed dose of patients and X-ray information are now being investigated by a number of investigators. Here the problems and the trends of the investigations at present are described. Advent of semiconductor detectors has improved the accuracy of measuring X-ray spectra very rapidly. However, since the semiconductor detectors themselves utilize X-ray photon absorption, calibration curves must be prepared for obtaining the true X-ray spectra. Though there are methods of theoretically determining X-ray spectra, no definite theoretical formula is found. Thus, the derivation of an empirical equation based on measured data would be the most fundamental problem. Interactions in an object and the change of X-ray spectra are described on the case of monochromatic and continuous X-ray irradiation. As mentioned above, beam hardening occurs when X-ray enters a matter deep, because the interactions between X-ray and the matter depend upon the photon energy. There are a few methods for correcting the variation of CT (computed tomography) number due to beam hardening. However, prior to this, there are two methods of representing continuous X-ray with single energy, and the unification of the methods or a new way of defining X-ray quality is needed. It has been and is always desirable that monochromatic X-ray source becomes to be useable, and various methods are proposed. (Wakatsuki, Y.)

  15. Problems and image processing in X-ray film digitization

    International Nuclear Information System (INIS)

    Kato, Syousuke; Yoshita, Hisashi; Kuranishi, Makoto; Itoh, Hajime; Mori, Kouichi; Konishi, Minoru

    1992-01-01

    Aiming at the realization of PACS, a study was conducted on the present state of, and various problems associated with, X-ray film digitization using a He-Ne laser-type film digitizer. Image quality was evaluated physically and clinically. With regard to the gradation specificity, the linear specificity was shown in a dynamic range of 4 figures. With regard to resolution specificity, visual evaluation was performed using a Hawlet Chart, with almost no difference being found between the CRT and laser printer output images and the decrease in resolution becoming more pronounced as the sampling pitch became greater. Clinical evaluation was performed with reference to the literature. The general evaluation of the clinicians was that although there was some deterioration for all of the shadows, (I have read this many times, but could not understand the last part.) by performing each of the kinds of image-processing enhancement of diagnostic ability was achieved, with a diagnosis being possible. The problem of unhindered diagnosis due to the development of artifacts from optical interference of the grid images projected onto the clinical pictures and digitizer sampling pitch was studied. As countermeasures, the use of a high density grid and adoption of a low-pass filter were useful in impending the development of artifacts. Regarding the operating problems, the inputting of index information requires a considerable number of manhours and a method of automatic recognition from digital data was introduced to overcome this problem. As future-prospects, the concepts of a practical system of X-ray film digitization and a film-screen system adapted to digitization were described. (author)

  16. Problems and image processing in X-ray film digitization

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Syousuke; Yoshita, Hisashi; Kuranishi, Makoto; Itoh, Hajime; Mori, Kouichi; Konishi, Minoru (Toyama Medical and Pharmaceutical Univ. (Japan). Hospital)

    1992-11-01

    Aiming at the realization of PACS, a study was conducted on the present state of, and various problems associated with, X-ray film digitization using a He-Ne laser-type film digitizer. Image quality was evaluated physically and clinically. With regard to the gradation specificity, the linear specificity was shown in a dynamic range of 4 figures. With regard to resolution specificity, visual evaluation was performed using a Hawlet Chart, with almost no difference being found between the CRT and laser printer output images and the decrease in resolution becoming more pronounced as the sampling pitch became greater. Clinical evaluation was performed with reference to the literature. The general evaluation of the clinicians was that although there was some deterioration for all of the shadows, (I have read this many times, but could not understand the last part.) by performing each of the kinds of image-processing enhancement of diagnostic ability was achieved, with a diagnosis being possible. The problem of unhindered diagnosis due to the development of artifacts from optical interference of the grid images projected onto the clinical pictures and digitizer sampling pitch was studied. As countermeasures, the use of a high density grid and adoption of a low-pass filter were useful in impending the development of artifacts. Regarding the operating problems, the inputting of index information requires a considerable number of manhours and a method of automatic recognition from digital data was introduced to overcome this problem. As future-prospects, the concepts of a practical system of X-ray film digitization and a film-screen system adapted to digitization were described. (author).

  17. Images of the laser entrance hole from the static x-ray imager at NIF.

    Science.gov (United States)

    Schneider, M B; Jones, O S; Meezan, N B; Milovich, J L; Town, R P; Alvarez, S S; Beeler, R G; Bradley, D K; Celeste, J R; Dixit, S N; Edwards, M J; Haugh, M J; Kalantar, D H; Kline, J L; Kyrala, G A; Landen, O L; MacGowan, B J; Michel, P; Moody, J D; Oberhelman, S K; Piston, K W; Pivovaroff, M J; Suter, L J; Teruya, A T; Thomas, C A; Vernon, S P; Warrick, A L; Widmann, K; Wood, R D; Young, B K

    2010-10-01

    The static x-ray imager at the National Ignition Facility is a pinhole camera using a CCD detector to obtain images of Hohlraum wall x-ray drive illumination patterns seen through the laser entrance hole (LEH). Carefully chosen filters, combined with the CCD response, allow recording images in the x-ray range of 3-5 keV with 60 μm spatial resolution. The routines used to obtain the apparent size of the backlit LEH and the location and intensity of beam spots are discussed and compared to predictions. A new soft x-ray channel centered at 870 eV (near the x-ray peak of a 300 eV temperature ignition Hohlraum) is discussed.

  18. Terahertz pulsed imaging for the monitoring of dental caries: a comparison with x-ray imaging

    Science.gov (United States)

    Karagoz, Burcu; Kamburoglu, Kıvanc; Altan, Hakan

    2017-07-01

    Dental caries in sliced samples are investigated using terahertz pulsed imaging. Frequency domain terahertz response of these structures consistent with X-ray imaging results show the potential of this technique in the detection of early caries.

  19. Preliminary research on dual-energy X-ray phase-contrast imaging

    Science.gov (United States)

    Han, Hua-Jie; Wang, Sheng-Hao; Gao, Kun; Wang, Zhi-Li; Zhang, Can; Yang, Meng; Zhang, Kai; Zhu, Pei-Ping

    2016-04-01

    Dual-energy X-ray absorptiometry (DEXA) has been widely applied to measure the bone mineral density (BMD) and soft-tissue composition of the human body. However, the use of DEXA is greatly limited for low-Z materials such as soft tissues due to their weak absorption, while X-ray phase-contrast imaging (XPCI) shows significantly improved contrast in comparison with the conventional standard absorption-based X-ray imaging for soft tissues. In this paper, we propose a novel X-ray phase-contrast method to measure the area density of low-Z materials, including a single-energy method and a dual-energy method. The single-energy method is for the area density calculation of one low-Z material, while the dual-energy method aims to calculate the area densities of two low-Z materials simultaneously. Comparing the experimental and simulation results with the theoretical ones, the new method proves to have the potential to replace DEXA in area density measurement. The new method sets the prerequisites for a future precise and low-dose area density calculation method for low-Z materials. Supported by Major State Basic Research Development Program (2012CB825800), Science Fund for Creative Research Groups (11321503) and National Natural Science Foundation of China (11179004, 10979055, 11205189, 11205157)

  20. From synchrotron radiation to lab source: advanced speckle-based X-ray imaging using abrasive paper

    Science.gov (United States)

    Wang, Hongchang; Kashyap, Yogesh; Sawhney, Kawal

    2016-02-01

    X-ray phase and dark-field imaging techniques provide complementary and inaccessible information compared to conventional X-ray absorption or visible light imaging. However, such methods typically require sophisticated experimental apparatus or X-ray beams with specific properties. Recently, an X-ray speckle-based technique has shown great potential for X-ray phase and dark-field imaging using a simple experimental arrangement. However, it still suffers from either poor resolution or the time consuming process of collecting a large number of images. To overcome these limitations, in this report we demonstrate that absorption, dark-field, phase contrast, and two orthogonal differential phase contrast images can simultaneously be generated by scanning a piece of abrasive paper in only one direction. We propose a novel theoretical approach to quantitatively extract the above five images by utilising the remarkable properties of speckles. Importantly, the technique has been extended from a synchrotron light source to utilise a lab-based microfocus X-ray source and flat panel detector. Removing the need to raster the optics in two directions significantly reduces the acquisition time and absorbed dose, which can be of vital importance for many biological samples. This new imaging method could potentially provide a breakthrough for numerous practical imaging applications in biomedical research and materials science.

  1. Microbubbles as contrast agent for in-line x-ray phase-contrast imaging

    International Nuclear Information System (INIS)

    Xi Yan; Zhao Jun; Tang Rongbiao; Wang Yujie

    2011-01-01

    In the present study, we investigated the potential of gas-filled microbubbles as contrast agents for in-line x-ray phase-contrast imaging (PCI) in biomedical applications. When imaging parameters are optimized, the microbubbles function as microlenses that focus the incoming x-rays to form bright spots, which can significantly enhance the image contrast. Since microbubbles have been shown to be safe contrast agents in clinical ultrasonography, this contrast-enhancement procedure for PCI may have promising utility in biomedical applications, especially when the dose of radiation is a serious concern. In this study, we performed both numerical simulations and ex vivo experiments to investigate the formation of the contrast and the effectiveness of microbubbles as contrast agents in PCI.

  2. Pick up screens for x-ray image intensifier tubes employing evaporated activated scintillator layer

    International Nuclear Information System (INIS)

    Spicer, W.E.

    1976-01-01

    The present invention relates in general to methods for making pick-up screens for x-ray image intensifier tubes and, more particularly, to an improved method wherein the x-ray fluorescent phosphor screen element is formed by evaporation of an alkali metal halide material in vacuum and condensing the evaporated material on an x-ray transparent portion of the x-ray intensifier tube, whereby a curved x-ray image pick-up screen is formed which has improved quantum efficiency and resolution. Such improved x-ray image intensifier tubes are especially useful for, but not limited in use to x-ray systems and for intensifying gamma ray images obtained in applications of nuclear medicine. 7 claims, 5 drawing figures

  3. Electron cyclotron resonance ion source plasma characterization by X-ray spectroscopy and X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mascali, David, E-mail: davidmascali@lns.infn.it; Castro, Giuseppe; Celona, Luigi; Neri, Lorenzo; Gammino, Santo [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Biri, Sándor; Rácz, Richárd; Pálinkás, József [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/c, H-4026 Debrecen (Hungary); Caliri, Claudia [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Università degli Studi di Catania, Dip.to di Fisica e Astronomia, via Santa Sofia 64, 95123 Catania (Italy); Romano, Francesco Paolo [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); CNR, Istituto per i Beni Archeologici e Monumentali, Via Biblioteca 4, 95124 Catania (Italy); Torrisi, Giuseppe [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Università Mediterranea di Reggio Calabria, DIIES, Via Graziella, I-89100 Reggio Calabria (Italy)

    2016-02-15

    An experimental campaign aiming to investigate electron cyclotron resonance (ECR) plasma X-ray emission has been recently carried out at the ECRISs—Electron Cyclotron Resonance Ion Sources laboratory of Atomki based on a collaboration between the Debrecen and Catania ECR teams. In a first series, the X-ray spectroscopy was performed through silicon drift detectors and high purity germanium detectors, characterizing the volumetric plasma emission. The on-purpose developed collimation system was suitable for direct plasma density evaluation, performed “on-line” during beam extraction and charge state distribution characterization. A campaign for correlating the plasma density and temperature with the output charge states and the beam intensity for different pumping wave frequencies, different magnetic field profiles, and single-gas/gas-mixing configurations was carried out. The results reveal a surprisingly very good agreement between warm-electron density fluctuations, output beam currents, and the calculated electromagnetic modal density of the plasma chamber. A charge-coupled device camera coupled to a small pin-hole allowing X-ray imaging was installed and numerous X-ray photos were taken in order to study the peculiarities of the ECRIS plasma structure.

  4. XIPE, the X-ray imaging polarimetry explorer: Opening a new window in the X-ray sky

    Science.gov (United States)

    Soffitta, Paolo; XIPE Collaboration

    2017-11-01

    XIPE, the X-ray Imaging Polarimetry Explorer, is a candidate ESA fourth medium size mission, now in competitive phase A, aimed at time-spectrally-spatially-resolved X-ray polarimetry of a large number of celestial sources as a breakthrough in high energy astrophysics and fundamental physics. Its payload consists of three X-ray optics with a total effective area larger than one XMM mirror but with a low mass and of three Gas Pixel Detectors at their focus. The focal length is 4 m and the whole satellite fits within the fairing of the Vega launcher without the need of an extendable bench. XIPE will be an observatory with 75% of the time devoted to a competitive guest observer program. Its consortium across Europe comprises Italy, Germany, Spain, United Kingdom, Switzerland, Poland, Sweden Until today, thanks to a dedicated experiment that dates back to the '70, only the Crab Nebula showed a non-zero polarization with large significance [1] in X-rays. XIPE, with its innovative detector, promises to make significative measurements on hundreds of celestial sources.

