WorldWideScience

Sample records for clinical megavoltage x-ray

  1. The race for megavoltage. X-rays versus telegamma.

    Science.gov (United States)

    Robison, R F

    1995-01-01

    Roentgen's discovery was announced in January, 1896, and x-ray therapy trials followed in 1897. Becquerel rays and radioactive minerals were identified during 1896 through 1898. Radium was used for therapy by 1901, even though a pure standard was not achieved until 1910-1912. Quantities of radium finally became available after 1919, and for 20 years telegamma therapy machines underwent progressive development. Their megavoltage beam was much preferred over the standard 200-250 KV x-ray units of that time. Nuclear physicists during the Great Depression modified electron accelerators into giant 600-900 KV medical x-ray therapy machines and achieved one MV by 1937-1939. These were huge, complex, expensive, and unique to major academic and/or metropolitan centers. During World War II nuclear reactors superseded cyclotrons as efficient factories for few new radioisotopes, including "artificial radium". Few seemed interested in the latter for use in telegamma therapy until 1949-1951, when three competing teams from Canada and the USA designed telecobalt machines. From this competition, among then unknown innovators, emerged three future giants in radiation therapy: A.E.C.L., H. Johns, and G.H. Fletcher. The clinical application of telecobalt therapy was to revolutionize cancer care in community hospitals worldwide.

  2. Megavoltage X-Ray Imaging Based on Cerenkov Effect: A New Application of Optical Fibres to Radiation Therapy

    Directory of Open Access Journals (Sweden)

    A. Teymurazyan

    2012-01-01

    Full Text Available A Monte Carlo simulation was used to study imaging and dosimetric characteristics of a novel design of megavoltage (MV X-ray detectors for radiotherapy applications. The new design uses Cerenkov effect to convert X-ray energy absorbed in optical fibres into light for MV X-ray imaging. The proposed detector consists of a matrix of optical fibres aligned with the incident X rays and coupled to an active matrix flat-panel imager (AMFPI for image readout. Properties, such as modulation transfer function, detection quantum efficiency (DQE, and energy response of the detector, were investigated. It has been shown that the proposed detector can have a zero-frequency DQE more than an order of magnitude higher than that of current electronic portal imaging device (EPID systems and yet a spatial resolution comparable to that of video-based EPIDs. The proposed detector is also less sensitive to scattered X rays from patients than current EPIDs.

  3. Real-time segmentation of multiple implanted cylindrical liver markers in kilovoltage and megavoltage x-ray images

    DEFF Research Database (Denmark)

    Fledelius, Walther; Worm, Esben Schjødt; Høyer, Morten;

    2014-01-01

    Gold markers implanted in or near a tumor can be used as x-ray visible landmarks for image based tumor localization. The aim of this study was to develop and demonstrate fast and reliable real-time segmentation of multiple liver tumor markers in intra-treatment kV and MV images and in cone-beam CT...... for automatic generation of a 3D marker model that consisted of the size, orientation, and estimated 3D trajectory of each marker during the CBCT scan. The 3D marker model was used for real-time template based segmentation in subsequent x-ray images by projecting each marker's 3D shape and likely 3D motion...... range onto the imager plane. The segmentation was performed in intra-treatment kV images (526 marker traces, 92 097 marker projections) and MV images (88 marker traces, 22 382 marker projections), and in post-treatment CBCT projections (42 CBCT scans, 71 381 marker projections). 227 kV marker traces...

  4. Sci—Thur PM: Imaging — 03: A novel Čerenkov detector based on air-spaced light guiding taper for megavoltage x-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Teymurazyan, A [Imaging Research, Sunnybrook Health Sciences Centre, Department of Medical Biophysics, University of Toronto, Toronto (Canada); Rowlands, J A [Thunder Bay Regional Research Institute (IBRRI), Thunder Bay (Canada); Department of Radiation Oncology, University of Toronto, Toronto (Canada); Pang, G [Imaging Research, Sunnybrook Health Sciences Centre, Department of Medical Biophysics, University of Toronto, Toronto (Canada); Department of Radiation Oncology, University of Toronto, Toronto (Canada); Odette Cancer Centre, Toronto (Canada); Department of Physics, Ryerson University, Toronto (Canada)

    2014-08-15

    Electronic Portal Imaging Devices (EPIDs) have been used in radiation therapy and are still needed on linear accelerators (Linacs) equipped with kilovoltage cone beam CT (kV-CBCT) or MRI systems. Recently a new concept of a high quantum efficiency (QE) Čerenkov Portal Imaging Device (CPID) for MV x-ray imaging in radiation therapy was introduced. It relies on Čerenkov effect for x-ray detection. The proposed design consisted of a matrix of optical fibres aligned with the incident x-rays and coupled to an active matrix flat panel imager (AMFPI) for image readout. A weakness of such design is that too few Čerenkov light photons reach the AMFPI for each incident x-ray and an AMFPI with an avalanche gain is required. In this work we propose to replace the optical fibers in the CPID with light guides without a cladding layer that are suspended in air. The air between the light guides takes on the role of the cladding layer found in a regular optical fiber. Since air has a significantly lower refractive index, a much superior light collection efficiency is achieved. Our Monte Carlo studies have shown that the modified new CPID has a QE more than an order of magnitude greater than that of current clinical systems and yet a spatial resolution similar to that of current flat-panel based EPIDs. Furthermore it has been demonstrated that the new CPID does not require an avalanche gain in the AMFPI and is quantum noise limited at dose levels corresponding to a single Linac pulse.

  5. Monte Carlo simulation of a quantum noise limited Čerenkov detector based on air-spaced light guiding taper for megavoltage x-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Teymurazyan, A. [Imaging Research, Sunnybrook Health Sciences Centre, Department of Medical Biophysics, University of Toronto, Toronto M4N 3M5 (Canada); Rowlands, J. A. [Imaging Research, Sunnybrook Health Sciences Centre, Department of Medical Biophysics, University of Toronto, Toronto M4N 3M5 (Canada); Thunder Bay Regional Research Institute (TBRRI), Thunder Bay P7A 7T1 (Canada); Department of Radiation Oncology, University of Toronto, Toronto M5S 3E2 (Canada); Pang, G., E-mail: geordi.pang@sunnybrook.ca [Imaging Research, Sunnybrook Health Sciences Centre, Department of Medical Biophysics, University of Toronto, Toronto M4N 3M5 (Canada); Department of Radiation Oncology, University of Toronto, Toronto M5S 3E2 (Canada); Odette Cancer Centre, Toronto M4N 3M5 (Canada); Department of Physics, Ryerson University, Toronto M5B 2K3 (Canada)

    2014-04-15

    Purpose: Electronic Portal Imaging Devices (EPIDs) have been widely used in radiation therapy and are still needed on linear accelerators (Linacs) equipped with kilovoltage cone beam CT (kV-CBCT) or MRI systems. Our aim is to develop a new high quantum efficiency (QE) Čerenkov Portal Imaging Device (CPID) that is quantum noise limited at dose levels corresponding to a single Linac pulse. Methods: Recently a new concept of CPID for MV x-ray imaging in radiation therapy was introduced. It relies on Čerenkov effect for x-ray detection. The proposed design consisted of a matrix of optical fibers aligned with the incident x-rays and coupled to an active matrix flat panel imager (AMFPI) for image readout. A weakness of such design is that too few Čerenkov light photons reach the AMFPI for each incident x-ray and an AMFPI with an avalanche gain is required in order to overcome the readout noise for portal imaging application. In this work the authors propose to replace the optical fibers in the CPID with light guides without a cladding layer that are suspended in air. The air between the light guides takes on the role of the cladding layer found in a regular optical fiber. Since air has a significantly lower refractive index (∼1 versus 1.38 in a typical cladding layer), a much superior light collection efficiency is achieved. Results: A Monte Carlo simulation of the new design has been conducted to investigate its feasibility. Detector quantities such as quantum efficiency (QE), spatial resolution (MTF), and frequency dependent detective quantum efficiency (DQE) have been evaluated. The detector signal and the quantum noise have been compared to the readout noise. Conclusions: Our studies show that the modified new CPID has a QE and DQE more than an order of magnitude greater than that of current clinical systems and yet a spatial resolution similar to that of current low-QE flat-panel based EPIDs. Furthermore it was demonstrated that the new CPID does not require an

  6. 3D Reconstruction from X-ray Fluoroscopy for Clinical Veterinary Medicine using Differential Volume Rendering

    Science.gov (United States)

    Khongsomboon, Khamphong; Hamamoto, Kazuhiko; Kondo, Shozo

    3D reconstruction from ordinary X-ray equipment which is not CT or MRI is required in clinical veterinary medicine. Authors have already proposed a 3D reconstruction technique from X-ray photograph to present bone structure. Although the reconstruction is useful for veterinary medicine, the thechnique has two problems. One is about exposure of X-ray and the other is about data acquisition process. An x-ray equipment which is not special one but can solve the problems is X-ray fluoroscopy. Therefore, in this paper, we propose a method for 3D-reconstruction from X-ray fluoroscopy for clinical veterinary medicine. Fluoroscopy is usually used to observe a movement of organ or to identify a position of organ for surgery by weak X-ray intensity. Since fluoroscopy can output a observed result as movie, the previous two problems which are caused by use of X-ray photograph can be solved. However, a new problem arises due to weak X-ray intensity. Although fluoroscopy can present information of not only bone structure but soft tissues, the contrast is very low and it is very difficult to recognize some soft tissues. It is very useful to be able to observe not only bone structure but soft tissues clearly by ordinary X-ray equipment in the field of clinical veterinary medicine. To solve this problem, this paper proposes a new method to determine opacity in volume rendering process. The opacity is determined according to 3D differential coefficient of 3D reconstruction. This differential volume rendering can present a 3D structure image of multiple organs volumetrically and clearly for clinical veterinary medicine. This paper shows results of simulation and experimental investigation of small dog and evaluation by veterinarians.

  7. Development of X-ray dark-field imaging towards clinical application

    Institute of Scientific and Technical Information of China (English)

    ANDO Masami; RUBENSTEIN Edward; ROBERSON Joseph; SHIMAO Daisuke; SUGIYAMA Hiroshi; TAKEDA Ken; UENO Ei; WADA Hiroshi; HASHIMOTO Eiko; HASHIZUME Hiroyuki; HYODO Kazuyuki; INOUE Hajime; ISHIKAWA Tetsuya; KUNISADA Toshiyuki; MAKSIMENKO Anton; PATTANASIRIWISAWA Wanwisa

    2004-01-01

    Review of X-ray dark-field imaging under development is presented. Its goal is its application to clinical diagnosis of organs that have been invisible by the ordinary techniques. In order to clinically visualize tissues in detail one needs high contrast and high spatial resolution say ~50 μm. This X-ray optics comprises a Bragg asymmetric monochro-collimator and a Bragg case or a Laue case filter with capability of analyzing angle in a parallel position. Their diffraction index is 4,4,0 and the X-ray energy 35 keV (λ= 0.0354 nm). The filter has 0.6 mm thickness in the Bragg case or 1.075 mm or 2.15 mm thickness in the Laue case. Under this condition only the refracted X-rays from object can transmit through the filter while the beam that may receive absorption and/or phase change will not. Soft tissues at human joints thus taken show high contrast images so that the DFI is promising for clinical diagnosis. Preliminary X-ray absorption images of another clinical candidates of ear bones are also shown.

  8. The practical training of students - x-ray technicians and requirements to mentors in clinical bases

    International Nuclear Information System (INIS)

    Full text: Introduction: Training of X-ray technicians in Bulgaria takes place in the Medical Colleges to Medical Universities. It's purpose is providing professional training of students in the area of diagnostic imaging, nuclear medicine and radiotherapy. Practical training is based on the scientific and theoretical knowledge and skills and is organized in pedagogic environment, adequate to regularities for a gradual formation of practical skills and habits. The practical training and pre-graduation internship are performed in 1895 from total of 3810 hours, which represents about fifty percent of all training of X-ray technicians. Students are in groups of 2-4 students. Practical training is organized, accomplished and monitored by the teacher training practice with the help of a mentor in the clinical base. Purpose: To present the tasks of practical training of students - X-ray technicians and the requirements for the personal characteristics and activity of mentors. Materials and methods: Documentary method has been used. Literature and normative documents related to the practical training of students in 'X-ray technician' of Medical Colleges have been studied. The job descriptions of senior clinical X-ray technicians have been examined carefully. Results: By analyzing literature sources, we have structured the tasks of practical training and pre-graduation internship of students - X-ray technicians, also we have described the requirements for personal qualities of mentors and systematize the activities they perform. Conclusion: Practical training plays an important role in adaptation of young X-ray technicians to the conditions of medical work, improving their skills and habits, and to the development of specific practical skills for being able to respond to emergency conditions and to solve complicated practical situations. The mentor is the supervisor and the controller of interns who helps this happen through his own example, qualities and attitudes towards

  9. An Integrated X-Ray/Optical Tomography System for Pre-clinical Radiation Research

    OpenAIRE

    Eslami, S.; Yang, Y.; Wong, J; Patterson, M S; Iordachita, I.

    2013-01-01

    The current Small Animal Radiation Research Platform (SARRP) is poor for localizing small soft tissue targets for irradiation or tumor models growing in a soft tissue environment. Therefore, an imaging method complementary to x-ray CT is required to localize the soft tissue target’s Center of Mass (CoM) to within 1 mm. In this paper, we report the development of an integrated x-ray/bioluminescence imaging/tomography (BLI/BLT) system to provide a pre-clinical, high resolution irradiation syste...

  10. Infant Hip Joint Diagnostic Support System Based on Clinical Manifestations in X-ray Images

    OpenAIRE

    Honda, Mitsugi; Arita, Seizaburo; Mitani, Shigeru; TAKEDA, Yoshihiro; Ozaki,Toshifumi; Inamura, Keiji; Kanazawa, Susumu

    2010-01-01

    Plain X-ray radiography is frequently used for the diagnosis of developmental dislocation of the hip (DDH). The aim of this study was to construct a diagnostic support system for DDH based on clinical findings obtained from the X-ray images of 154 female infants with confirmed diagnoses made by orthopedists. The data for these subjects were divided into 2 groups. The Min-Max method of nonlinear analysis was applied to the data from Group 1 to construct the diagnostic support system based on t...

  11. Infant Hip Joint Diagnostic Support System Based on Clinical Manifestations in X-ray Images

    Directory of Open Access Journals (Sweden)

    Honda,Mitsugi

    2010-06-01

    Full Text Available Plain X-ray radiography is frequently used for the diagnosis of developmental dislocation of the hip (DDH. The aim of this study was to construct a diagnostic support system for DDH based on clinical findings obtained from the X-ray images of 154 female infants with confirmed diagnoses made by orthopedists. The data for these subjects were divided into 2 groups. The Min-Max method of nonlinear analysis was applied to the data from Group 1 to construct the diagnostic support system based on the measurement of 4 items in X-ray images:the outward displacement rate, upward displacement rate, OE angle, and alpha angle. This system was then applied to the data from Group 2, and the results were compared between the 2 groups to verify the reliability of the system. We obtained good results that matched the confirmed diagnoses of orthopedists with an accuracy of 85.9%.

  12. X-ray and clinical characteristics of mycoplasma pneumonia in children

    International Nuclear Information System (INIS)

    Analysis in a roentgen-clinical aspect was made in 116 children, 6 months to 14 years of age, who have had micaplasma pneumonia, proved serologically by the complement fixation test. Two basic roentgenological forms were distinguished: parenchymatous-interstitial (in two thirds of the children) and interstitial-congestive (in one third). Fourty two children had pleural involvement: in 39 the interlobal pleura was involved and in only three the lateral pleura. Only one child had a small pleural effusion in the costodiaphragmatic sinus. In either X-ray form of the disease the hilar markings were exaggerated and the perihilar lung vessels dilated. These changes persisted for quite a long while. Complete resolution of the X-ray changes occurred between the 10th and the 30th day after the onset of the disease. The clinical manifestations were discussed separately for each X-ray form. It is assumed that there are early X-ray and clinical symptoms which may suggest mycoplasma pneumonia since the onset of the disease. (authors)

  13. Considerations on scattering and leak radiation for effective determination of secondary shielding in X-rays rooms of megavoltage; Consideracoes sobre radiacoes de espalhamento e vazamento para determinacao eficaz da barreira secundaria em salas de raios-x de megavoltagem

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Diogo da S.; Lava, Deise D.; Affonso, Renato R.W.; Moreira, Maria de L.; Guimaraes, Antonio C.F., E-mail: diogosb@outlook.com, E-mail: deise_dy@hotmail.com, E-mail: raoniwa@yahoo.com.br, E-mail: malu@ien.gov.br, E-mail: tony@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    This paper addresses the development of a algorithm capable of analyzing the thickness of the secondary shielding due to the production of secondary beams. The production of this beam requires consideration of scattering angle, as well as factors normally used for screening of medical facilities using radiographic techniques. Besides the beam emanated from scattering radiation, is is necessary to evaluate the contribution of leakage radiation, originating from equipment used for the production of the primary beam. A view of the mutual contribution of these radiation to the formation of the secondary beam has shown the need of using shieldings in adjacent walls of the room. The code was validated by comparison with an example case provided by NCRP-151 Report. In this report calculations for determining the secondary barrier for small angles are presented, that deserves greater attention for shielding and statements related to radiotherapy procedures of Modulated intensity. The results are consistent with those provided in the report, which makes the code can be used as a practical tool for the determination of effective shielding beams of megavoltage X-rays.

  14. X-Ray Imaging

    Science.gov (United States)

    ... Brain Surgery Imaging Clinical Trials Basics Patient Information X-Ray Imaging Print This Page X-ray imaging is perhaps the most familiar type of imaging. Images produced by X-rays are due to the different absorption rates of ...

  15. The use of portable X-ray Fluorescence Spectrometry (PXRFS) for clinical practices

    International Nuclear Information System (INIS)

    In the last years X-Ray Fluorescence (X RF) technique has been applied to clinical finality at IPEN/CNEN-S P, in collaboration with blood banks and research centers from Brazil. The major advantage for using this analytic technique for chemistry clinical is the viability to use small quantities of blood (25 to 100μL) comparatively to conventional analyses preformed using serum (at least 500 μL to 10 m L). Besides, the execution is faster and the procedure is not destructive. Now, we intend to check the viability of using a portable X- Ray Fluorescence Spectrometry (PXRFS) for clinical blood examination. In this study the biological samples came from Blood Banks of Sao Paulo city (Brazil). Each sample was collected in a vacuum plastic tube (without anticoagulants) attached to the donors arm and, immediately after the collection exactly, 100 μ L of whole blood was transferred to the filter paper (Whatman, n 41) using a calibrated micropipette and it was dried for few minutes using an infrared lamp. Samples were prepared in duplicate. The X RF analysis was performed using Mini X spectrometer from Amptek, model X-123 Sdd with Ag X-ray tube. The characteristics X-ray fluorescent intensities (Kα lines) were measured with a Si detector (Si Drift 25 m m2 x 500 μm / 0.5 mil) Be (window / 1.5) and biological samples were irradiated for 300s using 30 kV and 5 μA excitation. The quantitative analysis was performed using WINAXIL software program. We intend to stimulate the use of this small spectrometry as an alternative for diagnostic of the clinical diseases that have high prevalence in Brazilian population

  16. Clinical and X-ray findings of mycetoma (report of 18 cases)

    International Nuclear Information System (INIS)

    Objective: To investigate the characteristic clinical and X-ray findings of mycetoma and to enhance the understanding of mycetoma. Methods: The clinical and X-ray findings of mycetoma in 18 cases were analyzed with the review of literatures. There were 11 males and 7 females, the age ranged from 21-65 years, with the average of 41.5 year. The cases were all peasants, barefoot and with the history of trauma, which lasted for 4-17 years with the average of 9.8 year. Results: Sixty-seven lesions of bone in 18 cases (30 metatarsal, 20 cuneiform, 7 cuboid, 5 phalanx, 3 tibia, 2 calcaneus) were presented, including 8 rodent, 3 osteolytic, 3 cystic, 2 rodent and sclerosis changes, 2 sclerosis, 9 irregular thickened bony cortex, 7 irregular deleted bony cortex, 12 periosteal reaction, 3 irregular crest of bone in lesion, 13 rarefaction of bone cortex, 11 swimmy of surface arthrosis, 8 constriction of interval arthrosis, 2 spot calcification in the soft tissue, 2 sequestrum, and 2 soft tissue mass. The mycelium had been discovered in grain in 18 cases and the colour of grain was from brown to black. Conclusion: Mycetoma involves extensively and tends to involve multiple bones. The main X-ray findings are rodent and osteolytic changes

  17. 100 Years later: Celebrating the contributions of x-ray crystallography to allergy and clinical immunology.

    Science.gov (United States)

    Pomés, Anna; Chruszcz, Maksymilian; Gustchina, Alla; Minor, Wladek; Mueller, Geoffrey A; Pedersen, Lars C; Wlodawer, Alexander; Chapman, Martin D

    2015-07-01

    Current knowledge of molecules involved in immunology and allergic disease results from the significant contributions of x-ray crystallography, a discipline that just celebrated its 100th anniversary. The histories of allergens and x-ray crystallography are intimately intertwined. The first enzyme structure to be determined was lysozyme, also known as the chicken food allergen Gal d 4. Crystallography determines the exact 3-dimensional positions of atoms in molecules. Structures of molecular complexes in the disciplines of immunology and allergy have revealed the atoms involved in molecular interactions and mechanisms of disease. These complexes include peptides presented by MHC class II molecules, cytokines bound to their receptors, allergen-antibody complexes, and innate immune receptors with their ligands. The information derived from crystallographic studies provides insights into the function of molecules. Allergen function is one of the determinants of environmental exposure, which is essential for IgE sensitization. Proteolytic activity of allergens or their capacity to bind LPSs can also contribute to allergenicity. The atomic positions define the molecular surface that is accessible to antibodies. In turn, this surface determines antibody specificity and cross-reactivity, which are important factors for the selection of allergen panels used for molecular diagnosis and the interpretation of clinical symptoms. This review celebrates the contributions of x-ray crystallography to clinical immunology and allergy, focusing on new molecular perspectives that influence the diagnosis and treatment of allergic diseases.

  18. X-ray dark field imaging of human articular cartilage: Possible clinical application to orthopedic surgery

    International Nuclear Information System (INIS)

    Despite its convenience and non-invasiveness on daily clinical use, standard X-ray radiography cannot show articular cartilage. We developed a novel type of X-ray dark field imaging (DFI), which forms images only by a refracted beam with very low background illumination. We examined a disarticulated distal femur and a shoulder joint with surrounding soft tissue and skin, both excised from a human cadaver at the BL20B2 synchrotron beamline at SPring-8. The field was 90 mm wide and 90 mm high. Articular cartilage of the disarticulated distal femur was obvious on DFI, but not on standard X-ray images. Furthermore, DFI allowed visualization in situ of articular cartilage of the shoulder while covered with soft tissue and skin. The gross appearance of the articular cartilage on the dissected section of the proximal humerus was identical to the cartilage shown on the DFI image. These results suggested that DFI could provide a clinically accurate method of assessing articular cartilage. Hence, DFI would be a useful imaging tool for diagnosing joint disease such as osteoarthritis

  19. Hospital and clinic survey estimates of medical x-ray exposures in Hiroshima and Nagasaki, (1)

    International Nuclear Information System (INIS)

    All large hospitals and 40% of the small hospitals and clinics in Hiroshima and Nagasaki cities were surveyed for the X-ray examinations they performed during a 2-week period in 1974. The frequency and type of X-ray examinations received by members of the RERF Adult Health Study (AHS) and the RERF Life Span Study (LSS) extended, excluding AHS (Non-AHS), were compared with the general population in each city. Radiologic exposures of patients at hospitals and clinics were most frequent among the general populations. The number of patients, examinations, and exposures per caput per year in each population were estimated. Since the age distribution differed among the three populations, comparisons were made only after correcting for age. On a per caput per year basis exposure frequency was relatively high in the AHS and low in the general populations, a reflection of the greater number of patients in the AHS than in the general populations. Non-AHS males in Nagasaki had a higher X-ray examination rate than did the AHS subjects. The others in the Non-AHS did not differ appreciably from the general populations. There was no difference among these groups according to body sites examined. (author)

  20. Clinical evaluation of radionuclide cisternography and x-ray CT in normal pressure hydrocephalus

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Osamu; Maeda, Toshio; Matsuda, Hiroshi; Ishida, Hiroko; Michigishi, Takatoshi (Kanazawa Univ. (Japan). School of Medicine)

    1983-06-01

    The retrospective reevaluation of the radionuclide cisternogram and X-ray CT were studied in 14 cases in whom cerebrospinal fluid shunt were installed under the diagnosis of normal pressure hydrocephalus after these examinations. Only half of these cases showed clinical improvement after shunt operation. The most reliable finding of the cisternography was the persistent ventricular visualization with bilateral block at subarachnoid space on 48 hour image. These findings were observed in seven cases, and all of them but one case showed clinical improvement after shunt installation. The exceptional one case in whom shunt was not effective. The cisternogram of the other case whose shunt was effective showed the transient ventricular visualization upto 24 hour, the unilateral subarachnoidal space block upto 48 hour and the prominently delayed clearance of radionuclide from the head. The cisternographic findings of the delayed radionuclide clearance and the ventricular visualization on 24 hour-image were insufficient to help the shunt effect. The most hopeful findings of the X-ray CT was the poor-visualization of Sylvian fissure at least on two cross sections. These findings were observed in eight cases, and six out of them showed clinical improvement after shunt operation. But the poor-visualization of Sylvian fissure is not a specific sign for normal pressure hydrocephalus. We concluded that the abnormal findings on 48 hour-image of cisternography are correlated well with the effect of cerebrospinal fluid shunt in normal pressure hydrocephalus, and the cisternography is still very useful in the chosen patients with clinical and X-ray CT findings.

  1. Clinical applications of total reflection X-Ray Fluorescence in the treatment of cancer, Preliminary results

    International Nuclear Information System (INIS)

    A simple procedure is presents in which direct irradiation of small (10 ?l) quantities of blood serum, without chemical treatment or internal standard addition, allows reliable quantification of the PT plasma level with a 300 ppb detection limit and precision of 7% (n=7) It is shown that the method allows determination of the time evolution of the drug concentration and the drug half life in the patient the results indicated the viability of an improvement in the clinical practice of chemotherapy by the routine analysis of platinum with total reflection X-Ray Fluorescence

  2. Clinical importance of digitized chest X-ray for detection of pulmonary infiltrations in bone marrow transplant patients during aplasia

    International Nuclear Information System (INIS)

    Purpose: Evaluation of digitized chest X-ray for the detection of pulmonary infiltrations in bone marrow transplant patients during aplasia. Methods: Digitized chest X-rays of 40 patients (21 female, 19 male) with 'Fever of unknown origin' (FUO) were evaluated concerning radiological signs of pulmonary infiltrations and correlated to clinical findings, blood chemistry, microbiology and bronchoscopy. Additionally, an individual risk profile was established. Results: In 11/40 patients pulmonary infiltrations were detected in digitized chest X-rays (group 1). 10/11 developed an infectious pulmonary infiltration. 29/40 patients developed no pulmonary infiltration (group 2). When fever increased for the first time (initial chest X-ray) a sensitivity, specificity, positive and negative predictive value of 46%, 86%, 56%, 81% and for the chest X-rays in process of 61%, 79%, 68% and 73% was found. C-reactive protein and temperature increase occured statistically significantly earlier (p<0.05) in group 1 compared to group 2. The average latency of digital chest X-rays in comparison to c-reactive protein and temperature increase was 6 days. The incidence of risk factors was significantly higher in group 1 in comparison to group 2 (p<0.05). Conclusion: Digitized chest X-rays are not a reliable method for primary detection of pulmonary infiltrations after bone marrow transplantation. Individual risk factors have to be taken into consideration to indicate further diagnostic methods such as computed tomography at an earlier time. (orig.)

  3. A simple and fast physics-based analytical method to calculate therapeutic and stray doses from external beam, megavoltage x-ray therapy.

    Science.gov (United States)

    Jagetic, Lydia J; Newhauser, Wayne D

    2015-06-21

    State-of-the-art radiotherapy treatment planning systems provide reliable estimates of the therapeutic radiation but are known to underestimate or neglect the stray radiation exposures. Most commonly, stray radiation exposures are reconstructed using empirical formulas or lookup tables. The purpose of this study was to develop the basic physics of a model capable of calculating the total absorbed dose both inside and outside of the therapeutic radiation beam for external beam photon therapy. The model was developed using measurements of total absorbed dose in a water-box phantom from a 6 MV medical linear accelerator to calculate dose profiles in both the in-plane and cross-plane direction for a variety of square field sizes and depths in water. The water-box phantom facilitated development of the basic physical aspects of the model. RMS discrepancies between measured and calculated total absorbed dose values in water were less than 9.3% for all fields studied. Computation times for 10 million dose points within a homogeneous phantom were approximately 4 min. These results suggest that the basic physics of the model are sufficiently simple, fast, and accurate to serve as a foundation for a variety of clinical and research applications, some of which may require that the model be extended or simplified based on the needs of the user. A potentially important advantage of a physics-based approach is that the model is more readily adaptable to a wide variety of treatment units and treatment techniques than with empirical models.

  4. Phase-contrast x-ray imaging of the breast: recent developments towards clinics

    Science.gov (United States)

    Coan, P.; Bravin, A.; Tromba, G.

    2013-12-01

    Breast imaging is one of the most demanding and delicate radiological applications. Mammography is the primary diagnosis tool in breast cancer detection and national screening programmes. Recognition of breast cancer depends on the detection of subtle architectural distortion, masses showing near normal breast tissue density, skin thickening and microcalcifications. The small differences in attenuation of x-rays between normal and malignant tissue result in low contrast and make cancer detection difficult in conventional x-ray absorption mammography. Because of these challenging aspects, breast imaging has been the first and most explored diagnostic field in phase-contrast imaging research. This novel imaging method has been extensively used and has demonstrated a unique capability in producing high-contrast and sensitive images at quasi-histological resolution. The most recent and significant technical developments are introduced and results obtained by the application of various phase-contrast imaging techniques for breast imaging are reported. The first phase-contrast mammography clinical trials project is also presented and the short- and long-term future perspectives of the method are discussed.

  5. The clinical value of X-ray images of the teeth and jaws

    Science.gov (United States)

    Brocklebank, Laetitia

    2003-08-01

    X-ray images of the teeth and jaws are required for a variety of diagnostic purposes to supplement a clinical examination, and are invaluable for providing pictorial information about the structures that cannot be examined with direct vision. They can be acquired using traditional film systems which produce analogue images, or using a variety of alternative image receptors which result in a digital image. Irrespective of the method of image acquisition they are utilised by the dental surgeon in order to benefit their patients' management. Numerous disease processes can affect the teeth and jaws, in addition to a range of developmental abnormalities. These can be classified according to a radiological sieve, which also includes artefactual and iatrogenic features. The key components of the classification are: developmental, inflammatory, traumatic, cystic, neoplastic, osteodystrophies and systemic disorders. This paper will utilise examples of radiographic images of patients to illustrate components of this classification which are unique to the teeth and jaws.

  6. X-ray physics- and bone composition-based estimation of thickness characteristics from clinical mandibular radiographs.

    Science.gov (United States)

    Scheiner, Stefan; Hellmich, Christian; Müller, Christoph; Bonitz, Lars; Kober, Cornelia

    2015-10-01

    In dentistry, clinical radiographs (also called X-ray images) reflect the intensity loss of an X-ray when being transmitted through the mandibular objects, and this loss is quantified in terms of grey values. While such images are standardly used for pathology detection by the experienced dentist, we here present a new method for getting more quantitative information out of such 2D radiographs, "extending" them into the third dimension. This "extension" requires consistent combination of X-ray physics (namely, X-ray intensity loss quantification along paths orthogonal to the panoramic clinical image and X-ray attenuation averaging for composite materials) with anatomically known upper and lower limits of vascular porosities in cortical and trabecular bone compartments. Correspondingly computed ranges of overall organ thicknesses are extremely narrow, suggesting adequate estimation of thickness characteristics from 2D radiographic panoramas used clinically, while predicted cortical and trabecular thickness ranges vary by ±8.47% and ±16.13%, respectively. The proposed method also identifies variations between thicknesses at similar anatomical locations left and right of the face's symmetry axis, and molar regions turn out to be thicker than those close to incisors. This paves the way to more detailed diagnostic activities, e.g. in combination with Finite Element simulations.

  7. Nanoscale radiation transport and clinical beam modeling for gold nanoparticle dose enhanced radiotherapy (GNPT) using X-rays.

    Science.gov (United States)

    Zygmanski, Piotr; Sajo, Erno

    2016-01-01

    We review radiation transport and clinical beam modelling for gold nanoparticle dose-enhanced radiotherapy using X-rays. We focus on the nanoscale radiation transport and its relation to macroscopic dosimetry for monoenergetic and clinical beams. Among other aspects, we discuss Monte Carlo and deterministic methods and their applications to predicting dose enhancement using various metrics.

  8. Assessment of setup error in orthogonal megavoltage X-ray film for whole breast radiation with breast bracket immobilized%乳腺托架固定下全乳调强放疗摆位误差兆伏X线验证平片测定分析

    Institute of Scientific and Technical Information of China (English)

    王健仰; 王淑莲; 黄鹏; 张涛; 李晔雄; 金晶; 王维虎; 刘新帆; 余子豪

    2013-01-01

    目的 用兆伏(MV)X线平片测定乳腺托架固定下全乳放疗摆位误差,探讨自由呼吸状态下临床靶体积(CTV)外扩至计划靶体积(PTV)的边界.方法 选取2010-2012年本科行保乳术后调强放疗的29例乳腺癌患者,其中17例行全乳照射,12例行全乳和锁骨上淋巴引流区照射.均采用乳腺托架体位固定,利用放疗计划系统数字重建图像与治疗期间拍摄正交MV验证平片比较,确定摆位误差.对接受锁骨上淋巴引流区照射与未照射的误差比较行成组t检验.结果 全体患者共获得正交MV验证平片图像127套,平均每人(4.4±1.2)套.全组患者左右、上下、前后方向摆位误差分别为(0.9±3.1)、(0.7±3.0)、(1.2±2.1)mm,摆位误差的系统误差分别为3.1、3.0、2.1 mm,随机误差分别为2.7、3.3、3.5 mm;做与未做锁骨上淋巴引流区照射者的摆位误差无差异(t=0.02、0.20、0.20,P=0.98、0.85、0.85).CTV至PTV边界左右、上下、前后方向分别为9.6、9.8、7.7 mm.结论 用乳腺托架固定全乳调强放疗的CTV外放PTV在左右、上下、前后方向上应至少分别为9.6、9.8、7.7 mm.%Objective To quantify the setup errors measured with orthogonal megavoltage X-ray film in breast cancer patients immobilized in breast bracket.To probe into the margins from clinical target volume (CTV) to planning target volume (PTV) in 3 directions.Methods Repeat orthogonal megavoltage X-ray films were acquired for routine of fine setup verification in 29 breast cancer patients after conserving surgery,17 received whole breast radiation and 12 received both whole breast and supraclavicular node radiation.All patients were immobilized in the supine position with both arms raised over their heads,using a personalized α-cradle (breast bracket).Registrations of the bony anatomy for megavoltage X-ray films to digitally reconstructed-radiographs from the planning CT were compared.Systematic and random setup errors were quantified

  9. 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.

  10. Pediatric dual-energy X-ray absorptiometry: interpretation and clinical and research application

    Directory of Open Access Journals (Sweden)

    Jung Sub Lim

    2010-03-01

    Full Text Available Peak bone mass is established predominately during childhood and adolescence. It is an important determinant of future resistance to osteoporosis and fractures to gain bone mass during growth. The issue of low bone density in children and adolescents has recently attracted much attention and the use of pediatric dual-energy X-ray absorptiometry (DXA is increasing. The process of interpretation of pediatric DXA results is different from that of adults because normal bone mineral density (BMD of children varies by age, body size, pubertal stage, skeletal maturation, sex, and ethnicity. Thus, an appropriate normal BMD Z-score reference value with Z-score should be used to detect and manage low BMD. Z-scores below -2.0 are generally considered a low BMD to pediatrician even though diagnoses of osteoporosis in children and adolescents are usually only made in the presence of at least one fragility fracture. This article will review the basic knowledge and practical guidelines on pediatric DXA based on the International Society for Clinical Densitometry (ISCD Pediatric Official Positions. Also discussed are the characteristics of normal Korean children and adolescents with respect to BMD development. The objective of this review is to help pediatricians to understand when DXA will be useful and how to interpret pediatric DXA reports in the clinical practice for management of children with the potential to develop osteoporosis in adulthood.

  11. Clinical applications of scanning electron microscopy and energy dispersive X-ray analysis in dermatology--an up-date

    International Nuclear Information System (INIS)

    Dermatological papers comprising scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis data published 1983 through 1986 in international journals are reviewed, as an update to our 1984 paper on Clinical applications of scanning electron microscopy and X-ray microanalysis in dermatology. The present paper not only deals with a review of recent publications in this area but also presents the application of microincineration to hair and cryosectioned freeze-dried skin specimens. Examples of the increased contrast obtained in hair cross sections are presented and a discussion on the feasibility of microincineration at analysis of hair and skin cross sections is given. Particle probe analysis (EDX: energy dispersive X-ray analysis and PMP: proton microprobe analysis) as applied to hair and skin samples are presented with stress put on the proton probe analysis. The complementarity of EDX and PMP is demonstrated and future applications are suggested. 75 references

  12. Clinical studies on health conditions of medical diagnostic X-ray workers

    Energy Technology Data Exchange (ETDEWEB)

    Liu Liqun

    1984-10-01

    The results of investigations on general health conditions of 2484 medical X-ray workers and 1718 controls were reported. It was shown that the incidences of neurasthenic syndrome, loss of appetite, baldness etc. in X-ray workers were statistically higher than those in controls. Chronic rhinitis, pharyngitis, and paranasal sinusitis also occurred more frequently in the former group. The blood pressure, pulse rate, capillary resistance and past medical history showed no significant difference between these two groups. (Author).

  13. Characterization of a Test for Invasive Breast Cancer Using X-ray Diffraction of Hair - Results of a Clinical Trial

    Directory of Open Access Journals (Sweden)

    Gary L. Corino

    2009-11-01

    Full Text Available Objective: To assess the performance of a test for breast cancer utilizing synchrotron x-ray diffraction analysis of scalp hair from women undergoing diagnostic radiology assessment. Design and Setting: A double-blinded clinical trial of women who attended diagnostic radiology clinics in Australia. Patients: 1796 women referred for diagnostic radiology, with no previous history of cancer. Main Outcome Measures: Sensitivity, specificity and accuracy of the hair test analysis compared to the gold standard of imaging followed by biopsy where indicated. Results: The hair-based assay had an overall accuracy of >77% and a negative predictive value of 99%. For all women, the sensitivity of both mammography and x-ray diffraction alone was 64%, but when used together the sensitivity rose to 86%. The sensitivity of the hair test for women under the age of 70 was 74%. Conclusion: In this large population trial the association between the presence of breast cancer and an altered hair fibre X-ray diffraction pattern previously reported has been confirmed. It appears that mammography and X-ray diffraction of hair detect different populations of breast cancers, and are synergistic when used together.

  14. Clinics, regulatory inspections and regulations concerning the use of soft X-rays and HDRs

    International Nuclear Information System (INIS)

    The medical use of soft X-ray and brachytherapy equipment, in Brazil, is analysed following norms, standards and recommendations from the National Nuclear Energy Commission (CNEN), the Health Ministry (MS), the Institute of Radioprotection and Dosimetry (IRD), the National Institute of Metrology, Normalisation and Industrial Quality (INMETRO), the National Laboratory of Ionising Radiation Metrology (LNMRI), the Brazilian Association of Medical Physics (ABFM), the Brazilian Association of Technical Norms (ABNT) and the International Atomic Energy Agency (IAEA). The present analysis shows that CNEN's and MS's regulations do not cover soft X-ray equipment, that normative inspections carried out by IRD do not include HDR and soft X-ray dosimetry, LNMRI - assigned by INMETRO as the reference laboratory for ionising radiation metrology - does not calibrate dosemeters for brachytherapy, ABNT does not adopt quantities and dose limits standardised by CNEN, ABFM bases its recommendations on bibliographic references where the standard quantities are not among LNMRI standards and IAEA recommends procedures for soft X-ray dosimetry that have been criticised in the literature. It is thus concluded that there is no formal control over the use of soft X-ray and HDR equipment, and that existing regulations are not sufficient for what it is expected of their utilisation in the treatment of malignant tumours. (author)

  15. Interlaced X-ray Microplanar Beams: A Radiosurgery Approach with Clinical Potential

    Energy Technology Data Exchange (ETDEWEB)

    Dilimanian,F.; Zhong, Z.; Bacarian, T.; Benveniste, H.; Romanelli, P.; Wang, R.; Welwart, J.; Yuasa, T.; Rosen, E.; Anschel, D.

    2006-01-01

    Studies have shown that x-rays delivered as arrays of parallel microplanar beams (microbeams), 25- to 90-{micro}m thick and spaced 100-300 {micro}m on-center, respectively, spare normal tissues including the central nervous system (CNS) and preferentially damage tumors. However, such thin microbeams can only be produced by synchrotron sources and have other practical limitations to clinical implementation. To approach this problem, we first studied CNS tolerance to much thicker beams. Three of four rats whose spinal cords were exposed transaxially to four 400-Gy, 0.68-mm microbeams, spaced 4 mm, and all four rats irradiated to their brains with large, 170-Gy arrays of such beams spaced 1.36 mm, all observed for 7 months, showed no paralysis or behavioral changes. We then used an interlacing geometry in which two such arrays at a 90 deg angle produced the equivalent of a contiguous beam in the target volume only. By using this approach, we produced 90-, 120-, and 150-Gy 3.4 x 3.4 x 3.4 mm3 exposures in the rat brain. MRIs performed 6 months later revealed focal damage within the target volume at the 120- and 150-Gy doses but no apparent damage elsewhere at 120 Gy. Monte Carlo calculations indicated a 30-{micro}{micro}m dose falloff (80-20%) at the edge of the target, which is much less than the 2- to 5-mm value for conventional radiotherapy and radiosurgery. These findings strongly suggest potential application of interlaced microbeams to treat tumors or to ablate nontumorous abnormalities with minimal damage to surrounding normal tissue.

  16. Interlaced X-ray Microplanar Beams: A Radiosurgery Approach with Clinical Potential

    International Nuclear Information System (INIS)

    Studies have shown that x-rays delivered as arrays of parallel microplanar beams (microbeams), 25- to 90-(micro)m thick and spaced 100-300 (micro)m on-center, respectively, spare normal tissues including the central nervous system (CNS) and preferentially damage tumors. However, such thin microbeams can only be produced by synchrotron sources and have other practical limitations to clinical implementation. To approach this problem, we first studied CNS tolerance to much thicker beams. Three of four rats whose spinal cords were exposed transaxially to four 400-Gy, 0.68-mm microbeams, spaced 4 mm, and all four rats irradiated to their brains with large, 170-Gy arrays of such beams spaced 1.36 mm, all observed for 7 months, showed no paralysis or behavioral changes. We then used an interlacing geometry in which two such arrays at a 90 deg angle produced the equivalent of a contiguous beam in the target volume only. By using this approach, we produced 90-, 120-, and 150-Gy 3.4 x 3.4 x 3.4 mm3 exposures in the rat brain. MRIs performed 6 months later revealed focal damage within the target volume at the 120- and 150-Gy doses but no apparent damage elsewhere at 120 Gy. Monte Carlo calculations indicated a 30-(micro)(micro)m dose falloff (80-20%) at the edge of the target, which is much less than the 2- to 5-mm value for conventional radiotherapy and radiosurgery. These findings strongly suggest potential application of interlaced microbeams to treat tumors or to ablate nontumorous abnormalities with minimal damage to surrounding normal tissue

  17. Chest X-rays and associated clinical parameters in pulmonary Tubercolosis cases from the National Tubercolosis Program, Mumbai, India

    Directory of Open Access Journals (Sweden)

    Yatin N. Dholakia

    2012-01-01

    Full Text Available The study was carried out in pulmonary tuberculosis (PTB patients from the local Tuberculosis control programme, Mumbai, India. It examined features of chest X-rays and their correlation with clinical parameters for possible application in suspected multidrug resistant TB (MDRTB and to predict outcome in new and treatment failure PTB cases. X-ray features (infiltrate, cavitation, miliary shadows, pleural effusion, mediastinal lymphadenopathy and extent of lesions were analyzed to identify associations with biological/clinical parameters through univariate and multivariate logistic regression. Failures demonstrated associations between extensive lesions and high glycosylated hemoglobin (GHb levels (P=0.028 and male gender (P=0.03. An association was also detected between cavitation and MDR (P=0.048. In new cases, bilateral cavities were associated with MDR (P=0.018 and male gender (P=0.01, low body mass index with infiltrates (P=0.008, and smoking with cavitation (P=0.0238. Strains belonging to the Manu1 spoligotype were associated with mild lesions (P=0.002. Poor outcome showed borderline significance with extensive lesions at onset (P=0.053. Furthermore, amongst new cases, smoking, the Central Asian Strain (CAS spoligotype and high GHb were associated with cavitation, whereas only CAS spoligotypes and high GHb were associated with extensive lesions. The study highlighted associations between certain clinical parameters and X-ray evidence which support the potential of X-rays to predict TB, MDRTB and poor outcome. The use of Xrays as an additional tool to shorten diagnostic delay and shortlist MDR suspects amongst nonresponders to TB treatment should be explored in a setting with limited resources coping with a high MDR case load such as Mumbai.

  18. Investigation of clinical conditions affecting quality control in a dental X-ray unit

    International Nuclear Information System (INIS)

    In this study, to clarify quality control issues in a dental X-ray unit, we surveyed the uniformity and safety of absorbed doses and exposure time from dental X-ray units, and evaluated image quality of intraoral radiography at Osaka Dental University Hospital. Measurements of dose and exposure time were carried out five times and the mean was calculated at twenty-two dental X-ray units in our university hospital using the standard parameters for the mandibular molar region in adults. Intraoral radiography for evaluation of image quality was taken using D-speed films under the standard parameters for the mandibular molar region in adults and E-speed films for pediatric patients. Evaluation of image quality was performed by three oral radiologists. Dose and exposure time differed significantly among units. Image quality of intraoral radiography using D-speed films was not significantly better than that of E-speed films. This study demonstrated that it is necessary to establish a uniform dose and exposure time and to change D-speed films to E-speed films when obtaining intraoral radiography in our hospital. (author)

  19. Tomographic x-ray guided three-dimensional diffuse optical imaging of osteoarthritis in the finger joints: a clinical study

    Science.gov (United States)

    Yuan, Zhen; Jiang, Huizhu; Zhang, Qizhi; Sobel, Eric S.; Jiang, Huabei

    2009-02-01

    To investigate the typical optical findings that can be used to characterize osteoarthritis, the distal interphalangeal finger joints from 40 subjects including 22 patients and 18 healthy controllers were examined clinically and scanned by a novel hybrid imaging system. The hybrid imaging platform integrated a C-arm based x-ray tomosynthetic system with a multi-channel optic-fiber based diffuse optical imaging system. Optical images were recovered qualitatively and quantitatively based on a regularization-based reconstruction algorithm that can incorporate the fine structural maps obtained from x-ray as a priori spatial information into diffuse optical tomography reconstruction procedures. Our findings suggest statistically significant differences between healthy and osteoarthritis finger joints. X-ray guided diffuse optical imaging may not only detect radiologic features supporting the development of an inflammatory disorder but may also help discriminate specific optical features that differ between osteoarthritic and healthy joints. These quantitative optical features are also potentially important for a better understanding of inflammatory arthritis in humans.

  20. 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.

    Science.gov (United States)

    Hambali, Ahmad Shariff; Ng, Kwan-Hoong; Abdullah, Basri Johan Jeet; Wang, Hwee-Beng; Jamal, Noriah; Spelic, David C; Suleiman, Orhan 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.

  1. 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)

    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)

  2. Dual-Energy X-Ray Performs as Well as Clinical Computed Tomography for the Measurement of Visceral Fat

    OpenAIRE

    Micklesfield, Lisa K.; Goedecke, Julia H.; Punyanitya, Mark; Kevin E Wilson; Kelly, Thomas L.

    2012-01-01

    Visceral adipose tissue (VAT) is associated with adverse health effects including cardiovascular disease and type 2 diabetes. We developed a dual-energy X-ray absorptiometry (DXA) measurement of visceral adipose tissue (DXA-VAT) as a low cost and low radiation alternative to computed tomography (CT). DXA-VAT was compared to VAT assessed using CT by an expert reader (E-VAT). In addition, the same CT slice was also read by a clinical radiographer (C-VAT) and a best-fit anthropomorphic and demog...

  3. Clinical applications of scanning electron microscopy and X-ray microanalysis in dermatology

    International Nuclear Information System (INIS)

    Scanning electron microscopy is frequently applied to dermatological problems, as is evident from a review of the recent literature. In this paper, preparation methods and new techniques allowing experimental studies on the integumentary system are emphasized. Quantitative analysis in the electron microscope by use of energy-dispersive X-ray microanalysis (EDX) has become an important accessory technique. EDX can, for instance, be used to study problems involving physiological changes induced in skin by agents causing contact reactions. Recently, it has been shown that treatment with DNCB, chromate and nickel causes changes in elemental distribution in guinea-pig skin. In addition, elemental uptake in the integumentary system and in pathological inclusions in skin can be analyzed

  4. Evaluation of a new low-dose digital X-ray device: first dosimetric and clinical results in children

    International Nuclear Information System (INIS)

    Background. A new low-dose digital X-ray device, based on Charpak's Nobel prize-winning multiwire chamber, enables the production of images at very low doses. Objectives. To present the first dosimetric and clinical results. Materials and methods. The analysis was performed on 93 children with scoliosis and 47 undergoing pelvic radiography. The comparative study between conventional X-ray and the new technique focused on three points: (1) the dose delivered by each system (2) the diagnostic information provided by each system and (3) comparison of image quality criteria with European guidelines. Results. The mean ratio of conventional dose to that of the low-dose technique was 13.1 for the spinal examination and 18.8 for the pelvis. There was no significant difference in diagnostic information available from each modality, but there was a slight difference in quality criteria in favour of the conventional technique. Conclusion. This new device allows spectacular dose reduction, consistent with adequate clinical information. Improvements of the prototype will lead to extension of potential indications and industrial development. (orig.)

  5. Comparison of the responses of TLD-100 and radiochromic films exposed to X-rays of low energy in a radiodiagnostic clinical treatment

    Energy Technology Data Exchange (ETDEWEB)

    Castro, M.; Mesa, F.; Sosa, M. [Physics Institute, University of Guanajuato, Loma del Bosque 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico)

    2007-07-01

    Full text: In this work a comparison of the responses of a TLD-100 and a radiochromic film exposed to a low energy X-ray beam is presented. X-rays in the range of 20 to 120 KV from a clinical machine at the radiodiagnostic unit of the IMSS-Tl hospital in Leon were used. The processes of calibration of both the TLD-100 and the radiochromic films are also discussed. (Author)

  6. Evaluation of the results of a clinical study of X-ray specific activity of bilimin, a soviet radiopaque agent for oral cholecystography and cholecystoangiography

    International Nuclear Information System (INIS)

    The results of a clinical study of bilimin, a drug for oral X-ray examination of the bile tract are analysed. A good X-ray-specific activity of bilim which was no worse in contrast tnan identical foreign agents is emphasized. Among side-effects were short-term dyspepsia than disappeared without treatment. A conclusion has been made of a high diagnostic value and safety of bilimin

  7. Structural considerations for the practical development of primary shielding of X-ray rooms of megavoltage; Consideracoes estruturais para o desenvolvimento pratico da blindagem primaria de salas de raios-x de megavoltagem

    Energy Technology Data Exchange (ETDEWEB)

    Lava, Deise D.; Borges, Diogo da S.; Affonso, Renato R.W.; Moreira, Maria de L.; Guimaraes, Antonio C.F., E-mail: deise_dy@hotmail.com, E-mail: diogosb@outlook.com, E-mail: raoniwa@yahoo.com.br, E-mail: malu@ien.gov.br, E-mail: tony@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    Due to the necessity of the use of accelerators with voltages above 10 MV in medical facilities, becomes necessary to evaluate the efficiency of the thickness of shielding materials used in rooms that contain these devices. This work presents the development of an algorithm able to provide data in a practical way, regarding the thickness of materials that can be used for an effective shielding against primary beams from these equipment. The use of the computer language C ++ allowed developing a practical tool for determining the thickness of materials required to protect the public and Individuals Occupationally Exposed (IOEs) against major powers beams. Furthermore, it was considered by calculations Intensity Modulated Radiotherapy Technique (IMRT). The construction of this tool was based to ensure the dose limits established in the CNEN-NN-3.01. The dose limiting is done through the use of loops able to validate the efficiency of thickness determined by the algorithm itself, and ensure if the radiation dose exceeds the limits set by the standard, it will be the inclusion of sufficient Half-Reducer Layers in so that the dose is within the parameters established by the Brazilian National Nuclear Energy Commission (CNEN). The code validation is performed by comparing results obtained in the examples p recalculated in the NCRP Report-151 (Structural Shielding Design and Evaluation for megavoltage X and Gamma-Ray Radiotherapy Facilities) with the results generated by the code. The results are satisfactory and consistent with that report.

