WorldWideScience

Sample records for digital x-ray equipment

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

    International Nuclear Information System (INIS)

    Zelikman, Mikhail; Kruchinin, Sergey

    2013-06-01

    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

  2. Time estimate (topening + tclosing) of shutter of an X-ray equipment using a digital chronometer

    International Nuclear Information System (INIS)

    Quaresma, D.S.; Oliveira, P.H.T.M.; Gallo, V.F.M.; Jordao, B.O.; Carvalho, R.J.; Cardoso, R.S.; Peixoto, J.G.P.

    2014-01-01

    In this work the measurement of time t opening + t closing opening and closing the shutter of Pantak HF160 X-ray equipment was performed. It is understood by the shutter device responsible for allowing or not the flow of X-rays that are produced by the X-ray tube through the orifice of a shield. To estimate the running time for a digital chronometer calibrated in the Time Service Division (DSHO) National Observatory (ON) was used. (author)

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  4. X-ray equipment

    International Nuclear Information System (INIS)

    Redmayne, I.G.B.

    1988-01-01

    The patent concerns a warning and protection system for mobile x-ray equipment used for 'on site' radiography, so that workers in the vicinity of such a working unit can be alerted to its presence. The invention is a local repeater warning system which gives a preliminary warning that energisation of the tubehead is imminent, as well as a switch near the tubehead to abort or inhibit energisation. The latter switch allows personnel caught in the vicinity of the tubehead to prevent energisation. The preliminary warning may be flashing lamps or by a klaxon. The control unit for the equipment may include a monitoring circuit to detect failure of the warning light or klaxon. (U.K.)

  5. X-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Redmayne, I.G.B.

    1988-01-06

    The patent concerns a warning and protection system for mobile x-ray equipment used for 'on site' radiography, so that workers in the vicinity of such a working unit can be alerted to its presence. The invention is a local repeater warning system which gives a preliminary warning that energisation of the tubehead is imminent, as well as a switch near the tubehead to abort or inhibit energisation. The latter switch allows personnel caught in the vicinity of the tubehead to prevent energisation. The preliminary warning may be flashing lamps or by a klaxon. The control unit for the equipment may include a monitoring circuit to detect failure of the warning light or klaxon. (U.K.).

  6. Evaluation of body simulator for chest and abdomen in digital X-ray equipment

    International Nuclear Information System (INIS)

    Soares, Sidney S.; Cardoso, Gabriela P.; Oliveira, Giovanni Antônio P.; Batista, Adriana S.M.; Pereira, Esther Lorrayne M.

    2017-01-01

    The use of body simulators to control the quality of X-ray images is a practice that guarantees the control of essential parameters for diagnosis by the technique. The evolution of the equipment, between the analogue, digital computerized radiology (CR) and direct radiography (DR), requires evaluation of the equivalence in grayscale, of simulators, for an adjustment according to the specific technology of obtaining the image. In this sense, the present work presents the evaluation of a body simulator with regard to the representation of mean values of signal, noise and contrast obtained in chest radiographs and panoramic of the abdomen. For the thorax the cardiac region was considered as simulation target and for the abdomen simulation of the liver and small intestine. We used a retrospective study of images obtained with X-ray equipment - CR system, in which the images were studied using the ImageJ program, generating a data catalog. These were subsequently compared with those obtained experimentally using gel filled polymer body simulator. For the validation of the simulator, it was observed the gel equivalence of filling of the polymer box required to reach the image parameters of the cataloged radiographs. The results are discussed as to the physical principles of radiation interaction with biological and equivalent tissues

  7. Film replacement by digital x-ray detectors - the correct procedure and equipment

    International Nuclear Information System (INIS)

    Ewert, U.; Zscherpel, U.; Bavendiek, K.

    2004-01-01

    New digital detectors were developed for medical applications, which have the potential to substitute the X-ray film and revolutionise the radiological technique. Digital Detector Arrays (DDA: Flat Panel Detectors, Line Detectors) and Imaging Plates (Computed Radiography) allow a fast detection of radiographic images in a shorter time and with higher dynamic than film applications. Companies report about a reduction of exposure time down to 5 - 25% in comparison to NDT film exposures. This provides together with the reduction of consumables economical (and also ecological) benefits and short amortisation periods. But this does not always provide the same image quality as NDT film. The requirements of the European and USA standards for film radiography are analysed to derive correct requirements for the digital image quality and procedures for prediction and measurement of image quality. Basically the USA standards seem to be more tolerant for these new innovative technologies. New standard proposals use signal/noise ratio and unsharpness as dominant parameters for image quality. Specialised measurement procedures are described. The properties of the new detectors can be controlled by electronics and exposure conditions. New names appear in literature like 'direct radiography' and 'film replacement techniques'. The basic advantage of the new digital techniques is the possibility to use numeric procedures for image interpretation. Industrial radiology can be optimised for crack detection as well as for analysis of flaw depth and shape measurement. Automated flaw detection, measurement of part dimensions and detection of completeness are used for serial part inspection devices. Parallel to the development of DDA's, an extraordinary increase of Computed Tomography (CT) applications can be observed. (author)

  8. Requirements for industrial x-ray equipment

    International Nuclear Information System (INIS)

    1987-01-01

    This safety code is concerned with the protection of all individuals who may be exposed to radiation emitted by X-ray equipment operating at energies up to 1 MeV as used in industrial radiography. This code presents basic radiation safety information for the protection of personnel operating and servicing X-ray equipment and other workers and the general public in the vicinity of areas where X-ray equipment is in operation. It specifies general safety features of design, construction and functioning of X-ray equipment and facilities; describes the responsibilities of the user, operator and maintenance personnel; contains recommendations to ensure that the X-ray equipment is used and maintained in accordance with the ALARA principle; and describes a program of personnel monitoring and radiation safety surveys. ( 6 refs., 5 tabs., 4 figs.)

  9. Traps in quality assurance of diagnostic X-ray equipment

    International Nuclear Information System (INIS)

    Meier, N.; Lenzen, H.; Fiebich, M.

    1992-01-01

    With the introduction of the German industrial protocol for quality assurance of X-ray equipment, everybody using X-ray machines fell into sort of trap or found some of the procedures misleading. Vigorous discussions were held on every conceivable aspect of this and other protocols, and are still in progress. This paper points out some of the common traps and considers a new type dosimeter, which allows a definite separation of quality assurance of X-ray equipment and of processing and which can also be used in future for quality assurance of digital radiography equipment. (orig.) [de

  10. Equipment, components and production of x-ray

    International Nuclear Information System (INIS)

    Idris Besar

    2004-01-01

    The contents of this chapter are follows - Equipment, Components and Production of x-Ray: x-ray system, generator, control panel. x-ray tube, cathode, anode, envelope, housing, collimator, other components, x-ray production, Bremsstrahlung x-ray, characteristic x-ray, heat production

  11. Chief objectives of the development of X-ray equipment engineering in Russia

    International Nuclear Information System (INIS)

    Blinov, N.N.; Varshavskij, Yu.V.; Zelikman, M.I.

    1997-01-01

    Based on the world tendencies in the development of X-ray diagnostic instruments the main problems int he development of domestic X-ray diagnostic equipment engineering are analyzed. Variant of basic equipment for modern X-ray room for digital biomedical radiography is proposed. Tendencies int he instrumentation of X-ray diagnosis are the following ones: X-ray computerized tomograph creation, development of telecontrolled X-ray computerized. complexes for biomedical X-ray complexes for digital biomedical radiography, automation of the film development

  12. Simulation in X-ray equipment manufacture

    International Nuclear Information System (INIS)

    Zhutyaev, S.G.; Martynov, E.E.; Mishkinis, B.Ya.; Chikirdin, Eh.G.

    1993-01-01

    Digital models for the overload and overheat protection of X-ray diagnostic are considered. The above models permit to account more correctly the tube performance peculiarities, to obtain the maximum efficiency and to prolong the service life. The models can be used in other feeding devices as well

  13. Defects in medical X-ray equipment

    International Nuclear Information System (INIS)

    Eder, H.; Wahl, H.; Troeger, W.

    1979-01-01

    A careful estimate of the effects on the genetically significant radiation load shows that it is in the same order of magnitude as the increase in the skin dose area product. This is to say that of the genetically significant radiation dose of about 500 mJ/kg (50 mrem) per year and person due to medical X-ray diagnostics, about 75 mJ/kg (7.5 mrem) are due to serious defects in X-ray equipment. (orig.) [de

  14. Patients Radiation Load Caused by Digitalised X-Ray Equipment

    International Nuclear Information System (INIS)

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

    2001-01-01

    Full text: The radiation load of population all over the world from medical examinations clearly demonstrate the importance of implementation of quality assurance and quality control programmes into the activities of radiological departments. The basic aim of quality assurance programme is to ensure that the radiation dose is kept as low as reasonably practicable consistent with adequate image quality. As many other fields, the rapid development of techniques brought change-over from the conventional analogue technique to the digital technique. In this connection conventional X-ray film is being abandoned and images are being viewed on either laser film or monitor. The main advantages of using digital equipment lay in improved image quality and diagnostic accuracy through digital image processing, reduction in patient exposure, cost reduction by reduction film usage, more efficient storage and retrieval of radiographic images through picture archiving. Several studies that have been conducted for comparison of various diagnostic examinations performed on digital and analogue X-ray equipment have shown that in barium meal examinations, there is potential for dose saving in the digital image intensifier technique. The aim of this study was to compare measured values of dose-area product for colon investigations using different X-ray equipment types, on digital and one analogue. Our material consisted of 60 randomly selected patients, 24 of them were examined with digital equipment and 36 patients with the analogue equipment. (author)

  15. Diagnostic x-ray equipment and its use

    International Nuclear Information System (INIS)

    1993-01-01

    The guide contains the requirements for the use, structure and operation of diagnostic x-ray equipment necessary to ensure the radiation safety of workers and patients. The guide is intended for the party responsible for operating the x-ray units, the staff operating, installing and maintaining x-ray examination equipment, and companies manufacturing and selling such equipment. Special requirements for mammographic and dental x-ray equipments are given in separate ST guides. (5 refs., 1 figs., 2 tabs.)

  16. 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...

  17. Digital X-ray imager

    International Nuclear Information System (INIS)

    1998-01-01

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

  18. Electronic quality control on dental x-rays equipment

    International Nuclear Information System (INIS)

    Pomares C, Martin

    1996-09-01

    A brief description of dental x-ray equipment is done. The non-invasive quality control is treated as than the responsibilities from the dentists to the patient and the equipment. A propose for quality control for dental x-ray equipment, film and developer is include

  19. Repeated pulsed x-ray emission equipment

    International Nuclear Information System (INIS)

    Terauchi, Hikaru; Iida, Satoshi

    1982-01-01

    X-ray diffraction technique has been applied to determine the spatial positions of atoms which compose a material, and it is needless to say that the technique is a fundamental means regardless of the fields of research. However, the application of X-ray diffraction to the research on physical properties has been so far limited to know the spatial positions of atoms or molecules under thermal equilibrium condition. The addition of time element to the conventional technique, that is, the analysis of material structure including the time-varying processes under non-equilibrium conditions, is considered to approach the elucidation of the essence of materials. The authors call this dynamic structural analysis. The authors have planned to analyze X-ray diffraction intensity which has the resolution of about 10 -8 s in the real time which is conjugate with energy. However, present pulsed X-ray sources are not suitable for diffraction experiment because the pulse width is too long or X-ray wavelength is too short. Accordingly, the authors have made for trial a pulsed X-ray source for diffraction experiment. Its specifications are: diode voltage (X-ray tube voltage) from 200 to 300 kV, diode current from 2 to 5 kA, pulse width of about 30ns, maximum repetition frequency 10 pps, and X-ray focus size of 2 mm diameter. One of the features of this source is the repeated generation of pulsed X-ray. This is the first trial in the world, and is indispensable to the dynamic structural analysis described above. The quality of the emitted X-ray is also written. (Wakatsuki, Y.)

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

    International Nuclear Information System (INIS)

    Asano, Hiroshi; Miyake, Hiroyuki; Yamamoto, Keiichi

    2000-01-01

    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

  1. X-ray radiography equipment for patients in standing position

    International Nuclear Information System (INIS)

    Snijder, J.G.N.

    1974-01-01

    X-ray radiography equipment suited for patients in standing position is described. The patient's body centre of mass is indicated by its vertical projection line appearing on the X-ray image. To that end, an X-ray absorbing wire is positioned through the centre of mass by means of an electrical signal acting on a servomotor and derived from the pressure on three non-colinear points in the foot plate through an analogue computer

  2. A compliance testing program for diagnostic X-ray equipment

    International Nuclear Information System (INIS)

    Hutchinson, D.E.; Cobb, B.J.; Jacob, C.S.

    1999-01-01

    Compliance testing is nominally that part of a quality assurance program dealing with those aspects of X-ray equipment performance that are subject to radiation control legislation. Quality assurance programs for medical X-ray equipment should be an integral part of the quality culture in health care. However while major hospitals and individual medical centers may implement such programs with some diligence, much X-ray equipment can remain unappraised unless there is a comprehensive regulatory inspection program or some form of compulsion on the equipment owner to implement a testing program. Since the late 1950s all X-ray equipment in the State of Western Australia has been inspected by authorized officers acting on behalf of the Radiological Council, the regulatory authority responsible for administration of the State's Radiation Safety Act. However, economic constraints, coupled with increasing X-ray equipment numbers and a geographically large State have significantly affected the inspection rate. Data available from inspections demonstrate that regular compliance and performance checks are essential in order to ensure proper performance and to minimize unnecessary patient and operator dose. To ensure that diagnostic X-ray equipment complies with accepted standards and performance criteria, the regulatory authority introduced a compulsory compliance testing program for all medical, dental and chiropractic diagnostic X-ray equipment effective from 1 January 1997

  3. Digital X-ray Imaging in Dentistry

    International Nuclear Information System (INIS)

    Kim, Eun Kyung

    1999-01-01

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

  4. 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.

  5. X-ray digital wavefront sensor development

    International Nuclear Information System (INIS)

    Idir, Mourad; Fricker, Sebastien; Modi, Mohammed H.; Potier, Jonathan

    2010-01-01

    Phase contrast imaging (PCI) is a wavefront sensing method that uses a series of intensity images to reconstruct the wavefront. The lateral resolution of PCI is limited mainly by the resolution of the intensity images. PCI provides a simple and efficient technique for characterizing X-ray mirrors. A simulation experiment was conducted to demonstrate the performances of PCI. The results of these experiments have shown the feasibility and potential performances of this method. The use of phase retrieval presents opportunities for greatly simplifying the techniques and apparatus used for characterizing optical surfaces and systems, particularly aspherical surfaces. This paper addresses the design, implementation and performances of an integrated at wavelength digital wavefront sensor.

  6. The MCNP simulation of the X-ray leakage of X-ray security inspection equipment

    International Nuclear Information System (INIS)

    Wang Kai; Liu Bin; Hu Wenchao; Zhao Wei

    2011-01-01

    Objective: To simulate the radiation leakage of the X-ray security inspection equipment used in the subways stations. Methods: We use the MCNP4C code to simulate the X-ray leakage of the equipment during the working process. Result: the biggest amount of radiation received by the body is 8.26 μSv/a, however, if the Lead screens of the X-ray security equipment is intact, the amount of radiation received by the body is only 0.0727 μSv/a. The final. Conclusions: When the baggage get in /out the X-ray security inspection equipment, the gas in Lead screens was made, and then the amount of radiation received by human body increased; The amount of radiation received by the body is close to but still below 10 μSv/a which is the exemption criteria set by the 'safety of radiation sources of ionizing radiation protection and basic standards'(GB18871-2002). (authors)

  7. Usability improvement of x-ray food inspection equipment

    International Nuclear Information System (INIS)

    Ohira, Norihiro; Yamaguchi, Takashi; Ohara, Mamoru; Shimizu, Hideaki; Kamimura, Kunio; Saiki, Hideo

    2010-01-01

    To properly set up X-ray inspection equipment of foreign bodies in foods properly has become more and more complicated and time-consuming, because digital image processing used in it has more parameters for more precise inspecting. In this paper, it is reported some methods to lighten the work load of workers who set up the parameters. Using Statistical methods, we construct an auto setting lookup table for adjusting contrast and parameters of inspection algorithm. With the former we confirmed an expansion of a range of grey levels that include domain of foreign bodies in sample data. Furthermore, with we constructed in our former research, we can set automatically limit of parameters that judge input product's image to be not including foreign bodies. It is suitable for food inspection system, since users prefer severely inspecting of foreign products. (author)

  8. Image formation in diagnostic X-ray equipment

    International Nuclear Information System (INIS)

    Boer, J.A. den.

    1983-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  10. Fundamentals for cost calculations of X-ray equipment

    International Nuclear Information System (INIS)

    Bossard, F.

    1985-01-01

    Economic implications of running an X-ray departement in Switzerland will be illustrated by comparing operating costs of private radiological institutes with and without CT to the operating costs of large radiological departments in hospitals with and without CT and to the operating costs of simple X-ray equipment in general practicioners' offices. - These costs calculations form the basis for cost-benefit analyses. (orig.) [de

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

    International Nuclear Information System (INIS)

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

    1986-08-01

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

  12. The IHS diagnostic X-ray equipment radiation protection program

    International Nuclear Information System (INIS)

    Knapp, A.; Byrns, G.; Suleiman, O.

    1994-01-01

    The Indian Health Service (IHS) operates or contracts with Tribal groups to operate 50 hospitals and approximately 165 primary ambulatory care centers. These facilities contain approximately 275 medical and 800 dental diagnostic x-ray machines. IHS environmental health personnel in collaboration with the Food and Drug Administration's (FDA) Center for Devices and Radiological Health (CDRH) developed a diagnostic x-ray protection program including standard survey procedures and menu-driven calculations software. Important features of the program include the evaluation of equipment performance collection of average patient entrance skin exposure (ESE) measurements for selected procedures, and quality assurance. The ESE data, collected using the National Evaluation of X-ray Trends (NEXT) protocol, will be presented. The IHS Diagnostic X-ray Radiation Protection Program is dynamic and is adapting to changes in technology and workload

  13. Radiographic techniques adaptation for any conventional X-ray equipment

    International Nuclear Information System (INIS)

    Pina, Diana R.; Ghilardi Netto, Thomaz; Martinez, Alexandre S.; Duarte, Sergio B.; Trad, Clovis S.; Brochi, Marco Aurelio C.

    2001-01-01

    In order to obtain a better risk-benefice relation in diagnostic radiology it turns out to be essential the control and optimization of the radiographic techniques used to reduce the absorbed doses until its minimum, keeping or adjusting the diagnostic image at any X-ray equipment. The present work deals with the standardization of radiographic techniques of chest, skull and pelvis, which is more suitable for obtaining a safe diagnostic with smaller doses, for a standard patient, at any conventional X-ray equipment. (author)

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

    African Journals Online (AJOL)

    2011-03-02

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

  15. Field size and centring for conventional X-ray equipment

    International Nuclear Information System (INIS)

    Klimpel, H.; Kreienfeld, H.; Overbeck, R.

    1989-01-01

    Since 1973, all X-ray equipment for medical applications in the Federal Republic of Germany has had to be examined according to the requirements of the German ''Rontgenverordnung'' before it is used on patients and after each essential modification of design or construction. These examinations are carried out by inspectors appointed by the authorities, e.g. TUV. The field size adjustment and the centring of the radiation beam in relation to the image reception area is checked, along with other tests. To increase quality assurance in X-ray diagnosis, since the mid-1980s X-ray equipment has also been subject to in-service inspections to an increasing extent. (author)

  16. The radioprotection inspection manual for odontologic X-rays equipment

    International Nuclear Information System (INIS)

    Almeida, C.D. de.

    1988-01-01

    The inspection manual for odontologic X-ray, using films and thermoluminescent dosemeters are showed, decreasing the time of exposition by some recommendation. Some calculations are also cited, for decrease the exposure time, for filtrating the equipment and for a radiometric survey. (C.G.C.) [pt

  17. Diagnostic X-ray equipment evaluation in Brazil

    International Nuclear Information System (INIS)

    Campos de Araujo, A.M.; Peixoto, J.E.; Reis, V.R.G.

    1980-01-01

    A survey of the diagnostic X-ray equipment in use in Brazil is presented. Procedures for testing radiation quality (kilovoltage and filtration), tube output, beam collimation and protection devices are described and results of tests are tabulated. (H.K.)

  18. Control system of digital x-ray systems by quality parameters

    International Nuclear Information System (INIS)

    Balashov, S.V.; Kovalenko, Yu.N.

    2013-01-01

    The paper proposed a control system of X-ray digital equipment on quality indicators. Two basic parameters were determined: image quality and patients' radiation load. A method for monitoring these indicators is proposed. The criterion of equipment suitability is to obtain control digital X-ray images of diagnostically acceptable quality at a fixed low entrance dose in the plane of the digital detector. It is shown that the control system of X-ray digital equipment based on indicators of quality is the most appropriate in situations of deficit of financial resources, since minimizing the costs for the purchase and running of control systems, does not require highly skilled technical personnel, and reduces the duration of the equipment inspection. (authors)

  19. X-ray images in the digital mode

    International Nuclear Information System (INIS)

    Buchmann, F.; Balter, S.

    1981-01-01

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

  20. Real-time digital x-ray subtraction imaging

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  1. Real-time digital X-ray subtraction imaging

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  2. Characteristics of specifications of transportable inverter-type X-ray equipment

    CERN Document Server

    Yamamoto, K; Asano, H

    2003-01-01

    Our X-ray systems study group measured and examined the characteristics of four transportable inverter-type X-ray equipments. X-ray tube voltage and X-ray tube current were measured with the X-ray tube voltage and the X-ray tube current measurement terminals provided with the equipment. X-ray tube voltage, irradiation time, and dose were measured with a non-invasive X-ray tube voltage-measuring device, and X-ray output was measured by fluorescence meter. The items investigated were the reproducibility and linearity of X-ray output, error of pre-set X-ray tube voltage and X-ray tube current, and X-ray tube voltage ripple percentage. The waveforms of X-ray tube voltage, the X-ray tube current, and fluorescence intensity draw were analyzed using the oscilloscope gram and a personal computer. All of the equipment had a preset error of X-ray tube voltage and X-ray tube current that met Japanese Industrial Standards (JIS) standards. The X-ray tube voltage ripple percentage of each equipment conformed to the tendenc...

  3. An engineering development of fluoroscopic X-ray medical equipment based-on fluorescent screen

    International Nuclear Information System (INIS)

    Ferry Suyatno; I Putu Susila; Djoko Sukmono

    2011-01-01

    Fluoroscopic x-ray medical equipment uses fluorescent screen to capture structural image of organs. Unlike conventional x-ray equipment which uses film, in the fluoroscopic x-ray, the resulting image is visualized on the fluorescent screen and directly observed by physicians in the patients' rooms. In this study, we developed an image capture system that transforms the image on the fluorescent screen into digital data, which is then transferred to computer for visualization and further processing. By using this system, the observation of the resulting image can be done on a computer that is placed in the control room. The image can also be stored easily and at low cost compared to conventional film. The experiment shows that the system could be used to capture image of the object. However, its quality needs to be improved. In the future, the system will be modified and tested with different types of cameras to obtain better results. (author)

  4. Accidental over-exposure from dental X-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, B G [National Radiological Protection Board, Harwell (UK)

    1976-07-01

    A description is given of an unusual dental X-ray procedure which resulted in accidental over-exposure both to the dentist and to several of his patients when a short-circuit was present in newly-installed equipment. The short-circuit by-passed the exposure control and energized the tube for certain orientations of the X-ray tube. The dentist left the patients, who wore protective aprons, to initiate the exposure themselves, using the control button. Although the warning lights were on, the dentist was not present in the room during the exposure, and the over-exposures were only detected when the developed X-ray films were found to be completely blackened. A reconstruction of the procedure enabled estimates to be made of the dose equivalents to the dentist's body and to the skin of the head, the eyes and the gonads of the patients. The dentist had overlooked several of basic principles recommended in the Code of Practice for the Protection of Persons against Ionizing Radiations from Medical and Dental Use (1972). It is pointed out that incidents involving failure of dental equipment (usually the timer mechanism) are not infrequent.

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  6. The digital flat-panel X-Ray detectors

    International Nuclear Information System (INIS)

    Risticj, S. Goran

    2013-01-01

    In a digital imaging system, the incident x-ray image must be sampled both in the spatial and intensity dimensions. In the spatial dimensions, samples are obtained as averages of the intensity over picture elements or pixels. In the intensity dimension, the signal is digitalized into one of a finite number of levels or bits. Two main types of digital flat-panel detectors are based on the direct conversion, which contains the photoconductor, and on indirect conversion, which contains phosphor. The basics of these detectors are given. Coupling traditional x-ray detection material such as photoconductors and phosphors with a large-area active-matrix readout structure forms the basis of flat panel x-ray images. Active matrix technology provides a new, highly efficient, real time method for electronically storing and measuring the product of the x-ray interaction stage whether the product is visible wavelength photons or electrical charges. The direct and indirect detectors, made as the active-matrix flat-panel detectors containing sensing/storage elements, switching elements (diodes or thin film transistors (TFTS)) and image processing module, are described. Strengths and limitations of stimulable phosphors are discussed. The main advantages and disadvantages of mentioned x-ray detectors are also analyzed. (Author)

  7. Characteristics of specifications of transportable inverter-type X-ray equipment

    International Nuclear Information System (INIS)

    Yamamoto, Keiichi; Miyazaki, Shigeru

    2003-01-01

    Our X-ray systems study group measured and examined the characteristics of four transportable inverter-type X-ray equipments. X-ray tube voltage and X-ray tube current were measured with the X-ray tube voltage and the X-ray tube current measurement terminals provided with the equipment. X-ray tube voltage, irradiation time, and dose were measured with a non-invasive X-ray tube voltage-measuring device, and X-ray output was measured by fluorescence meter. The items investigated were the reproducibility and linearity of X-ray output, error of pre-set X-ray tube voltage and X-ray tube current, and X-ray tube voltage ripple percentage. The waveforms of X-ray tube voltage, the X-ray tube current, and fluorescence intensity draw were analyzed using the oscilloscope gram and a personal computer. All of the equipment had a preset error of X-ray tube voltage and X-ray tube current that met Japanese Industrial Standards (JIS) standards. The X-ray tube voltage ripple percentage of each equipment conformed to the tendency to decrease when X-ray tube voltage increased. Although the X-ray output reproducibility of system A exceeded the JIS standard, the other systems were within the JIS standard. Equipment A required 40 ms for X-ray tube current to reach the target value, and there was some X-ray output loss because of a trough in X-ray tube current. Owing to the influence of the ripple in X-ray tube current, the strength of the fluorescence waveform rippled in equipments B and C. Waveform analysis could not be done by aliasing of the recording device in equipment D. The maximum X-ray tube current of transportable inverter-type X-ray equipment is as low as 10-20 mA, and the irradiation time of chest X-ray photography exceeds 0.1 sec. However, improvement of the radiophotographic technique is required for patients who cannot move their bodies or halt respiration. It is necessary to make the irradiation time of the equipments shorter for remote medical treatment. (author)

  8. X-ray imaging using digital cameras

    Science.gov (United States)

    Winch, Nicola M.; Edgar, Andrew

    2012-03-01

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

  9. Real-time digital x-ray subtraction imaging

    International Nuclear Information System (INIS)

    Mistretta, C.A.