  5. Low-Dose X-ray CT Reconstruction via Dictionary Learning

    Science.gov (United States)

    Xu, Qiong; Zhang, Lei; Hsieh, Jiang; Wang, Ge

    2013-01-01

    Although diagnostic medical imaging provides enormous benefits in the early detection and accuracy diagnosis of various diseases, there are growing concerns on the potential side effect of radiation induced genetic, cancerous and other diseases. How to reduce radiation dose while maintaining the diagnostic performance is a major challenge in the computed tomography (CT) field. Inspired by the compressive sensing theory, the sparse constraint in terms of total variation (TV) minimization has already led to promising results for low-dose CT reconstruction. Compared to the discrete gradient transform used in the TV method, dictionary learning is proven to be an effective way for sparse representation. On the other hand, it is important to consider the statistical property of projection data in the low-dose CT case. Recently, we have developed a dictionary learning based approach for low-dose X-ray CT. In this paper, we present this method in detail and evaluate it in experiments. In our method, the sparse constraint in terms of a redundant dictionary is incorporated into an objective function in a statistical iterative reconstruction framework. The dictionary can be either predetermined before an image reconstruction task or adaptively defined during the reconstruction process. An alternating minimization scheme is developed to minimize the objective function. Our approach is evaluated with low-dose X-ray projections collected in animal and human CT studies, and the improvement associated with dictionary learning is quantified relative to filtered backprojection and TV-based reconstructions. The results show that the proposed approach might produce better images with lower noise and more detailed structural features in our selected cases. However, there is no proof that this is true for all kinds of structures. PMID:22542666

  6. Low-dose X-ray CT reconstruction via dictionary learning.

    Science.gov (United States)

    Xu, Qiong; Yu, Hengyong; Mou, Xuanqin; Zhang, Lei; Hsieh, Jiang; Wang, Ge

    2012-09-01

    Although diagnostic medical imaging provides enormous benefits in the early detection and accuracy diagnosis of various diseases, there are growing concerns on the potential side effect of radiation induced genetic, cancerous and other diseases. How to reduce radiation dose while maintaining the diagnostic performance is a major challenge in the computed tomography (CT) field. Inspired by the compressive sensing theory, the sparse constraint in terms of total variation (TV) minimization has already led to promising results for low-dose CT reconstruction. Compared to the discrete gradient transform used in the TV method, dictionary learning is proven to be an effective way for sparse representation. On the other hand, it is important to consider the statistical property of projection data in the low-dose CT case. Recently, we have developed a dictionary learning based approach for low-dose X-ray CT. In this paper, we present this method in detail and evaluate it in experiments. In our method, the sparse constraint in terms of a redundant dictionary is incorporated into an objective function in a statistical iterative reconstruction framework. The dictionary can be either predetermined before an image reconstruction task or adaptively defined during the reconstruction process. An alternating minimization scheme is developed to minimize the objective function. Our approach is evaluated with low-dose X-ray projections collected in animal and human CT studies, and the improvement associated with dictionary learning is quantified relative to filtered backprojection and TV-based reconstructions. The results show that the proposed approach might produce better images with lower noise and more detailed structural features in our selected cases. However, there is no proof that this is true for all kinds of structures.

  7. [Examination of patient dose reduction in cardiovasucular X-ray systems with a metal filter].

    Science.gov (United States)

    Yasuda, Mitsuyoshi; Kato, Kyouichi; Tanabe, Nobuaki; Sakiyama, Koushi; Uchiyama, Yushi; Suzuki, Yoshiaki; Suzuki, Hiroshi; Nakazawa, Yasuo

    2012-01-01

    In interventional X-ray for cardiology of flat panel digital detector (FPD), the phenomenon that exposure dose was suddenly increased when a subject thickness was thickened was recognized. At that time, variable metal built-in filters in FPD were all off. Therefore, we examined whether dose reduction was possible without affecting a clinical image using metal filter (filter) which we have been conventionally using for dose reduction. About 45% dose reduction was achieved when we measured an exposure dose at 30 cm of acrylic thickness in the presence of a filter. In addition, we measured signal to noise ratio/contrast to noise ratio/a resolution limit by the visual evaluation, and there was no influence by filter usage. In the clinical examination, visual evaluation of image quality of coronary angiography (40 cases) using a 5-point evaluation scale by a physician was performed. As a result, filter usage did not influence the image quality (p=NS). Therefore, reduction of sudden increase of exposure dose was achieved without influencing an image quality by adding filter to FPD.

  8. Software for X-Ray Images Calculation of Hydrogen Compression Device in Megabar Pressure Range

    Science.gov (United States)

    Egorov, Nikolay; Bykov, Alexander; Pavlov, Valery

    2007-06-01

    Software for x-ray images simulation is described. The software is a part of x-ray method used for investigation of an equation of state of hydrogen in a megabar pressure range. A graphical interface that clearly and simply allows users to input data for x-ray image calculation: properties of the studied device, parameters of the x-ray radiation source, parameters of the x-ray radiation recorder, the experiment geometry; to represent the calculation results and efficiently transmit them to other software for processing. The calculation time is minimized. This makes it possible to perform calculations in a dialogue regime. The software is written in ``MATLAB'' system.

  9. Two-energy twin image removal in atomic-resolution x-ray holography

    International Nuclear Information System (INIS)

    Nishino, Y.; Ishikawa, T.; Hayashi, K.; Takahashi, Y.; Matsubara, E.

    2002-01-01

    We propose a two-energy twin image removal algorithm for atomic-resolution x-ray holography. The validity of the algorithm is shown in a theoretical simulation and in an experiment of internal detector x-ray holography using a ZnSe single crystal. The algorithm, compared to the widely used multiple-energy algorithm, allows efficient measurement of holograms, and is especially important when the available x-ray energies are fixed. It enables twin image free holography using characteristic x rays from laboratory generators and x-ray pulses of free-electron lasers

  10. Evaluation of dose to tooth enamel from medical diagnostic X-ray examinations at Mayak PA

    Energy Technology Data Exchange (ETDEWEB)

    Wieser, A., E-mail: wieser@helmholtz-muenchen.de [Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, Institute of Radiation Protection, D-85764 Neuherberg (Germany); Vasilenko, E. [Mayak Production Association, 456780 Ozyorsk (Russian Federation); Zankl, M.; Greiter, M.; Ulanovsky, A. [Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, Institute of Radiation Protection, D-85764 Neuherberg (Germany); Sabayev, A.; Knyazev, V.; Zahrov, P. [Mayak Production Association, 456780 Ozyorsk (Russian Federation)

    2011-09-15

    The nuclear workers of the Mayak Production Association had regular check-ups including medical diagnostic X-ray examinations since start of the production lines in 1948. Doses from diagnostic examinations need to be considered in reconstruction of occupational doses of the workers with electron paramagnetic resonance (EPR) of tooth enamel. The numbers and types of examinations of an individual worker can be assessed from the Mayak PA archives but no information was available on doses delivered to teeth by a single specific examination. Of the twenty one applied examination procedures only three affected the teeth, these being X-ray examinations of teeth, skull and cervical spine. For these three kinds of examinations operational procedures and operating modes of X-ray units were compiled from the archive and photon spectra were obtained from a catalog of spectral data for diagnostic X-rays. Entrance doses in air kerma were calculated using the fluence of photon spectra and absorbed dose in tooth enamel for various tooth positions and exposure geometry was then calculated using dose conversion coefficients obtained from Monte Carlo simulations. Doses were calculated for examinations in 1948-2000. Except for examination of the skull, absorbed doses in enamel of incisors were found to be about twice as large as in enamel of molars. In the period before 1970 the largest mean absorbed doses in tooth enamel were due to X-ray examination of teeth, with 64 mGy and 34 mGy calculated for incisors and molars, respectively. In the same period the lowest mean doses were due to X-ray examination of the skull, with 11 mGy and 12 mGy calculated for incisors and molars, respectively. In the period from 1970 to 2000, largest mean doses in enamel were due to X-ray examination of cervical spine, with 23 mGy and 12 mGy calculated for incisors and molars, respectively.

  11. Estimation of effective dose from limited cone beam X-ray CT examination

    Energy Technology Data Exchange (ETDEWEB)

    Iwai, Kazuo; Arai, Yoshinori; Hashimoto, Koji [Nihon Univ., Tokyo (Japan). School of Dentistry; Nishizawa, Kanae

    2000-12-01

    The limited cone beam X-ray CT (Ortho-CT) was developed on the basis of multi-functional panoramic apparatus, SCANORA (Soredex Co. Helsinki Finland). The imaging intensifier (I.I.) was built in this apparatus as a X-ray detection device instead of X-ray film. The signal provided from I.I. was converted from analog into digital by an analog-digital converter and image reconstitution was done as a three-directional image of the dimensions 3.8 cm of width, 3.0 cm height and 3.8 cm depth with the personal computer. The 3DX Multi image micro CT'' (3DX) was developed along similar lines by MORITA Co., Ltd. (Kyoto, JAPAN). In this study, the stochastic effect on organ and tissue caused by examinations using Ortho-CT and 3DX was measured. The effective dose was estimated according to the recommendation of ICRP60 and was compared with those of panoramic radiography and computed tomography. The irradiation conditions were as follows: 85 kV, 10 mA with the filtration of 3 mmAl and added 1 mmCu for Ortho-CT, and 80 kV, 2 mA and the filtration of 3.1 mmAL for 3DX. The measurement of organ and tissue dose was performed using an anthropomorphic Rando woman phantom (Alderson Research Laboratories Co., Stanfora, CN), as well as by using two different type of thermoluminescent dosimeter (TLD); Panasonic UD-170A (BeO) and UD-110S (CaSO{sub 4}: Tm). The UD-170A was for dose measurement of the inner useful X-ray beams, while the UD-110S was for outer beams. The measured organ and tissue were those recommended with ICRP60 (gonad, breast, bone marrow, lung, thyroid gland, esophagus, stomach, colon, liver, bladder, skin, brain, thymus, adrenal, kidney, spleen, pancrease, upper large intestine, uterus, eyes and major salivary gland). The imaging by Orhto-CT was made in the left maxillary 1st molar, left mandibular 1st molar and temporomandibular joint. 3DX measurement was made in the maxillary incisor region and middle ear regions other than the regions mentioned above. The skin

  12. Imaging plate, a new type of x-ray area detector

    International Nuclear Information System (INIS)

    Kamiya, Nobuo; Amemiya, Yoshiyuki; Miyahara, Junji.

    1986-01-01

    In respective fields of X-ray crystallography, for the purpose of the efficient collection of reciprocal space information, two-dimensional X-ray detectors such as multiwire proportional chambers and X-ray television sets have been used together with conventional X-ray films. X-ray films are characterized by uniform sensitivity and high positional resolution over a wide area, but the sensitivity is low, and the range of action and the linearity of the sensitivity is problematic. They require the development process, accordingly lack promptitude. The MWPCs and X-ray television sets are superior in the sensitivity, its linearity, the range of action and promptitude, but interior in the uniformity and resolution to the films. Imaging plate is a new X-ray area detector developed by Fuji Photo Film Co., Ltd., for digital X-ray medical image diagnosis. This detector is superior in all the above mentioned performances, and it seems very useful also for X-ray crystallography. In this paper, the system composed of an imaging plate and its reader is described, and the basic performance as an X-ray area detector and the results of having recorded the diffraction images of protein crystals as the example of applying it to X-ray crystallography are reported. The imaging plate is that the crystalline fluorescent powder of BaFBr doped with Eu 2+ ions is applied on plastic films. (Kako, I.)

  13. Diffraction enhanced kinetic depth X-ray imaging

    Science.gov (United States)

    Dicken, A.