  8. X-Rays

    Science.gov (United States)

    X-rays are a type of radiation called electromagnetic waves. X-ray imaging creates pictures of the inside of ... different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat ...

  9. Dual energy x-ray imaging and scoring of coronary calcium: physics-based digital phantom and clinical studies

    Science.gov (United States)

    Zhou, Bo; Wen, Di; Nye, Katelyn; Gilkeson, Robert C.; Wilson, David L.

    2016-03-01

    Coronary artery calcification (CAC) as assessed with CT calcium score is the best biomarker of coronary artery disease. Dual energy x-ray provides an inexpensive, low radiation-dose alternative. A two shot system (GE Revolution-XRd) is used, raw images are processed with a custom algorithm, and a coronary calcium image (DECCI) is created, similar to the bone image, but optimized for CAC visualization, not lung visualization. In this report, we developed a physicsbased, digital-phantom containing heart, lung, CAC, spine, ribs, pulmonary artery, and adipose elements, examined effects on DECCI, suggested physics-inspired algorithms to improve CAC contrast, and evaluated the correlation between CT calcium scores and a proposed DE calcium score. In simulation experiment, Beam hardening from increasing adipose thickness (2cm to 8cm) reduced Cg by 19% and 27% in 120kVp and 60kVp images, but only reduced Cg by <7% in DECCI. If a pulmonary artery moves or pulsates with blood filling between exposures, it can give rise to a significantly confounding PA signal in DECCI similar in amplitude to CAC. Observations suggest modifications to DECCI processing, which can further improve CAC contrast by a factor of 2 in clinical exams. The DE score had the best correlation with "CT mass score" among three commonly used CT scores. Results suggest that DE x-ray is a promising tool for imaging and scoring CAC, and there still remains opportunity for further DECCI processing improvements.

  10. Soft tissue visualization using a highly efficient megavoltage cone beam CT imaging system

    Science.gov (United States)

    Ghelmansarai, Farhad A.; Bani-Hashemi, Ali; Pouliot, Jean; Calderon, Ed; Hernandez, Paco; Mitschke, Matthias; Aubin, Michelle; Bucci, Kara

    2005-04-01

    Recent developments in two-dimensional x-ray detector technology have made volumetric Cone Beam CT (CBCT) a feasible approach for integration with conventional medical linear accelerators. The requirements of a robust image guidance system for radiation therapy include the challenging combination of soft tissue sensitivity with clinically reasonable doses. The low contrast objects may not be perceptible with MV energies due to the relatively poor signal to noise ratio (SNR) performance. We have developed an imaging system that is optimized for MV and can acquire Megavoltage CBCT images containing soft tissue contrast using a 6MV x-ray beam. This system is capable of resolving relative electron density as low as 1% with clinically acceptable radiation doses. There are many factors such as image noise, x-ray scatter, improper calibration and acquisitions that have a profound effect on the imaging performance of CBCT and in this study attempts were made to optimize these factors in order to maximize the SNR. A QC-3V phantom was used to determine the contrast to noise ratio (CNR) and f50 of a single 2-D projection. The computed f50 was 0.43 lp/mm and the CNR for a radiation dose of 0.02cGy was 43. Clinical Megavoltage CBCT images acquired with this system demonstrate that anatomical structures such as the prostate in a relatively large size patient are visible using radiation doses in range of 6 to 8cGy.

  11. 数字乳腺X线机与传统乳腺X线机的临床分析探讨%The Clinical Analysis of Digital Breast X-ray Machine and Traditional Breast X-ray Machine

    Institute of Scientific and Technical Information of China (English)

    马秋伟

    2014-01-01

    目的:比较数字乳腺X线机与传统乳腺X线机的临床应用效果。方法:收集2009年11月-2013年11月笔者所在医院收治的90例乳腺癌患者的临床资料,并进行回顾性分析。根据不同的诊断方法,将患者分为两组,每组45例。其中将采用传统乳腺X线机诊断的患者作为对照组,把采用数字乳腺X线机进行诊断的患者作为观察组,对比两组的检查时长、曝光次数、摄影体位。结果:两组患者检查时长、曝光次数、摄影体位比较,差异有统计学意义(P<0.05)。结论:数字乳腺X线机具备曝光条件好、成像清晰等特点,有利于缩短检查时长。%Objective:To compare the clinical application effect of digital breast X-ray machine and traditional breast X-ray machine.Method:The clinical data of 90 cases of breast cancer patients in author’s hospital from November 2009 to November 2013 were retrospectively analyzed.According to the different diagnosis method,the patients were divided into two groups,each group consisting of 45 cases.The patients with the traditional breast X-ray machine diagnosis as a control group,the patients with digital breast X-ray machine diagnosis as the observation group,the inspection time,exposure times,photography posture of two groups were compared.Result:The differences of inspection time,exposure times,photography posture between two groups had statistical significance(P<0.05).Conclusion:Digital breast X-ray machine with exposure conditions is good,has clear imaging and so on,can shorten the examination time.

  12. SU-E-T-50: Automatic Validation of Megavoltage Beams Modeled for Clinical Use in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Melchior, M [Terapia Radiante S.A., La Plata, Buenos Aires (Argentina); Salinas Aranda, F [Vidt Centro Medico, Ciudad Autonoma De Buenos Aires (Argentina); 21st Century Oncology, Ft. Myers, FL (United States); Sciutto, S [Universidad Nacional de La Plata, La Plata, Buenos Aires (Argentina); Dodat, D [Centro Medico Privado Dean Funes, La Plata, Buenos Aires (Argentina); Larragueta, N [Universidad Nacional de La Plata, La Plata, Buenos Aires (Argentina); Centro Medico Privado Dean Funes, La Plata, Buenos Aires (Argentina)

    2014-06-01

    Purpose: To automatically validate megavoltage beams modeled in XiO™ 4.50 (Elekta, Stockholm, Sweden) and Varian Eclipse™ Treatment Planning Systems (TPS) (Varian Associates, Palo Alto, CA, USA), reducing validation time before beam-on for clinical use. Methods: A software application that can automatically read and analyze DICOM RT Dose and W2CAD files was developed using MatLab integrated development environment.TPS calculated dose distributions, in DICOM RT Dose format, and dose values measured in different Varian Clinac beams, in W2CAD format, were compared. Experimental beam data used were those acquired for beam commissioning, collected on a water phantom with a 2D automatic beam scanning system.Two methods were chosen to evaluate dose distributions fitting: gamma analysis and point tests described in Appendix E of IAEA TECDOC-1583. Depth dose curves and beam profiles were evaluated for both open and wedged beams. Tolerance parameters chosen for gamma analysis are 3% and 3 mm dose and distance, respectively.Absolute dose was measured independently at points proposed in Appendix E of TECDOC-1583 to validate software results. Results: TPS calculated depth dose distributions agree with measured beam data under fixed precision values at all depths analyzed. Measured beam dose profiles match TPS calculated doses with high accuracy in both open and wedged beams. Depth and profile dose distributions fitting analysis show gamma values < 1. Relative errors at points proposed in Appendix E of TECDOC-1583 meet therein recommended tolerances.Independent absolute dose measurements at points proposed in Appendix E of TECDOC-1583 confirm software results. Conclusion: Automatic validation of megavoltage beams modeled for their use in the clinic was accomplished. The software tool developed proved efficient, giving users a convenient and reliable environment to decide whether to accept or not a beam model for clinical use. Validation time before beam-on for clinical use

  13. SU-E-T-50: Automatic Validation of Megavoltage Beams Modeled for Clinical Use in Radiation Therapy

    International Nuclear Information System (INIS)

    Purpose: To automatically validate megavoltage beams modeled in XiO™ 4.50 (Elekta, Stockholm, Sweden) and Varian Eclipse™ Treatment Planning Systems (TPS) (Varian Associates, Palo Alto, CA, USA), reducing validation time before beam-on for clinical use. Methods: A software application that can automatically read and analyze DICOM RT Dose and W2CAD files was developed using MatLab integrated development environment.TPS calculated dose distributions, in DICOM RT Dose format, and dose values measured in different Varian Clinac beams, in W2CAD format, were compared. Experimental beam data used were those acquired for beam commissioning, collected on a water phantom with a 2D automatic beam scanning system.Two methods were chosen to evaluate dose distributions fitting: gamma analysis and point tests described in Appendix E of IAEA TECDOC-1583. Depth dose curves and beam profiles were evaluated for both open and wedged beams. Tolerance parameters chosen for gamma analysis are 3% and 3 mm dose and distance, respectively.Absolute dose was measured independently at points proposed in Appendix E of TECDOC-1583 to validate software results. Results: TPS calculated depth dose distributions agree with measured beam data under fixed precision values at all depths analyzed. Measured beam dose profiles match TPS calculated doses with high accuracy in both open and wedged beams. Depth and profile dose distributions fitting analysis show gamma values < 1. Relative errors at points proposed in Appendix E of TECDOC-1583 meet therein recommended tolerances.Independent absolute dose measurements at points proposed in Appendix E of TECDOC-1583 confirm software results. Conclusion: Automatic validation of megavoltage beams modeled for their use in the clinic was accomplished. The software tool developed proved efficient, giving users a convenient and reliable environment to decide whether to accept or not a beam model for clinical use. Validation time before beam-on for clinical use

  14. Chest x-ray

    Science.gov (United States)

    Chest radiography; Serial chest x-ray; X-ray - chest ... You stand in front of the x-ray machine. You will be told to hold your breath when the x-ray is taken. Two images are usually taken. You will ...

  15. Estimation of bone mineral density by digital X-ray radiogrammetry: theoretical background and clinical testing

    DEFF Research Database (Denmark)

    Rosholm, A; Hyldstrup, L; Backsgaard, L;

    2002-01-01

    was observed to be 0.60% in a clinical study of 24 women and the in vitro variation over 12 different radiological clinics was found to be 1% of the young normal BMDDXR level. In a cohort of 416 women BMDDXR was found to be closely correlated with BMD at the distal forearm measured by dual-energy X...

  16. Thoracic spine x-ray

    Science.gov (United States)

    Vertebral radiography; X-ray - spine; Thoracic x-ray; Spine x-ray; Thoracic spine films; Back films ... care provider's office. You will lie on the x-ray table in different positions. If the x-ray ...

  17. X-ray (image)

    Science.gov (United States)

    X-rays are a form of ionizing radiation that can penetrate the body to form an image on ... will be shades of gray depending on density. X-rays can provide information about obstructions, tumors, and other ...

  18. Dental x-rays

    Science.gov (United States)

    X-ray - teeth; Radiograph - dental; Bitewings; Periapical film; Panoramic film ... dentist's office. There are many types of dental x-rays. Some are: Bitewing Periapical Palatal (also called occlusal) ...

  19. X-ray apparatus

    International Nuclear Information System (INIS)

    A diagnostic x-ray device, readily convertible between conventional radiographic and tomographic operating modes, is described. An improved drive system interconnects and drives the x-ray source and the imaging device through coordinated movements for tomography

  20. Dental x-rays

    Science.gov (United States)

    X-ray - teeth; Radiograph - dental; Bitewings; Periapical film; Panoramic film; Digital image ... dentist's office. There are many types of dental x-rays. Some of them are: Bitewing. Shows the crown ...

  1. X-Rays

    Science.gov (United States)

    X-rays are a type of radiation called electromagnetic waves. X-ray imaging creates pictures of the inside of your ... different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat and ...

  2. Chest X-Ray

    Medline Plus

    Full Text Available ... by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript Welcome to Radiology Info dot org! Hello, ... you about chest radiography also known as chest x-rays. Chest x-rays are the most commonly performed ...

  3. Correlation of Ordered Cervical Spine X-rays in Emergency Department with NEXUS and Canadian C-Spine Rules; a Clinical Audit

    Directory of Open Access Journals (Sweden)

    Hamid Kariman

    2015-10-01

    Full Text Available Introduction: Evaluation of cervical spine injuries makes up a major part of trauma patient assessments. Based on the existing sources, more than 98% of the cervical spine X-rays show no positive findings. Therefore, the present clinical audit aimed to evaluate the correlation of ordered cervical spine X-rays in multiple trauma patients with NEXUS and Canadian c-spine clinical decision rules. Methods: The present clinical audit, evaluated the correlation of cervical spine imaging orders in multiple trauma patients presented to the emergency department, with NEXUS and Canadian c-spine rules. Initially, in a pilot study, the mentioned correlation was evaluated, and afterwards the results of this phase was analyzed. Since the correlation was low, an educational training was planned for all the physicians in charge. Finally, the calculated correlations for before and after training were compared using SPSS version 21. Results: Before and after training, cervical spine X-ray was ordered for 98 (62.82% and 85 (54.48% patients, respectively. Accuracy of cervical spine X-ray orders, based on the standard clinical decision rules, increased from 100 (64.1% cases before training, to 143 (91.7% cases after training (p < 0.001. Area under the receiver operating characteristic (ROC curve regarding the correlation also raised from 52 (95% confidence interval (CI: 43 – 61 to 92 (95% CI: 87 – 97. Conclusion: Teaching NEXUS and Canadian c-spine clinical decision rules plays a significant role in improving the correlation of cervical spine X-ray orders in multiple trauma patients with the existing standards.

  4. Radiotherapy in the management of keloids. Clinical experience with electron beam irradiation and comparison with X-ray therapy

    Energy Technology Data Exchange (ETDEWEB)

    Maarouf, M. [Dept. of Radiotherapy, Univ. of Technology (RWTH), Aachen (Germany); Dept. of Stereotactic and Functional Neurosurgery, Univ. of Cologne (Germany); Schleicher, U.; Schmachtenberg, A.; Ammon, J. [Dept. of Radiotherapy, Univ. of Technology (RWTH), Aachen (Germany)

    2002-06-01

    Background: Aim of this study was to evaluate the advantages of electron beam irradiation compared to kilovoltage X-ray therapy in the treatment of keloids. Furthermore, the risk of developing malignancy following keloid radiotherapy was assessed. Patients and Methods: An automatic water phantom was used to evaluate the dose distribution in tissue. Furthermore, a series of measurements was done on the patients using thermoluminescence dosimeters (TLD) to estimate the doses absorbed by the organs at risk. We also report our clinical experience with electron beam radiation of 134 keloids following surgical excision. Results: Electron beam irradiation offers a high control rate (84%) with minimal side effects for keloids. Electron irradiation provides better dose distribution in tissue, and therefore less radiation burden to the organs at risk. After a mean follow-up period of 7.2 years, no severe side effects or malignancies were observed after keloid radiotherapy. Conclusions: Electron radiation therapy is superior to kilovoltage irradiation for treating keloids due to better dose distribution in tissue. In agreement with the literature, no cases of malignancy were observed after keloid irradiation. (orig.)

  5. Dual-energy X-ray performs as well as clinical computed tomography for the measurement of visceral fat.

    Science.gov (United States)

    Micklesfield, Lisa K; Goedecke, Julia H; Punyanitya, Mark; Wilson, Kevin E; Kelly, Thomas L

    2012-05-01

    Visceral adipose tissue (VAT) is associated with adverse health effects including cardiovascular disease and type 2 diabetes. We developed a dual-energy X-ray absorptiometry (DXA) measurement of visceral adipose tissue (DXA-VAT) as a low cost and low radiation alternative to computed tomography (CT). DXA-VAT was compared to VAT assessed using CT by an expert reader (E-VAT). In addition, the same CT slice was also read by a clinical radiographer (C-VAT) and a best-fit anthropomorphic and demographic VAT model (A-VAT) was developed. Whole body DXA, CT at L4-L5, and anthropometry were measured on 272 black and white South African women (age 29 ± 8 years, BMI 28 ± 7 kg/m(2), waist circumference (WC) 89 ± 16 cm). Approximately one-half of the dataset (n = 141) was randomly selected and used as a training set for the development of DXA-VAT and A-VAT, which were then used to estimate VAT on the remaining 131 women in a blinded fashion. DXA-VAT (r = 0.93, standard error of the estimate (SEE) = 16 cm(2)) and C-VAT (r = 0.93, SEE = 16 cm(2)) were strongly correlated to E-VAT. These correlations with E-VAT were significantly stronger (P < 0.001) than the correlations of individual anthropometry measurements and the A-VAT model (WC + age, r = 0.79, SEE = 27 cm(2)). The inclusion of anthropometric and demographic measurements did not substantially improve the correlation between DXA-VAT and E-VAT. DXA-VAT performed as well as a clinical read of VAT from a CT scan and better than anthropomorphic and demographic models. PMID:22240726

  6. X-Ray Polarimetry

    CERN Document Server

    Kaaret, Philip

    2014-01-01

    We review the basic principles of X-ray polarimetry and current detector technologies based on the photoelectric effect, Bragg reflection, and Compton scattering. Recent technological advances in high-spatial-resolution gas-filled X-ray detectors have enabled efficient polarimeters exploiting the photoelectric effect that hold great scientific promise for X-ray polarimetry in the 2-10 keV band. Advances in the fabrication of multilayer optics have made feasible the construction of broad-band soft X-ray polarimeters based on Bragg reflection. Developments in scintillator and solid-state hard X-ray detectors facilitate construction of both modular, large area Compton scattering polarimeters and compact devices suitable for use with focusing X-ray telescopes.

  7. X-Ray Polarimetry

    OpenAIRE

    Kaaret, Philip

    2014-01-01

    We review the basic principles of X-ray polarimetry and current detector technologies based on the photoelectric effect, Bragg reflection, and Compton scattering. Recent technological advances in high-spatial-resolution gas-filled X-ray detectors have enabled efficient polarimeters exploiting the photoelectric effect that hold great scientific promise for X-ray polarimetry in the 2-10 keV band. Advances in the fabrication of multilayer optics have made feasible the construction of broad-band ...

  8. Impact of miscentering on patient dose and image noise in x-ray CT imaging : Phantom and clinical studies

    NARCIS (Netherlands)

    Habibzadeh, M. A.; Ay, M. R.; Asl, A. R. Kamali; Ghadiri, H.; Zaidi, H.

    2012-01-01

    The operation of the bowtie filter in x-ray CT is correct if the object being scanned is properly centered in the scanner's field-of-view. Otherwise, the dose delivered to the patient and image noise will deviate from optimal setting. We investigate the effect of miscentering on image noise and surf

  9. Comparison of kVp and PPV measurements between a constant potential and a clinical X-ray system used for calibration in mammography

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Eduardo de L.; Vivolo, Vitor; Potiens, Maria da Penha A., E-mail: vivolo@ipen.b, E-mail: mppalbu@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The PPV is an electrical quantity that relates the peak voltage with the radiological image contrast, thus having a larger clinical application. By definition, in an X-ray system, the 'PPV is a quantity based on the concept that the radiation generated by a high voltage source with an arbitrary wave source produces the same radiographic contrast that the radiation generated by a high voltage source with an equivalent constant potential'. The Instruments Calibration Laboratory (LCI) of IPEN has the mammography qualities established in a constant potential system (industrial X-ray system), and also in a clinical system (mammograph). The objective of this study was to analyze the PPV behavior in these systems, and try to reach calibration conditions that are more similar to the work conditions in hospitals and clinics. For this, it was used an industrial X-ray (constant potential) and a mammography system (high frequency). The first system has a tungsten (W) target, and additional filtration of aluminum (Al) and molybdenum (Mo), and the second one has a Mo target and additional filtration of Mo and rhodium (Rh). A non-invasive measuring system from PTW model Diavolt was used to PPV determination. The voltages used were 25 kV, 28 kV, 30 kV and 35 kV (calibration qualities in mammography, according to the IEC 61267). The Diavolt was placed one meter from the focal spot in the industrial X-ray system, and 60 cm for the clinical system. (author)

  10. X-ray - skeleton

    Science.gov (United States)

    A skeletal x-ray is an imaging test used to look at the bones. It is used to detect fractures , tumors, or ... in the health care provider's office by an x-ray technologist. You will lie on a table or ...

  11. Extremity x-ray

    Science.gov (United States)

    An extremity x-ray is an image of the hands, wrist, feet, ankle, leg, thigh, forearm humerus or upper arm, hip, shoulder ... term "extremity" often refers to a human limb. X-rays are a form of radiation that passes through ...

  12. X-ray interferometers

    International Nuclear Information System (INIS)

    An improved type of amplitude-division x-ray interferometer is described. The wavelength at which the interferometer can operate is variable, allowing the instrument to be used to measure x-ray wavelength, and the angle of inclination is variable for sample investigation. (U.K.)

  13. X-ray crystallography

    Science.gov (United States)

    2001-01-01

    X-rays diffracted from a well-ordered protein crystal create sharp patterns of scattered light on film. A computer can use these patterns to generate a model of a protein molecule. To analyze the selected crystal, an X-ray crystallographer shines X-rays through the crystal. Unlike a single dental X-ray, which produces a shadow image of a tooth, these X-rays have to be taken many times from different angles to produce a pattern from the scattered light, a map of the intensity of the X-rays after they diffract through the crystal. The X-rays bounce off the electron clouds that form the outer structure of each atom. A flawed crystal will yield a blurry pattern; a well-ordered protein crystal yields a series of sharp diffraction patterns. From these patterns, researchers build an electron density map. With powerful computers and a lot of calculations, scientists can use the electron density patterns to determine the structure of the protein and make a computer-generated model of the structure. The models let researchers improve their understanding of how the protein functions. They also allow scientists to look for receptor sites and active areas that control a protein's function and role in the progress of diseases. From there, pharmaceutical researchers can design molecules that fit the active site, much like a key and lock, so that the protein is locked without affecting the rest of the body. This is called structure-based drug design.

  14. Bone X-Ray (Radiography)

    Medline Plus

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

  15. Bone X-Ray (Radiography)

    Medline Plus

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

  16. Lumbosacral spine x-ray

    Science.gov (United States)

    X-ray - lumbosacral spine; X-ray - lower spine ... The test is done in a hospital x-ray department or your health care provider's office by an x-ray technician. You will be asked to lie on the x-ray table ...

  17. Bone X-Ray (Radiography)

    Medline Plus

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

  18. Abdomen X-Ray (Radiography)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Abdomen Abdominal x-ray uses a very ... of an abdominal x-ray? What is abdominal x-ray? An x-ray (radiograph) is a noninvasive medical ...

  19. X-ray lasers

    CERN Document Server

    Elton, Raymond C

    2012-01-01

    The first in its field, this book is both an introduction to x-ray lasers and a how-to guide for specialists. It provides new entrants and others interested in the field with a comprehensive overview and describes useful examples of analysis and experiments as background and guidance for researchers undertaking new laser designs. In one succinct volume, X-Ray Lasers collects the knowledge and experience gained in two decades of x-ray laser development and conveys the exciting challenges and possibilities still to come._Add on for longer version of blurb_M>The reader is first introduced

  20. Comparison of Clinical and Laboratory Responses in Sheep and Dogs following Whole-Body Exposures to 250-Kvp X-Rays and Fission-Spectrum Neutrons

    International Nuclear Information System (INIS)

    Fifteen sheep and eight dogs were exposed to 400 rad (air dose) of pulsed fission-spectrum neutrons, and an equal number of sheep and 14 dogs to 400 r (midline air dose) 250 kVp X-rays. Seven additional sheep and four dogs served as un-irradiated controls. Control data were obtained for two weeks preceding the exposures and at frequent and regular intervals after the injury. In sheep, the most consistent clinical change was complete loss of wool by the 51st day post-exposure. The underlying skin was pink in colour closely resembling that of a mild blush sometimes noted in humans. Dogs did not demonstrate loss of hair. Formed blood elements, neutrophils, lymphocytes, and thrombocytes fell rapidly after the radiation in both species. At about post-exposure day 24 recovery in white cell numbers was noted only in the neutron groups. Thrombocyte levels decreased to safe level in both species but somewhat earlier in the dog. Recovery appeared during the third post-exposure week in both species ex posed to neutrons, but not in those given X-rays. Red blood-cell haematocrits showed significant drops in both groups of dogs by the ninth day, but neither group of sheep exhibited significant decrease in haematocrit values. Plasma Fe59 clearance rates were determined in the experimental subjects as a parameter of measurement of haematopoietic function. Prognostic implications of alteration in this parameter of haemapoiesis are discussed. The most significant gross-pathologic changes were confined to the lungs wherein extensive perivascular haemorrhage around the arteries was noted. On microscopic study the area of haemorrhage was observed to be within the advential-connective tissue and periarterial vessels. Thirty-day mortality for dogs was 50% following neutron exposures and 93% after the X-ray insult. In sheep neutrons produced 22% mortality and X-rays 80%. (author)

  1. X线诊断早期食道癌患者的临床研究%Clinical Study of X-ray Diagnosis of Early Esophageal Cancer

    Institute of Scientific and Technical Information of China (English)

    杨庆艳

    2016-01-01

    Objective To explore the clinical study of X-ray diagnosis of early esophageal cancer patients. Methods Selected 50 cases of esophageal cancer patients in our hospital, admitted time were concentrated from March 2014 to April 2015, which were divided the dynamic randomization of patients into observation group (25 cases) and control group (25 cases), the control group was treated with double contrast radiography, the observation group using X-ray diagnosis. Results By the X-ray diagnosis of the observation group, diagnostic accuracy was 96.00%, compared with double imaging diagnosis of the control group, the diagnostic accuracy was 56.00%, the observation group was significantly better than the control group (P <0.05). Conclusion X-ray diagnosis of early esophageal cancer patients with significant effect.%目的:探索 X 线诊断早期食道癌患者的临床研究。方法选取我院50例食道癌患者,收治时间均集中在2014年3月~2015年4月,将患者动态随机化分为观察组(25例)和对照组(25例),对照组采用双对比造影诊断,观察组采用 X 线诊断。结果经 X 线诊断的观察组,诊断准确率为96.00%,经双对比造影诊断的对照组,诊断准确率为56.00%,观察组优于对照组(P <0.05)。结论 X 线诊断早期食道癌患者效果显著。

  2. Applying psychological theories to evidence-based clinical practice: identifying factors predictive of lumbar spine x-ray for low back pain in UK primary care practice

    Directory of Open Access Journals (Sweden)

    Thomas Ruth

    2011-05-01

    Full Text Available Abstract Background Psychological models predict behaviour in a wide range of settings. The aim of this study was to explore the usefulness of a range of psychological models to predict the health professional behaviour 'referral for lumbar spine x-ray in patients presenting with low back pain' by UK primary care physicians. Methods Psychological measures were collected by postal questionnaire survey from a random sample of primary care physicians in Scotland and north England. The outcome measures were clinical behaviour (referral rates for lumbar spine x-rays, behavioural simulation (lumbar spine x-ray referral decisions based upon scenarios, and behavioural intention (general intention to refer for lumbar spine x-rays in patients with low back pain. Explanatory variables were the constructs within the Theory of Planned Behaviour (TPB, Social Cognitive Theory (SCT, Common Sense Self-Regulation Model (CS-SRM, Operant Learning Theory (OLT, Implementation Intention (II, Weinstein's Stage Model termed the Precaution Adoption Process (PAP, and knowledge. For each of the outcome measures, a generalised linear model was used to examine the predictive value of each theory individually. Linear regression was used for the intention and simulation outcomes, and negative binomial regression was used for the behaviour outcome. Following this 'theory level' analysis, a 'cross-theoretical construct' analysis was conducted to investigate the combined predictive value of all individual constructs across theories. Results Constructs from TPB, SCT, CS-SRM, and OLT predicted behaviour; however, the theoretical models did not fit the data well. When predicting behavioural simulation, the proportion of variance explained by individual theories was TPB 11.6%, SCT 12.1%, OLT 8.1%, and II 1.5% of the variance, and in the cross-theory analysis constructs from TPB, CS-SRM and II explained 16.5% of the variance in simulated behaviours. When predicting intention, the

  3. X-Ray Diffraction.

    Science.gov (United States)

    Smith, D. K.; Smith, K. L.

    1980-01-01

    Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

  4. Medical X-Rays

    Science.gov (United States)

    ... The Conference of Radiation Control Program Directors (CRCPD) publishes Suggested State Regulations for the Control of Radiation , ... eSubmitter Guidance for Industry and Food and Drug Administration Staff - Assembler's Guide to Diagnostic X-Ray Equipment ...

  5. Chest X-Ray

    Medline Plus

    Full Text Available ... However, it’s important to consider the likelihood of benefit to your health. While a chest x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs any risk. ...

  6. Chest X-Ray

    Medline Plus

    Full Text Available ... chest x-ray is used to evaluate the lungs, heart and chest wall and may be used ... diagnose and monitor treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  8. 新生儿气胸的临床与X线分析%Clinical and X-ray Analysis of Pneumothorax in Newborn

    Institute of Scientific and Technical Information of China (English)

    裘华兴; 夏瑞明

    2011-01-01

    Objective To analyse the clinical and X-ray characteristics of pneumothorax in newborn, so that to improve the knowledge of pneumothorax in newborn. Methods 52 cases of pneumothorax in newborn underwent chest anterioposterior radiography at supine position and horizontal supine lateral position in some cases. All cases followed-up with X-ray. Results According to X-ray manifestations of pneumothorax, pneumothorax in newborn included four types : adult type in 5 cases , medial margin type in 29 cases ,superior diaphragm type in 12 cases and anterior chest wall type in 6 cases,which appeared as lateral pneumothorax,medial mediastinum side pneumothorax, diaphragmatic surface nearby pneumothorax and prethoracic pneumothorax on X-ray images , respectively. 13 infants simultaneously suffered from pneumomediastinum. Conclusion X-ray manifestations of pneumothorax in newborn are of certain characteristics.%目的 分析新生儿气胸的临床与X线特点,提高对新生儿气胸的认识与X线诊断水平.方法 52例新生儿气胸,摄取仰卧前后位胸片,部分患者加摄仰卧水平侧位片,所有病例均经X线片随访复查.结果 根据气胸X线表现,新生儿气胸可分为4种类型:成人型,内侧缘型,膈上型和前胸壁型.X线分别表现为外侧气胸、内侧纵隔旁气胸、膈面附近气胸及胸前部气胸.52例气胸患儿中,成人型5例,内侧缘型29例,膈上型12例,前胸壁型6例.另外,同时伴有纵隔积气13例.结论 新生儿气胸有一定X线特征.

  9. Realization of fluence field modulated CT on a clinical TomoTherapy megavoltage CT system

    International Nuclear Information System (INIS)

    The multi-leaf collimator (MLC) assembly present on TomoTherapy (Accuray, Madison WI) radiation therapy (RT) and mega voltage CT machines is well suited to perform fluence field modulated CT (FFMCT). In addition, there is a demand in the RT environment for FFMCT imaging techniques, specifically volume of interest (VOI) imaging.A clinical TomoTherapy machine was programmed to perform VOI. Four different size ROIs were placed at varying distances from isocenter. Projections intersecting the VOI received ‘full dose’ while those not intersecting the VOI received 30% of the dose (i.e. the incident fluence for non VOI projections was 30% of the incident fluence for projections intersecting the VOI). Additional scans without fluence field modulation were acquired at ‘full’ and 30% dose. The noise (pixel standard deviation) and mean CT number were measured inside the VOI region and compared between the three scans. Dose maps were generated using a dedicated TomoTherapy treatment planning dose calculator.The VOI-FFMCT technique produced an image noise 1.05, 1.00, 1.03, and 1.05 times higher than the ‘full dose’ scan for ROI sizes of 10 cm, 13 cm, 10 cm, and 6 cm respectively within the VOI region. The VOI-FFMCT technique required a total imaging dose equal to 0.61, 0.69, 0.60, and 0.50 times the ‘full dose’ acquisition dose for ROI sizes of 10 cm, 13 cm, 10 cm, and 6 cm respectively within the VOI region.Noise levels can be almost unchanged within clinically relevant VOIs sizes for RT applications while the integral imaging dose to the patient can be decreased, and/or the image quality in RT can be dramatically increased with no change in dose relative to non-FFMCT RT imaging. The ability to shift dose away from regions unimportant for clinical evaluation in order to improve image quality or reduce imaging dose has been demonstrated. This paper demonstrates that FFMCT can be performed using the MLC on a clinical TomoTherapy machine for the

  10. Alignments? X-ray Diversions, Haptics, Credibility--With a 'Bone-Setting' Clinic in Hyderabad City.

    Science.gov (United States)

    Attewell, Guy

    2016-01-01

    In this article, I engage with the diversions of technologies conventionally used for diagnostic scanning among practitioners who perform fracture-reduction and related manual interventions around bodily pain, ostensibly outside the mainstream orthopedic sector, in the city of Hyderabad, south central India. I attend to the performative dimensions of a technology-practice assemblage, and show how enactments of fracture reduction as viable and credible, targeted at establishment orthopedic surgeons, have been enabled through a distributive agency, afforded by scanning technologies. The use of X-rays and other medical scanning technologies by nonbiomedical practitioners have not displaced haptic and other technics of embodied knowledge, but they have been mobilized in order to create wider recognition of the practitioners' skills. This is a process in which a new configuration of medical practice is constituted.

  11. X-ray Pulsars

    CERN Document Server

    Walter, Roland

    2016-01-01

    X-ray pulsars shine thanks to the conversion of the gravitational energy of accreted material to X-ray radiation. The accretion rate is modulated by geometrical and hydrodynamical effects in the stellar wind of the pulsar companions and/or by instabilities in accretion discs. Wind driven flows are highly unstable close to neutron stars and responsible for X-ray variability by factors $10^3$ on time scale of hours. Disk driven flows feature slower state transitions and quasi periodic oscillations related to orbital motion and precession or resonance. On shorter time scales, and closer to the surface of the neutron star, X-ray variability is dominated by the interactions of the accreting flow with the spinning magnetosphere. When the pulsar magnetic field is large, the flow is confined in a relatively narrow accretion column, whose geometrical properties drive the observed X-ray emission. In low magnetized systems, an increasing accretion rate allows the ignition of powerful explosive thermonuclear burning at t...

  12. X-ray astronomy

    International Nuclear Information System (INIS)

    This book contains the lectures, and the most important seminars held at the NATO meeting on X-Ray astronomy in Erice, July 1979. The meeting was an opportune forum to discuss the results of the first 8-months of operation of the X-ray satellite, HEAO-2 (Einstein Observatory) which was launched at the end of 1978. Besides surveying these results, the meeting covered extragalactic astronomy, including the relevant observations obtained in other portions of the electromagnetic spectrum (ultra-violet, optical, infrared and radio). The discussion on galactic X-ray sources essentially covered classical binaries, globular clusters and bursters and its significance to extragalactic sources and to high energy astrophysics was borne in mind. (orig.)

  13. A statistical survey of x-ray CT cases at the Clinic of Oral and Maxillofacial Radiology, Chiba Hospital, Tokyo Dental College

    International Nuclear Information System (INIS)

    Statistical study was performed of x-ray CT cases at the Clinic of Oral and Maxillofacial Radiology, Chiba Hospital, Tokyo Dental College since a Toshiba CT Scanner TCT-700S was settled in 1988, until December 1994. Total number of cases photographed was 2645 cases, Male; 1447 (54.7%), Female; 1198 cases (45.3%). Total number of cases yearly photographed have increased every year. 95.43% of the cases were the diseases of oral surgery regions. X-ray CT has been used to malignant tumors (730 cases; 29.7%), cyst (435 cases; 17.7%), inflammation (362 cases; 14.7%), benign tumors (261 cases; 10.6%), injury (171 cases; 7.0%), salivary gland diseases (126 cases; 5.1%) and others. The number of tumors and cyst have been increasing every year. Average number of slices in every diseases were counted. Malignant tumor, injury, temporomandibular joint diseases, and congenital anomalies and malformations were counted many slices. Percentages of number of enhanced CT cases have been increased every year. Recently, number of enhanced CT cases have more number than non-enhanced CT cases. This attitude is correlated with the number of malignant tumors which have been increasing every year. Total number of cases of three dimensional imaging CT (3D-CT) was 316 cases. 3D-CT has been used to injury (146 cases; 46.2%), temporomandibular joint diseases (52 cases; 16.4%), congenital anomalies and malformations (49 cases; 15.5%), tumors (21 cases; 6.7%), cyst (13 cases; 4.1%) and others. The need of x-ray CT in our field and the tendency of dental treatment at Chiba Hospital might be changed in the future. In order to this situation, this type of statistical study will be performed again. (author)

  14. CRL X-RAY TUBE

    OpenAIRE

    Kolchevsky, N. N.; Petrov, P. V.

    2015-01-01

    A novel types of X-ray tubes with refractive lenses are proposed. CRL-R X-ray tube consists of Compound Refractive Lens- CRL and Reflection X-ray tube. CRL acts as X-ray window. CRL-T X-ray consists of CRL and Transmission X-ray tube. CRL acts as target for electron beam. CRL refractive lens acts as filter, collimator, waveguide and focusing lens. Properties and construction of the CRL X-ray tube are discussed.

  15. The dosimetry of eye shields for kilovoltage X-ray beams

    International Nuclear Information System (INIS)

    The objective of this work was to evaluate the dosimetry of tungsten eye shields for use with kilovoltage X-ray beam treatments. The eye shields, originally designed for megavoltage electron beams, were made of 2 mm tungsten thickness and inside diameters of 11.6 and 15.0 mm with optional aluminium caps of 0.5 and 1 mm thickness. The relative dosimetry of the eye shields were examined by measurement of transmission doses with full scatter conditions, central axis depth doses and beam profiles underneath the eye shield. The X-ray beams used in this study ranged in energy from 50 to 280 kVp. Transmission measurements were performed using an Advanced Markus ionisation chamber located at the surface of an RMI457 Solid Water phantom with a 3 cm diameter applicator flush against the phantom surface. Depth doses and profiles measurements were performed in a PTW MP3 scanning water tank with a PTW diamond detector. Results for transmission doses for the medium size eye shield increased from 1 to 22 % for 50–280 kVp while for the smaller eye shield the percentage dose increased from 3.5 to 30 % for the same energy range. There were minimal differences between using the 0.5 and 1 mm aluminium caps. Central axis depth doses measured with and without the eye shields demonstrated the 125 and 180 kVp beams had higher peak doses behind the eye shields. These results show that these tungsten eye shields are suitable for use with kilovoltage X-ray beams. However, the clinical impact needs to be considered for the higher X-ray beam energies.

  16. Chest X-Ray

    Medline Plus

    Full Text Available ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript ... time! Spotlight Recently posted: Pediatric MRI Intravascular Ultrasound Video: Chest CT Video:Thyroid Ultrasound Video: Head CT ...

  17. Chest X-Ray

    Medline Plus

    Full Text Available ... Pediatric Ultrasound Video: Angioplasty & vascular stenting Video: Arthrography Radiology and You About this Site RadiologyInfo.org is ... radiologist explains chest x-ray. Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey ...

  18. Chest X-Ray

    Medline Plus

    Full Text Available ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript ... Recently posted: Focused Ultrasound for Uterine Fibroids Dementia Video: General Ultrasound Video: Pediatric Nuclear Medicine Radiology and ...

  19. Medical x-ray

    International Nuclear Information System (INIS)

    This book describes the fundamental subject about medical radiography. It is a multidisciplinary field that requires cross professional input from scientists, engineers and medical doctors. However, it is presented in simple language to suit different levels of readers from x-ray operators and radiographers to physists, general practitioners and radiology specialists.The book is written in accordance to the requirements of the standard syllabus approved by the Ministry of Health Malaysia for the training of medical x-ray operator and general practitioners. In general, the content is not only designed to provide relevant and essential subject for related professionals in medical radiological services such as x-ray operator, radiographer and radiologists, but also to address those in associated radiological services including nurses, medical technologists and physicists.The book is organized and arranged sequentially into 3 parts for easy reference: Radiation safety; X-ray equipment and associated facilities; Radiography practices. With proper grasping of all these parts, the radiological services could be provided with confident and the highest professional standard. Thus, medical imaging with highest quality that can provide useful diagnostic information at minimum doses and at cost effective could be assured

  20. Dental biothermophotonics: How photothermal methods are winning the race with X-rays for dental caries diagnostic needs of clinical dentistry

    Science.gov (United States)

    Mandelis, A.; Jeon, R.; Matvienko, A.; Abrams, S. H.; Amaechi, B. T.

    2008-01-01

    Recent trends in biothermophotonics of teeth are presented. The presentation is centered on the development of clinical-level frequency-domain photothermal radiometry and modulated luminescence to address issues associated with the early diagnosis of demineralization caries in human teeth. Biothermophotonic principles and applications to the detection of the carious state in human teeth as embodied by laser photothermal radiometry are presented and further supported by modulated luminescence. The emphasis is on recent developments with regard to abilities of these techniques to diagnose interproximal lesions between teeth, etching with phosphoric acid and with an artificial demineralization gel in order to simulate early demineralization, as well as demineralization and remineralization of dental crown enamel and root dentin. These are lesions which normally go undetected by X-ray radiographs. Comparisons with X rays, Micro-Computed Tomography (μ-CT) and Transverse Micro-Radiography (TMR) are discussed. A theoretical model involving coupled diffuse photon density and thermal-wave fields is developed and applied to frequency scans from demineralized artificial lesions to produce quantitative values for optical and thermophysical parameters of teeth as well as the thickness of the induced lesion.

  1. Pyroelectric x-ray detectors and x-ray pyrometers

    International Nuclear Information System (INIS)

    This paper discusses pyroelectric detectors which are very promising x-ray detectors for intense pulsed x-ray/γ-ray measurements and can be used as x-ray pyrometers. They are fast, passive, and inherently flat in spectral response for low energy x-rays. The authors report tests of LiTaO3, Sr.5Ba.5Nb2O6 and LiNbO3 detectors at Nova laser with 1 ns low energy x-rays and at Zapp Z-pinch machine with 100 ns x-rays. The temporal and spectral responses are discussed

  2. Pyroelectric x-ray detectors and x-ray pyrometers

    International Nuclear Information System (INIS)

    Pyroelectric detectors are very promising x-ray detectors for intense pulsed x-ray/γ-ray measurements and can be used as x-ray pyrometers. They are fast, passive, and inherently flat in spectral response for low-energy x rays. We report our tests of LiTaO3 detectors at Nova laser with 1-ns low-energy x rays and at Zapp Z-pinch machine with 100-ns x rays. The temporal and spectral responses are discussed

  3. Comparative X-ray investigation of lateral and anterior-posterior ankle-joint images - comparison with pathological and anatomical findings concerning lateral ankle-joint lesions and their clinical importance, studied in a special type of holding device

    International Nuclear Information System (INIS)

    The study reports on a possibility to interpret the relation of the different bone structures of the upper ankle-joint to one another in the X-ray picture without using contrast media. Modern funtional diagnostic methods increasingly make use of X-ray pictures taken in fixed position. It seems useful to standardize such X-ray images of the ankle-joint in order to make them reproducible. The author developed a device that would suit these purposes. A diagnosis required the reproduction of the accidental mechanism. The clinical symptoms do not permit to clearly state the extent of the lesion of the ligaments. The results of the post-operative follow-up examinations confirm the urgent necessity of the standardized diagnostic method presented and the success of the therapy applied. The presented X-ray method permits safe diagnosis of ruptures of the ligaments. Location of a certain rupture is not possible with the fixed-position X-ray screening. For a clear assessment of lesions of the ligaments at the lateral ankle-joint, X-ray pictures must be taken both in the anterior-posterior path of rays and in the lateral one. A normal result in the lateral path of rays does not exclude a pathologic result in the anterior-posterior path of rays, and vice versa. (orig./MG)

  4. X-ray diffraction

    International Nuclear Information System (INIS)

    We have been interested in structural elucidation by x-ray diffraction of compounds of biological interest. Understanding exactly how atoms are arranged in three-dimensional arrays as molecules can help explain the relationship between structure and functions. The species investigated may vary in size and shape; our recent studies included such diverse substances as antischistosomal drugs, a complex of cadmium with nucleic acid base, nitrate salts of adenine, and proteins

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... wrist, arm, elbow, shoulder, spine, pelvis, hip, thigh, knee, leg (shin), ankle or foot. top of page ... the patient standing upright, as in cases of knee x-rays. A portable x-ray machine is ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... images for evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement and fracture reductions. look for injury, ... and Media Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to X-ray ( ...

  8. 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? ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and ...

  9. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Intra-oral dental X-ray apparatus for panoramic radiography is described in detail. It comprises a tubular target carrier supporting at its distal end a target with an inclined forward face. Image definition is improved by positioning in the path of the X-rays a window of X-ray transmitting ceramic material, e.g. 90% oxide of Be, or Al, 7% Si02. The target carrier forms a probe which can be positioned in the patient's mouth. X-rays are directed forwardly and laterally of the target to an X-ray film positioned externally. The probe is provided with a detachable sleeve having V-form arms of X-ray opaque material which serve to depress the tongue out of the radiation path and also shield the roof of the mouth and other regions of the head from the X-ray pattern. A cylindrical lead shield defines the X-ray beam angle. (author)

  10. 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? ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... As a result, bones appear white on the x-ray, soft tissue shows up in shades of gray and air appears black. Until recently, x-ray images were maintained on large film sheets (much ...

  12. Panoramic Dental X-Ray

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a ... a large photographic negative). Today, most images are digital files that are stored electronically. These stored images ...

  13. SU-E-J-37: Combining Proton Radiography and X-Ray CT Information to Better Estimate Relative Proton Stopping Power in a Clinical Environment

    International Nuclear Information System (INIS)

    Purpose: In standard proton therapy clinical practice, proton stopping power uncertainties are in the order of 3.5%, which affects the ability of placing the proton Bragg peak at the edge of the tumor. The innovating idea of this project is to approach the uncertainty problem in RSP by using combined information from X-ray CT and proton radiography along a few beam angles. In addition, this project aims to quantify the systematic error introduced by the theoretical models (Janni, ICRU49, Bischel) for proton stopping power in media. Methods: A 3D phantom of 36 cm3 composed of 9 materials randomly placed is created. Measured RSP values are obtained using a Gammex phantom with a proton beam. Theoretical RSP values are calculated with Beth-Block equation in combination with three databases (Janni, ICRU49 and Bischel). Clinical RSP errors are simulated by introducing a systematic (1.5%, 2.5%, 3.5%) and a random error (+/−0.5%) to the theoretical RSP. A ray-tracing algorithm uses each of these RSP tables to calculate energy loss for proton crossing the phantom through various directions. For each direction, gradient descent (GD) method is done on the clinical RSP table to minimize the residual energy difference between the simulation with clinical RSP and with theoretical RSP. The possibility of a systematic material dependent error is investigated by comparing measured RSP to theoretical RSP as calculated from the three models. Results: Using 10,000 iterations on GD algorithm, RSP differences between theoretical values and clinical RSP have converged (<1%) for each error introduced. Results produced with ICRU49 have the smallest average difference (0.021%) to the measured RSP. Janni (1.168%) and Bischel (−0.372%) database shows larger systematic errors. Conclusion: Based on these results, ray-tracing optimisation using information from proton radiography and X-ray CT demonstrates a potential to improve the proton range accuracy in a clinical environment

  14. X-ray Crystallography Facility

    Science.gov (United States)

    2000-01-01

    Edward Snell, a National Research Council research fellow at NASA's Marshall Space Flight Center (MSFC), prepares a protein crystal for analysis by x-ray crystallography as part of NASA's structural biology program. The small, individual crystals are bombarded with x-rays to produce diffraction patterns, a map of the intensity of the x-rays as they reflect through the crystal.

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... x-rays. top of page What does the equipment look like? The equipment typically used for bone x-rays consists of ... and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely available in emergency ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... The x-ray tube is connected to a flexible arm that is extended over the patient while an x-ray film holder or image recording plate is placed beneath the patient. top of page How does the procedure work? X-rays are a form of radiation like ...

  17. Tunable X-ray source

    Science.gov (United States)

    Boyce, James R.

    2011-02-08

    A method for the production of X-ray bunches tunable in both time and energy level by generating multiple photon, X-ray, beams through the use of Thomson scattering. The method of the present invention simultaneously produces two X-ray pulses that are tunable in energy and/or time.

  18. X-ray selected BALQSOs

    CERN Document Server

    Page, M J; Ceballos, M; Corral, A; Ebrero, J; Esquej, P; Krumpe, M; Mateos, S; Rosen, S; Schwope, A; Streblyanska, A; Symeonidis, M; Tedds, J A; Watson, M G

    2016-01-01

    We study a sample of six X-ray selected broad absorption line (BAL) quasi-stellar objects (QSOs) from the XMM-Newton Wide Angle Survey. All six objects are classified as BALQSOs using the classic balnicity index, and together they form the largest sample of X-ray selected BALQSOs. We find evidence for absorption in the X-ray spectra of all six objects. An ionized absorption model applied to an X-ray spectral shape that would be typical for non-BAL QSOs (a power law with energy index alpha=0.98) provides acceptable fits to the X-ray spectra of all six objects. The optical to X-ray spectral indices, alpha_OX, of the X-ray selected BALQSOs, have a mean value of 1.69 +- 0.05, which is similar to that found for X-ray selected and optically selected non-BAL QSOs of similar ultraviolet luminosity. In contrast, optically-selected BALQSOs typically have much larger alpha_OX and so are characterised as being X-ray weak. The results imply that X-ray selection yields intrinsically X-ray bright BALQSOs, but their X-ray sp...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... lies. A drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... that is extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  20. X-Ray Exam: Ankle

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Ankle KidsHealth > For Parents > X-Ray Exam: Ankle Print A A A Text Size ... español Radiografía: tobillo What It Is An ankle X-ray is a safe and painless test that uses ...

  1. X-Ray Exam: Finger

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Finger KidsHealth > For Parents > X-Ray Exam: Finger Print A A A Text Size ... español Radiografía: dedo What It Is A finger X-ray is a safe and painless test that uses ...

  2. X-Ray Exam: Wrist

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Wrist KidsHealth > For Parents > X-Ray Exam: Wrist Print A A A Text Size ... español Radiografía: muñeca What It Is A wrist X-ray is a safe and painless test that uses ...

  3. X-Ray Exam: Hip

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Hip KidsHealth > For Parents > X-Ray Exam: Hip Print A A A Text Size ... español Radiografía: cadera What It Is A hip X-ray is a safe and painless test that uses ...

  4. X-Ray Exam: Forearm

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Forearm KidsHealth > For Parents > X-Ray Exam: Forearm Print A A A Text Size ... español Radiografía: brazo What It Is A forearm X-ray is a safe and painless test that uses ...

  5. X-Ray Exam: Pelvis

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Pelvis KidsHealth > For Parents > X-Ray Exam: Pelvis Print A A A Text Size ... español Radiografía: pelvis What It Is A pelvis X-ray is a safe and painless test that uses ...

  6. X-Ray Exam: Foot

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Foot KidsHealth > For Parents > X-Ray Exam: Foot Print A A A Text Size ... español Radiografía: pie What It Is A foot X-ray is a safe and painless test that uses ...