    1982-01-01

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

  10. Valorization procedure of x-ray equipment in the mammography equipment

    International Nuclear Information System (INIS)

    Ruiz, M. A.; Ordonez, J.; Antolin, E.; Andres, J. C. de; Gonzalez, I.; Arranz, L.; Sastre, J. M.; Ferrer, N.

    2006-01-01

    The Ramon y Cajal Hospital mammography service has three X-rays units, two of them with high resolution computed radiography (CR) system and one with flat-panel (FP)-based full-field digital mammography system. Periodic control dose tests in patients have shown lower glandular dose levels (DGM) than references provided by European Protocol for de Quality Control of de Physical and Technical Aspects of Mammography Screening. In this work, we have tried to establish an easy method for DGM calculation which is representative of the three equipment results. For this aim, we have defined an index which is measured along the time like a reference point. This index is defined as the relation between the blind test punctuations of a standard phantom image given by at least three radiologists in the Unit, and the average DGM values obtained in 20 patients in each Unit (using random thickness and random mama composition). (Author)

  11. Portable X-ray diffractometer equipped with XRF for archaeometry

    Science.gov (United States)

    Uda, M.; Ishizaki, A.; Satoh, R.; Okada, K.; Nakajima, Y.; Yamashita, D.; Ohashi, K.; Sakuraba, Y.; Shimono, A.; Kojima, D.

    2005-09-01

    A portable X-ray diffractometer equipped with an X-ray fluorescence spectrometer was improved so as to get a diffraction pattern and a fluorescence spectrum simultaneously in air from one and the same small area on a specimen. Here, diffraction experiments were performed in two modes, i.e. an angle rotation mode and an energy dispersive mode. In the latter a diffraction pattern and a fluorescence spectrum were simultaneously recorded in a short time, 100 s or less, on one display. The diffractometer was tested in the field to confirm its performance. Targets chosen for this purpose were a bronze mirror from the Eastern Han Dynasty (25-220), and a stupa and its pedestal which are part of the painted statue of "Tamonten holding a stupa" from the Heian Period (794-1192), enshrined in the Engyouji temple founded in 996. The bronze mirror was identified as a product of the Han Dynasty from its chemical composition and the existence of the δ phase in the Cu-Sn alloy. The stupa and its pedestal were decorated with gold powder and gold leaf, respectively. From the XRF data of the pedestal, the underlying layer of gold leaf seems to have been painted with emerald green.

  12. Portable X-ray diffractometer equipped with XRF for archaeometry

    International Nuclear Information System (INIS)

    Uda, M.; Ishizaki, A.; Satoh, R.; Okada, K.; Nakajima, Y.; Yamashita, D.; Ohashi, K.; Sakuraba, Y.; Shimono, A.; Kojima, D.

    2005-01-01

    A portable X-ray diffractometer equipped with an X-ray fluorescence spectrometer was improved so as to get a diffraction pattern and a fluorescence spectrum simultaneously in air from one and the same small area on a specimen. Here, diffraction experiments were performed in two modes, i.e. an angle rotation mode and an energy dispersive mode. In the latter a diffraction pattern and a fluorescence spectrum were simultaneously recorded in a short time, 100 s or less, on one display. The diffractometer was tested in the field to confirm its performance. Targets chosen for this purpose were a bronze mirror from the Eastern Han Dynasty (25-220), and a stupa and its pedestal which are part of the painted statue of 'Tamonten holding a stupa' from the Heian Period (794-1192), enshrined in the Engyouji temple founded in 996. The bronze mirror was identified as a product of the Han Dynasty from its chemical composition and the existence of the δ phase in the Cu-Sn alloy. The stupa and its pedestal were decorated with gold powder and gold leaf, respectively. From the XRF data of the pedestal, the underlying layer of gold leaf seems to have been painted with emerald green

  13. X-ray examination equipment for heart diagnostics

    International Nuclear Information System (INIS)

    Kok, P.W.

    1979-01-01

    For heart catheterization the X-ray tube and the image intensifier can be shifted parallel to the scanning plane. Without moving the patient it is also possible to displace the system X-ray tube/image intensifier arbitrarily in space, while keeping up the direction of the X-ray beam. (RW) [de

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

    Science.gov (United States)

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

    2013-05-01

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

  15. Report based on fiscal 2000 diagnostic X-ray equipment questionnaire survey. Conditions of radiography

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Mitsuo [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Allied Health Sciences; Matsuura, Takatoshi [Sekishinkai Sayama Hospital, Saitama (Japan); Okuaki, Tomoyuki; Imai, Yoshio; Tsukamoto, Atsuko [Kanto Medical Center NTT EC, Tokyo (Japan); Ide, Toshinori [Kajima Corp., Tokyo (Japan). Kajima Clinic; Shinohara, Fuminori [Nippon Medical School, Kawasaki, Kanagawa (Japan). Second Hospital; Miyazaki, Shigeru [Toho Univ., Tokyo (Japan). Ohashi Hospital

    2002-08-01

    X-ray equipment has seen advances in inverters and the digitalization of reception systems. The X-ray Systems Study Group, in order to examine changes in the conditions of radiography, including pediatric radiography, variations in shortest irradiation time, and standardization of the conditions of radiography, carried out investigative research using a questionnaire survey that was sent to 400 facilities. The recovery rate was 33%. In terms of the reception system, half of the general radiography systems were using computed radiography (CR). Seventy percent of respondents used an intensifying screen and film (SEF) in stomach double-contrast radiography. About 80% used digital radiography (DR) and digital subtraction angiography (DSA) in aorta abdominalis angiography. At least 70% of high-voltage generators were of the inverter type. The conditions of radiography were not greatly influenced by changes in reception systems and X-ray equipment. Many pediatric radiographies were carried out by radiological technologists. We consider it useful to conduct such survey investigations. (author)

  16. [Report based on fiscal 2000 diagnostic x-ray equipment questionnaire survey(conditions of radiography)].

    Science.gov (United States)

    Ishikawa, Mitsuo; Matsuura, Takatoshi; Okuaki, Tomiyuki; Imai, Yoshio; Tsukamoto, Atsuko; Ide, Toshinori; Shinohara, Fuminori; Miyazaki, Shigeru

    2002-08-01

    X-ray equipment has seen advances in inverters and the digitalization of reception systems. The X-ray Systems Study Group, in order to examine changes in the conditions of radiography, including pediatric radiography, variations in shortest irradiation time, and standardization of the conditions of radiography, carried out investigative research using a questionnaire survey that was sent to 400 facilities. The recovery rate was 33%. In terms of the reception system, half of the general radiography systems were using computed radiography (CR). Seventy percent of respondents used an intensifying screen and film(S EF)in stomach double-contrast radiography. About 80% used digital radiography (DR) and digital subtraction angiography (DSA) in aorta abdominalis angiography. At least 70% of high-voltage generators were of the inverter type. The conditions of radiography were not greatly influenced by changes in reception systems and X-ray equipment. Many pediatric radiographies were carried out by radiological technologists. We consider it useful to conduct such survey investigations.

  17. Digital computed radiography in industrial X-ray testing

    International Nuclear Information System (INIS)

    Osterloh, K.; Onel, Y.; Zscherpel, U.; Ewert, U.

    2001-01-01

    Computed radiography is used for X-ray testing in many industrial applications. There are different systems depending on the application, e.g. fast systems for detection of material inhomogeneities and slower systems with higher local resolution for detection of cracks and fine details, e.g. in highly stressed areas or in welded seams. The method is more dynamic than film methods, and digital image processing is possible during testing [de

  18. Geometric estimation method for x-ray digital intraoral tomosynthesis

    Science.gov (United States)

    Li, Liang; Yang, Yao; Chen, Zhiqiang

    2016-06-01

    It is essential for accurate image reconstruction to obtain a set of parameters that describes the x-ray scanning geometry. A geometric estimation method is presented for x-ray digital intraoral tomosynthesis (DIT) in which the detector remains stationary while the x-ray source rotates. The main idea is to estimate the three-dimensional (3-D) coordinates of each shot position using at least two small opaque balls adhering to the detector surface as the positioning markers. From the radiographs containing these balls, the position of each x-ray focal spot can be calculated independently relative to the detector center no matter what kind of scanning trajectory is used. A 3-D phantom which roughly simulates DIT was designed to evaluate the performance of this method both quantitatively and qualitatively in the sense of mean square error and structural similarity. Results are also presented for real data acquired with a DIT experimental system. These results prove the validity of this geometric estimation method.

  19. Radiation exposure in X-ray angiography and comparisons between digital and conventional methods of imaging

    International Nuclear Information System (INIS)

    Schaberg, J.

    1987-01-01

    The more recent developments and techniques in the field of angiography are examined for associated radiation exposure risks for patients and investigators and then compared to the conventional methods of angiography. It could be shown that digital subtraction angiography is generally associated with a lesser risk of somatic exposure of the patient, provided that the equipment used offers an adjustable useful-beam range and focus. The fact that above-table X-ray tubes are now generally replaced with X-ray systems installed under the examination table permits the relatively high doses, to which investigators are exposed during angiography, to be reduced by a factor of 3. (DG) [de

  20. Diagnostic x-ray equipment compliance and facility survey. Recommended procedures for equipment and facility testing

    International Nuclear Information System (INIS)

    1994-01-01

    The Radiation Protection Bureau has set out guidelines for the testing of diagnostic x-ray equipment and facilities. This guide provides information for the x-ray inspector, test engineer, technologist, medical physicist and any other person responsible for verifying the regulatory compliance or safety of diagnostic x-ray equipment and facilities. Diagnostic x-radiation is an essential part of present day medical practice. The largest contributor of irradiation to the general population comes from diagnostic x-radiation. Although individual irradiations are usually small, there is a concern of possible excess cancer risk when large populations are irradiated. Unnecessary irradiations to patients from radiological procedures can be significantly reduced with little or no decrease in the value of medical diagnostic information. This can be achieved by using well designed x-ray equipment which is installed, used and maintained by trained personnel, and by the adoption of standardized procedures. In general, when patient surface dose is reduced, there is a corresponding decrease in dose to x-ray equipment operators and other health care personnel. 2 tabs., 4 figs

  1. Diagnostic x-ray equipment compliance and facility survey. Recommended procedures for equipment and facility testing

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The Radiation Protection Bureau has set out guidelines for the testing of diagnostic x-ray equipment and facilities. This guide provides information for the x-ray inspector, test engineer, technologist, medical physicist and any other person responsible for verifying the regulatory compliance or safety of diagnostic x-ray equipment and facilities. Diagnostic x-radiation is an essential part of present day medical practice. The largest contributor of irradiation to the general population comes from diagnostic x-radiation. Although individual irradiations are usually small, there is a concern of possible excess cancer risk when large populations are irradiated. Unnecessary irradiations to patients from radiological procedures can be significantly reduced with little or no decrease in the value of medical diagnostic information. This can be achieved by using well designed x-ray equipment which is installed, used and maintained by trained personnel, and by the adoption of standardized procedures. In general, when patient surface dose is reduced, there is a corresponding decrease in dose to x-ray equipment operators and other health care personnel. 2 tabs., 4 figs.

  2. Constancy check of beam quality in conventional diagnostic X-ray equipment

    International Nuclear Information System (INIS)

    Costa, Alessandro M.; Badin, Romulo S.; Leite, Marina S.; Caldas, Linda V.E.

    2008-01-01

    A tandem ionization chamber was developed for quality control programs of X-ray equipment used in conventional radiography and mammography. A methodology for the use of the tandem chamber in the constancy check of diagnostic X-ray beam qualities was established. The application at a medical X-ray imaging facility of this established methodology is presented. The use of the tandem chamber in the constancy check of diagnostic X-ray beam qualities is a useful method to control the performance of the X-ray equipment

  3. Digital Dental X-ray Database for Caries Screening

    Science.gov (United States)

    Rad, Abdolvahab Ehsani; Rahim, Mohd Shafry Mohd; Rehman, Amjad; Saba, Tanzila

    2016-06-01

    Standard database is the essential requirement to compare the performance of image analysis techniques. Hence the main issue in dental image analysis is the lack of available image database which is provided in this paper. Periapical dental X-ray images which are suitable for any analysis and approved by many dental experts are collected. This type of dental radiograph imaging is common and inexpensive, which is normally used for dental disease diagnosis and abnormalities detection. Database contains 120 various Periapical X-ray images from top to bottom jaw. Dental digital database is constructed to provide the source for researchers to use and compare the image analysis techniques and improve or manipulate the performance of each technique.

  4. Development of portable X-ray diffractometer equipped with X-ray fluorescence spectrometer and its application to archaeology

    International Nuclear Information System (INIS)

    Yamashita, Daisuke; Ishizaki, Atsushi; Uda, Masayuki

    2009-01-01

    A portable X-ray diffractometer equipped with an X-ray fluorescence spectrometer was improved so as to obtain a diffraction pattern and a fluorescence spectrum in air from one and the same small area of a specimen. The reason why the portable XRD with an XRF spectrometer was specially designed for archaeology may be understood from the following facts: (1) some objects exhibited in museums are not allowed to be transferred from the open air to a vacuum, even if their volumes are small; (2) some objects are very difficult to move from their original sites; (3) some parts of exhibits are extremely fragile and cannot be examined in a vacuum; and (4) information on the chemical composition and structure from the same area of an object offers a better understanding of the constitutive materials of the object. Some examples of the use of a portable X-ray diffractometer equipped with an X-ray fluorescence spectrometer in the field are also introduced. Experimental results of Sho-kannon, Snew's mask and Tutankhamun's golden mask are shown here. (author)

  5. Multiframe digitization of x-ray (TV) images (abstract)

    Science.gov (United States)

    Karpenko, V. A.; Khil'chenko, A. D.; Lysenko, A. P.; Panchenko, V. E.

    1989-07-01

    The work in progress deals with the experimental search for a technique of digitizing x-ray TV images. The small volume of the buffer memory of the analog-to-digital (A/D) converter (ADC) we have previously used to detect TV signals made it necessary to digitize only one line at a time of the television raster and also to make use of gating to gain the video information contained in the whole frame. This paper is devoted to multiframe digitizing. The recorder of video signals comprises a broadband 8-bit A/D converter, a buffer memory having 128K words and a control circuit which forms a necessary sequence of advance pulses for the A/D converter and the memory relative to the input frame and line sync pulses (FSP and LSP). The device provides recording of video signals corresponding to one or a few frames following one after another, or to their fragments. The control circuit is responsible for the separation of the required fragment of the TV image. When loading the limit registers, the following input parameters of the control circuit are set: the skipping of a definite number of lines after the next FSP, the number of the lines of recording inside a fragment, the frequency of the information lines inside a fragment, the delay in the start of the ADC conversion relative to the arrival of the LSP, the length of the information section of a line, and the frequency of taking the readouts in a line. In addition, among the instructions given are the number of frames of recording and the frequency of their sequence. Thus, the A/D converter operates only inside a given fragment of the TV image. The information is introduced into the memory in sequence, fragment by fragment, without skipping and is then extracted as samples according to the addresses needed for representation in the required form, and processing. The video signal recorder governs the shortest time of the ADC conversion per point of 250 ns. As before, among the apparatus used were an image vidicon with

  6. X-ray Digital Linear Tomosynthesis Imaging for Artificial Pulmonary Nodule Detection

    Directory of Open Access Journals (Sweden)

    Tsutomu Gomi

    2011-01-01

    Full Text Available The purpose of this paper is to identify indications for volumetric X-ray digital linear tomosynthesis (DLT with single- and dual-energy subtraction techniques for artificial pulmonary nodule detection and compare X-ray DLT, X-ray digital radiography, and computed tomography.

  7. Problems and image processing in X-ray film digitization

    International Nuclear Information System (INIS)

    Kato, Syousuke; Yoshita, Hisashi; Kuranishi, Makoto; Itoh, Hajime; Mori, Kouichi; Konishi, Minoru

    1992-01-01

    Aiming at the realization of PACS, a study was conducted on the present state of, and various problems associated with, X-ray film digitization using a He-Ne laser-type film digitizer. Image quality was evaluated physically and clinically. With regard to the gradation specificity, the linear specificity was shown in a dynamic range of 4 figures. With regard to resolution specificity, visual evaluation was performed using a Hawlet Chart, with almost no difference being found between the CRT and laser printer output images and the decrease in resolution becoming more pronounced as the sampling pitch became greater. Clinical evaluation was performed with reference to the literature. The general evaluation of the clinicians was that although there was some deterioration for all of the shadows, (I have read this many times, but could not understand the last part.) by performing each of the kinds of image-processing enhancement of diagnostic ability was achieved, with a diagnosis being possible. The problem of unhindered diagnosis due to the development of artifacts from optical interference of the grid images projected onto the clinical pictures and digitizer sampling pitch was studied. As countermeasures, the use of a high density grid and adoption of a low-pass filter were useful in impending the development of artifacts. Regarding the operating problems, the inputting of index information requires a considerable number of manhours and a method of automatic recognition from digital data was introduced to overcome this problem. As future-prospects, the concepts of a practical system of X-ray film digitization and a film-screen system adapted to digitization were described. (author)

  8. Problems and image processing in X-ray film digitization

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Syousuke; Yoshita, Hisashi; Kuranishi, Makoto; Itoh, Hajime; Mori, Kouichi; Konishi, Minoru (Toyama Medical and Pharmaceutical Univ. (Japan). Hospital)

    1992-11-01

    Aiming at the realization of PACS, a study was conducted on the present state of, and various problems associated with, X-ray film digitization using a He-Ne laser-type film digitizer. Image quality was evaluated physically and clinically. With regard to the gradation specificity, the linear specificity was shown in a dynamic range of 4 figures. With regard to resolution specificity, visual evaluation was performed using a Hawlet Chart, with almost no difference being found between the CRT and laser printer output images and the decrease in resolution becoming more pronounced as the sampling pitch became greater. Clinical evaluation was performed with reference to the literature. The general evaluation of the clinicians was that although there was some deterioration for all of the shadows, (I have read this many times, but could not understand the last part.) by performing each of the kinds of image-processing enhancement of diagnostic ability was achieved, with a diagnosis being possible. The problem of unhindered diagnosis due to the development of artifacts from optical interference of the grid images projected onto the clinical pictures and digitizer sampling pitch was studied. As countermeasures, the use of a high density grid and adoption of a low-pass filter were useful in impending the development of artifacts. Regarding the operating problems, the inputting of index information requires a considerable number of manhours and a method of automatic recognition from digital data was introduced to overcome this problem. As future-prospects, the concepts of a practical system of X-ray film digitization and a film-screen system adapted to digitization were described. (author).

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

    International Nuclear Information System (INIS)

    Lee, Sang Sub; Kwon, Hyok Rak; Sim, Woo Hyoun; Oh, Seung Hyoun; Lee, Ji Youn; Jeon, Kug Jin; Kim, Kee Deog; Park, Chang Seo

    2000-01-01

    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.

  10. Quality control measurements for digital x-ray detectors

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, N W [Department of Radiology, University Hospitals Leuven, 49 Herenstraat, 3000 Leuven (Belgium); Mackenzie, A [National Co-ordinating Centre for the Physics of Mammography, Medical Physics, Level B, St Luke' s Wing, The Royal Surrey County Hospital NHS Trust, Egerton Road, Guildford, GU2 7XX (United Kingdom); Honey, I D, E-mail: nicholas.marshall@uz.kuleuven.ac.be [Department of Medical Physics, Floor 3, Henriette Raphael House, Guy' s and St Thomas' Hospital, London, SE1 9RT (United Kingdom)

    2011-02-21

    This paper describes a digital radiography (DR) quality control protocol for DR detectors from the forthcoming report from the Institute of Physics and Engineering in Medicine (IPEM). The protocol was applied to a group of six identical caesium iodide (CsI) digital x-ray detectors to assess reproducibility of methods, while four further detectors were assessed to examine the wider applicability. Twelve images with minimal spatial frequency processing are required, from which the detector response, lag, modulation transfer function (MTF), normalized noise power spectrum (NNPS) and threshold contrast-detail (c-d) detectability are calculated. The x-ray spectrum used was 70 kV and 1 mm added copper filtration, with a target detector air kerma of 2.5 {mu}Gy for the NNPS and c-d results. In order to compare detector performance with previous imaging technology, c-d data from four screen/film systems were also acquired, at a target optical density of 1.5 and an average detector air kerma of 2.56 {mu}Gy. The DR detector images were typically acquired in 20 min, with a further 45 min required for image transfer and analysis. The average spatial frequency for the 50% point of the MTF for six identical detectors was 1.29 mm{sup -1} {+-} 0.05 (3.9% coefficient of variation (cov)). The air kerma set for the six systems was 2.57 {mu}Gy {+-} 0.13 (5.0% cov) and the NNPS at this air kerma was 1.42 x 10{sup -5} mm{sup 2} (6.5% cov). The detective quantum efficiency (DQE) measured for the six identical detectors was 0.60 at 0.5 mm{sup -1}, with a maximum cov of 10% at 2.9 mm{sup -1}, while the average DQE was 0.56 at 0.5 mm{sup -1} for three CsI detectors from three different manufacturers. Comparable c-d performance was found for these detectors (5.9% cov) with an average threshold contrast of 0.46% for 11 mm circular discs. The average threshold contrast for the S/F systems was 0.70% at 11 mm, indicating superior imaging performance for the digital systems. The protocol was found

  11. Design and construction of the Portable Industrial X-Ray Equipment

    International Nuclear Information System (INIS)

    Nguyen Phuc; Nguyen Van Si; Le Tien Quan; Trinh Anh Tuan; Nguyen Manh Hung; Trinh Dinh Tuong

    2011-01-01

    The main purposes of the project are the supporting to design and construction of the Portable Industrial X-Ray Equipment; with the accuracy ±2% of Output High Voltage 200 kV and Tube current 5 mA. The Equipment is composed of control unit, X-ray generator, and power cable, connection cable. X-ray generator is assembling construction X-ray tube, H.V transformer together with gas insulation (SF6) are sealed up in aluminum bucked cabinet, fan and heat-sink are mounted in the end of X-ray generator as cooling, SF6 is a gas electrical performance to H.V. Alarm lamp is used to warn, flashing, show generating X-ray. Control unit is box construction. Four printed circuit boards (PCB) and electronic device are mounted in it. All operating buttons switches and displays are equipped on the panel. We have completed to design and construct the Portable Industrial X-Ray Equipment; and have tested the electronic parameters of all test points and the main parameters of equipment (the accuracy ±2% of Output High Voltage 200 kV and Tube current 5 mA). We also have successful used the Portable Industrial X-Ray Equipment to evaluate the welds in industry. (author)

  12. Metacarpal index by digital X-ray radiogrammetry: normative reference values and comparison with dual X-ray absorptiometry

    DEFF Research Database (Denmark)

    Hyldstrup, Lars; Nielsen, S P

    2001-01-01

    Metacarpal index (MCI), the combined cortical midmetacarpal thickness divided by the outer mid-metacarpal diameter, fell into oblivion when dual photon absorptiometry was introduced a quarter of a century ago. Modern PC-based digital X-ray diameter measurements offers a unique opportunity...

  13. Evaluation and characterization of digital X-ray equipment for paediatric cardiology in the Hospital Gregorio Maranon; Evaluacion y caracterizacion de la dinamica de trabajo y de la dosis recibida por el paciente en la sala de hemodinamica infantil del Hospital General Universitario Gregorio Maranon

    Energy Technology Data Exchange (ETDEWEB)

    Calama Santiago, J. A.; Gonzalez Ruiz, C.; Infante Utrilla, M. A.; Zanfano Hidalgo, R.; Penedo cobos, J. M.; Sierra Diaz, F.; Olivares Munoz, M. P.

    2006-07-01

    The purchase of a digital X-Ray equipment specific for paediatric cardiology in 2003 has allowed a careful examination of the technical characteristics of these patients. This data review includes the analysis of a dose index with several variable factors such as weight, size and age of patients, purpose, type and characteristics of the study and its development over time as a results of the experience gained by the staff involved. (Author)

  14. Digital optical correlator x-ray telescope alignment monitoring system

    Science.gov (United States)

    Lis, Tomasz; Gaskin, Jessica; Jasper, John; Gregory, Don A.

    2018-01-01

    The High-Energy Replicated Optics to Explore the Sun (HEROES) program is a balloon-borne x-ray telescope mission to observe hard x-rays (˜20 to 70 keV) from the sun and multiple astrophysical targets. The payload consists of eight mirror modules with a total of 114 optics that are mounted on a 6-m-long optical bench. Each mirror module is complemented by a high-pressure xenon gas scintillation proportional counter. Attached to the payload is a camera that acquires star fields and then matches the acquired field to star maps to determine the pointing of the optical bench. Slight misalignments between the star camera, the optical bench, and the telescope elements attached to the optical bench may occur during flight due to mechanical shifts, thermal gradients, and gravitational effects. These misalignments can result in diminished imaging and reduced photon collection efficiency. To monitor these misalignments during flight, a supplementary Bench Alignment Monitoring System (BAMS) was added to the payload. BAMS hardware comprises two cameras mounted directly to the optical bench and rings of light-emitting diodes (LEDs) mounted onto the telescope components. The LEDs in these rings are mounted in a predefined, asymmetric pattern, and their positions are tracked using an optical/digital correlator. The BAMS analysis software is a digital adaption of an optical joint transform correlator. The aim is to enhance the observational proficiency of HEROES while providing insight into the magnitude of mechanically and thermally induced misalignments during flight. Results from a preflight test of the system are reported.