    An increasing number of fields would benefit from a single analytical probe that can characterise bulk objects that vary in morphology and/or material composition. These fields include security screening, medicine and material science. In this study the X-ray region is shown to be an effective probe for the characterisation of materials. The most prominent analytical techniques that utilise X-radiation are reviewed. The study then focuses on methods of amalgamating the three dimensional power of kinetic depth X-ray (KDFX) imaging with the materials discrimination of angular dispersive X-ray diffraction (ADXRD), thus providing KDEX with a much needed material specific counterpart. A knowledge of the sample position is essential for the correct interpretation of diffraction signatures. Two different sensor geometries (i.e. circumferential and linear) that are able to collect end interpret multiple unknown material diffraction patterns and attribute them to their respective loci within an inspection volume are investigated. The circumferential and linear detector geometries are hypothesised, simulated and then tested in an experimental setting with the later demonstrating a greater ability at discerning between mixed diffraction patterns produced by differing materials. Factors known to confound the linear diffraction method such as sample thickness and radiation energy have been explored and quantified with a possible means of mitigation being identified (i.e. via increasing the sample to detector distance). A series of diffraction patterns (following the linear diffraction approach) were obtained from a single phantom object that was simultaneously interrogated via KDEX imaging. Areas containing diffraction signatures matched from a threat library have been highlighted in the KDEX imagery via colour encoding and match index is inferred by intensity. This union is the first example of its kind and is called diffraction enhanced KDEX imagery. Finally an additional

  14. XIPE the X-Ray Imaging Polarimetry Explorer

    Science.gov (United States)

    Soffitta, Paolo; Barcons, Xavier; Bellazzini, Ronaldo; Braga, Joao; Costa, Enrico; Fraser, George W.; Gburek, Szymon; Huovelin, Juhani; Matt, Giorgio; Pearce, Mark; hide

    2013-01-01

    X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and temporal variability measurements and to imaging, allows a wealth of physical phenomena in astrophysics to be studied. X-ray polarimetry investigates the acceleration process, for example, including those typical of magnetic reconnection in solar flares, but also emission in the strong magnetic fields of neutron stars and white dwarfs. It detects scattering in asymmetric structures such as accretion disks and columns, and in the so-called molecular torus and ionization cones. In addition, it allows fundamental physics in regimes of gravity and of magnetic field intensity not accessible to experiments on the Earth to be probed. Finally, models that describe fundamental interactions (e.g. quantum gravity and the extension of the Standard Model) can be tested. We describe in this paper the X-ray Imaging Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a small mission with a launch in 2017. The proposal was, unfortunately, not selected. To be compliant with this schedule, we designed the payload mostly with existing items. The XIPE proposal takes advantage of the completed phase A of POLARIX for an ASI small mission program that was cancelled, but is different in many aspects: the detectors, the presence of a solar flare polarimeter and photometer and the use of a light platform derived by a mass production for a cluster of satellites. XIPE is composed of two out of the three existing JET-X telescopes with two Gas Pixel Detectors (GPD) filled with a He-DME mixture at their focus. Two additional GPDs filled with a 3-bar Ar-DME mixture always face the Sun to detect polarization from solar flares. The Minimum Detectable Polarization of a 1 mCrab source reaches 14 in the 210 keV band in 105 s for pointed observations, and 0.6 for an X10 class solar flare in the 1535 keV energy band. The imaging capability is 24 arcsec Half Energy Width (HEW) in a Field of View of 14

  15. X-ray imaging and spectroscopic measurements of implosions

    International Nuclear Information System (INIS)

    Hammel, B.A.; Ress, D.R.; Keane, C.J.; Kilkenny, J.D.; Landen, O.L.; Bell, P.; Pasha, R.; Wallace, R.J.; Bradley, D.K.

    1992-01-01

    Time-resolved x-ray measurements are essential in the investigation of laser-driven inertial confinement fusion, where neutron and x-ray emission are the only observable signatures of the compressed core conditions. High-speed detectors, available for x-ray measurement, provide a means of measuring the rapidly evolving conditions in imploding capsules on picosecond time scales. We address a wide range of issues in our indirectly driven implosion experiments on Nova, with a large variety of x-ray measurement techniques. Critical issues include symmetry of the compressed core, fuel density and temperature and hydrodynamic mix at the pusher/fuel interface

  16. The Advanced X-ray Spectroscopy and Imaging Observatory (AXSIO)

    Science.gov (United States)

    White, Nicholas E.; Bookbinder, Jay; Petre, Robert; Smith, Randall; Ptak, Andrew; Tananbaum, Harvey; Garcia, Michael

    2012-01-01

    Following recommendations from the 2010 "New Worlds, New Horizons" (NWNH) report, the Advanced X-ray Spectroscopy and Imaging Observatory (AXSIO) concept streamlines the International X-ray Observatory (IXO) mission to concentrate on the science objectives that are enabled by high-resolution spectroscopic capabilities. AXSIO will trace orbits close to the event horizon of black holes, measure black hole spin for tens of supermassive black holes (SMBH), use spectroscopy to characterize outflows and the environment of AGN during their peak activity, observe 5MBH out to redshift z=6, map bulk motions and turbulence in galaxy clusters, find the missing baryons in the cosmic web using background quasars, and observe the process of cosmic feedback where black holes and supernovae inject energy on galactic and intergalactic scales. These measurements are enabled by a 0.9 sq m collecting area at 1.25 keV, a micro calorimeter array providing high-resolution spectroscopic imaging and a deployable high efficiency grating spectrometer. AXSIO delivers a 30-fold increase in effective area for high resolution spectroscopy. The key simplifications are guided by recommendations in the NWNH panel report include a reduction in focal length from 20m to 10m, eliminating the extendable optical bench, and a reduction in the instrument complement from six to two, avoiding a movable instrument platform. A focus on spectroscopic science allows the spatial resolution requirement to be relaxed to 10 arc sec (with a 5 arc sec goal). These simplifications decrease the total mission cost to under the $2B cost to NASA recommended by NWNH. AXSIO will be available to the entire astronomical community with observing allocations based on peer-review.

  17. An autonomous CZT module for X-ray diffraction imaging

    International Nuclear Information System (INIS)

    Montemont, G.; Monnet, O.; Stanchina, S.; Verger, L.; Kosciesza, D.; Schlomka, J.P.

    2013-01-01

    We present the development of a CZT-based detection module dedicated to X-ray diffraction imaging. This kind of application requires a good energy and spatial resolution in order to resolve Bragg peaks. In a first part, we present the detector configuration used and dimensioning constraints. As the input energy range is comprised between 20 and 150 keV, we use 5 mm thick high resistivity CZT crystals. The 660 mm 2 detection area is segmented on both sides into 192 anodes and 12 cathodes. Signals from both sides are read jointly in order to perform multi parametric event corrections (depth of interaction, charge sharing, induction sharing). In order to be integrated easily inside an X-ray imaging system, the system has been conceived to be completely autonomous: it is powered by a single 12 V supply and is interfaced with the external system by Ethernet for communication and RS485 for synchronization. In a second part, we describe the system readout architecture and then the implementation of the data processing. An FPGA circuit embeds a digital processing chain that carries out readout ASIC interfacing and advanced multi parametric data corrections. Gain, offset but also depth of interaction and charge sharing are corrected on the flow. Incoming events from different channels are clustered together by comparing their location and time of occurrence. The FPGA also embeds a processor running an operating system that controls the system, carries out all calibrations, automated tests and acquisitions. Eventually, we show the results obtained and demonstrate the relative influence of depth of interaction and charge sharing. Homogeneity of detector behavior is also discussed and the reproducibility of the performance between modules is presented. The average energy resolution at 25 C is 2.4 % FWHM at 122 keV and 3.8 % FWHM at 60 keV and the average efficiency is 73 %. (authors)

  18. An investigation of dose changes for therapeutic kilovoltage x-ray beams with underlying lead shielding

    International Nuclear Information System (INIS)

    Hill, Robin; Healy, Brendan; Holloway, Lois; Baldock, Clive

    2007-01-01

    Kilovoltage x-ray beams are used to treat cancer on or close to the skin surface. Many clinical cases use high atomic number materials as shielding to reduce dose to underlying healthy tissues. In this work, we have investigated the effect on both the surface dose and depth doses in a water phantom with lead shielding at depth in the phantom. The EGSnrc Monte Carlo code was used to simulate the water phantom and to calculate the surface doses and depth doses using primary x-ray beam spectra derived from an analytical model. The x-ray beams were in the energy range of 75-135 kVp with field sizes of 2, 5 and 8 cm diameter. The lead sheet was located beneath the water surface at depths ranging from 0.5-7.5 cm. The surface dose decreased as the lead was positioned closer to the water surface and as the field size was increased. The variation in surface dose as a function of x-ray beam energy was only small but the maximum reduction occurred for the 100 kVp x-ray beam. For the 8 cm diameter field with the lead at 1 cm depth and using the 100 kVp x-ray beam, the surface dose was reduced to 0.898 of the surface dose in the water phantom only. Measured surface dose changes, using a Farmer-type ionization chamber, agreed with the Monte Carlo calculated doses. Calculated depth doses in water with a lead sheet positioned below the surface showed that the dose fall-off increased as the lead was positioned closer to the water surface as compared to the depth dose in the water phantom only. Monte Carlo calculations of the total x-ray beam spectrum at the water surface showed that the total fluence decreased due to a reduction in backscatter from within the water and very little backscatter from the lead. The mean energy of the x-ray spectrum varied less than 1 keV, with the lead at 1 cm beneath the water phantom surface. As the Monte Carlo calculations showed good agreement with the measured results, this method can be used to verify surface dose changes in clinical situations

  19. The reduction methods of operator's radiation dose for portable dental X-ray machines.

    Science.gov (United States)

    Cho, Jeong-Yeon; Han, Won-Jeong

    2012-08-01

    This study was aimed to investigate the methods to reduce operator's radiation dose when taking intraoral radiographs with portable dental X-ray machines. Two kinds of portable dental X-ray machines (DX3000, Dexcowin and Rextar, Posdion) were used. Operator's radiation dose was measured with an 1,800 cc ionization chamber (RadCal Corp.) at the hand level of X-ray tubehead and at the operator's chest and waist levels with and without the backscatter shield. The operator's radiation dose at the hand level was measured with and without lead gloves and with long and short cones. The backscatter shield reduced operator's radiation dose at the hand level of X-ray tubehead to 23 - 32%, the lead gloves to 26 - 31%, and long cone to 48 - 52%. And the backscatter shield reduced operator's radiation dose at the operator's chest and waist levels to 0.1 - 37%. When portable dental X-ray systems are used, it is recommended to select X-ray machine attached with a backscatter shield and a long cone and to wear the lead gloves.

  20. Energy spectrum analysis between single and dual energy source x-ray imaging for PCB non-destructive test

    International Nuclear Information System (INIS)

    Park, Kyeong Jin; Kim, Myung Soo; Lee, Min Ju; Kang, Dong Uk; Lee, Dae Hee; Kim, Ye Won; Kim, Chan Kyu; Kim, Hyoung Taek; Kim, Gi Yoon; Cho, Gyu Seong

    2015-01-01

    Reliability of printed circuit board (PCB), which is based on high integrated circuit technology, is having been important because of development of electric and self-driving car. In order to answer these demand, automated X-ray inspection (AXI) is best solution for PCB nondestructive test. PCB is consist of plastic, copper, and, lead, which have low to high Z-number materials. By using dual energy X-ray imaging, these materials can be inspected accurately and efficiently. Dual energy X-ray imaging, that have the advantage of separating materials, however, need some solution such as energy separation method and enhancing efficiency because PCB has materials that has wide range of Z-number. In this work, we found out several things by analysis of X-ray energy spectrum. Separating between lead and combination of plastic and copper is only possible with energy range not dose. On the other hand, separating between plastic and copper is only with dose not energy range. Moreover the copper filter of high energy part of dual X-ray imaging and 50 kVp of low energy part of dual X-ray imaging is best for efficiency

  1. Energy spectrum analysis between single and dual energy source x-ray imaging for PCB non-destructive test

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyeong Jin; Kim, Myung Soo; Lee, Min Ju; Kang, Dong Uk; Lee, Dae Hee; Kim, Ye Won; Kim, Chan Kyu; Kim, Hyoung Taek; Kim, Gi Yoon; Cho, Gyu Seong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-08-15

    Reliability of printed circuit board (PCB), which is based on high integrated circuit technology, is having been important because of development of electric and self-driving car. In order to answer these demand, automated X-ray inspection (AXI) is best solution for PCB nondestructive test. PCB is consist of plastic, copper, and, lead, which have low to high Z-number materials. By using dual energy X-ray imaging, these materials can be inspected accurately and efficiently. Dual energy X-ray imaging, that have the advantage of separating materials, however, need some solution such as energy separation method and enhancing efficiency because PCB has materials that has wide range of Z-number. In this work, we found out several things by analysis of X-ray energy spectrum. Separating between lead and combination of plastic and copper is only possible with energy range not dose. On the other hand, separating between plastic and copper is only with dose not energy range. Moreover the copper filter of high energy part of dual X-ray imaging and 50 kVp of low energy part of dual X-ray imaging is best for efficiency.

  2. Correction method and software for image distortion and nonuniform response in charge-coupled device-based x-ray detectors utilizing x-ray image intensifier

    International Nuclear Information System (INIS)

    Ito, Kazuki; Kamikubo, Hironari; Yagi, Naoto; Amemiya, Yoshiyuki

    2005-01-01

    An on-site method of correcting the image distortion and nonuniform response of a charge-coupled device (CCD)-based X-ray detector was developed using the response of the imaging plate as a reference. The CCD-based X-ray detector consists of a beryllium-windowed X-ray image intensifier (Be-XRII) and a CCD as the image sensor. An image distortion of 29% was improved to less than 1% after the correction. In the correction of nonuniform response due to image distortion, subpixel approximation was performed for the redistribution of pixel values. The optimal number of subpixels was also discussed. In an experiment with polystyrene (PS) latex, it was verified that the correction of both image distortion and nonuniform response worked properly. The correction for the 'contrast reduction' problem was also demonstrated for an isotropic X-ray scattering pattern from the PS latex. (author)

  3. Evaluation of image quality when using grid during child chest x-ray examination

    Energy Technology Data Exchange (ETDEWEB)

    Jeung Seung Hun [Dept. of Radiology, SeoSan JungAng General Hospital, Seosan (Korea, Republic of); Han, Beom Hul [Dept. of Radiological Science, SeoNam University, Gwangju (Korea, Republic of); Jung, Hong Ryang [Dept. of Radiological Science, Hanseo University, (Korea, Republic of)

    2017-09-15

    Since in case of children, they are sensitive to the radiation compared to the adult and the potential exposure damage lasts longer, the exposure dose should be managed better than for the adult. Therefore, this study was conducted to observe the change in the chest x-ray image by the use of grid, which eliminates the scattering rays but increases the exposure dose during the child chest x-ray examination. As a research method, SNR, CNR and V. Vuichi were measured at 100 cm and 180 cm with the grid varying the kVp to 70, 90 and 110. In addition, SNR, CNR and V. Vuichi were measured fixing 100 cm and 180cm without grid and varying the dose to 6, 8 and 10 mAs. In the results of measuring them by fixing kVp, SNR, VNR and V. Vuichi were represented high when FID is 100cm. And in the results of meaduring them varying mAs, SNR, VNR and V. Vuichi were represented high when FID is 100cm. Currently in our country, the chest x-ray examination is performed at 180 cm. However, as the image is measured high when FID is 100 cm, in case of child, FID is deemed to be 100 cm.