  7. Phase II clinical study of boron neutron capture therapy combined with X-ray radiotherapy/temozolomide in patients with newly diagnosed glioblastoma multiforme-Study design and current status report

    Energy Technology Data Exchange (ETDEWEB)

    Kawabata, Shinji, E-mail: neu046@poh.osaka-med.ac.jp [Department of Neurosurgery, Osaka Medical College, 2-7 Daigaku-Machi, Takatsuki, Osaka 569-8686 (Japan); Miyatake, Shin-Ichi; Hiramatsu, Ryo; Hirota, Yuki; Miyata, Shiro; Takekita, Yoko; Kuroiwa, Toshihiko [Department of Neurosurgery, Osaka Medical College, 2-7 Daigaku-Machi, Takatsuki, Osaka 569-8686 (Japan); Kirihata, Mitsunori [Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8931 (Japan); Sakurai, Yoshinori; Maruhashi, Akira; Ono, Koji [Kyoto University Research Reactor Institute, 2 Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan)

    2011-12-15

    Recently, we reported our clinical experiences of boron neutron capture therapy (BNCT) for the newly diagnosed glioblastoma. The major differences of our protocol from the other past studies were simultaneous use of both sodium borocapate and boronophenylalanine, and combination with fractionated X-ray irradiation. These results showed the efficacy of combination therapy with external beam X-ray irradiation and BNCT. For our future study, we planned the multi-centric phase II clinical study for newly diagnosed glioblastoma patients in Japan (OSAKA-TRIBRAIN0902, NCT00974987).

  8. Clinical aspects of intraoperative radiotherapy in early breast cancer: short-term complications after IORT in women treated with low energy x-rays

    International Nuclear Information System (INIS)

    To assess postoperative complications, clinical outcome and histological findings in patients undergoing intraoperative radiotherapy with low energy x-rays for early breast cancer. We retrospectively analysed data of 208 women who underwent intraoperative irradiation during breast conserving surgery (BCS) between 2002 and 2007. Demographic, clinical and surgical parameters as well as short-term complications within the first postoperative week and histological findings were evaluated. Toxicities were assessed using the CTC/EORTC Score. Postoperative complications were rare and the immediate toxicity low, without any grade 3/4 acute toxicity. The most frequent postoperative side effects were suggillation (24%) and palpable seroma (17.3%). In 78.6% of the axillary seroma and in 25% of the breast seroma a needle aspiration was inevitable. Erythema grade I-II of the breast was found in 27 women (13%); whereas in 7 patients (3.4%), mastitis was confirmed. In 57.7% of the cases, the pathological assessment revealed ductal invasive breast cancer and tumour size ranged between 0.1 and 4.5 cm (mean = 1.6 cm). IORT using Intrabeam® during BCS is safe, although it is associated with postoperative adverse events such as seroma. These should be mentioned and explained to women in detail during the preoperative discussion. This explicitly clinical description is useful for daily clinical practice; especially for giving a detailed analysis of the postoperative side effects during preoperative counselling

  9. X-ray today

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, U. [Philips Medical Systems, Hamburg (Germany)

    2001-09-01

    The interest attracted by the new imaging modalities tends to overshadow the continuing importance of projection radiography and fluoroscopy. Nevertheless, projection techniques still represent by far the greatest proportion of diagnostic imaging examinations, and play an essential role in the growing number of advanced interventional procedures. This article describes some of the latest developments in X-ray imaging technology, using two products from the Philips range as examples: the Integris Allura cardiovascular system with 3D image reconstruction, and the BV Pulsera: a high-end, multi-functional mobile C-arm system with cardiac capabilities. (orig.)

  10. Digital x-ray analysis for monitoring fracture healing

    OpenAIRE

    Dawson, Sarah P.

    2009-01-01

    X-ray based evaluation of different stages of fracture healing is a well established clinical standard. However, several studies have shown plain radiography alone to be an unreliable method to assess healing. The advent of digital X-ray systems provides the potential to perform quantitative analysis on X-ray images without disrupting normal clinical practice. Two aspects were explored in this study. The first was the measurement of mechanical fracture stiffness under four point b...

  11. An evaluation of epoxy resin phantom materials for megavoltage photon dosimetry

    Science.gov (United States)

    Allahverdi, M.; Nisbet, A.; Thwaites, D. I.

    1999-05-01

    Epoxy resin phantom materials have been available for some time and are widely used for dosimetry purposes, not least in audit phantoms. Information on their behaviour is partly available in the literature, but there are different mixes and formulations often given similar names and it may not be appropriate to transfer information from one material to another. Five commercially available water-substitute materials have been evaluated for use in megavoltage photon beams: WT1, WTe, RMI 451, RMI 457 and `plastic water'. Four independent experiments were carried out to compare these materials with water in megavoltage photon beams ranging in energy from cobalt-60 to nominal 16 MV x-rays, and some general conclusions are drawn from the results as to their use. All are suitable for relative dosimetry in megavoltage photon beams. However, differences of up to 1% are observed for absolute measurements. The newer formulations, developed for electron beam use, are also closer to water for megavoltage photon beams.

  12. 床边移动X线机临床应用价值对比分析%Value Analysis for Clinical Application of Bedside Mobile X-ray Machine

    Institute of Scientific and Technical Information of China (English)

    何凤丽; 牛克伟; 巩守科

    2013-01-01

      目的:探讨床边移动X线机临床应用价值。方法:收集300张床边X光照片进行分析。结果:床边移动X线机300张照片152张甲级片,140张乙级片,8张丙级片。结论:床边移动X线机各有特点,移动DR摄影效果最佳。%Objective: To investigate the clinical application value of bedside mobile X-ray machine. Methods: Col ect 300 bedside X-ray photos analysis. Results:152 Class A tablets, 140 Class B tablets, 8 Class C tablets. Conclusion:Bedside mobile X-ray machine has different features, mobile DR photographic effect best.

  13. Construction of x-ray dark-field imaging with a view size of 80 mm square and first visualization of human articular cartilage of femoral head under a nearly clinical condition

    International Nuclear Information System (INIS)

    Field size of 80 mm x 80 mm for X-ray dark-field (DFI) imaging at 35 keV using a 2.16-mm-thick 440 Laue diffraction analyzer has been achieved. Under this condition, only refracted X-rays from sample can transmit through this filter to form DFI while the beam that has not changed its direction is repelled to the diffraction direction. Its spatial resolution is 10 microns or better. An excised human femoral head in a water-filled vinyl bag simulating a clinical condition shows a high-contrast and high-spatial-resolution articular cartilage that has not been visualized by X-ray technique. (author)

  14. SU-E-I-51: Quantitative Assessment of X-Ray Imaging Detector Performance in a Clinical Setting - a Simple Approach Using a Commercial Instrument

    Energy Technology Data Exchange (ETDEWEB)

    Sjoeberg, J; Bujila, R; Omar, A; Nowik, P; Mobini-Kesheh, S; Lindstroem, J [Karolinska University Hospital, Solna (Sweden)

    2015-06-15

    Purpose: To measure and compare the performance of X-ray imaging detectors in a clinical setting using a dedicated instrument for the quantitative determination of detector performance. Methods: The DQEPro (DQE Instruments Inc., London, Ontario Canada) was used to determine the MTF, NPS and DQE using an IEC compliant methodology for three different imaging modalities: conventional radiography (CsI-based detector), general-purpose radioscopy (CsI-based detector), and mammography (a-Se based detector). The radiation qualities (IEC) RQA-5 and RQA-M-2 were used for the CsI-based and a-Se-based detectors, respectively. The DQEPro alleviates some of the difficulties associated with DQE measurements by automatically positioning test devices over the detector, guiding the user through the image acquisition process and providing software for calculations. Results: A comparison of the NPS showed that the image noise of the a-Se detector was less correlated than the CsI detectors. A consistently higher performance was observed for the a-Se detector at all spatial frequencies (MTF: 0.97@0.25 cy/mm, DQE: 0.72@0.25 cy/mm) and the DQE drops off slower than for the CsI detectors. The CsI detector used for conventional radiography displayed a higher performance at low spatial frequencies compared to the CsI detector used for radioscopy (DQE: 0.65 vs 0.60@0.25 cy/mm). However, at spatial frequencies above 1.3 cy/mm, the radioscopy detector displayed better performance than the conventional radiography detector (DQE: 0.35 vs 0.24@2.00 cy/mm). Conclusion: The difference in the MTF, NPS and DQE that was observed for the two different CsI detectors and the a-Se detector reflect the imaging tasks that the different detector types are intended for. The DQEPro has made the determination and calculation of quantitative metrics of X-ray imaging detector performance substantially more convenient and accessible to undertake in a clinical setting.

  15. Kinematics of the lumbar spine : clinical significance of lateral X-rays of the lumbar spine in anteflexion and retroflexion in healthy individuals, in cases of symptomatic herniated lumbar disc diseases and of spondylolisthesis

    NARCIS (Netherlands)

    M.W. Berfelo

    1989-01-01

    textabstractAbout half of the population of the Netherlands suffers at some stage in their life from low back pain (Haanen, 1984) ; clinical examination of the lumbar spine is a matter of daily routine. X-Rays of the lumbar spine are taken in order to detect morphological changes that may be respons

  16. [PECULIARITY OF NATIONAL TUBERCULOSIS PROGRAM, JAPAN--Public-Private Mix from the Very Beginning, and Provision of X-ray Apparatus in Most General Practitioner's Clinics].

    Science.gov (United States)

    Shimao, Tadao

    2016-02-01

    Modern National Tuberculosis Program (NTP) of Japan started in 1951 when Tuberculosis (TB) Control Law was legislated, and 3 major components were health examination by tuberculin skin test (TST) and miniature X-ray, BCG vaccination and extensive use of modern TB treatment. As to the treatment program, Japan introduced Public-Private Mix (PPM) from the very beginning, and major reasons why PPM was adopted are (1) TB was then highly prevalent (Table 1), (2) TB sanatoria where many specialists are working are located in remote inconvenient places due to stigma against TB, (3) health centers (HCs) in Japan are working exclusively on prophylactic activities, and minor exceptions are treatment of sexually transmitted diseases and artificial pneumothorax for TB cases, however, as it covers on the average 100,000 population, access is not so easy in rural area, (4) Out-patients clinics mainly operated by general practitioners (GPs) are located throughout Japan, and the access is easy. Methods of TB treatment was developing rapidly in early 1950s, however, in 1952, as shown in Table 2, artificial pneumothorax and peritoneum were still used in many cases, and to fix the dosage of refill air, fluoroscopy was needed. Hence, GPs treating TB under TB Control Law had to be equipped with X-ray apparatus. To maintain the quality of TB treatment, "Criteria for TB treatment" was provided and revised taking into consideration the progress in TB treatment. If applied methods of treatment fit with the above criteria, public support is made for the cost of TB treatment. To discuss the applied treatment, TB Advisory Committee was set in each HC, composing of 5 members, director of HC, 2 TB specialists and 2 doctors recommended by the local medical association. In 1953, the first TB prevalence survey using stratified random sampling method was carried out, and the prevalence of TB requiring treatment was estimated at 3.4%, and only 21% of found cases knew their own disease, and more than

  17. SU-D-BRF-01: Applications of Photonuclear Activation of Biological Tissues in Clinical High-Energy X-Ray Beams

    International Nuclear Information System (INIS)

    Purpose: The commercial availability of high-energy accelerators opens new therapeutic opportunities for X-rays with energies in excess of 15MV. Three clinical beams (Varian 18MV, Elekta SL25, and Top Grade LA45) were compared by the production of photo-activated positron emitters in five types of biological tissues. Methods: The activation studies were performed using FLUKA2011 Monte Carlo suite with beam models designed for the three accelerators. Absolute activity density (Bq/ml) distribution in space was obtained from this study. Additionally, the temporal evolution of all activated species was monitored for cooling times up to 30 minutes. Results: The relative activation contrast of tissue pairs was evaluated for 2Gy of dose at 10cm depth for five tissues (normal, hypoxic, adipose, bone, and lung). In bone the sort-lived isotopes O-15 and P-30 dominated the activity at the early cooling stages. In all tissues 15 minutes post-irradiation the C-11 activity became dominant. Tissues with higher carbon-to-oxygen ratio in their elemental composition became clearly visible in a PET scan at longer cooling times. Radiation treatment of a lung tumor with a hypoxic core was simulated in an anthropomorphic phantom using the LA45 beam model. Increase in the PET counts by more than 50% was measured in the hypoxic volume 15 minutes post-irradiation, demonstrating the benefits of the relative activation contrast concept. Conclusion: LA45 beam is found to produce measurable activation distribution for 2Gy of dose, suitable for tissue type discrimination studies. Maximum activation contrast of 1.7 between hypoxic and normal tissues was measured in a simulated treatment. The absolute activity density values obtained from these Monte Carlo studies suggest that the window of opportunity for a PET scan exists up to 60 minutes after 2Gy of dose is deposited by 45MV X-ray beam. Lung-to-tissue activation contrast can be explored for treatment QA purposes as well

  18. SU-D-BRF-01: Applications of Photonuclear Activation of Biological Tissues in Clinical High-Energy X-Ray Beams

    Energy Technology Data Exchange (ETDEWEB)

    Veltchev, I; Fourkal, E; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States)

    2014-06-01

    Purpose: The commercial availability of high-energy accelerators opens new therapeutic opportunities for X-rays with energies in excess of 15MV. Three clinical beams (Varian 18MV, Elekta SL25, and Top Grade LA45) were compared by the production of photo-activated positron emitters in five types of biological tissues. Methods: The activation studies were performed using FLUKA2011 Monte Carlo suite with beam models designed for the three accelerators. Absolute activity density (Bq/ml) distribution in space was obtained from this study. Additionally, the temporal evolution of all activated species was monitored for cooling times up to 30 minutes. Results: The relative activation contrast of tissue pairs was evaluated for 2Gy of dose at 10cm depth for five tissues (normal, hypoxic, adipose, bone, and lung). In bone the sort-lived isotopes O-15 and P-30 dominated the activity at the early cooling stages. In all tissues 15 minutes post-irradiation the C-11 activity became dominant. Tissues with higher carbon-to-oxygen ratio in their elemental composition became clearly visible in a PET scan at longer cooling times. Radiation treatment of a lung tumor with a hypoxic core was simulated in an anthropomorphic phantom using the LA45 beam model. Increase in the PET counts by more than 50% was measured in the hypoxic volume 15 minutes post-irradiation, demonstrating the benefits of the relative activation contrast concept. Conclusion: LA45 beam is found to produce measurable activation distribution for 2Gy of dose, suitable for tissue type discrimination studies. Maximum activation contrast of 1.7 between hypoxic and normal tissues was measured in a simulated treatment. The absolute activity density values obtained from these Monte Carlo studies suggest that the window of opportunity for a PET scan exists up to 60 minutes after 2Gy of dose is deposited by 45MV X-ray beam. Lung-to-tissue activation contrast can be explored for treatment QA purposes as well.

  19. [PECULIARITY OF NATIONAL TUBERCULOSIS PROGRAM, JAPAN--Public-Private Mix from the Very Beginning, and Provision of X-ray Apparatus in Most General Practitioner's Clinics].

    Science.gov (United States)

    Shimao, Tadao

    2016-02-01

    Modern National Tuberculosis Program (NTP) of Japan started in 1951 when Tuberculosis (TB) Control Law was legislated, and 3 major components were health examination by tuberculin skin test (TST) and miniature X-ray, BCG vaccination and extensive use of modern TB treatment. As to the treatment program, Japan introduced Public-Private Mix (PPM) from the very beginning, and major reasons why PPM was adopted are (1) TB was then highly prevalent (Table 1), (2) TB sanatoria where many specialists are working are located in remote inconvenient places due to stigma against TB, (3) health centers (HCs) in Japan are working exclusively on prophylactic activities, and minor exceptions are treatment of sexually transmitted diseases and artificial pneumothorax for TB cases, however, as it covers on the average 100,000 population, access is not so easy in rural area, (4) Out-patients clinics mainly operated by general practitioners (GPs) are located throughout Japan, and the access is easy. Methods of TB treatment was developing rapidly in early 1950s, however, in 1952, as shown in Table 2, artificial pneumothorax and peritoneum were still used in many cases, and to fix the dosage of refill air, fluoroscopy was needed. Hence, GPs treating TB under TB Control Law had to be equipped with X-ray apparatus. To maintain the quality of TB treatment, "Criteria for TB treatment" was provided and revised taking into consideration the progress in TB treatment. If applied methods of treatment fit with the above criteria, public support is made for the cost of TB treatment. To discuss the applied treatment, TB Advisory Committee was set in each HC, composing of 5 members, director of HC, 2 TB specialists and 2 doctors recommended by the local medical association. In 1953, the first TB prevalence survey using stratified random sampling method was carried out, and the prevalence of TB requiring treatment was estimated at 3.4%, and only 21% of found cases knew their own disease, and more than

  20. Topological X-Rays Revisited

    Science.gov (United States)

    Lynch, Mark

    2012-01-01

    We continue our study of topological X-rays begun in Lynch ["Topological X-rays and MRI's," iJMEST 33(3) (2002), pp. 389-392]. We modify our definition of a topological magnetic resonance imaging and give an affirmative answer to the question posed there: Can we identify a closed set in a box by defining X-rays to probe the interior and without…

  1. X-ray instrumentation for SR beamlines

    CERN Document Server

    Kovalchuk, M V; Zheludeva, S I; Aleshko-Ozhevsky, O P; Arutynyan, E H; Kheiker, D M; Kreines, A Y; Lider, V V; Pashaev, E M; Shilina, N Y; Shishkov, V A

    2000-01-01

    The main possibilities and parameters of experimental X-ray stations are presented: 'Protein crystallography', 'X-ray structure analysis', 'High-precision X-ray optics', 'X-ray crystallography and material science', 'X-ray topography', 'Photoelectron X-ray standing wave' that are being installed at Kurchatov SR source by A.V. Shubnikov Institute of Crystallography.

  2. X-ray lithography sources

    International Nuclear Information System (INIS)

    Synchrotron from dipole magnets in electron storage rings has emerged as a useful source of x-rays for lithography. To meet the need for these sources numerous groups around the world have embarked on projects to design and construct storage rings for x-ray lithography. Both conventional electromagnets as well as superconducting (SC) dipoles have been incorporated into the various designs. An overview of the worldwide effort to produce commercial x-ray sources will be presented. To better illustrate the elements involved in these sources a closer examination of the Superconducting X-ray Lithography Source Project (SXLS) at BNL will be presented. 11 refs., 1 fig., 5 tabs

  3. Soft X-ray optics

    CERN Document Server

    Spiller, Eberhard A

    1993-01-01

    This text describes optics mainly in the 10 to 500 angstrom wavelength region. These wavelengths are 50 to 100 times shorter than those for visible light and 50 to 100 times longer than the wavelengths of medical x rays or x-ray diffraction from natural crystals. There have been substantial advances during the last 20 years, which one can see as an extension of optical technology to shorter wavelengths or as an extension of x-ray diffraction to longer wavelengths. Artificial diffracting structures like zone plates and multilayer mirrors are replacing the natural crystals of x-ray diffraction.

  4. X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

    This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

  5. X-ray Fluorescence Sectioning

    CERN Document Server

    Cong, Wenxiang

    2012-01-01

    In this paper, we propose an x-ray fluorescence imaging system for elemental analysis. The key idea is what we call "x-ray fluorescence sectioning". Specifically, a slit collimator in front of an x-ray tube is used to shape x-rays into a fan-beam to illuminate a planar section of an object. Then, relevant elements such as gold nanoparticles on the fan-beam plane are excited to generate x-ray fluorescence signals. One or more 2D spectral detectors are placed to face the fan-beam plane and directly measure x-ray fluorescence data. Detector elements are so collimated that each element only sees a unique area element on the fan-beam plane and records the x-ray fluorescence signal accordingly. The measured 2D x-ray fluorescence data can be refined in reference to the attenuation characteristics of the object and the divergence of the beam for accurate elemental mapping. This x-ray fluorescence sectioning system promises fast fluorescence tomographic imaging without a complex inverse procedure. The design can be ad...

  6. X-ray detectors in medical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Spahn, Martin, E-mail: martin.spahn@siemens.com [Siemens AG, Healthcare Sector, Imaging and Therapy Systems, 91301 Forchheim (Germany)

    2013-12-11

    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{sub 2}O{sub 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. Radioisotope x-ray analysis

    International Nuclear Information System (INIS)

    Radioisotope x-ray fluorescence and x-ray preferential absorption (XRA) techniques are used extensively for the analysis of materials, covering such diverse applications as analysis of alloys, coal, environmental samples, paper, waste materials, and metalliferous mineral ores and products. Many of these analyses are undertaken in the harsh environment of industrial plants and in the field. Some are continuous on-line analyses of material being processed in industry, where instantaneous analysis information is required for the control of rapidly changing processes. Radioisotope x-ray analysis systems are often tailored to a specific but limited range of applications. They are simpler and often considerably less expensive than analysis systems based on x-ray tubes. These systems are preferred to x-ray tube techniques when simplicity, ruggedness, reliability, and cost of equipment are important; when minimum size, weight, and power consumption are necessary; when a very constant and predictable x-ray output is required; when the use of high-energy x-rays is advantageous; and when short x-ray path lengths are required to minimize the absorption of low-energy x-rays in air. This chapter reviews radioisotope XRF, preferential absorption, and scattering techniques. Some of the basic analysis equations are given. The characteristics of radioisotope sources and x-ray detectors are described, and then the x-ray analytical techniques are presented. The choice of radioisotope technique for a specific application is discussed. This is followed by a summary of applications of these techniques, with a more detailed account given of some of the applications, particularly those of considerable industrial importance. 79 refs., 28 figs., 7 tabs

  8. 新生儿湿肺综合征的临床X线诊断分析%Analysis of clinical X-ray diagnosis in neonatal wet lung syndrome

    Institute of Scientific and Technical Information of China (English)

    尹忠生

    2009-01-01

    Objective To explore the clinical manifestations and characteristics of X-ray findings of wet lung syndrome. Information and methods 60 cases of newborn infants with wet lung syndrome treatment in Neonatal Division were collected (43 cases of baby boy, 17 cases of infanticide). Results:Ine early phase X-ray signs mainly showed alveolus effusion levy, and the late phase showed pulmonary vascular stagnant blood levy, while characteristics of X-ray finding of mesenchyme effusion levy was between the two course of disease. Interlobar pleural thickening and pleural effusion shaped by pleural fluid exosmosis for mesenchyme effusion.Conclusion:Wet lung syndrome, also known as transient neonatal dyspnea and respiratory distress syndrome type Ⅱ, one of the common causes of respiratory distress in early neonatal, early X-ray examination combined with clinical features, The disease can make a clear diagnosis.%目的:探讨湿肺综合征的临床表现与X线表现的特征.方法:选择新生儿科治疗的60例新生儿湿肺综合征患婴.结果:其早期X线征象以肺泡积液征为主,后期以肺血管瘀血征为主要表现.结论:湿肺综合征早期X线检查结合临床特征,本病是可以明确诊断.

  9. Common Troubleshooting of Gastrointestinal X-ray Machine in Clinical Use%胃肠X射线机在临床使用中的常见故障检修

    Institute of Scientific and Technical Information of China (English)

    丘永宏

    2015-01-01

    胃肠X射线机当前在临床上广泛使用,但是故障的检修是令人棘手的问题,其要求检修工程师必须充分了解胃肠X射线机的原理及构造,有待于在实践中不断总结和学习,以便提高判断故障的正确性和排除故障的能力。本文首先概述了胃肠X射线机的应用原则与发展,通过案例分析了胃肠X射线机在临床使用中的常见故障检修方法与效果。%Gastrointestinal X-ray machine was widely used clinical y. But troubleshooting was a tough problem, asking for deep understanding on the principle and structure of gastrointestinal X-ray machine. Summarizing and learning in practice contribute to improve the cor ectness of judging the fault and the ability of troubleshooting. This paper summarized the application principles and development of gastrointestinal X-ray machine for the first time, and the common troubleshooting methods and ef ect of Gastrointestinal X-ray machine was described in clinical use by analyzing the case.

  10. Evaluating the performance of a MOSFET dosimeter at diagnostic X-ray energies for interventional radiology.

    Science.gov (United States)

    Chida, Koichi; Inaba, Youhei; Masuyama, Hanako; Yanagawa, Isao; Mori, Issei; Saito, Haruo; Maruoka, Shin; Zuguchi, Masayuki

    2009-01-01

    For reducing the risk of skin injury during interventional radiology (IR) procedures, it has been suggested that physicians track patients' exposure doses. The metal-oxide semiconductor field effect transistor (MOSFET) dosimeter is designed to measure patient exposure dose during radiotherapy applications at megavoltage photon energies. Our purpose in this study was to evaluate the feasibility of using a MOSFET dosimeter (OneDose system) to measure patients' skin dose during exposure to diagnostic X-ray energies used in IR. The response of the OneDose system was almost constant at diagnostic X-ray energies, although the sensitivity was higher than that at megavoltage photon energies. We found that the angular dependence was minimal at diagnostic X-ray energies. The OneDose is almost invisible on X-ray images at diagnostic energies. Furthermore, the OneDose is easy to handle. The OneDose sensor performs well at diagnostic X-ray energies, although real-time measurements are not feasible. Thus, the OneDose system may prove useful in measuring patient exposure dose during IR. PMID:20821130

  11. New intraoral x-ray fluorographic imaging for dentistry

    International Nuclear Information System (INIS)

    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

  12. Clinical and Laboratory Findings in Patients With Acute Respiratory Symptoms That Suggest the Necessity of Chest X-ray for Community-Acquired Pneumonia

    International Nuclear Information System (INIS)

    Pneumonia is a common illness in all parts of the world and is considered as a major cause of death among all age groups. Nevertheless, only about 5% of patients referring to their primary care physicians with acute respiratory symptoms will develop pneumonia. This study was performed to derive practical criteria for performing chest radiographs for the evaluation of community-acquired pneumonia (CAP). A total of 420 patients with acute respiratory symptoms and positive findings on chest radiograph were evaluated from December 2008 to December 2009. The subjects were referred to outpatient clinics or emergency departments of Birjand's medical university hospitals, Iran, and were enrolled as positive cases. A checklist was completed for each patient including their demographic information, clinical signs and symptoms (cough, sputum production, dyspnea, chest pain, fever, tachycardia, and tachypnea), abnormal findings in pulmonary auscultation and laboratory findings (erythrocyte sedimentation rate, C-reactive protein levels, and white blood cell count). An equal number of age-matched individuals with acute respiratory symptoms, but insignificant findings on chest radiography, were included as the control group. Finally, the diagnostic values of different findings were compared. The data showed that vital signs and physical examination findings are useful screening parameters for predicting chest radiograph findings in outpatient settings. Therefore, by implementing a prediction rule, we would be able to determine which patients would benefit from a chest X-Ray (sensitivity, 94% and specificity, 57%). This study's findings suggest that requesting chest radiographs might not be necessary in patients with acute respiratory symptoms unless the vital signs and/or physical examination findings are abnormal. Considering the 94% sensitivity of this rule for predicting CAP, a chest radiograph is required for patients with unreliable follow-ups or moderate to high

  13. 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 ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ...

  14. X-ray diagnostic equipment

    International Nuclear Information System (INIS)

    An X-ray tube is connected to several different image processing devices in X-ray diagnostic equipment. Only a single organ selector is allocated to it, for which the picture parameters for each image processing device are selected. The choice of the correct combination of picture parameters is made by means of a selector switch. (DG)

  15. X-ray tube arrangement

    International Nuclear Information System (INIS)

    An x-ray tube is described incorporating an elongated target/ anode over which the electron beam is deflected and from which x-rays are emitted. Improved methods of monitoring and controlling the amplitude of the beam deflection are presented. (U.K.)

  16. The clinical value of the mammography X-ray, ultrasound and MRI for the qualitative diagnosis of breast cancer%钼靶X射线、超声及MRI对乳腺癌诊断的应用价值

    Institute of Scientific and Technical Information of China (English)

    赵军

    2014-01-01

    Objective:To evaluate the diagnostic value of the mammography X-ray, ultrasound and MRI for breast cancer, expected to provide a reference for the clinical diagnosis of these diseases. Methods:117 cases patients with suspected breast cancer were the objects of the study, compared the results of the detection with mammography X-ray, ultrasound and MRI between the results of pathological examination, to investigate the diagnostic ability of different image means for all types of breast disease.Results:The sensitivity, accuracy of MRI for breast cancer were better than X-ray mammography and ultrasound, but the speciifcity was similar with X-ray mammography. Compared ultrasound, the specificity, positive predictive value of X-ray mammography was much higher, but had no advantage in the other parameters related with diagnostic capabilities.Conclusions:Mammography X-ray, ultrasound and MRI have their own advantages and disadvantages for the diagnosis of breast diseases, but the mammography X-ray can be as the preferred means for the ifrst diagnosis of breast cancer, and multiple imaging means could be joint based on the needs of clinical diagnosis.%目的:探讨钼靶X射线、超声及MRI对乳腺癌的临床诊断价值。方法:以117例疑似乳腺癌患者为研究对象,将钼靶X射线、超声及MRI检查结果与病理诊断结果对比,考察不同影像手段对各类乳腺疾病的诊断能力。结果:MRI对乳腺癌的敏感性、准确度等均优于钼靶X射线和超声,但特异性与钼靶X射线相当。与超声相比,钼靶X射线的特异性、阳性预测值较高,但在其他诊断能力相关的参数方面则无优势。结论:钼靶X射线、超声及MRI在诊断乳腺疾病方面各有优劣,但钼靶X射线可作为乳腺癌临床初诊的首选手段,临床确诊时可联用多种影像手段。

  17. Differential X-ray phase contrast tomography of Alzheimer plaques in mouse models: perspectives for drug development and clinical imaging techniques

    Science.gov (United States)

    Pinzer, B. R.; Cacquevel, M.; Modregger, P.; Thuering, T.; Stampanoni, M.

    2013-05-01

    Alzheimer's disease (AD) is a looming threat on an ever-ageing population, with devastating effects on the human intellect. A particular characteristic lesion — the extracellular amyloid plaque — accumulates in the brain of AD patients during the course of the disease, and could therefore be used to monitor the progression of the disease, years before the first neurological symptoms appear. In addition, strategies for drug intervention in AD are often based on amyloid reduction, since amyloid plaques are hypothesized to be involved in a chain of reactions leading to the death of neurons. Developments in both fields would benefit from a microscopic technique that is capable of single plaque imaging, ideally in 3D. While such a non-destructive, single-plaque imaging technique does not yet exist for humans, it has been recently shown that synchrotron based differential X-ray phase contrast imaging can be used to visualize individual plaques at μm resolution in mouse models of AD ex-vivo. This method, which relies on a grating interferometer to measure refraction angles induced by fluctuations in the refractive index, yields a precise three-dimensional distribution of single plaques. These data could not only improve the understanding of the evolution of AD or the effectiveness of drugs, but could also help to improve reliable markers for current and future non-invasive clinical imaging techniques. In particular, validation of PET markers with small animal models could be rapidly carried out by co-registration of PET and DPC signals.

  18. The clinical feasibility and performance of an orthogonal X-ray imaging system for image-guided radiotherapy in nasopharyngeal cancer patients: Comparison with cone-beam CT.

    Science.gov (United States)

    Zhao, Li-Rong; Zhou, Yi-Bing; Li, Guang-Hui; Li, Qi-Ming; Yang, Ding-Qiang; Li, Han-Xu; Wan, Jiu-Qing; Sun, Jian-Guo

    2016-01-01

    The demand for greater accuracy of intensity-modulated radiotherapy (IMRT) has driven the development of more advanced verification systems for image-guided radiotherapy (IGRT). The purpose of this study is to investigate setup discrepancies measured between an orthogonal X-ray guidance system (XGS-10) and cone-beam computed tomography (CBCT) of Varian in the IMRT of patients with nasopharyngeal cancer (NPC). The setup errors measured by XGS-10 and CBCT at the treatment unit with respect to the planning CTs were recorded for 30 patients with NPC. The differences in residual setup errors between XGS-10 system and CBCT were computed and quantitatively analyzed. The time of image acquisition and image registration was recorded. The radiation doses delivered by CBCT and XGS-10 were measured using PTW0.6CC ionization chambers and a water phantom. The differences between setup errors measured by the XGS-10 system and CBCT were generally <1.5 mm for translations, indicating a reasonably good agreement between the two systems for patients with NPC in the translation directions of A-P (P = 0.856), L-R (P = 0.856) and S-I (P = 0.765). Moreover, compared with CBCT, XGS-10 took much shorter image acquisition and registration time (P <0.001) and delivered only a small fraction of extra radiation dose to the patients (P <0.001). These results indicate that XGS-10 offers high localization accuracy similar to CBCT and additional benefits including prompt imaging process, low imaging radiation exposure, real time monitoring, which therefore represents a potential attractive alternative to CBCT for clinical use. PMID:26703446

  19. X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kalender, Willi A [Institute of Medical Physics, University Erlangen-Nuernberg, Henkestr. 91, D-91052 Erlangen (Germany)

    2006-07-07

    X-ray computed tomography (CT), introduced into clinical practice in 1972, was the first of the modern slice-imaging modalities. To reconstruct images mathematically from measured data and to display and to archive them in digital form was a novelty then and is commonplace today. CT has shown a steady upward trend with respect to technology, performance and clinical use independent of predictions and expert assessments which forecast in the 1980s that it would be completely replaced by magnetic resonance imaging. CT not only survived but exhibited a true renaissance due to the introduction of spiral scanning which meant the transition from slice-by-slice imaging to true volume imaging. Complemented by the introduction of array detector technology in the 1990s, CT today allows imaging of whole organs or the whole body in 5 to 20 s with sub-millimetre isotropic resolution. This review of CT will proceed in chronological order focussing on technology, image quality and clinical applications. In its final part it will also briefly allude to novel uses of CT such as dual-source CT, C-arm flat-panel-detector CT and micro-CT. At present CT possibly exhibits a higher innovation rate than ever before. In consequence the topical and most recent developments will receive the greatest attention. (review)

  20. Phase-contrast X-ray imaging of breast

    Energy Technology Data Exchange (ETDEWEB)

    Keyrilaeinen, Jani; Tenhunen, Mikko (Dept. of Physics, HUCH Cancer Center, Helsinki Univ. Central Hospital, Helsinki (Finland)), e-mail: jani.keyrilainen@hus.fi; Bravin, Alberto (Bio-medical Beamline ID17, European Synchrotron Radiation Facility, Grenoble (France)); Fernandez, Manuel (High Brilliance Beamline ID2, European Synchrotron Radiation Facility, Grenoble (France)); Virkkunen, Pekka (Dept. of Radiology, HUCH Cancer Center, Helsinki Univ. Central Hospital, Helsinki (Finland)); Suortti, Pekka (Dept. of Physics, Univ. of Helsinki, Helsinki (Finland))

    2010-10-15

    When an X-ray wave traverses an object, its amplitude and phase change, resulting in attenuation, interference, and refraction, and in phase-contrast X-ray imaging (PCI) these are converted to intensity changes. The relative change of the X-ray phase per unit path length is even orders of magnitude larger than that of the X-ray amplitude, so that the image contrast based on variation of the X-ray phase is potentially much stronger than the contrast based on X-ray amplitude (absorption contrast). An important medical application of PCI methods is soft-tissue imaging, where the absorption contrast is inherently weak. It is shown by in vitro examples that signs of malignant human breast tumor are enhanced in PCI images. Owing to the strong contrast, the radiation dose can be greatly reduced, so that a high-resolution phase-contrast X-ray tomography of the breast is possible with about 1 mGy mean glandular dose. Scattered radiation carries essential information on the atomic and molecular structure of the object, and particularly small-angle X-ray scattering can be used to trace cancer. The imaging methods developed at the synchrotron radiation facilities will become available in the clinical environment with the ongoing development of compact radiation sources, which produce intense X-ray beams of sufficient coherence. Several developments that are under way are described here

  1. Phase-contrast X-ray imaging of breast.

    Science.gov (United States)

    Keyriläinen, Jani; Bravin, Alberto; Fernández, Manuel; Tenhunen, Mikko; Virkkunen, Pekka; Suortti, Pekka

    2010-10-01

    When an X-ray wave traverses an object, its amplitude and phase change, resulting in attenuation, interference, and refraction, and in phase-contrast X-ray imaging (PCI) these are converted to intensity changes. The relative change of the X-ray phase per unit path length is even orders of magnitude larger than that of the X-ray amplitude, so that the image contrast based on variation of the X-ray phase is potentially much stronger than the contrast based on X-ray amplitude (absorption contrast). An important medical application of PCI methods is soft-tissue imaging, where the absorption contrast is inherently weak. It is shown by in vitro examples that signs of malignant human breast tumor are enhanced in PCI images. Owing to the strong contrast, the radiation dose can be greatly reduced, so that a high-resolution phase-contrast X-ray tomography of the breast is possible with about 1 mGy mean glandular dose. Scattered radiation carries essential information on the atomic and molecular structure of the object, and particularly small-angle X-ray scattering can be used to trace cancer. The imaging methods developed at the synchrotron radiation facilities will become available in the clinical environment with the ongoing development of compact radiation sources, which produce intense X-ray beams of sufficient coherence. Several developments that are under way are described here. PMID:20799921

  2. Semiconductor X-ray detectors

    CERN Document Server

    Lowe, Barrie Glyn

    2014-01-01

    Identifying and measuring the elemental x-rays released when materials are examined with particles (electrons, protons, alpha particles, etc.) or photons (x-rays and gamma rays) is still considered to be the primary analytical technique for routine and non-destructive materials analysis. The Lithium Drifted Silicon (Si(Li)) X-Ray Detector, with its good resolution and peak to background, pioneered this type of analysis on electron microscopes, x-ray fluorescence instruments, and radioactive source- and accelerator-based excitation systems. Although rapid progress in Silicon Drift Detectors (SDDs), Charge Coupled Devices (CCDs), and Compound Semiconductor Detectors, including renewed interest in alternative materials such as CdZnTe and diamond, has made the Si(Li) X-Ray Detector nearly obsolete, the device serves as a useful benchmark and still is used in special instances where its large, sensitive depth is essential. Semiconductor X-Ray Detectors focuses on the history and development of Si(Li) X-Ray Detect...

  3. X-ray diffraction apparatus

    International Nuclear Information System (INIS)

    The invention provides an x-ray diffraction apparatus permitting the rotation of the divergence sit in conjunction with the rotation of the x-ray irradiated specimen, whereby the dimensions of the x-ray irradiated portion of the specimen remain substantially constant during the rotation of the specimen. In a preferred embodiment, the divergence slit is connected to a structural element linked with a second structural element connected to the specimen such that the divergence slit rotates at a lower angular speed than the specimen

  4. Clinical importance of digitized chest X-ray for detection of pulmonary infiltrations in bone marrow transplant patients during aplasia; Wertigkeit der digitalen Thoraxaufnahme bei der Detektion von Lungeninfiltraten knochenmarktransplantierten Patienten in der Aplasie

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.; Maas, R.; Steiner, P.; Kramer, J.; Bumann, D.; Buecheler, E. [Universitaetskrankenhaus Eppendorf, Hamburg (Germany). Abt. fuer Roentgendiagnostik; Zander, A.R. [Universitaetskrankenhaus Eppendorf, Hamburg (Germany). Zentrum fuer Knochenmarktransplantation

    1999-10-01

    Purpose: Evaluation of digitized chest X-ray for the detection of pulmonary infiltrations in bone marrow transplant patients during aplasia. Methods: Digitized chest X-rays of 40 patients (21 female, 19 male) with 'Fever of unknown origin' (FUO) were evaluated concerning radiological signs of pulmonary infiltrations and correlated to clinical findings, blood chemistry, microbiology and bronchoscopy. Additionally, an individual risk profile was established. Results: In 11/40 patients pulmonary infiltrations were detected in digitized chest X-rays (group 1). 10/11 developed an infectious pulmonary infiltration. 29/40 patients developed no pulmonary infiltration (group 2). When fever increased for the first time (initial chest X-ray) a sensitivity, specificity, positive and negative predictive value of 46%, 86%, 56%, 81% and for the chest X-rays in process of 61%, 79%, 68% and 73% was found. C-reactive protein and temperature increase occured statistically significantly earlier (p<0.05) in group 1 compared to group 2. The average latency of digital chest X-rays in comparison to c-reactive protein and temperature increase was 6 days. The incidence of risk factors was significantly higher in group 1 in comparison to group 2 (p<0.05). Conclusion: Digitized chest X-rays are not a reliable method for primary detection of pulmonary infiltrations after bone marrow transplantation. Individual risk factors have to be taken into consideration to indicate further diagnostic methods such as computed tomography at an earlier time. (orig.) [German] Ziel: Wertigkeit der digitalen Thoraxaufnahme bei der Detektion pulmonaler Infiltrate bei knochenmarktransplantierten Patienten in der Aplasie. Methoden: Digitale Thoraxaufnahmen von 40 Patienten (21 Frauen, 19 Maenner) in Aplasie mit Fieber unklarer Genese wurden nach Zeichen pulmonaler Infiltrate ausgewertet und mit klinischen, laborchemischen, mikrobiologischen und bronchoskopischen Befunden korreliert. Zusaetzlich wurde ein

  5. Clinical analysis of small peripheral lung cancer diagnostic X-ray and CT%周围型小肺癌X线与CT诊断方法临床分析

    Institute of Scientific and Technical Information of China (English)

    张青春

    2014-01-01

    目的:探讨X线与CT诊断的影像学表现对周围型小肺癌早期诊断率的临床意义。方法将89例周围型小肺癌患者分别行X 线片检查和螺旋CT 薄层增强扫描,并分析所显现的影像学特征。结果 CT 检查阳性率以边缘不规分叶征67例(51.69%)最多,显著高于X 线片检查的46例(75.28%),两者比较,差异有统计学意义(P<0.05)。CT 增强扫描对周围型小肺癌的诊断优于X 线片检查。结论 CT 薄层增强扫描可提高周围型小肺癌的早期诊断率。%Objective To discuss clinical significance of imaging X-ray and CT diagnosis for peripheral small lung cancer early diagnosis.Methods The 89 cases of small peripheral lung cancer patients were performed X-ray examination and thin enhanced spiral CT scan, and imaging analysis revealed special.Results CT scan-positive rate to edge irregular lobulation 67 cases (51.69%) the most, significantly higher than the 46 cases of X-ray inspection (75.28%), respectively, the difference was statistically significant(P<0.05). Contrast-enhanced CT scan of small peripheral lung cancer diagnosis than X-ray examination.Conclusion X-rays and CT scans can improve thin enhancement of small peripheral lung cancer early diagnosis.

  6. Duodenal X-ray diagnostics

    International Nuclear Information System (INIS)

    The publication provides an overview of duodenal X-ray diagnostics with the aid of barium meals in 1362 patients. The introducing paragraphs deal with the topographic anatomy of the region and the methodics of X-ray investigation. The chapter entitled ''processes at the duodenum itself'' describes mainly ulcers, diverticula, congenital anomalies, tumors and inflammations. The neighbourhood processes comprise in the first place diseases having their origin at the pancreas and bile ducts. As a conclusion, endoscopic rectograde cholangio-pancreaticography and percutaneous transhepatic cholangiography are pointed out as advanced X-ray investigation methods. In the annex of X-ray images some of the described phenomena are shown in exemplary manner. (orig./MG)

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... like a photographic negative). Today, most images are digital files that are stored electronically. These stored images ... and places the x-ray film holder or digital recording plate under the table in the area ...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to ... See the Safety page for more information about pregnancy and x-rays. top of page What does ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the baby. See the Safety page for more information about pregnancy and x-rays. top of page ... procedure varies. See the Safety page for more information about radiation dose. Women should always inform their ...

  10. X-ray microtomographic scanners

    Energy Technology Data Exchange (ETDEWEB)

    Syryamkin, V. I., E-mail: klestov-simon@mail.ru; Klestov, S. A., E-mail: klestov-simon@mail.ru [National Research Tomsk State University, Tomsk, 634050 (Russian Federation)

    2015-11-17

    The article studies the operating procedures of an X-ray microtomographic scanner and the module of reconstruction and analysis 3D-image of a test sample in particular. An algorithm for 3D-image reconstruction based on image shadow projections and mathematical methods of the processing are described. Chapter 1 describes the basic principles of X-ray tomography and general procedures of the device developed. Chapters 2 and 3 are devoted to the problem of resources saving by the system during the X-ray tomography procedure, which is achieved by preprocessing of the initial shadow projections. Preprocessing includes background noise removing from the images, which reduces the amount of shadow projections in general and increases the efficiency of the group shadow projections compression. In conclusion, the main applications of X-ray tomography are presented.

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and ... in the typical diagnostic range for this exam. Risks There is always a slight chance of cancer ...

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... can be taken to the patient in a hospital bed or the emergency room. The x-ray ... and international radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern ...

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the patient in a hospital bed or the emergency room. The x-ray tube is connected to ... equipment is relatively inexpensive and widely available in emergency rooms, physician offices, ambulatory care centers, nursing homes ...

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... or in bones. top of page How should I prepare? Most bone x-rays require no special ... to 10 minutes. top of page What will I experience during and after the procedure? A bone ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the body absorb the x-rays in varying degrees. Dense bone absorbs much of the radiation while ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  16. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Intra-oral dental X-ray apparatus for panoramic dental radiography is described in detail. It comprises an electron gun having an elongated tubular target carrier extending into the patient's mouth. The carrier supports an inclined target for direction of an X-ray pattern towards a film positioned externally of the patient's mouth. Image definition is improved by a focusing anode which focuses the electron beam into a sharp spot (0.05 to 0.10 mm diameter) on the target. The potential on the focusing anode is adjustable to vary the size of the spot. An X-ray transmitting ceramic (oxides of Be, Al and Si) window is positioned adjacent to the front face of the target. The electron beam can be magnetically deflected to change the X-ray beam direction. (author)

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection organizations continually review and update the technique standards ...

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... technologist, an individual specially trained to perform radiology examinations, positions the patient on the x-ray table ... bone is forming), for comparison purposes. When the examination is complete, you may be asked to wait ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... replacement and fracture reductions. look for injury, infection, arthritis , abnormal bone growths and bony changes seen in ... injuries, including fractures, and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely ...

  20. X-Ray Assembler Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Federal regulations require that an assembler who installs one or more certified components of a diagnostic x-ray system submit a report of assembly. This database...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... a large photographic negative). Today, most images are digital files that are stored electronically. These stored images ... and places the x-ray film holder or digital recording plate under the table in the area ...

  2. Accelerator x-ray sources

    CERN Document Server

    Talman, Richard

    2007-01-01

    This first book to cover in-depth the generation of x-rays in particle accelerators focuses on electron beams produced by means of the novel Energy Recovery Linac (ERL) technology. The resulting highly brilliant x-rays are at the centre of this monograph, which continues where other books on the market stop. Written primarily for general, high energy and radiation physicists, the systematic treatment adopted by the work makes it equally suitable as an advanced textbook for young researchers.

  3. X-ray fluorescence holography

    CERN Document Server

    Hayashi, K; Takahashi, Y

    2003-01-01

    X-ray fluorescence holography (XFH) is a new structural analysis method of determining a 3D atomic arrangement around fluorescing atoms. We developed an XFH apparatus using advanced X-ray techniques and succeeded in obtaining high-quality hologram data. Furthermore, we introduced applications to the structural analysis of a thin film and the environment around dopants and, discussed the quantitative analysis of local lattice distortion. (author)

  4. Electromechanical x-ray generator

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Scott A; Platts, David; Sorensen, Eric B

    2016-05-03

    An electro-mechanical x-ray generator configured to obtain high-energy operation with favorable energy-weight scaling. The electro-mechanical x-ray generator may include a pair of capacitor plates. The capacitor plates may be charged to a predefined voltage and may be separated to generate higher voltages on the order of hundreds of kV in the AK gap. The high voltage may be generated in a vacuum tube.

  5. X-ray diagnostic apparatus

    International Nuclear Information System (INIS)

    A falling load type X-ray diagnostic apparatus comprises a low voltage power source, AC-DC converting means connected to the low voltage power source so as to apply a rectified low DC voltage, chopping means connected to the AC-DC converting means and chopping said DC voltage into a low AC voltage, high voltage applying means for transforming said low AC voltage into a high AC voltage, said high AC voltage being applied as a tube voltage to an X-ray tube from which X-rays are irradiated toward an object to be examined, means for controlling a filament heating power of the X-ray tube, programming means for supplying a control signal to said filament heating control means so as to reduce the emission current of said X-ray tube during the irradiation, and chopper control means for controlling the chopping ratio of said chopping means by evaluating said rectified DC voltage with a preset tube voltage generated in said programming means, said programming means compensating said tube voltage by receiving said control signal in such a manner that said tube voltage is maintained substantially constant during the irradiation by varying said preset tube voltage so as to control the chopping ratio based upon the reduction of the filament heating power for the X-ray tube

  6. Low energy (soft) x rays

    International Nuclear Information System (INIS)

    Dosimetry of low-energy (soft) X rays produced by the SOFTEX Model CMBW-2 was performed using Nuclear Associates Type 30 - 330 PTW, Exradin Type A2, and Shonka-Wyckoff ionization chambers with a Keithley Model 602 electrometer. Thermoluminescent (BeO chip) dosimeters were used with a Harshaw Detector 2000-A and Picoammeter-B readout system. Beam quality measurements were made using aluminum absorbers; exposure rates were assessed by the current of the X-ray tube and by exposure times. Dose distributions were established, and the average factors for non-uniformity were calculated. The means of obtaining accurate absorbed and exposed doses using these methods are discussed. Survival of V79 cells was assessed by irradiating them with soft X rays, 200 kVp X rays, and 60Co gamma rays. The relative biological effectiveness (RBE) values for soft X rays with 0, 0.2, 0.7 mm added thicknesses of aluminum were 1.6, which were compared to 60Co. The RBE of 200 kVp X rays relative to 60Co was 1.3. Results of this study are available for reference in future RERF studies of cell survival. (author)

  7. Center for X-Ray Optics, 1992

    International Nuclear Information System (INIS)

    This report discusses the following topics: Center for X-Ray Optics; Soft X-Ray Imaging wit Zone Plate Lenses; Biological X-Ray microscopy; Extreme Ultraviolet Lithography for Nanoelectronic Pattern Transfer; Multilayer Reflective Optics; EUV/Soft X-ray Reflectometer; Photoemission Microscopy with Reflective Optics; Spectroscopy with Soft X-Rays; Hard X-Ray Microprobe; Coronary Angiography; and Atomic Scattering Factors

  8. X-ray Echo Spectroscopy

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-01

    X-ray echo spectroscopy, a counterpart of neutron spin echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a pointlike x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1-0.02 meV ultrahigh-resolution IXS applications (resolving power >108 ) with broadband ≃5 - 13 meV dispersing systems are introduced featuring more than 103 signal enhancement. The technique is general, applicable in different photon frequency domains.

  9. X-ray echo spectroscopy

    CERN Document Server

    Shvyd'ko, Yuri

    2015-01-01

    X-ray echo spectroscopy, a counterpart of neutron spin-echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a point-like x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x-rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1--0.02-meV ultra-high-resolution IXS applications (resolving power $> 10^8$) with broadband $\\simeq$~5--13~meV dispersing systems are introduced featuring more than $10^3$ signal e...

  10. X-ray Echo Spectroscopy.

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-26

    X-ray echo spectroscopy, a counterpart of neutron spin echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a pointlike x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1-0.02 meV ultrahigh-resolution IXS applications (resolving power >10^{8}) with broadband ≃5-13  meV dispersing systems are introduced featuring more than 10^{3} signal enhancement. The technique is general, applicable in different photon frequency domains.

  11. Low-Dose Megavoltage Cone-Beam CT imaging using Thick, Segmented Scintillators

    OpenAIRE

    El-Mohri, Youcef; Antonuk, Larry E.; Zhao, Qihua; Choroszucha, Richard B.; Jiang, Hao; Liu, Langechuan

    2011-01-01

    Megavoltage, cone-beam computed tomography (MV CBCT) employing an electronic portal imaging device (EPID) is a highly promising technique for providing soft-tissue visualization in image-guided radiotherapy. However, current EPIDs based on active matrix flat-panel imagers (AMFPIs), which are regarded as the gold standard for portal imaging and referred to as conventional MV AMFPIs, require high radiation doses to achieve this goal due to poor x-ray detection efficiency (~2% at 6 MV). To overc...