  15. Order No. 217 of 29 April 1977 on X-ray diagnostic equipment for medical use

    International Nuclear Information System (INIS)

    1978-01-01

    This Order was made by the National Health Service and is divided into several parts covering inter alia approval and notification of X-ray installations, conditions of liability, occupational radiation protection, construction of X-ray apparatus and its shielding and inspection of such equipment by the National Health Service. (NEA) [fr

  16. Performance of X-ray equipment used for conventional radiographic examinations of children

    International Nuclear Information System (INIS)

    Lacerda, Marco A.S.; Silva, Teogenes A. da; Khoury, Helen J.

    2009-01-01

    The performance of X-ray equipment that are used for conventional X-ray examinations of children in four hospitals of Belo Horizonte, Brazil, was evaluated. The methodology proposed by the Brazilian authority for radiation protection in diagnostic radiology was adopted. The performance tests were carried out in six X-ray machines and they consisted of measurements and determination of the X-ray tube output, linearity and constancy of radiation output, accuracy and reproducibility of the exposure time and tube potential, half-value layer (HVL), light field / X-ray field alignment and accuracy of the X-ray field indicator. It was observed that only one hospital had the suitable equipment for X-ray examinations of children. Results showed that all six equipment of the four hospitals presented unsatisfactory performance in some quality control tests. Only for some combinations of the exposure parameters, generally employed in pediatric X-ray examinations, some equipment complied with the authority requirements. (author)

  17. [2011 Shanghai customer satisfaction report of DSA/X-ray equipment's after-service].

    Science.gov (United States)

    Li, Bin; Qian, Jianguo; Cao, Shaoping; Zheng, Yunxin; Xu, Zitian; Wang, Lijun

    2012-11-01

    To improve the manufacturer's medical equipment after-sale service, the fifth Shanghai zone customer satisfaction survey was launched by the end of 2011. The DSA/X-ray equipment was setup as an independent category for the first time. From the survey we can show that the DSA/X-ray equipment's CSI is higher than last year, the customer satisfaction scores of preventive maintenance and service contract are lower than others, and CSI of local brand is lower than imported brand.

  18. Code of Practice for Protection Against Ionizing Radiation Emitted from X-ray Analysis Equipment (1984)

    International Nuclear Information System (INIS)

    1984-01-01

    Appropriate working rules, safety features and monitoring requirements for general X-ray analysis units or equipment are laid down in this Code which is intended for users of such equipment. The Code advises that establishments draw up their own working procedures based on appropriate legislation and on the recommendations contained in this Code. The Code also describes the requirements for X-ray analysis equipment necessary to ensure safety. (NEA) [fr

  19. Controlled area for mobile medical X-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, B; Taschner, P; Koenig, W [Staatliches Amt fuer Atomsicherheit und Strahlenschutz, Berlin (German Democratic Republic); Fuehr, K P; Kucharz, R [Rostock Univ. (German Democratic Republic). Radiologische Klinik

    1976-10-01

    On the basis of dose rate measurements the radiation protection situation during operation of mobile X-ray machines is described. According to these results, the controlled area has been definitely fixed by the National Board of Nuclear Safety and Radiation Protection with respect to the following fields of application: stomatology, mobile radiography of patients confined to bed as well as performing radiological examinations in the operating theatre.

  20. Measurement of scattered and transmitted X-rays from intra-oral and panoramic dental X-ray equipment.

    Science.gov (United States)

    Holroyd, John Richard

    2018-04-10

    To quantify the levels of transmitted radiation arising from the use of intra-oral dental X-ray equipment and scattered radiation arising from the use of both intra-oral and panoramic X-ray equipment. Methods: Levels of scattered radiation were measured at 1 m from a phantom, using an 1800 cc ion chamber. Transmitted radiation was measured using both: i) a phantom and Dose Area Product (DAP) meter, ii) a patient and an 1800 cc ion chamber. Results: For intra-oral radiography the patient study gave a maximum transmission of 1.80% (range 0.04% to 1.80%, mean 0.26%) and the phantom study gave a maximum transmission of 6% (range 2% to 6%, mean 5%). The maximum scattered radiation, per unit DAP, was 5.5 nGy (mGy cm2)-1 at 70 kVp and a distance of 1 m. For panoramic radiography the maximum scattered radiation was 9.3 nGy (mGy cm2)-1 at 80 kVp and a distance of 1 m. Conclusions: Typical doses from scattered and transmitted radiation in modern dental practice have been measured and values are presented to enable the calculation of adequate protection measures for dental radiography rooms. Advances in knowledge: Previous studies have used a phantom and measured radiation doses at 1 m from the phantom to determine the radiation dose transmitted through a patient, whereas this study uses both patient and phantom measurements together with a large area dose meter, positioned to capture the entire X-ray beam, to ensure more realistic dose measurements can be made. © 2018 IOP Publishing Ltd.

  1. Accidental exposure with X-ray diffraction equipment

    International Nuclear Information System (INIS)

    Montanez, O.; Blanco, D.

    1991-01-01

    The shutter on one of the windows of an X-ray diffraction apparatus was accidentally left open, exposing the worker to the radiation. The worker was wearing a dosimeter film, which was processed immediately to evaluate the potential risk. It was determined that the exposure rate was 350 Roentgen/minute on the skin surface, with corrections being made for the worker's thin clothing. It was concluded that in spite of the worker receiving a relative high dose, it did not reach the threshold value for producing deterministic effects such as cataracts, erythema, and skin damage

  2. The parameters of X-ray equipment that influence in patient exposure

    International Nuclear Information System (INIS)

    Peixoto, J.E.

    1988-01-01

    The main components of the X-rays equipment and the secondary device for radiodiagnosis examination are showed. The influence of all radiographs parameters in human exposure as tension and current are also analysed. (C.G.C.) [pt

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  4. Recommended safety procedures for the selection, installation and use of baggage inspection x-ray equipment

    International Nuclear Information System (INIS)

    1978-05-01

    Good X-ray equipment alone will not preclude unnecessary exposure to x-radiation. The equipment must be installed, maintained and used by adequately trained personnel, with due regard for the inherent hazards of such equipment and an appreciation of the need to observe proper operational procedures. It is the intent of this Code to define equipment specifications and conditions of installation and use for baggage inspection X-ray equipment, such that the hazard to operating personnel and the general public from such devices remains negligibly small. (auth)

  5. Portable pulsed X-ray digital radiographic system based on network transmission

    International Nuclear Information System (INIS)

    Tang Le; Li Yuanjing; Wang Yi; Cheng Jianping

    2004-01-01

    Network communication technology of TCP/IP protocol serves as application in pulse X-ray digital radiography system. The system radiographs synchronously with pulse X-ray and converts image signals to digital data, which are transmitted to computer for displaying and processing in network. The system composing structures are present and portable and other characteristics are introduced. (authors)

  6. Compression of the digitized X-ray images

    International Nuclear Information System (INIS)

    Terae, Satoshi; Miyasaka, Kazuo; Fujita, Nobuyuki; Takamura, Akio; Irie, Goro; Inamura, Kiyonari.

    1987-01-01

    Medical images are using an increased amount of space in the hospitals, while they are not accessed easily. Thus, suitable data filing system and precise data compression will be necessitated. Image quality was evaluated before and after image data compression, using local filing system (MediFile 1000, NEC Co.) and forty-seven modes of compression parameter. For this study X-ray images of 10 plain radiographs and 7 contrast examinations were digitized using a film reader of CCD sensor in MediFile 1000. Those images were compressed into forty-seven kinds of image data to save in an optical disc and then the compressed images were reconstructed. Each reconstructed image was compared with non-compressed images in respect to several regions of our interest by four radiologists. Compression and extension of radiological images were promptly made by employing the local filing system. Image quality was much more affected by the ratio of data compression than by the mode of parameter itself. In another word, the higher compression ratio became, the worse the image quality were. However, image quality was not significantly degraded until the compression ratio was about 15: 1 on plain radiographs and about 8: 1 on contrast studies. Image compression by this technique will be admitted by diagnostic radiology. (author)

  7. Evaluation of body simulator for chest and abdomen in digital X-ray equipment; Avaliação de simulador de corpo para regiões do tórax e abdômen em equipamento de raios-X digital

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Sidney S.; Cardoso, Gabriela P.; Oliveira, Giovanni Antônio P.; Batista, Adriana S.M., E-mail: sidneyss70soares@gmail.com, E-mail: gabrielapontesc@gmail.com, E-mail: giovanni.paiva@pbh.gov.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Anatomia e Imagem; Pereira, Esther Lorrayne M., E-mail: esther_machado@outlook.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2017-07-01

    The use of body simulators to control the quality of X-ray images is a practice that guarantees the control of essential parameters for diagnosis by the technique. The evolution of the equipment, between the analogue, digital computerized radiology (CR) and direct radiography (DR), requires evaluation of the equivalence in grayscale, of simulators, for an adjustment according to the specific technology of obtaining the image. In this sense, the present work presents the evaluation of a body simulator with regard to the representation of mean values of signal, noise and contrast obtained in chest radiographs and panoramic of the abdomen. For the thorax the cardiac region was considered as simulation target and for the abdomen simulation of the liver and small intestine. We used a retrospective study of images obtained with X-ray equipment - CR system, in which the images were studied using the ImageJ program, generating a data catalog. These were subsequently compared with those obtained experimentally using gel filled polymer body simulator. For the validation of the simulator, it was observed the gel equivalence of filling of the polymer box required to reach the image parameters of the cataloged radiographs. The results are discussed as to the physical principles of radiation interaction with biological and equivalent tissues.

  8. Digital image analysis of X-ray television with an image digitizer

    International Nuclear Information System (INIS)

    Mochizuki, Yasuo; Akaike, Hisahiko; Ogawa, Hitoshi; Kyuma, Yukishige

    1995-01-01

    When video signals of X-ray fluoroscopy were transformed from analog-to-digital ones with an image digitizer, their digital characteristic curves, pre-sampling MTF's and digital Wiener spectral could be measured. This method was advant ageous in that it was able to carry out data sampling because the pixel values inputted could be verified on a CRT. The system of image analysis by this method is inexpensive and effective in evaluating the image quality of digital system. Also, it is expected that this method can be used as a tool for learning the measurement techniques and physical characteristics of digital image quality effectively. (author)

  9. Lists A and B of X-ray equipment. As of July 1, 1984

    International Nuclear Information System (INIS)

    1984-01-01

    The lists A and B of X-ray equipment present the guidelines for X-ray device, as of December 10, 1983, that are defined in the guidelines for radiology and nuclear medicine of the Federal Association of Panel Doctors. In list A, the equipment categories of up-to-date, commercially available X-ray device are given, whereas list B classifies older equipment, both types available from manufacturers who are members of the ZVEI association. Since the categories of application II and III have been made, specifiying the equipment still in use and applicable within a given transitional period in existing medical establishments, but which may not be applied in new establishments. The list of manufacturers gives the addresses of the firms supplying the equipment described in Lists A and B, which have been compiled according to the requirements set by the Federal Association of Panel Doctors. (orig.) [de

  10. Development of a dosimetric system for dental X-ray equipment quality control

    International Nuclear Information System (INIS)

    Melo, Francisco Almeida de

    2002-08-01

    An electronic instrument with digital readout was designed and constructed to provide fast, simple and non-invasive measurements of X-ray dental equipment parameters. This instrument is capable of evaluating the entrance dose, exposure time, tube voltage (kVp) and beam filtration. It consists of a set of five photodiodes connected each one in the photocurrent mode to the input of a designed integrating electrometer. Three of the detectors are fixed under aluminium filters with different thicknesses, one is fixed under a 0.3 mm copper filter and the other has no filtration. The readings of the three detectors under aluminium filters and of the bare detector permit the determination of the half-value layer, which is used to calculate the beam filtration. The ratio between the readings of the detector below the copper filter and the one without filtration is used to determine the tube voltage. The signal produced by the detector without filter is used to evaluate the patient entrance dose, and to active an electronic timer for measuring the real exposure time. The tests and calibration of the instrument in different voltages in the 59 - 70kVp range, showed that its response is both stable and reproducible to within 1%. The instrument response was compared to the one from a commercial non-invasive X-ray test equipment (Gammex RMI Multifunction kVp meter). The results showed that the response of the developed instrument is in good agreement with the RMI meter which is the standard equipment for such measurements. These results indicate that the dosimetric system is suitable for use in Dental Quality Assurance Programs. (author)

  11. Position statement on use of hand-held portable dental X-ray equipment

    International Nuclear Information System (INIS)

    2014-06-01

    The position statement focuses on justification in the medical field, in particular on the use of hand-held portable dental x-ray equipment. It supplements another HERCA position paper, providing a general overview of the use of all hand-held portable X-ray equipment. Key Messages: - HERCA finds that the use of hand-held portable X-ray devices should be discouraged except in special circumstances. - As a general rule, these devices should only be used in scenarios where an intraoral radiograph is deemed necessary for a patient and the use of a fixed or semi-mobile x-ray unit is impractical, e.g.: - nursing homes, residential care facilities or homes for persons with disabilities; - forensic odontology, - military operations abroad without dental facilities

  12. New methodology to measure kVp in X-rays equipment for radiodiagnosis

    International Nuclear Information System (INIS)

    Vega Ramirez, J.L.; Pela, C.A.

    1998-01-01

    The work aims to obtain through experiments a spaced out sensibilization (different optical densities) in the X-rays film by letting X-rays photons go through a metallic layer of copper with tiers with different thickness that can cover the range of kVps employed in radiological tests. Results for the kVp shown here were also compared with other equipment available in the market. Comparisons showed their similarity but have also the advantage of being cheap and viable

  13. The introduction of compulsory compliance testing of medical diagnostic x-ray equipment in Western Australia

    International Nuclear Information System (INIS)

    Rafferty, M. W.; Jacob, C. S.

    1995-01-01

    Performance testing of medical diagnostic X-ray equipment can reveal equipment faults which, while not always clinically detectable, may contribute to reduced image quality and unnecessary radiation exposure of both patients and staff. Routine testing of such equipment is highly desirable to identify such faults and allows them to be rectified. The Radiological council of Western Australia is moving towards requiring compulsory compliance testing of all (new and existing) medical diagnostic X-ray equipment that all new mobile radiographic and new mammographic X-ray equipment be issued with a compliance test certificate as a prerequisite for registration. Workbooks which provide details of the tests required and recommended test methods have been prepared for medical radiographic (mobile and fixed), fluoroscopic and mammographic X-ray equipment. It is intended that future workbooks include details of the tests and methods for dental and computed tomography X-ray units. The workbooks are not limited to the compliance testing of items as specified in the Regulations, but include tests for other items such as film processing, darkrooms and image quality (for fluoroscopic equipment). Many of the workbook tests could be used within a regular quality assurance program for diagnostic X-ray equipment. Persons who conduct such compliance tests will need to be licensed and have all test certificates endorsed by a qualified expert. Suitable training and assessment of compliance testers will be required. Notification of such tests (including non-compliant items and corrective actions taken) will be required by the Radiological Council as a condition of equipment registration. 9 refs

  14. Quality control of diagnostic x-ray equipment and film processing

    International Nuclear Information System (INIS)

    1993-01-01

    According to the section 40 of the Radiation Act (592/92), the licensee is required in Finland to make the arrangements to control the function of the radiation equipment and related facilities used for medical procedures. The guide explains how quality control can be organized for diagnostic x-ray equipment. It also gives recommendations for constancy tests for conventional x-ray radiographic and fluoroscopic equipment and for film processing. The recommendations are based on the publications and statements of the International Committee for Radiation Protection (ICRP) and standardization organizations. The intention is that the operators of x-ray equipment or the maintenance personnel are able to perform the quality control tests presented in the guide

  15. On the methods of determination of x-ray sources protection quality in x-ray diagnostic equipment

    International Nuclear Information System (INIS)

    Vladimirov, L.V.

    1973-01-01

    Existing procedures for assessing the quality of shielding of X-ray radiators are compared; these procedures are shown to have a number of shortcomings and to be very time-consuming. A procedure is offered in which shielding quality is tested in two stages: (1) X-ray tests aimed at determining the quality of protection of the X-ray tube unit; and (2) dosimeter tests proper. The results of measurements are compared with maximum permissible dosage rate

  16. Evaluation of dimensions of diagnostic X-ray tube focal spots using direct digitalization

    International Nuclear Information System (INIS)

    Costa, Paulo R.; Furquim, Tania A.C.

    1996-01-01

    An image digitalization system is proposed as an alternative method for replacing direct exposure X-ray films on the evaluation of dimensions of diagnostic X-ray tube focal spots. Results of measurements are presented and compared to nominal values

  17. Database application of digital medical X-rays and labs: computerization, storage, retrieval, interpretation, and distribution.

    Science.gov (United States)

    Hatcher, Myron; Tabriziani, Hossein; Heetebry, Irene

    2005-08-01

    Stenter lets the health care worker order an X-ray that is produced as a computer image rather than on flat film. The health care provider can be in any location with the correct equipment, and view the digital image. The dimensions of this discussion are extensive. The cost savings because of reduced media and storage cost is substantial. Health care quality can be improved because of the ability to obtain consultation via telemedicine and the enhanced ability to track medical problems over time via trends. The major downside is the limited cost imbursement system to pay for technology. Unfortunately, this may impact on the improved quality of care. In simple terms someone needs to pay for the technology and the quality of health care needs to be maintained or improved. The real cost to the health care systems needs to be correctly calculated and inappropriate charging kept to a minimum. Specific costs need to be kept in mind and the first is the cost for new staff or staff training. The number of health care providers that are able to read the X-ray can be enlarged remembering that only American Board Certified Radiologists are allowed to give the final recommendation. How do we view the cost of missing something? It could be argued that this risk will be reduced because of improved technology for obtaining the digital X-ray and improved enhancement software. One way to view this situation is to include technology, management, and organization. The cost and benefits occur through the interplay of all three dimensions. The development of digital imaging hardware and artificial intelligence software will demand change in the management and organization. The organization will require changes in its design to accommodate the technology as to support and resources. Management will evolve to include methods for control and monitoring this technology. Business processes and standard operating procedures will change to integrate the technology into the organization in

  18. X-Ray, Digital Imaging with Volumetric Density Measurement and Profiling, Applied to the Characterization of Waste Drums

    International Nuclear Information System (INIS)

    Huhtiniemi, I.; Gupta, N.; Halliwell, S.

    2006-01-01

    The European Commission's Joint Research Centre Ispra Site (JRC-Ispra) has initiated a decommissioning and waste management program that will span about two decades. The program includes a requirement to characterize the contents of about 6,500 radioactive, 220 litre waste drums whose documented history is incomplete. To render the characterization process more efficient, the drums will be initially divided into homogeneous groups, an activity that will be based on existing documentation and non-destructive examination (NDE) by X-ray digital imaging. This paper describes the X-ray imaging techniques chosen, and the planned performance validation of the equipment. (authors)

  19. X-ray Phase Contrast analysis - Digital wavefront development

    International Nuclear Information System (INIS)

    Idir, Mourad; Potier, Jonathan; Fricker, Sebastien; Snigirev, Anatoly; Snigireva, Irina; Modi, M. H.

    2010-01-01

    Optical schemes that enable imaging of the phase shift produced by an object have become popular in the x-ray region, where phase can be the dominant contrast mechanism. The propagation-based technique consists of recording the interference pattern produced by choosing one or several sample-to-detector distances. Pioneering studies, carried out making use of synchrotron radiation, demonstrated that this technique results in a dramatic increase of image contrast and detail visibility, allowing the detection of structures invisible with conventional techniques. An experimental and theoretical study of in-line hard x-ray phase-contrast imaging had been performed. The theoretical description of the technique is based on Fresnel diffraction. As an illustration of the potential of this quantitative imaging technique, high-resolution x-ray phase contrast images of simple objects will be presented.

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

    Science.gov (United States)

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

    2012-12-01

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

  1. Analysis of environmental impact assessment for large-scale X-ray medical equipments

    International Nuclear Information System (INIS)

    Fu Jin; Pei Chengkai

    2011-01-01

    Based on an Environmental Impact Assessment (EIA) project, this paper elaborates the basic analysis essentials of EIA for the sales project of large-scale X-ray medical equipment, and provides the analysis procedure of environmental impact and dose estimation method under normal and accident conditions. The key points of EIA for the sales project of large-scale X-ray medical equipment include the determination of pollution factor and management limit value according to the project's actual situation, the utilization of various methods of assessment and prediction such as analogy, actual measurement and calculation to analyze, monitor, calculate and predict the pollution during normal and accident condition. (authors)

  2. Usefulness of inverter type REX-650 R/F X-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Min; Oh, Jung Hwan [College of Health Sceince, Korea University, Seoul (Korea, Republic of)

    2003-06-15

    The conclusions after appraisal usefulness of Korean 30 kHz inverter type X-ray equipment which are currently used in the clinics are like those followings. The specific characters of mA, kVp, msec in the radiography keep very good accuracy and showed good waveform also under KS regulations. The output of the X-ray equipment is showed 1.7 times higher than single-phase. mA, kVp of the fluoroscopy and Sopt film exposure mA, kVp showed appropriated result under the regulations. As we consider the conversion factor of image intensifier tube used for two years, it showed pretty high results, 310 at 75 kV, and knew that the conversion factor which followed by increasing kVp increased its computations like Kim's experimentation. Those X-ray equipment showed excellent results in the appraisal while those were operating so we think that those X-ray equipment will be substitute for expensive foreign equipment in Korean domestic medical equipment in the future.

  3. Automated and observer based light field indicator edge evaluation in diagnostic X-ray equipment

    Directory of Open Access Journals (Sweden)

    Márcio Bottaro

    Full Text Available Abstract Introduction To analyze edge detection and optical contrast calculation of light field-indicators used in X-ray via automated- and observer-based methods, and comparison with current standard approaches, which do not give exact definition for light field edge determination. Methods Automated light sensor array was used to measure the penumbra zone of the edge in the standard X-ray equipment, while trained and naïve human observers were asked to mark the light field edge according to their own determination. Different interpretations of the contrast were then calculated and compared. Results In contrast to automated measurements of edge definition and detection, measurements by human observers showed large inter-observer variation independent of their training with X-ray equipment. Different contrast calculations considering the different edge definitions gave very different contrast values. Conclusion As the main conclusion, we propose a more exact edge definition of the X-ray light field, corresponding well to the average human observer’s edge determination. The new edge definition method with automated systems would reduce human variability in edge determination. Such errors could potentially affect the approval of X-ray equipment, and also increase the radiation dose. The automated measurement based on human observers’ edge definition and the corresponding contrast calculation may lead to a more precise light field calibration, which enables reduced irradiation doses on radiology patients.

  4. Automated and observer based light field indicator edge evaluation in diagnostic X-ray equipment

    International Nuclear Information System (INIS)

    Bottaro, Marcio; Nagy, Balazs Vince; Soares, Fernanda Cristina Salvador; Rosendo, Danilo Cabral

    2017-01-01

    Introduction: To analyze edge detection and optical contrast calculation of light field-indicators used in X-ray via automated- and observer-based methods, and comparison with current standard approaches, which do not give exact definition for light field edge determination. Methods: Automated light sensor array was used to measure the penumbra zone of the edge in the standard X-ray equipment, while trained and naive human observers were asked to mark the light field edge according to their own determination. Different interpretations of the contrast were then calculated and compared. Results: In contrast to automated measurements of edge definition and detection, measurements by human observers showed large inter-observer variation independent of their training with X-ray equipment. Different contrast calculations considering the different edge definitions gave very different contrast values. Conclusion: As the main conclusion, we propose a more exact edge definition of the X-ray light field, corresponding well to the average human observer's edge determination. The new edge definition method with automated systems would reduce human variability in edge determination. Such errors could potentially affect the approval of X-ray equipment, and also increase the radiation dose. The automated measurement based on human observers’ edge definition and the corresponding contrast calculation may lead to a more precise light field calibration, which enables reduced irradiation doses on radiology patients. (author)

  5. Automated and observer based light field indicator edge evaluation in diagnostic X-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Bottaro, Marcio; Nagy, Balazs Vince; Soares, Fernanda Cristina Salvador; Rosendo, Danilo Cabral, E-mail: marcio@iee.usp.br [Universidade de Sao Paulo (USP), SP (Brazil); Optics and Engineering Informatics, Budapest University of Technology and Economics, Budapest (Hungary)

    2017-04-15

    Introduction: To analyze edge detection and optical contrast calculation of light field-indicators used in X-ray via automated- and observer-based methods, and comparison with current standard approaches, which do not give exact definition for light field edge determination. Methods: Automated light sensor array was used to measure the penumbra zone of the edge in the standard X-ray equipment, while trained and naive human observers were asked to mark the light field edge according to their own determination. Different interpretations of the contrast were then calculated and compared. Results: In contrast to automated measurements of edge definition and detection, measurements by human observers showed large inter-observer variation independent of their training with X-ray equipment. Different contrast calculations considering the different edge definitions gave very different contrast values. Conclusion: As the main conclusion, we propose a more exact edge definition of the X-ray light field, corresponding well to the average human observer's edge determination. The new edge definition method with automated systems would reduce human variability in edge determination. Such errors could potentially affect the approval of X-ray equipment, and also increase the radiation dose. The automated measurement based on human observers’ edge definition and the corresponding contrast calculation may lead to a more precise light field calibration, which enables reduced irradiation doses on radiology patients. (author)

  6. Determination of the size of X-ray tube focal spots: direct digitalization vs optical evaluation

    International Nuclear Information System (INIS)

    Furquim, Tania A.C.; Yanikian, Denise; Costa, Paulo R.

    1996-01-01

    A comparative study between standard techniques for evaluation of X-ray tubes focal spots and a newer one which uses digital resources for image acquisition is presented. Results from measurements by using both methods are presented

  7. Comarability of digital and analouge x-rays for migration measurements with EBRA

    International Nuclear Information System (INIS)

    Brabec, E.