  4. Evaluation of image quality when using grid during child chest x-ray examination

    International Nuclear Information System (INIS)

    Jeung Seung Hun; Han, Beom Hul; Jung, Hong Ryang

    2017-01-01

    Since in case of children, they are sensitive to the radiation compared to the adult and the potential exposure damage lasts longer, the exposure dose should be managed better than for the adult. Therefore, this study was conducted to observe the change in the chest x-ray image by the use of grid, which eliminates the scattering rays but increases the exposure dose during the child chest x-ray examination. As a research method, SNR, CNR and V. Vuichi were measured at 100 cm and 180 cm with the grid varying the kVp to 70, 90 and 110. In addition, SNR, CNR and V. Vuichi were measured fixing 100 cm and 180cm without grid and varying the dose to 6, 8 and 10 mAs. In the results of measuring them by fixing kVp, SNR, VNR and V. Vuichi were represented high when FID is 100cm. And in the results of meaduring them varying mAs, SNR, VNR and V. Vuichi were represented high when FID is 100cm. Currently in our country, the chest x-ray examination is performed at 180 cm. However, as the image is measured high when FID is 100 cm, in case of child, FID is deemed to be 100 cm

  5. Investigation of the hard x-ray background in backlit pinhole imagers

    Energy Technology Data Exchange (ETDEWEB)

    Fein, J. R., E-mail: jrfein@umich.edu; Holloway, J. P. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States); Peebles, J. L. [Center for Energy Research, University of California, San Diego, La Jolla, California 92093 (United States); Keiter, P. A.; Klein, S. R.; Kuranz, C. C.; Manuel, M. J.-E.; Drake, R. P. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States)

    2014-11-15

    Hard x-rays from laser-produced hot electrons (>10 keV) in backlit pinhole imagers can give rise to a background signal that decreases signal dynamic range in radiographs. Consequently, significant uncertainties are introduced to the measured optical depth of imaged plasmas. Past experiments have demonstrated that hard x-rays are produced when hot electrons interact with the high-Z pinhole substrate used to collimate the softer He-α x-ray source. Results are presented from recent experiments performed on the OMEGA-60 laser to further study the production of hard x-rays in the pinhole substrate and how these x-rays contribute to the background signal in radiographs. Radiographic image plates measured hard x-rays from pinhole imagers with Mo, Sn, and Ta pinhole substrates. The variation in background signal between pinhole substrates provides evidence that much of this background comes from x-rays produced in the pinhole substrate itself. A Monte Carlo electron transport code was used to model x-ray production from hot electrons interacting in the pinhole substrate, as well as to model measurements of x-rays from the irradiated side of the targets, recorded by a bremsstrahlung x-ray spectrometer. Inconsistencies in inferred hot electron distributions between the different pinhole substrate materials demonstrate that additional sources of hot electrons beyond those modeled may produce hard x-rays in the pinhole substrate.

  6. X-ray performance of a wafer-scale CMOS flat panel imager for applications in medical imaging and nondestructive testing

    International Nuclear Information System (INIS)

    Cha, Bo Kyung; Jeon, Seongchae; Seo, Chang-Woo

    2016-01-01

    This paper presents a wafer-scale complementary metal-oxide semiconductor (CMOS)-based X-ray flat panel detector for medical imaging and nondestructive testing applications. In this study, our proposed X-ray CMOS flat panel imager has been fabricated by using a 0.35 µm 1-poly/4-metal CMOS process. The pixel size is 100 µm×100 µm and the pixel array format is 1200×1200 pixels, which provide a field-of-view (FOV) of 120mm×120 mm. The 14.3-bit extended counting analog-to digital converter (ADC) with built-in binning mode was used to reduce the area and simultaneously improve the image resolution. The different screens such as thallium-doped CsI (CsI:Tl) and terbium gadolinium oxysulfide (Gd_2O_2S:Tb) scintillators were used as conversion materials for X-rays to visible light photons. The X-ray imaging performance such as X-ray sensitivity as a function of X-ray exposure dose, spatial resolution, image lag and X-ray images of various objects were measured under practical medical and industrial application conditions. This paper results demonstrate that our prototype CMOS-based X-ray flat panel imager has the significant potential for medical imaging and non-destructive testing (NDT) applications with high-resolution and high speed rate.

  7. X-ray performance of a wafer-scale CMOS flat panel imager for applications in medical imaging and nondestructive testing

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Bo Kyung, E-mail: goldrain99@kaist.ac.kr [Advanced Medical Device Research Center, Korea Electrotechnology Research Institute, Ansan (Korea, Republic of); Jeon, Seongchae [Advanced Medical Device Research Center, Korea Electrotechnology Research Institute, Ansan (Korea, Republic of); Seo, Chang-Woo [Department of Radiological Science, Yonsei University, Gangwon-do 220-710 (Korea, Republic of)

    2016-09-21

    This paper presents a wafer-scale complementary metal-oxide semiconductor (CMOS)-based X-ray flat panel detector for medical imaging and nondestructive testing applications. In this study, our proposed X-ray CMOS flat panel imager has been fabricated by using a 0.35 µm 1-poly/4-metal CMOS process. The pixel size is 100 µm×100 µm and the pixel array format is 1200×1200 pixels, which provide a field-of-view (FOV) of 120mm×120 mm. The 14.3-bit extended counting analog-to digital converter (ADC) with built-in binning mode was used to reduce the area and simultaneously improve the image resolution. The different screens such as thallium-doped CsI (CsI:Tl) and terbium gadolinium oxysulfide (Gd{sub 2}O{sub 2}S:Tb) scintillators were used as conversion materials for X-rays to visible light photons. The X-ray imaging performance such as X-ray sensitivity as a function of X-ray exposure dose, spatial resolution, image lag and X-ray images of various objects were measured under practical medical and industrial application conditions. This paper results demonstrate that our prototype CMOS-based X-ray flat panel imager has the significant potential for medical imaging and non-destructive testing (NDT) applications with high-resolution and high speed rate.

  8. X-ray volumetric imaging in image-guided radiotherapy: The new standard in on-treatment imaging

    International Nuclear Information System (INIS)

    McBain, Catherine A.; Henry, Ann M.; Sykes, Jonathan; Amer, Ali; Marchant, Tom; Moore, Christopher M.; Davies, Julie; Stratford, Julia; McCarthy, Claire; Porritt, Bridget; Williams, Peter; Khoo, Vincent S.; Price, Pat

    2006-01-01

    Purpose: X-ray volumetric imaging (XVI) for the first time allows for the on-treatment acquisition of three-dimensional (3D) kV cone beam computed tomography (CT) images. Clinical imaging using the Synergy System (Elekta, Crawley, UK) commenced in July 2003. This study evaluated image quality and dose delivered and assessed clinical utility for treatment verification at a range of anatomic sites. Methods and Materials: Single XVIs were acquired from 30 patients undergoing radiotherapy for tumors at 10 different anatomic sites. Patients were imaged in their setup position. Radiation doses received were measured using TLDs on the skin surface. The utility of XVI in verifying target volume coverage was qualitatively assessed by experienced clinicians. Results: X-ray volumetric imaging acquisition was completed in the treatment position at all anatomic sites. At sites where a full gantry rotation was not possible, XVIs were reconstructed from projection images acquired from partial rotations. Soft-tissue definition of organ boundaries allowed direct assessment of 3D target volume coverage at all sites. Individual image quality depended on both imaging parameters and patient characteristics. Radiation dose ranged from 0.003 Gy in the head to 0.03 Gy in the pelvis. Conclusions: On-treatment XVI provided 3D verification images with soft-tissue definition at all anatomic sites at acceptably low radiation doses. This technology sets a new standard in treatment verification and will facilitate novel adaptive radiotherapy techniques

  9. Monte Carlo simulation of dose enhancement effect of X-ray at Au/Si interface

    International Nuclear Information System (INIS)

    Wu Zhengxin; He Chengfa; Lu Wu; Guo Qi; Yu Xin; Zhang Lei; Deng Wei; Zheng Qiwen; ARKIN Abulim

    2013-01-01

    Background: The dose enhancement factor of X-ray was found in 1970s, because of its bad damage to electronic devices. Purpose: This paper is mainly to calculate the dose-enhancement factor at Au/Si interfaces. Methods: The gradient distribution of dose with X-rays has been studied at and near the interface of Au/Si by Monte-Carlo simulation of particle transportation. The mechanism of dose enhancement is discussed based on the principles of interaction of photon with matter. A 3D Au/Si model has been established by MCNP5 program and the dose-enhancement factors of different thicknesses Au/Si interfaces were calculated by Monte Carlo method. Results: The calculated results demonstrate that there exists a stronger dose-enhancement in the Si side near the interface when the energy of X-ray is 30-300 keV. Conclusions: When the thickness of Au is 0-10 μm, dose-enhancement factor of X-ray increases along with the increase of the thickness of Au, when the thickness of Au exceeds 10 μm, dose-enhancement factor of X-ray decreases along with the increase of the thickness of Au. (authors)

  10. X-ray imaging device for one-dimensional and two-dimensional radioscopy

    International Nuclear Information System (INIS)

    1978-01-01

    The X-ray imaging device for the selectable one-dimensional or two-dimensional pictures of objects illuminated by X-rays, comprising an X-ray source, an X-ray screen, and an opto-electrical picture development device placed behind the screen, is characterized by an anamorphotic optical system, which is positioned with a one-dimensional illumination between the X-ray screen and the opto-electrical device and that a two-dimensional illumination will be developed, and that in view of the lens system which forms part of the opto-electrical device, there is placed an X-ray screen in a specified beam direction so that a magnified image may be formed by equalisation of the distance between the X-ray screen and the lens system. (G.C.)

  11. ASSESSMENT OF RESTORATION METHODS OF X-RAY IMAGES WITH EMPHASIS ON MEDICAL PHOTOGRAMMETRIC USAGE

    Directory of Open Access Journals (Sweden)

    S. Hosseinian

    2016-06-01

    Full Text Available Nowadays, various medical X-ray imaging methods such as digital radiography, computed tomography and fluoroscopy are used as important tools in diagnostic and operative processes especially in the computer and robotic assisted surgeries. The procedures of extracting information from these images require appropriate deblurring and denoising processes on the pre- and intra-operative images in order to obtain more accurate information. This issue becomes more considerable when the X-ray images are planned to be employed in the photogrammetric processes for 3D reconstruction from multi-view X-ray images since, accurate data should be extracted from images for 3D modelling and the quality of X-ray images affects directly on the results of the algorithms. For restoration of X-ray images, it is essential to consider the nature and characteristics of these kinds of images. X-ray images exhibit severe quantum noise due to limited X-ray photons involved. The assumptions of Gaussian modelling are not appropriate for photon-limited images such as X-ray images, because of the nature of signal-dependant quantum noise. These images are generally modelled by Poisson distribution which is the most common model for low-intensity imaging. In this paper, existing methods are evaluated. For this purpose, after demonstrating the properties of medical X-ray images, the more efficient and recommended methods for restoration of X-ray images would be described and assessed. After explaining these approaches, they are implemented on samples from different kinds of X-ray images. By considering the results, it is concluded that using PURE-LET, provides more effective and efficient denoising than other examined methods in this research.

  12. Development of a head simulator for exposure dose estimation on patients exposed by odontological X-rays

    International Nuclear Information System (INIS)

    Moura Neto, Francisco N.; Batista, Eutropio V.; Santos, Adriano M.

    2009-01-01

    In the obtaining a odontological radiography, the individual is exposed to te radiation and part of that radiation will be absorbed by his organism. The estimative of absorbed dose can be accomplished through calculations where are considered: the distance from the source to the individual, the energy of the emitted X-ray at the moment of the exposure and the bode region exposed; and as that option does not possess great precision, alternative forms are seek for the quantification such doses. This work proposes the construction of a head simulator to be used in the estimative of absorbed dose in patients, during the accomplishment of the odontological radiographic examinations. As a perspective of work, it is intended to use the phantom to help in the absorbed doses for obtainment of parameters in X-ray odontological devices, contributing of image obtainment with more quality and less radiation dose in the patient

  13. Patient's dose assessment during sinus X-rays radiography at 'Hopital du Point G'

    International Nuclear Information System (INIS)

    Sidibe, S.; Sacko, B.Y.; Doucoure, M.; Traore, B.; Traore, I.