  12. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Intra-oral X-ray apparatus which reduces the number of exposures necessary to obtain panoramic dental radiographs is described in detail. It comprises an electron gun, a tubular target carrier projecting from the gun along the beam axis and carrying at its distal end a target surrounded by a shield of X-ray opaque material. This shield extends forward and laterally of the target and has surfaces which define a wedge or cone-shaped radiation pattern delimited vertically by the root tips of the patient's teeth. A film holder is located externally of the patient's mouth. A disposable member can fit on the target carrier to depress the patient's tongue out of the radiation pattern and to further shield the roof of the mouth. The electron beam can be magnetically deflected to change the X-ray beam direction. (author)

  13. X-ray imaging: Perovskites target X-ray detection

    Science.gov (United States)

    Heiss, Wolfgang; Brabec, Christoph

    2016-05-01

    Single crystals of perovskites are currently of interest to help fathom fundamental physical parameters limiting the performance of perovskite-based polycrystalline solar cells. Now, such perovskites offer a technology platform for optoelectronic devices, such as cheap and sensitive X-ray detectors.

  14. Exploring coherent phenomena and energy discrimination in X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, Thomas

    2011-05-04

    Conventional X-ray imaging is based on the generation of photons in materials that are selected for different applications according to their densities, dimensions, and atomic numbers. The photons produced in these targets are commonly detected by measuring the integrated amount of energy released in films or digital imaging systems. This thesis aims at extending these two paradigms. First, it is shown that the use of single-crystalline, i.e. well-ordered targets, can significantly soften photon spectra created by megavoltage electrons when compared to usual targets. The reason for this is an effect called ''coherent bremsstrahlung''. It is shown that this type of radiation bears the potential of increasing the quality of megavoltage images and reducing radiation dose for image guided radiotherapy. Second, new spectroscopic pixel detectors of the Medipix2 family operated with cadmium telluride sensors are characterised and thus potential benefits and difficulties for X-ray imaging are investigated. Besides describing in detail how to calibrate these detectors, emphasis is placed on determining their energy responses, modulation transfer functions, and detective quantum efficiencies. Requirements for photon counting megavoltage imaging are discussed. The detector systems studied are finally used to perform spectral computed tomography and to illustrate the benefits of energy discrimination for coherent scatter imaging. (orig.)

  15. Exploring coherent phenomena and energy discrimination in X-ray imaging

    International Nuclear Information System (INIS)

    Conventional X-ray imaging is based on the generation of photons in materials that are selected for different applications according to their densities, dimensions, and atomic numbers. The photons produced in these targets are commonly detected by measuring the integrated amount of energy released in films or digital imaging systems. This thesis aims at extending these two paradigms. First, it is shown that the use of single-crystalline, i.e. well-ordered targets, can significantly soften photon spectra created by megavoltage electrons when compared to usual targets. The reason for this is an effect called ''coherent bremsstrahlung''. It is shown that this type of radiation bears the potential of increasing the quality of megavoltage images and reducing radiation dose for image guided radiotherapy. Second, new spectroscopic pixel detectors of the Medipix2 family operated with cadmium telluride sensors are characterised and thus potential benefits and difficulties for X-ray imaging are investigated. Besides describing in detail how to calibrate these detectors, emphasis is placed on determining their energy responses, modulation transfer functions, and detective quantum efficiencies. Requirements for photon counting megavoltage imaging are discussed. The detector systems studied are finally used to perform spectral computed tomography and to illustrate the benefits of energy discrimination for coherent scatter imaging. (orig.)

  16. X-ray hot plasma diagnostics

    International Nuclear Information System (INIS)

    X-ray plasma emission study is powerful diagnostic tool of hot plasmas. In this review article the main techniques of X-ray plasma emission measurement are shortly presented: X-ray spectrometry using absorbent filters, crystal and grating spectrometers, imaging techniques using pinhole cameras, X-ray microscopes and Fresnel zone plate cameras, X-ray plasma emission calorimetry. Advances in these techniques with examples for different hot plasma devices are also presentes. (author)

  17. X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    The seventh edition of Philips' Review of Literature on x-ray fluorescence spectrometry starts with a list of conference proceedings on the subject, organised by the Philips organisation at regular intervals in various European countries. It is followed by a list of bulletins. The bibliography is subdivided according to spectra, equipment, applications and absorption analysis

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Images related to X-ray (Radiography) - Bone About this Site RadiologyInfo.org is produced by: Please note ... you can search the ACR-accredited facilities database . This website does not provide cost information. The costs ...

  19. X-ray backscatter imaging

    Science.gov (United States)

    Dinca, Dan-Cristian; Schubert, Jeffrey R.; Callerame, J.

    2008-04-01

    In contrast to transmission X-ray imaging systems where inspected objects must pass between source and detector, Compton backscatter imaging allows both the illuminating source as well as the X-ray detector to be on the same side of the target object, enabling the inspection to occur rapidly and in a wide variety of space-constrained situations. A Compton backscatter image is similar to a photograph of the contents of a closed container, taken through the container walls, and highlights low atomic number materials such as explosives, drugs, and alcohol, which appear as especially bright objects by virtue of their scattering characteristics. Techniques for producing X-ray images based on Compton scattering will be discussed, along with examples of how these systems are used for both novel security applications and for the detection of contraband materials at ports and borders. Differences between transmission and backscatter images will also be highlighted. In addition, tradeoffs between Compton backscatter image quality and scan speed, effective penetration, and X-ray source specifications will be discussed.

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone ...

  1. X-Ray Diffractive Optics

    Science.gov (United States)

    Dennis, Brian; Li, Mary; Skinner, Gerald

    2013-01-01

    X-ray optics were fabricated with the capability of imaging solar x-ray sources with better than 0.1 arcsecond angular resolution, over an order of magnitude finer than is currently possible. Such images would provide a new window into the little-understood energy release and particle acceleration regions in solar flares. They constitute one of the most promising ways to probe these regions in the solar atmosphere with the sensitivity and angular resolution needed to better understand the physical processes involved. A circular slit structure with widths as fine as 0.85 micron etched in a silicon wafer 8 microns thick forms a phase zone plate version of a Fresnel lens capable of focusing approx. =.6 keV x-rays. The focal length of the 3-cm diameter lenses is 100 microns, and the angular resolution capability is better than 0.1 arcsecond. Such phase zone plates were fabricated in Goddard fs Detector Development Lab. (DDL) and tested at the Goddard 600-microns x-ray test facility. The test data verified that the desired angular resolution and throughput efficiency were achieved.

  2. X-ray film processing

    International Nuclear Information System (INIS)

    X-ray films have to be highly sensitive, for radiation protection reasons. The films used in radiology are coated on both sides with a photosensitive emulsion. This applies to all dental films. Their properties and the development of the different exposed films are explained. (DG)

  3. X-rays and magnetism.

    Science.gov (United States)

    Fischer, Peter; Ohldag, Hendrik

    2015-09-01

    Magnetism is among the most active and attractive areas in modern solid state physics because of intriguing phenomena interesting to fundamental research and a manifold of technological applications. State-of-the-art synthesis of advanced magnetic materials, e.g. in hybrid structures paves the way to new functionalities. To characterize modern magnetic materials and the associated magnetic phenomena, polarized x-rays have emerged as unique probes due to their specific interaction with magnetic materials. A large variety of spectroscopic and microscopic techniques have been developed to quantify in an element, valence and site-sensitive way properties of ferro-, ferri-, and antiferromagnetic systems, such as spin and orbital moments, and to image nanoscale spin textures and their dynamics with sub-ns time and almost 10 nm spatial resolution. The enormous intensity of x-rays and their degree of coherence at next generation x-ray facilities will open the fsec time window to magnetic studies addressing fundamental time scales in magnetism with nanometer spatial resolution. This review will give an introduction into contemporary topics of nanoscale magnetic materials and provide an overview of analytical spectroscopy and microscopy tools based on x-ray dichroism effects. Selected examples of current research will demonstrate the potential and future directions of these techniques.

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest ... evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... for more information about pregnancy and x-rays. A Word About Minimizing Radiation Exposure Special care is ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  7. High-Resolution X-ray Emission and X-ray Absorption Spectroscopy

    OpenAIRE

    de Groot, F. M. F.

    2001-01-01

    In this review, high-resolution X-ray emission and X-ray absorption spectroscopy will be discussed. The focus is on the 3d transition-metal systems. To understand high-resolution X-ray emission and reso-nant X-ray emission, it is first necessary to spend some time discussing the X-ray absorption process. Section II discusses 1s X-ray absorption, i.e., the K edges, and section III deals with 2p X-ray absorption, the L edges. X-ray emission is discussed in, respectively, the L edges. X-ray emis...

  8. High-Resolution X-ray Emission and X-ray Absorption Spectroscopy

    NARCIS (Netherlands)

    Groot, F.M.F. de

    2001-01-01

    In this review, high-resolution X-ray emission and X-ray absorption spectroscopy will be discussed. The focus is on the 3d transition-metal systems. To understand high-resolution X-ray emission and reso-nant X-ray emission, it is first necessary to spend some time discussing the X-ray absorption pro

  9. 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)

    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)

  10. Center for X-Ray Optics, 1986

    International Nuclear Information System (INIS)

    The Center for X-Ray Optics has made substantial progress during the past year on the development of very high resolution x-ray technologies, the generation of coherent radiation at x-ray wavelengths, and, based on these new developments, had embarked on several scientific investigations that would not otherwise have been possible. The investigations covered in this report are topics on x-ray sources, x-ray imaging and applications, soft x-ray spectroscopy, synchrotron radiation, advanced light source and magnet structures for undulators and wigglers

  11. Soft x-ray tomoholography

    International Nuclear Information System (INIS)

    We demonstrate an x-ray imaging method that combines Fourier transform holography with tomography (‘tomoholography’) for three-dimensional (3D) microscopic imaging. A 3D image of a diatom shell with a spatial resolution of 140 nm is presented. The experiment is realized by using a small gold sphere as the reference wave source for holographic imaging. This setup allows us to rotate the sample and to collect a number of 2D projections for tomography. (paper)

  12. Soft x-ray tomoholography

    OpenAIRE

    Guehrs, E.; Stadler, A.M.; Flewett, S.; Frömmel, S.; Geilhufe, J.; Pfau, B; Rander, T.; Schaffert, S.; Büldt, G; Eisebitt, S.

    2012-01-01

    We demonstrate an x-ray imaging method that combines Fourier transform holography with tomography ('tomoholography') for three-dimensional (3D) microscopic imaging. A 3D image of a diatom shell with a spatial resolution of 140 nm is presented. The experiment is realized by using a small gold sphere as the reference wave source for holographic imaging. This setup allows us to rotate the sample and to collect a number of 2D projections for tomography.

  13. X-ray tube arrangements

    International Nuclear Information System (INIS)

    A technique for ensuring the rapid correction of both amplitude and offset errors in the deflectional movement of an electron beam along an X-ray emissive target is described. The movement is monitored at at least two positions during a sweep and differences, between the two movements and a desired movement, at these positions are combined in different proportions to produce a corrective servo signal. Such arrangements find application, for example, in computerised tomographic scanners. (author)

  14. X-Ray Crystallography Reagent

    Science.gov (United States)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2003-01-01

    Microcapsules prepared by encapsulating an aqueous solution of a protein, drug or other bioactive substance inside a semi-permeable membrane by are disclosed. The microcapsules are formed by interfacial coacervation under conditions where the shear forces are limited to 0-100 dynes per square centimeter at the interface. By placing the microcapsules in a high osmotic dewatering solution. the protein solution is gradually made saturated and then supersaturated. and the controlled nucleation and crystallization of the protein is achieved. The crystal-filled microcapsules prepared by this method can be conveniently harvested and stored while keeping the encapsulated crystals in essentially pristine condition due to the rugged. protective membrane. Because the membrane components themselves are x-ray transparent, large crystal-containing microcapsules can be individually selected, mounted in x-ray capillary tubes and subjected to high energy x-ray diffraction studies to determine the 3-D smucture of the protein molecules. Certain embodiments of the microcapsules of the invention have composite polymeric outer membranes which are somewhat elastic, water insoluble, permeable only to water, salts, and low molecular weight molecules and are structurally stable in fluid shear forces typically encountered in the human vascular system.

  15. X-ray-powered macronovae

    CERN Document Server

    Kisaka, Shota; Nakar, Ehud

    2015-01-01

    A macronova (or kilonova) was observed as an infrared excess several days after short gamma-ray burst, GRB 130603B. Although the $r$-process radioactivity is widely discussed as an energy source, it requires huge mass of ejecta from a neutron star (NS) binary merger. We propose that the X-ray excess simultaneously observed with the infrared excess can naturally heat the ejecta, leading to the thermal re-emission as observed in infrared. This X-ray-powered model explains both the X-ray and infrared excesses with a single energy source by the central engine like a black hole, and allows for broader parameter region, in particular smaller ejecta mass $\\sim10^{-3}-10^{-2}M_{\\odot}$ with iron mixed as suggested by general relativistic simulations for typical NS-NS mergers, than the previous models. We also discuss the other macronova candidates in GRB 060614 and GRB 080503, and implications for the search of electromagnetic counterparts to gravitational waves.

  16. X-Ray-powered Macronovae

    Science.gov (United States)

    Kisaka, Shota; Ioka, Kunihito; Nakar, Ehud

    2016-02-01

    A macronova (or kilonova) was observed as an infrared excess several days after the short gamma-ray burst GRB 130603B. Although the r-process radioactivity is widely discussed as an energy source, it requires a huge mass of ejecta from a neutron star (NS) binary merger. We propose a new model in which the X-ray excess gives rise to the simultaneously observed infrared excess via thermal re-emission, and explore what constraints this would place on the mass and velocity of the ejecta. This X-ray-powered model explains both the X-ray and infrared excesses with a single energy source such as the central engine like a black hole, and allows for a broader parameter region than the previous models, in particular a smaller ejecta mass ˜ {10}-3{--}{10}-2{M}⊙ and higher iron abundance mixed as suggested by general relativistic simulations for typical NS-NS mergers. We also discuss the other macronova candidates in GRB 060614 and GRB 080503, and the implications for the search of electromagnetic counterparts to gravitational waves.

  17. To Investigate the Clinical Diagnostic Value of X-ray Barium Contrast Fine Gas Stomach for Gastric Cancer%探讨X线胃精细钡气造影对胃癌的临床诊断价值

    Institute of Scientific and Technical Information of China (English)

    孙连明

    2015-01-01

    目的:探讨X线胃精细钡气造影对胃癌的临床诊断价值。方法本文选取我院于2013年8月~2014年8月收治的58例胃癌患者,对其实施X线胃精细钡气造影检测过程,同时结合患者的临床症状表现和病理检测结果进行对比研究和探讨。结果58例胃癌患者,经过实施X线胃精细钡气造影检测过程后,其中有51例患者诊断疑似为胃癌患者,其中40例患者是溃疡型胃癌患者,7例患者是蕈伞型胃癌患者,剩下的4例患者是肿块型胃癌患者。有4例患者被诊断为糜烂性胃炎,有3例患者出现了漏诊,实施X线胃精细钡气造影检测的诊断率为87.93%。结论胃癌患者采用X 线胃精细钡气造影检测方式,能够有效的提高胃癌患者的临床诊断准确率,同时也可以结合临床病理结果及时的开展治疗过程,提高胃癌患者的医治疗效。%Objective To study the X-ray stomach fine barium contrast the clinical diagnostic value of stomach cancer.MethodsThis article selects in August 2013 to August 2014, 58 patients with gastric cancer, the fine imposed X-ray gastric barium gas imaging detection process, and combining with the patient's clinical symptoms and pathological detection result contrast research and discussion.Results58 patients with gastric cancer, after the implementation of fine barium X-ray stomach gas after angiography examination process, including 51 patients were diagnosed suspected as gastric cancer patients, among them 40 patients is ulcer in patients with gastric cancer, 7 cases of patients is mushroom umbrella gastric cancer patients, the remaining four patients is mass in patients with gastric cancer. With 4 patients were diagnosed with erosive gastritis, there are 3 patients appeared in diagnosis, implementation of X-ray stomach ifne barium imaging detection detection rate of 87.93%.ConclusionPatients with gastric cancer using X-ray stomach gas ifne barium imaging detection

  18. Evaluation of conventional x-ray diagnostic equipment and radiological protection systems of hospitals and clinics installed in Recife city, Brazil

    International Nuclear Information System (INIS)

    Diagnostic radiology is the main contributor to the man-made exposure of general population. Since Quality Assurance (QA) programs ensure high quality diagnostic images with the lowest possible radiation dose to the patient, it has been recommended that all introduce QA programs for their radiological facilities. Consequently it is important to check the adequacy of equipment operating parameters in diagnostic radiography facilities, to ensure that a high quality of service is delivered. The purpose of this study was to evaluate the operating conditions of diagnostic units installed in Recife, Pernambuco. The study included 31 X-ray units from both public and private diagnostic services. The following parameters were evaluated: coincidence between the luminous and radiation fields; alignment of the radiation beam; agreement between the real and preset values of kVp and exposure time; filtration; half value lower (HVL); luminance of the view box; uniformity of the luminance; illuminance of the environment. The results showed that 20% of the equipment surveyed exhibited discrepancies between the luminous and radiation fields greater than 2% of the source to skin distance. The test of kilovoltage showed that 48% of the units do not fulfill the acceptability criteria, presenting discrepancies higher than ± 10% between the measured and preset values. The results of the accuracy of the timer indicated that 81% of the equipment surveyed present a discrepancy greater than 10% between the time selected in the control panel and actual exposure time.The test of the filtration shown that, in 20% of the equipment, this was inferior to 2,5 mm Al. The test of the luminance of view box shown that 96% of the equipment, shown a luminance lower of 2.000 cd/m2. Related to the test of the uniformity of the luminance, 81 % of the equipment shown a variation of the uniformity higher then 10%. The test of the iluminancy of the environment shown that 61 % of the equipment presented on

  19. Dose optimization in cardiac x-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gislason-Lee, Amber J.; McMillan, Catherine; Cowen, Arnold R.; Davies, Andrew G. [LXi Research, Division of Medical Physics, University of Leeds, Worsley Building, Clarendon Way, Leeds LS2 9JT (United Kingdom)

    2013-09-15

    Purpose: The aim of this research was to optimize x-ray image quality to dose ratios in the cardiac catheterization laboratory. This study examined independently the effects of peak x-ray tube voltage (kVp), copper (Cu), and gadolinium (Gd) x-ray beam filtration on the image quality to radiation dose balance for adult patient sizes.Methods: Image sequences of polymethyl methacrylate (PMMA) phantoms representing two adult patient sizes were captured using a modern flat panel detector based x-ray imaging system. Tin and copper test details were used to simulate iodine-based contrast medium and stents/guide wires respectively, which are used in clinical procedures. Noise measurement for a flat field image and test detail contrast were used to calculate the contrast to noise ratio (CNR). Entrance surface dose (ESD) and effective dose measurements were obtained to calculate the figure of merit (FOM), CNR{sup 2}/dose. This FOM determined the dose efficiency of x-ray spectra investigated. Images were captured with 0.0, 0.1, 0.25, 0.4, and 0.9 mm Cu filtration and with a range of gadolinium oxysulphide (Gd{sub 2}O{sub 2}S) filtration.Results: Optimum x-ray spectra were the same for the tin and copper test details. Lower peak tube voltages were generally favored. For the 20 cm phantom, using 2 Lanex Fast Back Gd{sub 2}O{sub 2}S screens as x-ray filtration at 65 kVp provided the highest FOM considering ESD and effective dose. Considering ESD, this FOM was only marginally larger than that from using 0.4 mm Cu at 65 kVp. For the 30 cm phantom, using 0.25 mm copper filtration at 80 kVp was most optimal; considering effective dose the FOM was highest with no filtration at 65 kVp.Conclusions: These settings, adjusted for x-ray tube loading limits and clinically acceptable image quality, should provide a useful option for optimizing patient dose to image quality in cardiac x-ray imaging. The same optimal x-ray beam spectra were found for both the tin and copper details, suggesting

  20. 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 ...

  1. Stabilized x-ray generator power supply

    International Nuclear Information System (INIS)

    X-ray diffraction and X-ray fluorescence analysis are very much adopted in laboratories to determine the type and structure of the constituent compounds in solid materials, chemical composition of materials, stress developed on metals etc. These experiments need X-ray beam of fixed intensity and wave length. This can only be achieved by X-ray generator having highly stabilized tube voltage and tube current. This paper describes how X-ray tube high voltage and electron beam current are stabilized. This paper also highlights generation of X-rays, diffractometry and X-ray fluorescence analysis and their wide applications. Principle of operation for stabilizing the X-ray tube voltage and current, different protection circuits adopted, special features of the mains H.V. transformer and H.T. tank are described in this report. (author)

  2. The Clinical and Radiologic Presentation of X-ray on Unstable Cervical Vertebra Disease%颈椎不稳症的X线临床与影像表现

    Institute of Scientific and Technical Information of China (English)

    刘维久; 艾阳平; 付建华

    2012-01-01

    目的:通过X线探讨和分析颈椎不稳的临床与影像表现.方法:对我院的100例诊断为颈椎不稳症的患者实施X线拍片,拍颈椎正侧位片、双斜位片及侧位过伸过曲片.结果:100例颈椎不稳患者的X线表现结果:上颈椎不稳有32例,占32%,其中环枕不稳定的例数有4例,有3例为外伤引起,1例为先天畸形;环枢椎不稳定的有28例,有2例为发育畸形,炎症导致不稳定的有4例,手术原因引起的有2例,退行性病变引起的有20例;下颈椎不稳症的例数有68例,占68.00%,其中外伤引起的有45例,退行性病10例,手术原因引起的有4例,炎症导致的有1例,先天性发育异常有8例.颈椎不稳定病变主要发生在下颈椎,从X线片可知,下颈椎的C3、C4、C5 发生不稳定症的机会大,它们向前的位移均超过2mm.结论:通过颈椎X线分析发现颈椎不稳定症主要发生在下颈椎,并且主要发生在C3、C4、C5.%Objective: To analyse the clinical and radiologic presentation of X-ray on unstable cervical vertebra disease through X-ray. Method: Chose 100 diagnosed unstable cervical vertebra disease patients in our hospital with X-ray inspection, took anterio posterio rand lateral film, Double inclined a piece of and ide had a reach of bowed. Result: 100 patients with unstable cervical X - ray performance. The upper cervical spine instability was 32 cases, accounting for 32% , among which ring pillow unstable number was 4 cases, 3 cases were caused by traumatic injury and 1 case was congenital malformation; Ring of vertebral instability of coffins was 28 cases, there were 2 cases of malformations, inflammation in the stable was 4 cases, 2 cases was causedby surgery, 20 cases were caused by degenerative diseases; The cervical vertebra disease instability out was 68 cases, accounting for 68. 00% , with traumatic cause was 45 cases, retreat a venereal was 10 cases, the cause of surgery was 4 cases, inflammation of the lead to one example

  3. Analysis on Clinical Application and Protective Efficacies of New Stand for Field Portable X-ray Apparatus%新型便携式野战X线机支架临床应用及防护效果分析

    Institute of Scientific and Technical Information of China (English)

    刘志洲; 王奕菲; 富凯; 敖宁; 徐颖

    2013-01-01

    目的:评价新型便携式野战X线机支架的临床应用及防护效果.方法:模拟野战条件下担架搬运伤痛员232例,身高165~170 cm,体质量60~65 kg,把伤病员按摄影体位分为7组,分别进行胸部、肱骨、尺桡骨、手、股骨、胫腓骨、足进行摄片,每组采用相同的条件曝光,测量支架内外X线剂量及评价X线片拍摄质量.结果:采用新型便携式野战X线机支架后,各组支架内外X线剂量(mGy/h)分别为胸部(102.2、3.1)、肱骨(24.1、0.5)、尺桡骨(25.1、0.5)、手(10.6、0.2)、股骨(41.3、1.0)、胫腓骨(39.8、0.9)、足(29.8、0.5),支架外比支架内各组总平均X线照射量率降低97.5%;X线片质量优秀223例,占总数96.1%,无不合格X线片.结论:使用新型野战便携式X线机支架可显著提高X线片拍摄质量,减少医疗工作者和伤病员不必要的X线辐射,从而提高卫勤保障能力.%Objective To evaluate the clinical application and protective efficacies of a new stand for the field portable X-ray apparatus. Methods There were 232 stretcher patients simulated in the field condition, with the heights between 165 cm and 170 cm and the weights between 60 kg and 65 kg, who were divided into seven groups according to the photography postures including the chest, humerus, ulna and radius, hand, femoral bone, tibiofibula and foot. With the same exposure factors, the X-ray doses in and out of the stand as well as the X-ray photography qualities were measured. Results With regard to the X-ray doses in and out of the stand, the values were 102.2 and 3.1 for the chest, 24.1 and 0.5 for the humerus, 25.1 and 0.5 for the ulna and radius, 10.6 and 0.2 for the hand, 41.3 and 1.0 for the femoral bone, 39.8 and 0.9 for the tibiofibula, 29.8 and 0.5 for the foot, respectively. The X-ray doses in the stand were reduced by 97.5% than that out of the stand. There were 223 excellent X-ray films with a ratio of 96.1%, and no unqualified ones. Conclusion

  4. Phase-sensitive X-ray imager

    Science.gov (United States)

    Baker, Kevin Louis

    2013-01-08

    X-ray phase sensitive wave-front sensor techniques are detailed that are capable of measuring the entire two-dimensional x-ray electric field, both the amplitude and phase, with a single measurement. These Hartmann sensing and 2-D Shear interferometry wave-front sensors do not require a temporally coherent source and are therefore compatible with x-ray tubes and also with laser-produced or x-pinch x-ray sources.

  5. Optical element for X-ray microscopy

    OpenAIRE

    Chadzitaskos, G.

    2008-01-01

    We present a proposal for a X-ray optical element suitable for X-ray microscopy and other X-ray-based display systems. Its principle is based on the Fresnel lenses condition and the Bragg condition for X-ray scattering on a slice of monocrystal. These conditions are fulfilled simultaneously due to a properly machined shape of the monocrystal with a stress at its ends.

  6. Cryotomography x-ray microscopy state

    Science.gov (United States)

    Le Gros, Mark; Larabell, Carolyn A.

    2010-10-26

    An x-ray microscope stage enables alignment of a sample about a rotation axis to enable three dimensional tomographic imaging of the sample using an x-ray microscope. A heat exchanger assembly provides cooled gas to a sample during x-ray microscopic imaging.

  7. Center for X-ray Optics, 1988

    International Nuclear Information System (INIS)

    This report briefly reviews the following topics: soft-x-ray imaging; reflective optics for hard x-rays; coherent XUV sources; spectroscopy with x-rays; detectors for coronary artery imaging; synchrotron-radiation optics; and support for the advanced light source

  8. Electron beam parallel X-ray generator

    Science.gov (United States)

    Payne, P.

    1967-01-01

    Broad X ray source produces a highly collimated beam of low energy X rays - a beam with 2 to 5 arc minutes of divergence at energies between 1 and 6 keV in less than 5 feet. The X ray beam is generated by electron bombardment of a target from a large area electron gun.

  9. X-Ray Exam: Neck (For Parents)

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Neck KidsHealth > For Parents > X-Ray Exam: Neck Print A A A Text Size ... español Radiografía: cuello What It Is A neck X-ray is a safe and painless test that uses ...

  10. X-ray tracing using Geant4

    International Nuclear Information System (INIS)

    We describe an extension to the Geant4 software package that allows it to be used as a general purpose X-ray tracing package. We demonstrate the use of our extension by building a model of the X-ray optics of the X-ray observatory XMM-Newton, calculating its effective area, and comparing the results with the published calibration curves.

  11. Chest X-ray imaging of patients with SARS

    Institute of Scientific and Technical Information of China (English)

    陆普选; 周伯平; 陈心春; 袁明远; 龚小龙; 杨根东; 刘锦清; 袁本通; 郑广平; 杨桂林; 王火生

    2003-01-01

    Objective To investigate the chest X-ray manifestations of SARS cases.Methods A retrospective study was conducted among 52 clinically confirmed SARS patients from February 9 to May 10, 2003. Chest X-ray scanning was performed at a interval of 1-3 days according to the requirements. The manifestations and special features of SARS in X-ray were analyzed. Results Small or large patchy shadows with intensive density in both lungs were observed in 31 cases, ground-glass like opacification in 16, small patchy shadows in one lung lobe or one lung segment in 18, nodular shadows in one lung segment in 1, and increased lung marking in lung interstitial tissues in 2. Rapidly changing consolidations revealed in chest X-ray images were found to be associated with SARS infections, and they were not affected by treatment with antibiotics.Conclusion Chest X-ray provides a sensitive and specific method for the diagnosis and treatment of SARS, and those present with symptoms and signs should undergo chest X-ray scanning every 1-3 days.

  12. Analysis of the Clinical Value of X-ray Diagnosis of Cervical Vertebra Degeneration%X线对青年颈椎退行性变的诊断价值

    Institute of Scientific and Technical Information of China (English)

    李征军; 肖本模

    2015-01-01

    目的:探讨青年颈椎退变的主要影像特征,并对其检查方法、临床特点、发病原因等进行分析。方法本文收集60例30岁以下颈椎退行性变患者资料,分析其X线影像特征及发病原因、临床特点等,并对相关分析进行总结。结果青年颈椎退变的临床特点主要有颈项强直、活动受限,肩痛不适,部分伴有头晕及上肢麻木等。其主要X线特征为颈椎生理曲度改变、颈椎椎体增生及椎间隙变窄等,发病因素与不良的工作、生活习惯及锻炼不足密切相关。结论 X线多体位摄片应作为青年颈椎退行性变的首选及常规检查方法,其影像特征对临床诊断及防治意义重大。%Objective To explore the main image characteristics of youth cervical vertebra degeneration, and the inspection method, clinical characteristics and causes were analyzed. Methods This paper col ected 60 cases under the age of 30 patients with cervical vertebrae degeneration data, analysis the X-ray features and etiology, clinical characteristics, etc., and to summarize cor elation analysis. Results The clinical characteristics of youth cervical vertebra degeneration is mainly has a neck stif ness, limited activity, shoulder pain, accompanied by dizziness and upper limb numbness, etc. The main X-ray features for cervical physiological curvature change narrow, hyperplasia of cervical vertebral body and intervertebral disc, etc., risk factors and bad work, life habits and lack of exercise are closely related. Conclusion X-ray radiography more position should be as a youth cervical vertebra degeneration of choice and routine inspection method, the image features is of great significance to clinical diagnosis and treatment.

  13. Spherical grating based x-ray Talbot interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Cong, Wenxiang, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu; Xi, Yan, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu; Wang, Ge, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu [Biomedical Imaging Center, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2015-11-15

    Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and

  14. Spherical grating based x-ray Talbot interferometry

    International Nuclear Information System (INIS)

    Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and

  15. Protonium X-ray spectroscopy

    CERN Document Server

    Gotta, D

    1999-01-01

    The Lyman and Balmer transitions from antiprotonic hydrogen and deuterium were studied extensively at the low-energy-antiproton ring LEAR at CERN in order to determine the strong interaction effects. A first series of experiments $9 was performed with semiconductor and gaseous X-ray detectors. In the last years of LEAR operation using a Bragg crystal spectrometer, strong interaction parameters in the 2p states of antiprotonic hydrogen and deuterium were measured $9 directly. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction. (39 refs).

  16. X-ray tomographic apparatus

    International Nuclear Information System (INIS)

    An x-ray tomographic system consists of a radiation source such as gamma or x radiation which produces a fan-shaped beam. The fan is wide enough to encompass the patient circle. The system further includes means for rotating the radiation source about the patient for less than a full rotation, and detectors for detecting the radiation at positions that surround the patient by 1800 plus the angle of the fan beam plus the angle between adjacent fan detectors. Attenuation data from the detectors is sorted into detector fans of attenuation data, then processed. The convolved data is back-projected into an image memory and displayed on a video monitor

  17. X-ray Pulsations in the Supersoft X-ray Binary CAL 83

    OpenAIRE

    Schmidtke, P. C.; Cowley, A. P.

    2005-01-01

    X-ray data reveal that the supersoft X-ray binary CAL 83 exhibits 38.4 minute pulsations at some epochs. These X-ray variations are similar to those found in some novae and are likely to be caused by nonradial pulsations the white dwarf. This is the first detection of pulsations in a classical supersoft X-ray binary.

  18. Ionospheric effects of solar x-rays

    Science.gov (United States)

    Danskin, Donald

    2016-07-01

    The ionospheric absorption of radio waves caused by solar x-ray bursts is measured directly by Riometers from the Canada Riometer Array. The absorption is found to be proportional to the square root of the flux intensity of the X-ray burst with time delays of 18-20 seconds between the peak X-ray emission and absorption in the ionosphere. A detailed analysis showed that some X-ray flares during 2011-2014 are more effective at producing absorption than others. Solar longitude of X-ray burst for several X-class flares shows no consistent pattern of enhancement in the absorption.

  19. Comets: mechanisms of x-ray activity

    Science.gov (United States)

    Ibadov, Subhon

    2016-07-01

    Basic mechanisms of X-ray activity of comets are considered, including D-D mechanism corresponding to generation of X-rays due to production of hot short-living plasma clumps at high-velocity collisions between cometary and interplanetary dust particles as well as M-M one corresponding to production of X-rays due to recombination of multicharge ions of solar wind plasma via charge exchange process at their collisions with molecules/atoms of the cometary atmospheres. Peculiarities of the variation of the comet X-ray spectrum and X-ray luminosity with variation of its heliocentric distance are revealed.

  20. Swift Observations of X-ray supernovae

    OpenAIRE

    Li, K. L.; Pun, Chun. S. J.

    2011-01-01

    We present a result of X-ray supernovae (SNe) survey using the Swift satellite public archive. An automatic searching program was designed to search X-ray SNe among all of the Swift archival observations between November 2004 and February 2011. Using the C++ program, 24 X-ray detectable supernovae have been found in the archive and 3 of them were newly-discovered in X-rays which are SN 1986L, SN 2003lx, and SN 2007od. In addition, SN 2003lx is a Type Ia supernova which may be the second X-ray...

  1. Symbiotic stars in X-rays

    OpenAIRE

    Luna, G. J. M.; Sokoloski, J. L.; Mukai, K; Nelson, T.

    2012-01-01

    Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of nine white dwarf symbiotics that were not previously known to be X-ray sources and one that had previously been detected as a supersoft X-ray source. The nine new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbi...

  2. Correlation of X-Ray Computed Tomography with Quantitative Nuclear Magnetic Resonance Methods for Pre-Clinical Measurement of Adipose and Lean Tissues in Living Mice

    Directory of Open Access Journals (Sweden)

    Matthew N. Metzinger

    2014-10-01

    Full Text Available Numerous obesity studies have coupled murine models with non-invasive methods to quantify body composition in longitudinal experiments, including X-ray computed tomography (CT or quantitative nuclear magnetic resonance (QMR. Both microCT and QMR have been separately validated with invasive techniques of adipose tissue quantification, like post-mortem fat extraction and measurement. Here we report a head-to-head study of both protocols using oil phantoms and mouse populations to determine the parameters that best align CT data with that from QMR. First, an in vitro analysis of oil/water mixtures was used to calibrate and assess the overall accuracy of microCT vs. QMR data. Next, experiments were conducted with two cohorts of living mice (either homogenous or heterogeneous by sex, age and genetic backgrounds to assess the microCT imaging technique for adipose tissue segmentation and quantification relative to QMR. Adipose mass values were obtained from microCT data with three different resolutions, after which the data were analyzed with different filter and segmentation settings. Strong linearity was noted between the adipose mass values obtained with microCT and QMR, with optimal parameters and scan conditions reported herein. Lean tissue (muscle, internal organs was also segmented and quantified using the microCT method relative to the analogous QMR values. Overall, the rigorous calibration and validation of the microCT method for murine body composition, relative to QMR, ensures its validity for segmentation, quantification and visualization of both adipose and lean tissues.

  3. Fourier transform based iterative method for x-ray differential phase-contrast computed tomography

    OpenAIRE

    Cong, Wenxiang; Momose, Atsushi; Wang, Ge

    2011-01-01

    Biological soft tissues encountered in clinical and pre-clinical imaging mainly consist of light element atoms, and their composition is nearly uniform with little density variation. Thus, x-ray attenuation imaging suffers from low image contrast resolution. By contrast, x-ray phase shift of soft tissues is about a thousand times greater than x-ray absorption over the diagnostic energy range, thereby a significantly higher sensitivity can be achieved in terms of phase shift. In this paper, we...

  4. Long bone X-ray image stitching using Camera Augmented Mobile C-arm.

    Science.gov (United States)

    Wang, Lejing; Traub, Joerg; Heining, Sandro Michael; Benhimane, Selim; Euler, Ekkehard; Graumann, Rainer; Navab, Nassir

    2008-01-01

    X-ray images are widely used during surgery for long bone fracture fixation. Mobile C-arms provide X-ray images which are used to determine the quality of trauma reduction, i.e. the extremity length and mechanical axis of long bones. Standard X-ray images have a narrow field of view and can not visualize the entire long bone on a single image. In this paper, we propose a novel method to generate panoramic X-ray images in real time by using the previously introduced Camera Augmented Mobile C-arm. This advanced mobile C-arm system acquires registered X-ray and optical images by construction, which facilitates the generation of panoramic X-ray images based on first stitching the optical images and then embedding the X-ray images. We additionally introduce a method to reduce the parallax effect that leads to the blurring and measurement error on panoramic X-ray images. Visual marker tracking is employed to automatically stitch the sequence of video images and to rectify images. Our proposed method is suitable for intra-operative usage generating panoramic X-ray images, which enable metric measurements, with less radiation and without requirement of fronto-parallel setup and overlapping X-ray images. The results show that the panoramic X-ray images generated by our method are accurate enough (errors less than 1%) for metric measurements and suitable for many clinical applications in trauma reduction.

  5. Full-field transmission x-ray imaging with confocal polycapillary x-ray optics

    OpenAIRE

    Sun, Tianxi; MacDonald, C. A.

    2013-01-01

    A transmission x-ray imaging setup based on a confocal combination of a polycapillary focusing x-ray optic followed by a polycapillary collimating x-ray optic was designed and demonstrated to have good resolution, better than the unmagnified pixel size and unlimited by the x-ray tube spot size. This imaging setup has potential application in x-ray imaging for small samples, for example, for histology specimens.

  6. Direct X-ray radiogrammetry versus dual-energy X-ray absorptiometry: assessment of bone density in children treated for acute lymphoblastic leukaemia and growth hormone deficiency

    NARCIS (Netherlands)

    R.R. van Rijn; A. Boot; R. Wittenberg; I.M. van der Sluis; M.M. van den Heuvel-Eibrink; M.H. Lequin; S.M.P.F. de Muinckkeizer-Schrama; C. van Kuijk

    2006-01-01

    Background: In recent years interest in bone densitometry in children has increased. Objective: To evaluate the clinical application of digital X-ray radiogrammetry (DXR) and compare the results with those of dual-energy X-ray absorptiometry (DXA). Materials and methods: A total of 41 children with

  7. 胸片和临床症状肺结核筛查的应用价值%Application Value of Chest X-Ray and Clinical Symptoms of Pulmonary Tuberculosis Screening

    Institute of Scientific and Technical Information of China (English)

    张延安

    2014-01-01

    Objective: To evaluate the value of clinical application of chest X-ray and clinical symptoms of pulmonary TB screening. Methods:All objects by symptoms, chest X-ray screening questionnaire (CXR), and (or) sputum smear or culture. Results:There were abnormal CXR sensitivity was 94%, specificity was 73%. The sensitivity of screening with symptoms was 90%, the specificity was 32%. Smear microscopy failed to increase the suspicious patients, joint symptoms and CXR screening sensitivity was 100%, specificity was 65%. Conclusion:Only by CXR screening showed that the accuracy of screening compared with symptoms of high, combined with CXR and symptom screening has the highest sensitivity.%目的:评估胸片和临床症状对肺TB筛查的应用价值。方法:所有对象经症状问卷筛查、胸片(CXR)、和(或)痰涂片或培养。结果:存在CXR异常者敏感性为94%,特异性为73%。症状筛查结合的敏感性为90%,特异性为32%。涂片显微镜检查未能增加可疑病人,联合症状和CXR筛查敏感性达100%,特异性达65%。结论:仅用CXR筛查即呈现较单纯症状筛查高的准确度,联合CXR和症状筛查有最高的敏感性。

  8. X-Ray Attenuation Cell

    Energy Technology Data Exchange (ETDEWEB)

    Ryutov, D.; Toor, A.

    2000-03-03

    To minimize the pulse-to-pulse variation, the LCLS FEL must operate at saturation, i.e. 10 orders of magnitude brighter spectral brilliance than 3rd-generation light sources. At this intensity, ultra-high vacuums and windowless transport are required. Many of the experiments, however, will need to be conducted at a much lower intensity thereby requiring a reliable means to reduce the x-ray intensity by many orders of magnitude without increasing the pulse-to-pulse variation. In this report we consider a possible solution for controlled attenuation of the LCLS x-ray radiation. We suggest using for this purpose a windowless gas-filled cell with the differential pumping. Although this scheme is easily realizable in principle, it has to be demonstrated that the attenuator can be made short enough to be practical and that the gas loads delivered to the vacuum line of sight (LOS) are acceptable. We are not going to present a final, optimized design. Instead, we will provide a preliminary analysis showing that the whole concept is robust and is worth further study. The spatial structure of the LCLS x-ray pulse at the location of the attenuator is shown in Fig. 1. The central high-intensity component, due to the FEL, has a FWHM of {approx}100 {micro}m. A second component, due to the undulator's broad band spontaneous radiation is seen as a much lower intensity ''halo'' with a FWHM of 1 mm. We discuss two versions of the attenuation cell. The first is directed towards a controlled attenuation of the FEL up to the 4 orders of magnitude in the intensity, with the spontaneous radiation halo being eliminated by collimators. In the second version, the spontaneous radiation is not sacrificed but the FEL component (as well as the first harmonic of the spontaneous radiation) gets attenuated by a more modest factor up to 100. We will make all the estimates assuming that the gas used in the attenuator is Xenon and that the energy of the FEL is 8.25 keV. At

  9. Medical CT image reconstruction accuracy in the presence of metal objects using x-rays up to 1 MeV with x-ray targets of beryllium, carbon, aluminum, copper, and tungsten

    Science.gov (United States)

    Clayton, James; Ganguly, Arundhuti; Virshup, Gary

    2012-04-01

    Flat panels imagers based on amorphous silicon technology (a-Si) for digital radiography have been accepted by the medical community as having several advantages over film-based systems. Radiotherapy treatment planning systems employ computed tomographic (CT) data sets and projection images to delineate tumor targets and normal structures that are to be spared from radiation treatment. The accuracy of CT numbers is crucial for radiotherapy dose calculations. Conventional CT scanners operating at kilovoltage X-ray energies typically exhibit significant image reconstruction artifacts in the presence of metal implants in human body. Megavoltage X-ray energies have problems maintaining contrast sensitivity for the same dose as kV X-ray systems. We intend to demonstrate significant improvement in metal artifact reductions and electron density measurements using an amorphous silicon a-Si imager obtained with an X-ray source that can operate at energies up to 1 MeV. We will investigate the ability to maintain contrast sensitivity at this higher X-ray energy by using targets with lower atomic numbers and appropriate amounts of Xray filtration than are typically used as X-ray production targets and filters.

  10. X-ray intensifying screens

    International Nuclear Information System (INIS)

    An x-ray intensifying screen comprises a support which has a luminescent composition comprising an isotropic phosphor and a polymer having an index of refraction within 0.02 of that of the phosphor over at least 80 percent of its emission spectrum. The support has an index of refraction up to or equal to 0.05 units higher than that of the phosphor and has a reflection optical density of at least 1.7 to light emitted by the phosphor. A preferred luminescent composition comprises Kl:Tl, Rbl:Tl at BaSrFCl:Eu mixed with two monomers such as 1-naphthylmethylmethacrylate, S(1-naphthylmethyl) thioacrylate, 1-bromo-2-naphthylacrylate, and benzyl methacrylate, coated on black anodised Al and polymerised in situ. The ratio of monomers is adjusted to give the desired refractive index. Other phosphors, polymers and supports are specified together with the preparation of the monomers and polymers. (author)

  11. X-ray flat panel detectors and X-ray tubes contributing to development of X-ray diagnostic systems

    International Nuclear Information System (INIS)

    X-ray flat panel detectors (FPDs) and X-ray tubes are key devices allowing X-ray diagnostic systems to support more sophisticated medical care. FPDs provide valuable information for the diagnosis of various diseases through the conversion of X-ray images of the human body into electronic signals, while X-ray tubes are used in a wide range of applications such as computed tomography (CT), angiography, fluoroscopy, mammography, and dental systems. Toshiba Electron Tubes and Devices Co., Ltd. has developed and commercialized FPDs providing high-quality diagnostic X-ray images with low dose exposure through the development of cutting-edge technologies including a fine crystal formation technology for cesium iodide (CsI) scintillators, thin-film transistor (TFT) arrays with photodiodes, and so on. In the field of X-ray tubes that can generate a high output of X-rays, we have developed a liquid metal hydrodynamic bearing (LM bearing) technology for various diagnostic systems including medical CT systems with a long lifetime and high rotation speed, and cardiovascular imaging systems with quiet operation. Furthermore, LM bearing technology reduces the burden on the environment by replacing insulating oil with water coolant for the cooling system and making the X-ray tubes more compact. (author)

  12. Soft x-ray interferometry

    International Nuclear Information System (INIS)

    The purpose of the soft x-ray interferometry workshop held at Lawrence Berkeley Laboratory was to discuss with the scientific community the proposed technical design of the soft x-ray Fourier-transform spectrometer being developed at the ALS. Different design strategies for the instrument's components were discussed, as well as detection methods, signal processing issues, and how to meet the manufacturing tolerances that are necessary for the instrument to achieve the desired levels of performance. Workshop participants were encouraged to report on their experiences in the field of Fourier transform spectroscopy. The ALS is developing a Fourier transform spectrometer that is intended to operate up to 100 eV. The motivation is solely improved resolution and not the throughput (Jaquinot) or multiplex (Fellgett) advantage, neither of which apply for the sources and detectors used in this spectral range. The proposed implementation of this is via a Mach-Zehnder geometry that has been (1) distorted from a square to a rhombus to get grazing incidence of a suitable angle for 100 eV and (2) provided with a mirror-motion system to make the path difference between the interfering beams tunable. The experiment consists of measuring the emergent light intensity (I(x)) as a function of the path difference (x). The resolving power of the system is limited by the amount of path difference obtainable that is 1 cm (one million half-waves at 200 angstrom wavelength) in the design thus allowing a resolving power of one million. The free spectral range of the system is limited by the closeness with which the function I(x) is sampled. It is proposed to illuminate a helium absorption cell with roughly 1%-band-width light from a monochromator thus allowing one hundred aliases without spectral overlap even for sampling of I(x) at one hundredth of the Nyquist frequency

  13. Soft x-ray polarimeter laboratory tests

    Science.gov (United States)

    Murphy, Kendrah D.; Marshall, Herman L.; Schulz, Norbert S.; Jenks, Kevin; Sommer, Sophie J. B.; Marshall, Eric A.

    2010-07-01

    Multilayer-coated optics can strongly polarize X-rays and are central to a new design of a broad-band, soft X-ray polarimeter. We have begun laboratory work to verify the performance of components that could be used in future soft X-ray polarimetric instrumentation. We have reconfigured a 17 meter beamline facility, originally developed for testing transmission gratings for Chandra, to include a polarized X-ray source, an X-ray-dispersing transmission grating, and a multilayer-coated optic that illuminates a CCD detector. The X-rays produced from a Manson Model 5, multi-anode source are polarized by a multilayer-coated flat mirror. The current configuration allows for a 180 degree rotation of the source in order to rotate the direction of polarization. We will present progress in source characterization and system modulation measurements as well as null and robustness tests.

  14. X-rays for medical use

    Science.gov (United States)

    Hessenbruch, A.

    1995-11-01

    1995 is the centenary of the discovery of X-rays by the German physicist Wilhelm C Rontgen. In the past hundred years, the new rays have developed from being unknown to finding application in many walks of life, not least in medicine. This is so much so that in common speech the word `x-ray` refers not to a form of radiation but to an X-ray photograph taken for the purposes of diagnosis (as in: `I had an X-ray done to see if my leg was broken`). X-rays are now used routinely, and they are used both for diagnosis and for therapy. This paper will give an outline of the use of X-rays in medicine throughout our present century.

  15. Handbook of X-Ray Data

    CERN Document Server

    Zschornack, Günter

    2007-01-01

    This sourcebook is intended as an X-ray data reference for scientists and engineers working in the field of energy or wavelength dispersive X-ray spectrometry and related fields of basic and applied research, technology, or process and quality controlling. In a concise and informative manner, the most important data connected with the emission of characteristic X-ray lines are tabulated for all elements up to Z = 95 (Americium). This includes X-ray energies, emission rates and widths as well as level characteristics such as binding energies, fluorescence yields, level widths and absorption edges. The tabulated data are characterized and, in most cases, evaluated. Furthermore, all important processes and phenomena connected with the production, emission and detection of characteristic X-rays are discussed. This reference book addresses all researchers and practitioners working with X-ray radiation and fills a gap in the available literature.

  16. In-Line Phase-Contrast Imaging Using Partially Coherent Hard X-Ray

    Institute of Scientific and Technical Information of China (English)

    喻虹; 朱频频; 韩申生; 罗震林; 高琛

    2003-01-01

    An experimental study of in-line hard x-ray phase-contrast imaging had been performed, using the polychromatic output of an x-ray tube. The results are in good agreement with partially coherent theory of hard x-ray phasecontrast imaging. The new technique provides the advantage to obtain the radiographs of large samples in an acceptable exposure time, which is very important to clinical applications.

  17. X-ray microlaminography with polycapillary optics

    Energy Technology Data Exchange (ETDEWEB)

    Dabrowski, K. M.; Dul, D. T.; Wrobel, A.; Korecki, P. [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland)

    2013-06-03

    We demonstrate layer-by-layer x-ray microimaging using polycapillary optics. The depth resolution is achieved without sample or source rotation and in a way similar to classical tomography or laminography. The method takes advantage from large angular apertures of polycapillary optics and from their specific microstructure, which is treated as a coded aperture. The imaging geometry is compatible with polychromatic x-ray sources and with scanning and confocal x-ray fluorescence setups.

  18. X-ray data booklet. Revision

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, D. (ed.)

    1986-04-01

    A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities. (WRF)

  19. Applications of soft x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, C.H.

    1993-08-01

    The high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. Imaging of biological specimens using x-ray lasers has been demonstrated by several groups. Other applications to fields such as chemistry, material science, plasma diagnostics, and lithography are beginning to emerge. We review the current status of soft x-ray lasers from the perspective of applications, and present an overview of the applications currently being developed.

  20. X-ray spot film device

    International Nuclear Information System (INIS)

    Improvements are described in an X-ray spot film device which is used in conjunction with an X-ray table to make a selected number of radiographic exposures on a single film and to perform fluoroscopic examinations. To date, the spot film devices consist of two X-ray field defining masks, one of which is moved manually. The present device is more convenient to use and speeds up the procedure. (U.K.)

  1. X-ray data booklet. Revision

    International Nuclear Information System (INIS)

    A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities

  2. Topological X-Rays and MRIs

    Science.gov (United States)

    Lynch, Mark

    2002-01-01

    Let K be a compact subset of the interior of the unit disk D in the plane and suppose one can't see through the boundary of D and identify K. However, assume that one can take "topological X-rays" of D which measure the "density" of K along the lines of the X-rays. By taking these X-rays from all directions, a "topological MRI" is generated for…

  3. Observation of femtosecond X-ray interactions with matter using an X-ray-X-ray pump-probe scheme.

    Science.gov (United States)

    Inoue, Ichiro; Inubushi, Yuichi; Sato, Takahiro; Tono, Kensuke; Katayama, Tetsuo; Kameshima, Takashi; Ogawa, Kanade; Togashi, Tadashi; Owada, Shigeki; Amemiya, Yoshiyuki; Tanaka, Takashi; Hara, Toru; Yabashi, Makina

    2016-02-01

    Resolution in the X-ray structure determination of noncrystalline samples has been limited to several tens of nanometers, because deep X-ray irradiation required for enhanced resolution causes radiation damage to samples. However, theoretical studies predict that the femtosecond (fs) durations of X-ray free-electron laser (XFEL) pulses make it possible to record scattering signals before the initiation of X-ray damage processes; thus, an ultraintense X-ray beam can be used beyond the conventional limit of radiation dose. Here, we verify this scenario by directly observing femtosecond X-ray damage processes in diamond irradiated with extraordinarily intense (∼10(19) W/cm(2)) XFEL pulses. An X-ray pump-probe diffraction scheme was developed in this study; tightly focused double-5-fs XFEL pulses with time separations ranging from sub-fs to 80 fs were used to excite (i.e., pump) the diamond and characterize (i.e., probe) the temporal changes of the crystalline structures through Bragg reflection. It was found that the pump and probe diffraction intensities remain almost constant for shorter time separations of the double pulse, whereas the probe diffraction intensities decreased after 20 fs following pump pulse irradiation due to the X-ray-induced atomic displacement. This result indicates that sub-10-fs XFEL pulses enable conductions of damageless structural determinations and supports the validity of the theoretical predictions of ultraintense X-ray-matter interactions. The X-ray pump-probe scheme demonstrated here would be effective for understanding ultraintense X-ray-matter interactions, which will greatly stimulate advanced XFEL applications, such as atomic structure determination of a single molecule and generation of exotic matters with high energy densities.