    2001-02-01

    EBRA is a computer supported method for measuring the migration of total hip prostheses by using consecutive standard X-rays of the pelvis. PACS is a picture archiving and communication system used to handle digitally taken X-rays. After the installation of a PACS at the University Clinic of Innsbruck it was impossible to compare the digital pictures with the former analogue pictures with EBRA, as they have different scales. By introducing a calibrating step into the EBRA-program it was possible to do measurements on series of pictures containing digital pictures as well as analogue ones. For displaying the failure of EBRA caused by different radiological techniques we did measurements on a series of consecutive X-rays taken of a model made of acrylic glass and simulating the relevant anatomic structures by screws. The migration of the implant was simulated by shifting it in two directions. Whilst using analogue and digital radiological techniques for taking X-rays, the difference in measurement errors of both techniques was studied. The reliable comparability of X-rays of every format is an absolute necessity for continuing measurements of migration after changing the technique of taking X-rays. The average measurement error of all studied formats of pictures was 0.04 mm (Stdev. 0.11 mm). Though, by using the calibration tool of EBRA migration measurement on X-rays with different formats is possible within the same accuracy. (author)

  8. Total reflection x-ray fluorescence spectrometers for multielemental analysis: status of commercial equipment

    International Nuclear Information System (INIS)

    Ayala Jimenez, R.E.

    2000-01-01

    Multi-elemental analysis by total reflection x-ray fluorescence spectrometry has evolved during two decades. At the present there are commercial equipment available for the chemical analysis in all kind of biological and mineral samples. The electronic industry has also been benefited from the scientific and technological developments in the field of TXRF. The basic components of the spectrometers can be summarized as follow: a) excitation source; b) geometric arrangement (optics) for collimation and monochromatization of the primary radiation; c) x-ray detector; d) hardware and software for operation of the instrument, data acquisition and spectral deconvolution to determine the concentrations of the element present in the sample (quantitative analysis). As optional there are manufacturers offering the conventional 45 degrees geometry for direct excitation of bulky liquid or solid samples. Personal communications of the author and the commercial brochures available at the moment of writing this presentation have allowed to list the following type of components used in the TXRF spectrometers for multi-elemental analysis (the devices used in the electronic industry to analyze silicon wafers are excluded). Excitation: high power x-ray tube, output from 1300 to 2000 watts; metal ceramic low power-ray tube, output up to 50 watts. Different anodes are used but molybdenum, tungsten and copper are frequent. The excitation systems can be customized according to the requirements of the laboratory. Detector: Si-Li semi-conductor liquid nitrogen cooled; silicon solid state thermoelectrically cooled (silicon drift detector SDD and Si-PIN diode). Optics: multilayer monochromator of Si-W or Ni-C; double multilayer monochromator. Electronics: spectroscopy amplifier, analog to digital converter adapted to a PC compatible computer with software in Windows environment for the whole operation of the spectrometer and for qualy/quantitative analysis of samples are standards in the

  9. High resolution projection X-ray microscope equipped with fluorescent X-ray analyzer and its applications

    International Nuclear Information System (INIS)

    Minami, K; Saito, Y; Kai, H; Shirota, K; Yada, K

    2009-01-01

    We have newly developed an open type fine-focus X-ray tube 'TX-510' to realize a spatial resolution of 50nm and to radiate low energy characteristic X-rays for giving high absorption contrast to images of microscopic organisms. The 'TX-510' employs a ZrO/W(100) Schottky emitter and an 'In-Lens Field Emission Gun'. The key points of the improvements are (1) reduced spherical aberration coefficient of magnetic objective lens, (2) easy and accurate focusing, (3) newly designed astigmatism compensator, (4) segmented thin film target for interchanging the target materials by electron beam shift and (5) fluorescent X-ray analysis system.

  10. Quality control for dental X-rays equipment and film developers

    International Nuclear Information System (INIS)

    Pomares C, Martin

    1998-01-01

    Quality control in five dental X-ray equipments, film and film developers was done. It was for evaluating the radiologic practices in the odontologic services too. This work was made based on international standards, the results will be used for future works in quality assurance in dental radiology

  11. 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.

  12. Automated and observer based light field indicator edge evaluation in diagnostic X-ray equipment

    OpenAIRE

    Bottaro, Márcio; Nagy, Balázs Vince; Soares, Fernanda Cristina Salvador; Rosendo, Danilo Cabral

    2017-01-01

    Abstract Introduction To analyze edge detection and optical contrast calculation of light field-indicators used in X-ray via automated- and observer-based methods, and comparison with current standard approaches, which do not give exact definition for light field edge determination. Methods Automated light sensor array was used to measure the penumbra zone of the edge in the standard X-ray equipment, while trained and naïve human observers were asked to mark the light field edge according t...

  13. Study on optical properties of ceramics scintillator for X-ray CT equipment. (Pt. 2)

    International Nuclear Information System (INIS)

    Nakamura, Ryouhei; Tsukuda, Yasuo; Nitanda, Humio

    1993-01-01

    The scintillator elements in X-ray CT equipment of the third generation type require high uniformity of distribution of light output as well as quality response characteristic. Parameters responsible for the distribution of light output were studied using the Monte Carlo method. Although the scattering coefficient was neglected, close agreement was obtained between calculated and experimental results. Calculated results indicated that relative output drop at both ends decreased with increasing optical absorption coefficient and was constant for X-ray absorption factor. (author)

  14. A guide to radiation protection in the use of X-ray optics equipment

    International Nuclear Information System (INIS)

    Bines, W.P.

    1986-01-01

    A booklet has been produced by a Working Group convened by the Health and Safety Executive to provide practical guidance for all who might be involved in work with X-ray optics equipment, such as designers, manufacturers, users, maintenance workers, inspectors, radiation protection advisers and supervisors. The particular radiation protection aspects described include those in connection with enclosure design and inspection, inter locks, tube shields, shutters and cover plates, administrative controls, monitoring and repair and maintenance of equipment. (UK)

  15. X ray spectra and qualities for use in diagnostic radiology and equipment calibration

    International Nuclear Information System (INIS)

    Souza, Karla Cristina de

    1996-12-01

    The goal of this work was the standardization of radiation qualities of diagnostic X ray equipment of the Assay Laboratory of the Institute for Radiation Protection and Dosimetry (IRD) of the National Commission of Nuclear Energy, Brazil. X ray spectra were determined from pulse height distribution measured directly on the primary beam using a high pure planar Ge detector. A program was developed to convert pulse height distribution into radiation spectra in the range from 20 to 150 keV. X ray qualities based on those used by the 'Physikalish-Technish Bundesantalt' (PTB) primary laboratory were implanted in three radiological equipment of the Assay Laboratory. These qualities simulate radiation beams on patients submitted to typical radiological examinations. Besides the spectrometric system, a reference measurement system based on an ionization chamber calibrated in air kerma was used to establish parameters such as kilovoltage, first and second half-value layer, mean energy, effective energy and inherent filtration. Our data have shown that the implantation of these radiation qualities in the Assay Laboratory results on a metrological basis for calibration of dose measurement assemblies and kV-meters, like those used by IRD to evaluate the parameters of X ray equipment around the country. A catalogue of spectral data resulting from this work is a data bank that allows various applications like dose calculation using Monte Carlo simulation techniques. (author)

  16. Evaluation of different X ray equipment and incubators for pediatric radiographic images implementation

    International Nuclear Information System (INIS)

    Carbi, E.D.O.; Souza, R.T.F.; Pina, D.R.

    2009-01-01

    The children frequent/y are exposed to the ionizing radiation and other emotional and physical risks in the attempts repeated to get radiographic images of quality. This study it has as objective to evaluate X ray beam about quality and intensity at three different equipment with single-phase generator of voltage and the absorption factors to 5 different incubators and 3 different cradles in the neonatal UTI of the Clinics Hospital on the Medicine College in Botucatu. The methodology consisted of carrying through measured of half Layer Value and Radiation output for the different X ray equipment with voltage with in between 45 and 100 kVp, applied at the X ray tube. The measures of the absorption factors had been carried through varying the thicknesses of attenuating material (phantom) for the different voltage value with in between 50 and 100kVp. The results had shown the same energy effective for the different X ray equipment and the same absorption factors for the different incubators and evaluated cradles, taking into account, the same thickness of attenuating material and same voltage. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-03-15

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

  18. [The digital reprocessing of under- and overexposed x-ray films with a personal computer].

    Science.gov (United States)

    Fuhrmann, R; Diedrich, P

    1993-02-01

    An image processing work station for digitalizing and interactively manipulating under- and overexposed X-rays was set up by adding modules to an IBM compatible personal computer. Overexposed X-rays can be qualitatively enhanced by means of controlled manipulation of contrast and brightness and by means of the use of various digital filtering techniques. With underexposed X-rays an equalized grey scale can be achieved by means of regulating contrast and brightness. Digital filtering is not required. To assure a high degree of anatomical detail (periodontal ligament) in the digitalized image a maximum pixel of 0.1 mm was defined as a qualitative norm. Since in every digitalization process resolution is diminished, it proved best to select for interactive manipulation out of the total image only the section of interest.

  19. Applying x-ray digital imaging to the verification of cadmium in fuel-storage components

    International Nuclear Information System (INIS)

    Dabbs, R.D.; Cook, D.H.

    1997-01-01

    The High Flux Isotope Reactor utilizes large underwater fuel-storage arrays to stage irradiated fuel before it is shipped from the facility. Cadmium is required as a thermal neutron absorber in these fuel-storage arrays to produce an acceptable margin of nuclear subcriticality during both normal and off-normal operating conditions. Due to incomplete documentation from the time of their fabrication, the presence of cadmium within two stainless-steel parts of fuel-storage arrays must be experimentally verified before they are reused in new fuel-storage arrays. A cadmium-verification program has been developed in association with the Waste Examination and Assay Facility located at the Oak Ridge national Laboratory to nondestructively examine these older shroud assemblies. The program includes the following elements (1) x-ray analog imaging, (2) x-ray digital imaging, (3) prompt-gamma-ray spectroscopy measurements, and (4) neutron-transmission measurements. X-ray digital imaging utilizes an analog-to-digital convertor to record attenuated x-ray intensities observed on a fluorescent detector by a video camera. These x-ray intensities are utilized in expressions for cadmium thickness based upon x-ray attenuation theory

  20. Method and apparatus for analog signal conditioner for high speed, digital x-ray spectrometer

    International Nuclear Information System (INIS)

    Warburton, W.K.; Hubbard, B.

    1999-01-01

    A signal processing system which accepts input from an x-ray detector-preamplifier and produces a signal of reduced dynamic range for subsequent analog-to-digital conversion is disclosed. The system conditions the input signal to reduce the number of bits required in the analog-to-digital converter by removing that part of the input signal which varies only slowly in time and retaining the amplitude of the pulses which carry information about the x-rays absorbed by the detector. The parameters controlling the signal conditioner's operation can be readily supplied in digital form, allowing it to be integrated into a feedback loop as part of a larger digital x-ray spectroscopy system. 13 figs

  1. Present situation and necessity of computer programmed X-ray equipment

    International Nuclear Information System (INIS)

    Shiraishi, Junji; Hatagawa, Masakatsu

    1989-01-01

    In order to take radiographic photos, it is necessary to know a great deal of information. For example, mA, kV, exposure time, screen, grid, phototimer, etc. In this study, we examined 4 widely-used types computer-programmed X-ray equipment. These computer-assisted processes are designed to look at the data and make programmed individual decisions. The purpose is to reduce the differences in radiographic quality and the risk of retaking caused by the differences in experience among technicians. We concluded that none of them has ideal functions but each can be used as a source supply information, if a little remodeling is done, and we confirm that computer-programmed X-ray equipment is, and will continue to go be, necessary. (author)

  2. Clarification of radiation-control regulations for diagnostic x-ray equipment

    International Nuclear Information System (INIS)

    1989-03-01

    The Office of Compliance and Surveillance of the Center for Devices and Radiological Health (CDRH) has received many requests for interpretation of the Federal regulations that relate to diagnostic x-ray equipment. Responses to these requests were originally issued as FDA Compliance Policy Guides, industry-wide letters, and letters to individuals. The document is a compilation of those responses that remain applicable. Guides or opinions that have been withdrawn or are now obsolete because they have been incorporated into the regulations are not included. The document consists of two sections: the General section, which contains information of a general nature; and the Specific section, which contains information specific to particular sections of the Federal Performance Standard for Diagnostic X-ray Equipment (21 CFR 1020.30-32). When the term 'Revised Language' appears in an item heading, it indicates English grammar correction; the term 'Revised' indicates an updated version of the original clarification

  3. The Northern Regional Programme for the acceptance testing of X-ray equipment

    International Nuclear Information System (INIS)

    Faulkner, K.; Harrison, R.M.; Kotre, C.J.; Smith, S.; Davies, M.; Barker, P.

    1989-01-01

    Since 1984 the Regional Medical Physics Department has participated in a regional acceptance testing programme for all X-ray equipment from mobile units to computed tomography scanners. The organizational and radiation physics aspects of the programme are described. Three levels of tests are performed by physicists: the first on installation, the second after 3 months, and the final visit just prior to the end of the manufacturer's warranty. The second test is only performed if any aspect of performance requires rechecking as a result of the first visit. Acceptance test protocols are based on those published by the Institute of Physical Sciences in Medicine. Details of the limiting values for the acceptance test measurements are given. The results of the programme are discussed. In some instances the testing has resulted in modifications to the design and construction of X-ray equipment. Acceptance testing is important in determining a baseline standard of performance against which routine quality assurance may be assessed. (author)

  4. The Northern regional programme for the acceptance testing of X-ray equipment

    International Nuclear Information System (INIS)

    Faulkner, K.; Harrison, R.M.; Kotre, C.J.; Smith, S.; Davies, M.; Barker, P.

    1989-01-01

    Since 1984 the UK Northern Regional Medical Physics Department has participated in a regional acceptance testing programme for all X-ray equipment from mobile units to computed tomography scanners. Organizational and radiation physics aspects of the programme are described. Three levels of tests are performed by physicists: the first on installation, the second after 3 months, the final visit just prior to the end of the manufacturers warranty. The second test is only performed if any aspect of performance requires rechecking as a result of the first. Acceptance test protocols are based on those published by the Institute of Physical Sciences in Medicine. Details limiting values for the acceptance test measurements are given. In some instances testing has resulted in modifications to the design and construction of X-ray equipment. Acceptance testing is important in determining a baseline standard of performance against which routine quality assurance may be assessed. (author)

  5. Specification for high voltage cable plug and socket connections for medical X-ray equipment

    International Nuclear Information System (INIS)

    1980-01-01

    Under the direction of the Light Engineering Standards Committee, a British Standard Specification has been prepared for three-conductor and four-conductor high-voltage cable plug and socket connections for medical X-ray equipment. The standard deals with the essential dimensions to ensure mechanical interchangeability, the recommended dimensions, the wiring connections to contacts of plug and socket and the marking of contacts of plug and socket. (U.K.)

  6. Method and multichannel equipment for chemical analysis by X-ray emission

    International Nuclear Information System (INIS)

    Bacso, J.; Horkay, Gy.; Kalinka, G.; Kertesz, Zs.; Kiss Varga, M.; Lakatos, T.; Mathe, Gy.; Paal, A.; Sulik, B.

    1978-01-01

    In the patent a simple method and an apparatus are described for chemical analysis based on X-ray emission generated by irradiation. The concentrations of pre-selected elements can be determined easily by this method using an equipment containing microprocessor. The number of channels and the elements to be determined can be modified by a simple change in the program. (Sz.J.)

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

    International Nuclear Information System (INIS)

    Hoberg, Bernd; Voigt, Stefan

    2012-01-01

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

  8. A study on enforcement effects of radiation safety control regulations for diagnostic X-ray equipment

    International Nuclear Information System (INIS)

    Sung, Mo IL; Park, Myeong Hwan; Kwon, Duk Moon; Lee, Joon IL

    1999-01-01

    The purposes of this study are to analyze the realities after enforcements of safety control regulations for diagnostic X-ray equipment and to suggest means for an improvement of low radiation safety control. A questionnaire survey for medical radiologic technologists was carried out to determine enforcement effects of the safety control regulations. The results of analysis from the survey are as follows. That is, most of he respondents realized the importance of the radiation safety control system, but about a half of them revealed that regulations were not well observed in accordance with their purposes. Only 43.9 percent of the respondents took an active part in quality control of radiation. And responsibility, sex, age, and knowledge for safety control were important indicators for observations of the regulations. Training for the safety control regulations are needed to ensure safety control and proper usage of diagnostic X-ray equipment. And management of organizations using diagnostic X-ray equipment have to understand and stress the importance of radiation safety control system. (author)

  9. Radiometer evaluation of X-rays equipment in the region of Aracatuba, Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Fernandes, Marco A.R.

    2009-01-01

    This paper presents the basic concepts of radiation protection to guide the health care professionals who use equipment emitting ionizing radiation on the correct handling of the beams of radiation. Radiometric evaluations were conducted in 1665 in X-ray equipment, installed in dental surgeries and clinics, hospitals and radiology services, during the years 1996 to 2003 in the region of Aracatuba. Tests of radiometry are presented as a technical report where the parameters are quantified physical and radiological verifying its compliance with the established by legislation. The distribution of reports by type of unit shows that the vast majority of equipment is of periapical dental x-rays (72%), 25% of equipment is medical equipment for radiology and 3% is dental equipment panoramic model (orthodontic documentation). Among the physical parameters analyzed, the length of the browser was showing more variance compared to the required by law, this fact may also contribute to gaps in the rate of the radiation dose and the size of field in the skin of the patient, the that can easily be resolved simply to replace the piece at the outlet of the head. During the completion of visits to services, it also noted a gap in the training of professionals who operate this equipment emitting radiation, warning of the need for specific training in the area. (author)

  10. Investigation of the performance of digital mammographic X-Ray equipment: Determination of noise equivalent quanta (NEQQC) and detective quantum efficiency (DQEQC) compared with the automated analysis of CDMAM test images with CDCOM and CDIC programs

    International Nuclear Information System (INIS)

    Loos, C.; Buhr, H.; Blendl, C.

    2013-01-01

    Purpose: The purpose of this study was to determine the values for noise equivalent quanta, detective quantum efficiency, modulation transfer function, noise power spectrum, and the values for the parameters for automated CDMAM test phantom analyses required to achieve satisfactory quality of digital mammograms. Materials and Methods: During the course of tests according to PAS 1054 (8 CR and 12 DR systems), test images were made with a test phantom insertion plate containing two lead edges in nearly horizontal and vertical directions. Only original data were processed with a program that was developed at the Cologne University of Applied Sciences (FH-Koeln). All equipment systems complied with the requirements regarding visual recognition of gold-plated mammo detail test objects. CDMAM test images were also evaluated using the CDIC (CUAS) and CDCOM (EUREF) programs. Results: CDMAM test images show comparable values for the parameters, precision, sensitivity and specificity. DR systems require about half the dose used for CR systems for similar results. The NEQ values achieved with the dose used for the CDMAM test images show larger scatter ranges. The MTF of the different equipment system types differ significantly from each other. Conclusion: Visual evaluation of CDMAM test images can be replaced by automated evaluation. Limiting values were determined for each parameter. Automated evaluation of CDMAM test phantom images should be used to determine the physical parameter NEQ QC . This method is much more sensitive to noise and sharpness influences and has a higher validity than diagnostic methods. Automated evaluation objectivizes testing. (orig.)

  11. Network based multi-channel digital flash X-ray imaging system

    International Nuclear Information System (INIS)

    Wang Jingjin; Yuan Jie; Liu Yaqiang; Lin Yong; Song Zheng; Liu Keyin; Zhang Qi; Zheng Futang

    2000-01-01

    A network based multi-channel digital flash X-ray imaging system has been developed. It can be used to acquire and digitize orthogonal flash X-ray images in multi-interval, and to distribute the images on the network. There is no need of films and chemical process, no anxiety of waiting and no trouble of film archiving. This system is useful for testing ballistics, jet, explode, armour-piercing and fast running machines. The system composing and acquired images are presented. The software for object separating, mass calculating, 3D positioning, speed determining and cavity reconstruction are described

  12. Network based multi-channel digital flash X-ray imaging system

    International Nuclear Information System (INIS)

    Wang Jingjin; Yuan Jie; Liu Yaqiang; Lin Yong; Song Zheng; Liu Keyin

    2003-01-01

    A network based multi-channel digital flash X-ray imaging system has been developed. It can be used to acquire and digitize orthogonal flash X-ray images in multi-interval, and to distribute the images on the network. There is no need of films and chemical process, no anxiety of waiting and no trouble of film archiving. This system is useful for testing ballistics, jet, explode, armour-piercing and fast running machines. The system composing and acquired images of terminal ballistics are presented. The software for object separating, profile calculating and 3D cavity reconstruction are described

  13. Wavelet processing and digital interferometric contrast to improve reconstructions from X-ray Gabor holograms.

    Science.gov (United States)

    Aguilar, Juan C; Misawa, Masaki; Matsuda, Kiyofumi; Suzuki, Yoshio; Takeuchi, Akihisa; Yasumoto, Masato

    2018-05-01

    In this work, the application of an undecimated wavelet transformation together with digital interferometric contrast to improve the resulting reconstructions in a digital hard X-ray Gabor holographic microscope is shown. Specifically, the starlet transform is used together with digital Zernike contrast. With this contrast, the results show that only a small set of scales from the hologram are, in effect, useful, and it is possible to enhance the details of the reconstruction.

  14. Radiation protection type testing and licensing of diagnostic X-ray equipment in the GDR

    International Nuclear Information System (INIS)

    Taschner, P.; Poulheim, K.F.; Feldheim, W.

    1987-01-01

    The results of more than 10 years experience in type testing and type licensing of diagnostic X-ray equipment with respect to meeting radiation protection requirements as well as the implications for the conduct of these procedures resulting from the introduction of new radiation protection legislation in 1983 and 1984, are described. At present an updated version of the 'Regulation of 16 December 1977 concerning radiation protection type testing and licensing of sealed radiation sources and equipment emitting ionizing radiation' is being prepared. (author)

  15. [Standard chest x-ray: from film to all digital!].

    Science.gov (United States)

    Ducou Le Pointe, H

    2000-04-01

    Conventional imaging will be totally replaced by digital imaging because of the lower exposure dosage and the clear advantages in terms of image processing, transfer and storage. Reports in the literature have demonstrated that a 2.5 pl/mm spatial resolution is satisfactory to detect a pneumothorax, a parenchymal nodule or a mediastinal mass. For most authors, this resolution is also sufficient to detect an interstitial syndrome. Digitalization by amplification or by particle detectors using wire chambers are not, for the time being, acceptable for interpretation of a simple chest image because of the low spatial resolution. The selenium cylinder is an adapted technology dedicated to chest imaging. Memory display screens can be used to digitalize the entire radiology unit. They are perfectly adapted for bedside imaging. Flat detectors are based on direct or indirect conversion of the X photons into an electrical signal during the clinical evaluation. The early results appear most promising.

  16. A special ionisation chamber for quality control of diagnostic and mammography X ray equipment

    International Nuclear Information System (INIS)

    Costa, A.M.; Caldas, L.V.E.

    2003-01-01

    A quality control program for X ray equipment used for conventional radiography and mammography requires the constancy check of the beam qualities in terms of the half-value layers. In this work, a special double-faced parallel-plate ionisation chamber was developed with inner electrodes of different materials, in a tandem system. Its application will be in quality control programs of diagnostic and mammography X ray equipment for confirmation of half-value layers previously determined by the conventional method. Moreover, the chamber also may be utilised for measurements of air kerma values (and air kerma rates) in X radiation fields used for conventional radiography and mammography. The chamber was studied in relation to the characteristics of saturation, ion collection efficiency, polarity effects, leakage current, and short-term stability. The energy dependence in response of each of the two faces of the chamber was determined over the conventional radiography and mammography X ray ranges (unattenuated beams). The different energy responses of the two faces of the chamber allowed the formation of a tandem system useful for the constancy check of beam qualities. (author)

  17. A special ionisation chamber for quality control of diagnostic and mammography X ray equipment.

    Science.gov (United States)

    Costa, A M; Caldas, L V E

    2003-01-01

    A quality control program for X ray equipment used for conventional radiography and mammography requires the constancy check of the beam qualities in terms of the half-value layers. In this work, a special double-faced parallel-plate ionisation chamber was developed with inner electrodes of different materials, in a tandem system. Its application will be in quality control programs of diagnostic and mammography X ray equipment for confirmation of half-value layers previously determined by the conventional method. Moreover, the chamber also may be utilised for measurements of air kerma values (and air kerma rates) in X radiation fields used for conventional radiography and mammography. The chamber was studied in relation to the characteristics of saturation, ion collection efficiency, polarity effects, leakage current, and short-term stability. The energy dependence in response of each of the two faces of the chamber was determined over the conventional radiography and mammography X ray ranges (unattenuated beams). The different energy response of the two faces of the chamber allowed the formation of a tandem system useful for the constancy check of beam qualities.

  18. A study on the test of efficiency of the diagnostic X-ray equipment according to their rectifications

    International Nuclear Information System (INIS)

    Seon, Jong Ryul

    1997-01-01

    For the efficient management of the diagnostic x-ray equipment, a nation-wide inspection of hospitals was performed by an inspection institute in Taejon in the first half of 1997. Among those hospitals inspected, 28 equipments(machines) which were over 500 mA were randomly selected according to their characteristics : 7 condenser type x-ray equipments, 7 three control phase of full wave rectification of type remote control x-ray equipments, 7 single phase of full wave rectification type for general radiography equipments, and 7 single phase of full wave rectification type of R/F equipments. We obtained the following results by conducting the experiment based on the efficiency of the equipments mentioned above. 1) When te equipments are analyzed, 2 out of 7 single phase of full wave rectification type of general radiography equipments(28.6%), 3 out of 7 single phase of full wave rectification type of R/F equipments(42.9%), 5 out of 7 three phase of full wave rectification type remote of control x-ray equipments(71.4%), and 4 out of 7 condenser type of x-ray equipments(57.1%) showed suitability. It proves the superiority of the three phase of full wave rectification type of remote control x-ray equipments. 2) From the overall analysis, only about 50% of the equipments(suitability of 14 out of 28) maintain the efficient management. Therefore, maintenance management of equipments is more necessary. If the efficiency of the x-ray equipment is uniformly maintained and managed to prevent the breakdown(trouble) beforehand especially through the continuous inspection of tube voltage, tube current, exposure time, and collimator, the financial loss and exposure dose to the patient, as well as the workers engaged in radiation, can be reduced for better medical service

  19. The one million volt X-ray therapy equipment at St Bartholomew's Hospital, 1936-1960

    International Nuclear Information System (INIS)

    Innes, G.S.