    2001-01-01

    Objective: To evaluate the patient's X-rays dose during head radiography for sinusitis; To precise the influence of source-image distance on the patient's dose. Material and method: From May 1997 to January 1999, 83 patients with clinical suspicious sinusitis have been included in this study. Skull radiography in 3 positions (posterior, lateral and Blondeau view) have been achieved for each patient on 24x30 centimeters size films. These radiographies were realised on a Diagnost 7 Masio Philip X-rays machine. Three TLD dosimeters were pasted against every patient target organs (thyroid, right and left eyes). The source-image distance (SID) was 100 centimeters for the first group (35 patients) and 125 centimeters for the second group (48 patients). The selected parameters (high voltage and charge) were as follows: Skull postero-anterior view: 65 to 85 kV, 80 mAs; Skull lateral view: 60 to 75 kV, 80 mAs; Blondeau view (paranasal sinuses): 90 to 95 kV, 100 mAs. Results: All the radiographies were analysed by the same radiologist who didn't know the SID. All the films were of good quality. The patient's dose in millisievert for each target organ were: Group I (SID = 100 cm): Left eye 3,2 (+ ou - 0,66); Right eye 3, 0 (+ ou - 0,82); Thyroid 0,62 (+ ou - 0,09). Group II (SID = 125 cm): Left eye 1,9 (+ ou - 0,48); Right eye 1, 86 (+ ou - 0,50); Thyroid 0,39 (+ ou - 0,08). In conclusion, the increase of SID from 100 to 125 centimeters allows patient's dose reduction by a factor of 1.6 without the alteration of the films quality, hence the reliability of the diagnosis. (author)

  14. Organ or tissue doses, effective dose and collective effective dose from X-ray diagnosis, in Japan

    International Nuclear Information System (INIS)

    Murayama, Takashi; Nishizawa, Kanae; Noda, Yutaka; Kumamoto, Yoshikazu; Iwai, Kazuo.

    1996-01-01

    Effective doses and collective effective doses from X-ray diagnostic examinations were calculated on the basis of the frequency of examinations estimated by a nationwide survey and the organ or tissue doses experimentally determined. The average organ or tissue doses were determined with thermoluminescence dosimeters put at various sites of organs or tissues in an adult and a child phantom. Effective doses (effective dose equivalents) were calculated as the sum of the weighted equivalent doses in all the organs or tissues of the body. As the examples of results, the effective doses per radiographic examination were approximately 7 mGy for male, and 9 mGy for female angiocardiography, and about 3 mGy for barium meal. Annual collective effective dose from X-ray diagnostic examinations in 1986 were about 104 x 10 3 person Sv from radiography and 118 x 10 3 person Sv from fluoroscopy, with the total of 222 x 10 3 person Sv. (author)

  15. New opportunities for 3D materials science of polycrystalline materials at the micrometre lengthscale by combined use of X-ray diffraction and X-ray imaging

    DEFF Research Database (Denmark)

    Ludwig, W.; King, A.; Reischig, P.

    2009-01-01

    Non-destructive, three-dimensional (3D) characterization of the grain structure in mono-phase polycrystalline materials is an open challenge in material science. Recent advances in synchrotron based X-ray imaging and diffraction techniques offer interesting possibilities for mapping 3D grain shapes....... A recent extension of this methodology, termed X-ray diffraction contrast tomography (DCT), combines the principles of X-ray diffraction imaging, three-dimensional X-ray diffraction microscopy (3DXRD) and image reconstruction from projections. DCT provides simultaneous access to 3D grain shape...

  16. Photon Counting Energy Dispersive Detector Arrays for X-ray Imaging.

    Science.gov (United States)

    Iwanczyk, Jan S; Nygård, Einar; Meirav, Oded; Arenson, Jerry; Barber, William C; Hartsough, Neal E; Malakhov, Nail; Wessel, Jan C

    2009-01-01

    The development of an innovative detector technology for photon-counting in X-ray imaging is reported. This new generation of detectors, based on pixellated cadmium telluride (CdTe) and cadmium zinc telluride (CZT) detector arrays electrically connected to application specific integrated circuits (ASICs) for readout, will produce fast and highly efficient photon-counting and energy-dispersive X-ray imaging. There are a number of applications that can greatly benefit from these novel imagers including mammography, planar radiography, and computed tomography (CT). Systems based on this new detector technology can provide compositional analysis of tissue through spectroscopic X-ray imaging, significantly improve overall image quality, and may significantly reduce X-ray dose to the patient. A very high X-ray flux is utilized in many of these applications. For example, CT scanners can produce ~100 Mphotons/mm(2)/s in the unattenuated beam. High flux is required in order to collect sufficient photon statistics in the measurement of the transmitted flux (attenuated beam) during the very short time frame of a CT scan. This high count rate combined with a need for high detection efficiency requires the development of detector structures that can provide a response signal much faster than the transit time of carriers over the whole detector thickness. We have developed CdTe and CZT detector array structures which are 3 mm thick with 16×16 pixels and a 1 mm pixel pitch. These structures, in the two different implementations presented here, utilize either a small pixel effect or a drift phenomenon. An energy resolution of 4.75% at 122 keV has been obtained with a 30 ns peaking time using discrete electronics and a (57)Co source. An output rate of 6×10(6) counts per second per individual pixel has been obtained with our ASIC readout electronics and a clinical CT X-ray tube. Additionally, the first clinical CT images, taken with several of our prototype photon-counting and

  17. Future of X-ray phase imaging in medical imaging technology

    International Nuclear Information System (INIS)

    Momose, Atsushi

    2007-01-01

    Weakly absorbing materials, such as biological, soft tissues, can be imaged by generating contrast due to the phase shift of X-rays. In the past decade, several methods for X-ray phase imaging were proposed and demonstrated. The performance of X-ray phase imaging is attractive in the field of medical imaging technology, and its development for practical use is expected. Many methods, however, have been developed under the assumption of the use of synchrotron radiation, which is an obstacle to practical use. The method based on Talbot (-Lau) interferometry enables us to use a compact X-ray source, and its development is expected as a breakthrough for medical applications. (author)

  18. Characterization of Polycrystalline Materials Using Synchrotron X-ray Imaging and Diffraction Techniques

    DEFF Research Database (Denmark)

    Ludwig, Wolfgang; King, A.; Herbig, M.

    2010-01-01

    The combination of synchrotron radiation x-ray imaging and diffraction techniques offers new possibilities for in-situ observation of deformation and damage mechanisms in the bulk of polycrystalline materials. Minute changes in electron density (i.e., cracks, porosities) can be detected using...... propagation based phase contrast imaging, a 3-D imaging mode exploiting the coherence properties of third generation synchrotron beams. Furthermore, for some classes of polycrystalline materials, one may use a 3-D variant of x-ray diffraction imaging, termed x-ray diffraction contrast tomography. X-ray...

  19. Estimation of the population dose from medical X-ray diagnostic examination in Shandong province, China

    International Nuclear Information System (INIS)

    Su Xieming

    1985-01-01

    The exposure doses on the examinated body surface for verious types of X-ray diagnostic examanition in Shandong Province were surveyed. The collective effective dose equivalent in per million population were calculated with the measured results, the ratios of orga absorbed doses to irradiated surface exposure doses and the frequencies of X-ray examination in Shandong Province. The result was 326 man.Sv per million total population in 1980, of which chest fluoroscopies. lumbar spine radiographies and G.I. examination were estimated to be about 78, 9 and 5 precent, respectively

  20. Relationship between x-ray illumination field size and flat field intensity and its impacts on x-ray imaging

    International Nuclear Information System (INIS)

    Dong Xue; Niu Tianye; Jia Xun; Zhu Lei

    2012-01-01

    Purpose: X-ray cone-beam CT (CBCT) is being increasingly used for various clinical applications, while its performance is still hindered by image artifacts. This work investigates a new source of reconstruction error, which is often overlooked in the current CBCT imaging. The authors find that the x-ray flat field intensity (I 0 ) varies significantly as the illumination volume size changes at different collimator settings. A wrong I 0 value leads to inaccurate CT numbers of reconstructed images as well as wrong scatter measurements in the CBCT research. Methods: The authors argue that the finite size of x-ray focal spot together with the detector glare effect cause the I 0 variation at different illumination sizes. Although the focal spot of commercial x-ray tubes typically has a nominal size of less than 1 mm, the off-focal-spot radiation covers an area of several millimeters on the tungsten target. Due to the large magnification factor from the field collimator to the detector, the penumbra effects of the collimator blades result in different I 0 values for different illumination field sizes. Detector glare further increases the variation, since one pencil beam of incident x-ray is scattered into an area of several centimeters on the detector. In this paper, the authors study these two effects by measuring the focal spot distribution with a pinhole assembly and the detector point spread function (PSF) with an edge-spread function method. The authors then derive a formula to estimate the I 0 value for different illumination field sizes, using the measured focal spot distribution and the detector PSF. Phantom studies are carried out to investigate the accuracy of scatter measurements and CT images with and without considering the I 0 variation effects. Results: On our tabletop system with a Varian Paxscan 4030CB flat-panel detector and a Varian RAD-94 x-ray tube as used on a clinical CBCT system, the focal spot distribution has a measured full

  1. Gas scintillation glass GEM detector for high-resolution X-ray imaging and CT

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, T., E-mail: fujiwara-t@aist.go.jp [Research Institute for Measurement and Analytical Instrumentation, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Mitsuya, Y. [Nuclear Professional School, The University of Tokyo, Tokai, Naka, Ibaraki 319-1188 (Japan); Fushie, T. [Radiment Lab. Inc., Setagaya, Tokyo 156-0044 (Japan); Murata, K.; Kawamura, A.; Koishikawa, A. [XIT Co., Naruse, Machida, Tokyo 194-0045 (Japan); Toyokawa, H. [Research Institute for Measurement and Analytical Instrumentation, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Takahashi, H. [Institute of Engineering Innovation, School of Engineering, The University of Tokyo, Bunkyo, Tokyo 113-8654 (Japan)

    2017-04-01

    A high-spatial-resolution X-ray-imaging gaseous detector has been developed with a single high-gas-gain glass gas electron multiplier (G-GEM), scintillation gas, and optical camera. High-resolution X-ray imaging of soft elements is performed with a spatial resolution of 281 µm rms and an effective area of 100×100 mm. In addition, high-resolution X-ray 3D computed tomography (CT) is successfully demonstrated with the gaseous detector. It shows high sensitivity to low-energy X-rays, which results in high-contrast radiographs of objects containing elements with low atomic numbers. In addition, the high yield of scintillation light enables fast X-ray imaging, which is an advantage for constructing CT images with low-energy X-rays.

  2. Iterative reconstruction for x-ray computed tomography using prior-image induced nonlocal regularization.

    Science.gov (United States)

    Zhang, Hua; Huang, Jing; Ma, Jianhua; Bian, Zhaoying; Feng, Qianjin; Lu, Hongbing; Liang, Zhengrong; Chen, Wufan

    2014-09-01

    Repeated X-ray computed tomography (CT) scans are often required in several specific applications such as perfusion imaging, image-guided biopsy needle, image-guided intervention, and radiotherapy with noticeable benefits. However, the associated cumulative radiation dose significantly increases as comparison with that used in the conventional CT scan, which has raised major concerns in patients. In this study, to realize radiation dose reduction by reducing the X-ray tube current and exposure time (mAs) in repeated CT scans, we propose a prior-image induced nonlocal (PINL) regularization for statistical iterative reconstruction via the penalized weighted least-squares (PWLS) criteria, which we refer to as "PWLS-PINL". Specifically, the PINL regularization utilizes the redundant information in the prior image and the weighted least-squares term considers a data-dependent variance estimation, aiming to improve current low-dose image quality. Subsequently, a modified iterative successive overrelaxation algorithm is adopted to optimize the associative objective function. Experimental results on both phantom and patient data show that the present PWLS-PINL method can achieve promising gains over the other existing methods in terms of the noise reduction, low-contrast object detection, and edge detail preservation.

  3. Human thyroid specimen imaging by fluorescent x-ray computed tomography with synchrotron radiation

    Science.gov (United States)

    Takeda, Tohoru; Yu, Quanwen; Yashiro, Toru; Yuasa, Tetsuya; Hasegawa, Yasuo; Itai, Yuji; Akatsuka, Takao

    1999-09-01

    Fluorescent x-ray computed tomography (FXCT) is being developed to detect non-radioactive contrast materials in living specimens. The FXCT system consists of a silicon (111) channel cut monochromator, an x-ray slit and a collimator for fluorescent x ray detection, a scanning table for the target organ and an x-ray detector for fluorescent x-ray and transmission x-ray. To reduce Compton scattering overlapped on the fluorescent K(alpha) line, incident monochromatic x-ray was set at 37 keV. The FXCT clearly imaged a human thyroid gland and iodine content was estimated quantitatively. In a case of hyperthyroidism, the two-dimensional distribution of iodine content was not uniform, and thyroid cancer had a small amount of iodine. FXCT can be used to detect iodine within thyroid gland quantitatively and to delineate its distribution.

  4. Patient doses from x-ray examinations in Sweden - follow-up of remedial actions

    International Nuclear Information System (INIS)

    Joensson, Helene; Leitz, W.