  4. Phase-contrast imaging using polychromatic hard X-rays

    International Nuclear Information System (INIS)

    In conventional radiography, X-rays which pass through an object along different paths are differentially absorbed, and the intensity pattern of the emerging beam records the distribution of absorbing materials within the sample. An alternative approach is phase-contrast radiography, which instead records variations of the phase of the emerging radiation. Such an approach offers improved contrast sensitivity, especially when imaging weakly absorbing samples. Unfortunately, current phase-contrast imaging techniques generally require highly monochromatic plane-wave radiation and sophisticated X-ray optics, so their use is greatly restricted. Here we describe and demonstrate a simplified scheme for phase-contrast imaging based on an X-ray source having high spatial (but essentially no chromatic) coherence. The method is compatible with conventional polychromatic micro-focus X-ray tube sources, is well suited to large areas of irradiation, can operate with a lower absorbed dose than traditional X-ray imaging techniques, and should find broad application in clinical, biological and industrial settings. (Author)

  5. Advances in kilovoltage x-ray beam dosimetry

    Science.gov (United States)

    Hill, Robin; Healy, Brendan; Holloway, Lois; Kuncic, Zdenka; Thwaites, David; Baldock, Clive

    2014-03-01

    This topical review provides an up-to-date overview of the theoretical and practical aspects of therapeutic kilovoltage x-ray beam dosimetry. Kilovoltage x-ray beams have the property that the maximum dose occurs very close to the surface and thus, they are predominantly used in the treatment of skin cancers but also have applications for the treatment of other cancers. In addition, kilovoltage x-ray beams are used in intra operative units, within animal irradiators and in on-board imagers on linear accelerators and kilovoltage dosimetry is important in these applications as well. This review covers both reference and relative dosimetry of kilovoltage x-ray beams and provides recommendations for clinical measurements based on the literature to date. In particular, practical aspects for the selection of dosimeter and phantom material are reviewed to provide suitable advice for medical physicists. An overview is also presented of dosimeters other than ionization chambers which can be used for both relative and in vivo dosimetry. Finally, issues related to the treatment planning and the use of Monte Carlo codes for solving radiation transport problems in kilovoltage x-ray beams are presented.

  6. Advanced X-ray diffractive optics

    OpenAIRE

    Vila-Comamala, J.; Jefimovs, K.; Pilvi, T.; Ritala, M; Sarkar, S S; Solak, H H; Guzenko, V.A.; Stampanoni, M.; Marone, F.; J. Raabe; G. Tzvetkov; Fink, R H; Grolimund, D.; Borca, C.N.; Kaulich, B

    2009-01-01

    X-ray microscopy greatly bene�ts from the advances in x-ray optics. At the Paul Scherrer Institut, developments in x-ray di�ractive optics include the manufacture and optimization of Fresnel zone plates (FZPs) and di�ractive optical elements for both soft and hard x-ray regimes. In particular, we demonstrate here a novel method for the production of ultra-high resolution FZPs. This technique is based on the deposition of a zone plate material (iridium) onto the sidewalls of a p...

  7. Symbiotic Stars in X-rays

    Science.gov (United States)

    Luna, G. J. M.; Sokoloski, J. L.; Mukai, K.; Nelson, T.

    2014-01-01

    Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of 9 white dwarf symbiotics that were not previously known to be X-ray sources and one that was previously detected as a supersoft X-ray source. The 9 new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. Swift/XRT detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component, which we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component, which likely arises in a region where low-velocity shocks produce X-ray emission, i.e. a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the alpha/beta/gamma classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new sigma classification for sources with

  8. The Lunar X-ray Observatory (LXO)

    Science.gov (United States)

    Porter, F. Scott

    2008-01-01

    X-ray emission from charge exchange recombination between the highly ionized solar wind and neutral material i n Earth's magnetosheath has complicated x-ray observations of celestial objects with x-ray observatories including ROSAT, Chandra, XMM-Newton, and Suzaku. However, the charge-exchange emission can also be used as an important diagnostic of the solar-wind interacting with the magnetosheath. Soft x-ray observations from low-earth orbit or even the highly eccentric orbits of Chandra and XMM-Newton are likely superpositions of the celestial object of interest, the true extra-solar soft x-ray background, geospheric charge exchange, and heliospheric charge exchange. We show that with a small x-ray telescope placed either on the moon, in a similar vein as the Apollo ALSOP instruments, or at a stable orbit near L1, we can begin t o disentangle the complicated emission structure in the soft x-ray band. Here we present initial results of a feasibility study recently funded by NASA t o place a small x-ray telescope on the lunar surface. The telescope operates during lunar night to observe charge exchange interactions between the solar wind and magnetospheric neutrals, between the solar wind and the lunar atmosphere, and an unobstructed view of the soft x-ray background without the geospheric component.

  9. Ultrashort X-ray pulse science

    International Nuclear Information System (INIS)

    A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90o Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated ∼ 300 fs, 30 keV (0.4 (angstrom)) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has been

  10. X-ray pulsar rush in 1998

    Energy Technology Data Exchange (ETDEWEB)

    Imanishi, K.; Tsujimoto, K.; Nishiuchi, Mamiko; Yokogawa, J.; Koyama, K. [Kyoto Univ., Faculty of Science, Kyoto (Japan)

    1999-08-01

    We present recent remarkable topics about discoveries of X-ray pulsars. 1. Pulsations from two Soft Gamma-ray Repeaters: These pulsars have enormously strong magnetic field (B {approx} 10{sup 15} G), thus these are called as 'magnetar', new type of X-ray pulsars. 2. New Crab-like pulsars: These discoveries lead to suggesting universality of Crab-like pulsars. 3. An X-ray bursting millisecond pulsar: This is strong evidence for the recycle theory of generating radio millisecond pulsars. 4. X-ray pulsar rush in the SMC: This indicates the younger star formation history in the SMC. (author)

  11. Ultrashort X-ray pulse science

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Alan Hap [Univ. of California, Berkeley, CA (US). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    1998-05-01

    A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90{sup o} Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated {approx} 300 fs, 30 keV (0.4 {angstrom}) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has

  12. Imaging with x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, L.B.; Cauble, B.; Frieders, G.; Koch, J.A.; MacGowan, B.J.; Matthews, D.L.; Mrowka, S.; Ress, D.; Trebes, J.E.; Weiland, T.L.

    1993-11-01

    Collisionally pumped soft x-ray lasers now operate over a wavelength range extending from 35--300 {Angstrom}. These sources have high peak brightness and are now being utilized for x-ray imaging and plasma interferometry. In this paper we will describe our efforts to probe long scalelength plasmas using Moire deflectrometry and soft x-ray imaging. The progress in the development of short pulse x-ray lasers using a double pulse irradiation technique which incorporates a travelling wave pump will also be presented.

  13. X-ray Emission from Elliptical Galaxies

    OpenAIRE

    Sarazin, Craig L.

    1996-01-01

    Elliptical galaxies are generally luminous sources of X-ray radiation, and contain large amounts of hot, interstellar gas. In the brighter X-ray galaxies, the inferred masses of hot gas are consistent with those expected given the present rates of stellar mass loss. The required rates of heating of the gas are also roughly consistent with those expected from the motions of gas losing stars. X-ray observations, particularly X-ray spectra, require a low rate of Type Ia supernova heating and che...

  14. X-ray Observations of Planetary Nebulae

    OpenAIRE

    Guerrero, M. A.; Chu, Y.-H.; Gruendl, R A

    2003-01-01

    Planetary nebulae (PNe) are an exciting addition to the zoo of X-ray sources. Recent Chandra and XMM-Newton observations have detected diffuse X-ray emission from shocked fast winds in PN interiors as well as bow-shocks of fast collimated outflows impinging on the nebular envelope. Point X-ray sources associated with PN central stars are also detected, with the soft X-ray (>0.5 keV) emission from instability shocks in the fast stellar wind itself or from a low-mass companion's coronal activit...

  15. X-ray pulsars: a review

    CERN Document Server

    Caballero, I

    2012-01-01

    Accreting X-ray pulsars are among the most luminous objects in the X-ray sky. In highly magnetized neutron stars (B~10^12 G), the flow of matter is dominated by the strong magnetic field. The general properties of accreting X-ray binaries are presented, focusing on the spectral characteristics of the systems. The use of cyclotron lines as a tool to directly measure a neutron star's magnetic field and to test the theory of accretion are discussed. We conclude with the current and future prospects for accreting X-ray binary studies.

  16. Hard X-ray Modulation Telescope

    Institute of Scientific and Technical Information of China (English)

    LU Fangjun

    2011-01-01

    The Hard X-ray Modulation Telescope (HXMT) will be China's first astronomical satellite. On board HXMT there are three kinds of slat-collimated telescopes, the High Energy X-ray Telescope (HE, 20-250 keV, 5000 cm^2), the Medium Energy X-ray Telescope (ME, 5-30 keV, 952 cm^2), and the Low Energy X-ray Telescope (LE, 1-15 keV, 384 cm^2).

  17. X-rays from the youngest stars

    Science.gov (United States)

    Feigelson, Eric D.

    1994-01-01

    The X-ray properties of classical and weak-lined T Tauri stars are briefly reviewed, emphasizing recent results from the ROSAT satellite and prospects for ASCA. The interpretation of the high level of T Tauri X-rays as enhanced solar-type magnetic activity is discussed and criticized. The census of X-ray emitters is significantly increasing estimates of galactic star formation efficiency, and X-ray emission may be important for self-regulation of star formation. ASCA images will detect star formation regions out to several kiloparsecs and will study the magnetically heated plasma around T Tauri stars. However, images will often suffer from crowding effects.

  18. 成软骨细胞瘤应用X线与CT的临床诊断评价%Clinical Diagnostic Evaluation of Chondroblastoma with X-ray and CT Scanning

    Institute of Scientific and Technical Information of China (English)

    李爱芝

    2014-01-01

    目的:分析X线与CT扫描技术在成软骨细胞瘤应用中的临床疗效,并进行整体的比较观察。方法:选取2013年1月-2014年2月笔者所在医院收治的成软骨细胞瘤患者30例,均进行X线与CT扫描,观察两组在X线与CT扫描状态下的整体情况。结果:通过对30例患者的观察,其中,X线显示中,成软骨细胞瘤的病灶主要表现为圆形或者不规则的呈现出局限性骨破坏区,而CT显示中,病灶呈不同程度的分叶状,在边界相对清晰,呈现出半环形的钙化形式。从整个病理结果的分析来看通过病例检查,30例患者中确诊为成软骨细胞瘤的患者27例,排除3例。X线诊断呈阳性患者21例,排除9例,1例误诊为阴性,7例误诊为阳性;CT扫描诊断呈阳性患者28例,排除2例,有1例误诊呈阴性。其中,X线诊断的敏感性为96.8%(30/31),特异性为12.5%(1/8),CT诊断的敏感性与特异性也分别表现为97.4%(37/38)和100%(1/1),数据采用来源临床运用数据。但是,从诊断的特异性来看,CT诊断要明显高于X线扫描,有一定的差异性。结论:在对成软骨细胞瘤的临床诊断中,采用X线与CT扫描都具有一定的优势,其中CT扫描的特异性更加占据优势,在临床诊断中能提供更加详实的数据,有利于整个病的诊断与鉴别,具有一定的优越性。%Objective:To analyze the effect of X-ray and CT scanning technique in the clinical application of chondroblastoma,and overall comparative observation.Method:Collected from January 2013 to February 2014 in our hospital 30 cases of chondroblastoma,they were given X-ray and CT scanning,two groups were observed in the X-ray and CT scanning state of the overall situation.Result:Through the observation,30 cases,X-ray,chondroblastoma lesions mainly showed round or irregular showed limited bone destruction,CT display showed different degrees of lobulated,in the relative

  19. CT or not CT—that is the question. Whether ‘tis better to evaluate clinically and x ray than to undertake a CT head scan!

    OpenAIRE

    Macgregor, D; McKie, L.

    2005-01-01

    Objective: To evaluate the usage of computed tomography (CT) head scanning in children at the Royal Aberdeen Children's Hospital after the publication of the National Institute of Clinical Excellence (NICE) guidelines on the management of head injury.

  20. Poor interpretation of chest X-rays by junior doctors

    DEFF Research Database (Denmark)

    Christiansen, Janus Mølgaard; Gerke, Oke; Karstoft, Jens;

    2014-01-01

    INTRODUCTION: Studies targeting medical students and junior doctors have shown that their radiological skills are insufficient. Despite the widespread use of chest X-ray; however, a study of Danish junior doctors' skills has not previously been performed. MATERIAL AND METHODS: A total of 22...... participants per-used a standardised series of ten chest X-rays. The test used a multiple-choice form for each image, and the clinical data and the tentative diagnosis of each image were also made available to the participants. For each image, the participant chose a single primary diagnosis; and for each......): 0.41-0.57) and the specificity to 0.55 (95% CI: 0.41-0.68). CONCLUSION: Based on the results from this study, we conclude that BCE doctors do not meet the minimum requirements for radiological diagnostic skills for the use of chest X-ray that were established for this study. FUNDING: not relevant...

  1. Evaluation of the Beam Quality of Intraoral X-ray Equipment using Intraoral Standard Films

    International Nuclear Information System (INIS)

    This study was to evaluate the beam quality of intraoral X-ray equipment used at Yonsei University Dental Hospital (YUDH) using the half value layer (HVL) and the characteristic curve of intraoral standard X-ray film. The study was done using the intraoral X-ray equipment used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. Most of the HVLs of intraoral X-ray equipment were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANPAS 601 model and REX 601 model at operative dentistry department, the X-70S model of prosthodontic dentistry department, and the REX 601 model at the student clinic were relatively low. HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X-ray equipment should be managed in the planned and organized fashion.

  2. Practical method for determination of air kerma by use of an ionization chamber toward construction of a secondary X-ray field to be used in clinical examination rooms.

    Science.gov (United States)

    Maehata, Itsumi; Hayashi, Hiroaki; Kimoto, Natsumi; Takegami, Kazuki; Okino, Hiroki; Kanazawa, Yuki; Tominaga, Masahide

    2016-07-01

    We propose a new practical method for the construction of an accurate secondary X-ray field using medical diagnostic X-ray equipment. For accurate measurement of the air kerma of an X-ray field, it is important to reduce and evaluate the contamination rate of scattered X-rays. To determine the rate quantitatively, we performed the following studies. First, we developed a shield box in which an ionization chamber could be set at an inner of the box to prevent detection of the X-rays scattered from the air. In addition, we made collimator plates which were placed near the X-ray source for estimation of the contamination rate by scattered X-rays from the movable diaphragm which is a component of the X-ray equipment. Then, we measured the exposure dose while changing the collimator plates, which had diameters of 25-90 mm(ϕ). The ideal value of the exposure dose was derived mathematically by extrapolation to 0 mm(ϕ). Tube voltages ranged from 40 to 130 kV. Under these irradiation conditions, we analyzed the contamination rate by the scattered X-rays. We found that the contamination rates were less than 1.7 and 2.3 %, caused by air and the movable diaphragm, respectively. The extrapolated value of the exposure dose has been determined to have an uncertainty of 0.7 %. The ionization chamber used in this study was calibrated with an accuracy of 5 %. Using this kind of ionization chamber, we can construct a secondary X-ray field with an uncertainty of 5 %.

  3. X-ray imaging using a tunable coherent X-ray source based on parametric X-ray radiation

    International Nuclear Information System (INIS)

    A novel X-ray source based on parametric X-ray radiation (PXR) has been employed for X-ray imaging at the Laboratory for Electron Beam Research and Application (LEBRA), Nihon University. Notable features of PXR are tunable energy, monochromaticity with spatial chirp, narrow local bandwidth and spatial coherence. Since the X-ray beam from the PXR system has a large irradiation area with uniform flux density, the PXR-based source is suited for X-ray imaging, especially for application to phase-contrast imaging. Despite the cone-like X-ray beam, diffraction-enhanced imaging (DEI) can be employed as a phase contrast imaging technique. DEI experiments were performed using 14- to 34-keV X-rays and the phase-gradient images were obtained. The results demonstrated the capability of PXR as an X-ray source for phase-contrast imaging with a large irradiation field attributed to the cone-beam effect. Given the significant properties of the LEBRA-PXR source, the result suggests the possible construction of a compact linac-driven PXR-Imaging instrument and its application to medical diagnoses

  4. Diagnosis and X-ray findings in aluminium dust pneumoconiosis

    International Nuclear Information System (INIS)

    Despite effective regulations established by professional organizations and business health programs, aluminiumcaused pneumoconiosis still occurs. Therefore, the etiology, clinical appearance, histological confirmation, and X-ray findings are presented from a case which was followed for ten years. The differential diagnosis indicated by the radiologic findings are discussed. (orig.)

  5. On the universal X-ray luminosity function of binary X-ray sources in galaxies

    OpenAIRE

    Postnov, K. A.

    2002-01-01

    The empirically determined universal power-law shape of X-ray luminosity function of high mass X-ray binaries in galaxies is explained by fundamental mass-luminosity and mass-radius relations for massive stars.

  6. SN X-ray Progenitor?

    Science.gov (United States)

    2008-01-01

    Identifying stars that explode, right before they explode, is a tricky proposition since the end of starlife comes swiftly: in thermonuclear deflagrations, in nuclear exhaustion, or maybe in a rapid swirling merger of two dead stellar cores. On the right in the image above is an image of the galaxy NGC 1404 taken by the UV/optical Telescope (UVOT) on the Swift observatory. The circle surrounds SN 2007on, a supernova of Type Ia produced by the explosion of a white dwarf star in a binary system. These types of supernovae are important since they are believed to be 'standard candles', events which have the same intrinsic brightness which can serve as an important yardstick to measure cosmic distances. On the left is an image of the same galaxy taken by the Chandra X-ray observatory four years before the supernova. Conspicuous in the SN source circle is a bright source in the Chandra image, believed to be emission from a compact object+normal star companion: a similar system to the supposed precursor of SN 2007on. If true this would be the first time a Type Ia supernova precursor has ever been seen. But astronomers are still debating whether the Chandra source really is the precursor or not; it seems there's a slight but significant difference in the location of the Chandra source and the supernova. Stay tuned for more developments.

  7. X-ray radiography facility

    International Nuclear Information System (INIS)

    The paper described a radiographic apparatus containing a radiation source, a diaphragm with collimating windows and a cassette holder with a cassette for the X-ray film. In order to increase the efficiency and quality of monitoring, the diaphragm and the cassette are made in the form of cylindrical shells, the centre of curvature of which coincides with the position of the radiation source focus. Each collimating window of the diaphragm is made in the form of two coaxially connected truncated cones, joined at the large bases in such a way that the angle at the vertex of the cone nearer the source is not less than the central angle with the vertex at the focus of the radiation source supported by the larger base, and 15-300 less than the angle at the vertex of the cone further from the source. By this means monitoring efficiency is increased by a factor of 1.5-2 and the quality of the radiographs improved. The apparatus is used for flaw detection in cylindrical objects. (author)

  8. X-ray detector for automatic exposure control using ionization chamber filled with xenon gas

    CERN Document Server

    Nakagawa, A; Yoshida, T

    2003-01-01

    This report refers to our newly developed X-ray detector for reliable automatic X-ray exposure control, which is to be widely used for X-ray diagnoses in various clinical fields. This new detector utilizes an ionization chamber filled with xenon gas, in contrast to conventional X-ray detectors which use ionization chambers filled with air. Use of xenon gas ensures higher sensitivity and thinner design of the detector. The xenon gas is completely sealed in the chamber, so that the influence of the changes in ambient environments is minimized. (author)

  9. Diffraction leveraged modulation of X-ray pulses using MEMS-based X-ray optics

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Daniel; Shenoy, Gopal; Wang, Jin; Walko, Donald A.; Jung, Il-Woong; Mukhopadhyay, Deepkishore

    2016-08-09

    A method and apparatus are provided for implementing Bragg-diffraction leveraged modulation of X-ray pulses using MicroElectroMechanical systems (MEMS) based diffractive optics. An oscillating crystalline MEMS device generates a controllable time-window for diffraction of the incident X-ray radiation. The Bragg-diffraction leveraged modulation of X-ray pulses includes isolating a particular pulse, spatially separating individual pulses, and spreading a single pulse from an X-ray pulse-train.

  10. Accelerator-driven X-ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  11. X-ray topography and multiple diffraction

    International Nuclear Information System (INIS)

    A short summary on X-ray topography, which is based on the dynamical theory of X-ray diffraction, is made. The applications and properties related to the use of the multiple diffraction technique are analized and discussed. (L.C.)

  12. Soft x rays for radiobiological studies

    International Nuclear Information System (INIS)

    Lethal effects and chromosome aberrations induced in cells exposed to low energy (soft) X rays demonstrated that these relatively low energy X rays are just as effective as those of higher energy for radiobiological studies, and even more effective for irradiating cultured mammalian cells than laboratory animals. (author)

  13. Coccidioidomycosis - chest x-ray (image)

    Science.gov (United States)

    This chest x-ray shows the affects of a fungal infection, coccidioidomycosis. In the middle of the left lung (seen on the ... defined borders. Other diseases that may explain these x-ray findings include lung abscesses, chronic pulmonary tuberculosis, chronic ...

  14. X-Ray Detection Visits the Classroom

    Science.gov (United States)

    Peralta, Luis; Farinha, Ana; Pinto, Ana

    2008-01-01

    Film has been used to detect x-rays since the early days of their discovery by Rontgen. Although nowadays superseded by other techniques, film still provides a cheap means of x-ray detection, making it attractive in high-school or undergraduate university courses. If some sort of quantitative result is required, the film's optical absorbance or…

  15. 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 ...

  16. Tracing the X-Ray Trail

    Science.gov (United States)

    What you need to know about… Tracing the X-ray Trail If you’ve just completed an x-ray, computed tomography (CT), magnetic resonance (MR) Start here! or other diagnostic imaging procedure, you probably want to know when you will ... los rayos X Si acaba de hacerse una radiografía, tomografía ¡Empezar ...

  17. Proton induced X-ray emission analysis

    International Nuclear Information System (INIS)

    The developments in proton induced X-ray emission analysis are reviewed. Techniques for analyzing thick and thin samples of different origin are described. Discussions on the application of proton induced X-ray emission analysis in different fields, comparison of the sensitivity of this method with other analytical techniques, its limitations and possible improvements are presented

  18. X-ray scattering measurements from thin-foil x-ray mirrors

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; BYRNAK, BP; Hornstrup, Allan;

    1992-01-01

    Thin foil X-ray mirrors are to be used as the reflecting elements in the telescopes of the X-ray satellites Spectrum-X-Gamma (SRG) and ASTRO-D. High resolution X-ray scattering measurements from the Au coated and dip-lacquered Al foils are presented. These were obtained from SRG mirrors positione...

  19. Characterization of Metalloproteins and Biomaterials by X-ray Absorption Spectroscopy and X-ray Diffraction

    DEFF Research Database (Denmark)

    Frankær, Christian Grundahl

    This thesis presents thework on combining complementary X-rays techniques for studying the structures of proteins and other biomaterials, and consists of three different projects: (i) Characterization of protein powders with X-ray powder diffraction (XRPD). (ii) The combination of X-ray crystallo...

  20. Soft X-Ray Spectra of AGN Discovered Via Their Hard X-Ray

    Science.gov (United States)

    Schwartz, Daniel

    1998-01-01

    This final report is a study of the Active Galactic Nuclei (AGN). Investigation of the soft x-ray spectra of AGN were performed by using their hard x-ray emission. ROSAT observations of AGN was also performed, which allowed for the study of these x-ray spectra and the structures of 7 clusters of galaxies.

  1. X-ray devices contributing to sophistication of X-ray diagnostic systems

    International Nuclear Information System (INIS)

    X-ray tubes to generate X-rays, as well as X-ray image intensifiers (I.I.s) and X-ray flat panel detectors (FPDs) to convert X-ray images into electronic signals, are key devices in X-ray diagnostic systems, which are playing a major role in the advancement of diagnosis and treatment. Toshiba Electron Tubes and Devices Co., Ltd. has been offering optimal products incorporating the most advanced technologies to customers through continuous technological innovations. These include a high-sensitivity technology for X-ray I.I.s and X-ray FPDs to suppress patient exposure doses, a focal spot design technology for X-ray tubes and high-resolution technologies for X-ray I.I.s and X-ray FPDs that enhance image quality and make it possible to detect smaller lesion areas, and a noise reduction technology for X-ray tubes to realize a comfortable medical environment with reduced stress on both patients and medical staff. (author)

  2. Optical cone beam tomography of Cherenkov-mediated signals for fast 3D dosimetry of x-ray photon beams in water

    Energy Technology Data Exchange (ETDEWEB)

    Glaser, Adam K., E-mail: Adam.K.Glaser@dartmouth.edu, E-mail: Brian.W.Pogue@dartmouth.edu; Andreozzi, Jacqueline M. [Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755 (United States); Zhang, Rongxiao [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States); Pogue, Brian W., E-mail: Adam.K.Glaser@dartmouth.edu, E-mail: Brian.W.Pogue@dartmouth.edu [Thayer School of Engineering and Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States); Gladstone, David J. [Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03766 (United States)

    2015-07-15

    Purpose: To test the use of a three-dimensional (3D) optical cone beam computed tomography reconstruction algorithm, for estimation of the imparted 3D dose distribution from megavoltage photon beams in a water tank for quality assurance, by imaging the induced Cherenkov-excited fluorescence (CEF). Methods: An intensified charge-coupled device coupled to a standard nontelecentric camera lens was used to tomographically acquire two-dimensional (2D) projection images of CEF from a complex multileaf collimator (MLC) shaped 6 MV linear accelerator x-ray photon beam operating at a dose rate of 600 MU/min. The resulting projections were used to reconstruct the 3D CEF light distribution, a potential surrogate of imparted dose, using a Feldkamp–Davis–Kress cone beam back reconstruction algorithm. Finally, the reconstructed light distributions were compared to the expected dose values from one-dimensional diode scans, 2D film measurements, and the 3D distribution generated from the clinical Varian ECLIPSE treatment planning system using a gamma index analysis. A Monte Carlo derived correction was applied to the Cherenkov reconstructions to account for beam hardening artifacts. Results: 3D light volumes were successfully reconstructed over a 400 × 400 × 350 mm{sup 3} volume at a resolution of 1 mm. The Cherenkov reconstructions showed agreement with all comparative methods and were also able to recover both inter- and intra-MLC leaf leakage. Based upon a 3%/3 mm criterion, the experimental Cherenkov light measurements showed an 83%–99% pass fraction depending on the chosen threshold dose. Conclusions: The results from this study demonstrate the use of optical cone beam computed tomography using CEF for the profiling of the imparted dose distribution from large area megavoltage photon beams in water.

  3. Optical cone beam tomography of Cherenkov-mediated signals for fast 3D dosimetry of x-ray photon beams in water

    International Nuclear Information System (INIS)

    Purpose: To test the use of a three-dimensional (3D) optical cone beam computed tomography reconstruction algorithm, for estimation of the imparted 3D dose distribution from megavoltage photon beams in a water tank for quality assurance, by imaging the induced Cherenkov-excited fluorescence (CEF). Methods: An intensified charge-coupled device coupled to a standard nontelecentric camera lens was used to tomographically acquire two-dimensional (2D) projection images of CEF from a complex multileaf collimator (MLC) shaped 6 MV linear accelerator x-ray photon beam operating at a dose rate of 600 MU/min. The resulting projections were used to reconstruct the 3D CEF light distribution, a potential surrogate of imparted dose, using a Feldkamp–Davis–Kress cone beam back reconstruction algorithm. Finally, the reconstructed light distributions were compared to the expected dose values from one-dimensional diode scans, 2D film measurements, and the 3D distribution generated from the clinical Varian ECLIPSE treatment planning system using a gamma index analysis. A Monte Carlo derived correction was applied to the Cherenkov reconstructions to account for beam hardening artifacts. Results: 3D light volumes were successfully reconstructed over a 400 × 400 × 350 mm3 volume at a resolution of 1 mm. The Cherenkov reconstructions showed agreement with all comparative methods and were also able to recover both inter- and intra-MLC leaf leakage. Based upon a 3%/3 mm criterion, the experimental Cherenkov light measurements showed an 83%–99% pass fraction depending on the chosen threshold dose. Conclusions: The results from this study demonstrate the use of optical cone beam computed tomography using CEF for the profiling of the imparted dose distribution from large area megavoltage photon beams in water

  4. Automated Quality Assurance of Medical Digital X-Ray Equipment

    International Nuclear Information System (INIS)

    Quality assurance of the x-ray equipment includes a set of various tests among which are installation and periodic exams performed by qualified engineers as well as daily routine tests carried out by the medical staff of the Radiology Department. As a rule, the decision concerning the applicability of the x-ray equipment for using in clinical studies is made on the basis of the routine tests results. The presented method is based on the detector's output signals, Signal-to-Noise Ratio and Modulation Transfer Function evaluation in automated way using the simple test-object's digital image registered with given geometry and x-ray exposure parameters settings. Rectangular 20 mm thick aluminum plate with fixed 1 mm thick well-finished steel edge (for general x-ray radiography/fluoroscopy systems) or 2 mm thick aluminum plate with fixed 1 mm thick aluminum well-finished edge (for digital x-ray mammography systems) can be used as a test equipment. Relevant to the decision concerning the x-ray device operation status are the parameters: deviations from the reference levels of the tube voltage and mAs as well as internal detector's noise variance and detector's gain deviations. Everyday testing procedure includes the following steps. On the first step the roentgenographer places the test-object at the center of the detector's surface, makes an exposure with specified parameters setting and geometry and after this, test results are displayed on the work station monitor or console screen in automatic way. In order to provide an automated regime of the presenting algorithm, the software must be integrated with the program module intended for the x-ray device control. The use of the presented method in clinical practice provides the reliable daily monitoring of the x-ray equipment operation status prior to its utilizing for patient diagnostic process. As a rule, it will take not more than 3-5 minutes for the roentgenographer to complete the routine

  5. An X-ray view of quasars

    CERN Document Server

    Singh, K P

    2013-01-01

    I present an overview of observational studies of quasars of all types, with particular emphasis on X-ray observational studies. The presentation is based on the most popularly accepted unified picture of quasars - collectively referred to as AGN (active galactic nuclei) in this review. Characteristics of X-ray spectra and X-ray variability obtained from various X-ray satellites over the last 5 decades have been presented and discussed. The contribution of AGN in understanding the cosmic X-ray background is discussed very briefly. Attempt has been made to provide up-to-date information; however, this is a vast subject and this presentation is not intended to be comprehensive.

  6. X-ray Fourier ptychographic microscopy

    CERN Document Server

    Simons, H; Guigay, J P; Detlefs, C

    2016-01-01

    Following the recent developement of Fourier ptychographic microscopy (FPM) in the visible range by Zheng et al. (2013), we propose an adaptation for hard x-rays. FPM employs ptychographic reconstruction to merge a series of low-resolution, wide field of view images into a high-resolution image. In the x-ray range this opens the possibility to overcome the limited numerical aperture of existing x-ray lenses. Furthermore, digital wave front correction (DWC) may be used to charaterize and correct lens imperfections. Given the diffraction limit achievable with x-ray lenses (below 100 nm), x-ray Fourier ptychographic microscopy (XFPM) should be able to reach resolutions in the 10 nm range.

  7. High Energy Vision: Processing X-rays

    CERN Document Server

    DePasquale, Joseph; Edmonds, Peter

    2015-01-01

    Astronomy is by nature a visual science. The high quality imagery produced by the world's observatories can be a key to effectively engaging with the public and helping to inspire the next generation of scientists. Creating compelling astronomical imagery can, however, be particularly challenging in the non-optical wavelength regimes. In the case of X-ray astronomy, where the amount of light available to create an image is severely limited, it is necessary to employ sophisticated image processing algorithms to translate light beyond human vision into imagery that is aesthetically pleasing while still being scientifically accurate. This paper provides a brief overview of the history of X-ray astronomy leading to the deployment of NASA's Chandra X-ray Observatory, followed by an examination of the specific challenges posed by processing X-ray imagery. The authors then explore image processing techniques used to mitigate such processing challenges in order to create effective public imagery for X-ray astronomy. ...

  8. X-Rays from Green Pea Analogs

    Science.gov (United States)

    Brorby, Matthew

    2014-09-01

    X-rays may have contributed to the heating and reionization of the IGM in the early universe. High mass X-ray binaries (HMXB) within small, low-metallicity galaxies are expected to be the main source of X-rays at this time. Since studying these high-redshift galaxies is currently impossible, we turn to local analogs that have the same properties the galaxies in the early are expected to have. A number of recent studies have shown an enhanced number of HMXBs in nearby low metallicity galaxies. We propose to observe a sample of metal-deficient luminous compact galaxies (LCG) in order to determine if the X-ray luminosity is enhanced relative to SFR, thereby providing further evidence to the importance of X-rays in the early universe.

  9. 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...

  10. X-ray findings in patients with miliary appearance of metallic mercury after suicide attempt

    International Nuclear Information System (INIS)

    This case report evaluates X-ray findings in patients with miliary accumulation of mercury observed after parenteral application of metallic mercury in a suizide attempt. There are certain discrepancies between clinical symptoms and the X-ray findings. A clear demonstration of mercury in coronary blood vessels is possible by fluoroscopy. (orig.)

  11. Procedure and data evaluation to evaluate fetal absorbed dose in clinical radiated (X-ray) pregnant women; Descripcion del procedimiento y evaluacion de datos de estimacion de dosis absorbidas en feto para pacientes gestantes como consecuencia de la realizacion de pruebas radiodiagnosticas

    Energy Technology Data Exchange (ETDEWEB)

    Calama Santiago, J. A.; Gonzalez Ruiz, C.; Olivares Munoz, M. P.

    2006-07-01

    This paper details the procedure followed in our hospital to evaluate fetal absorbed dose in clinical radiated (X-ray) pregnant women. The description covers data request, calculations and report generation, and show the estimated dose since year 2000, comparing the results with the published data in the literature. (Author)

  12. Dose optimization in pediatric cardiac x-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gislason, Amber J.; Davies, Andrew G.; Cowen, Arnold R. [LXi Research, Division of Medical Physics, University of Leeds, Worsley Building, Clarendon Way, Leeds LS2 9JT (United Kingdom)

    2010-10-15

    Purpose: The aim of this research was to explore x-ray beam parameters with intent to optimize pediatric x-ray settings in the cardiac catheterization laboratory. This study examined the effects of peak x-ray tube voltage (kVp) and of copper (Cu) x-ray beam filtration independently on the image quality to dose balance for pediatric patient sizes. The impact of antiscatter grid removal on the image quality to dose balance was also investigated. Methods: Image sequences of polymethyl methacrylate phantoms approximating chest sizes typical of pediatric patients were captured using a modern flat-panel receptor based x-ray imaging system. Tin was used to simulate iodine-based contrast medium used in clinical procedures. Measurements of tin detail contrast and flat field image noise provided the contrast to noise ratio. Entrance surface dose (ESD) and effective dose (E) measurements were obtained to calculate the figure of merit (FOM), CNR{sup 2}/dose, which evaluated the dose efficiency of the x-ray parameters investigated. The kVp, tube current (mA), and pulse duration were set manually by overriding the system's automatic dose control mechanisms. Images were captured with 0, 0.1, 0.25, 0.4, and 0.9 mm added Cu filtration, for 50, 55, 60, 65, and 70 kVp with the antiscatter grid in place, and then with it removed. Results: For a given phantom thickness, as the Cu filter thickness was increased, lower kVp was favored. Examining kVp alone, lower values were generally favored, more so for thinner phantoms. Considering ESD, the 8.5 cm phantom had the highest FOM at 50 kVp using 0.4 mm of Cu filtration. The 12 cm phantom had the highest FOM at 55 kVp using 0.9 mm Cu, and the 16 cm phantom had highest FOM at 55 kVp using 0.4 mm Cu. With regard to E, the 8.5 and 12 cm phantoms had the highest FOM at 50 kVp using 0.4 mm of Cu filtration, and the 16 cm phantom had the highest FOM at 50 kVp using 0.25 mm Cu. Antiscatter grid removal improved the FOM for a given set of x-ray

  13. X-ray Spectral Variation of Eta Carinae through the 2003 X-ray Minimum

    OpenAIRE

    Hamaguchi, Kenji; Corcoran, Michael F.; Gull, Theodore; Ishibashi, Kazunori; Pittard, Julian M.; Hillier, D. John; Damineli, Augusto; Davidson, Kris; Nielsen, Krister E.; Kober, Gladys Vieira

    2007-01-01

    We report the results of an X-ray observing campaign on the massive, evolved star Eta Carinae, concentrating on the 2003 X-ray minimum as seen by the XMM-Newton observatory. These are the first spatially-resolved X-ray monitoring observations of the stellar X-ray spectrum during the minimum. The hard X-ray emission, believed to be associated with the collision of Eta Carinae's wind with the wind from a massive companion star, varied strongly in flux on timescales of days, but not significantl...

  14. Large area soft x-ray collimator to facilitate x-ray optics testing

    Science.gov (United States)

    Espy, Samuel L.

    1994-01-01

    The first objective of this program is to design a nested conical foil x-ray optic which will collimate x-rays diverging from a point source. The collimator could then be employed in a small, inexpensive x-ray test stand which would be used to test various x-ray optics and detector systems. The second objective is to demonstrate the fabrication of the x-ray reflectors for this optic using lacquer-smoothing and zero-stress electroforming techniques.

  15. First X-ray fluorescence CT experimental results at the SSRF X-ray imaging beamline

    Institute of Scientific and Technical Information of China (English)

    DENG Biao; YANG Qun; XIE Hong-Lan; DU Guo-Hao; XIAO Wi-Qiao

    2011-01-01

    X-ray fluorescence CT is a non-destructive technique for detecting elemental composition and distribution inside a specimen. In this paper, the first experimental results of X-ray fluorescence CT obtained at the SSRF X-ray imaging beamline (BL13W1) are described. The test samples were investigated and the 2D elemental image was reconstructed using a filtered back-projection algorithm. In the sample the element Cd was observed. Up to now, the X-ray fluorescence CT could be carried out at the SSRF X-ray imaging beamline.

  16. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    OpenAIRE

    Miaja-Avila, L.; G. C. O'Neil; Uhlig, J.; C. L. Cromer; Dowell, M. L.; Jimenez, R.; Hoover, A. S.; Silverman, K. L.; Ullom, J. N.

    2015-01-01

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼106 photons/s, by focusing the produced x-rays with a polycapillary opti...

  17. REVIEW: X-ray computed tomography

    Science.gov (United States)

    Kalender, Willi A.

    2006-07-01

    X-ray computed tomography (CT), introduced into clinical practice in 1972, was the first of the modern slice-imaging modalities. To reconstruct images mathematically from measured data and to display and to archive them in digital form was a novelty then and is commonplace today. CT has shown a steady upward trend with respect to technology, performance and clinical use independent of predictions and expert assessments which forecast in the 1980s that it would be completely replaced by magnetic resonance imaging. CT not only survived but exhibited a true renaissance due to the introduction of spiral scanning which meant the transition from slice-by-slice imaging to true volume imaging. Complemented by the introduction of array detector technology in the 1990s, CT today allows imaging of whole organs or the whole body in 5 to 20 s with sub-millimetre isotropic resolution. This review of CT will proceed in chronological order focussing on technology, image quality and clinical applications. In its final part it will also briefly allude to novel uses of CT such as dual-source CT, C-arm flat-panel-detector CT and micro-CT. At present CT possibly exhibits a higher innovation rate than ever before. In consequence the topical and most recent developments will receive the greatest attention.

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

    International Nuclear Information System (INIS)

    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)

  19. Robust femur condyle disambiguation on biplanar X-rays.

    Science.gov (United States)

    Serrurier, Antoine; Quijano, Sergio; Nizard, Remy; Skalli, Wafa

    2012-12-01

    Three-dimensional (3D) reconstruction of the skeleton from biplanar X-rays relies on scarce information digitalised by an operator on both frontal and lateral radiographs. In clinical routine, difficulties occur for non-skilled operators to discriminate the medial from the lateral femur condyle on the lateral view. Our study proposes an algorithm able to detect automatically a possible inversion of the two condyles by the operator at an early stage of the reconstruction process. It relies on the computation of two 3D femur surfaces, one directly from the operator digitalisation and the other from the same digitalisation with medial and lateral condyles automatically swapped. Pairs of virtual biplanar X-rays are computed for both reconstructions and the closest pair to the original X-rays is selected on the basis of similarity measures, pointing the correct 3D surface. The algorithm shows a success rate higher than 85% for both asymptomatic and pathological femurs whatever the initial condyle digitalisation of the operator, bringing automatically non-skilled operators acting in clinical routine to the level of skilled operators. This study validates moreover the proof-of-concept of automatic shape adjustments of a 3D surface on the basis of similarity measures in the process of 3D reconstruction from biplanar X-rays. PMID:22349135

  20. Dual-energy X-ray CT and the extension to polychromatic X-ray CT

    International Nuclear Information System (INIS)

    We have developed dual energy X-ray CT using monochromatic X-ray beams. From the dual-energy X-ray CT, we can obtain distributions of an electron density and an effective atomic number in a human body. Especially, the electron density is very important for the heavy ion radiotherapy. Now, we adopted new array-detector to know the energy of incident photons as well as detect the position and the number of photons. We carry out the experiment of the dual-energy X-ray CT at the beamline of KEK and SPring-8 as a fundamental study for the polychromatic X-ray CT. We will show the preliminary result of this experiments and the feasibility of a quantitative polychromatic X-ray CT as an advanced method of monochromatic X-ray CT in this study. (author)

  1. Cell survival studies using ultrasoft x rays

    International Nuclear Information System (INIS)

    Cell survival was studied for V79 hamster, 10T1/2 mouse, and human skin fibroblast cell lines, using carbon K (0.28 keV), copper K (8.0 keV), and 250 kVp x rays. Because of the rapid attenuation of the carbon x rays, cellular dimensions at the time of exposure were measured using optical and electron microscopy, and frequency distributions of mean dose absorbed by the cell nucleus were obtained. The results indicate that the differences in cell killing between ultra-soft and hard x rays may depend on the nuclear thickness of the cells. Studies of the effects of hypoxia on V79 and 10T1/2 cells using carbon K, aluminum K (1.5 keV), and copper K x rays show decreasing OER values with decreasing x-ray energy and no difference between the two cell lines. Age response studies with V79 cells show similar cell-cycle variation of survival for carbon K and aluminum K x rays as for hard x rays

  2. Toward Adaptive X-Ray Telescopes

    Science.gov (United States)

    O'Dell, Stephen L.; Atkins, Carolyn; Button, Tim W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peer; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffrey J.; Michette, Alan G.; Ramsey, Brian D.; Reid, Paul B.; Rodriguez Sanmartin, Daniel; Saha, Timo T.; Schwartz, Daniel A.; Trolier-McKinstry, Susan; Wilke, Rudeger H. T.; Willingale, Richard; Zhang, William W.

    2011-01-01

    Future x-ray observatories will require high-resolution (less than 1 inch) optics with very-large-aperture (greater than 25 square meter) areas. Even with the next generation of heavy-lift launch vehicles, launch-mass constraints and aperture-area requirements will limit the surface areal density of the grazing-incidence mirrors to about 1 kilogram per square meter or less. Achieving sub-arcsecond x-ray imaging with such lightweight mirrors will require excellent mirror surfaces, precise and stable alignment, and exceptional stiffness or deformation compensation. Attaining and maintaining alignment and figure control will likely involve adaptive (in-space adjustable) x-ray optics. In contrast with infrared and visible astronomy, adaptive optics for x-ray astronomy is in its infancy. In the middle of the past decade, two efforts began to advance technologies for adaptive x-ray telescopes: The Generation-X (Gen-X) concept studies in the United States, and the Smart X-ray Optics (SXO) Basic Technology project in the United Kingdom. This paper discusses relevant technological issues and summarizes progress toward adaptive x-ray telescopes.

  3. Toward active x-ray telescopes

    Science.gov (United States)

    O'Dell, Stephen L.; Atkins, Carolyn; Button, Timothy W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peter; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffery J.; Michette, Alan G.; Ramsey, Brian D.; Reid, Paul B.; Rodriguez Sanmartin, Daniel; Saha, Timo T.; Schwartz, Daniel A.; Trolier-McKinstry, Susan; Wilke, Rudeger H. T.; Willingale, Richard; Zhang, William W.

    2011-09-01

    Future x-ray observatories will require high-resolution ( 25 m2) areas. Even with the next generation of heavy-lift launch vehicles, launch-mass constraints and aperture-area requirements will limit the areal density of the grazing-incidence mirrors to about 1 kg/m2 or less. Achieving sub-arcsecond x-ray imaging with such lightweight mirrors will require excellent mirror surfaces, precise and stable alignment, and exceptional stiffness or deformation compensation. Attaining and maintaining alignment and figure control will likely involve active (in-space adjustable) x-ray optics. In contrast with infrared and visible astronomy, active optics for x-ray astronomy is in its infancy. In the middle of the past decade, two efforts began to advance technologies for adaptive x-ray telescopes: The Smart X-ray Optics (SXO) Basic Technology project in the United Kingdom (UK) and the Generation-X (Gen-X) concept studies in the United States (US). This paper discusses relevant technological issues and summarizes progress toward active x-ray telescopes.

  4. Spectral reconstruction of the flash X-ray generated by Dragon-I LIA based on transmission measurements

    Institute of Scientific and Technical Information of China (English)

    曹靖; 肖睿; 陈楠; 曹宏睿; 阴泽杰

    2015-01-01

    The Dragon-I linear induction accelerator (LIA) at China Academy of Engineering Physics generates 20 MeV flash X-rays mainly for radiography applications in fluid dynamics. Its spectral information is quite important for diagnostic X-ray imaging applications, but because of its short pulse and great radiation intensity, direct measurement is impossible. In this work, we propose a new method based on transmission measurements to obtain the flash X-ray spectrum. Pure iron cylinders were used as attenuation material, and alanine dosimeters were attached on their rear bottom to record the dose after different degrees of attenuation. Iterative least square method was used to unfold the spectrum, while Geant4 Monte Carlo code was used to simulate the X-ray spectrum. The unfolded spectrum and the simulated spectrum have a high degree of consistency, with the reduced chi-square value of 0.044. This shows that the method is reliable in estimating megavoltage high-intensity X-ray spectrum.

  5. The combined treatment of prostate cancer (stage C) with definitive megavoltage irradiation and fast neutrons (DT, 14 MeV)

    International Nuclear Information System (INIS)

    We treated between 1977 and 1979 patients with low differentiated prostate cancer stage C with megavoltage irradiation (42 MeV-X-rays) in the whole pelvis, including the prostate, up to 30-45 Gy/3-4,5 weeks; thereafter we irradiated a boost on the primary with 6-8 isocentric fields of fast neutrons up to 3,9-8,4 Gy/1-2 weeks. The 13 treated patients had all clinically complete regression of the tumor, they are without local recidive since 9-43 months. Biopsies of 3 patients are morphologic free of tumor cells already 8-12 months after irradiation. Distant metastases occurred in 3 patients: 2 are living since 16 and 43 months, 1 died after 24 months. All patients are free of serious chronic side effects at bladder and rectum, only 1 lives with a slight proctitis after therapy with only 2 opposing fields. The 14th patient is treated on behalf of a local recidive after prostatectomy (anaplastic prostate cancer) and a big pararectal metastasis; we irradiated the whole pelvis with fast neutrons up to a dose of 15,3 Gy/4 weeks (total dose, n + γ): The patient is free of pains since 9 months and without tumor in computer tomography, and free of serious chronic complications. (orig./MG)

  6. Two-dimensional x-ray diffraction

    CERN Document Server

    He, Bob B

    2009-01-01

    Written by one of the pioneers of 2D X-Ray Diffraction, this useful guide covers the fundamentals, experimental methods and applications of two-dimensional x-ray diffraction, including geometry convention, x-ray source and optics, two-dimensional detectors, diffraction data interpretation, and configurations for various applications, such as phase identification, texture, stress, microstructure analysis, crystallinity, thin film analysis and combinatorial screening. Experimental examples in materials research, pharmaceuticals, and forensics are also given. This presents a key resource to resea

  7. Imaging Cellular Architecture with X-rays

    OpenAIRE

    Larabell, Carolyn A.; Nugent, Keith A.

    2010-01-01

    X-ray imaging of biological samples is progressing rapidly. In this paper we review the progress to date in high resolution imaging of cellular architecture. In particular we survey the progress in soft X-ray tomography and argue that the field is coming of age and that important biological insights are starting to emerge. We then review the new ideas based on coherent diffraction. These methods are at a much earlier stage of development but, as they eliminate the need for X-ray optics, have ...

  8. The Future of X-Ray Optics

    Science.gov (United States)

    Weisskopf, Martin C.

    2013-01-01

    The most important next step is the development of X-ray optics comparable to (or better than) Chandra in angular resolution that far exceed Chandra s effective area. Use the long delay to establish an adequately funded, competitive technology program along the lines I have recommended. Don't be diverted from this objective, except for Explorer-class missions. Progress in X-ray optics, with emphasis on the angular resolution, is central to the paradigm-shifting discoveries and the contributions of X-ray astronomy to multiwavelength astrophysics over the past 51 years.

  9. Ten years of X-ray interferometry

    International Nuclear Information System (INIS)

    X-ray interferometers were the first optical instruments which utilized many Bragg reflecting components in monolithic blocks of perfect crystal. They have made important contributions to our knowledge of fundamental constants, of Bragg reflection x-ray optics, of strains and defects in crystals and of the optical constants of materials in the x-ray region of the electromagnetic spectrum. Based on an oversimplified optical analogue, their mode of operation is described in detail. Current applications of crystal interferometers and future work is briefly reviewed. (author)

  10. X-ray phase-contrast methods

    Energy Technology Data Exchange (ETDEWEB)

    Lider, V. V., E-mail: lider@ns.crys.ras.ru; Kovalchuk, M. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2013-11-15

    This review is devoted to a comparative description of the methods for forming X-ray phase-contrast images of weakly absorbing (phase) objects. These include the crystal interferometer method, the Talbot interferometer method, diffraction-enhanced X-ray imaging, and the in-line method. The potential of their practical application in various fields of science and technology is discussed. The publications on the development and optimization of X-ray phase-contrast methods and the experimental study of phase objects are analyzed.

  11. Microfabrication of hard x-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik

    in the vertical and horizontal directions was addressed. A functioning prototype of a 2D silicon objective for use in a bright-field hard-XRM was demonstrated. The results are promising; showing acceptably low aberration and performance close to theoretical expectations. A resolution of 300 nm with 17 keV x...... rate larger than 10 pieces per hour indicates the economic value of injection molded x-ray lenses, which may have applications in more readily available small laboratory x-ray instruments or medical devices. In each case, observed non-uniformities of the shaped x-ray beams were investigated and found...

  12. 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.

  13. Radiation-induced thumbs carcinoma due to practicing dental X-ray

    Directory of Open Access Journals (Sweden)

    Esam S Halboub

    2015-01-01

    Full Text Available Dealing with diagnostic X-ray radiation may result in serious health problems, unless protection guidelines are followed. This became prevalent immediately a decade following the invention of X-ray radiation, where it had not been known that the accumulative exposure to X-ray radiation may carry huge health hazards. The reoccurrence of various fatal cancer cases compelled the concerned health authorities to develop safety standards to be followed by all X-ray clinics and technicians worldwide. This report documents the clinical case of a dental radiographer, who developed thumbs carcinoma after 15 years of practicing the profession, most likely due to his neglect of the X-ray radiation protection guidelines.