    1988-01-01

    St Bartholomew's Hospital in 1934 placed a contract with Messrs Metropolitan Vickers, of Manchester, for an X-ray therapy equipment to operate at 600 kV, 2mA d.c., but with the proviso that every effort would be made to attain an operating condition of 1000 kV, 4mA. The X-ray tube and rectifiers were to be continuously evacuated and demountable. This meant that components such as filaments, anodes and the target could be easily replaced, so providing cheap maintenance and continuous availability of the plant. No specification exists today, but one was assembled from the minutes of the Cancer Committee of the hospital and the contract pricing. A brief outline historical review is also presented, particularly of the personalities involved, and the War years 1939-1945. (author)

  20. Method and apparatus for digitally based high speed x-ray spectrometer

    International Nuclear Information System (INIS)

    Warburton, W.K.; Hubbard, B.

    1997-01-01

    A high speed, digitally based, signal processing system which accepts input data from a detector-preamplifier and produces a spectral analysis of the x-rays illuminating the detector. The system achieves high throughputs at low cost by dividing the required digital processing steps between a ''hardwired'' processor implemented in combinatorial digital logic, which detects the presence of the x-ray signals in the digitized data stream and extracts filtered estimates of their amplitudes, and a programmable digital signal processing computer, which refines the filtered amplitude estimates and bins them to produce the desired spectral analysis. One set of algorithms allow this hybrid system to match the resolution of analog systems while operating at much higher data rates. A second set of algorithms implemented in the processor allow the system to be self calibrating as well. The same processor also handles the interface to an external control computer. 19 figs

  1. A dynamic material discrimination algorithm for dual MV energy X-ray digital radiography

    International Nuclear Information System (INIS)

    Li, Liang; Li, Ruizhe; Zhang, Siyuan; Zhao, Tiao; Chen, Zhiqiang

    2016-01-01

    Dual-energy X-ray radiography has become a well-established technique in medical, industrial, and security applications, because of its material or tissue discrimination capability. The main difficulty of this technique is dealing with the materials overlapping problem. When there are two or more materials along the X-ray beam path, its material discrimination performance will be affected. In order to solve this problem, a new dynamic material discrimination algorithm is proposed for dual-energy X-ray digital radiography, which can also be extended to multi-energy X-ray situations. The algorithm has three steps: α-curve-based pre-classification, decomposition of overlapped materials, and the final material recognition. The key of the algorithm is to establish a dual-energy radiograph database of both pure basis materials and pair combinations of them. After the pre-classification results, original dual-energy projections of overlapped materials can be dynamically decomposed into two sets of dual-energy radiographs of each pure material by the algorithm. Thus, more accurate discrimination results can be provided even with the existence of the overlapping problem. Both numerical and experimental results that prove the validity and effectiveness of the algorithm are presented. - Highlights: • A material discrimination algorithm for dual MV energy X-ray digital radiography is proposed. • To solve the materials overlapping problem of the current dual energy algorithm. • The experimental results with the 4/7 MV container inspection system are shown.

  2. Preliminary evaluation of operational parameters in fixed x-ray diagnostics equipment

    International Nuclear Information System (INIS)

    Bacelar, Alexandre; Oliveira, Sandro Soletti de; Streck, Elaine E.; Furtado, Alvaro Porto Alegre; Pinto, Ana Lucia Acosta

    1998-01-01

    In this work they were appraised 22 fixed X-ray diagnostic equipment belonging to three great medical institutions in Porto Alegre - RS, Brazil, with the purpose of demonstrating the importance of the implementation of a Quality Warranty program, advised by a health physicist, in the performance of these equipment. For so some data of alignment and collimation of the beam, peak tube voltage, tube current, transportable charge and exposition time were collected. The results of the tests showed that in only one of the institutions all the equipment remained in operationally acceptable conditions, with relative percent errors below 10%, concerning to the analyzed parameters. This study also showed that the performance of the equipment of the three analyzed institutions is a direct reflex of the maintenance of a Quality Warranty Program, advised by a qualified professional. (author)

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  4. The use of the Statscan digital X-ray unit in paediatric polytrauma

    Energy Technology Data Exchange (ETDEWEB)

    Pitcher, Richard D. [University of Cape Town, Division of Paediatric Radiology, Red Cross War Memorial Children' s Hospital, School of Child and Adolescent Health, Cape Town (South Africa); Wilde, Jim C.H. [University of Cape Town, Division of Paediatric Surgery, Red Cross War Memorial Children' s Hospital, School of Child and Adolescent Health, Cape Town (South Africa); University of Amsterdam, Paediatric Surgical Centre of Amsterdam, Emma Children' s Hospital, Academic Medical Centre, Amsterdam (Netherlands); Douglas, Tania S. [University of Cape Town, MRC/UCT Medical Imaging Research Unit, Department of Human Biology, Cape Town (South Africa); As, Arjan Bastiaan van [University of Cape Town, Division of Paediatric Surgery, Red Cross War Memorial Children' s Hospital, School of Child and Adolescent Health, Cape Town (South Africa)

    2009-05-15

    We present a 3-year review of clinical paediatric experience with the statscan (Lodox Systems, Johannesburg, South Africa), a low-dose, digital, whole-body, slit-scanning X-ray machine. While focusing on the role of the unit in paediatric polytrauma, insight into its applications in other paediatric settings is provided. (orig.)

  5. The use of the Statscan digital X-ray unit in paediatric polytrauma

    International Nuclear Information System (INIS)

    Pitcher, Richard D.; Wilde, Jim C.H.; Douglas, Tania S.; As, Arjan Bastiaan van

    2009-01-01

    We present a 3-year review of clinical paediatric experience with the statscan (Lodox Systems, Johannesburg, South Africa), a low-dose, digital, whole-body, slit-scanning X-ray machine. While focusing on the role of the unit in paediatric polytrauma, insight into its applications in other paediatric settings is provided. (orig.)

  6. The implementation of modern digital technology in x-ray medical diagnosis in Republic of Moldova - a stringent necessity

    International Nuclear Information System (INIS)

    Rosca, Andrei

    2011-01-01

    The study includes analyses of current technical state of radiodiagnostic equipment from the Public Medico-Sanitary Institution of Ministry of Health of Republic of Moldova (IMSP MS RM). The traditional radiodiagnostic apparatuses were morally and physically outrun at 96,6% (in regional MSPI - 93,5%), inclusive the dental one - 92,0% (in raional MSPI - 97,2%), X-Ray exam -100%, mobile - 84,1% etc. The exploitation of the traditional radiodiagnostic apparatuses with high degree of physical and moral wear essentially diminished the quality of profile investigation, creates premises for diagnostic error perpetrating, increase the collective ionizing irradiation of population etc. In recent years the subvention of MSPI HM RM with digital radiodiagnostic equipment was started. This process is very hard unfold because of grave socio-economic crises in Republic of Moldova. Despite these obstacles the subvention of MSPI HM RM with digital equipment represents a stringent necessity and a time request.

  7. Is there an isotope on your books? Advice to receivers and liquidators on dealing with X-ray sources and X-ray equipment

    International Nuclear Information System (INIS)

    Colgan, Tony.

    1987-01-01

    The paper outlines advice to receivers and liquidators on dealing with radioactive sources and X-ray equipment. When companies go into liquidation it is important that the accountants handling the winding up are aware of the law and their responsibilities if radioactive materials are present. Guidelines are presented here which may help indicate to the accountant the likely presence of radioactive materials and the procedure which should be followed when arranging sale or disposal of these items

  8. Selective photon counter for digital x-ray mammography tomosynthesis

    Science.gov (United States)

    Goldan, Amir H.; Karim, Karim S.; Rowlands, J. A.

    2006-03-01

    Photon counting is an emerging detection technique that is promising for mammography tomosynthesis imagers. In photon counting systems, the value of each image pixel is equal to the number of photons that interact with the detector. In this research, we introduce the design and implementation of a low noise, novel selective photon counting pixel for digital mammography tomosynthesis in crystalline silicon CMOS (complementary metal oxide semiconductor) 0.18 micron technology. The design comprises of a low noise charge amplifier (CA), two low offset voltage comparators, a decision-making unit (DMU), a mode selector, and a pseudo-random counter. Theoretical calculations and simulation results of linearity, gain, and noise of the photon counting pixel are presented.

  9. An appraisal of current regulations and recommendations in relation to proposals for the use of X-ray optics equipment

    International Nuclear Information System (INIS)

    Weatherley, E.G.

    1984-01-01

    Current regulatory requirements for the use of x-ray optics equipment in factories are compared with the 19-year-old Guidance Notes for their use in research and teaching establishments. The difficulties in drafting new legislation to cater for both areas of use are discussed and the proposed regulations and approved code of practice having a direct bearing on x-ray optics equipment are reviewed. Comment is made concerning the proposed Health and Safety Executive document, ''Radiation Safety in the use of X-ray Optics Equipment, which will give practical advice and guidance on cost effective methods of achieving the regulatory objectives. The costs involved are unlikely to be significant for the majority of users and implementation of the proposed legislation should not restrict the use of x-ray optics equipment. (author)

  10. Calibration voltage test of non invasive meter for radiodiagnostic on equipment of constant potential X-ray

    International Nuclear Information System (INIS)

    Ramos, Manoel M.O.; Peixoto, J. Guilherme P.; Pereira, Marco A.G.S.

    2009-01-01

    This work evaluates the utilization of the non invasive voltage meter PTW Diavolt Universal in industrial X ray equipment of constant potential. With the performed measurements, the conclusion is that conclusion is possible, once his use limits are identified

  11. Digital signal processors for cryogenic high-resolution x-ray detector readout

    International Nuclear Information System (INIS)

    Friedrich, Stephan; Drury, Owen B.; Bechstein, Sylke; Hennig, Wolfgang; Momayezi, Michael

    2003-01-01

    We are developing fast digital signal processors (DSPs) to read out superconducting high-resolution X-ray detectors with on-line pulse processing. For superconducting tunnel junction (STJ) detector read-out, the DSPs offer online filtering, rise time discrimination and pile-up rejection. Compared to analog pulse processing, DSP readout somewhat degrades the detector resolution, but improves the spectral purity of the detector response. We discuss DSP performance with our 9-channel STJ array for synchrotron-based high-resolution X-ray spectroscopy. (author)

  12. Three Dimensional Digital Sieving of Asphalt Mixture Based on X-ray Computed Tomography

    OpenAIRE

    Chichun Hu; Jiexian Ma; M. Emin Kutay

    2017-01-01

    In order to perform three-dimensional digital sieving based on X-ray computed tomography images, the definition of digital sieve size (DSS) was proposed, which was defined as the minimum length of the minimum bounding squares of all possible orthographic projections of an aggregate. The corresponding program was developed to reconstruct aggregate structure and to obtain DSS. Laboratory experiments consisting of epoxy-filled aggregate specimens were conducted to investigate the difference betw...

  13. General guidelines about performance specifications for purchasing equipment for x-ray diagnostics, with comments

    International Nuclear Information System (INIS)

    1995-12-01

    These general guidelines are intended to be used as a basis for what requirements are reasonable from a radiation protection point of view and should be part of the contract in connection with the purchase of equipment for x-ray diagnostics. Technical performance requirements are addressed as well as items like documentation, instructions for use and education and training. The guidelines are also useful for the design of quality assurance programs. In the comments in addition to these guidelines legal aspects are noted, including a list of relevant laws, regulations and directives. Standards, both national and international, within the field are referred to with a short description of their content. 40 refs

  14. Equipment to fabricate a masking layer on a carrier by means of soft X-ray

    International Nuclear Information System (INIS)

    Smith, H.I.; Spears, D.L.; Stern, E.

    1978-01-01

    The equipment is to improve the pattern multiplication technique for producing e.g. microminiature current rings. It uses soft X-radiation (2 to 20 A) from an Al anticathode. The mask consists of a Si layer penetrable by X-rays and an opaque pattern layer of Au to limit the mask pattern. Polymethyl metacrylate is suitable as sensitive layer for X-radiation, which is coated on a carrier. The sensitive layer can be prepared from methyl isobutyl ketone and isopropyl alcohol. (ORU/ORU) [de

  15. General guidelines about performance specifications for purchasing equipment for x-ray diagnostics, with comments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    These general guidelines are intended to be used as a basis for what requirements are reasonable from a radiation protection point of view and should be part of the contract in connection with the purchase of equipment for x-ray diagnostics. Technical performance requirements are addressed as well as items like documentation, instructions for use and education and training. The guidelines are also useful for the design of quality assurance programs. In the comments in addition to these guidelines legal aspects are noted, including a list of relevant laws, regulations and directives. Standards, both national and international, within the field are referred to with a short description of their content. 40 refs.

  16. X-ray image intensifier/television systems for digital skeletal radiography

    International Nuclear Information System (INIS)

    Rowlands, J.A.; Hynes, D.M.; Edmonds, E.W.; Porter, A.J.; Toth, B.J.

    1987-01-01

    The imaging criteria for skeletal radiography (high resolution and low noise) relevant to the use of x-ray image intensifier/TV digital systems are discussed. It is shown from the modulation transfer function (MTF), noise, and phantom evaluations that conventional x-ray image intensifiers in conjunction with a 1,000-line Plumbicon or Saticon TV camera are in most respects suitable for skeletal radiography. The optimum focal spot size depends on a trade-off with motion blurring through the x-ray exposure time and so is a function of the clinical problem. Since the skeletal system is readily immobilized, a 0.3-mm focal spot size is nearly optimum

  17. Automatic analysis of quality of images from X-ray digital flat detectors

    International Nuclear Information System (INIS)

    Le Meur, Y.

    2009-04-01

    Since last decade, medical imaging has grown up with the development of new digital imaging techniques. In the field of X-ray radiography, new detectors replace progressively older techniques, based on film or x-ray intensifiers. These digital detectors offer a higher sensibility and reduced overall dimensions. This work has been prepared with Trixell, the world leading company in flat detectors for medical radiography. It deals with quality control on digital images stemming from these detectors. High quality standards of medical imaging impose a close analysis of the defects that can appear on the images. This work describes a complete process for quality analysis of such images. A particular focus is given on the detection task of the defects, thanks to methods well adapted to our context of spatially correlated defects in noise background. (author)

  18. An application specific integrated circuit and data acquisition system for digital X-ray imaging

    International Nuclear Information System (INIS)

    Beuville, E.; Cederstroem, B.; Danielsson, M.; Luo, L.; Nygren, D.; Oltman, E.; Vestlund, J.

    1998-01-01

    We have developed an application specific integrated circuit (ASIC) and data acquisition system for digital X-ray imaging. The chip consists of 16 parallel channels, each containing preamplifier, shaper, comparator and a 16 bit counter. We have demonstrated noiseless single-photon counting over a threshold of 7.2 keV using Silicon detectors and are presently capable of maximum counting rates of 2 MHz per channel. The ASIC is controlled by a personal computer through a commercial PCI card, which is also used for data acquisition. The content of the 16 bit counters are loaded into a shift register and transferred to the PC at any time at a rate of 20 MHz. The system is non-complicated, low cost and high performance and is optimised for digital X-ray imaging applications. (orig.)

  19. An application specific integrated circuit and data acquisition system for digital X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Beuville, E.; Cederstroem, B.; Danielsson, M.; Luo, L.; Nygren, D.; Oltman, E.; Vestlund, J. [Lawrence Berkeley National Lab., CA (United States)

    1998-04-01

    We have developed an application specific integrated circuit (ASIC) and data acquisition system for digital X-ray imaging. The chip consists of 16 parallel channels, each containing preamplifier, shaper, comparator and a 16 bit counter. We have demonstrated noiseless single-photon counting over a threshold of 7.2 keV using Silicon detectors and are presently capable of maximum counting rates of 2 MHz per channel. The ASIC is controlled by a personal computer through a commercial PCI card, which is also used for data acquisition. The content of the 16 bit counters are loaded into a shift register and transferred to the PC at any time at a rate of 20 MHz. The system is non-complicated, low cost and high performance and is optimised for digital X-ray imaging applications. (orig.). 11 refs.

  20. High-energy x-ray CT and its application for digital engineering

    International Nuclear Information System (INIS)

    Kamimura, H.; Sadaoka, N.

    2005-01-01

    A high-energy x-ray computed tomography system and x-ray CT data handling software have been developed for digital engineering; internal dimension measurement, density analysis, actual and designed shape comparison, STL file generation, and support for reverse engineering and rapid prototyping. The system is designed to collect accurate images in short scanning time (10 s per section) using a MeV-energy electron linear accelerator and highly sensitive semiconductor detectors in order to scan large objects made of aluminum and/or iron. An excellent environment in digital engineering is provided by the software products; 'StereoCooker' for 3D bitmap CAD (rendering, feature extraction, dimensional measurement, and shape comparison, etc.), 'FeatureMaker' for translating bitmap CT data to CAD data including feature information, and 'Wingware' for realizing an Windows PC cluster system 'WINGluster' to apply CT data analysis. (author)

  1. High resolution stationary digital breast tomosynthesis using distributed carbon nanotube x-ray source array.

    Science.gov (United States)

    Qian, Xin; Tucker, Andrew; Gidcumb, Emily; Shan, Jing; Yang, Guang; Calderon-Colon, Xiomara; Sultana, Shabana; Lu, Jianping; Zhou, Otto; Spronk, Derrek; Sprenger, Frank; Zhang, Yiheng; Kennedy, Don; Farbizio, Tom; Jing, Zhenxue

    2012-04-01

    The purpose of this study is to investigate the feasibility of increasing the system spatial resolution and scanning speed of Hologic Selenia Dimensions digital breast tomosynthesis (DBT) scanner by replacing the rotating mammography x-ray tube with a specially designed carbon nanotube (CNT) x-ray source array, which generates all the projection images needed for tomosynthesis reconstruction by electronically activating individual x-ray sources without any mechanical motion. The stationary digital breast tomosynthesis (s-DBT) design aims to (i) increase the system spatial resolution by eliminating image blurring due to x-ray tube motion and (ii) reduce the scanning time. Low spatial resolution and long scanning time are the two main technical limitations of current DBT technology. A CNT x-ray source array was designed and evaluated against a set of targeted system performance parameters. Simulations were performed to determine the maximum anode heat load at the desired focal spot size and to design the electron focusing optics. Field emission current from CNT cathode was measured for an extended period of time to determine the stable life time of CNT cathode for an expected clinical operation scenario. The source array was manufactured, tested, and integrated with a Selenia scanner. An electronic control unit was developed to interface the source array with the detection system and to scan and regulate x-ray beams. The performance of the s-DBT system was evaluated using physical phantoms. The spatially distributed CNT x-ray source array comprised 31 individually addressable x-ray sources covering a 30 angular span with 1 pitch and an isotropic focal spot size of 0.6 mm at full width at half-maximum. Stable operation at 28 kV(peak) anode voltage and 38 mA tube current was demonstrated with extended lifetime and good source-to-source consistency. For the standard imaging protocol of 15 views over 14, 100 mAs dose, and 2 × 2 detector binning, the projection

  2. Depth of quantization in signals of the digital X-ray television

    International Nuclear Information System (INIS)

    Beuthan, J.

    1989-01-01

    The technological realization of image acquisition and processing in digital X-ray television in methodical dependence on the image-forming purpose places particular requirements in signal quantization. By evaluation of experimental results with simultaneous modification of a special calculation method an optimum quantization stage is ascertained with method-relevant quantization characteristic. In addition to consideration made so far in this field a self-contained solution is presented with inclusion of vision physiology and information gain. (author)

  3. Radiation protection and the safe use of X-ray equipment: Laws, regulations and responsibilities

    Directory of Open Access Journals (Sweden)

    Charles Petrus Herbst

    2012-06-01

    Full Text Available Lately, South Africa’s regulatory framework for electromagnetic medical devices has come under considerable pressure. In this article the legislative framework and regulatory infrastructure are scrutinized, by looking at how the legislature has given form to protective measures against ionizing radiation. Although the Hazardous Substances Act provides for effective protection against radiation, poor administration led to insufficient staffing levels, uncertainty about Regulations and licensing conditions and therefore undermines a sound radiation protection infrastructure. The legal basis of enforcing licensing conditions through a website without proper consultation with interested and affected parties is questionable and ineffective in controlling radiation levels. Effective and legal radiation control is possible by activating the National Advisory Committee on Electronic Products provided for in Regulation R326 published in 1979, but never implemented. The possible impact of annual quality assurance tests currently enforced through licensing conditions on the radiation dose of the population is not cost effective as new training and accreditation structures had to be created. The fact that generally more than 80% of overexposures are caused by human error is a clear indication that training of the daily users of X-ray equipment should be emphasized and not the training and accreditation of the technicians responsible for a single quality assurance test per year. Constructive engagement with the professional bodies involved in the medical use of X-rays through a National Advisory Committee on Electronic Products may be a cost effective solution for lowering radiation dose to the population.

  4. Stationary intraoral digital tomosynthesis using a carbon nanotube X-ray source array.

    Science.gov (United States)

    Shan, J; Tucker, A W; Gaalaas, L R; Wu, G; Platin, E; Mol, A; Lu, J; Zhou, O

    2015-01-01

    Intraoral dental tomosynthesis and closely related tuned-aperture CT (TACT) are low-dose three-dimensional (3D) imaging modalities that have shown improved detection of multiple dental diseases. Clinical interest in implementing these technologies waned owing to their time-consuming nature. Recently developed carbon nanotube (CNT) X-ray sources allow rapid multi-image acquisition without mechanical motion, making tomosynthesis a clinically viable technique. The objective of this investigation was to evaluate the feasibility of and produce high-quality images from a digital tomosynthesis system employing CNT X-ray technology. A test-bed stationary intraoral tomosynthesis unit was constructed using a CNT X-ray source array and a digital intraoral sensor. The source-to-image distance was modified to make the system comparable in image resolution to current two-dimensional intraoral radiography imaging systems. Anthropomorphic phantoms containing teeth with simulated and real caries lesions were imaged using a dose comparable to D-speed film dose with a rectangular collimation. Images were reconstructed and analysed. Tomosynthesis images of the phantom and teeth specimen demonstrated perceived image quality equivalent or superior to standard digital images with the added benefit of 3D information. The ability to "scroll" through slices in a buccal-lingual direction significantly improved visualization of anatomical details. In addition, the subjective visibility of dental caries was increased. Feasibility of the stationary intraoral tomosynthesis is demonstrated. The results show clinical promise and suitability for more robust observer and clinical studies.

  5. X-ray light valve (XLV): a novel detectors' technology for digital mammography

    Science.gov (United States)

    Marcovici, Sorin; Sukhovatkin, Vlad; Oakham, Peter

    2014-03-01

    A novel method, based on X-ray Light Valve (XLV) technology, is proposed for making good image quality yet inexpensive flat panel detectors for digital mammography. The digital mammography markets, particularly in the developing countries, demand quality machines at substantially lower prices than the ones available today. Continuous pressure is applied on x-ray detectors' manufacturers to reduce the flat panel detectors' prices. XLV presents a unique opportunity to achieve the needed price - performance characteristics for direct conversion, x-ray detectors. The XLV based detectors combine the proven, superior, spatial resolution of a-Se with the simplicity and low cost of liquid crystals and optical scanning. The x-ray quanta absorbed by a 200 μm a-Se produce electron - hole pairs that move under an electric field to the top and bottom of a-Se layer. This 2D charge distribution creates at the interface with the liquid crystals a continuous (analog) charge image corresponding to the impinging radiation's information. Under the influence of local electrical charges next to them, the liquid crystals twist proportionally to the charges and vary their light reflectivity. A scanning light source illuminates the liquid crystals while an associated, pixilated photo-detector, having a 42 μm pixel size, captures the light reflected by the liquid crystals and converts it in16 bit words that are transmitted to the machine for image processing and display. The paper will describe a novel XLV, 25 cm x 30 cm, flat panel detector structure and its underlying physics as well as its preliminary performance measured on several engineering prototypes. In particular, the paper will present the results of measuring XLV detectors' DQE, MTF, dynamic range, low contrast resolution and dynamic behavior. Finally, the paper will introduce the new, low cost, XLV detector based, digital mammography machine under development at XLV Diagnostics Inc.

  6. Optimization of tungsten x-ray spectra for digital mammography: a comparison of model to experiment

    Science.gov (United States)

    Andre, Michael P.; Spivey, Brett A.

    1997-05-01

    Tungsten (W) target x-rays tubes are being studied for use in digital mammography to improve x-ray flux, reduce noise and increase tube heat capacity. A parametric model was developed for digital mammography to evaluate optimization of x-ray spectra for a particular sensor. The model computes spectra and mean glandular doses (MGD) for combinations of W target, beam filters, kVp, breast type and thickness. Two figures of merit were defined: (signal/noise)2/MGD and spectral quantum efficiency; these were computed as a means to approach optimization of object contrast. The model is derived from a combination of classic equations, XCOM from NBS, and published data. X-ray spectra were calculated and measured for filters of Al, Sn, Rh, Mo and Ag on a Eureka tube. (Signal/noise)2/MGD was measured for a filtered W target tube and a digital camera employing CsI scintillator optically coupled to a CCD for which the detective quantum efficiency (DQE) was known. A 3-mm thick acrylic disk was imaged on thickness of 3-8 cm of acrylic and the results were compared to the predictions of the model. The relative error between predicted and measured spectra was +/- 2 percent from 24 to 34 kVp. Calculated MGD as a function of breast thickness, half-value layer and beam filter compares very well to published data. Best performance was found for the following combinations: Mo filter with 30 mm breast, Ag filter with 45 mm, Sn filter for 60 mm, and Al filter for 75 mm thick breast. The parametric model agrees well with measurement and provides a means to explore optimum combinations of kVp and beam filter. For a particular detector, this data may be used with the DQE to estimate total system signal-to-noise ratio for a particular imaging task.