    2002-03-01

    In early 1999 the Swedish Radiation Protection Authority (SSI) requested data about patient doses etc. for a number of specified x-ray examinations. The aim was on one hand to get a basis for planned regulations on diagnostic reference levels (DRL) and on the other hand to obtain an overview of how the situation is in the country with respect to patient doses. The licensees who reported dose values exceeding (provisional) DRL were asked to perform investigations about the grounds for the high dose and to take remedial actions for reducing the dose. In this report the outcome is presented. The dose reductions were large: on average between 35 and 60 % for the various examinations. A large proportion of the measures taken were simple and cheap, such as increase of radiation quality, improved examination methodology (smaller radiation fields, use of compression, reduced number of images or fluoroscopy time) and optimising the film processing. This is indicating that the planned regulations on diagnostic reference levels have a good chance to succeed with a large reduction of the patient doses in Sweden

  5. Ultrafast coherent diffractive imaging of nanoparticles using X-ray free-electron laser radiation

    International Nuclear Information System (INIS)

    Kassemeyer, Stephan

    2014-01-01

    Coherent diffractive imaging with X-ray free-electron lasers (X-FEL) promises high-resolution structure determination of single microscopic particles without the need for crystallization. The diffraction signal of small samples can be very weak, a difficulty that can not be countered by merely increasing the number of photons because the sample would be damaged by a high absorbed radiation dose. Traditional X-ray crystallography avoids this problem by bringing many sample particles into a periodic arrangement, which amplifies the individual signals while distributing the absorbed dose. Depending on the sample, however, crystallization can be very difficult or even impossible. This thesis presents algorithms for a new imaging approach using X-FEL radiation that works with single, non-crystalline sample particles. X-FELs can deliver X-rays with a peak brilliance many orders of magnitude higher than conventional X-ray sources, compensating for their weak interaction cross sections. At the same time, FELs can produce ultra-short pulses down to a few femtoseconds. In this way it is possible to perform ultra-fast imaging, essentially ''freezing'' the atomic positions in time and terminating the imaging process before the sample is destroyed by the absorbed radiation. This thesis primarily focuses on the three-dimensional reconstruction of single (and not necessarily crystalline) particles using coherent diffractive imaging at X-FELs: in order to extract three-dimensional information from scattering data, two-dimensional diffraction patterns from many different viewing angles must be combined. Therefore, the diffraction signal of many identical sample copies in random orientations is measured. The main result of this work is a globally optimal algorithm that can recover the sample orientations solely based on the diffraction signal, enabling three-dimensional imaging for arbitrary samples. The problem of finding three-dimensional orientations is

  6. Fourier domain image fusion for differential X-ray phase-contrast breast imaging

    International Nuclear Information System (INIS)

    Coello, Eduardo; Sperl, Jonathan I.; Bequé, Dirk; Benz, Tobias; Scherer, Kai; Herzen, Julia; Sztrókay-Gaul, Anikó; Hellerhoff, Karin; Pfeiffer, Franz; Cozzini, Cristina; Grandl, Susanne

    2017-01-01

    X-Ray Phase-Contrast (XPC) imaging is a novel technology with a great potential for applications in clinical practice, with breast imaging being of special interest. This work introduces an intuitive methodology to combine and visualize relevant diagnostic features, present in the X-ray attenuation, phase shift and scattering information retrieved in XPC imaging, using a Fourier domain fusion algorithm. The method allows to present complementary information from the three acquired signals in one single image, minimizing the noise component and maintaining visual similarity to a conventional X-ray image, but with noticeable enhancement in diagnostic features, details and resolution. Radiologists experienced in mammography applied the image fusion method to XPC measurements of mastectomy samples and evaluated the feature content of each input and the fused image. This assessment validated that the combination of all the relevant diagnostic features, contained in the XPC images, was present in the fused image as well.

  7. Fourier domain image fusion for differential X-ray phase-contrast breast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Coello, Eduardo, E-mail: eduardo.coello@tum.de [GE Global Research, Garching (Germany); Lehrstuhl für Informatikanwendungen in der Medizin & Augmented Reality, Institut für Informatik, Technische Universität München, Garching (Germany); Sperl, Jonathan I.; Bequé, Dirk [GE Global Research, Garching (Germany); Benz, Tobias [Lehrstuhl für Informatikanwendungen in der Medizin & Augmented Reality, Institut für Informatik, Technische Universität München, Garching (Germany); Scherer, Kai; Herzen, Julia [Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, Garching (Germany); Sztrókay-Gaul, Anikó; Hellerhoff, Karin [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich (Germany); Pfeiffer, Franz [Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, Garching (Germany); Cozzini, Cristina [GE Global Research, Garching (Germany); Grandl, Susanne [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich (Germany)

    2017-04-15

    X-Ray Phase-Contrast (XPC) imaging is a novel technology with a great potential for applications in clinical practice, with breast imaging being of special interest. This work introduces an intuitive methodology to combine and visualize relevant diagnostic features, present in the X-ray attenuation, phase shift and scattering information retrieved in XPC imaging, using a Fourier domain fusion algorithm. The method allows to present complementary information from the three acquired signals in one single image, minimizing the noise component and maintaining visual similarity to a conventional X-ray image, but with noticeable enhancement in diagnostic features, details and resolution. Radiologists experienced in mammography applied the image fusion method to XPC measurements of mastectomy samples and evaluated the feature content of each input and the fused image. This assessment validated that the combination of all the relevant diagnostic features, contained in the XPC images, was present in the fused image as well.

  8. 21 CFR 892.1630 - Electrostatic x-ray imaging system.

    Science.gov (United States)

    2010-04-01

    ... system. (a) Identification. An electrostatic x-ray imaging system is a device intended for medical... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrostatic x-ray imaging system. 892.1630... visible image. This generic type of device may include signal analysis and display equipment, patient and...

  9. Soft x-ray imaging by a commercial solid-state television camera

    International Nuclear Information System (INIS)

    Matsushima, I.; Koyama, K.; Tanimoto, M.; Yano, M.

    1987-01-01

    A commerical, solid-state television camera has been used to record images of soft x radiation (0.8--12 keV). The performance of the camera is theoretically analyzed and experimentally evaluated compared with an x-ray photographic film (Kodak direct exposure film). In the application, the camera has been used to provide image patterns of x rays from laser-produced plasmas. It is demonstrated that the camera has several advantages over x-ray photographic film

  10. Soft X-ray imaging by optically stimulated luminescence from color centers in lithium fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Bonfigli, F. [ENEA, C.R. Frascati, Via E. Fermi, 45, 00044 Frascati (Rome) (Italy)], E-mail: bonfigli@frascati.enea.it; Almaviva, S.; Baldacchini, G.; Bollanti, S.; Flora, F.; Lai, A.; Montereali, R.M. [ENEA, C.R. Frascati, Via E. Fermi, 45, 00044 Frascati (Rome) (Italy); Nichelatti, E. [ENEA, C.R. Casaccia, Via Anguillarese 301, 00060 S.Maria di Galeria (Rome) (Italy); Tomassetti, G.; Ritucci, A.; Reale, L. [Universita de L' Aquila e INFN, Dip. di Fisica, Coppito, L' Aquila (Italy); Faenov, A. Ya.; Pikuz, T.A. [MISDC of VNIIFTRI Mendeleevo, Moscow region, 141570 (Russian Federation); Larciprete, R. [ISC-CNR, Sezione Montelibretti, Via Salaria, Km. 29.3, 00016 Monterotondo Scalo (Rome) (Italy); Gregoratti, L.; Kiskinova, M. [Sincrotrone Trieste, S. S. 14, Km. 163.5, 34012 Basovizza (TS) (Italy)

    2007-07-15

    An innovative X-ray imaging detector based on Optically Stimulated Luminescence from color centers in lithium fluoride is presented. Regular photoluminescent patterns produced on LiF samples by different intense X-ray sources, like synchrotrons, laser plasma sources and a capillary discharge laser have been investigated by a Confocal Laser Scanning Microscope. The use of a LiF-based imaging plate for X-ray microscopy is also discussed showing microradiographies of small animals.

  11. The first X-ray imaging spectroscopy of quiescent solar active regions with NuSTAR

    DEFF Research Database (Denmark)

    Hannah, Iain G.; Grefenstette, Brian W.; Smith, David M.

    2016-01-01

    We present the first observations of quiescent active regions (ARs) using the Nuclear Spectroscopic Telescope Array (NuSTAR), a focusing hard X-ray telescope capable of studying faint solar emission from high-temperature and non-thermal sources. We analyze the first directly imaged and spectrally...... resolved X-rays above 2 keV from non-flaring ARs, observed near the west limb on 2014 November 1. The NuSTAR X-ray images match bright features seen in extreme ultraviolet and soft X-rays. The NuSTAR imaging spectroscopy is consistent with isothermal emission of temperatures 3.1-4.4 MK and emission...

  12. Magnetic resonance imaging of the central nervous system. Comparison with X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Kajima, Toshio; Kagawa, Yoshihiro; Katsuta, Shizutomo.

    1987-06-01

    Magnetic resonance imaging (MRI) and X-ray computed tomography (X-ray CT) have been performed in 169 consecutive patients with central nervous system diseases. The findings from the two methods were compared for the capacity to defect lesions. Magnetic resonance imaging was more sensitive than or equivalent to X-ray CT in detecting lesions - especially detecting. Arnold-Chiari malformation, syringomyelia, spinal cord injury, and pituitary adenoma - in 158 patients (94 %). In six patients (10 %), lesion detection was possible only by MRI. Magnetic resonance imaging was inferior to X-ray CT in 11 patients (7 %) in detecting calcified lesions, meningioma, and cavernous hemangioma. (Namekawa, K.).

  13. A computer code to simulate X-ray imaging techniques

    International Nuclear Information System (INIS)

    Duvauchelle, Philippe; Freud, Nicolas; Kaftandjian, Valerie; Babot, Daniel

    2000-01-01

    A computer code was developed to simulate the operation of radiographic, radioscopic or tomographic devices. The simulation is based on ray-tracing techniques and on the X-ray attenuation law. The use of computer-aided drawing (CAD) models enables simulations to be carried out with complex three-dimensional (3D) objects and the geometry of every component of the imaging chain, from the source to the detector, can be defined. Geometric unsharpness, for example, can be easily taken into account, even in complex configurations. Automatic translations or rotations of the object can be performed to simulate radioscopic or tomographic image acquisition. Simulations can be carried out with monochromatic or polychromatic beam spectra. This feature enables, for example, the beam hardening phenomenon to be dealt with or dual energy imaging techniques to be studied. The simulation principle is completely deterministic and consequently the computed images present no photon noise. Nevertheless, the variance of the signal associated with each pixel of the detector can be determined, which enables contrast-to-noise ratio (CNR) maps to be computed, in order to predict quantitatively the detectability of defects in the inspected object. The CNR is a relevant indicator for optimizing the experimental parameters. This paper provides several examples of simulated images that illustrate some of the rich possibilities offered by our software. Depending on the simulation type, the computation time order of magnitude can vary from 0.1 s (simple radiographic projection) up to several hours (3D tomography) on a PC, with a 400 MHz microprocessor. Our simulation tool proves to be useful in developing new specific applications, in choosing the most suitable components when designing a new testing chain, and in saving time by reducing the number of experimental tests

  14. A computer code to simulate X-ray imaging techniques

    Energy Technology Data Exchange (ETDEWEB)

    Duvauchelle, Philippe E-mail: philippe.duvauchelle@insa-lyon.fr; Freud, Nicolas; Kaftandjian, Valerie; Babot, Daniel

    2000-09-01

    A computer code was developed to simulate the operation of radiographic, radioscopic or tomographic devices. The simulation is based on ray-tracing techniques and on the X-ray attenuation law. The use of computer-aided drawing (CAD) models enables simulations to be carried out with complex three-dimensional (3D) objects and the geometry of every component of the imaging chain, from the source to the detector, can be defined. Geometric unsharpness, for example, can be easily taken into account, even in complex configurations. Automatic translations or rotations of the object can be performed to simulate radioscopic or tomographic image acquisition. Simulations can be carried out with monochromatic or polychromatic beam spectra. This feature enables, for example, the beam hardening phenomenon to be dealt with or dual energy imaging techniques to be studied. The simulation principle is completely deterministic and consequently the computed images present no photon noise. Nevertheless, the variance of the signal associated with each pixel of the detector can be determined, which enables contrast-to-noise ratio (CNR) maps to be computed, in order to predict quantitatively the detectability of defects in the inspected object. The CNR is a relevant indicator for optimizing the experimental parameters. This paper provides several examples of simulated images that illustrate some of the rich possibilities offered by our software. Depending on the simulation type, the computation time order of magnitude can vary from 0.1 s (simple radiographic projection) up to several hours (3D tomography) on a PC, with a 400 MHz microprocessor. Our simulation tool proves to be useful in developing new specific applications, in choosing the most suitable components when designing a new testing chain, and in saving time by reducing the number of experimental tests.