  14. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy.

    Science.gov (United States)

    Miaja-Avila, L; O'Neil, G C; Uhlig, J; Cromer, C L; Dowell, M L; Jimenez, R; Hoover, A S; Silverman, K L; Ullom, J N

    2015-03-01

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼10(6) photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >10(7) laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  15. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    Directory of Open Access Journals (Sweden)

    L. Miaja-Avila

    2015-03-01

    Full Text Available We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  16. X-ray diffraction contrast tomography (DCT) system, and an X-ray diffraction contrast tomography (DCT) method

    DEFF Research Database (Denmark)

    2012-01-01

    Source: US2012008736A An X-ray diffraction contrast tomography system (DCT) comprising a laboratory X-ray source (2), a staging device (5) rotating a polycrystalline material sample in the direct path of the X-ray beam, a first X-ray detector (6) detecting the direct X-ray beam being transmitted...

  17. Future X-ray timing missions

    CERN Document Server

    Barret, D; Staubert, R; Stella, L

    2000-01-01

    Thanks to the Rossi X-ray Timing Explorer (RXTE), it is now widely recognized that fast X-ray timing can be used to probe strong gravity fields around collapsed objects and constrain the equation of state of dense matter in neutron stars. We first discuss some of the outstanding issues which could be solved with an X-ray timing mission building on the great successes of RXTE and providing an order of magnitude better sensitivity. Then we briefly describe the 'Experiment for X-ray timing and Relativistic Astrophysics' (EXTRA) recently proposed to the European Space Agency as a follow-up to RXTE and the related US mission 'Relativistic Astrophysics Explorer' (RAE).

  18. Future X-Ray Timing Missions

    Science.gov (United States)

    Barret, Didier; van der Klis, Michiel; Skinner, Gerry K.; Staubert, Rüdiger; Stella, Luigi

    Thanks to the Rossi X-ray Timing Explorer (RXTE), it is now widely recognized that fast X-ray timing can be used to probe strong gravity fields around collapsed objects and constrain the equation of state of dense matter in neutron stars. We first discuss some of the outstanding issues which could be solved with an X-ray timing mission building on the great successes of RXTE and providing an order of magnitude better sensitivity. Then we briefly describe the `Experiment for X-ray timing and Relativistic Astrophysics' (EXTRA) recently proposed to the European Space Agency as a follow-up to RXTE and the related US mission `Relativistic Astrophysics Explorer' (RAE).

  19. Experimental x-ray ghost imaging

    CERN Document Server

    Pelliccia, Daniele; Scheel, Mario; Cantelli, Valentina; Paganin, David M

    2016-01-01

    We report an experimental proof of principle for ghost imaging in the hard x-ray energy range. We used a synchrotron x-ray beam that was split using a thin crystal in Laue diffraction geometry. With an ultra-fast imaging camera, we were able to image x-rays generated by isolated electron bunches. At this time scale, the shot noise of the synchrotron emission process is measurable as speckles, leading to speckle correlation between the two beams. The integrated transmitted intensity from a sample located in the first beam was correlated with the spatially resolved intensity measured on the second, empty, beam to retrieve the shadow of the sample. The demonstration of ghost imaging with hard x-rays may open the way to protocols to reduce radiation damage in medical imaging and in non-destructive structural characterization using Free Electron Lasers.

  20. Experimental X-Ray Ghost Imaging

    Science.gov (United States)

    Pelliccia, Daniele; Rack, Alexander; Scheel, Mario; Cantelli, Valentina; Paganin, David M.

    2016-09-01

    We report an experimental proof of principle for ghost imaging in the hard-x-ray energy range. We use a synchrotron x-ray beam that is split using a thin crystal in Laue diffraction geometry. With an ultrafast imaging camera, we are able to image x rays generated by isolated electron bunches. At this time scale, the shot noise of the synchrotron emission process is measurable as speckles, leading to speckle correlation between the two beams. The integrated transmitted intensity from a sample located in the first beam is correlated with the spatially resolved intensity measured in the second, empty, beam to retrieve the shadow of the sample. The demonstration of ghost imaging with hard x rays may open the way to protocols to reduce radiation damage in medical imaging and in nondestructive structural characterization using free electron lasers.

  1. Center for X-ray Optics (CXRO)

    Data.gov (United States)

    Federal Laboratory Consortium — The Center for X-Ray Optics at Lawrence Berkeley National Laboratory works to further science and technology using short wavelength optical systems and techniques....

  2. Why Do I Need X-Rays?

    Science.gov (United States)

    ... information you need from the Academy of General Dentistry Wednesday, August 24, 2016 About | Contact InfoBites Quick ... Related Articles: X-Rays The Academy of General Dentistry (AGD) Sets the Record Straight on Dental X- ...

  3. X-Ray Technologist Listing In California

    Data.gov (United States)

    U.S. Department of Health & Human Services — This table represents a current listing of X-Ray Technologists who are licensed by Radiologic Health Branch (RHB) of the California Department of Public Health. RHB...

  4. X-ray source for mammography

    Science.gov (United States)

    Logan, Clinton M.

    1994-01-01

    An x-ray source utilizing anode material which shifts the output spectrum to higher energy and thereby obtains higher penetrating ability for screening mammography application, than the currently utilized anode material. The currently used anode material (molybdenum) produces an energy x-ray spectrum of 17.5/19.6 keV, which using the anode material of this invention (e.g. silver, rhodium, and tungsten) the x-ray spectrum would be in the 20-35 keV region. Thus, the anode material of this invention provides for imaging of breasts with higher than average x-ray opacity without increase of the radiation dose, and thus reduces the risk of induced breast cancer due to the radiation dose administered for mammograms.

  5. 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 ...

  6. Chest X-Ray (Chest Radiography)

    Science.gov (United States)

    ... Lung tissue absorbs little radiation and will appear dark on the image. Until recently, x-ray images ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  7. X-ray microtomography in biology

    CERN Document Server

    Mizutani, Ryuta

    2016-01-01

    Progress in high-resolution x-ray microtomography has provided us with a practical approach to determining three-dimensional (3D) structures of opaque samples at micrometer to submicrometer resolution. In this review, we give an introduction to hard x-ray microtomography and its application to the visualization of 3D structures of biological soft tissues. Practical aspects of sample preparation, handling, data collection, 3D reconstruction, and structure analysis are described. Furthermore, different sample contrasting methods are approached in detail. Examples of microtomographic studies are overviewed to present an outline of biological applications of x-ray microtomography. We also provide perspectives of biological microtomography as the convergence of sciences in x-ray optics, biology, and structural analysis.

  8. X-ray imaging: Status and trends

    International Nuclear Information System (INIS)

    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

  9. 5.8 X-ray Calorimeters

    Science.gov (United States)

    Porter, F. Scott

    2008-01-01

    X-ray calorimeter instruments for astrophysics have seen rapid development since they were invented in 1984. The prime instrument on all currently planned X-ray spectroscopic observatories is based on calorimeter technology. This relatively simple detection concept that senses the energy of an incident photon by measuring the temperature rise of an absorber material at very low temperatures, can form the basis of a very high performance, non-dispersive spectrometer. State-of-the-art calorimeter instruments have resolving powers of over 3000, large simultaneous band-passes, and near unit efficiency. This coupled with the intrinsic imaging capability of a pixilated x-ray calorimeter array, allows true spectral-spatial instruments to be constructed. In this chapter I briefly review the detection scheme, the state-of-the-art in X-ray calorimeter instruments and the future outlook for this technology.

  10. Silicon Wafer X-ray Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this one year research project, we propose to do the following four tasks; (1) Design the silicon wafer X-ray mirror demo unit and develop a ray-tracing code to...

  11. Silicon Wafer X-ray Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this one year research project, we propose to do the following four tasks;(1) Design the silicon wafer X-ray mirror demo unit and develop a ray-tracing code to...

  12. Dental x-ray diagnostic installation

    International Nuclear Information System (INIS)

    An exemplary embodiment comprises an exposure unit including an X-ray tube and a cassette holder rotatable about vertical axes and between which the head of the patient is disposed. A radiation detector is disposed at the cassette holder for supplying an electrical signal corresponding to the dose rate when it is struck by X-rays and being interconnected with an X-ray tube voltage controller and a dose rate regulator in such manner that the X-ray tube voltage is influenced by the output of the radiation detector to control the dose rate to a value producing an optimum film blackening. A function generator determining the speed of the exposure unit is provided in which a speed curve is stored given which the radiation dose influencing the film is approximately constant

  13. Demonstration of X-ray talbot interferometry

    CERN Document Server

    Momose, A; Kawamoto, S; Hamaishi, Y; Takai, K; Suzuki, Y

    2003-01-01

    First Talbot interferometry in the hard X-ray region was demonstrated using a pair of transmission gratings made by forming gold stripes on glass plates. By aligning the gratings on the optical axis of X-rays with a separation that caused the Talbot effect by the first grating, moire fringes were produced inclining one grating slightly against the other around the optical axis. A phase object placed in front of the first grating was detected by moire-fringe bending. Using the technique of phase-shifting interferometry, the differential phase corresponding to the phase object could also be measured. This result suggests that X-ray Talbot interferometry is a novel and simple method for phase-sensitive X-ray radiography. (author)

  14. Resonant X-Ray Scattering and Absorption

    Science.gov (United States)

    Collins, S. P.; Bombardi, A.

    This chapter outlines some of the basic ideas behind nonresonant and resonant X-ray scattering, using classical or semiclassical pictures wherever possible; specifically, we highlight symmetry arguments governing the observation of X-ray optical effects, such as X-ray magnetic circular dichroism and resonant "forbidden" diffraction. Without dwelling on the microscopic physics that underlies resonant scattering, we outline some key steps required for calculating its rotation and polarization dependence, based on Cartesian and spherical tensor frameworks. Several examples of resonant scattering, involving electronic anisotropy and magnetism, are given as illustrations. Our goal is not to develop or defend theoretical concepts in X-ray scattering, but to bring together existing ideas in a pragmatic and utilitarian manner.

  15. Nonrelativistic quantum X-ray physics

    CERN Document Server

    Hau-Riege, Stefan P

    2015-01-01

    Providing a solid theoretical background in photon-matter interaction, Nonrelativistic Quantum X-Ray Physics enables readers to understand experiments performed at XFEL-facilities and x-ray synchrotrons. As a result, after reading this book, scientists and students will be able to outline and perform calculations of some important x-ray-matter interaction processes. Key features of the contents are that the scope reaches beyond the dipole approximation when necessary and that it includes short-pulse interactions. To aid the reader in this transition, some relevant examples are discussed in detail, while non-relativistic quantum electrodynamics help readers to obtain an in-depth understanding of the formalisms and processes. The text presupposes a basic (undergraduate-level) understanding of mechanics, electrodynamics, and quantum mechanics. However, more specialized concepts in these fields are introduced and the reader is directed to appropriate references. While primarily benefiting users of x-ray light-sou...

  16. Astrophysics: Unexpected X-ray flares

    Science.gov (United States)

    Campana, Sergio

    2016-10-01

    Two sources of highly energetic flares have been discovered in archival X-ray data of 70 nearby galaxies. These flares have an undetermined origin and might represent previously unknown astrophysical phenomena. See Letter p.356

  17. X-ray crystallographic studies of metalloproteins.

    Science.gov (United States)

    Volbeda, Anne

    2014-01-01

    Many proteins require metals for their physiological function. In combination with spectroscopic characterizations, X-ray crystallography is a very powerful method to correlate the function of protein-bound metal sites with their structure. Due to their special X-ray scattering properties, specific metals may be located in metalloprotein structures and eventually used for phasing the diffracted X-rays by the method of Multi-wavelength Anomalous Dispersion (MAD). How this is done is the principle subject of this chapter. Attention is also given to the crystallographic characterization of different oxidation states of redox active metals and to the complication of structural changes that may be induced by X-ray irradiation of protein crystals.

  18. Demonstration of X-ray talbot interferometry

    International Nuclear Information System (INIS)

    First Talbot interferometry in the hard X-ray region was demonstrated using a pair of transmission gratings made by forming gold stripes on glass plates. By aligning the gratings on the optical axis of X-rays with a separation that caused the Talbot effect by the first grating, moire fringes were produced inclining one grating slightly against the other around the optical axis. A phase object placed in front of the first grating was detected by moire-fringe bending. Using the technique of phase-shifting interferometry, the differential phase corresponding to the phase object could also be measured. This result suggests that X-ray Talbot interferometry is a novel and simple method for phase-sensitive X-ray radiography. (author)

  19. X-ray Emission from Solar Flares

    Indian Academy of Sciences (India)

    Rajmal Jain; Malini Aggarwal; Raghunandan Sharma

    2008-03-01

    Solar X-ray Spectrometer (SOXS), the first space-borne solar astronomy experiment of India was designed to improve our current understanding of X-ray emission from the Sun in general and solar flares in particular. SOXS mission is composed of two solid state detectors, viz., Si and CZT semiconductors capable of observing the full disk Sun in X-ray energy range of 4–56 keV. The X-ray spectra of solar flares obtained by the Si detector in the 4–25 keV range show evidence of Fe and Fe/Ni line emission and multi-thermal plasma. The evolution of the break energy point that separates the thermal and non-thermal processes reveals increase with increasing flare plasma temperature. Small scale flare activities observed by both the detectors are found to be suitable to heat the active region corona; however their location appears to be in the transition region.

  20. Inelastic magnetic X-ray scattering

    Science.gov (United States)

    Platzman, P. M.; Tzoar, N.

    1985-04-01

    The theory of magnetic X-ray scattering is used to discuss the possibilities for employing inelastic scattering to probe the magnetic properties of condensed matter systems. In particular, it is shown how the interference between the nonmagnetic (Compton) and magnetic scattering arising from the use of circularly polarized X-rays is absolutely essential in such experiments. The very beautiful preliminary experiments by Sakai and Ono (1976) on Fe which use circularly polarized Moessbauer gamma-rays will be discussed. They already show the sensitivity of the technique to the 'magnetic form factor'. In addition, the physics of a unique quarter wave plate employed in obtaining circularly polarized X-rays is considered, and the implications of this advance for doing such experiments on existing synchrotron X-ray sources are discussed.

  1. Capillary Optics generate stronger X-rays

    Science.gov (United States)

    1996-01-01

    NASA scientist, in the Space Sciences lab at Marshall, works with capillary optics that generate more intense X-rays than conventional sources. This capability is useful in studying the structure of important proteins.

  2. Insights from soft X-rays

    DEFF Research Database (Denmark)

    Raaf, Jennifer; Issinger, Olaf-Georg; Niefind, Karsten

    2008-01-01

    The diffraction pattern of a protein crystal is normally a product of the interference of electromagnetic waves scattered by electrons of the crystalline sample. The diffraction pattern undergoes systematic changes in case additionally X-ray absorption occurs, meaning if the wavelength of the pri......The diffraction pattern of a protein crystal is normally a product of the interference of electromagnetic waves scattered by electrons of the crystalline sample. The diffraction pattern undergoes systematic changes in case additionally X-ray absorption occurs, meaning if the wavelength...... of the primary X-ray beam is relatively close to the absorption edge of selected elements of the sample. The resulting effects are summarized as "anomalous dispersion" and can be always observed with "soft" X-rays (wavelength around 2 A) since they match the absorption edges of sulfur and chlorine...

  3. Dentistry 4. X-ray diagnostics

    International Nuclear Information System (INIS)

    DIN pocketbook 267/4 gives an overview of the normative requirements of the new X-Ray and Radiation Protection Ordinance, which has been in effect since 1 November 2011. This DIN pocketbook is intended for anyone charged with professional responsibility for the use of ionizing radiation in dentistry, operators and users of x-ray devices, radiation protection officers, accredited experts, manufacturers as well as for anyone with an interest in radiation protection or optimal radiological diagnostics. It contains standards relating to the following areas: acceptance and constancy testing; devices for evaluating findings (monitors, film viewing devices), films, printers; archiving, designating, labelling. Adherence to the standards makes it possible to avoid distractive artefacts in x-ray images and optimise the quality of x-ray diagnostics in dentistry.

  4. Linking Jet Emission, X-Ray States, and Hard X-Ray Tails in the Neutron Star X-Ray Binary GX 17+2

    NARCIS (Netherlands)

    S. Migliari; J.C.A. Miller-Jones; R.P. Fender; J. Homan; T. di Salvo; R.E. Rothschild; M.P. Rupen; J.A. Tomsick; R. Wijnands; M. van der Klis

    2007-01-01

    We present the results of simultaneous radio (VLA) and X-ray (RXTE) observations of the Z-type neutron star X-ray binary GX 17+2. The aim is to assess the coupling between X-ray and radio properties throughout its three rapidly variable X-ray states and during the time-resolved transitions. These ob

  5. Advanced detectors for X-ray microscopy

    International Nuclear Information System (INIS)

    Over the last decade the advances in x-ray microscopy have mainly been due to the development of x-ray source technology and to the micro-fabrication of x-ray optics. These advances have spurred the development of x-ray microscopes that are approaching the best resolution possible in the presence of radiation damage in the specimen. In addition, the development of specimen preparation techniques that reduce tile effects of radiation damage on the specimen are underway. In contrast, tile development or x-ray detectors for x-ray microscopy has been a low priority. The objective of the work was to develop a new detector for x-ray microscopy. This involved the modification of a Thorn EMI electron tube in order to sensitise the multiplier for soil x-rays In the energy range of interest (0.2-6 keV). The electron multiplier was then tested on a repetitive laser plasma source, which has been shown to be eminently suitable for a laboratory scale x-ray microscope, and the Scanning Transmission X-ray Microscope (STXM) at the National Synchrotron Light Source (NSLS), which is the most successful STXM presently in operation. The processed data from tile electron multiplier was used to characterise its response and assess its potential as all alternative to existing detectors. In addition, ID21, the microscopy beamline at the European Synchrotron Radiation Source (ESRF) was studied to assess the need for a beam position monitor close to the exit slit of the monochromator. This involved the ray tracing of the beamline. It was proposed that in the case of a crystal monochromator a beam position monitor based oil the total signal from a photo-emitting blade containing a number of different diameter pinholes was sufficient. However, for a grating monochromator tile beamline design relied upon feedback from a beam position monitor capable of detecting the height of the beam at tile entrance to the microscope. A number of conceptual designs for a monitor that could fulfil this

  6. Principles of X-ray Navigation

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, John Eric; /SLAC

    2006-03-17

    X-ray navigation is a new concept in satellite navigation in which orientation, position and time are measured by observing stellar emissions in x-ray wavelengths. X-ray navigation offers the opportunity for a single instrument to be used to measure these parameters autonomously. Furthermore, this concept is not limited to missions in close proximity to the earth. X-ray navigation can be used on a variety of missions from satellites in low earth orbit to spacecraft on interplanetary missions. In 1997 the Unconventional Stellar Aspect Experiment (USA) will be launched as part of the Advanced Research and Global Observation Satellite (ARGOS). USA will provide the first platform for real-time experimentation in the field of x-ray navigation and also serves as an excellent case study for the design and manufacturing of space qualified systems in small, autonomous groups. Current techniques for determining the orientation of a satellite rely on observations of the earth, sun and stars in infrared, visible or ultraviolet wavelengths. It is possible to use x-ray imaging devices to provide arcsecond level measurement of attitude based on star patterns in the x-ray sky. This technique is explored with a simple simulation. Collimated x-ray detectors can be used on spinning satellites to provide a cheap and reliable measure of orientation. This is demonstrated using observations of the Crab Pulsar taken by the high Energy Astronomy Observatory (HEAO-1) in 1977. A single instrument concept is shown to be effective, but dependent on an a priori estimate of the guide star intensity and thus susceptible to errors in that estimate. A star scanner based on a differential measurement from two x-ray detectors eliminates the need for an a priori estimate of the guide star intensity. A first order model and a second order model of the two star scanner concepts are considered. Many of the stars that emit in the x-ray regime are also x-ray pulsars with frequency stability approaching a

  7. X-ray scattering from dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    McSherry, D.J

    2000-09-01

    Dense plasmas were studied by probing them with kilovolt x-rays and measuring those scattered at various angles. The Laser-Produced x-ray source emitted Ti He alpha 4.75 keV x-rays. Two different plasma types were explored. The first was created by laser driven shocks on either side of a sample foil consisting of 2 micron Al layer, sandwiched between two 1 micron CH layers. We have observed a peak in the x-ray scattering cross section, indicating diffraction from the plasma. However, the experimentally inferred plasma density, broadly speaking, did not always agree with the hydrodynamic simulation MEDX (A modified version of MEDUSA). The second plasma type that we studied was created by soft x-ray heating on either side of a sample foil, this time consisting of 1 micron layer of Al, sandwiched between two 0.2 micron CH layers. Two foil targets, each consisting of a 0.1 micron thick Au foil mounted on 1 micron of CH, where placed 4 mm from the sample foil. The soft x-rays where produced by laser irradiating these two foil targets. We found that, 0.5 ns after the peak of the laser heating pulses, the measured cross sections more closely matched those simulated using the Thomas Fermi model than the Inferno model. Later in time, at 2 ns, the plasma is approaching a weakly coupled state. This is the first time x-ray scattering cross sections have been measured from dense plasmas generated by radiatively heating both sides of the sample. Moreover, these are absolute values typically within a factor of two of expectation for early x-ray probe times. (author)

  8. X-ray laser program at MBI

    Science.gov (United States)

    Nickles, P. V.; Janulewicz, K. A.; Lucianetti, A.; Priebe, G.; Zigler, A.; Rocca, J. J.; Sandner, W.

    2002-11-01

    A survey of the Max Born Institute (MBI) activities in the field of X-ray lasers (XRLs) is presented. The main interest is focused on the transient soft X-ray lasers. Additionally, much work is put to look for new, efficient, compact (table-top) pumping schemes with a prospect to be applied in practice. The current state of the research and the plans for the future are described as well.

  9. Capacitor discharges, magnetohydrodynamics, X-rays, ultrasonics

    CERN Document Server

    Früngel, Frank B A

    1965-01-01

    High Speed Pulse Technology, Volume 1: Capacitor Discharges - Magnetohydrodynamics - X-Rays - Ultrasonics deals with the theoretical and engineering problems that arise in the capacitor discharge technique.This book discusses the characteristics of dielectric material, symmetrical switch tubes with mercury filling, and compensation conductor forms. The transformed discharge for highest current peaks, ignition transformer for internal combustion engines, and X-ray irradiation of subjects in mechanical motion are also elaborated. This text likewise covers the transformed capacitor discharge in w

  10. Supernova remnants: the X-ray perspective

    OpenAIRE

    Vink, Jacco

    2011-01-01

    Supernova remnants are beautiful astronomical objects that are also of high scientific interest, because they provide insights into supernova explosion mechanisms, and because they are the likely sources of Galactic cosmic rays. X-ray observations are an important means to study these objects.And in particular the advances made in X-ray imaging spectroscopy over the last two decades has greatly increased our knowledge about supernova remnants. It has made it possible to map the products of fr...

  11. Scattered X-ray beam nondestructive testing

    Science.gov (United States)

    Harding, G.; Kosanetzky, J.

    1989-08-01

    X-ray scatter interactions generally dominate the linear attenuation coefficient at the photon energies typical of medical and industrial radiography. Specific advantages of X-ray scatter imaging, including a flexible choice of measurement geometry, direct 3D-imaging capability (tomography) and improved information for material characterization, are illustrated with results from Compton and coherent scatter devices. Applications of a Compton backscatter scanner (ComScan) in the aerospace industry and coherent scatter imaging in security screening are briefly considered.

  12. Globular cluster x-ray sources.

    Science.gov (United States)

    Pooley, David

    2010-04-20

    Globular clusters and x-ray astronomy have a long and fruitful history. Uhuru and OSO-7 revealed highly luminous (> 10(36) ergs(-1)) x-ray sources in globular clusters, and Einstein and ROSAT revealed a larger population of low-luminosity (luminosity sources were low-mass x-ray binaries in outburst and that they were orders of magnitude more abundant per unit mass in globular clusters than in the rest of the galaxy. However, the low-luminosity sources proved difficult to classify. Many ideas were put forth--low-mass x-ray binaries in quiescence (qLMXBs), cataclysmic variables (CVs), active main-sequence binaries (ABs), and millisecond pulsars (MSPs)--but secure identifications were scarce. In ROSAT observations of 55 clusters, about 25 low-luminosity sources were found. Chandra has now observed over 80 Galactic globular clusters, and these observations have revealed over 1,500 x-ray sources. The superb angular resolution has allowed for many counterpart identifications, providing clues to the nature of this population. It is a heterogeneous mix of qLMXBs, CVs, ABs, and MSPs, and it has been shown that the qLMXBs and CVs are both, in part, overabundant like the luminous LMXBs. The number of x-ray sources in a cluster correlates very well with its encounter frequency. This points to dynamical formation scenarios for the x-ray sources and shows them to be excellent tracers of the complicated internal dynamics. The relation between the encounter frequency and the number of x-ray sources has been used to suggest that we have misunderstood the dynamical states of globular clusters.

  13. Globular cluster x-ray sources

    Science.gov (United States)

    Pooley, David

    2010-01-01

    Globular clusters and x-ray astronomy have a long and fruitful history. Uhuru and OSO-7 revealed highly luminous (> 1036 ergs-1) x-ray sources in globular clusters, and Einstein and ROSAT revealed a larger population of low-luminosity (luminosity sources were low-mass x-ray binaries in outburst and that they were orders of magnitude more abundant per unit mass in globular clusters than in the rest of the galaxy. However, the low-luminosity sources proved difficult to classify. Many ideas were put forth—low-mass x-ray binaries in quiescence (qLMXBs), cataclysmic variables (CVs), active main-sequence binaries (ABs), and millisecond pulsars (MSPs)—but secure identifications were scarce. In ROSAT observations of 55 clusters, about 25 low-luminosity sources were found. Chandra has now observed over 80 Galactic globular clusters, and these observations have revealed over 1,500 x-ray sources. The superb angular resolution has allowed for many counterpart identifications, providing clues to the nature of this population. It is a heterogeneous mix of qLMXBs, CVs, ABs, and MSPs, and it has been shown that the qLMXBs and CVs are both, in part, overabundant like the luminous LMXBs. The number of x-ray sources in a cluster correlates very well with its encounter frequency. This points to dynamical formation scenarios for the x-ray sources and shows them to be excellent tracers of the complicated internal dynamics. The relation between the encounter frequency and the number of x-ray sources has been used to suggest that we have misunderstood the dynamical states of globular clusters. PMID:20404204

  14. Parametric X-rays at FAST

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Tanaji [Fermilab

    2016-06-01

    We discuss the generation of parametric X-rays (PXR) in the photoinjector at the new FAST facility at Fermilab. Detailed calculations of the intensity spectrum, energy and angular widths and spectral brilliance with a diamond crystal are presented. We also report on expected results with PXR generated while the beam is channeling. The low emittance electron beam makes this facility a promising source for creating brilliant X-rays.

  15. Detection limits in x-ray fluorescence analysis

    International Nuclear Information System (INIS)

    X-ray fluorescence spectrometry is a well established analytical technique for elemental analysis of solids, powders, or liquids. This extended abstract briefly discusses the detection limits or sensitivity of x-ray spectrometers in x-ray fluorescence analysis

  16. Optics Developments for X-Ray Astronomy

    Science.gov (United States)

    Ramsey, Brian

    2014-01-01

    X-ray optics has revolutionized x-ray astronomy. The degree of background suppression that these afford, have led to a tremendous increase in sensitivity. The current Chandra observatory has the same collecting area (approx. 10(exp 3)sq cm) as the non-imaging UHURU observatory, the first x-ray observatory which launched in 1970, but has 5 orders of magnitude more sensitivity due to its focusing optics. In addition, its 0.5 arcsec angular resolution has revealed a wealth of structure in many cosmic x-ray sources. The Chandra observatory achieved its resolution by using relatively thick pieces of Zerodur glass, which were meticulously figured and polished to form the four-shell nested array. The resulting optical assembly weighed around 1600 kg, and cost approximately $0.5B. The challenge for future x-ray astronomy missions is to greatly increase the collecting area (by one or more orders of magnitude) while maintaining high angular resolution, and all within realistic mass and budget constraints. A review of the current status of US optics for x-ray astronomy will be provided along with the challenges for future developments.

  17. Coherence in X-ray physics.

    Science.gov (United States)

    Lengeler, B

    2001-06-01

    Highly brilliant synchrotron radiation sources have opened up the possibility of using coherent X-rays in spectroscopy and imaging. Coherent X-rays are characterized by a large lateral coherence length. Speckle spectroscopy is extended to hard X-rays, improving the resolution to the nm range. It has become possible to image opaque objects in phase contrast with a sensitivity far superior to imaging in absorption contrast. All the currently available X-ray sources are chaotic sources. Their characterization in terms of coherence functions of the first and second order is introduced. The concept of coherence volume, defined in quantum optics terms, is generalized for scattering experiments. When the illuminated sample volume is smaller than the coherence volume, the individuality of the defect arrangement in a sample shows up as speckle in the scattered intensity. Otherwise, a configurational average washes out the speckle and only diffuse scattering and possibly Bragg reflections will survive. The loss of interference due to the finite detection time, to the finite detector pixel size and to uncontrolled degrees of freedom in the sample is discussed at length. A comparison between X-ray scattering, neutron scattering and mesoscopic electron transport is given. A few examples illustrate the possibilities of coherent X-rays for imaging and intensity correlation spectroscopy.

  18. Elliptical X-Ray Spot Measurement

    CERN Document Server

    Richardson, R A; Weir, J T; Richardson, Roger A.; Sampayan, Stephen; Weir, John T.

    2000-01-01

    The so-called roll bar measurement uses a heavy metal material, optically thick to x-rays, to form a shadow of the x-ray origination spot. This spot is where an energetic electron beam interacts with a high Z target. The material (the "roll bar") is slightly curved to avoid alignment problems. The roll bar is constructed and positioned so that the x-rays are shadowed in the horizontal and vertical directions, so information is obtained in two dimensions. If a beam profile is assumed (or measured by other means), the equivalent x-ray spot size can be calculated from the x-ray shadow cast by the roll bar. Thus the ellipticity of the beam can be calculated, assuming the ellipse of the x-ray spot is aligned with the roll bar. The data is recorded using a scintillator and gated camera. Data will be presented from measurements using the ETA II induction LINAC. The accuracy of the measurement is checked using small elliptical targets.

  19. Echoes in X-ray Binaries

    CERN Document Server

    O'Brien, K; Hynes, R; Chen, W; Haswell, C; Still, M

    2002-01-01

    We present a method of analysing the correlated X-ray and optical/UV variability in X-ray binaries, using the observed time delays between the X-ray driving lightcurves and their reprocessed optical echoes. This allows us to determine the distribution of reprocessing sites within the binary. We model the time-delay transfer functions by simulating the distribution of reprocessing regions, using geometrical and binary parameters. We construct best-fit time-delay transfer functions, showing the regions in the binary responsible for the reprocessing of X-rays. We have applied this model to observations of the Soft X-ray Transient, GRO j1655-40. We find the optical variability lags the X-ray variability with a mean time delay of 19.3$pm{2.2}$ seconds. This means that the outer regions of the accretion disc are the dominant reprocessing site in this system. On fitting the data to a simple geometric model, we derive a best-fit disk half-opening angle of 13.5$^{+2.1}_{-2.8}$ degrees, which is similar to that observe...

  20. A million X-ray detections

    Science.gov (United States)

    Webb, N.; XMM-Newton Survey Science Centre (SSC)

    2016-06-01

    Part of the XMM-Newton Survey Science Centre responsibilities include producing an X-ray catalogue of all X-ray sources detected with XMM-Newton. The latest version, 3XMM, takes advantage of improvements made to the source characterisation, reducing the number of spurious detections, but providing better astrometric precision, greater net sensitivity, as well as spectra and timeseries for a quarter of all catalogue detections. The data release 5 (3XMM-DR5, April 2015) is derived from the first 13 years of observations with XMM-Newton. 3XMM-DR5 includes 565962 X-ray detections and 396910 unique sources, detected as many as 48 times. 3XMM-DR5 is therefore the largest X-ray source catalogue. 3XMM-DR6 will be made available during 2016 and will augment the catalogue with 70000 X-ray detections. Over the next decade the catalogue will reach 1 million X-ray detections, including galaxy clusters, galaxies, tidal disruption events, gamma-ray bursts, stars, stellar mass compact objects, supernovae, planets, comets and many other systems. Thanks to the wide range of data products for each catalogue detection, the catalogue is an excellent resource for finding populations of sources as well as new and extreme objects. Here we present results achieved from searching the catalogue and discuss improvements that will be provided in future versions.

  1. X-ray Emission of Hollow Atoms

    Institute of Scientific and Technical Information of China (English)

    ZhaoYongtao; XiaoGuoqing; ZhangXiaoan; YangZhihu; ChenXimeng; ZhangYanping

    2003-01-01

    We have systematically investigated the X-rays emission of hollow atoms (HA) which formed in the interaction of highly charged ions with a variety of solid surfaces at the atomic physics experimental setup of IMP. The X-ray spectra were measured by Si(Li) detectors with effective energy ranging from 1 keV to 60 keV. The results show that, the X-ray emission from the formed HA is closely correlated with the charge state of the projectile ions, and weakly correlated with the velocity of the projectile ions. For example, it was found that when Ar18+ ions interact with Be-target, the yield of K X-ray with character energy of 3.0 keV is 7.2×10-3 per ion, which is two times and 5 order of magnitude higher than those in the interactions of Ar17+ and Ar16+ ions respectively. When Ar15+ ions interact with the same targets, the Argon K X-ray would be too feeble to be detected. The X-ray yield with single ion in this experiment can be represented by the following equation,

  2. Low exposure x-ray transmission measurements for contrast media detection with filtered x-rays

    International Nuclear Information System (INIS)

    A feasibility study of X-ray transmission measurements for contrast media with less exposure using filtered X-rays and their energy information is described. Based on measurements of the energy spectra of La-filtered X-rays, sensitivity to the contrast media and the relative quantity of dose exposure of filtered X-rays as the ratio to white X-rays are shown. The dose exposure for the measurement of iodine contrast media is reduced by more than 50% with a 400 μm thick La filter. By using a filter with atomic number close to that of iodine such as Cs and Ba, a greater reduction in dose exposure with a smaller increase in the current of the X-ray tube is expected. (author)

  3. Megavoltage CT on a tomotherapy system

    International Nuclear Information System (INIS)

    A megavoltage computed tomography (MVCT) system was developed on the University of Wisconsin tomotherapy benchtop. This system can operate either axially or helically, and collect transmission data without any bounds on delivered dose. Scan times as low as 12 s per slice are possible, and scans were run with linac output rates of 100 MU min-1, although the system can be tuned to deliver arbitrarily low dose rates. Images were reconstructed with clinically reasonable doses ranging from 8 to 12 cGy. These images delineate contrasts below 2% and resolutions of 3.0 mm. Thus, the MVCT image quality of this system should be sufficient for verifying the patient's position and anatomy prior to radiotherapy. Additionally, synthetic data were used to test the potential for improved MVCT contrast using maximum-likelihood (ML) reconstruction. Specifically, the maximum-likelihood expectation-maximization (ML-EM) algorithm and a transmission ML algorithm were compared with filtered backprojection (FBP). It was found that for expected clinical MVCT doses enough imaging photons are used such that little benefit is conferred by the improved noise model of ML algorithms. For significantly lower doses, some quantitative improvement is achieved through ML reconstruction. Nonetheless, the image quality at those lower doses is not satisfactory for radiotherapy verification. (author)

  4. Distribution of X-ray examinations within the Danish population

    International Nuclear Information System (INIS)

    Full text: Medical X-ray exposures are the largest source of man-made exposure to ionising radiation in developed countries. Therefore, there is an interest to determine the population dose from medical X-rays, for the population as a whole as well as for selected groups, for instance for different age groups. In order to determine these quantities, knowledge of the frequency of X-ray examinations for different age groups is needed. In Denmark, 95% of all hospitals are public, and more than 95% of all procedures in hospitals are carried out in the public hospitals. Dental X-ray procedures are frequent but contribute very little to the population dose. Excluding dental procedures, only a limited number of X-ray procedures (estimated to be around 5% of the total number) are carried out in private clinics outside the hospitals. To assess the frequencies of X-ray procedures, it is therefore a good approximation to assess only the frequencies of procedures carried out in public hospitals. All of these procedures are registered in a national database. The data stored includes a unique identifier for each patient, sex and year of birth of the patient and the name of the procedure. In addition, data on the age and sex distribution of the population is available from national registers. Due to the presence of the unique identifiers, it is possible to assess not only the total number of examinations carried out, but also the number of examinations for each patient. In 2004, 18% of the population underwent one or more X-ray examinations, with the number of examinations varying from 1 to 101. There are marked differences between the different age groups; with frequencies ranging from 7% for the group of 0 - 4 year olds to 45% for 90+ years. Among the persons examined, more than 50% undergo more than examination, while 9% undergo more than five examinations. The types of examinations also vary considerably for different age groups. E.g., CT examinations constitute 2% of all

  5. Clinical value of MRI combined with X-ray in diagnosis of wrist joint instability%MRI联合X线诊断腕关节不稳定的临床价值

    Institute of Scientific and Technical Information of China (English)

    吴伟智; 张家雄; 陈兴明; 朱冬梅; 梁培生

    2016-01-01

    目的 探讨MRI联合X线诊断腕关节不稳定的临床价值.方法 选择我院2013年8月至2014年6月腕关节不稳定患者100例,根据入院先后顺序分为观察组和对照组,每组50例,观察组进行MRI联合X线诊断检查,对照组仅进行X线检查,分析各组的影像学特征并比较两组的特异性、灵敏性、阳性预测值等临床指标.结果 对照组的阳性检出率为56.0%(28/50),明显低于观察组的88.0%(44/50),差异具有统计学意义(P<0.05);观察组的阳性预测值为86.0%(43/50)、特异性为88.0%(44/50)、灵敏性为80%(40/50),对照组的阳性预测值为46.0%(23/50)、特异性为56.0%(28/50)、灵敏性为42.0%(21/50),观察组的阳性预测值、特异性、灵敏性等指标显著优于对照组,差异具有统计学意义(P<0.05);腕骨病变MRI检查结果中,T1WI轴位像:掌指关节周围滑膜显著增厚,信号减低,呈长或稍长T1信号改变;T1WI冠状位:近端指间关节、掌指关节及双侧腕关节周围滑膜增厚,呈等或稍长T1信号;STIR冠状位像:病灶呈高或稍高信号,病灶部位、形态、范围较T2WI、T1WI像显示更清晰,指骨近端及腕关节、双侧掌骨远端构成骨信号增高,提示骨髓水肿.结论 腕关节不稳定进行MRI与X线联合诊断可提高其检测的特异性、灵敏性,提高其阳性诊断率.%Objective To discuss the clinical value of magnetic resonance imaging (MRI) combined with X-ray in diagnosis of wrist joint instability. Methods One hundred patients with wrist joint instability from August 2013 to June 2014 were selected in our hospital, which were divided into the study group and the control group, accord-ing to the order of admission. The study group (n=50) underwent MRI combined with X-ray examination, while the con-trol group was only performed X-ray examination. The imaging characteristics of each group were analyzed, and the specificity, sensitivity and positive predictive value of the two groups were

  6. X-ray imaging in advanced studies of ophthalmic diseases.

    Science.gov (United States)

    Antunes, Andrea; Safatle, Angélica M V; Barros, Paulo S M; Morelhão, Sérgio L

    2006-07-01

    Microscopic characterization of pathological tissues has one major intrinsic limitation, the small sampling areas with respect to the extension of the tissues. Mapping possible changes on vast tissues and correlating them with large ensembles of clinical cases is not a feasible procedure for studying most diseases, as for instance vision loss related diseases and, in particular, the cataract. Although intraocular lens implants are successful treatments, cataract still is a leading public-health issue that grows in importance as the population increases and life expectancy is extended worldwide. In this work we have exploited the radiation-tissue interaction properties of hard x-rays--very low absorption and scattering--to map distinct lesions on entire eye lenses. At the used synchrotron x-ray photon energy of 20 keV (wavelength lambda=0.062 nm), scattering and refraction are angular resolved effects. It allows the employed x-ray image technique to efficiently characterize two types of lesions in eye lenses under cataractogenesis: distributions of tiny scattering centers and extended areas of fiber cell compaction. The data collection procedure is relatively fast; allowing dozens of samples to be totally imaged (scattering, refraction, and mass absorption images) in a single day of synchrotron beam time. More than 60 cases of canine cataract, not correlated to specific causes, were investigated in this first application of x-rays to image entire lenses. Cortical opacity cases, or partial opacity, could be related to the presence of calcificated tissues at the cortical areas, clearly visible in the images, whose elemental contents were verified by micro x-ray fluorescence as very rich in calcium. Calcificated tissues were also observed at nuclear areas in some cases of hypermature cataract. Total opacity cases without distinguishable amount of scattering centers consist in 70% of the analyzed cases, where remarkable fissure marks owing to extended areas of fiber

  7. Effects of x-ray does on rhizosphere studies using x-ray computed tomography

    OpenAIRE

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

    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 ...

  8. Simulation of transmitted X-rays in a polycapillary X-ray lens

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Shiqi [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Liu, Zhiguo, E-mail: liuzhiguo512@126.com [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Sun, Tianxi; Wang, Kai; Yi, Longtao; Yang, Kui; Chen, Man; Wang, Jinbang [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China)

    2015-09-21

    The geometrical description of capillary systems adjusted for the controlled guiding of X-rays and the basic theory of the transmission of X-rays are presented. A method of numerical calculation, based on Ray-Tracing theory, is developed to simulate the transmission efficiency of an X-ray parallel lens and the shape and size of the light spot gain from it. The simulation results for two half-lenses are in good agreement with the experimental results.

  9. Simulation of transmitted X-rays in a polycapillary X-ray lens

    International Nuclear Information System (INIS)

    The geometrical description of capillary systems adjusted for the controlled guiding of X-rays and the basic theory of the transmission of X-rays are presented. A method of numerical calculation, based on Ray-Tracing theory, is developed to simulate the transmission efficiency of an X-ray parallel lens and the shape and size of the light spot gain from it. The simulation results for two half-lenses are in good agreement with the experimental results

  10. Comparison of x-ray output of inverter-type x-ray equipment

    International Nuclear Information System (INIS)

    The x-ray output of 54 inverter-type x-ray apparatuses used at 18 institutions was investigated. The reproducibility and linearity of x-ray output and variations among the x-ray equipment were evaluated using the same fluorescence meter. In addition, the x-ray apparatuses were re-measured using the same non-invasive instrument to check for variations in tube voltage, tube current, and irradiation time. The non-invasive instrument was calibrated by simultaneously obtaining measurements with an invasive instrument, employing the tube voltage and current used for the invasive instrument, and the difference was calculated. Reproducibility of x-ray output was satisfactory for all x-ray apparatuses. The coefficient of variation was 0.04 or less for irradiation times of 5 ms or longer. In 84.3% of all x-ray equipment, variation in the linearity of x-ray output was 15% or less for an irradiation time of 5 ms. However, for all the apparatuses, the figure was 50% when irradiation time was the shortest (1 to 3 ms). Variation in x-ray output increased as irradiation time decreased. Variation in x-ray output ranged between 1.8 and 2.5 compared with the maximum and minimum values, excluding those obtained at the shortest irradiation time. The relative standard deviation ranged from ±15.5% to ±21.0%. The largest variation in x-ray output was confirmed in regions irradiated for the shortest time, with smaller variations observed for longer irradiation times. The major factor responsible for variation in x-ray output in regions irradiated for 10 ms or longer, which is a relatively long irradiation time, was variation in tube current. Variation in tube current was slightly greater than 30% at maximum, with an average value of 7% compared with the preset tube current. Variations in x-ray output in regions irradiated for the shortest time were due to photographic effects related to the rise and fall times of the tube voltage waveform. Accordingly, in order to obtain constant x-ray

  11. Laser-based X-ray and electron source for X-ray fluorescence studies

    Science.gov (United States)

    Valle Brozas, F.; Crego, A.; Roso, L.; Peralta Conde, A.

    2016-08-01

    In this work, we present a modification to conventional X-rays fluorescence using electrons as excitation source and compare it with the traditional X-ray excitation for the study of pigments. For this purpose, we have constructed a laser-based source capable to produce X-rays as well as electrons. Because of the large penetration depth of X-rays, the collected fluorescence signal is a combination of several material layers of the artwork under study. However, electrons are stopped in the first layers, allowing a more superficial analysis. We show that the combination of both excitation sources can provide extremely valuable information about the structure of the artwork.

  12. Fabrication of large area X-ray diffraction grating for X-ray phase imaging

    International Nuclear Information System (INIS)

    X-ray lithography, which uses highly directional synchrotron radiation, is one of the technologies that can be used for fabricating micrometer-sized structures. In X-ray lithography, the accuracy of the fabricated structure depends largely on the accuracy of the X-ray mask. Since X-ray radiation is highly directional, a micro-fabrication technology that produces un-tapered and high aspect ratio highly absorbent structures on a low absorbent membrane is required. Conventionally, a resin material is used as the support membrane for large area X-ray masks. However, resin membranes have the disadvantage that they can sag after several cycles of X-ray exposure due to the heat generated by the X-rays. Therefore, we proposed and used thin carbon wafers for the membrane material because carbon has an extremely small thermal expansion coefficient. We fabricated new carbon membrane X-ray masks, and these results of X-ray lithography demonstrate the superior performance.

  13. Tumour visualisation in human soft tissue using grating-based X-ray phase contrast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Herzen, Julia; Willner, Marian; Schleede, Simone; Bech, Martin; Tapfer, Arne; Stockmar, Marco; Achterhold, Klaus; Pfeiffer, Franz [Department of Physics (E17) and Institute of Medical Engineering (IMETUM), Technische Universitaet Muenchen (Germany)

    2011-07-01

    The grating-based phase-contrast imaging provides enhanced image structure details, which are partly complementary or even not attainable with standard X-ray absorption imaging. Especially in the case of biological soft tissue when standard x-ray radiography is often limited due to the weak absorption contrast, this method represents a real alternative. Based on X-ray optical transmission gratings this modality has transferred the phase-contrast imaging from the highly brilliant synchrotron radiation sources to conventional laboratory-based broadband x-ray tubes. Here, we present a study on human soft tissue specimens containing tumours using the grating-based phase contrast imaging at both highly brilliant synchrotron (ESRF, Grenoble), and at conventional X-ray laboratory radiation sources. Our results demonstrate a superior contrast for different kinds of soft tissue in the phase contrast and verify this imaging modality to be a promising candidate to establish phase-contrast imaging in clinical radiology.

  14. Design of a novel phase contrast X-ray imaging system for mammography

    International Nuclear Information System (INIS)

    X-ray phase contrast imaging is a very promising technique which may lead to significant advancements in medical imaging. One of the impediments to the clinical implementation of the technique is the general requirement to have an X-ray source of high coherence. The radiation physics group at UCL is currently developing an X-ray phase contrast imaging technique which works with laboratory X-ray sources. The design of this system requires rigorous simulation of the imaging system and the interaction of X-rays with healthy and unhealthy breast tissue. We present in this paper the results of such simulations showing the expected gain in contrast arising from the proposed system and the system's initial design.

  15. Long Bone X-ray Image Stitching Using C-arm Motion Estimation

    Science.gov (United States)

    Wang, Lejing; Traub, Joerg; Heining, Sandro Michael; Benhimane, Selim; Euler, Ekkehard; Graumann, Rainer; Navab, Nassir

    In this paper, we propose a novel method to generate panoramic X-ray images intra-operatively by using the previously introduced camera augmented mobile C-arm by Navab et al. [1]. This advanced mobile C-arm system acquires registered X-ray and optical images by construction, which facilitates the generation of panoramic X-ray images based on the motion estimation of the X-ray source. Visual marker tracking is employed to estimate the camera motion and this estimated motion is also applied to the X-ray source. Our proposed method is suitable and practical for intra-operative usage generating panoramic X-ray images without the requirement of a fronto-parallel setup and overlapping X-ray images. The results show that the panoramic X-ray images generated by our method are accurate enough (errors less than 1%) for metric measurements and promise suitability for intra-operative clinical applications in trauma surgery.

  16. X-ray-induced photo-chemistry and X-ray absorption spectroscopy of biological samples

    OpenAIRE

    George, Graham N.; Pickering, Ingrid J.; Pushie, M. Jake; Nienaber, Kurt; Hackett, Mark J.; Ascone, Isabella; Hedman, Britt; Hodgson, Keith O.; Aitken, Jade B.; Levina, Aviva; Glover, Christopher; Lay, Peter A.

    2012-01-01

    X-ray-induced photo-chemistry of metal sites within biological molecules is a concern for X-ray absorption spectroscopy, X-ray crystallography and other techniques in which samples are illuminated with X-rays. The effects of X-ray-induced photo-chemistry are reviewed and the methods used to mitigate these in X-ray absorption spectroscopy are outlined.

  17. Dosimetric properties of megavoltage grid therapy

    International Nuclear Information System (INIS)

    Purpose: Grid therapy is a technique used to deliver a high dose of radiation (15-20 Gy) in a single fraction to many small volumes within a large treatment field. This treatment modality is used for the palliative treatment of large, deeply seated tumors, which have either been treated to tolerance with conventional radiation, or, due to massive tumor bulk, would most likely not benefit from a conventional course of radiation therapy. As the dose distribution from megavoltage grid therapy differs significantly from that of conventional radiation therapy (i.e., many large dose gradients exist within the tumor volume), we have measured various dosimetric properties inherent in this unique treatment modality. Methods and Materials: The grid is a 16 x 16 array of 1-cm diameter holes in a 7-cm thick piece of custom blocking material. The ratio of shielded to open surface area is 1:1. Depth dose, valley-to-peak ratios, and output factors for this square array grid were measured in a water phantom for several field sizes, as well as for a 1-cm diameter narrow beam using 6 MV and 25 MV photon beams. Results: The depth dose curves for the grid fields lie between those for an open portal and a narrow beam. For the 6-MV beam at dmax, the ratios of the doses delivered to the center of the shielded regions to that under the center of the holes, expressed as valley-to-peak ratios, range from 15 to 40%. At 10 cm, the ratios increase to between 25 and 45%. At 25 MV at both dmax and 10 cm, the valley-to-peak ratios are between 40 and 60%. The output factors, 0.89 for 6 MV and 0.77 for 25 MV, do not depend on field size. Conclusion: Megavoltage grid therapy is a unique treatment modality where the dose is delivered differentially to a large volume in one fraction. Characterization of the dosimetric properties has allowed clinical implementation of the grid

  18. Energy dependence measurement of small-type optically stimulated luminescence (OSL) dosimeter by means of characteristic X-rays induced with general diagnostic X-ray equipment.

    Science.gov (United States)

    Takegami, Kazuki; Hayashi, Hiroaki; Okino, Hiroki; Kimoto, Natsumi; Maehata, Itsumi; Kanazawa, Yuki; Okazaki, Tohru; Hashizume, Takuya; Kobayashi, Ikuo

    2016-01-01

    For X-ray inspections by way of general X-ray equipment, it is important to measure an entrance-skin dose. Recently, a small optically stimulated luminescence (OSL) dosimeter was made commercially available by Landauer, Inc. The dosimeter does not interfere with the medical images; therefore, it is expected to be a convenient detector for measuring personal exposure doses. In an actual clinical situation, it is assumed that X-rays of different energies will be detected by a dosimeter. For evaluation of the exposure dose measured by a dosimeter, it is necessary to know the energy dependence of the dosimeter. Our aim in this study was to measure the energy dependence of the OSL dosimeter experimentally in the diagnostic X-ray region. Metal samples weighing several grams were irradiated and, in this way, characteristic X-rays having energies ranging from 8 to 85 keV were generated. Using these mono-energetic X-rays, the dosimeter was irradiated. Simultaneously, the fluence of the X-rays was determined with a CdTe detector. The energy-dependent efficiency of the dosimeter was derived from the measured value of the dosimeter and the fluence. Moreover, the energy-dependent efficiency was calculated by Monte-Carlo simulation. The efficiency obtained in the experiment was in good agreement with that of the simulation. In conclusion, our proposed method, in which characteristic X-rays are used, is valuable for measurement of the energy dependence of a small OSL dosimeter in the diagnostic X-ray region. PMID:26589210

  19. Energy dependence measurement of small-type optically stimulated luminescence (OSL) dosimeter by means of characteristic X-rays induced with general diagnostic X-ray equipment.