  7. Regulations No. 59 of 20 February 1978 on X-ray skin therapy equipment up to 50 kV

    International Nuclear Information System (INIS)

    1978-01-01

    These regulations lay down the provisions to be complied with for the protection of medical staff and patients when using X-ray equipment for skin therapy. The operators of such equipment must comply with the technical guidelines contained in the regulations and provision is made for annual inspections to ensure that the devices meet the necessary safety standards. (NEA) [fr

  8. Scanning-beam digital x-ray (SBDX) technology for interventional and diagnostic cardiac angiography

    International Nuclear Information System (INIS)

    Speidel, Michael A.; Wilfley, Brian P.; Star-Lack, Josh M.; Heanue, Joseph A.; Van Lysel, Michael S.

    2006-01-01

    The scanning-beam digital x-ray (SBDX) system is designed for x-ray dose reduction in cardiac angiographic applications. Scatter reduction, efficient detection of primary x-rays, and an inverse beam geometry are the main components of the entrance dose reduction strategy. This paper reports the construction of an SBDX prototype, image reconstruction techniques, and measurements of spatial resolution and x-ray output. The x-ray source has a focal spot that is electronically scanned across a large-area transmission target. A multihole collimator beyond the target defines a series of x-ray beams directed at a distant small-area detector array. The prototype has a 23 cmx23 cm target, 100x100 focal spot positions, and a 5 cmx5 cm CdTe detector positioned 150 cm from the target. With this nonmechanical method of beam scanning, patient images with low detected scatter are generated at up to 30 frame/s. SBDX data acquisition is tomosynthetic. The prototype simultaneously reconstructs 16 planes spaced throughout the cardiac volume using shift-and-add backprojection. Image frames analogous to conventional projection images are generated with a multiplane compositing algorithm. Single-plane versus multiplane reconstruction of contrast-filled coronary arteries is demonstrated with images of the porcine heart. Phantom and porcine imaging studies show multiplane reconstruction is practicable under clinically realistic levels of patient attenuation and cardiac motion. The modulation transfer function for an in-plane slit at mechanical isocenter measured 0.41-0.56 at 1 cycle/mm, depending on the detector element to image pixel interpolation technique. Modeling indicates that desired gains in spatial resolution are achievable by halving the detector element width. The x-ray exposure rate 15 cm below isocenter, without table or patient in the beam, measured 11.5 R/min at 120 kVp, 24.3 kWp and 3.42 R/min at 70 kVp, 14.2 kWp

  9. Methods for improvement of some parameters of medical X-ray diagnostic equipment. Basic faults in selection of appropriate new or used units

    International Nuclear Information System (INIS)

    Tonev, M.; Danev, N.; Constantinov, B.

    2004-01-01

    An analysis is made of the factors determining the quality and performance of the main types of medical equipment: conventional radiographic and fluoroscopic X-ray unit; X-ray computer tomograph (CT); angiographic, mammographic, densitometric and dental X-ray equipment; magnetic resonance MRI. The aim is to give certain directions for the method one should adopt on choosing and purchasing X-ray equipment. Also one should take into consideration the new Health law and the Regulation for radiation protection of persons undergoing medical examination or treatment. The problems can be solved with the close cooperation between radiologists, medical physicists and x-ray engineers

  10. Standard practice for digital imaging and communication in nondestructive evaluation (DICONDE) for X-ray computed tomography (CT) test methods

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

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

  11. Long-term in-vitro precision of direct digital X-ray radiogrammetry

    International Nuclear Information System (INIS)

    Dhainaut, Alvilde; Hoff, Mari; Kaelvesten, Johan; Lydersen, Stian; Forslind, Kristina; Haugeberg, Glenn

    2011-01-01

    Digital X-ray radiogrammetry (DXR) calculates peripheral bone mineral density (BMD) from hand radiographs. The short-term precision for direct DXR has been reported to be highly satisfactory. However, long-term precision for this method has not been examined. Thus, the aim of this study was to examine the long-term in-vitro precision for the new direct digital version of DXR. The in-vitro precision for direct DXR was tested with cadaver phantoms on four different X-ray systems at baseline, 3 months, 6 months, and in one machine also at 12 months. At each time point, 31 measurements were performed. The in-vitro longitudinal precision for the four radiographic systems ranged from 0.22 to 0.43% expressed as coefficient of variation (CV%). The smallest detectable difference (SDD) ranged from 0.0034 to 0.0054 g/cm 2 . The in vitro long-term precision for direct DXR was comparable to the previous reported short-term in-vitro precision for all tested X-ray systems. These data show that DXR is a stable method for detecting small changes in bone density during 6-12 months of follow-up. (orig.)

  12. Performance of low-cost X-ray area detectors with consumer digital cameras

    International Nuclear Information System (INIS)

    Panna, A.; Gomella, A.A.; Harmon, K.J.; Chen, P.; Miao, H.; Bennett, E.E.; Wen, H.

    2015-01-01

    We constructed X-ray detectors using consumer-grade digital cameras coupled to commercial X-ray phosphors. Several detector configurations were tested against the Varian PaxScan 3024M (Varian 3024M) digital flat panel detector. These include consumer cameras (Nikon D800, Nikon D700, and Nikon D3X) coupled to a green emission phosphor in a back-lit, normal incidence geometry, and in a front-lit, oblique incidence geometry. We used the photon transfer method to evaluate detector sensitivity and dark noise, and the edge test method to evaluate their spatial resolution. The essential specifications provided by our evaluation include discrete charge events captured per mm 2 per unit exposure surface dose, dark noise in equivalents of charge events per pixel, and spatial resolution in terms of the full width at half maximum (FWHM) of the detector's line spread function (LSF). Measurements were performed using a tungsten anode X-ray tube at 50 kVp. The results show that the home-built detectors provide better sensitivity and lower noise than the commercial flat panel detector, and some have better spatial resolution. The trade-off is substantially smaller imaging areas. Given their much lower costs, these home-built detectors are attractive options for prototype development of low-dose imaging applications

  13. X-ray diagnostics in non-specialized conditions

    International Nuclear Information System (INIS)

    Vasil’yev, A Y; Lyubimenko, V A; Potrakhov, Y N; Potrakhov, N N; Bessonov, V B; Klonov, V V; Larionov, I A; Gryaznov, A Y; Zhamova, K K

    2017-01-01

    The results of research in the development of X-ray diagnostic equipment in non-specialized conditions are described. The design of the first domestic digital X-ray diagnostic complex for neonatology in portable design is presented. Examples of X-ray images obtained “at home” from a patient are given. (paper)

  14. Comparative survey of site and personnel monitoring characteristics for operation of various types of diagnostic-X ray equipment

    International Nuclear Information System (INIS)

    Lyarskij, P.P.; Zol'nikova, N.I.

    1977-01-01

    Diagnostic X-ray machines in present use at medical facilities differ in design and operating parameters, this diversity producing, in turn, a variety of local radiological situations and levels of personnel exposure. Based on radiological safety characterization of working conditions, the authors present a breakdown of contemporary diagnostic X-ray equipment types, based on detailed examination of each group in terms of their associated site monitoring and dosimetry patterns. The paper reports data on personnel exposure levels not only as a function of equipment design and operating characteristics but also according to types of occupational activities for particular medical personnel groups (radiologists, surgeons, anesthesiologists, etc.). Included are health physics data for domestic and foreign X-ray equipment, levels of local and absorbed doses for radiologists, cardiovascular surgeons, neurosurgeons, urologists, traumatologists, anesthesiologists, etc. Measures are recommended for optimizing their activities from the standpoint of radiation safety. (author)

  15. Effective x-ray attenuation measurements with full field digital mammography

    International Nuclear Information System (INIS)

    Heine, John J.; Behera, Madhusmita

    2006-01-01

    This work shows that effective x-ray attenuation coefficients may be estimated by applying Beer's Law to phantom image data acquired with the General Electric Senographe 2000D full field digital mammography system. Theoretical developments are provided indicating that an approximate form of the Beer's relation holds for polychromatic x-ray beams. The theoretical values were compared with experimentally determined measured values, which were estimated at various detector locations. The measured effective attenuation coefficients are in agreement with those estimated with theoretical developments and numerical integration. The work shows that the measured quantities show little spatial variation. The main ideas are demonstrated with polymethylmethacrylate and breast tissue equivalent phantom imaging experiments. The work suggests that the effective attenuation coefficients may be used as known values for radiometric standardization applications that compensate for the image acquisition influences. The work indicates that it is possible to make quantitative attenuation coefficient measurements from a system designed for clinical purposes

  16. Mechanical system design in the engineering design of digital x-ray

    International Nuclear Information System (INIS)

    Muhammad Awwaluddin; I Putu Susila; Edy Purwanta; Abdul Jalil; Ahmad H

    2014-01-01

    Has been designed a mechanical system design to hold and moving the x-ray tube, detector films, and a place the holder control box. The design was conducted on the frame foundation, frame columns and frame arms in order to operate the device as well SS304 hollow measuring 40 x 60 x mm with thickness of 2 mm long 4.1 m, size 100 x 100 mm and 2 mm thick along the 2 m, and the size of 40 x 80 mm thickness 2 mm long 1.8 m is needed to reactive the design the linear guide way models HGW20HB 3 m. With the proposed design, the operation of the digital x-rays can be completed as well. (author)

  17. Digital in-line X-ray holography with zone plates.

    Science.gov (United States)

    Heine, R; Gorniak, T; Nisius, T; Christophis, C; Pettitt, M E; Staier, F; Wilhein, T; Rehbein, S; Grunze, M; Rosenhahn, A

    2011-07-01

    Single pulse imaging with radiation provided by free-electron laser sources is a promising approach towards X-ray microscopy, which is expected to provide high resolution images of biological samples unaffected by radiation damage. One fully coherent imaging technique for this purpose is digital in-line holography. Key to its successful application is the creation of X-ray point sources with high photon flux. In this study we applied zone plates to create such point sources with synchrotron radiation provided by the storage ring BESSY II. The obtained, divergent light cone is applied to holographic microscopy of biological objects such as critical point dried Navicula perminuta diatoms and human cells using photons with an energy of 250 eV. Compared to conventional experiments employing pinholes, exposure times are reduced by two orders of magnitude. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Quality assessment of the digitalization process of analog x-ray images

    International Nuclear Information System (INIS)

    Georgieva, D.

    2014-01-01

    Computer-assisted diagnosis enabled doctors for a second point-of-view on the test results. This improves the diseases' early detection and significantly reduces the chance of errors. These methods very nicely complemented the possibilities of digital medical imaging apparatus, but in analog images their applicability and results entirely depend on the quality of analog images digitalisation. Today many standards and remarks for good practices discuss the digital apparatus image quality but the digitalisation process of analog medical images is not a part of them. Medical imaging apparatus have become digital, but within an entirely digital medical environment is necessary for their ability to blend with the old analog medical imaging carriers. The life of patients doesn't start with the beginning of digital era and for the aim of tracking diseases it is necessary to use the new digital images as well as older analog ones. For the generation of 40-50 years a large archive of images is piled up, which should be accounted of in the diagnosis process. This article is the author's study of the digitalized image quality problem. It offers a new approach to the x-ray image digitalisation - getting the HDR-image by optical sensor. After the HDR-image generation method offers to be used a digital signal processing to improve the quality of the final 16 bit gray scale medical image. The new method for medical image enhancement is proposed - it improves the image contrast, it increases or preserves the dynamic range and it doesn't lead to the loss of small low contrast structures in the image. Key words: Quality of Digital X-Rays Images

  19. Results of evaluation of quality control measurement instrument of x-ray diagnostic equipment by non-invasive method

    International Nuclear Information System (INIS)

    Laan, Flavio T. van der; Elbern, Alvin W.

    1996-01-01

    This work shows the results of the tests realized on Santa Rita Hospital (Porto Alegre), using a non invasive quality control measurement instrument, developed in this University for fast measurement of essential parameters of X-rays diagnostic equipment. In the tests we used a diagnostics Siemens X ray, model Heliofos 4E as our standard equipment. The linearity test of sensor probe and the exposure rate calibration was performed, with a Palmer Dosimeter. For the kVp and exposure time we used a RTI commercial instrument. (author)

  20. Safety code 19: recommended safety procedures for the selection, installation and use of x-ray diffraction equipment

    International Nuclear Information System (INIS)

    1984-01-01

    This document is one of a series of Safety Codes prepared by the Radiation Protection Bureau to set out requirements for the safe use of radiation emitting devices. The equipment and installation guidelines and safety procedures detailed in this Code are primarily for the instruction and guidance of persons employed in Federal Public Service Departments and Agencies, as well as those coming under the jurisdiction of the Canada Labour Code. This Safety Code is also intended to assist other users of X-ray diffraction equipment to select safe equipment and to install and use it so that the radiation hazard to the operator and other persons in its vicinity is negligible. It should be noted that facilities under provincial jurisdiction may be subject to requirements specified under provincial statutes. This Code supersedes Safety Code RPD-SC-7, entitled 'Requirements For Non-Medical X-Ray Equipment, Use and Installation', insofar as X-ray diffraction equipment is concerned, and it is intended to complement X-ray equipment design, construction and performance standards promulgated under the Radiation Emitting Devices Act

  1. Place of digital X-ray tomography in improving the diagnosis of pulmonary tuberculosis, lung cancer and mediastinal abnormality

    International Nuclear Information System (INIS)

    Portnoj, L.M.; Vyatkina, E.I.; Petukhova, N.Yu.; Stashuk, G.A.

    1999-01-01

    To assess the role of current digital X-ray fluorography in the diagnosis of various diseases of the lung (primarily its tuberculosis and cancer, and abnormalities of the mediastinum). 2500 cases from different patient groups (those registered at dispensary or identified at screening, those with a previously verified pathology). In addition to a particularly diagnostic section organizational and methodological problems in the introduction of digital X-ray fluorography into practical public health of Russia are discussed [ru

  2. X-ray diagnostic study on the optimization of digital radiography in dentistry. Optimal exposure conditions for X-ray CCD sensor

    International Nuclear Information System (INIS)

    Hakata, Toshifumi

    2002-01-01

    The purpose of this research is to reduce the patient dose by optimization of irradiation conditions of an X-ray CCD sensor in intra-oral digital radiography. The X-ray diagnosis was divided into two, high quality-of-image diagnosis and low quality-of-image diagnosis, and it optimized by using the exposure of necessary minimum for each. The image quality of CCD was evaluated using the signal-to-noise ratio (SNR) in order to estimate the influence of irradiation conditions. The dose based on CCD maker setting value was set up so that the highest quality of image might be obtained mostly. In low quality-of-image diagnosis, even if it reduced the dose to 13.2% of standard irradiation, SNR was 40% and interpretation was possible. In high quality-of-image diagnosis, even if it reduces the dose to 49% of standard irradiation, SNR remained 80% and there were few differences of the image with a standard. A study of the digital X-ray examination taken at the dental clinic showed high quality-of-image diagnosis was 69% and low quality-of-image one was 31%. When this optimization was performed, it was presumed that reduction of about 62% of the dose is possible. (author)

  3. Evaluation of X-Ray Protective Measurements in Intraoral Radiography Equipped Centers in Yazd

    Directory of Open Access Journals (Sweden)

    D.Goodarzi Pour

    2005-02-01

    Full Text Available Statement of Problem: A few decades have past from using radiographic technology as an accurate paraclinical method and always protective measurements is applicated against ionizing radiation. As dentalradiography is a routine procedure in dentistry the importance of protective strategies is clear.Propose: The aim of this descriptive study is to evaluate the protection principles in centers which haveintraoral radiographic devices in Yazd.Material and Methods: We have considered all three aspects of practitioner, environment and patientprotection using questionnaire and visiting those centers.Results: 33/7% of dental offices ,10 clinics ,3 institution and faculty of dentistry had intraoral radiographicequipments. Stablishment of protection principles for radiographer was favorable. 7.7% of centers had x-ray room with leaded walls, 23.1% had curtain , in 69/2% of centers radiographers stood in correct position anddistance while taking radiograph. Regarding to protection of environment, beams leakage control in 23.1% dental offices, 70% of clinics, all institution and faculty of dentistry have done.Conclusion: Non of the centers used rectangular localizator, thyroid shield, film holder and just some centers used leaded apron in specific circumstances. We have concluded that patient protection constitute less consideration. Generally lack of protective consideration is related to deficient knowledge of operators. Lackof information about protection equipments causes decrease of demanding of these tools and ultimately lack of these equipments in the market.

  4. The dose received by patients during dental X-ray examination and the technical condition of radiological equipment.

    Science.gov (United States)

    Bekas, Marcin; Pachocki, Krzysztof A

    2013-01-01

    Implementation of X-ray dental examination is associated with the patients exposure to ionizing radation. The size of the exposure depends on the type of medical procedure, the technical condition of the X-ray unit and selected exposure conditions. The aim of this study was to determine the dose received by patients during dental X-ray examination and the assessment of the technical condition of medical equipment, The study included a total number of 79 dental X-ray units located in the region of Mazovia. The test methods for the assessment of the technical condition of dental X-ray units and measurement of radiation dose received by patients were based on the procedures elaborated in the Department of Radiation Hygiene and Radiobiology in the National Institute of Public Health - National Institute of Hygiene (Warszawa, Poland) accredited for the certification of compliance with PN-EN 17025. The research found that 69.6% fully meets the criteria set out in the Polish legislation regarding the safe use of ionizing radiation in medicine, while 30.4% did not meet some of them. A tenfold difference in the size of the dose received by patients during dental X-ray examinations was discovered. For example, during a radiography of the canine teeth of a child, the recorded entrance surface dose (ESD) ranged from 72.8 to 2430 microGy with the average value of 689.1 microGy. Cases where the dose reference level defined in Polish legislation of 5 mGy was exceeded were also found. CONCKUSIONS: It is essential to constantly monitor the situation regarding the technical condition of X-ray units which affects the size of the population's exposure to ionizing radiation as well as raising dentists' awareness about the effects of X-rays on the human body.

  5. Development of a handmade device for collimation and central ray alignment tests in medical X-ray equipment

    International Nuclear Information System (INIS)

    Cruz, B.L. da; Brito, E.B.; Gomes, A.S.

    2017-01-01

    Ordinance 453/98 of the Ministry of Health establishes that medical X-ray equipment should be monitored by tests that prove its efficiency. This practice is called quality control (QC), and two important tests jointly evaluate the operation of the collimation and alignment systems of the central axis of the X-ray beam. The low supply and the high cost generate allegations of difficulties in the periodic realization of the tests. The aim of this work is to design, make and evaluate the performance of a handmade device for the mentioned tests, using low cost materials. Once built, the device had its performance evaluated and compared with the traditionally marketed device. The handmade device proved to be fit in its functions. It is possible to make a device that tests X-ray medical equipment, using the radiology technologist himself as the test runner. Radiation protection is promoted and legislation with no real financial burden

  6. Comparison of various filtering methods for digital X-ray image processing

    International Nuclear Information System (INIS)

    Pfluger, T.; Reinfelder, H.E.; Dorschky, K.; Oppelt, A.; Siemens A.G., Erlangen

    1987-01-01

    Three filtering methods are explained and compared that are used for border edge enhancement of digitally processed X-ray images. The filters are compared by two examples, a radiograph of the chest, and one of the knee joint. The unsharpness mask is found to yield the best compromise between edge enhancement and image noise intensifying effect, whereas the results obtained by the high-pass filter or the Wallis filter are less good for diagnostic evaluation. The filtered images better display narrow lines, structural borders and edges, and finely spotted areas, than the original radiograph, so that diagnostic evaluation is easier after image filtering. (orig.) [de

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-08-21

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

  8. Results of improvement of simultaneous and sequential x-ray fluorescence equipment for quantitative routine analysis

    International Nuclear Information System (INIS)

    Zsamboky, Jozsef

    1985-01-01

    Two main types of x-ray fluorescence analyzers measuring sequentially and simultaneously, respectively, the intensities at given wave lengths are described. The main parts of an up to date x-ray fluorescence analyzer are surveyed in detail. The advantages and disadvantages of both methods are discussed. Some results on calibration and optimization are given. (D.Gy.)

  9. Digital tomosynthesis using a 35 mm X-ray cinematogram during an isocentric rotational motion

    International Nuclear Information System (INIS)

    Maeda, Hirofumi; Aikawa, Hisayuki; Maeda, Tohru; Miyake, Hidetoshi; Sugahara, Tetsuo.

    1988-01-01

    Digital tomosynthesis is performed using a 35 mm X-ray cinematogram obtained during an isocentric rotational motion of the cineangiographic apparatus. Formula of image shift for digital tomosynthesis using an isocentric rotational motion is induced by perspective projection and affine transformation. Images of desired layer are aligned at the same point in the image processor and summed. Resultant final image is displayed in sharp focus. We can set tomosynthetic factors on any desired projection, sweep angle and depth as concerns digital tomosynthesis using an isocentric rotational motion. Especially we emphasize that tomosynthesis tilted for central axis of isocentric rotational motion can be obtained, using shear transformation of image in the image processor. (author)

  10. Bayesian Maximum Entropy Based Algorithm for Digital X-ray Mammogram Processing

    Directory of Open Access Journals (Sweden)

    Radu Mutihac

    2009-06-01

    Full Text Available Basics of Bayesian statistics in inverse problems using the maximum entropy principle are summarized in connection with the restoration of positive, additive images from various types of data like X-ray digital mammograms. An efficient iterative algorithm for image restoration from large data sets based on the conjugate gradient method and Lagrange multipliers in nonlinear optimization of a specific potential function was developed. The point spread function of the imaging system was determined by numerical simulations of inhomogeneous breast-like tissue with microcalcification inclusions of various opacities. The processed digital and digitized mammograms resulted superior in comparison with their raw counterparts in terms of contrast, resolution, noise, and visibility of details.

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

    International Nuclear Information System (INIS)

    Sliva, K.

    1992-01-01

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

  12. The physical and biomedical characteristics of the novel transmission type X-ray equipment

    International Nuclear Information System (INIS)

    Hsu, S.M.; Wang, S.F.; Hsieh, Y.J.; Cheng, C.C.; Liao, Y.J.

    2016-01-01

    The radiation output characteristics of the transmission-target X-ray tube are different from those of the traditional reflection-target X-ray tube. The aims of this study were to compare the differences of output dose and spectrum between these two X-ray tubes under the same conditions. The biomedical applications of the transmission-target X-ray in liver cancer cells were also evaluated. For these two systems, the dose output and the mAs appeared to have good linear relations; the dose output and kVp variations also had positive relations. However, under the same parameters, the dose output of transmission-target X-ray system was 2.64–3.21 times higher than the reflection-target system, implying that the transmission-target system had a higher X-ray production rate. The K characteristic radiations reach 22.96% and 8.91% of the spectrum in transmission-target and reflection-target, respectively. The spectrum measurements showed that the transmission-target system had more obvious output of K characteristic radiation. The 1 Gy of transmission-target can induce 16%–23% of cytotoxicity in liver cancer cells. Concerning the synergic effects of transmission-target combined with rose bengal, the data showed that 1 Gy of transmission-target exposure augment the 24%–28% of cytotoxicity at low dose of rose bengal treated condition. - Highlights: • The transmission-target X-ray system had a higher X-ray production rate. • The transmission-target X-ray system had more obvious output of K characteristic radiation. • The transmission-target X-ray enhanced rose bengal induced cytotoxicity in liver cancer cells.

  13. Direct magnification radiography of newborn with mobile X-ray equipment

    International Nuclear Information System (INIS)

    Fukai, Kazuhiko; Kigure, Hatsuo; Hatori, Noboru; Shinohara, Yasuji.

    1989-01-01

    Small patient size is a major factor of the difficulty in interpreting the newborn infant radiograph. Direct radiographic magnification can be employed to relieve this problem and special positioning devices were made to image the infant, confined to incubator and connected to life-supporting systems. The mobile X-ray equipment with a microfocus (0.2 mm) radiographic tube, a rare-earth high-speed recording system and carbon cassette were combined to obtain a radiograph at magnification of 1.5-2.0. Image quality was superior to that of conventional contact radiographic system, but infant radiation exposure was 26% more than that of conventional study. Although direct radiographic magnification was very useful to recognize subtle or equivocal abnormality which could not be made from conventional image, its application should be restricted to specific disease at this present, considering infant radiation exposures. This technique will have wide clinical application when radiation exposure can be reduced by using other recording system such as computed radiography (CR). (author)

  14. Equipment performance and radiation protection status in X-ray fluoroscopy units in Sudan

    International Nuclear Information System (INIS)

    Ahmed, N. A.; Nayl, A. I.; Suliman, I. I.

    2012-01-01

    The number of fluoroscopy and fluoroscopically guided procedures has been substantially growing in developing countries at the same time advanced and sophisticated equipment are used in some hospitals. However, radiation protection requirements are not necessarily well adopted. In this study nine fluoroscopy X-ray units in Sudan were examined for compliance with international standards. The tests included: beam quality, entrance surface air kerma, image quality and radiation field measurements. Staff radiation protection tools such as lead aprons and eye glasses were also visually examined to find out whether international recommendations were fulfilled and to determine the level of staff awareness. The measured peak tube voltage deviation exceeded the recommended tolerance level in 30 % of the measurements. The results of patient doses measurements exceeded the recommended reference dose levels in 43 % of the measurements; however image quality and radiation field generally fulfilled the requirements for most units. The study revealed that a considerable number of fluoroscopy units were not performing according to the international standards and highlights the need of optimisation of radiation protection. (authors)

  15. Construction of an analytic-realistic phantom for adaptation of the radiographic techniques in any conventional X-ray equipment

    International Nuclear Information System (INIS)

    Pina, D.R.; Ghilardi Netto, T.; Trad, C.S.; Brochi, M.A. Corte; Duarte, S.B.; Pina, S.R.