  15. X-ray image processing software for computing object size and object location coordinates from acquired optical and x-ray images

    International Nuclear Information System (INIS)

    Tiwari, Akash; Tiwari, Shyam Sunder; Tiwari, Railesha; Panday, Lokesh; Panday, Jeet; Suri, Nitin

    2004-01-01

    X-ray and Visible image data processing software has been developed in Visual Basic for real time online and offline image information processing for NDT and Medical Applications. Software computes two dimension image size parameters from its sharp boundary lines by raster scanning the image contrast data. Code accepts bit map image data and hunts for multiple tumors of different sizes that may be present in the image definition and then computes size of each tumor and locates its approximate center for registering its location coordinates. Presence of foreign metal and glass balls industrial product such as chocolate and other food items imaged out using x-ray imaging technique are detected by the software and their size and position co-ordinates are computed by the software. Paper discusses ways and means to compute size and coordinated of air bubble like objects present in the x-ray and optical images and their multiple existences in image of interest. (author)

  16. Radiation levels and image quality in patients undergoing chest X-ray examinations

    International Nuclear Information System (INIS)

    Campos de Oliveira, Paulo Márcio; Carmo Santana, Priscila do; Sousa Lacerda, Marco Aurélio de; Silva, Teógenes Augusto da

    2017-01-01

    Patient dose monitoring for different radiographic procedures has been used as a parameter to evaluate the performance of radiology services; skin entrance absorbed dose values for each type of examination were internationally established and recommended aiming patient protection. In this work, a methodology for dose evaluation was applied to three diagnostic services: one with a conventional film and two with digital computerized radiography processing techniques. The x-ray beam parameters were selected and “doses” (specifically the entrance surface and incident air kerma) were evaluated based on images approved in European criteria during postero-anterior (PA) and lateral (LAT) incidences. Data were collected from 200 patients related to 200 PA and 100 LAT incidences. Results showed that doses distributions in the three diagnostic services were very different; the best relation between dose and image quality was found in the institution with the chemical film processing. This work contributed for disseminating the radiation protection culture by emphasizing the need of a continuous dose reduction without losing the quality of the diagnostic image. - Highlights: • A methodology for dose evaluation was applied to three diagnostic services. • The doses in patients were evaluated when the images were adequate. • Data were collected from 200 patients. • Is possible doses optimization with digital system without an image quality reduction. • The best dose and image quality was found in chemical film processing.

  17. The impact of x-ray tube configuration on the eye lens and extremity doses received by cardiologists in electrophysiology room

    International Nuclear Information System (INIS)

    Domienik, J; Zmyślony, M; Bissinger, A

    2014-01-01

    The aim of the study was to analyse the influence of the x-ray tube configuration on the radiation doses to eye lens and extremities of cardiologists performing pacemaker implantation procedures in electrophysiology laboratory. The measurements were performed on one, widely used, portable C-arm system, first with x-ray tube mounted above the patient table and image intensifier below it and then on a reinstalled (but essentially the same) system with under-table x-ray tube configuration. Thermoluminescent dosimeters, placed in various positions near the eye lens, on the hands and ankle, were used during every procedure. The comparison of doses received by cardiologists after changing the x-ray tube configuration from over- to under-table shows statistically significant dose reduction (p < 0.009) for the eye lens closest to the x-ray tube, left finger, left wrist, while for the ankle a dose increase is observed. The corresponding over- to under-table x-ray tube median dose ratios are 4.1 for the right eye, 4.8 for the left finger, 3.0 for left wrist and, finally, 0.13 for the right ankle. Systems with under-table x-ray tube are preferable from a radiation protection point of view. The observed significant increase in doses to the legs should be partially compensated by the use of a protective lead curtain. (note)

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... clothing that might interfere with the x-ray images. Women should always inform their physician and x-ray ... lowest radiation dose possible while producing the best images for ... organizations continually review and update the technique standards used ...

  19. Phase-contrast tomographic imaging using an X-ray interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Momose, A. [Hitachi Ltd, Advanced Research Lab., Saitama (Japan); Takeda, T.; Itai, Y. [Univ. of Tsukuba, Inst. of Clinical Medicine, Ibaraki (Japan); Yoneyama, A. [Hitachi Ltd, Central Resarch Lab., Tokyo (Japan); Hirano, K. [High Energy Accelerator Research Organization, Inst. of Materials Structure Science, Ibaraki (Japan)

    1998-05-01

    Apparatus for phase-contrast X-ray computed tomography using a monolithic X-ray interferometer is presented with some observational results for human breast tissues. Structures characteristic of the tissues were revealed in the phase-contrast tomograms. The procedure of image analysis consists of phase retrieval from X-ray interference patterns and tomographic image reconstruction from the retrieved phase shift. Next, feasibility of phase-contrast imaging using a two-crystal X-ray interferometer was studied aiming at in vivo observation in the future. In a preliminary study, the two-crystal X-ray interferometer was capable of generating fringes of 70% visibility using synchrotron X-rays. 35 refs.

  20. Phase-contrast tomographic imaging using an X-ray interferometer

    International Nuclear Information System (INIS)

    Momose, A.; Takeda, T.; Itai, Y.; Yoneyama, A.; Hirano, K.

    1998-01-01

    Apparatus for phase-contrast X-ray computed tomography using a monolithic X-ray interferometer is presented with some observational results for human breast tissues. Structures characteristic of the tissues were revealed in the phase-contrast tomograms. The procedure of image analysis consists of phase retrieval from X-ray interference patterns and tomographic image reconstruction from the retrieved phase shift. Next, feasibility of phase-contrast imaging using a two-crystal X-ray interferometer was studied aiming at in vivo observation in the future. In a preliminary study, the two-crystal X-ray interferometer was capable of generating fringes of 70% visibility using synchrotron X-rays

  1. Transmission X-ray microscopy for full-field nano-imaging of biomaterials

    Science.gov (United States)

    ANDREWS, JOY C; MEIRER, FLORIAN; LIU, YIJIN; MESTER, ZOLTAN; PIANETTA, PIERO

    2010-01-01

    Imaging of cellular structure and extended tissue in biological materials requires nanometer resolution and good sample penetration, which can be provided by current full-field transmission X-ray microscopic techniques in the soft and hard X-ray regions. The various capabilities of full-field transmission X-ray microscopy (TXM) include 3D tomography, Zernike phase contrast, quantification of absorption, and chemical identification via X-ray fluorescence and X-ray absorption near edge structure (XANES) imaging. These techniques are discussed and compared in light of results from imaging of biological materials including microorganisms, bone and mineralized tissue and plants, with a focus on hard X-ray TXM at ≤ 40 nm resolution. PMID:20734414

  2. Transmission X-ray microscopy for full-field nano imaging of biomaterials.

    Science.gov (United States)

    Andrews, Joy C; Meirer, Florian; Liu, Yijin; Mester, Zoltan; Pianetta, Piero

    2011-07-01

    Imaging of cellular structure and extended tissue in biological materials requires nanometer resolution and good sample penetration, which can be provided by current full-field transmission X-ray microscopic techniques in the soft and hard X-ray regions. The various capabilities of full-field transmission X-ray microscopy (TXM) include 3D tomography, Zernike phase contrast, quantification of absorption, and chemical identification via X-ray fluorescence and X-ray absorption near edge structure imaging. These techniques are discussed and compared in light of results from the imaging of biological materials including microorganisms, bone and mineralized tissue, and plants, with a focus on hard X-ray TXM at ≤ 40-nm resolution. Copyright © 2010 Wiley-Liss, Inc.

  3. X-Ray imager power source on distribution trailers

    International Nuclear Information System (INIS)

    Johns, B.R.

    1996-01-01

    This Acceptance for Beneficial Use documents the work completed on the addition of an X-ray cable reel on distribution trailer HO-64-3533 for core sampling equipment. Work and documentation remaining to be completed is identified

  4. The influence of x-ray energy on lung dose uniformity in total-body irradiation

    International Nuclear Information System (INIS)

    Ekstrand, Kenneth; Greven, Kathryn; Wu Qingrong

    1997-01-01

    Purpose: In this study we examine the influence of x-ray energy on the uniformity of the dose within the lung in total-body irradiation treatments in which partial transmission blocks are used to control the lung dose. Methods and Materials: A solid water phantom with a cork insert to simulate a lung was irradiated by x-rays with energies of either 6, 10, or 18 MV. The source to phantom distance was 3.9 meters. The cork insert was either 10 cm wide or 6 cm wide. Partial transmission blocks with transmission factors of 50% were placed anterior to the cork insert. The blocks were either 8 or 4 cm in width. Kodak XV-2 film was placed in the midline of the phantom to record the dose. Midplane dose profiles were measured with a densitometer. Results: For the 10 cm wide cork insert the uniformity of the dose over 80% of the block width varied from 6.6% for the 6 MV x-rays to 12.2% for the 18 MV x-rays. For the 6 cm wide cork insert the uniformity was comparable for all three x-ray energies, but for 18 MV the central dose increased by 9.4% compared to the 10 cm wide insert. Conclusion: Many factors must be considered in optimizing the dose for total-body irradiation. This study suggests that for AP/PA techniques lung dose uniformity is superior with 6 MV irradiation. The blanket recommendation that the highest x-ray energy be used in TBI is not valid for all situations

  5. Radiation safety and quality in diagnostic x-ray imaging 2001

    International Nuclear Information System (INIS)

    Servomaa, A.; Parviainen, T.

    2001-05-01

    The obligations of the medical exposure directive (97/43/Euratom) for hospitals dominate the current activities in radiation protection in medical radiology. The directive gives special emphasis to radiation exposure of children, to examinations with high radiation doses and to radiation exposure in health screening programmes. The most important examinations with high doses are radiological interventions, where even acute skin effects are possible, and the computed tomography where the number of CT examinations makes only about 5% from the total number of x-ray examinations but the collective effective dose about 40% from the combined collective effective dose of all x-ray examinations. In the research projects financed by the European Commission, radiation exposures to paediatric patients have been measured in radiography, fluoroscopy and CT, and various dose assessment methods have been compared to develop a method for national follow-up of patients' radiation dose. The newest research project is focused on dosimetry and quality assurance in interventional radiology and digital imaging. Other actual topics are the development of radiation protection regulations and quality systems, education and training programmes, and clinical audits. This report deals with new radiation protection guides and recommendations and the education and training of radiological staff in radiation protection. One important topic is the development of national follow-up method of radiation exposure to patients and comparison of various dose assessment methods. Quality assurance in health care and in paediatric radiology, and the acceptance test and quality assurance measurements of radiological equipment are also described. (orig.)

  6. X-ray fluorescence imaging with synchrotron radiation

    International Nuclear Information System (INIS)

    Rivers, M.L.

    1987-01-01

    The micro-distribution of trace elements is of great interest in fields such as geochemistry, biology and material science. The synchrotron x-ray fluorescence microprobe provides a technique to quantitatively measure trace element compositions at individual points and to construct semiquantitative two dimensional maps of trace element compositions. This paper describes an x-ray fluorescence system used at the National Synchrotron Light Source

  7. Present status and future prospect of x-ray microscopes. Is it possible to realize x-ray 1 nm imaging?

    International Nuclear Information System (INIS)

    Aoki, Sadao

    2010-01-01

    High resolution X-ray imaging has been developed by using various optical elements and optical systems. In the soft X-ray region (∼3 nm) about 20 nm spatial resolution has been obtained, while in the hard X-ray (∼0.1 nm) about 50 nm. In the research frontier the spatial resolution better than 10 nm has been reported. The possibility to approach 1 nm spatial resolution is presented. (author)

  8. Evolution of the dose values and image quality for the X-ray of thorax postero/anterior in mature patients of the service of imagenology of the Hospital Dr. Juan Noe of Arica

    International Nuclear Information System (INIS)

    Ubeda, Carlos; Galaz, Sergio; Leyton, Fernando; Delgado, Otto; Espinosa, Alfonso; Inzulza, Alonso; Ramirez, Raul; Blanco, Daniel; Oyarzun, Carlos

    2008-01-01

    Full text: International Atomic Energy Agency defined guidance level for medical exposure, for the exams of general radiology, reason why the objective of the present work was to evaluate the evolution of the doses for the radiological exam of thorax posterior/anterior among the years 2005 at 2007. The used design was of traverse, descriptive, analytic and comparative type. The study population corresponded to 2 groups of 50 patients selected at random, of both sexes that attended the imagenology service of the public hospital Dr. Juan Noe Crevanni of the city of Arica, to be carried out a X-ray of thorax posterior/anterior. The first group of patients corresponded the participants in the project ARCAL LXXV (Determination of guidance level for Conventional Radiology and Interventionist) carried out in the year 2005. The second group of patients was those incorporate ones during the year 2007 to the project RLA/9/057 (Radiological Protection of Patient in Medical Exhibitions). Both investigations were sponsored by the International Atomic Energy Agency, The Institute of Health Publishes and the Chilean Commission of Nuclear Energy. The stages of the study were divided in: characterization of the yield of the teams, taking of exams, evaluation image quality, estimate of the dose values and statistical analysis. The mean values from entrance surface air kerma for the radiological exam of thorax posterior/anterior vary of 0,14 mGy (S.D. 0.29) to 0.08 mGy (S.D. 0.31), among the years 2005 and 2007 respectively, being this significant difference (p=0.001). Both values are inferior to the value recommended in the Adenda III of the BSS. As for the proportions of execution of the approaches of image quality this it was of 0.95 for the project ARCAL LXXV and 0.92 for the project RLA/9/057, without being this significant difference. The continuous evaluation of the guidance level for medical exposure, associated to the quality of the images constitutes an estimator on the