    Science.gov (United States)

    Takegami, Kazuki; Hayashi, Hiroaki; Okino, Hiroki; Kimoto, Natsumi; Maehata, Itsumi; Kanazawa, Yuki; Okazaki, Tohru; Hashizume, Takuya; Kobayashi, Ikuo

    2016-01-01

    For X-ray inspections by way of general X-ray equipment, it is important to measure an entrance-skin dose. Recently, a small optically stimulated luminescence (OSL) dosimeter was made commercially available by Landauer, Inc. The dosimeter does not interfere with the medical images; therefore, it is expected to be a convenient detector for measuring personal exposure doses. In an actual clinical situation, it is assumed that X-rays of different energies will be detected by a dosimeter. For evaluation of the exposure dose measured by a dosimeter, it is necessary to know the energy dependence of the dosimeter. Our aim in this study was to measure the energy dependence of the OSL dosimeter experimentally in the diagnostic X-ray region. Metal samples weighing several grams were irradiated and, in this way, characteristic X-rays having energies ranging from 8 to 85 keV were generated. Using these mono-energetic X-rays, the dosimeter was irradiated. Simultaneously, the fluence of the X-rays was determined with a CdTe detector. The energy-dependent efficiency of the dosimeter was derived from the measured value of the dosimeter and the fluence. Moreover, the energy-dependent efficiency was calculated by Monte-Carlo simulation. The efficiency obtained in the experiment was in good agreement with that of the simulation. In conclusion, our proposed method, in which characteristic X-rays are used, is valuable for measurement of the energy dependence of a small OSL dosimeter in the diagnostic X-ray region.

  20. Low energy x-ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Woodruff, W.R.

    1981-06-05

    A subkilovolt spectrometer has been produced to permit high-energy-resolution, time-dependent x-ray intensity measurements. The diffracting element is a curved mica (d = 9.95A) crystal. To preclude higher order (n > 1) diffractions, a carbon x-ray mirror that reflects only photons with energies less than approx. 1.1 keV is utilized ahead of the diffracting element. The nominal energy range of interest is 800 to 900 eV. The diffracted photons are detected by a gold-surface photoelectric diode designed to have a very good frequency response, and whose current is recorded on an oscilloscope. A thin, aluminium light barrier is placed between the diffracting crystal and the photoelectric diode detector to keep any uv generated on or scattered by the crystal from illuminating the detector. High spectral energy resolution is provided by many photocathodes between 8- and 50-eV wide placed serially along the diffracted x-ray beam at the detector position. The spectrometer was calibrated for energy and energy dispersion using the Ni L..cap alpha../sub 1/ /sub 2/ lines produced in the LLNL IONAC accelerator and in third order using a molybdenum target x-ray tube. For the latter calibration the carbon mirror was replaced by one surfaced with rhodium to raise the cut-off energy to about 3 keV. The carbon mirror reflection dependence on energy was measured using one of our Henke x-ray sources. The curved mica crystal diffraction efficiency was measured on our Low-Energy x-ray (LEX) machine. The spectrometer performs well although some changes in the way the x-ray mirror is held are desirable. 16 figures.

  1. New achievements in X-ray optics——the X-ray lens and its applications

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An X-ray lens consists of a large number of X-ray capillaries. It can collect divergent X-rays emitted from an X-ray source and form a focused or parallel beam of high intensity. So it is an effective tool for adjusting and controlling wide bandwidth X-ray beams. In this paper, the X-ray lens made by the X-ray Optics Laboratory of Institute of Low Energy Nuclear Physics at Beijing Normal University and its applications in the field of X-ray analysis are presented.

  2. X-Ray Calorimeter Arrays for Astrophysics

    Science.gov (United States)

    Kilbourne, Caroline A.

    2009-01-01

    High-resolution x-ray spectroscopy is a powerful tool for studying the evolving universe. The grating spectrometers on the XMM and Chandra satellites started a new era in x-ray astronomy, but there remains a need for instrumentation that can provide higher spectral resolution with high throughput in the Fe-K band (around 6 keV) and can enable imaging spectroscopy of extended sources, such as supernova remnants and galaxy clusters. The instrumentation needed is a broad-band imaging spectrometer - basically an x-ray camera that can distinguish tens of thousands of x-ray colors. The potential benefits to astrophysics of using a low-temperature calorimeter to determine the energy of an incident x-ray photon via measurement of a small change in temperature was first articulated by S. H. Moseley over two decades ago. In the time since, technological progress has been steady, though full realization in an orbiting x-ray telescope is still awaited. A low-temperature calorimeter can be characterized by the type of thermometer it uses, and three types presently dominate the field. The first two types are temperature-sensitive resistors - semiconductors in the metal-insulator transition and superconductors operated in the superconducting-normal transition. The third type uses a paramagnetic thermometer. These types can be considered the three generations of x-ray calorimeters; by now each has demonstrated a resolving power of 2000 at 6 keV, but only a semiconductor calorimeter system has been developed to spaceflight readiness. The Soft X-ray Spectrometer on Astro-H, expected to launch in 2013, will use an array of silicon thermistors with I-IgTe x-ray absorbers that will operate at 50 mK. Both the semiconductor and superconductor calorimeters have been implemented in small arrays, kilo-pixel arrays of the superconducting calorimeters are just now being produced, and it is anticipated that much larger arrays will require the non-dissipative advantage of magnetic thermometers.

  3. Relative response of the alanine dosimeter to medium energy x-rays

    Science.gov (United States)

    Anton, M.; Büermann, L.

    2015-08-01

    The response of the alanine dosimeter to kilovoltage x-rays with respect to the dose to water was measured, relative to the response to Co-60 radiation. Two series of x-ray qualities were investigated, one ranging from 30 kV to 100 kV tube voltage (TW series), the other one ranging from 70 kV to 280 kV (TH series). Due to the use of the water calorimeter as a primary standard, the uncertainty of the delivered dose is significantly lower than for other published data. The alanine response was measured as described in a previous publication (Anton et al 2013 Phys. Med. Biol. 58 3259-82). The uncertainty component due to the alanine measurement and analysis is ⩽0.4%, the major part of the combined uncertainty of the relative response originates from the uncertainty of the delivered dose. The relative uncertainties of the relative response vary from ⩽2% for the TW series to ⩽1.1% for the TH series. Different from the behaviour of the alanine dosimeter for megavoltage x-rays or electrons, the relative response drops significantly from unity for Co-60 radiation to less than 64% for the TW quality with a tube voltage of 30 kV. In order to reproduce this behaviour through Monte Carlo simulations, not only the ratio of the absorbed dose to alanine to the absorbed dose to water has to be known, but also the intrinsic efficiency, i.e. the dependence of the number of free radicals generated per unit of absorbed dose on the photon energy. This quantity is not yet accessible for the TW series. For a possible use of the alanine dosimeter for kilovoltage x-rays, for example in electronic brachytherapy, users should rely on the measured data for the relative response which have become available with this publication.

  4. Relative response of the alanine dosimeter to medium energy x-rays

    International Nuclear Information System (INIS)

    The response of the alanine dosimeter to kilovoltage x-rays with respect to the dose to water was measured, relative to the response to Co-60 radiation.Two series of x-ray qualities were investigated, one ranging from 30 kV to 100 kV tube voltage (TW series), the other one ranging from 70 kV to 280 kV (TH series). Due to the use of the water calorimeter as a primary standard, the uncertainty of the delivered dose is significantly lower than for other published data. The alanine response was measured as described in a previous publication (Anton et al 2013 Phys. Med. Biol. 58 3259–82). The uncertainty component due to the alanine measurement and analysis is ⩽0.4%, the major part of the combined uncertainty of the relative response originates from the uncertainty of the delivered dose. The relative uncertainties of the relative response vary from ⩽2% for the TW series to ⩽1.1% for the TH series.Different from the behaviour of the alanine dosimeter for megavoltage x-rays or electrons, the relative response drops significantly from unity for Co-60 radiation to less than 64% for the TW quality with a tube voltage of 30 kV. In order to reproduce this behaviour through Monte Carlo simulations, not only the ratio of the absorbed dose to alanine to the absorbed dose to water has to be known, but also the intrinsic efficiency, i.e. the dependence of the number of free radicals generated per unit of absorbed dose on the photon energy. This quantity is not yet accessible for the TW series.For a possible use of the alanine dosimeter for kilovoltage x-rays, for example in electronic brachytherapy, users should rely on the measured data for the relative response which have become available with this publication. (paper)

  5. Relative response of the alanine dosimeter to medium energy x-rays.

    Science.gov (United States)

    Anton, M; Büermann, L

    2015-08-01

    The response of the alanine dosimeter to kilovoltage x-rays with respect to the dose to water was measured, relative to the response to Co-60 radiation.Two series of x-ray qualities were investigated, one ranging from 30 kV to 100 kV tube voltage (TW series), the other one ranging from 70 kV to 280 kV (TH series). Due to the use of the water calorimeter as a primary standard, the uncertainty of the delivered dose is significantly lower than for other published data. The alanine response was measured as described in a previous publication (Anton et al 2013 Phys. Med. Biol. 58 3259-82). The uncertainty component due to the alanine measurement and analysis is ⩽0.4%, the major part of the combined uncertainty of the relative response originates from the uncertainty of the delivered dose. The relative uncertainties of the relative response vary from ⩽2% for the TW series to ⩽1.1% for the TH series.Different from the behaviour of the alanine dosimeter for megavoltage x-rays or electrons, the relative response drops significantly from unity for Co-60 radiation to less than 64% for the TW quality with a tube voltage of 30 kV. In order to reproduce this behaviour through Monte Carlo simulations, not only the ratio of the absorbed dose to alanine to the absorbed dose to water has to be known, but also the intrinsic efficiency, i.e. the dependence of the number of free radicals generated per unit of absorbed dose on the photon energy. This quantity is not yet accessible for the TW series.For a possible use of the alanine dosimeter for kilovoltage x-rays, for example in electronic brachytherapy, users should rely on the measured data for the relative response which have become available with this publication.

  6. X-ray spectroscopy an introduction

    CERN Document Server

    Agarwal, Bipin K

    1979-01-01

    Rontgen's discovery of X-rays in 1895 launched a subject which became central to the development of modern physics. The verification of many of the predic­ tions of quantum theory by X-ray spectroscopy in the early part of the twen­ tieth century stimulated great interest in thi's area, which has subsequently influenced fields as diverse as chemical physics, nuclear physics, and the study of the electronic properties of solids, and led to the development of techniques such as Auger, Raman, and X-ray photoelectron spectroscopy. The improvement of the theoretical understanding of the physics underlying X-ray spectroscopy has been accompanied by advances in experimental techniques, and the subject provides an instructive example of how progress on both these fronts can be mutually beneficial. This book strikes a balance between his­ torical description, which illustrates this symbiosis, and the discussion of new developments. The application of X-ray spectroscopic methods to the in­ vestigation of chemical b...

  7. Advanced X-ray diffractive optics

    Energy Technology Data Exchange (ETDEWEB)

    Vila-Comamala, J; Jefimovs, K; Sarkar, S S; Solak, H H; Guzenko, V A; Stampanoni, M; Marone, F; Raabe, J; Tzvetkov, G; Grolimund, D; Borca, C N; David, C [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Pilvi, T; Ritala, M [Department of Chemistry, FIN-00014 University of Helsinki (Finland); Fink, R H [Friedrich-Alexander Universitaet, D-91058 Erlangen (Germany); Kaulich, B, E-mail: joan.vila@psi.c [ELETTRA Sincrotrone, I-34012 Basovizza (Italy)

    2009-09-01

    X-ray microscopy greatly benefits from the advances in x-ray optics. At the Paul Scherrer Institut, developments in x-ray diffractive optics include the manufacture and optimization of Fresnel zone plates (FZPs) and diffractive optical elements for both soft and hard x-ray regimes. In particular, we demonstrate here a novel method for the production of ultra-high resolution FZPs. This technique is based on the deposition of a zone plate material (iridium) onto the sidewalls of a prepatterned template structure (silicon) by atomic layer deposition. This approach overcomes the limitations due to electron-beam writing of dense patterns in FZP fabrication and provides a clear route to push the resolution into sub-10 nm regime. A FZP fabricated by this method was used to resolve test structures with 12 nm lines and spaces at the scanning transmission x-ray microscope of the PolLux beamline of the Swiss Light Source at 1.2 keV photon energy.

  8. Polarisation modulation in X-ray binaries

    Science.gov (United States)

    Ingram, Adam; Maccarone, Thomas

    2016-07-01

    X-ray polarimetry promises to provide a powerful new lever arm for studying accretion onto black holes with the next generation of X-ray telescopes. I will discuss how polarisation can be used to help constrain the physical origin of quasi-periodic oscillations (QPOs) observed in the X-ray light curves of accreting black holes. QPOs may be signatures of the frame dragging effect: in General Relativity, a spinning black hole twists up the surrounding space-time, causing vertical precession of nearby orbits. In the truncated disc / precessing inner flow model, the entire inner accretion flow precesses as a solid body causing a modulation in the X-ray flux through solid angle and Doppler effects. This model also predicts the observed polarisation of the X-ray signal to vary quasi-periodically. I will summarise our work to model the polarisation signal from a precessing accretion flow, starting with simple assumptions about the emission mechanism but taking General Relativity fully into account. We find that it should be possible to measure the predicted modulation in polarisation degree for a reasonable region of parameter space with a polarimeter capable of detecting ~60 counts per second from a bright black hole binary. I will also show that sensitivity can be greatly improved by correlating the signal with a high count rate reference band signal.

  9. Optics for coherent X-ray applications.

    Science.gov (United States)

    Yabashi, Makina; Tono, Kensuke; Mimura, Hidekazu; Matsuyama, Satoshi; Yamauchi, Kazuto; Tanaka, Takashi; Tanaka, Hitoshi; Tamasaku, Kenji; Ohashi, Haruhiko; Goto, Shunji; Ishikawa, Tetsuya

    2014-09-01

    Developments of X-ray optics for full utilization of diffraction-limited storage rings (DLSRs) are presented. The expected performance of DLSRs is introduced using the design parameters of SPring-8 II. To develop optical elements applicable to manipulation of coherent X-rays, advanced technologies on precise processing and metrology were invented. With propagation-based coherent X-rays at the 1 km beamline of SPring-8, a beryllium window fabricated with the physical-vapour-deposition method was found to have ideal speckle-free properties. The elastic emission machining method was utilized for developing reflective mirrors without distortion of the wavefronts. The method was further applied to production of diffraction-limited focusing mirrors generating the smallest spot size in the sub-10 nm regime. To enable production of ultra-intense nanobeams at DLSRs, a low-vibration cooling system for a high-heat-load monochromator and advanced diagnostic systems to characterize X-ray beam properties precisely were developed. Finally, new experimental schemes for combinative nano-analysis and spectroscopy realised with novel X-ray optics are discussed. PMID:25177986

  10. Nonlinear X-ray Compton Scattering

    CERN Document Server

    Fuchs, Matthias; Chen, Jian; Ghimire, Shambhu; Shwartz, Sharon; Kozina, Michael; Jiang, Mason; Henighan, Thomas; Bray, Crystal; Ndabashimiye, Georges; Bucksbaum, P H; Feng, Yiping; Herrmann, Sven; Carini, Gabriella; Pines, Jack; Hart, Philip; Kenney, Christopher; Guillet, Serge; Boutet, Sebastien; Williams, Garth; Messerschmidt, Marc; Seibert, Marvin; Moeller, Stefan; Hastings, Jerome B; Reis, David A

    2015-01-01

    X-ray scattering is a weak linear probe of matter. It is primarily sensitive to the position of electrons and their momentum distribution. Elastic X-ray scattering forms the basis of atomic structural determination while inelastic Compton scattering is often used as a spectroscopic probe of both single-particle excitations and collective modes. X-ray free-electron lasers (XFELs) are unique tools for studying matter on its natural time and length scales due to their bright and coherent ultrashort pulses. However, in the focus of an XFEL the assumption of a weak linear probe breaks down, and nonlinear light-matter interactions can become ubiquitous. The field can be sufficiently high that even non-resonant multiphoton interactions at hard X-rays wavelengths become relevant. Here we report the observation of one of the most fundamental nonlinear X-ray-matter interactions, the simultaneous Compton scattering of two identical photons producing a single photon at nearly twice the photon energy. We measure scattered...

  11. X-ray absorption spectroscopy of metalloproteins.

    Science.gov (United States)

    Ward, Jesse; Ollmann, Emily; Maxey, Evan; Finney, Lydia A

    2014-01-01

    Metalloproteins are enormously important in biology. While a variety of techniques exist for studying metals in biology, X-ray absorption spectroscopy is particularly useful in that it can determine the local electronic and physical structure around the metal center, and is one of the few avenues for studying "spectroscopically silent" metal ions like Zn(II) and Cu(I) that have completely filled valence bands. While X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) are useful for studying metalloprotein structure, they suffer the limitation that the detected signal is an average of all the various metal centers in the sample, which limits its usefulness for studying metal centers in situ or in cell lysates. It would be desirable to be able to separate the various proteins in a mixture prior to performing X-ray absorption studies, so that the derived signal is from one species only. Here we describe a method for performing X-ray absorption spectroscopy on protein bands following electrophoretic separation and western blotting.

  12. X-ray spectra for mamography

    International Nuclear Information System (INIS)

    By means of Monte Carlo methods the X-ray spectra that produce Mammography equipment have been obtained. The mammographs are widely used with the purpose of diagnosing the cancer of the mammary glands. Different makers and mammographs models are distinguished by the voltage capacity and the current, exist as well as in the target type and filter. The targets that are used are Mo, Rh and W and the filters are Mo, Rh, Al and Be. In this work the results obtained by means of the MCNP code of the X-ray spectra take place when an electron beam of 28 keV is made impact on Mo, Rh and W targets, as well as the spectra that result of filtering these X rays using different types of filters. The resulting spectra contain the continuous spectrum of the stopping radiation, as well as the X rays characteristic of the used target. The utility of estimating the spectra of X rays by means of Monte Carlo is that it can use to estimate the absorbed dose by the gland, as well as the absorbed dose by other organs. It also allows to calculate the detector response. (Author)

  13. Supergiant Fast X-ray Transients

    CERN Document Server

    Sidoli, Lara

    2011-01-01

    The phenomenology of a subclass of High Mass X-ray Binaries hosting a blue supergiant companion, the so-called Supergiant Fast X-ray Transients (SFXTs), is reviewed. Their number is growing, mainly thanks to the discoveries performed by the INTEGRAL satellite, then followed by soft X-rays observations (both aimed at refining the source position and at monitoring the source behavior) leading to the optical identification of the blue supergiant nature of the donor star. Their defining properties are a transient X-ray activity consisting of sporadic, fast and bright flares, (each with a variable duration between a few minutes and a few hours), reaching 1E36-1E37 erg/s. The quiescence is at a luminosity of 1E32 erg/s, while their more frequent state consists of an intermediate X-ray emission of 1E33-1E34 erg/s (1-10 keV). Only the brightest flares are detected by INTEGRAL (>17 keV) during short pointings, with no detected persistent emission. The physical mechanism driving the short outbursts is still debated, al...

  14. X-ray emission processes in stars

    CERN Document Server

    Testa, Paola

    2010-01-01

    A decade of X-ray stellar observations with Chandra and XMM-Newton has led to significant advances in our understanding of the physical processes at work in hot (magnetized) plasmas in stars and their immediate environment, providing new perspectives and challenges, and in turn the need for improved models. The wealth of high-quality stellar spectra has allowed us to investigate, in detail, the characteristics of the X-ray emission across the HR diagram. Progress has been made in addressing issues ranging from classical stellar activity in stars with solar-like dynamos (such as flares, activity cycles, spatial and thermal structuring of the X-ray emitting plasma, evolution of X-ray activity with age), to X-ray generating processes (e.g. accretion, jets, magnetically confined winds) that were poorly understood in the pre-Chandra/XMM-Newton era. I discuss the progress made in the study of high energy stellar physics and its impact in a wider astrophysical context, focusing on the role of spectral diagnostics no...

  15. Poland综合征上肢骨关节X线异常改变及临床意义%X-ray characteristics of upper limb joints and their clinical significance in Poland syndrome

    Institute of Scientific and Technical Information of China (English)

    张申申; 田文; 赵俊会; 郭阳; 殷耀斌; 马炜; 于龙彪; 田光磊

    2014-01-01

    Objective To analyze and summarize the X-ray characteristics of upper limb bone and joint in 22 cases of Poland syndrome,and explore the clinical significance of these findings.Methods The following parameters were measured on X-ray films of bilateral upper limb of 22 patients with Poland syndrome:upper limbs length,radius length,ulna length,humerus length,length and width of the capitate,length and width of proximal phalanx of the thumb,length,width and morphology of middle phalanx of the long finger,and the number of carpal bone ossification center.Statistical analysis was carried out to compare findings from various zones.Results The incidence of involvement was higher on the right side (68.18 %) than on the left side (31.82%).More males (81.82%) were affected than females (18.18 %).Bony syndactyly did not occur in any of the cases.Absence of the third middle phalangeal bone was a general phenomenon,indicating the severe involvement of the central column skeleton.Abnormal changes of thumb proximal phalanx and the capitate were obvious.Statistical analysis showed significant individual differences.The humerus,ulna,and radius were all shorter.Conclusion In Poland syndrome upper limb bone and joint changes mainly occur in the short tubular bones of the hand,which appear to be smaller or absent.Upper extremity long tubular bones are shorter.There is also arrested carpal bone development.%目的 通过对22例Poland综合征患者上肢骨关节的X线测量,分析、总结其特点,初步探索其临床意义.方法 测量22例患者双侧上肢X线片,记录下列参数:上肢全长、尺骨全长、桡骨全长、肱骨全长、头状骨长度及宽度、拇指近节指骨长度及宽度、中指中节指骨长度及宽度、腕骨骨化中心个数、中指中节指骨形态.对其进行区间估计统计学分析.结果 从本组资料看,右侧的构成比(68.18%)高于左侧(31.82%),男性的构成比(81.82%)高于女性(18.18%).所有病例

  16. Compact X-ray sources: X-rays from self-reflection

    Science.gov (United States)

    Mangles, Stuart P. D.

    2012-05-01

    Laser-based particle acceleration offers a way to reduce the size of hard-X-ray sources. Scientists have now developed a simple scheme that produces a bright flash of hard X-rays by using a single laser pulse both to generate and to scatter an electron beam.

  17. X-ray Spectral Variation of Eta Carinae through the 2003 X-ray Minimum

    CERN Document Server

    Hamaguchi, K; Gull, T; Ishibashi, K; Pittard, J M; Hillier, D J; Damineli, A; Davidson, K; Nielsen, K E; Kober, G V; Hamaguchi, Kenji; Corcoran, Michael F.; Gull, Theodore; Ishibashi, Kazunori; Pittard, Julian M.; Damineli, Augusto; Davidson, Kris; Nielsen, Krister E.; Kober, Gladys Vieira

    2007-01-01

    We report the results of an X-ray observing campaign on the massive, evolved star Eta Carinae, concentrating on the 2003 X-ray minimum as seen by the XMM-Newton observatory. These are the first spatially-resolved X-ray monitoring observations of the stellar X-ray spectrum during the minimum. The hard X-ray emission, believed to be associated with the collision of Eta Carinae's wind with the wind from a massive companion star, varied strongly in flux on timescales of days, but not significantly on timescales of hours. The lowest X-ray flux in the 2-10 keV band seen by XMM-Newton was only 0.7% of the maximum seen by RXTE just before the X-ray minimum. The slope of the X-ray continuum above 5 keV did not vary in any observation, which suggests that the electron temperature of the hottest plasma associated with the stellar source did not vary significantly at any phase. Through the minimum, the absorption to the stellar source increased by a factor of 5-10 to NH ~3-4E23 cm-2. The thermal Fe XXV emission line show...

  18. Linking Jet Emission, X-ray States and Hard X-ray Tails in the Neutron Star X-ray Binary GX 17+2

    OpenAIRE

    Migliari, S.; Miller-Jones, J. C. A.; Fender, R. P.; Homan, J.; T. Di Salvo; Rothschild, R. E.; Rupen, M P; Tomsick, J. A.; Wijnands, R.; van der Klis, M.

    2007-01-01

    We present the results from simultaneous radio (Very Large Array) and X-ray (Rossi-X-ray Timing Explorer) observations of the Z-type neutron star X-ray binary GX~17+2. The aim is to assess the coupling between X-ray and radio properties throughout its three rapidly variable X-ray states and during the time-resolved transitions. These observations allow us, for the first time, to investigate quantitatively the possible relations between the radio emission and the presence of the hard X-ray tai...

  19. X-ray resonant magnetic scattering ellipsometer

    International Nuclear Information System (INIS)

    It is very difficult to characterize the polarization of a synchrotron radiation source in the soft and/or intermediate x-ray energy region particularly from 1 to 2 keV. Conventional multilayer mirror or single-crystal polarimeters do not work over this energy region because their throughput (the reflectivities combined with the phase shift) becomes insignificant. In this paper, we present a new ellipsometer scheme that is able to fully characterize the polarization of synchrotron radiation sources in this energy region. It is based on the dichroic x-ray resonant ferromagnetic scattering that yields information on both the polarization of the x-ray and the material (element specific) dielectric-constant tensor [C.-C. Kao et al., Phys. Rev. B 50, 9599 (1994)] due to the interband ferromagnetic Kerr effect [B.R. Cooper, Phys. Rev. A 139, 1504 (1965)]. copyright 1996 American Institute of Physics

  20. Simulating X-ray Observations with Python

    CERN Document Server

    ZuHone, John A; Hallman, Eric J; Randall, Scott W; Foster, Adam R; Schmid, Christian

    2014-01-01

    X-ray astronomy is an important tool in the astrophysicist's toolkit to investigate high-energy astrophysical phenomena. Theoretical numerical simulations of astrophysical sources are fully three-dimensional representations of physical quantities such as density, temperature, and pressure, whereas astronomical observations are two-dimensional projections of the emission generated via mechanisms dependent on these quantities. To bridge the gap between simulations and observations, algorithms for generating synthetic observations of simulated data have been developed. We present an implementation of such an algorithm in the yt analysis software package. We describe the underlying model for generating the X-ray photons, the important role that yt and other Python packages play in its implementation, and present a detailed workable example of the creation of simulated X-ray observations.

  1. X-Ray Detector Simulations - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Tina, Adrienne [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-20

    The free-electron laser at LCLS produces X-Rays that are used in several facilities. This light source is so bright and quick that we are capable of producing movies of objects like proteins. But making these movies would not be possible without a device that can detect the X-Rays and produce images. We need X-Ray cameras. The challenges LCLS faces include the X-Rays’ high repetition rate of 120 Hz, short pulses that can reach 200 femto-seconds, and extreme peak brightness. We need detectors that are compatible with this light source, but before they can be used in the facilities, they must first be characterized. My project was to do just that, by making a computer simulation program. My presentation discusses the individual detectors I simulated, the details of my program, and how my project will help determine which detector is most useful for a specific experiment.

  2. X-ray optics developments at ESA

    DEFF Research Database (Denmark)

    Bavdaz, M.; Wille, E.; Wallace, K.;

    2013-01-01

    Future high energy astrophysics missions will require high performance novel X-ray optics to explore the Universe beyond the limits of the currently operating Chandra and Newton observatories. Innovative optics technologies are therefore being developed and matured by the European Space Agency (ESA......) in collaboration with research institutions and industry, enabling leading-edge future science missions. Silicon Pore Optics (SPO) [1 to 21] and Slumped Glass Optics (SGO) [22 to 29] are lightweight high performance X-ray optics technologies being developed in Europe, driven by applications in observatory class...... reflective coatings [30 to 35]. In addition, the progress with the X-ray test facilities and associated beam-lines is discussed [36]. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only....

  3. X- rays and matter- the basic interactions

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens

    2008-01-01

    In this introductory article we attempt to provide the theoretical basis for developing the interaction between X-rays and matter, so that one can unravel properties of matter by interpretation of X-ray experiments on samples. We emphasize that we are dealing with the basics, which means that we...... shall limit ourselves to a discussion of the interaction of an X-ray photon with an isolated atom, or rather with a single electron in a Hartree-Fock atom. Subsequent articles in this issue deal with more complicated - and interesting - forms of matter encompassing many atoms or molecules. To cite...... this article: J. Als-Nielsen, C. R. Physique 9 (2008). Udgivelsesdato: 18 April...

  4. X-Ray Wakes in Abell 160

    CERN Document Server

    Drake, N; Sakelliou, I; Pinkney, J C; Drake, Nick; Merrifield, Michael R.; Sakelliou, Irini; Pinkney, Jason C.

    2000-01-01

    `Wakes' of X-ray emission have now been detected trailing behind a few (at least seven) elliptical galaxies in clusters. To quantify how widespread this phenomenon is, and what its nature might be, we have obtained a deep (70 ksec) X-ray image of the poor cluster Abell 160 using the ROSAT HRI. Combining the X-ray data with optical positions of confirmed cluster members, and applying a statistic designed to search for wake-like excesses, we confirm that this phenomenon is observed in galaxies in this cluster. The probability that the detections arise from chance is less than 0.0038. Further, the wakes are not randomly distributed in direction, but are preferentially oriented pointing away from the cluster centre. This arrangement can be explained by a simple model in which wakes arise from the stripping of their host galaxies' interstellar media due to ram pressure against the intracluster medium through which they travel.

  5. The Chandra X-Ray Optics

    CERN Document Server

    Weisskopf, Martin C

    2011-01-01

    Significant advances in science always take place when the state of the art in instrumentation improves dramatically. NASA's Chandra X-Ray Observatory represents such an advance. Launched in July of 1999, Chandra is an observatory designed to study the x-ray emission from all categories of astronomical objects --- from comets, planets, and normal stars to quasars, galaxies, and clusters of galaxies. At the heart of this observatory is the precision X-Ray optic that has been vital for Chandra's outstanding success and which features an angular resolution improved by an order of magnitude compared to its forerunners. The Chandra mission is now entering its 13-th year of operation. Given that the Observatory was designed for a minimum of 3 years of operation testifies to its robust and carefully thought out design. We review the design and construction of the remarkable telescope, present examples of its usage for astronomy and astrophysics, and speculate upon the future.

  6. Electromagnetically induced transparency for x rays

    CERN Document Server

    Buth, Christian; Young, Linda

    2007-01-01

    Electromagnetically induced transparency (EIT) is predicted for x rays in laser-dressed neon gas. The x-ray photoabsorption cross section and polarizability near the Ne K edge are calculated using an ab initio theory suitable for optical strong-field problems. The laser wavelength is tuned close to the transition between 1s^-1 3s and 1s^-1 3p (approximately 800nm). The minimum laser intensity required to observe EIT is of the order of 10^12 W/cm^2. The ab initio results are discussed in terms of an exactly solvable three-level model. This work opens new opportunities for research with ultrafast x-ray sources.

  7. The quantum X-ray radiology apparatus

    CERN Document Server

    Hilt, B; Prevot, G

    2000-01-01

    The paper entitled 'New Quantum Detection System for Very Low Dose X-ray Radiology', presented at the talk session, discusses the preliminary data obtained using a new quantum X-ray radiology system with a high-efficiency solid-state detector and highly sensitive electronics, making it possible to reduce significantly the dose administered to a patient in X-ray radiology examinations. The present paper focuses more on the technological aspects of the apparatus, such as the integration of the detector with the two Asics, and the computer system. Namely, it is shown how the computer system calibrates the detection system, acquires the data in real time, and controls the scan parameters and image filtering process.

  8. Supernova remnants: the X-ray perspective

    Science.gov (United States)

    Vink, Jacco

    2012-12-01

    Supernova remnants are beautiful astronomical objects that are also of high scientific interest, because they provide insights into supernova explosion mechanisms, and because they are the likely sources of Galactic cosmic rays. X-ray observations are an important means to study these objects. And in particular the advances made in X-ray imaging spectroscopy over the last two decades has greatly increased our knowledge about supernova remnants. It has made it possible to map the products of fresh nucleosynthesis, and resulted in the identification of regions near shock fronts that emit X-ray synchrotron radiation. Since X-ray synchrotron radiation requires 10-100 TeV electrons, which lose their energies rapidly, the study of X-ray synchrotron radiation has revealed those regions where active and rapid particle acceleration is taking place. In this text all the relevant aspects of X-ray emission from supernova remnants are reviewed and put into the context of supernova explosion properties and the physics and evolution of supernova remnants. The first half of this review has a more tutorial style and discusses the basics of supernova remnant physics and X-ray spectroscopy of the hot plasmas they contain. This includes hydrodynamics, shock heating, thermal conduction, radiation processes, non-equilibrium ionization, He-like ion triplet lines, and cosmic ray acceleration. The second half offers a review of the advances made in field of X-ray spectroscopy of supernova remnants during the last 15 year. This period coincides with the availability of X-ray imaging spectrometers. In addition, I discuss the results of high resolution X-ray spectroscopy with the Chandra and XMM-Newton gratings. Although these instruments are not ideal for studying extended sources, they nevertheless provided interesting results for a limited number of remnants. These results provide a glimpse of what may be achieved with future microcalorimeters that will be available on board future X-ray

  9. Position sensitive x-ray detector

    International Nuclear Information System (INIS)

    A multi ware position sensitive gas counter for X-ray detection was developed in our laboratory, making use of commercial delay-lines for position sensing. Six delay-line chips (50 ns delay each, 40 Mhz cut-off frequency) cover a total sensitive length of 150 mm leading to a delay-risetime ratio that allows for a high-resolution position detection. Tests using the 5,9 keV X-ray line from a 55 Fe source and integral linearity better than 0,1% and a maximal differential linearity of ±4,0% were obtained operating the detector with an Ar-C H4 (90%-10%) gas mixture at 700 torr. Similar tests were performed, using the 8,04 keV line from a Cu x-ray tube. A total resolution of 330 μm, and the same integral and differential linearities were obtained. (author)

  10. Strong X-ray emission from electrified insulators.

    Science.gov (United States)

    Inada, Nobuya; Maeda, Kuniko; Kawai, Jun

    2005-07-01

    Terasawa reported strong X-ray emission from charged-up insulators, and proposed an X-ray production device only using the electrification. We constructed a similar device and studied the conditions of X-ray emission. It was shown that X-rays could be produced without supplying electrons from a filament. PMID:16038514

  11. Marriage of x-ray and optical astronomy

    International Nuclear Information System (INIS)

    An historical discussion of the relation of x-ray and optical astronomy is given including distances within our galaxy, the optical identification of x-ray sources, the binary x-ray stars, neutron stars and black holes, a program in x-ray astronomy, and future missions

  12. Digital X-ray imager

    CERN Document Server

    LLNL &MedOptics Corporation

    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 so...

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

    Directory of Open Access Journals (Sweden)

    Susan Zappala

    Full Text Available 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.

  14. Energy resolved X-ray grating interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Thuering, T.; Stampanoni, M. [Swiss Light Source, Paul Scherrer Institut, Villigen PSI (Switzerland); Institute for Biomedical Engineering, Swiss Federal Institute of Technology, Zurich (Switzerland); Barber, W. C.; Iwanczyk, J. S. [DxRay, Inc., Northridge, California 91324 (United States); Seo, Y.; Alhassen, F. [UCSF Physics Research Laboratory, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California 94143 (United States)

    2013-05-13

    Although compatible with polychromatic radiation, the sensitivity in X-ray phase contrast imaging with a grating interferometer is strongly dependent on the X-ray spectrum. We used an energy resolving detector to quantitatively investigate the dependency of the noise from the spectral bandwidth and to consequently optimize the system-by selecting the best energy band matching the experimental conditions-with respect to sensitivity maximization and, eventually, dose. Further, since theoretical calculations of the spectrum are usually limited due to non-ideal conditions, an energy resolving detector accurately quantifies the spectral changes induced by the interferometer including flux reduction and beam hardening.

  15. Tantalum/Copper X-Ray Targets

    Science.gov (United States)

    Waters, William J.; Edmonds, Brian

    1993-01-01

    Lewis Research Center developed unique solution to subsidiary problem of fabrication of x-ray target. Plasma spraying enabled fabrication of lightweight, high-performance targets. Power settings, atmosphere-control settings, rate of deposition, and other spraying parameters developed. Thin coats of tantalum successfully deposited on copper targets. Targets performed successfully in tests and satisfied all criteria expressed in terms of critical parameters. Significantly reduces projected costs of fabrication of targets and contributes to development of improved, long-lived, lightweight x-ray system.

  16. Atomic Data for X-ray Astrophysics

    CERN Document Server

    Kallman, T R

    2006-01-01

    We review the available atomic data used for interpreting and modeling X-ray observations. The applications for these data can be divided into several levels of detail, ranging from compilations which can be used with direct inspection of raw data, such as line finding lists, to synthetic spectra which attempt to fit to an entire observed dataset simultaneously. This review covers cosmic sources driven by both electron ionization and photoionization and touches briefly on planetary surfaces and atmospheres. We review all of this, the applications to X-ray astronomy, the available data, recommendations for astronomical users, and attempt to point out the applications where the shortcomings are greatest

  17. X-Ray Transition Energies Database

    Science.gov (United States)

    SRD 128 X-Ray Transition Energies Database (Web, free access)   This X-ray transition table provides the energies and wavelengths for the K and L transitions connecting energy levels having principal quantum numbers n = 1, 2, 3, and 4. The elements covered include Z = 10, neon to Z = 100, fermium. There are two unique features of this data base: (1) a serious attempt to have all experimental values on a scale consistent with the International System of measurement (the SI) and (2) inclusion of accurate theoretical estimates for all transitions.

  18. Commercial Applications of X Ray Spectrometric Techniques

    International Nuclear Information System (INIS)

    In the 21st century, the X-ray fluorescence (XRF) technique is widely used in process control, industrial applications and for routine elemental analysis. The technique has a multielement capability capable of detecting elements with Z ≥ 10, with a few instruments capable of detecting also elements with Z ≥ 5. It is characterized by a non-destructive analysis process and relatively good detection limits, typically one part per million, for a wide range of elements. The first commercial XRF instruments were introduced to the market about 50 years ago. They were the wavelength dispersive X ray fluorescence (WDXRF) spectrometers utilizing Bragg’s law and reflection on crystal lattices for sequential elemental analysis of sample composition. The advances made in radiation detector technology, especially the introduction of semiconductor detectors, improvements in signal processing electronics, availability and exponential growth of personal computer market led to invention of energy dispersive X ray fluorescence (EDXRF) technique. The EDXRF is more cost effective as compared to WDXRF. It also allows for designing compact instruments. Such instruments can be easily tailored to the needs of different customers, integrated with industrial installations, and also miniaturized for the purpose of in-situ applications. The versatility of the technique has been confirmed in a spectacular way by using the XRF and X-ray spectrometric techniques, among few others, during the NASA and ESA missions in search for the evidence of life and presence of water on the surface of Mars. The XRF technique has achieved its strong position within the atomic spectroscopy group of analytical techniques not only due to its versatility but also due to relatively low running costs, as compared to the commonly used methods, e.g., atomic absorption spectrometry (AAS) or inductively coupled plasma atomic emission/mass spectrometry (ICP-AES/MS). Presently, the XRF technique together with X ray

  19. Radiobiological studies using gamma and x rays.

    Energy Technology Data Exchange (ETDEWEB)

    Potter, Charles Augustus; Longley, Susan W.; Scott, Bobby R.; Lin, Yong; Wilder, Julie; Hutt, Julie A.; Padilla, Mabel T.; Gott, Katherine M.

    2013-02-01

    There are approximately 500 self-shielded research irradiators used in various facilities throughout the U.S. These facilities use radioactive sources containing either 137Cs or 60Co for a variety of biological investigations. A report from the National Academy of Sciences[1] described the issues with security of particular radiation sources and the desire for their replacement. The participants in this effort prepared two peer-reviewed publications to document the results of radiobiological studies performed using photons from 320-kV x rays and 137Cs on cell cultures and mice. The effectiveness of X rays was shown to vary with cell type.

  20. Dose levels in conventional X-rays

    International Nuclear Information System (INIS)

    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)

  1. Cosmology with X-ray Cluster Baryons

    Energy Technology Data Exchange (ETDEWEB)

    Linder, Eric V.

    2007-04-10

    X-ray cluster measurements interpreted with a universal baryon/gas mass fraction can theoretically serve as a cosmological distance probe. We examine issues of cosmological sensitivity for current (e.g., Chandra X-ray Observatory, XMM-Newton) and next generation (e.g., Con-X, XEUS) observations, along with systematic uncertainties and biases. To give competitive next generation constraints on dark energy, we find that systematics will need to be controlled to better than 1percent and any evolution in f_gas (and other cluster gas properties) must be calibrated so the residual uncertainty is weaker than (1+z)0.03.

  2. X-ray tomography detection methods

    International Nuclear Information System (INIS)

    The improvement in the performance of X-ray tomographs involves the study of more efficient detectors, hence the important effort now being undertaken by various teams in the design of new detection systems. After defining the parameters which make it possible to select a detection method for an X-ray tomograph, the technical and operating characteristics of the following detectors are briefly reviewed: gas ionization chamber, multiwire grid chambers, ionization chamber with a condensed medium (liquid xenon), scintillation detector (with scintillator and photodetector) and semiconductor detectors (CdTe and HgI2) operating at ambient temperature

  3. Ultrafast x-ray-induced nuclear dynamics in diatomic molecules using femtosecond x-ray-pump-x-ray-probe spectroscopy

    Science.gov (United States)

    Lehmann, C. S.; Picón, A.; Bostedt, C.; Rudenko, A.; Marinelli, A.; Moonshiram, D.; Osipov, T.; Rolles, D.; Berrah, N.; Bomme, C.; Bucher, M.; Doumy, G.; Erk, B.; Ferguson, K. R.; Gorkhover, T.; Ho, P. J.; Kanter, E. P.; Krässig, B.; Krzywinski, J.; Lutman, A. A.; March, A. M.; Ray, D.; Young, L.; Pratt, S. T.; Southworth, S. H.

    2016-07-01

    The capability of generating two intense, femtosecond x-ray pulses with a controlled time delay opens the possibility of performing time-resolved experiments for x-ray-induced phenomena. We have applied this capability to study the photoinduced dynamics in diatomic molecules. In molecules composed of low-Z elements, K -shell ionization creates a core-hole state in which the main decay mode is an Auger process involving two electrons in the valence shell. After Auger decay, the nuclear wave packets of the transient two-valence-hole states continue evolving on the femtosecond time scale, leading either to separated atomic ions or long-lived quasibound states. By using an x-ray pump and an x-ray probe pulse tuned above the K -shell ionization threshold of the nitrogen molecule, we are able to observe ion dissociation in progress by measuring the time-dependent kinetic energy releases of different breakup channels. We simulated the measurements on N2 with a molecular dynamics model that accounts for K -shell ionization, Auger decay, and the time evolution of the nuclear wave packets. In addition to explaining the time-dependent feature in the measured kinetic energy release distributions from the dissociative states, the simulation also reveals the contributions of quasibound states.

  4. Kinematics of Compton backscattering x-ray source for angiography

    Energy Technology Data Exchange (ETDEWEB)

    Blumberg, L.N.

    1992-05-01

    Calculations of X-Ray production rates, energy spread, and spectrum of Compton-backscattered photons from a Free Electron Laser on an electron beam in a low energy (136-MeV) compact (8.5-m circumference) storage ring indicate that an X-Ray intensity of 34.6 10{sup 7} X-Ray photons per 0.5-mm {times} 0.5-mm pixel for Coronary Angiography near the 33.169-keV iodine K-absorption edge can be achieved in a 4-msec pulse within a scattering cone of 1-mrad half angle. This intensity, at 10-m from the photon-electron interaction point to the patient is about a factor of 10 larger than presently achieved from a 4.5-T superconducting wiggler source in the NSLS 2.5-GeV storage ring and over an area about 5 times larger. The 2.2-keV energy spread of the Compton-backscattered beam is, however, much larger than the 70-eV spread presently attained form the wiggler source and use of a monochromator. The beam spot at the 10-m interaction point-to-patient distance is 20-mm diameter; larger spots are attainable at larger distances but with a corresponding reduction in X-Ray flux. Such a facility could be an inexpensive clinical alternative to present methods of non-invasive Digital Subtraction Angiography (DSA), small enough to be deployed in an urban medical center, and could have other medical, industrial and aerospace applications. Problems with the Compton backscattering source include laser beam heating of the mirror in the FEL oscillator optical cavity, achieving a large enough X-Ray beam spot at the patient, and obtaining radiation damping of the transverse oscillations and longitudinal emittance dilution of the storage ring electron beam resulting from photon-electron collisions without going to higher electron energy where the X-Ray energy spread becomes excessive for DSA. 38 refs.

  5. [X-ray diagnostic of partial intestinal obstruction in small intestine diseases: a glance on the problem of radiologist-gastroenterologist].

    Science.gov (United States)

    Levchenko, S V; Kotovshchikova, A A; Orlova, N V

    2013-01-01

    The article is devoted to special features of X-ray examining of patients suffering from acute abdomen pain and X-ray paradigma of some intestine diseases as a cause of partial bowel obstruction. Own clinical data are presented. Long-term experience of our X-ray department is summarized. The possibilities of X-ray examining of abdomen with and without contrast in patients with partial bowel obstruction are described. PMID:24772872

  6. [X-ray diagnostic of partial intestinal obstruction in small intestine diseases: a glance on the problem of radiologist-gastroenterologist].

    Science.gov (United States)

    Levchenko, S V; Kotovshchikova, A A; Orlova, N V

    2013-01-01

    The article is devoted to special features of X-ray examining of patients suffering from acute abdomen pain and X-ray paradigma of some intestine diseases as a cause of partial bowel obstruction. Own clinical data are presented. Long-term experience of our X-ray department is summarized. The possibilities of X-ray examining of abdomen with and without contrast in patients with partial bowel obstruction are described.

  7. Hybrid x-ray/optical luminescence imaging: Characterization of experimental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, C. M.; Sun, C.; Pratx, G.; Rao, R.; Xing, L. [Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California 94305 (United States); SRI International, Menlo Park, California 94025 (United States); Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, California 94305 (United States)

    2010-08-15

    Purpose: The feasibility of x-ray luminescence imaging is investigated using a dual-modality imaging system that merges x-ray and optical imaging. This modality utilizes x-ray activated nanophosphors that luminesce when excited by ionizing photons. By doping phosphors with lanthanides, which emit light in the visible and near infrared range, the luminescence is suitable for biological applications. This study examines practical aspects of this new modality including phosphor concentration, light emission linearity, detector damage, and spectral emission characteristics. Finally, the contrast produced by these phosphors is compared to that of x-ray fluoroscopy. Methods: Gadolinium and lanthanum oxysulfide phosphors doped with terbium (green emission) or europium (red emission) were studied. The light emission was imaged in a clinical x-ray scanner with a cooled CCD camera and a spectrophotometer; dose measurements were determined with a calibrated dosimeter. Using these properties, in addition to luminescence efficiency values found in the literature for a similar phosphor, minimum concentration calculations are performed. Finally, a 2.5 cm agar phantom with a 1 cm diameter cylindrical phosphor-filled inclusion (diluted at 10 mg/ml) is imaged to compare x-ray luminescence contrast with x-ray fluoroscopic contrast at a superficial location. Results: Dose to the CCD camera in the chosen imaging geometry was measured at less than 0.02 cGy/s. Emitted light was found to be linear with dose (R{sup 2}=1) and concentration (R{sup 2}=1). Emission peaks for clinical x-ray energies are less than 3 nm full width at half maximum, as expected from lanthanide dopants. The minimum practical concentration necessary to detect luminescent phosphors is dependent on dose; it is estimated that subpicomolar concentrations are detectable at the surface of the tissue with typical mammographic doses, with the minimum detectable concentration increasing with depth and decreasing with dose. In

  8. Digital X-ray imager

    International Nuclear Information System (INIS)

    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

  9. X-ray shout echoing through space

    Science.gov (United States)

    2004-01-01

    a flash of X-rays hi-res Size hi-res: 3991 Kb Credits: ESA, S. Vaughan (University of Leicester) EPIC camera shows the expanding rings caused by a flash of X-rays XMM-Newton's X-ray EPIC camera shows the expanding rings caused by a flash of X-rays scattered by dust in our Galaxy. The X-rays were produced by a powerful gamma-ray burst that took place on 3 December 2003. The slowly fading afterglow of the gamma-ray burst is at the centre of the expanding rings. Other, unrelated, X-ray sources can also be seen. The time since the gamma-ray explosion is shown in each panel in hours. At their largest size, the rings would appear in the sky about five times smaller than the full moon. a flash of X-rays hi-res Size hi-res: 2153 Kb Credits: ESA, S. Vaughan (University of Leicester) EPIC camera shows the expanding rings caused by a flash of X-rays (Please choose "hi-res" version for animation) XMM-Newton's X-ray EPIC camera shows the expanding rings caused by a flash of X-rays scattered by dust in our Galaxy. The X-rays were produced by a powerful gamma-ray burst that took place on 3 December 2003. The slowly fading afterglow of the gamma-ray burst is at the centre of the expanding rings. Other, unrelated, X-ray sources can also be seen. The time since the gamma-ray explosion is shown in each panel in seconds. At their largest size, the rings would appear in the sky about five times smaller than the full moon. This echo forms when the powerful radiation of a gamma-ray burst, coming from far away, crosses a slab of dust in our Galaxy and is scattered by it, like the beam of a lighthouse in clouds. Using the expanding rings to precisely pin-point the location of this dust, astronomers can identify places where new stars and planets are likely to form. On 3 December 2003 ESA's observatory, Integral, detected a burst of gamma rays, lasting about 30 seconds, from the direction of a distant galaxy. Within minutes of the detection, thanks to a sophisticated alert network, many

  10. Radiation hygiene aspects of dental X-ray diagnosis

    International Nuclear Information System (INIS)

    The dental X-rays are among the most frequent types of X-ray examinations performed in Bulgaria. Over the past decade, the share of these investigations has ranged from 20 to 30% of all X-rays performed in the country. This communication considers the following radiation-health problems involved in dental X-ray diagnosis: frequency of dental X-ray examinations and the contribution of the standard and nonstandard examinations towards radiation doses received by patients. (author)

  11. An X-ray and optical study of the ultracompact X-ray binary A 1246-58

    NARCIS (Netherlands)

    in 't Zand, J. J. M.; Bassa, C. G.; Keek, L.; Verbunt, F.; Mendez, M.; Markwardt, C. B.; Jonker, P.G.