    2001-01-01

    In the present work we construct a homogeneous phantom, for calibrating the X-ray beam. Each homogeneous phantom was used in the time-scale sensitometric method for obtaining a radiographic technique which is able to produce in the film, an optical density around 1,0 higher than the density of base plus fog. These radiographic techniques were applied in a anthropomorphic phantom (Rando) and its images were analyzed by specialists in radiology. They identified the best image and then a ideal radiographic technique for a standard patient with smaller doses, at any conventional X-ray equipment. (author)

  16. X-RAY-EMITTING STARS IDENTIFIED FROM THE ROSAT ALL-SKY SURVEY AND THE SLOAN DIGITAL SKY SURVEY

    International Nuclear Information System (INIS)

    Agueeros, Marcel A.; Newsom, Emily R.; Anderson, Scott F.; Hawley, Suzanne L.; Silvestri, Nicole M.; Szkody, Paula; Covey, Kevin R.; Posselt, Bettina; Margon, Bruce; Voges, Wolfgang

    2009-01-01

    The ROSAT All-Sky Survey (RASS) was the first imaging X-ray survey of the entire sky. Combining the RASS Bright and Faint Source Catalogs yields an average of about three X-ray sources per square degree. However, while X-ray source counterparts are known to range from distant quasars to nearby M dwarfs, the RASS data alone are often insufficient to determine the nature of an X-ray source. As a result, large-scale follow-up programs are required to construct samples of known X-ray emitters. We use optical data produced by the Sloan Digital Sky Survey (SDSS) to identify 709 stellar X-ray emitters cataloged in the RASS and falling within the SDSS Data Release 1 footprint. Most of these are bright stars with coronal X-ray emission unsuitable for SDSS spectroscopy, which is designed for fainter objects (g > 15 [mag]). Instead, we use SDSS photometry, correlations with the Two Micron All Sky Survey and other catalogs, and spectroscopy from the Apache Point Observatory 3.5 m telescope to identify these stellar X-ray counterparts. Our sample of 707 X-ray-emitting F, G, K, and M stars is one of the largest X-ray-selected samples of such stars. We derive distances to these stars using photometric parallax relations appropriate for dwarfs on the main sequence, and use these distances to calculate L X . We also identify a previously unknown cataclysmic variable (CV) as a RASS counterpart. Separately, we use correlations of the RASS and the SDSS spectroscopic catalogs of CVs and white dwarfs (WDs) to study the properties of these rarer X-ray-emitting stars. We examine the relationship between (f X /f g ) and the equivalent width of the Hβ emission line for 46 X-ray-emitting CVs and discuss tentative classifications for a subset based on these quantities. We identify 17 new X-ray-emitting DA (hydrogen) WDs, of which three are newly identified WDs. We report on follow-up observations of three candidate cool X-ray-emitting WDs (one DA and two DB (helium) WDs); we have not

  17. Determination of doses and cancer risk to patients undergoing digital x-ray examinations at the Tamale Teaching Hospital

    International Nuclear Information System (INIS)

    Aweligiba, S.A.

    2015-07-01

    Entrance surface and effective doses as well as cancer risk to patients for three common radiological examinations were estimated at the radiology department of the Tamale Teaching Hospital. The quality control assessment indicated that the digital x-ray equipment used, performed self-consistently in line with acceptable performance criteria. The study included eighty-two (82) adult patients undergoing three x-ray imaging modalities; Chest, Abdomen and Pelvis Examinations. From the study the mean entrance dose to abdomen and pelvis were found to be 0.6 ± 0.2 mGy whiles that of chest was found to be 0.2 ± 0.1 mGy. These were found to be lower than results of studies carried out elsewhere. The effective dose to patient was computed using PCXMC 2.0 software. The results shows an average effective dose of 0.036 mSv, 0.084 mSv and 0.067 mSv for chest, abdomen and pelvis examinations respectively. The risk of radiation induced cancer as a result to entrance surface dose was found to be 5.68 x 10-5 %, 1.58 x 10-4 % and 1.49 x 10-4 % for Chest, Abdomen and Pelvis examinations respectively. The third quartile values of the entrance surface dose were found to be lower than recommended diagnostic reference levels published by NRPB, UK and the IAEA for the examinations under study. (author)

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

    Science.gov (United States)

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

    2012-04-01

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

  19. A digital miniature x-ray tube with a high-density triode carbon nanotube field emitter

    International Nuclear Information System (INIS)

    Jeong, Jin-Woo; Kang, Jun-Tae; Choi, Sungyoul; Kim, Jae-Woo; Song, Yoon-Ho; Ahn, Seungjoon

    2013-01-01

    We have fabricated a digital miniature x-ray tube (6 mm in diameter and 32 mm in length) with a high-density triode carbon nanotube (CNT) field emitter for special x-ray applications. The triode CNT emitter was densely formed within a diameter of below 4 mm with the focusing-functional gate. The brazing process enables us to obtain and maintain a desired vacuum level for the reliable electron emission from the CNT emitters after the vacuum packaging. The miniature x-ray tube exhibited a stable and reliable operation over 250 h in a pulse mode at an anode voltage of above 25 kV.

  20. Review of the regulation on the installation and use of X-ray equipment for medical diagnosis

    International Nuclear Information System (INIS)

    Alvarez Garcia, C.; Arguelles Sanchez, R.; Franco Artero, P.; Gil Gahete, M.; Rodriguez Marti, M.; Rueda Guerrero, M. D.; Villarroel Gonzalez-Eipe, R.

    2009-01-01

    The first regulation on the installation and use of X-ray equipment for the purposes of medical diagnosis was approved in 1991. This allowed the control of the safety of such equipment to be significantly improved. Royal Decree 1891/1991 has now been subjected to a review to update its contents and include the regulatory changes that have been incorporated in later standards, this having materialised with the Royal Decree 1085/2009, of July 3rd. (Author)

  1. Qualitative Evaluation of Digital Hand X-rays is Not a Reliable Method to Assess Bone Mineral Density

    Directory of Open Access Journals (Sweden)

    AndrewJ. Miller

    2017-01-01

    Full Text Available Object: The gold standard for evaluating bone mineral density is dual energy x-ray absorptiometry (DEXA.  Prior studies have shown poor reliability using analog wrist X-rays in diagnosing osteoporosis. Our goal was to investigate if there was improved diagnostic value to visual assessment of digital hand X-rays in osteoporosis screening. We hypothesized that similar to analog counterparts, digital hand X-rays have poor correlation and reliability in determining bone mineral density (BMD relative to DEXA.Methods: We prospectively evaluated female patients older than 65 years who presented to our hand clinic with digital hand and wrist X-rays as part of their evaluation over six months. Patients who had a fracture and were without DEXA scans within the past two years were excluded. Five fellowship-trained hand surgeons, blinded to DEXA T-scores, evaluated the x-rays over two assessments separated by four weeks and classified them as osteoporotic, osteopenic, or normal BMD.  Accuracy relative to DEXA T-score, interobserver and intraobserver rates were calculated.Results: Thirty four patients met the inclusion criteria and a total of 340 x-rays reviews were performed.  The assessments were correct in 169 cases (49% as compared to the DEXA T-scores. A mean weighted kappa coefficient of agreement between observers was 0.29 (range 0.02-0.41 reflecting a fair agreement. The first and second assessment for all five physicians was 0.46 (range 0.19-0.78 reflecting a moderate agreement.  Grouping osteoporosis and osteopenia together compared to normal, the accuracy, interobserver and intraobserver rates increased to 63%, 0.42 and 0.54 respectively.Conclusion: Abnormally low BMD is a common occurrence in patients treated for upper extremity disorders. There is poor accuracy relative to DEXA scan and only fair agreement in diagnosing osteoporosis using visual assessments of digital x-rays.

  2. Compliance testing of medical diagnostic x-ray equipment: three years experience of a public hospital in western Australia

    International Nuclear Information System (INIS)

    Tuchyna, T.; Jacob, C.S.

    2000-01-01

    Full text: A formal compliance testing program which began on 1 January 1997 called for all medical and diagnostic x-ray equipment to be tested according to protocols established by the Western Australian Radiological Council. This work describes the impact of the legislation three years post implementation on a major teaching Hospital with 45 x-ray tubes located throughout 37 rooms. Testing is performed prior to scheduled service by licensed compliance testers according to test methods specified in the Western Australian Compliance Testing Workbook, 1997. A dedicated non-invasive x-ray beam analyser is instrumental in accurately determining radiation output parameters of the generator and x-ray tube. Assessment of compliance is determined by a Qualified Expert. Repair and re-testing of non-compliant items is coordinated with service personnel. Notices of non-compliance were received for approximately 60% of the equipment in the Hospital following the equipment' first annual test. Reasons and seriousness of failure varied according to equipment category, test category, equipment use and age. The majority of non-compliance issues were resolved within 90 days. At the end of the third year of testing, approximately 75% of the x-ray units tested met the compliance criteria. The main reasons for non-compliance were found to be design limitations associated with old technology and the current radiation legislation that makes it difficult for older equipment to meet the stringent criteria. The number and categories of failure did not significantly decrease in the second or third years of testing. Exemptions from compliance criteria have been sought for two units on the basis of age and design. Units unable to meet the criteria following several repair attempts or where the cost of repair was deemed not justified, were decommissioned. Formal testing of medical x-ray equipment has demonstrated various non-compliance issues that did not significantly improve during the

  3. A study on developpement of guideline on writing technical document for electrical medical devices: Dental x-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Youl; Kim, Jae Ryang; Lee, Jun Ho; Park, Chang Won [Division of Medical Device Research, National Institute of Food and Drug Safety Evaluation, Mnistry of Food and Drug Safety (Korea, Republic of)

    2016-12-15

    Due to recent population aging, the number of check-up for senior citizens has increased steadily. According to this trend, the market size of dental X-ray equipment and the number of approval and review for these devices have simultaneously increased. The technical document of medical device is required for approval and review for medical device, and medical device companies needs to have work comprehension and expertise, as the document needs to include the overall contents such as performances, test criteria, etc.. Yet, since most of domestic manufacturers or importers of medical devices are small businesses, it is difficult for them to recruit professional manpower for approval of medical devices, and submission of inaccurate technical documents has increased. These problems lead to delay of the approval process and to difficulties in quick entering into the market. Especially, the Ministry of Food and Drug safety (MFDS) standards of a dental extra-oral X-ray equipment, a dental intra-oral X-ray equipment, an arm-type computed tomography, and a portable X-ray system have been recently enacted or not. this guideline of dental X-ray equipment adjusting revised standards was developed to help relative companies and reviewers. For this study, first, the methods to write technical document have been reviewed with revised international and domestic regulations and system. Second, the domestic and foreign market status of each item has been surveyed and analyzed. Third, the contents of technical documents already approved by MFDS have been analyzed to select the correct example, test items, criteria, and methods. Finally, the guideline has been developed based on international and domestic regulation, through close review of a consultative body composed of academic, industrial, research institute and government experts.

  4. A study on developpement of guideline on writing technical document for electrical medical devices: Dental x-ray equipment

    International Nuclear Information System (INIS)

    Lee, Seung Youl; Kim, Jae Ryang; Lee, Jun Ho; Park, Chang Won

    2016-01-01

    Due to recent population aging, the number of check-up for senior citizens has increased steadily. According to this trend, the market size of dental X-ray equipment and the number of approval and review for these devices have simultaneously increased. The technical document of medical device is required for approval and review for medical device, and medical device companies needs to have work comprehension and expertise, as the document needs to include the overall contents such as performances, test criteria, etc.. Yet, since most of domestic manufacturers or importers of medical devices are small businesses, it is difficult for them to recruit professional manpower for approval of medical devices, and submission of inaccurate technical documents has increased. These problems lead to delay of the approval process and to difficulties in quick entering into the market. Especially, the Ministry of Food and Drug safety (MFDS) standards of a dental extra-oral X-ray equipment, a dental intra-oral X-ray equipment, an arm-type computed tomography, and a portable X-ray system have been recently enacted or not. this guideline of dental X-ray equipment adjusting revised standards was developed to help relative companies and reviewers. For this study, first, the methods to write technical document have been reviewed with revised international and domestic regulations and system. Second, the domestic and foreign market status of each item has been surveyed and analyzed. Third, the contents of technical documents already approved by MFDS have been analyzed to select the correct example, test items, criteria, and methods. Finally, the guideline has been developed based on international and domestic regulation, through close review of a consultative body composed of academic, industrial, research institute and government experts

  5. Simple microprocessor-based system for upgrading existing X-ray equipment for analysis

    International Nuclear Information System (INIS)

    Souza, A.M. de

    1986-01-01

    A data acquisition and processing device appropriate for X-ray analysis and goniometer control was built. A conventional Z-80 based systems was used, and the interfacing architeture and the applicable soft-ware are described. The advantages and new possibilities of the automated instrument as compared to previous ones are listed. It is shown that the X-ray diffraction and fluorescence techniques can take advantage of the automation using existing instruments. (Author) [pt

  6. Methodology of ionizing radiation measurement, from x-ray equipment, for radiation protection

    International Nuclear Information System (INIS)

    Caballero, Katia C.S.; Borges, Jose C.

    1996-01-01

    Most of X-rays beam used for diagnostic, are short exposure time (milliseconds). Exception are those used in fluoroscopy. measuring instruments (area monitors with ionizing chambers or Geiger tubes) used in hospitals and clinics, in general, have characteristic answer time not adequate to X-rays beams length in time. Our objective was to analyse instruments available commercially, to prepare a measuring methodology for direct and secondary beams, in order to evaluate protection barriers for beams used in diagnostic radiology installations. (author)

  7. Heel effect adaptive flat field correction of digital x-ray detectors

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yongjian [X-ray Products, Varian Medical Systems Inc., Liverpool, New York 13088 (United States); Wang, Jue [Department of Mathematics, Union College, Schenectady, New York 12308 (United States)

    2013-08-15

    Purpose: Anode heel effect renders large-scale background nonuniformities in digital radiographs. Conventional offset/gain calibration is performed at mono source-to-image distance (SID), and disregards the SID-dependent characteristic of heel effect. It results in a residual nonuniform background in the corrected radiographs when the SID settings for calibration and correction differ. In this work, the authors develop a robust and efficient computational method for digital x-ray detector gain correction adapted to SID-variant heel effect, without resorting to physical filters, phantoms, complicated heel effect models, or multiple-SID calibration and interpolation.Methods: The authors present the Duo-SID projection correction method. In our approach, conventional offset/gain calibrations are performed only twice, at the minimum and maximum SIDs of the system in typical clinical use. A fast iterative separation algorithm is devised to extract the detector gain and basis heel patterns from the min/max SID calibrations. The resultant detector gain is independent of SID, while the basis heel patterns are parameterized by the min- and max-SID. The heel pattern at any SID is obtained from the min-SID basis heel pattern via projection imaging principles. The system gain desired at a specific acquisition SID is then constructed using the projected heel pattern and detector gain map.Results: The method was evaluated for flat field and anatomical phantom image corrections. It demonstrated promising improvements over interpolation and conventional gain calibration/correction methods, lowering their correction errors by approximately 70% and 80%, respectively. The separation algorithm was able to extract the detector gain and heel patterns with less than 2% error, and the Duo-SID corrected images showed perceptually appealing uniform background across the detector.Conclusions: The Duo-SID correction method has substantially improved on conventional offset/gain corrections for

  8. Heel effect adaptive flat field correction of digital x-ray detectors

    International Nuclear Information System (INIS)

    Yu, Yongjian; Wang, Jue

    2013-01-01

    Purpose: Anode heel effect renders large-scale background nonuniformities in digital radiographs. Conventional offset/gain calibration is performed at mono source-to-image distance (SID), and disregards the SID-dependent characteristic of heel effect. It results in a residual nonuniform background in the corrected radiographs when the SID settings for calibration and correction differ. In this work, the authors develop a robust and efficient computational method for digital x-ray detector gain correction adapted to SID-variant heel effect, without resorting to physical filters, phantoms, complicated heel effect models, or multiple-SID calibration and interpolation.Methods: The authors present the Duo-SID projection correction method. In our approach, conventional offset/gain calibrations are performed only twice, at the minimum and maximum SIDs of the system in typical clinical use. A fast iterative separation algorithm is devised to extract the detector gain and basis heel patterns from the min/max SID calibrations. The resultant detector gain is independent of SID, while the basis heel patterns are parameterized by the min- and max-SID. The heel pattern at any SID is obtained from the min-SID basis heel pattern via projection imaging principles. The system gain desired at a specific acquisition SID is then constructed using the projected heel pattern and detector gain map.Results: The method was evaluated for flat field and anatomical phantom image corrections. It demonstrated promising improvements over interpolation and conventional gain calibration/correction methods, lowering their correction errors by approximately 70% and 80%, respectively. The separation algorithm was able to extract the detector gain and heel patterns with less than 2% error, and the Duo-SID corrected images showed perceptually appealing uniform background across the detector.Conclusions: The Duo-SID correction method has substantially improved on conventional offset/gain corrections for

  9. Bone loss in unclassified polyarthritis and early rheumatoid arthritis is better detected by digital x ray radiogrammetry than dual x ray absorptiometry: relationship with disease activity and radiographic outcome

    DEFF Research Database (Denmark)

    Jensen, T; Klarlund, Mette; Hansen, M

    2004-01-01

    OBJECTIVE: To compare changes in regional bone mineral density (BMD) of the metacarpal joints measured by dual x ray absorptiometry (DXA) and digital x ray radiogrammetry (DXR) in relation to disease activity and radiographic outcome in a two year follow up study of patients with early RA...... polyarthritis. The patients with RA were divided into groups according to mean disease activity, average glucocorticoid dose, and MRI and x ray detected bone erosions in the hands. Clinical and biochemical measurements were made every month and an x ray examination of the hands and BMD of the metacarpal joints...

  10. The performance of a prototype device designed to evaluate general quality parameters of X-ray equipment

    International Nuclear Information System (INIS)

    Murata, C.H.; Fernandes, D.C.; Lavínia, N.C.; Caldas, L.V.E; Pires, S.R; Medeiros, R.B.

    2014-01-01

    The performance of radiological equipment can be assessed using non-invasive methods and portable instruments that can analyze an X-ray beam with just one exposure. These instruments use either an ionization chamber or a state solid detector (SSD) to evaluate X-ray beam parameters. In Brazil, no such instruments are currently being manufactured; consequently, these instruments come at a higher cost to users due to importation taxes. Additionally, quality control tests are time consuming and impose a high workload on the X-ray tubes when evaluating their performance parameters. The assessment of some parameters, such as the half-value layer (HVL), requires several exposures; however, this can be reduced by using a SSD that requires only a single exposure. One such SSD uses photodiodes designed for high X-ray sensitivity without the use of scintillation crystals. This sensitivity allows one electron-hole pair to be created per 3.63 eV of incident energy, resulting in extremely high and stable quantum efficiencies. These silicon photodiodes operate by absorbing photons and generating a flow of current that is proportional to the incident power. The aim of this study was to show the response of the solid sensor PIN RD100A detector in a multifunctional X-ray analysis system that is designed to evaluate the average peak voltage (kVp), exposure time, and HVL of radiological equipment. For this purpose, a prototype board that uses four SSDs was developed to measure kVp, exposure time, and HVL using a single exposure. The reproducibility and accuracy of the results were compared to that of different X-ray beam analysis instruments. The kVp reproducibility and accuracy results were 2% and 3%, respectively; the exposure time reproducibility and accuracy results were 2% and 1%, respectively; and the HVL accuracy was ±2%. The prototype's methodology was able to calculate these parameters with appropriate reproducibility and accuracy. Therefore, the prototype can be considered

  11. Evaluation of the quality parameters of mobile X-ray units equipment used for radiodiagnostic in public institutions of Sergipe

    International Nuclear Information System (INIS)

    Oliveira, Celso A.; Santos, Lucas R. dos; Silva, Fabio A.R.; Souza, Divanizia N.

    2008-01-01

    This project was started having as main objective to observe the diagnosis quality offered by mobile x-ray units utilized in a health care institution. In this work we are reporting the first results obtained from three equipment used by a public institution inspected on the state of Sergipe, Brazil. During the verification visits at institution the radiology technicians were questioned about specific maintenances performed on the equipment and the operating procedures used. Moreover, some beams parameters were verified as dose, dose rate, and peak voltage and exposition time. The obtained results showed a good index of reproducibility and linearity of the operation parameters, of the kerma air rate and exposition time. However, to the kVp tests were observed variations up to 20% between the nominal value used and the value measured on the X-ray units. The test results of the focal point are in accordance with the acceptable standards. The analyses of equipment and the answered questionnaire showed that have not been performed periodic maintenances in the equipment, therefore some of the equipment do not present satisfactory requirements of operating, their do not make use of luminous field nether collimator or the scale meter to checking the source to surface distance. The main factor that can explains the negative results is the absence of a continue quality program associated with the unsatisfactory maintenances. The health care institutions evaluated are introducing a permanent quality program to the X-ray devices. (author)

  12. Film-based X-ray tomography combined with digital image processing: investigation of an ancient pattern-welded sword

    International Nuclear Information System (INIS)

    Lindegaard-Andersen, A.; Vedel, T.; Jeppesen, L.; Gottlieb, B.

    1988-01-01

    Film-based X-ray tomography and digital image processing have been used to investigate an inhomogeneous object of non-circular cross-section. The feasibility of using digital image processing to compensate for the poor contrast resolution inherent in film-based tomography has been demonstrated. (author)

  13. Digital Image Correlation of 2D X-ray Powder Diffraction Data for Lattice Strain Evaluation

    Directory of Open Access Journals (Sweden)

    Hongjia Zhang

    2018-03-01

    Full Text Available High energy 2D X-ray powder diffraction experiments are widely used for lattice strain measurement. The 2D to 1D conversion of diffraction patterns is a necessary step used to prepare the data for full pattern refinement, but is inefficient when only peak centre position information is required for lattice strain evaluation. The multi-step conversion process is likely to lead to increased errors associated with the ‘caking’ (radial binning or fitting procedures. A new method is proposed here that relies on direct Digital Image Correlation analysis of 2D X-ray powder diffraction patterns (XRD-DIC, for short. As an example of using XRD-DIC, residual strain values along the central line in a Mg AZ31B alloy bar after 3-point bending are calculated by using both XRD-DIC and the conventional ‘caking’ with fitting procedures. Comparison of the results for strain values in different azimuthal angles demonstrates excellent agreement between the two methods. The principal strains and directions are calculated using multiple direction strain data, leading to full in-plane strain evaluation. It is therefore concluded that XRD-DIC provides a reliable and robust method for strain evaluation from 2D powder diffraction data. The XRD-DIC approach simplifies the analysis process by skipping 2D to 1D conversion, and opens new possibilities for robust 2D powder diffraction data analysis for full in-plane strain evaluation.

  14. Application of digital tomosynthesis (DTS) of optimal deblurring filters for dental X-ray imaging

    International Nuclear Information System (INIS)

    Oh, J. E.; Cho, H. S.; Kim, D. S.; Choi, S. I.; Je, U. K.

    2012-01-01

    Digital tomosynthesis (DTS) is a limited-angle tomographic technique that provides some of the tomographic benefits of computed tomography (CT) but at reduced dose and cost. Thus, the potential for application of DTS to dental X-ray imaging seems promising. As a continuation of our dental radiography R and D, we developed an effective DTS reconstruction algorithm and implemented it in conjunction with a commercial dental CT system for potential use in dental implant placement. The reconstruction algorithm employed a backprojection filtering (BPF) method based upon optimal deblurring filters to suppress effectively both the blur artifacts originating from the out-focus planes and the high-frequency noise. To verify the usefulness of the reconstruction algorithm, we performed systematic simulation works and evaluated the image characteristics. We also performed experimental works in which DTS images of enhanced anatomical resolution were successfully obtained by using the algorithm and were promising to our ongoing applications to dental X-ray imaging. In this paper, our approach to the development of the DTS reconstruction algorithm and the results are described in detail.

  15. Digital Image Correlation of 2D X-ray Powder Diffraction Data for Lattice Strain Evaluation

    Science.gov (United States)

    Zhang, Hongjia; Sui, Tan; Daisenberger, Dominik; Fong, Kai Soon

    2018-01-01

    High energy 2D X-ray powder diffraction experiments are widely used for lattice strain measurement. The 2D to 1D conversion of diffraction patterns is a necessary step used to prepare the data for full pattern refinement, but is inefficient when only peak centre position information is required for lattice strain evaluation. The multi-step conversion process is likely to lead to increased errors associated with the ‘caking’ (radial binning) or fitting procedures. A new method is proposed here that relies on direct Digital Image Correlation analysis of 2D X-ray powder diffraction patterns (XRD-DIC, for short). As an example of using XRD-DIC, residual strain values along the central line in a Mg AZ31B alloy bar after 3-point bending are calculated by using both XRD-DIC and the conventional ‘caking’ with fitting procedures. Comparison of the results for strain values in different azimuthal angles demonstrates excellent agreement between the two methods. The principal strains and directions are calculated using multiple direction strain data, leading to full in-plane strain evaluation. It is therefore concluded that XRD-DIC provides a reliable and robust method for strain evaluation from 2D powder diffraction data. The XRD-DIC approach simplifies the analysis process by skipping 2D to 1D conversion, and opens new possibilities for robust 2D powder diffraction data analysis for full in-plane strain evaluation. PMID:29543728

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  17. Digital Interface Modules for Active-Readout X-Ray Spectrometer.

    Science.gov (United States)

    1985-03-01

    x - ray sensitivity. The x - ray absorption coefficients tabulated by McMasters , et al...provides x - ray spectrographic data with all instrument response factors removed. v %, . % CONVERSION TABLE CONVERSION FACTORS FOR U.S. CUSTOMARY TO METRIC...LLNL document UCRL-50174) have been used to calculate the values of TKIM and TBe listed in Tables 1 through 3. The Reticon x - ray sensitivity

  18. The x-ray light valve: A potentially low-cost, digital radiographic imaging system-concept and implementation considerations

    International Nuclear Information System (INIS)

    Webster, Christie Ann; Koprinarov, Ivaylo; Germann, Stephen; Rowlands, J. A.