  9. The present state and future development of X-ray imaging technology

    International Nuclear Information System (INIS)

    Gou Liang; Wang Xuben; Cao Hui

    2002-01-01

    Medical imaging has long been the hot topic of clinical medical sciences, the X-ray imaging equipment is a popular device of current medical imaging, and the digital imaging technology has become a challenge to the conventional plane imaging. The author first discusses that the key of X-ray-based imaging is the generator and detector of X-ray and the improvement of imaging software, and then points out that the future development of medical imaging will aim at the capability of reducing radiation and handling more efficient and accurate data capacity

  10. Study of the variation of radiation dose in function of the radiological techniques used in X-ray diagnosis exams

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Marco A.R., E-mail: marfernandes@fmb.unesp.br [Faculty of Medicine. UNESP, Botucatu (FMB), SP (Brazil); Reis, Charlene O.; Garcia, Paulo L. [Institute of Biosciences of Botucatu. UNESP, Botucatu, SP (Brazil); Nucleate Radiometry Ltd., Aracatuba, SP (Brazil); Lima, Marcelo A.F.; Dalaqua, Fernando L.D. [UNESP, Botucatu, SP (Brazil). Hospital. Radiology Service

    2011-07-01

    This paper values the importance of the implantation of a quality control program in medical x-ray diagnosis services that it seeks mainly to the reduction of the radiation dose applied in the radiology exams, and attempt to the precepts of the Effective Legislation as for the Basic Guidelines of Radiological Protection (law decree MS no. 453 in June 1{sup st} 1998). The study was accomplished Radiology Section of the Medicine Faculty - FMB (UNESP - Botucatu) and it consisted of the accomplishment of measures of the radiation dose applied in the radiological exams, taking as base the x-rays techniques realized by four technicians in radiology the service, using only one x-rays equipment. Was intended analyze the variation of the radiation dose in function of the different applied technical parameters, and this way, guide the professionals as for the possibility of obtaining of x-ray images of better quality and smaller patient exposition. For radiation dose measure a detector of solid state was utilized. During the accomplishment of the measures it was verified that there no a general consensus among the technicians of the section being observed differences of the order of 80% in the mAs. In terms of radiation dose measured, the largest value of verified was 4.752 mGy (exam of lateral lumbar column) and the smallest value of 0.165 mGy (child's thorax).The results showed that a standardization in the x-ray techniques executed by the professionals of the section will be able to reduce significantly the radiation exposition of the assisted patients. (author)

  11. Study of the variation of radiation dose in function of the radiological techniques used in X-ray diagnosis exams

    International Nuclear Information System (INIS)

    Fernandes, Marco A.R.; Reis, Charlene O.; Garcia, Paulo L.; Lima, Marcelo A.F.; Dalaqua, Fernando L.D.

    2011-01-01

    This paper values the importance of the implantation of a quality control program in medical x-ray diagnosis services that it seeks mainly to the reduction of the radiation dose applied in the radiology exams, and attempt to the precepts of the Effective Legislation as for the Basic Guidelines of Radiological Protection (law decree MS no. 453 in June 1 st 1998). The study was accomplished Radiology Section of the Medicine Faculty - FMB (UNESP - Botucatu) and it consisted of the accomplishment of measures of the radiation dose applied in the radiological exams, taking as base the x-rays techniques realized by four technicians in radiology the service, using only one x-rays equipment. Was intended analyze the variation of the radiation dose in function of the different applied technical parameters, and this way, guide the professionals as for the possibility of obtaining of x-ray images of better quality and smaller patient exposition. For radiation dose measure a detector of solid state was utilized. During the accomplishment of the measures it was verified that there no a general consensus among the technicians of the section being observed differences of the order of 80% in the mAs. In terms of radiation dose measured, the largest value of verified was 4.752 mGy (exam of lateral lumbar column) and the smallest value of 0.165 mGy (child's thorax).The results showed that a standardization in the x-ray techniques executed by the professionals of the section will be able to reduce significantly the radiation exposition of the assisted patients. (author)

  12. Neonatal doses from X ray examinations by birth weight in a neonatal intensive care unit

    Energy Technology Data Exchange (ETDEWEB)

    Ono, K.; Akahane, K.; Aota, T.; Hada, M.; Takano, Y.; Kai, M.; Kusama, T

    2003-07-01

    The aim of this study was to investigate the frequency and type of X ray examinations performed on neonates classified according to their birth weight in a neonatal intensive care unit (NICU). In this study, the radiology records of 2408 neonates who were admitted to the NICU of Oita Prefectural Hospital between January 1994 and September 1999 were investigated. This study revealed that the neonates with earlier gestational ages and lower birth weights required longer NICU stays and more frequent X ray examinations made using a mobile X ray unit. The average number of X ray examinations performed on neonates of less than 750 g birth weight was 26 films per neonate. In regard to computed tomography and fluoroscopy, no significant relationship was found between the birth weight and number of X rays. This study revealed that the entrance-surface dose per neonate was dependent upon the birth weight, while the maximum dose was not dependent upon the birth weight. The average neonatal dose in the NICU was predominantly from computed tomography and fluoroscopy. The individual dose varied widely among neonates. (author)

  13. Neonatal doses from X ray examinations by birth weight in a neonatal intensive care unit

    International Nuclear Information System (INIS)

    Ono, K.; Akahane, K.; Aota, T.; Hada, M.; Takano, Y.; Kai, M.; Kusama, T.

    2003-01-01

    The aim of this study was to investigate the frequency and type of X ray examinations performed on neonates classified according to their birth weight in a neonatal intensive care unit (NICU). In this study, the radiology records of 2408 neonates who were admitted to the NICU of Oita Prefectural Hospital between January 1994 and September 1999 were investigated. This study revealed that the neonates with earlier gestational ages and lower birth weights required longer NICU stays and more frequent X ray examinations made using a mobile X ray unit. The average number of X ray examinations performed on neonates of less than 750 g birth weight was 26 films per neonate. In regard to computed tomography and fluoroscopy, no significant relationship was found between the birth weight and number of X rays. This study revealed that the entrance-surface dose per neonate was dependent upon the birth weight, while the maximum dose was not dependent upon the birth weight. The average neonatal dose in the NICU was predominantly from computed tomography and fluoroscopy. The individual dose varied widely among neonates. (author)

  14. Collective effective dose in Europe from x-ray and nuclear medicine procedures

    International Nuclear Information System (INIS)

    Bly, R.; Jaervinen, H.; Jahnen, A.; Olerud, H.; Vassileva, J.; Vogiatzi, S.

    2015-01-01

    Population doses from radiodiagnostic (X-ray and nuclear medicine) procedures in Europe were estimated based on data collected from 36 European countries. For X-ray procedures in EU and EFTA countries (except Liechtenstein) the collective effective dose is 547 500 man Sv, resulting in a mean effective dose of 1.06 mSv per caput. For all European countries included in the survey the collective effective dose is 605 000 man Sv, resulting in a mean effective dose of 1.05 mSv per caput. For nuclear medicine procedures in EU countries and EFTA (except Liechtenstein) countries the collective effective dose is 30 700 man Sv, resulting in a mean effective dose of 0.06 mSv per caput. For all European countries included in the survey the collective effective dose is 31 100 man Sv, resulting in a mean effective dose of 0.05 mSv per caput. (authors)

  15. New gonad protector for public survey X-ray images

    Energy Technology Data Exchange (ETDEWEB)

    Joos, M.

    1976-01-01

    A new gonad shield intended to be used for pubic survey X-ray images is introduced. This protector is mounted on the light sight and produces a shadow free of central radiation on the patient's body. The shield provides such a shape that in women the area limited by the terminal line and in which 95% of the ovaria are situated, is covered, and that in men the region below the pubic angle is protected. The 2 mm thick lead shield has dimensions of 4.0 to 2.5 cm and is inserted into a plexiglass ruler which lies freely movable on a plexiglass plate under the light sight. This shield was tested on the water phantom and on 125 patients. With this protector it was possible to lower the surface dosages calculated by film dosimeters to 20% in women, and also to reduce the gonade dosages to 9% of the dosages without protection. The position of the new gonad protector at a distance from the body provides several advantages: the shield does not alter its position when the patient moves, the protector does not slip off the abdomen in adipose female patients, the radiation protected region has always the same extent, independent from the abdominal curvature of the female patient, the hygienic problems are eliminated, and the shield can be used for both sexes.

  16. Federated repositories of X-ray diffraction images.

    Science.gov (United States)

    Androulakis, Steve; Schmidberger, Jason; Bate, Mark A; DeGori, Ross; Beitz, Anthony; Keong, Cyrus; Cameron, Bob; McGowan, Sheena; Porter, Corrine J; Harrison, Andrew; Hunter, Jane; Martin, Jennifer L; Kobe, Bostjan; Dobson, Renwick C J; Parker, Michael W; Whisstock, James C; Gray, Joan; Treloar, Andrew; Groenewegen, David; Dickson, Neil; Buckle, Ashley M

    2008-07-01

    There is a pressing need for the archiving and curation of raw X-ray diffraction data. This information is critical for validation, methods development and improvement of archived structures. However, the relatively large size of these data sets has presented challenges for storage in a single worldwide repository such as the Protein Data Bank archive. This problem can be avoided by using a federated approach, where each institution utilizes its institutional repository for storage, with a discovery service overlaid. Institutional repositories are relatively stable and adequately funded, ensuring persistence. Here, a simple repository solution is described, utilizing Fedora open-source database software and data-annotation and deposition tools that can be deployed at any site cheaply and easily. Data sets and associated metadata from federated repositories are given a unique and persistent handle, providing a simple mechanism for search and retrieval via web interfaces. In addition to ensuring that valuable data is not lost, the provision of raw data has several uses for the crystallographic community. Most importantly, structure determination can only be truly repeated or verified when the raw data are available. Moreover, the availability of raw data is extremely useful for the development of improved methods of image analysis and data processing.

  17. X-ray image segmentation for vertebral mobility analysis

    International Nuclear Information System (INIS)

    Benjelloun, Mohammed; Mahmoudi, Said

    2008-01-01

    The goal of this work is to extract the parameters determining vertebral motion and its variation during flexion-extension movements using a computer vision tool for estimating and analyzing vertebral mobility. To compute vertebral body motion parameters we propose a comparative study between two segmentation methods proposed and applied to lateral X-ray images of the cervical spine. The two vertebra contour detection methods include (1) a discrete dynamic contour model (DDCM) and (2) a template matching process associated with a polar signature system. These two methods not only enable vertebra segmentation but also extract parameters that can be used to evaluate vertebral mobility. Lateral cervical spine views including 100 views in flexion, extension and neutral orientations were available for evaluation. Vertebral body motion was evaluated by human observers and using automatic methods. The results provided by the automated approaches were consistent with manual measures obtained by 15 human observers. The automated techniques provide acceptable results for the assessment of vertebral body mobility in flexion and extension on lateral views of the cervical spine. (orig.)

  18. In-Line Phase-Contrast X-ray Imaging and Tomography for Materials Science.

    Science.gov (United States)

    Mayo, Sheridan C; Stevenson, Andrew W; Wilkins, Stephen W

    2012-05-24

    X-ray phase-contrast imaging and tomography make use of the refraction of X-rays by the sample in image formation. This provides considerable additional information in the image compared to conventional X-ray imaging methods, which rely solely on X-ray absorption by the sample. Phase-contrast imaging highlights edges and internal boundaries of a sample and is thus complementary to absorption contrast, which is more sensitive to the bulk of the sample. Phase-contrast can also be used to image low-density materials, which do not absorb X-rays sufficiently to form a conventional X-ray image. In the context of materials science, X-ray phase-contrast imaging and tomography have particular value in the 2D and 3D characterization of low-density materials, the detection of cracks and voids and the analysis of composites and multiphase materials where the different components have similar X-ray attenuation coefficients. Here we review the use of phase-contrast imaging and tomography for a wide variety of materials science characterization problems using both synchrotron and laboratory sources and further demonstrate the particular benefits of phase contrast in the laboratory setting with a series of case studies.

  19. X-ray absorbed doses evaluation on patients under radiological studies

    International Nuclear Information System (INIS)

    Medeiros, Regina Bitelli; Daros, Kellen A.C.

    1996-01-01

    The skin absorbed doses were evaluated on patient submitted to the following x-ray exams : chest, facial sinus, lumbar spine. Thermoluminescent dosimetry was used and a variety of irradiation techniques performed. The results shown considerable differences on the absorbed dose for the various alternative technical conditions

  20. Skin Entrance dose to patients from routine P-A chest X-ray ...

    African Journals Online (AJOL)

    Background: Radiation of any amount is potentially hazardous and it should be minimized as much as possible during health care delivery. Objective: To determine and assess the variation of the dose received by patients undergoing chest x-ray examination, and to provide a useful baseline data to evaluate the dose to the ...