    2008-01-01

    Results are discussed of an X-ray and optical observation campaign of the low-mass X-ray binary A 1246-58 performed with instruments on Satellite per Astronomia X ("BeppoSAX"), the Rossi X-ray Timing Explorer (RXTE), the X-ray Multi-mirror Mission ("XMM-Newton"), the Swift mission, and the Very Larg

  12. An X-ray and optical study of the ultracompact X-ray binary A1246-58

    NARCIS (Netherlands)

    Zand, J. J. M. in 't

    2008-01-01

    Results are discussed of an X-ray and optical observation campaign of the low-mass X-ray binary A 1246-58 performed with instruments on Satellite per Astronomia X (’BeppoSAX’), the Rossi X-ray Timing Explorer (RXTE), the X-ray Multi-mirror Mission (’XMM-Newton’), the Swift mission, and the Very Larg

  13. 乳腺癌诊断中超声和X线钼靶诊断的临床价值分析%Ultrasound in the Diagnosis of Breast Cancer and Clinical Value of X-ray Mammography in the Diagnosis of Analysis

    Institute of Scientific and Technical Information of China (English)

    唐益君; 鹿文静; 韩江涛

    2014-01-01

    Objective To investigate the clinical value of the diagnosis of breast cancer X-ray mammography and ultrasound diagnostics.Methods In our hospital in January 2013~December were treated with ultrasound and X-ray mammography and were confirmed by surgery and pathology confirmed 50 cases of breast cancer patients for the study,the clinical imaging data were analyzed retrospectively.Results Diagnostic ultrasound and surgical pathology diagnosis was 88.0%, X-ray mammography diagnosis was 70.0%;combined diagnostic ultrasound and mammography X-ray coincidence rate was 92.0%.Conclusion Breast cancer diagnosis,ultrasound combined with X-ray mammography diagnosis rate is higher,ultrasound diagnosis rate is slightly higher than X-ray mammography diagnosis,the combined diagnosis of breast cancer can significantly improve the detection rate and the ability to identify with high practical value.%目的:探讨分析乳腺癌诊断中超声和X线钼靶诊断的临床价值。方法选取我院2013年1月~12月收治的行超声和X线钼靶检查且均经手术及病理学证实的50例乳腺癌患者为研究对象,对其临床影像资料进行回顾性分析。结果超声诊断与手术病理诊断符合率为88.0%,X线钼靶诊断符合率为70.0%;超声和X线钼靶联合诊断符合率为92.0%。结论乳腺癌诊断中,超声联合X线钼靶诊断符合率较高,超声诊断符合率略高于X线钼靶诊断,故联合诊断能明显提高乳腺癌的检出率及鉴别能力,具有较高的实用价值。

  14. Closed-bore XMR (CBXMR) systems for aortic valve replacement: X-ray tube imaging performance

    Energy Technology Data Exchange (ETDEWEB)

    Bracken, John A.; Komljenovic, Philip; Lillaney, Prasheel V.; Fahrig, Rebecca; Rowlands, J. A. [Department of Medical Biophysics and Sunnybrook Health Sciences Center, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 (Canada); Department of Radiology, Stanford University, Stanford, California 94305 (United States); Department of Medical Biophysics and Sunnybrook Health Sciences Center, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 (Canada)

    2009-04-15

    A hybrid closed-bore x-ray/MRI system (CBXMR) is proposed to improve the safety and efficacy of percutaneous aortic valve replacement procedures. In this system, an x-ray C-arm will be positioned about 1 m from the entrance of a 1.5 T MRI scanner. The CBXMR system will harness the complementary strengths of both modalities to guide and deploy a bioprosthetic valve into the aortic annulus of the heart without coronary artery obstruction. A major challenge in constructing this system is ensuring proper operation of a rotating-anode x-ray tube in the MRI magnetic fringe field environment. The electron beam in the x-ray tube responsible for producing x rays can be deflected by the fringe field. However, the clinical impact of electron beam deflection in a magnetic field has not yet been studied. Here, the authors investigated changes in focal spot resolving power, field of view shift, and field of view truncation in x-ray images as a result of electron beam deflection. The authors found that in the fringe field acting on the x-ray tube at the clinical location for the x-ray C-arm (4 mT), focal spot size increased by only 2%, so the fringe field did not limit the resolving power of the x-ray system. The magnetic field also caused the field of view to shift by 3 mm. This shift must be corrected to avoid unnecessary primary radiation exposure to the patient and the staff in the cardiac catheterization laboratory. The fringe field was too weak to cause field of view truncation.

  15. Closed-bore XMR (CBXMR) systems for aortic valve replacement: x-ray tube imaging performance.

    Science.gov (United States)

    Bracken, John A; Komljenovic, Philip; Lillaney, Prasheel V; Fahrig, Rebecca; Rowlands, J A

    2009-04-01

    A hybrid closed-bore x-ray/MRI system (CBXMR) is proposed to improve the safety and efficacy of percutaneous aortic valve replacement procedures. In this system, an x-ray C-arm will be positioned about 1 m from the entrance of a 1.5 T MRI scanner. The CBXMR system will harness the complementary strengths of both modalities to guide and deploy a bioprosthetic valve into the aortic annulus of the heart without coronary artery obstruction. A major challenge in constructing this system is ensuring proper operation of a rotating-anode x-ray tube in the MRI magnetic fringe field environment. The electron beam in the x-ray tube responsible for producing x rays can be deflected by the fringe field. However, the clinical impact of electron beam deflection in a magnetic field has not yet been studied. Here, the authors investigated changes in focal spot resolving power, field of view shift, and field of view truncation in x-ray images as a result of electron beam deflection. The authors found that in the fringe field acting on the x-ray tube at the clinical location for the x-ray C-arm (4 mT), focal spot size increased by only 2%, so the fringe field did not limit the resolving power of the x-ray system. The magnetic field also caused the field of view to shift by 3 mm. This shift must be corrected to avoid unnecessary primary radiation exposure to the patient and the staff in the cardiac catheterization laboratory. The fringe field was too weak to cause field of view truncation. PMID:19472613

  16. X-ray Chirped Pulse Amplification: towards GW Soft X-ray Lasers

    Directory of Open Access Journals (Sweden)

    Marta Fajardo

    2013-07-01

    Full Text Available Extensive modeling of the seeding of plasma-based soft X-ray lasers is reported in this article. Seminal experiments on amplification in plasmas created from solids have been studied in detail and explained. Using a transient collisional excitation scheme, we show that a 18 µJ, 80 fs fully coherent pulse is achievable by using plasmas pumped by a compact 10 Hz laser. We demonstrate that direct seeding of plasmas created by nanosecond lasers is not efficient. Therefore, we propose and fully study the transposition to soft X-rays of the Chirped Pulse Amplification (CPA technique. Soft X-ray pulses with energy of 6 mJ and 200 fs duration are reachable by seeding plasmas pumped by compact 100 J, sub-ns, 1 shot/min lasers. These soft X-ray lasers would reach GW power, corresponding to an increase of 100 times as compared to the highest peak power achievable nowadays in the soft X-ray region (30 eV–1 keV. X-ray CPA is opening new horizon for soft x-ray ultra-intense sources.

  17. Demonstration of x-ray holography with an x-ray laser

    International Nuclear Information System (INIS)

    X-ray holography offers the potential for obtaining high resolution three-dimensional images of in vitro biological microstructures. Significant progress toward this goal has been achieved with holography systems using synchrotron x-ray sources and recently spatial resolutions as small as 40 nm have been demonstrated. These experiments required x-ray exposures of an hour or longer, which makes high spatial resolution difficult to achieve in live biological specimens because of blurring of the image. This blurring is caused by specimen motion and prohibits the imaging of dynamical processes within the specimen. A possible solution to this problem is to exploit the extremely high brightness and long coherence lengths produced by x-ray lasers and create the hologram with exposure times of less than 1 nsec. This report presents the results from an experiment in which an x-ray laser was used to produce x-ray holograms. The holography geometry used was a Gabor in-line type modified by the inclusion of a high reflectivity multi-layer x-ray mirror used as a narrow bandpass filter

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

    OpenAIRE

    Toru Aoki; Takuya Nakashima; Hisashi Morii; Yoichiro Neo; Hidenori Mimura

    2008-01-01

    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 C...

  19. On the X-ray properties of V Sge and its relation to the supersoft X-ray binaries

    OpenAIRE

    Greiner, Jochen; van Teeseling, Andre

    1998-01-01

    We investigate the ROSAT X-ray properties of V Sge, which has been proposed to be related to supersoft X-ray binaries. During optical bright states, V Sge is a faint hard X-ray source, while during optical faint states (V >=12 mag), V Sge is a `supersoft' X-ray source. Spectral fitting confirms that V~Sge's X-ray properties during its soft X-ray state may be similar to those of supersoft X-ray binaries, although a much lower luminosity cannot be excluded. It is possible to explain the differe...

  20. X-ray microtomography of bones and teeth.

    Science.gov (United States)

    Davis, G R; Wong, F S

    1996-08-01

    X-ray microtomography is a miniaturized version of computerized axial tomography with a resolution of the order of micrometres. In the biomedical field it is particularly useful in the study of hard tissue because of its ability to accurately measure the linear attenuation coefficient. From this, the mineral concentration can be computed, which is one measure of bone quality. Using microtomography it is also possible to form three-dimensional images of bone from which structural parameters can be derived which could not be measured using conventional histomorphometry. Various types of microtomography scanner have been used, including simple translate-rotate systems which are capable of measuring x-ray attenuation at multiple energies simultaneously, and "cone-beam' systems which can acquire the necessary data for three-dimensional reconstructions in a relatively short time. Both laboratory x-ray sources and synchrotrons have been used in the study of hard tissue using microtomography. Most studies of bone have been concerned primarily with either the mineral concentration in cortical bone or the structure in cancellous bone. The mineral concentration in teeth has also been studied, in particular the loss of mineral in enamel during in vitro demineralization and the gain during subsequent remineralization. Although there are currently relatively few centres carrying out this work, interest in the technique is rapidly growing and it is likely to find a useful place both in research and ultimately in clinical practice.

  1. Controlled Use of X-Ray in Dental Practice

    Directory of Open Access Journals (Sweden)

    Lesbia Rosa Tirado-Amado

    2015-01-01

    Full Text Available Abstract: Objective: To contribute in an informative and critical way to the promotion of controlled use of X-ray during dental consulting and dental care. Introduction: The practice of dentistry as a health care service requires the use of complementary tools for proper diagnosis, treatment and follow-up in patients with different clinical conditions. For that reason, the use of x-ray by dentists is common and very useful, but it involves radiation exposure to the patient and the dental professional or dental student. Although, often people do not pay attention to this exposition in regard to biological effects, because they are considered too low to generate significant biological effects. Conclusion: It is necessary to consider the risk of accumulative doses for constant exposure in dentist and dental students. Moreover, in patients, because a synergism with other radiations can occur, they can be exposed because of the attention in other areas of health. For these reasons, it is necessary to promote awareness and knowledge on basic aspects of the controlled use of X-ray in the dental care, being also aware of the need to strengthen the knowledge of the basics aspects that lead to decreased risk of biological effects from its proper use in the dental care.

  2. X-ray spectroscopy: Enlightened state

    Science.gov (United States)

    McCusker, James K.

    2014-07-01

    Determining the sequence of events following photon absorption by a molecule can be a surprisingly challenging task. An innovative use of time-resolved X-ray spectroscopy has revealed an important insight into the ultrafast excited-state dynamics of a well-known inorganic chromophore.

  3. X-rays from neutron stars

    International Nuclear Information System (INIS)

    The basic theoretical in the models of regularly pulsating X-ray sources are discussed, and put in relation to the observations. The topics covered include physics of the magnetosphere of an accreting neutron star, hydrodynamics of the accretion column, physical processes close to the surface of the neutron star such as proton-electron collisions, photon-electron interactions. (orig.)

  4. Neutron and X-ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Carini, Gabriella [SLAC National Accelerator Lab., Menlo Park, CA (United States); Denes, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gruener, Sol [Cornell Univ., Ithaca, NY (United States); Lessner, Elianne [Dept. of Energy (DOE), Washington DC (United States). Office of Science Office of Basic Energy Sciences

    2012-08-01

    The Basic Energy Sciences (BES) X-ray and neutron user facilities attract more than 12,000 researchers each year to perform cutting-edge science at these state-of-the-art sources. While impressive breakthroughs in X-ray and neutron sources give us the powerful illumination needed to peer into the nano- to mesoscale world, a stumbling block continues to be the distinct lag in detector development, which is slowing progress toward data collection and analysis. Urgently needed detector improvements would reveal chemical composition and bonding in 3-D and in real time, allow researchers to watch “movies” of essential life processes as they happen, and make much more efficient use of every X-ray and neutron produced by the source The immense scientific potential that will come from better detectors has triggered worldwide activity in this area. Europe in particular has made impressive strides, outpacing the United States on several fronts. Maintaining a vital U.S. leadership in this key research endeavor will require targeted investments in detector R&D and infrastructure. To clarify the gap between detector development and source advances, and to identify opportunities to maximize the scientific impact of BES user facilities, a workshop on Neutron and X-ray Detectors was held August 1-3, 2012, in Gaithersburg, Maryland. Participants from universities, national laboratories, and commercial organizations from the United States and around the globe participated in plenary sessions, breakout groups, and joint open-discussion summary sessions. Sources have become immensely more powerful and are now brighter (more particles focused onto the sample per second) and more precise (higher spatial, spectral, and temporal resolution). To fully utilize these source advances, detectors must become faster, more efficient, and more discriminating. In supporting the mission of today’s cutting-edge neutron and X-ray sources, the workshop identified six detector research challenges

  5. X-ray lasers at MBI

    Science.gov (United States)

    Janulewicz, Karol A.; Lucianetti, Antonio; Priebe, Gerd; Sandner, Wolfgang; Nickles, Peter-Viktor

    2003-10-01

    The state-of-the-art and the trends in development of table-top soft x-ray lasers (XRLs) with a special emphasis on the work of the Max Born Institute (MBI) are presented. Both, basic physics and some features of the output radiation crucial for applications are discussed as well.

  6. Magnetic X-ray diffraction from samarium

    Energy Technology Data Exchange (ETDEWEB)

    Watson, D. [School of Physics and Space Research, University of Birmingham, Birmingham B15 2TT (United Kingdom); Forgan, E.M. [School of Physics and Space Research, University of Birmingham, Birmingham B15 2TT (United Kingdom); Stirling, W.G. [Department of Physics, University of Keele, Keele, Staffs ST5 5BG (United Kingdom); Nuttall, W.J. [Department of Physics, University of Keele, Keele, Staffs ST5 5BG (United Kingdom); Perry, S.C. [Department of Physics, University of Keele, Keele, Staffs ST5 5BG (United Kingdom); Costa, M.M.R. [Physics Department, Universidade de Coimbra, 3000 Coimbra (Portugal); Fort, D. [School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    1995-02-09

    We report X-ray scattering observations on antiferromagnetic samarium, using the NSLS synchrotron source. We have made new observations of the absorption-corrected energy dependence and temperature variation of the resonantly enhanced magnetic signal from the hexagonal sites near the L{sub III} edge. ((orig.)).

  7. Skull X-Rays for Head Injury

    OpenAIRE

    J Gordon Millichap

    2005-01-01

    The effect of abolishing skull X-rays on the rate of admission, use of computer tomography (CT), radiation dose per head injury, and detection of intracranial injuries was determined in patients, aged 1 to 14 years, presenting to the ED at Royal Hospital for Sick Children, Edinburgh, UK.

  8. Femtosecond X-ray protein nanocrystallography

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Henry N. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; Univ. of Hamburg (Germany); Barty, Anton [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; White, Thomas A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; Aquila, Andrew [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; Schulz, Joachim [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; DePonte, Daniel P. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; Martin, Andrew V. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; Coppola, Nicola [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; Liang, Mengning [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; Caleman, Carl [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; Gumprecht, Lars [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; Stern, Stephan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science; Nass, Karol [Univ. of Hamburg (Germany); Fromme, Petra [Arizona State Univ., Tempe, AZ (United States). Dept. of Chemistry and Biochemistry; Hunter, Mark S. [Arizona State Univ., Tempe, AZ (United States). Dept. of Chemistry and Biochemistry; Grotjohann, Ingo [Arizona State Univ., Tempe, AZ (United States). Dept. of Chemistry and Biochemistry; Fromme, Raimund [Arizona State Univ., Tempe, AZ (United States). Dept. of Chemistry and Biochemistry; Kirian, Richard A. [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics; Weierstall, Uwe [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics; Doak, R. Bruce [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics; Schmidt, Kevin E. [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics; Wang, Xiaoyu [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics; Spence, John C. H. [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics; Schlichting, Ilme [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science, Max Planck Advanced Study Group; Max Planck Inst. fur Medizinische Forschung, Heidelberg (Germany); Epp, Sascha W. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science, Max Planck Advanced Study Group; Max Planck Inst. fur Kernphysik, Heidelberg (Germany); Rolles, Daniel [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science, Max Planck Advanced Study Group; Max Planck Inst. fur Medizinische Forschung, Heidelberg (Germany); Rudenko, Artem [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science, Max Planck Advanced Study Group; Max Planck Inst. fur Kernphysik, Heidelberg (Germany); Foucar, Lutz [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science, Max Planck Advanced Study Group; Max Planck Inst. fur Medizinische Forschung, Heidelberg (Germany); Rudek, Benedikt [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science, Max Planck Advanced Study Group; Max Planck Inst. fur Kernphysik, Heidelberg (Germany); Erk, Benjamin [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science, Max Planck Advanced Study Group; Max Planck Inst. fur Kernphysik, Heidelberg (Germany); Schmidt, Carlo [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science, Max Planck Advanced Study Group; Max Planck Inst. fur Kernphysik, Heidelberg (Germany); Hömke, André [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science, Max Planck Advanced Study Group; Max Planck Inst. fur Kernphysik, Heidelberg (Germany); Strüder, Lothar [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science, Max Planck Advanced Study Group; Max Planck Society Semiconductor Lab., Munich (Germany); Ullrich, Joachim [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science, Max Planck Advanced Study Group; Max Planck Inst. fur Kernphysik, Heidelberg (Germany); Krasniqi, Faton [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Center for Free-Electron Laser Science, Max Planck Advanced Study Group; Max Planck Inst. fur Medizinische Forschung, Heidelberg (Germany); Lomb, Lukas [Max Planck Inst. fur Medizinische Forschung, Heidelberg (Germany); Shoeman, Robert L. [Max Planck Inst. fur Medizinische Forschung, Heidelberg (Germany); Bott, Mario [Max Planck Inst. fur Medizinische Forschung, Heidelberg (Germany); Barends, Thomas R. M. [Max Planck Inst. fur Medizinische Forschung, Heidelberg (Germany); Kuhnel, Kai-Uwe [Max Planck Inst. fur Kernphysik, Heidelberg (Germany); Schroter, Claus-Dieter [Max Planck Inst. fur Kernphysik, Heidelberg (Germany); Hartmann, Robert [PNSensor GmbH, Munich (Germany); Holl, Peter [PNSensor GmbH, Munich (Germany); Reich, Christian [PNSensor GmbH, Munich (Germany); Soltau, Heike [PNSensor GmbH, Munich (Germany); Kimmel, Nils [Max Planck Society Semiconductor Lab., Munich (Germany); Weidenspointner, Georg [Max Planck Society Semiconductor Lab., Munich (Germany); Max Planck Inst. fur Extraterrestrische Physik, Garching (Germany); Pietschner, Daniel [Max Planck Society Semiconductor Lab., Munich (Germany); Hauser, Günter [Max Planck Society Semiconductor Lab., Munich (Germany); Herrmann, Sven [Max Planck Society Semiconductor Lab., Munich (Germany); Schaller, Gerhard [Max Planck Society Semiconductor Lab., Munich (Germany); Schopper, Florian [Max Planck Society Semiconductor Lab., Munich (Germany); Andritschke, Robert [Max Planck Society Semiconductor Lab., Munich (Germany); Boutet, Sébastien [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source (LCLS); Krzywinski, Jacek [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source (LCLS); Bostedt, Christoph [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source (LCLS); Messerschmidt, Marc [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source (LCLS); Bozek, John D. [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source (LCLS); Williams, Garth J. [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source (LCLS); Bogan, Michael J. [SLAC National Accelerator Lab., Menlo Park, CA (United States). Photon Ultrafast Laser Science and Engineering Inst. (PULSE); Hampton, Christina Y. [SLAC National Accelerator Lab., Menlo Park, CA (United States). Photon Ultrafast Laser Science and Engineering Inst. (PULSE); Sierra, Raymond G. [SLAC National Accelerator Lab., Menlo Park, CA (United States). Photon Ultrafast Laser Science and Engineering Inst. (PULSE); Starodub, Dmitri [SLAC National Accelerator Lab., Menlo Park, CA (United States). Photon Ultrafast Laser Science and Engineering Inst. (PULSE); Gorke, Hubert [Forschungszentrum Julich (Germany); Hau-Riege, Stefan P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Frank, Matthias [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Maia, Filipe R. N. C. [Uppsala Univ. (Sweden). Dept. of Cell and Molecular Biology, Lab. of Molecular Biophysics; Hajdu, Janos [Uppsala Univ. (Sweden). Dept. of Cell and Molecular Biology, Lab. of Molecular Biophysics; Timneanu, Nicusor [Uppsala Univ. (Sweden). Dept. of Cell and Molecular Biology, Lab. of Molecular Biophysics; Seibert, M. Marvin [Uppsala Univ. (Sweden). Dept. of Cell and Molecular Biology, Lab. of Molecular Biophysics; Andreasson, Jakob [Uppsala Univ. (Sweden). Dept. of Cell and Molecular Biology, Lab. of Molecular Biophysics; Rocker, Andrea [Uppsala Univ. (Sweden). Dept. of Cell and Molecular Biology, Lab. of Molecular Biophysics; Jönsson, Olof [Uppsala Univ. (Sweden). Dept. of Cell and Molecular Biology, Lab. of Molecular Biophysics; Svenda, Martin [Uppsala Univ. (Sweden). Dept. of Cell and Molecular Biology, Lab. of Molecular Biophysics; Holton, James M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); Marchesini, Stefano [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); Neutze, Richard [Univ. of Gothenburg (Sweden). Dept. of Chemistry, Biochemistry and Biophysics; Schorb, Sebastian [Technische Univ. Berlin (Germany). Inst. fur Optik und Atomare Physik (IOAP); Rupp, Daniela [Technische Univ. Berlin (Germany). Inst. fur Optik und Atomare Physik (IOAP); Adolph, Marcus [Technische Univ. Berlin (Germany). Inst. fur Optik und Atomare Physik (IOAP); Gorkhover, Tais [Technische Univ. Berlin (Germany). Inst. fur Optik und Atomare Physik (IOAP); Andersson, Inger [Swedish Univ. of Agricultural Sciences, Uppsala Biomedical Centre, Uppsala, (Sweden). Dept. of Molecular Biology; Barthelmess, Miriam [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Photon Science; Bajt, Saša [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Photon Science; Hirsemann, Helmut [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Photon Science; Potdevin, Guillaume [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Photon Science; Graafsma, Heinz [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Photon Science; Nilsson, Björn [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Photon Science

    2011-02-03

    X-ray crystallography provides the vast majority of macromolecular structures, but the success of the method relies on growing crystals of sufficient size. In conventional measurements, the necessary increase in X-ray dose to record data from crystals that are too small leads to extensive damage before a diffraction signal can be recorded. It is particularly challenging to obtain large, well-diffracting crystals of membrane proteins, for which fewer than 300 unique structures have been determined despite their importance in all living cells. Here we present a method for structure determination where single-crystal X-ray diffraction ‘snapshots’ are collected from a fully hydrated stream of nanocrystals using femtosecond pulses from a hard-X-ray free-electron laser, the Linac Coherent Light Source. We prove this concept with nanocrystals of photosystem I, one of the largest membrane protein complexes. More than 3,000,000 diffraction patterns were collected in this study, and a three-dimensional data set was assembled from individual photosystem I nanocrystals (~200 nm to 2 μm in size). We mitigate the problem of radiation damage in crystallography by using pulses briefer than the timescale of most damage processes. This offers a new approach to structure determination of macromolecules that do not yield crystals of sufficient size for studies using conventional radiation sources or are particularly sensitive to radiation damage.

  9. X-ray optics for axion helioscopes

    DEFF Research Database (Denmark)

    Jakobsen, Anders Clemen; Pivovaroff, Michael J.; Christensen, Finn Erland

    2013-01-01

    A method of optimizing grazing incidence x-ray coatings in ground based axion helioscopes is presented. Software has been been developed to find the optimum coating when taking both axion spectrum and Micromegas detector quantum efficiency into account. A comparison of the relative effective area...... of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only....

  10. Outbursts in ultracompact X-ray binaries

    CERN Document Server

    Hameury, J -M

    2016-01-01

    Very faint X-ray binaries appear to be transient in many cases with peak luminosities much fainter than that of usual soft X-ray transients, but their nature still remains elusive. We investigate the possibility that this transient behaviour is due to the same thermal/viscous instability which is responsible for outbursts of bright soft X-ray transients, occurring in ultracompact binaries for adequately low mass-transfer rates. More generally, we investigate the observational consequences of this instability when it occurs in ultracompact binaries. We use our code for modelling the thermal-viscous instability of the accretion disc, assumed here to be hydrogen poor. We also take into account the effects of disc X-ray irradiation, and consider the impact of the mass-transfer rate on the outburst brightness. We find that one can reproduce the observed properties of both the very faint and the brighter short transients (peak luminosity, duration, recurrence times), provided that the viscosity parameter in quiesce...

  11. X-ray lasers and crystallography

    OpenAIRE

    Spence, John C. H.

    2014-01-01

    The development of X-ray lasers and their applications in crystallography is described. In the birth of this new field, IUCrJ is ideally positioned to present this research to both specialists in crystallography, and to the wider audience in structural biology.

  12. Fourier techniques in X-ray timing

    NARCIS (Netherlands)

    M. van der Klis

    1988-01-01

    Basic principles of Fourier techniques often used in X-ray time series analysis are reviewed. The relation between the discrete Fourier transform and the continuous Fourier transform is discussed to introduce the concepts of windowing and aliasing. The relation is derived between the power spectrum

  13. Exploring subluminous X-ray binaries

    NARCIS (Netherlands)

    N.D. Degenaar

    2010-01-01

    Halfway the twentieth century, technological developments made it possible to carry detection instruments outside the absorbing layers of the Earth’s atmosphere onboard rockets and satellites. This opened up the opportunity to detect the emission from celestial objects at X-ray wavelengths, thereby

  14. X-ray voltabsorptometry on redox proteins

    Energy Technology Data Exchange (ETDEWEB)

    Ascone, Isabella [Dipartimento di Fisica, Universita di Roma ' La Sapienza' , P.le A. Moro 5, 00185 Rome (Italy) and LURE/CNRS Centre Universitaire Paris-Sud, bat. 209 D, B.P. 34, 91898 Orsay Cedex (France)]. E-mail: i.ascone@caspur.it; Zamponi, Silvia [Dipartimento di Scienze Chimiche, Universita di Camerino, Via S. Agostino 1, 62032 Camerino (Italy); Cognigni, Andrea [LURE/CNRS Centre Universitaire Paris-Sud, bat. 209 D, B.P. 34, 91898 Orsay Cedex (France); Marmocchi, Franco [Dipartimento di Biologia Molecolare, Cellulare e Animale, Universita di Camerino, Via Camerini, 1 Camerino (Italy); Marassi, Roberto [Dipartimento di Scienze Chimiche, Universita di Camerino, Via S. Agostino 1, 62032 Camerino (Italy)

    2005-04-15

    Biological X-ray absorption spectroscopy (BioXAS) is able to describe the metal environment in a metalloprotein and is sensitive to metal oxidation state. Coupling of BioXAS and electrochemistry permits the characterization of different oxidation states and avoids uncontrolled protein redox state changes due to X-ray beam irradiation. XAS spectroelectrochemistry requires electrochemical cells specifically designed to meet the requirements of both XAS measurements and electrochemical effectiveness in potential control. In this context, this paper describes a new cell tested with different types of working electrodes developed for BioXAS, in particular for in situ studies of redox proteins. The XAS electrochemical measurements of a relatively high-molecular-weight protein (Cu,Zn superoxide dismutase) for which it is difficult to observe direct electrochemistry have been achieved. New working electrodes, capable of fast and unmediated electron transfer, are described. The cell permits to isolate protein redox states and to measure X-ray absorption intensity during a potential scan (X-ray voltabsorptometry)

  15. Soft x-ray laser microscope

    Energy Technology Data Exchange (ETDEWEB)

    Suckewer, P.I.

    1990-10-01

    The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL's 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si[sub 3]N[sub 4]) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.

  16. Compact stellar X-ray sources

    NARCIS (Netherlands)

    W.H.G. Lewin; M. van der Klis

    2006-01-01

    X-ray astronomy is the prime available window on astrophysical compact objects: black holes, neutron stars and white dwarfs. In the last ten years new observational opportunities have led to an explosion of knowledge in this field. This book provides a comprehensive overview of the astrophysics of c

  17. X-ray signals in renal osteopathy

    Energy Technology Data Exchange (ETDEWEB)

    Rieden, K.

    1984-10-01

    Chronic renal insufficiency is associated with metabolic disturbances which ultimately lead to typical, partly extremely painful changes in the skeletal system the longer the disease persists. Regular X-ray control of certain skeletal segments allows early detection of renal oesteopathy if the radiological findings described in this article are carefully scrutinised and interpreted.

  18. X-ray microscopy of human malaria

    Energy Technology Data Exchange (ETDEWEB)

    Magowan, C.; Brown, J.T.; Mohandas, N.; Meyer-Ilse, W. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)

    1997-04-01

    Associations between intracellular organisms and host cells are complex and particularly difficult to examine. X-ray microscopy provides transmission images of subcellular structures in intact cells at resolutions superior to available methodologies. The spatial resolution is 50-60nm with a 1 micron depth of focus, superior to anything achievable with light microscopy. Image contrast is generated by differences in photoelectric absorption by the atoms in different areas (i.e. subcellular structures) throughout the full thickness of the sample. Absorption due to carbon dominates among all the elements in the sample at 2.4 nm x-ray wavelength. Thus images show features or structures, in a way not usually seen by other types of microscopy. The authors used soft x-ray microscopy to investigate structural development of Plasmodium falciparum malaria parasites in normal and genetically abnormal erythrocytes, and in infected erythrocytes treated with compounds that have anti-malarial effects. X-ray microscopy showed newly elaborated structures in the cytosol of unstained, intact erythrocytes, redistribution of mass (carbon) in infected erythrocytes, and aberrant parasite morphology. Better understanding of the process of intracellular parasite maturation and the interactions between the parasite and its host erythrocyte can help define new approaches to the control of this deadly disease.

  19. Massively parallel X-ray holography

    Energy Technology Data Exchange (ETDEWEB)

    Spence, John C.H [Arizona State University; Marchesini, Stefano [Lawrence Berkeley National Laboratory, Berkeley; Boutet, Sebastien [Stanford Synchrotron Radiation Laboratory; Sakdinawat, Anne E. [, Lawrence Berkeley National Laboratory; Bogan, Michael J. [Lawrence Livermore National Laboratory; Bajt, Sasa [Lawrence Livermore National Laboratory; Barty, Anton [Lawrence Livermore National Laboratory; Chapman, Henry N. [Lawrence Livermore National Laboratory; Frank, Matthias [Lawrence Livermore National Laboratory; Hau-Riege, Stefan P. [Lawrence Livermore National Laboratory; Szöke, Abraham [Lawrence Livermore National Laboratory; Cui, Congwu [Lawrence Berkeley National Laboratory; Shapiro, David A. [Lawrence Berkeley National Laboratory; Howells, MAlcolm R. [Lawrence Berkeley National Laboratory; Shaevitz, Joshua W [Lewis-Sigler Institute; Lee, Joanna Y. [University of California, Berkeley; Hajdu, Janos [3Stanford Synchrotron Radiation Laboratory; Seibert, Marvin M. [Uppsala University

    2008-08-01

    Advances in the development of free-electron lasers offer the realistic prospect of nanoscale imaging on the timescale of atomic motions. We identify X-ray Fourier-transform holography1,2,3 as a promising but, so far, inefficient scheme to do this. We show that a uniformly redundant array4 placed next to the sample, multiplies the efficiency of X-ray Fourier transform holography by more than three orders of magnitude, approaching that of a perfect lens, and provides holographic images with both amplitude- and phase-contrast information. The experiments reported here demonstrate this concept by imaging a nano-fabricated object at a synchrotron source, and a bacterial cell with a soft-X-ray free-electron laser, where illumination by a single 15-fs pulse was successfully used in producing the holographic image. As X-ray lasers move to shorter wavelengths we expect to obtain higher spatial resolution ultrafast movies of transient states of matter

  20. XRASE: The X-Ray Spectroscopic Explorer

    DEFF Research Database (Denmark)

    Schnopper, H.W.; Silver, E.; Murray, S.;

    2001-01-01

    eV at 6 keV) and efficiency with a field-of-view of 26 arcmin(2) . A deep orbit allows for long, continuous observations. Monitoring instruments in the optical (WOM-X), UV (TAUVEX) and hard X-RAY (GRAM) bands will offer exceptional opportunities to make simultaneous multi-wavelength observations....

  1. Supernova remnants: the X-ray perspective

    NARCIS (Netherlands)

    J. Vink

    2012-01-01

    Supernova remnants are beautiful astronomical objects that are also of high scientific interest, because they provide insights into supernova explosion mechanisms, and because they are the likely sources of Galactic cosmic rays. X-ray observations are an important means to study these objects. And i

  2. Harmonic lasing in X-ray FELs

    Energy Technology Data Exchange (ETDEWEB)

    Schneidmiller, E.A.; Yurkov, M.V.

    2012-05-15

    Harmonic lasing in a free electron laser with a planar undulator (under the condition that the fundamental frequency is suppressed) might be a cheap and efficient way of extension of wavelength ranges of existing and planned X-ray FEL facilities. Contrary to nonlinear harmonic generation, harmonic lasing can provide much more intense, stable, and narrow-band FEL beam which is easier to handle due to the suppressed fundamental frequency. In this paper we perform a parametrization of the solution of the eigenvalue equation for lasing at odd harmonics, and present an explicit expression for FEL gain length, taking into account all essential effects. We propose and discuss methods for suppression of the fundamental harmonic. We also suggest a combined use of harmonic lasing and lasing at the retuned fundamental wavelength in order to reduce bandwidth and to increase brilliance of X-ray beam at saturation. Considering 3rd harmonic lasing as a practical example, we come to the conclusion that it is much more robust than usually thought, and can be widely used in the existing or planned X-ray FEL facilities. In particular, LCLS after a minor modification can lase to saturation at the 3rd harmonic up to the photon energy of 25-30 keV providing multi-gigawatt power level and narrow bandwidth. As for the European XFEL, harmonic lasing would allow to extend operating range (ultimately up to 100 keV), to reduce FEL bandwidth and to increase brilliance, to enable two-color operation for pump-probe experiments, and to provide more flexible operation at different electron energies. Similar improvements can be realized in other X-ray FEL facilities with gap-tunable undulators like FLASH II, SACLA, LCLS II, etc. Harmonic lasing can be an attractive option for compact X-ray FELs (driven by electron beams with a relatively low energy), allowing the use of the standard undulator technology instead of small-gap in-vacuum devices. Finally, in this paper we discover that in a part of the

  3. Fourier transform based iterative method for x-ray differential phase-contrast computed tomography

    CERN Document Server

    Cong, Wenxiang; Wang, Ge

    2011-01-01

    Biological soft tissues encountered in clinical and pre-clinical imaging mainly consist of light element atoms, and their composition is nearly uniform with little density variation. Thus, x-ray attenuation imaging suffers from low image contrast resolution. By contrast, x-ray phase shift of soft tissues is about a thousand times greater than x-ray absorption over the diagnostic energy range, thereby a significantly higher sensitivity can be achieved in terms of phase shift. In this paper, we propose a novel Fourier transform based iterative method to perform x-ray tomographic imaging of the refractive index directly from differential phase shift data. This approach offers distinct advantages in cases of incomplete and noisy data than analytic reconstruction, and especially suitable for phase-contrast interior tomography by incorporating prior knowledge in a region of interest (ROI). Biological experiments demonstrate the merits of the proposed approach.

  4. Initial performance evaluation of an indirect-detection, active matrix flat-panel imager (AMFPI) prototype for megavoltage imaging

    International Nuclear Information System (INIS)

    Purpose: The development of the first prototype active matrix flat-panel imager (AMFPI) capable of radiographic and fluoroscopic megavoltage operation is reported. The signal and noise performance of individual pixels is empirically quantified. Results of an observer-dependent study of imaging performance, using a contrast-detail phantom, are detailed and radiographic patient images are shown. Finally, a theoretical investigation of the zero-frequency detective quantum efficiency (DQE) performance of such imagers, using a cascaded systems formalism, is presented. Methods and Materials: The imager is based on a 508-μm pitch, 26 x 26 cm2 array which detects radiation indirectly via an overlying copper plate + phosphor screen converter. Results: Due to its excellent optical coupling, the imager exhibits sensitivity superior to that of video-based systems. With an ∼133 mg/cm2 Gd2O2S:Tb screen the system is x-ray quantum-noise-limited down to ∼0.3 cGy, conservatively, and extensions of this behavior to even lower doses by means of reduced additive electronic noise is predicted. The observer-dependent study indicates performance superior to that of conventional radiotherapy film while the patient images demonstrate good image quality at 1 to 4 MU. The theoretical studies suggest that, with a 133 mg/cm2 Gd2O2S:Tb screen, the system would provide DQE performance equivalent to that of video-based systems and that almost a factor of two improvement in DQE is achievable through the incorporation of a 400 mg/cm2 screen. Conclusion: The reported prototype imager is the first megavoltage AMFPI having performance characteristics consistent with practical clinical operation. The superior contrast-detail sensitivity of the imager allows the capture of high-quality 6- and 15-MV images at minimal dose. Moreover, significant performance improvements, including extension of the operational range up to full portal doses, appear feasible. Such capabilities could be of considerable

  5. Missed diagnosis analysis of occult lung cancer by X-ray and the clinical significance of CT scans%隐匿型肺癌X线胸片漏诊分析及CT扫描的临床意义

    Institute of Scientific and Technical Information of China (English)

    温栋梁

    2014-01-01

    目的:分析 X 线胸片漏诊隐匿性肺癌的原因,并评价 CT 扫描对隐匿性肺癌的诊断价值。方法选择 X 线漏诊的隐匿性肺癌43例患者为研究对象。通过比较 X 线和 CT 检查结果,分析 X 线漏诊原因。结果43例患者正位 X 线胸片结果显示无异常,行侧位 X 线胸片检查后,30例患者依然未见异常。CT 扫描证实43例患者全为隐匿性肺癌。CT 扫描对支气管腔内、肺门区肿块及纵隔淋巴结肿大的显示情况优于 X 线胸片检查,差异有统计学意义(P ﹤0.05)。结论 X 线诊断隐匿性肺癌的漏诊率高。对于疑似隐匿性肺癌的患者,有必要行 CT 扫描,及早发现隐匿性肺癌,进一步确定病情,并采取针对性治疗。%Objective To analyze the missed diagnosis causes of occult lung cancer by X-ray, and evaluate the diagnosis value of CT scans on occult lung cancer. Methods Forty-three patients with occult lung cancer missed diagnosed by X-ray were chose as study objects. By comparing the results of X-ray and CT examination,the missed diagnosis causes of occult lung cancer by X-ray were analyzed. Re-sults The anteroposterior chest X-ray results were not abnormal in all of the 43 patients,and the lateral chest X-ray results were not abnormal in 30 patients. All of the 43 patients were confirmed with occult lung cancer by CT scans. CT scan was superior to the chest X-ray in display the bronchial lumen,lung hilar tumor and mediastinal lymph nodes enlargement,there were significant differences( P ﹤ 0. 05). Conclusions The missed diagnosis rate of occult lung cancer by X-ray is high. For patients with suspec-ted occult lung cancer,CT scan is necessary to early detection of occult lung cancer,further define the disease,and take targeted treatment.

  6. Microfocussing of synchrotron X-rays using X-ray refractive lens developed at Indus-2 deep X-ray lithography beamline

    Indian Academy of Sciences (India)

    V P Dhamgaye; M K Tiwari; K J S Sawhney; G S Lodha

    2014-07-01

    X-ray lenses are fabricated in polymethyl methacrylate using deep X-ray lithography beamline of Indus-2. The focussing performance of these lenses is evaluated using Indus-2 and Diamond Light Source Ltd. The process steps for the fabrication of X-ray lenses and microfocussing at 10 keV at moderate and low emittance sources are compared.

  7. Simulation of grating-based X-ray phase contrast tomography

    International Nuclear Information System (INIS)

    Grating-based X-ray phase contrast tomography proved to achieve better contrast in soft tissue than conventional X-ray absorption. The real part of the refractive index of the tissue results in a slight deflection of the X-rays. These tiny angles of approximately 20 nrad can be detected by a combination of a phase and absorption gratings. With an absorption grating near the anode of a conventional X-ray tube the method is applicable as part of a medical device. Hence X-ray phase contrast can be used in the detection of soft tissue pathologies e.g. breast tumor in mammography. The application in the clinics demands the lowest dose for the patient though the best contrast to noise ratio (CNR). To accomplish this, we simulated the imaging varying the height and pitch of the gratings for a given power and spectrum of the X-ray tube. Source, detector and grating distances were under the constraint of the dimensions of a putative computer tomograph. Optimal combinations where found for maximal CNR. The results will be important for the design and implementation of the X-ray phase contrast method in commercial CT devices.

  8. Simulation of grating-based X-ray phase contrast tomography

    Energy Technology Data Exchange (ETDEWEB)

    Achterhold, Klaus; Herzen, Julia; Pfeiffer, Franz [Department of Physics (E17) and Institute of Medical Engineering (IMETUM), Technische Universitaet Muenchen (Germany)

    2011-07-01

    Grating-based X-ray phase contrast tomography proved to achieve better contrast in soft tissue than conventional X-ray absorption. The real part of the refractive index of the tissue results in a slight deflection of the X-rays. These tiny angles of approximately 20 nrad can be detected by a combination of a phase and absorption gratings. With an absorption grating near the anode of a conventional X-ray tube the method is applicable as part of a medical device. Hence X-ray phase contrast can be used in the detection of soft tissue pathologies e.g. breast tumor in mammography. The application in the clinics demands the lowest dose for the patient though the best contrast to noise ratio (CNR). To accomplish this, we simulated the imaging varying the height and pitch of the gratings for a given power and spectrum of the X-ray tube. Source, detector and grating distances were under the constraint of the dimensions of a putative computer tomograph. Optimal combinations where found for maximal CNR. The results will be important for the design and implementation of the X-ray phase contrast method in commercial CT devices.

  9. Observing Solvation Dynamics with Simultaneous Femtosecond X-ray Emission Spectroscopy and X-ray Scattering

    DEFF Research Database (Denmark)

    Haldrup, Kristoffer; Gawelda, Wojciech; Abela, Rafael;

    2016-01-01

    rearrangement of the solute with X-ray emission spectroscopy, thus establishing time zero for the ensuing X-ray diffuse scattering analysis. The simultaneously recorded X-ray diffuse scattering atterns reveal slower subpicosecond dynamics triggered by the intramolecular structural dynamics of the photoexcited......, confirming previous ab initio molecular dynamics simulations. Structural changes in the aqueous solvent associated with density and temperature changes occur with similar to 1 ps time constants, characteristic for structural dynamics in water. This slower time scale of the solvent response allows us...

  10. The Swift X-ray Telescope Cluster Survey II. X-ray spectral analysis

    OpenAIRE

    P. TozziINAF, Osservatorio Astrofisico di Firenze; A. Moretti(Fermilab, Batavia, IL, USA); Tundo, E.; Liu, T.; Rosati, P.; Borgani, S.; Tagliaferri, G.; S. Campana; Fugazza, D.; Avanzo, P. D.

    2014-01-01

    (Abridged) We present a spectral analysis of a new, flux-limited sample of 72 X-ray selected clusters of galaxies identified with the X-ray Telescope (XRT) on board the Swift satellite down to a flux limit of ~10-14 erg/s/cm2 (SWXCS, Tundo et al. 2012). We carry out a detailed X-ray spectral analysis with the twofold aim of measuring redshifts and characterizing the properties of the Intra-Cluster Medium (ICM). Optical counterparts and spectroscopic or photometric redshifts ...

  11. X-ray variability in a complete sample of Soft X-ray selected AGN

    OpenAIRE

    D. Grupe; Thomas, H. -C.; Beuermann, K.

    2000-01-01

    We present ROSAT All-Sky Survey and ROSAT pointed observations (PSPC and HRI) of a complete sample of 113 bright soft X-ray AGN selected from the ROSAT Bright Source Catalog. We compare these observations in order to search for extreme cases of flux and spectral X-ray variability - X-ray transient AGN. Three definite transients and one transient candidate are found. The other sources show amplitude variations typically by factors of 2-3 on timescales of years. We found that the variability st...

  12. A Soft X-ray Polarimeter Designed for Broad-band X-ray Telescopes

    OpenAIRE

    Marshall, Herman L.

    2007-01-01

    A novel approach for measuring linear X-ray polarization over a broad-band using conventional imaging optics and cameras is described. A new type of high efficiency grating, called the critical angle transmission grating is used to disperse soft X-rays radially from the telescope axis. A set of multilayer-coated paraboloids re-image the dispersed X-rays to rings in the focal plane. The intensity variation around these rings is measured to determine three Stokes parameters: I, Q, and U. By lat...

  13. Femtosecond X-ray Absorption Spectroscopy at a Hard X-ray Free Electron Laser

    DEFF Research Database (Denmark)

    Lemke, Henrik T.; Bressler, Christian; Chen, Lin X.;

    2013-01-01

    X-ray free electron lasers (XFELs) deliver short (time-resolved studies. Here we show that, despite the inherent instabilities of current (SASE based) XFELs, they can be used for measuring high......-quality X-ray absorption data and we report femtosecond time-resolved X-ray absorption near-edge spectroscopy (XANES) measurements of a spin-crossover system, iron(II) tris(2,2'-bipyridine) in water. The data indicate that the low-spin to high-spin transition can be modeled by single-exponential kinetics...

  14. Flattening filter removal for improved image quality of megavoltage fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, James D.; Kirichenko, Alexander; Gayou, Olivier [Department of Radiation Oncology, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212 (United States)

    2013-08-15

    Purpose: Removal of the linear accelerator (linac) flattening filter enables a high rate of dose deposition with reduced treatment time. When used for megavoltage imaging, an unflat beam has reduced primary beam scatter resulting in sharper images. In fluoroscopic imaging mode, the unflat beam has higher photon count per image frame yielding higher contrast-to-noise ratio. The authors’ goal was to quantify the effects of an unflat beam on the image quality of megavoltage portal and fluoroscopic images.Methods: 6 MV projection images were acquired in fluoroscopic and portal modes using an electronic flat-panel imager. The effects of the flattening filter on the relative modulation transfer function (MTF) and contrast-to-noise ratio were quantified using the QC3 phantom. The impact of FF removal on the contrast-to-noise ratio of gold fiducial markers also was studied under various scatter conditions.Results: The unflat beam had improved contrast resolution, up to 40% increase in MTF contrast at the highest frequency measured (0.75 line pairs/mm). The contrast-to-noise ratio was increased as expected from the increased photon flux. The visualization of fiducial markers was markedly better using the unflat beam under all scatter conditions, enabling visualization of thin gold fiducial markers, the thinnest of which was not visible using the unflat beam.Conclusions: The removal of the flattening filter from a clinical linac leads to quantifiable improvements in the image quality of megavoltage projection images. These gains enable observers to more easily visualize thin fiducial markers and track their motion on fluoroscopic images.

  15. Evaluation of digital x-ray detectors for medical imaging applications

    OpenAIRE

    Konstantinidis, A.

    2011-01-01

    Digital x-ray detectors are now the detector of choice in many X-ray examinations. They have been accepted into clinical practice over the past decade but there are still ongoing developments in the technology. Complementary metal oxide semiconductor (CMOS) active pixel sensors (APS) are a novel digital technology that offers advantages compared to some of the more established approaches (charge-coupled devices (CCD), thin film transistor arrays (TFT) and CMOS passive pixel sensors (PPS)). Th...

  16. X-ray exposure hazards for physicians performing ablation procedures and device implantation

    DEFF Research Database (Denmark)

    Marinskis, Germanas; Bongiorni, Maria Grazia; Dagres, Nikolaos;

    2013-01-01

    The purpose of the survey was to evaluate physician's and authorities policies and clinical practices when using occupational X-ray during ablation procedures and device implantation. This survey shows infrequent use of lead gloves, radiation absorbing pads, and lead glass cabins, but increasing ...... use of three-dimensional mapping systems to decrease X-ray radiation hazards. Digital fluoroscopy with decreased frame rate is not used by approximately one-third of responding centres....

  17. Neutron and X-ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Carini, Gabriella [SLAC National Accelerator Lab., Menlo Park, CA (United States); Denes, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gruener, Sol [Cornell Univ., Ithaca, NY (United States); Lessner, Elianne [Dept. of Energy (DOE), Washington DC (United States). Office of Science Office of Basic Energy Sciences

    2012-08-01

    The Basic Energy Sciences (BES) X-ray and neutron user facilities attract more than 12,000 researchers each year to perform cutting-edge science at these state-of-the-art sources. While impressive breakthroughs in X-ray and neutron sources give us the powerful illumination needed to peer into the nano- to mesoscale world, a stumbling block continues to be the distinct lag in detector development, which is slowing progress toward data collection and analysis. Urgently needed detector improvements would reveal chemical composition and bonding in 3-D and in real time, allow researchers to watch “movies” of essential life processes as they happen, and make much more efficient use of every X-ray and neutron produced by the source The immense scientific potential that will come from better detectors has triggered worldwide activity in this area. Europe in particular has made impressive strides, outpacing the United States on several fronts. Maintaining a vital U.S. leadership in this key research endeavor will require targeted investments in detector R&D and infrastructure. To clarify the gap between detector development and source advances, and to identify opportunities to maximize the scientific impact of BES user facilities, a workshop on Neutron and X-ray Detectors was held August 1-3, 2012, in Gaithersburg, Maryland. Participants from universities, national laboratories, and commercial organizations from the United States and around the globe participated in plenary sessions, breakout groups, and joint open-discussion summary sessions. Sources have become immensely more powerful and are now brighter (more particles focused onto the sample per second) and more precise (higher spatial, spectral, and temporal resolution). To fully utilize these source advances, detectors must become faster, more efficient, and more discriminating. In supporting the mission of today’s cutting-edge neutron and X-ray sources, the workshop identified six detector research challenges

  18. Some observational aspects of compact galactic X-ray sources

    International Nuclear Information System (INIS)

    This thesis contains the following observations of compact galactic X-ray sources: i) the X-ray experiments onboard the Astronomical Netherlands Satellite ANS, ii) a rocket-borne ultra soft X-ray experiment and iii) the Objective Grating Spectrometer onboard the EINSTEIN observatory. In Chapter I the various types of compact galactic X-ray sources are reviewed and put into the perspective of earlier and following observations. In Chapter II the author presents some of the observations of high luminosity X-ray sources, made with ANS, including the detection of soft X-rays from the compact X-ray binary Hercules X-1 and the ''return to the high state'' of the black hole candidate Cygnus X-1. Chapter III deals with transient X-ray phenomena. Results on low luminosity galactic X-ray sources are collected in Chapter IV. (Auth.)

  19. Exploration of computerized image processing in underexposed and overexposed X-rays of bones and joints

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhao-chen; ZHANG You-jun; FENG Cheng-qiang; ZHU Yuan-zhong; YAN Shi-yi; LIU Yu-jin

    2004-01-01

    Objective: To study the effective computerized image processing of underexposed and overexposed X-rays of bones and joints. Methods: Ninety-nine conventional X-ray images (82 were overexposed and 17 were underexposed),scanned by an UMAX Astra 4000U Scanner, were converted into digital images on the basis of their analog images. A computerized imaging processing program consisting of five functional modules such as Contrast Stretch, Fast Flourier Transform (FFT), Image Smoothing Modules, Inverse Fast Flourier Transform (IFFT) and Nonlinear Transform performed image contrast stretch and smoothing. Three senior doctors from hospital image sections made their evaluation of all the processed images. Results: Of 82 overexposed films, 71 met the clinical requirements after image processing, and 11 were unable to be applied to clinical diagnosis, accounting for 87% and 13% respectively. Of the other 17 underexposed X-ray images, 11 met the clinical requirements while 6 were not, making a percentage of 64 and 35. Conclusion: Image contrast stretch and smoothing processing are significantly effective on conventional X-ray images which were inappropriately exposed, and can avoid more X-ray radiation caused by handling of radiological photograph again. This method can decrease hospital cost and provide acute and effective X-ray examinations for the treatment and cure for critical patients.

  20. Calculation of x-ray scattering patterns from nanocrystals at high x-ray intensity.

    Science.gov (United States)

    Abdullah, Malik Muhammad; Jurek, Zoltan; Son, Sang-Kil; Santra, Robin

    2016-09-01

    We present a generalized method to describe the x-ray scattering intensity of the Bragg spots in a diffraction pattern from nanocrystals exposed to intense x-ray pulses. Our method involves the subdivision of a crystal into smaller units. In order to calculate the dynamics within every unit, we employ a Monte-Carlo-molecular dynamics-ab-initio hybrid framework using real space periodic boundary conditions. By combining all the units, we simulate the diffraction pattern of a crystal larger than the transverse x-ray beam profile, a situation commonly encountered in femtosecond nanocrystallography experiments with focused x-ray free-electron laser radiation. Radiation damage is not spatially uniform and depends on the fluence associated with each specific region inside the crystal. To investigate the effects of uniform and non-uniform fluence distribution, we have used two different spatial beam profiles, Gaussian and flattop. PMID:27478859