    2008-01-01

    New x-ray radiographic systems based on large-area flat-panel technology have revolutionized our capability to produce digital x-ray images. However, these imagers are extraordinarily expensive compared to the systems they are replacing. Hence, there is a need for a low-cost digital imaging system for general applications in radiology. A novel potentially low-cost radiographic imaging system based on established technologies is proposed--the X-Ray Light Valve (XLV). This is a potentially high-quality digital x-ray detector made of a photoconducting layer and a liquid-crystal cell, physically coupled in a sandwich structure. Upon exposure to x rays, charge is collected on the surface of the photoconductor. This causes a change in the optical properties of the liquid-crystal cell and a visible image is generated. Subsequently, it is digitized by a scanned optical imager. The image formation is based on controlled modulation of light from an external source. The operation and practical implementation of the XLV system are described. The potential performance of the complete system and issues related to sensitivity, spatial resolution, noise, and speed are discussed. The feasibility of clinical use of an XLV device based on amorphous selenium (a-Se) as the photoconductor and a reflective electrically controlled birefringence cell is analyzed. The results of our analysis indicate that the XLV can potentially be adapted to a wide variety of radiographic tasks

  19. X-ray film digitization using a personal computer and hand-held scanner: a simple technique for storing images

    International Nuclear Information System (INIS)

    Munoz-Nunez, C. F.; Lloret-Alcaniz, A.

    1998-01-01

    To develop a simple, low-cost technique for the digitization of X-ray films for personal use. A 66-MHz 486 PC with 8 MB of RAM, a Logitech ScanMan 256 hand-held scanner and a standard negatoscope with the power source converted to direct current. Although the system was originally designed for the digitization of mammographies, it has also been used with computed tomography, magnetic resonance, digital angiography and ultrasonographic images, as well as plain X-rays. After a minimal training period, the system digitized X-ray films easily and rapidly. Although the scanning values vary depending on the type of image to be digitized, an input spatial resolution of 200 dpi and a contrast resolution of 256 levels of gray are generally adequate. Of the storage formats tested, JPEG presented the best quality/image size ratio. A simple, low-cost technique has been developed for the digitization of X-ray films. This technique enables the storage of images in a digital format, thus facilitating their presentation and transmission. (Author) 9 refs

  20. Three Dimensional Digital Sieving of Asphalt Mixture Based on X-ray Computed Tomography

    Directory of Open Access Journals (Sweden)

    Chichun Hu

    2017-07-01

    Full Text Available In order to perform three-dimensional digital sieving based on X-ray computed tomography images, the definition of digital sieve size (DSS was proposed, which was defined as the minimum length of the minimum bounding squares of all possible orthographic projections of an aggregate. The corresponding program was developed to reconstruct aggregate structure and to obtain DSS. Laboratory experiments consisting of epoxy-filled aggregate specimens were conducted to investigate the difference between mechanical sieve analysis and the digital sieving technique. It was suggested that concave surface of aggregate was the possible reason for the disparity between DSS and mechanical sieve size. A comparison between DSS and equivalent diameter was also performed. Moreover, the digital sieving technique was adopted to evaluate the gradation of stone mastic asphalt mixtures. The results showed that the closest proximity of the laboratory gradation curve was achieved by calibrated DSS, among gradation curves based on calibrated DSS, un-calibrated DSS and equivalent diameter.

  1. Analytical approximations to the Hotelling trace for digital x-ray detectors

    Science.gov (United States)

    Clarkson, Eric; Pineda, Angel R.; Barrett, Harrison H.

    2001-06-01

    The Hotelling trace is the signal-to-noise ratio for the ideal linear observer in a detection task. We provide an analytical approximation for this figure of merit when the signal is known exactly and the background is generated by a stationary random process, and the imaging system is an ideal digital x-ray detector. This approximation is based on assuming that the detector is infinite in extent. We test this approximation for finite-size detectors by comparing it to exact calculations using matrix inversion of the data covariance matrix. After verifying the validity of the approximation under a variety of circumstances, we use it to generate plots of the Hotelling trace as a function of pairs of parameters of the system, the signal and the background.

  2. Feasibility study of flexible flat-panel X-ray detectors for digital radiography

    International Nuclear Information System (INIS)

    Joe, Ok La; Yun, Seung Man; Kim, Ho Kyung

    2010-01-01

    Flexible flat-panel detectors (FPDs), which utilize both organic photodiode (OPD) and organic thin-film transistor (OTFT) technologies, are recently concerned in digital radiography. The flexible FPD has several potential advantages, such as high accessibility to patient, avoidance of geometrical burr due to the oblique angle incidence of X-ray, great reduction in manufacturing cost due to jet-printing. At once, The OPD/OTFT arrays were fabricated by jet-printing techniques, mechanical robustness due to plastic substrates, and so on. In this study, we have investigated the feasibility of flexible FPD by comparing theoretical detective quantum efficiency (DQE) with that of the conventional amorphous silicon-based FPD. We chose copper phthalocyanine-fullerene (CuPc-C60) organic materials for the construction of the flexible FPD. DQE was calculated by the linear-systems transfer theory

  3. Accurate joint space quantification in knee osteoarthritis: a digital x-ray tomosynthesis phantom study

    Science.gov (United States)

    Sewell, Tanzania S.; Piacsek, Kelly L.; Heckel, Beth A.; Sabol, John M.

    2011-03-01

    The current imaging standard for diagnosis and monitoring of knee osteoarthritis (OA) is projection radiography. However radiographs may be insensitive to markers of early disease such as osteophytes and joint space narrowing (JSN). Relative to standard radiography, digital X-ray tomosynthesis (DTS) may provide improved visualization of the markers of knee OA without the interference of superimposed anatomy. DTS utilizes a series of low-dose projection images over an arc of +/-20 degrees to reconstruct tomographic images parallel to the detector. We propose that DTS can increase accuracy and precision in JSN quantification. The geometric accuracy of DTS was characterized by quantifying joint space width (JSW) as a function of knee flexion and position using physical and anthropomorphic phantoms. Using a commercially available digital X-ray system, projection and DTS images were acquired for a Lucite rod phantom with known gaps at various source-object-distances, and angles of flexion. Gap width, representative of JSW, was measured using a validated algorithm. Over an object-to-detector-distance range of 5-21cm, a 3.0mm gap width was reproducibly measured in the DTS images, independent of magnification. A simulated 0.50mm (+/-0.13) JSN was quantified accurately (95% CI 0.44-0.56mm) in the DTS images. Angling the rods to represent knee flexion, the minimum gap could be precisely determined from the DTS images and was independent of flexion angle. JSN quantification using DTS was insensitive to distance from patient barrier and flexion angle. Potential exists for the optimization of DTS for accurate radiographic quantification of knee OA independent of patient positioning.

  4. The impact of technical conditions of X-ray imaging on reproducibility and precision of digital computer-assisted X-ray radiogrammetry (DXR)

    International Nuclear Information System (INIS)

    Malich, A.; Boettcher, J.; Pfeil, A.; Sauner, D.; Heyne, J.P.; Petrovitch, A.; Hansch, A.; Kaiser, W.A.; Linss, W.

    2004-01-01

    To evaluate the reproducibility of imaging and analysis for bone mineral density (BMD) determination using digital computer-assisted X-ray radiogrammetry (DXR; Pronosco X-posure, version V.2, Sectra Pronosco, Denmark); to verify potential factors that influence BMD extrapolation such as tube voltage, film-focus distance (FFD), film quality and brand (Kodak T-MAT-Plus, Konika SRH, Agfa Scopix), imaging technology (conventional, digital), imaging system (Kodak, Agfa) and exposure level (mAs); and to clarify whether DXR analysis based on printouts of digital images is comparable to analysis of conventional images. The hand of a cadaver was X-rayed using varied parameters: 4-8 mAs, 40-52 kV, 90-130 cm FFD. Radiographs under standardised conditions were performed 10 times using a conventional machine (Philips Super 80 CP) and the printouts of a digital system (Digital Diagnost Philips Optimus) for the analysis of reproducibility. One image was scanned and analysed 10 times additionally for imaging reproducibility. Reliability error of the system for the imaging process using conventional radiographs-rays was 0.49% (standard conditions: 6 mAs, 40 kV, 1 m FFD), using printouts of digital images was 2.89% (4 mAs, 42 kV, 1 m FFD) and regarding the analysis process was 0.22%. BMD calculation is not affected by alterations in FFD (precision error 1.21%), mAs (0.83%) or film quality/brand (0.38%), but differs significantly depending on tube voltage (2.70%). The system was not able to analyse conventional images with tube voltages of 49/52 kV. DXR technology is stable with most of the tested parameters. Normative data should exclusively be used for calculations using similar tube voltage or correction factors. All other parameters had no significant influence on the BMD calculation. Reproducibility is high. For technical reasons it is not recommended to use the printouts of digital images for BMD determination. (orig.)

  5. Operation method of the X-ray equipment for the investigation of the ballooning of LWR-fuel rod simulators

    International Nuclear Information System (INIS)

    Mueller, S.; Thun, G.

    1977-06-01

    An X-Ray-equipment is described which has been selected and assembled for the recording of fuel rod simulator-deformations during a loss of coolant accident using a movie technique. With this method it is possible to observe and record the ballooning of the simulator under conditions similar to those in a reactor. Some typical pictures are shown which show that the quality is high enough to allow a quantitative evaluation of the ballooning as a function of time. (orig.) [de

  6. Management of radiodiagnostic equipment: Implementation of self-maintenance project of the conventional x-ray equipment of Hospital Universitario Clementino Fraga Filho - HUCFF-UFRJ

    International Nuclear Information System (INIS)

    Couto, N.F. do; Azevedo, A.C.P.; Koch, H.A.

    2001-01-01

    The project aims the implantation of a management program, for the maintenance of the conventional X-ray equipment at HUCFF. It has been implemented through the training of the electronic technicians who work at the Hospital. Essential courses were organized such as: Basics of Radioprotection, Radiographs Techniques, and Maintenance of equipment of X-Rays. Equipment: a library with the schemes of the equipment is being assembled in collaboration with UNICAMP. In order to manage the process, a software was created using the tools of the total quality for control of the maintenance. Preliminary tests: the equipment and their working conditions were evaluated, as well as the level of the employees' satisfaction with their use. The creation of a new routine for maintenance seeks to assist the demands of the new legislation in Brazil 5, and also reduce the costs to improve the quality of the images in the Radiodiagnostic Service. (author)

  7. The main tests for quality control in X-ray equipment of radiodiagnosis

    International Nuclear Information System (INIS)

    Ferreira, R.S.

    1988-01-01

    All aspects of the relation between patient, examination and diagnosis for controling the quality in radiodiagnosis are showed. The bundle collimation for decreasing the scattered radiation in patient and the systems for measuring the exposure time are described. The yield valuation and the tension for X-rays tube are also cited. (C.G.C.) [pt

  8. The performance of a prototype device designed to evaluate general quality parameters of X-ray equipment

    Science.gov (United States)

    Murata, C. H.; Fernandes, D. C.; Lavínia, N. C.; Caldas, L. V. E.; Pires, S. R.; Medeiros, R. B.

    2014-02-01

    The performance of radiological equipment can be assessed using non-invasive methods and portable instruments that can analyze an X-ray beam with just one exposure. These instruments use either an ionization chamber or a state solid detector (SSD) to evaluate X-ray beam parameters. In Brazil, no such instruments are currently being manufactured; consequently, these instruments come at a higher cost to users due to importation taxes. Additionally, quality control tests are time consuming and impose a high workload on the X-ray tubes when evaluating their performance parameters. The assessment of some parameters, such as the half-value layer (HVL), requires several exposures; however, this can be reduced by using a SSD that requires only a single exposure. One such SSD uses photodiodes designed for high X-ray sensitivity without the use of scintillation crystals. This sensitivity allows one electron-hole pair to be created per 3.63 eV of incident energy, resulting in extremely high and stable quantum efficiencies. These silicon photodiodes operate by absorbing photons and generating a flow of current that is proportional to the incident power. The aim of this study was to show the response of the solid sensor PIN RD100A detector in a multifunctional X-ray analysis system that is designed to evaluate the average peak voltage (kVp), exposure time, and HVL of radiological equipment. For this purpose, a prototype board that uses four SSDs was developed to measure kVp, exposure time, and HVL using a single exposure. The reproducibility and accuracy of the results were compared to that of different X-ray beam analysis instruments. The kVp reproducibility and accuracy results were 2% and 3%, respectively; the exposure time reproducibility and accuracy results were 2% and 1%, respectively; and the HVL accuracy was ±2%. The prototype's methodology was able to calculate these parameters with appropriate reproducibility and accuracy. Therefore, the prototype can be considered

  9. Patient dose simulations for scanning-beam digital x-ray tomosynthesis of the lungs

    International Nuclear Information System (INIS)

    Nelson, Geoff; Fahrig, Rebecca; Yoon, Sungwon; Krishna, Ganesh; Wilfley, Brian

    2013-01-01

    location. When tumor SNR is held constant (i.e., x-ray fluence is scaled appropriately), SBDX gives 2–10 times less dose than fluoroscopy for the same conditions within the typical range of patient locations. The relative position of the patient (as a percent of SDD) has a much more significant impact on dose than either SDD or patient position. The patient position providing the minimum dose for a given tumor SNR and SDD is approximately the same as the position of maximum tomographic angle.Conclusions: SBDX offers a significant dose advantage over currently used C-arm fluoroscopy. The patient location with lowest dose coincides with the location of maximum tomographic angle. In order to provide adequate space for the patient and for the pulmonologists’ equipment, a SDD of 100 cm is recommended

  10. Patient dose simulations for scanning-beam digital x-ray tomosynthesis of the lungs

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Geoff; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Yoon, Sungwon [Varian Medical Systems, Palo Alto, California 94304 (United States); Krishna, Ganesh [Palo Alto Medical Foundation, Mountain View, California 94040 (United States); Wilfley, Brian [Triple Ring Technologies, Inc., Newark, California 94560 (United States)

    2013-11-15

    location. When tumor SNR is held constant (i.e., x-ray fluence is scaled appropriately), SBDX gives 2–10 times less dose than fluoroscopy for the same conditions within the typical range of patient locations. The relative position of the patient (as a percent of SDD) has a much more significant impact on dose than either SDD or patient position. The patient position providing the minimum dose for a given tumor SNR and SDD is approximately the same as the position of maximum tomographic angle.Conclusions: SBDX offers a significant dose advantage over currently used C-arm fluoroscopy. The patient location with lowest dose coincides with the location of maximum tomographic angle. In order to provide adequate space for the patient and for the pulmonologists’ equipment, a SDD of 100 cm is recommended.

  11. Flash X-ray

    International Nuclear Information System (INIS)

    Sato, Eiichi

    2003-01-01

    Generation of quasi-monochromatic X-ray by production of weakly ionized line plasma (flash X-ray), high-speed imaging by the X-ray and high-contrast imaging by the characteristic X-ray absorption are described. The equipment for the X-ray is consisted from the high-voltage power supply and condenser, turbo molecular pump, and plasma X-ray tube. The tube has a long linear anticathode to produce the line plasma and flash X-ray at 20 kA current at maximum. X-ray spectrum is measured by the imaging plate equipped in the computed radiography system after diffracted by a LiF single crystal bender. Cu anticathode generates sharp peaks of K X-ray series. The tissue images are presented for vertebra, rabbit ear and heart, and dog heart by X-ray fluoroscopy with Ce anticathode. Generation of K-orbit characteristic X-ray with extremely low bremsstrahung is to be attempted for medical use. (N.I.)

  12. Ion chamber-electrometer measurement system for radiation protection tests in X-ray equipment for interventional procedures

    International Nuclear Information System (INIS)

    Bottaro, Marcio

    2012-01-01

    A new parallel plate ionization chamber with volume of 500 cc and an electrometer with digital interface for data acquisition, configuring an ion chamber electrometer measurement system, were developed to comply with specific requirements for compulsory radiation protection tests in interventional X-ray equipment. The ion chamber has as main characteristics: low cost, mechanical strength and response variation with beam energy of less than 5% in the 40 kV to 150 kV range. The electrometer has a high gain (5x10 8 V/A) transimpedance amplifier circuit and a data acquisition and control system developed in LabVIEW ® platform, including an integrated power supply for the ion chamber bias with adjustable DC voltage output from O to 1000 V and an air density correction system. Electric field calculations, laboratory measurements in standard beams and computational simulations of radiation interactions in chamber volume with Monte Carlo Method were employed in the elaborated methodology of the ion chamber development, which was tested and validated. It was also developed a simplified methodology for electrometer calibration that assures metrological trustworthiness of the measurement system. Tests for the system performance evaluation as environmental influence response, energy response, angular dependency, linearity and air kerma and air kerma rate dependency were performed according to international standards and requirements. Additionally, for a detailed evaluation of the developed ion chamber, simulations with various scattered radiation spectra were performed. The system was applied in leakage radiation, residual radiation and scattered radiation tests, being compared with other reference systems and validated for laboratorial test routine. (author)

  13. Evaluation of the composition of filters additional of equipment radiological intraoral by energy dispersive x-ray fluorescence (EDXRF)

    International Nuclear Information System (INIS)

    Franca, Alana Caroline; Torres, Catarina A.M.P.; Rocha, Ana S.S.; Deniak, Valeriy; Lara, Alessandro L.; Paschuk, Sergei A.; Fernandes, Angela; Westphalen, Fernando Henrique

    2013-01-01

    The need for high quality standards for radiographic images in order to make a diagnosis assertive, and being the additional filtration required in the intraoral X-ray equipment show the need of evaluating these filters. This study aims to examine the influence of the elemental composition of the filters of X-ray of dental intraoral equipment in the radiographic images quality. The filters analysis were performed by using the energy dispersive X-ray fluorescence method (EDXRF). Ten conventional filters were analysed. In this study, 33 radiographic exposures were performed using films: twenty radiographs in the incisor region and ten in the molar region, three exposures were also made in the same regions with same conditions without using filter. After radiographs development, optical density was measure and all radiographs were submitted to subjective evaluation by dental radiologists. Data obtained were correlated to effects evaluation of the elemental composition of all filters in the quality of the radiographic images. The elements found were: aluminum, cobalt, copper, sulfur, iron, manganese, titanium, zinc, and zirconium. The images obtained were identified in groups: Molars to 0.3 s; Incisors to 0.2 s; Incisors to 0.3 s, and for the group without filters. From the results obtained it was concluded that both unclear radiographs and ideal radiographs were produced by using filters of elementary common. Therefore, conventional filters evaluated were an acceptable option to produce quality images in dental radiology, despite differences in the composition of the alloys. (author)

  14. Evaluation of the composition of filters additional of equipment radiological intraoral by energy dispersive x-ray fluorescence (EDXRF)

    Energy Technology Data Exchange (ETDEWEB)

    Franca, Alana Caroline; Torres, Catarina A.M.P.; Rocha, Ana S.S.; Deniak, Valeriy; Lara, Alessandro L.; Paschuk, Sergei A., E-mail: alanacarolinef@gmail.com, E-mail: sergei@utfpr.edu.br [Universidade Tecnologica Federal do Parana (CPGEI/UTFPR), Curitiba, PR (Brazil). Programa de Pos-Graduacao em Engenharia Eletrica e Informatica Industrial; Fernandes, Angela; Westphalen, Fernando Henrique, E-mail: angelafernandes@ufpr.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Setor de Ciencias da Saude

    2013-07-01

    The need for high quality standards for radiographic images in order to make a diagnosis assertive, and being the additional filtration required in the intraoral X-ray equipment show the need of evaluating these filters. This study aims to examine the influence of the elemental composition of the filters of X-ray of dental intraoral equipment in the radiographic images quality. The filters analysis were performed by using the energy dispersive X-ray fluorescence method (EDXRF). Ten conventional filters were analysed. In this study, 33 radiographic exposures were performed using films: twenty radiographs in the incisor region and ten in the molar region, three exposures were also made in the same regions with same conditions without using filter. After radiographs development, optical density was measure and all radiographs were submitted to subjective evaluation by dental radiologists. Data obtained were correlated to effects evaluation of the elemental composition of all filters in the quality of the radiographic images. The elements found were: aluminum, cobalt, copper, sulfur, iron, manganese, titanium, zinc, and zirconium. The images obtained were identified in groups: Molars to 0.3 s; Incisors to 0.2 s; Incisors to 0.3 s, and for the group without filters. From the results obtained it was concluded that both unclear radiographs and ideal radiographs were produced by using filters of elementary common. Therefore, conventional filters evaluated were an acceptable option to produce quality images in dental radiology, despite differences in the composition of the alloys. (author)

  15. Method of estimating patient skin dose from dose displayed on medical X-ray equipment with flat panel detector

    International Nuclear Information System (INIS)

    Fukuda, Atsushi; Koshida, Kichiro; Togashi, Atsuhiko; Matsubara, Kousuke

    2004-01-01

    The International Electrotechnical Commission (IEC) has stipulated that medical X-ray equipment for interventional procedures must display radiation doses such as air kerma in free air at the interventional reference point and dose area product to establish radiation safety for patients (IEC 60601-2-43). However, it is necessary to estimate entrance skin dose for the patient from air kerma for an accurate risk assessment of radiation skin injury. To estimate entrance skin dose from displayed air kerma in free air at the interventional reference point, it is necessary to consider effective energy, the ratio of the mass-energy absorption coefficient for skin and air, and the backscatter factor. In addition, since automatic exposure control is installed in medical X-ray equipment with flat panel detectors, it is necessary to know the characteristics of control to estimate exposure dose. In order to calculate entrance skin dose under various conditions, we investigated clinical parameters such as tube voltage, tube current, pulse width, additional filter, and focal spot size, as functions of patient body size. We also measured the effective energy of X-ray exposure for the patient as a function of clinical parameter settings. We found that the conversion factor from air kerma in free air to entrance skin dose is about 1.4 for protection. (author)

  16. Interlaboratory comparison and accreditation in quality control testing of diagnostic X-ray equipment

    International Nuclear Information System (INIS)

    Kepler, K.; Vladimirov, A.; Servomaa, A.

    2005-01-01

    The Univ. of Tartu provides a quality control service to the majority of diagnostic X-ray departments in Estonia. Its methodology has been adopted from the IEC and other relevant standards. Recently the Testing Centre of the Univ. of Tartu was accredited on this methodology by ISO/IEC 17025. Besides the implementation of the quality management system, participation in interlaboratory comparison (ILC) was one of the prerequisites for the accreditation. Tests for estimating reproducibility of tube voltage and dose rate, accuracy of the voltage and accuracy of exposure time were carried out on a diagnostic X-ray unit in the Radiation and Nuclear Safety Authority in Helsinki. The measurement performance was judged by calculating deviation En normalised with respect to the stated uncertainties. En values for all tests were less than unity and by the common ILC criteria the testing performance could be considered as acceptable. (authors)

  17. A study on the digital image transfer application mass chest X-ray system up-grade

    International Nuclear Information System (INIS)

    Kim, Sun Chil; Park, Jong Sam; Lee, Jon Il

    2003-01-01

    By converting movable indirect mass chest X-ray devices for vehicles into digital systems and upgrading it to share information with the hospital's medical image information system, excellencies have been confirmed as a result of installing and running this type of system and are listed hereinafter. Upgrading analog systems, such as indirect mass chest X-ray devices dependent on printed film, to digital systems allows them to be run and managed much more efficiently, contributing to the increase in the stability and the efficiency of the system. Unlike existing images, communication based on DICOM standards allow images to be compatible with the hospital's outer and inner network PACS systems, extending the scope of the radiation departments information system. Assuming chest-exclusive indirect mass chest X-rays, a linked development of CAD (Computer Aided Diagnosis, Detector) becomes possible. By applying wireless Internet, Web-PACS for movable indirect mass chest X-ray devices for vehicles will become possible. Research in these fields must continue and if the superior image quality and convenience of digital systems are confirmed, I believe that the conversion of systems still dependent on analog images to modernized digital systems is a must

  18. Digital radiography - usability of experience in medical technology with fluorescent storage material for technical X-ray testing

    International Nuclear Information System (INIS)

    Mattis, A.; Winterberg, K.H.

    1992-01-01

    In nearly 100 years' development of X-ray technique, synergy effects between medical technology and non-destructive material testing (NDT) have repeatedly led to new applications. Thus digital radiography in medicine is a 'low dose' process introduced years ago which, by using a specially developed storage foil technique, offers extensive possibilities of application for NDT. (orig.) [de

  19. Metrological analysis of constancy tests in conventional medical X-ray equipment

    International Nuclear Information System (INIS)

    Alvarenga, Frederico L.; Oliveira, Paulo Marcio C.; Squair, Peterson L.; Soares, Carlos M.; Silva, Teogenes A. da

    2005-01-01

    Constancy tests in x-ray diagnostic machines should follow performance requirements with the aim to verify their safety and quality and to protect workers, patients and public members that are or may be exposed to ionizing radiation risks. In the Brazilian state of Minas Gerais, from 1999 to 2004, 110 radiometric and evaluation reports of x-ray machines were issued by accredited professionals. Most of the reports did not provide the estimation of the measurement uncertainty that should be part of the results; it means that there is a lack of metrological care in such reports which may cause difficulties to get a conclusive analysis. In this work, relevant sources of uncertainties were identified and estimated for the following tests carried out in a conventional x-ray machine: high voltage accuracy and reproducibility, air kerma rate repeatability and linearity and half-value layer determination. This work gives details on the methodology and the expanded and combined uncertainty values for each measuring procedure, which may be adopted as representative values for analysis of radiometric report. (author)

  20. 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 ...

  1. Characterizing X-ray detectors for prototype digital breast tomosynthesis systems

    International Nuclear Information System (INIS)

    Kim, Y.-S.; Park, H.-S.; Park, S.-J.; Choi, S.; Lee, H.; Kim, H.-J.; Lee, D.; Choi, Y.-W.

    2016-01-01

    The digital breast tomosynthesis (DBT) system is a newly developed 3-D imaging technique that overcomes the tissue superposition problems of conventional mammography. Therefore, it produces fewer false positives. In DBT system, several parameters are involved in image acquisition, including geometric components. A series of projections should be acquired at low exposure. This makes the system strongly dependent on the detector's characteristic performance. This study compares two types of x-ray detectors developed by the Korea Electrotechnology Research Institute (KERI). The first prototype DBT system has a CsI (Tl) scintillator/CMOS based flat panel digital detector (2923 MAM, Dexela Ltd.), with a pixel size of 0.0748 mm. The second uses a-Se based direct conversion full field detector (AXS 2430, analogic) with a pixel size of 0.085 mm. The geometry of both systems is same, with a focal spot 665.8 mm from the detector, and a center of rotation 33 mm above the detector surface. The systems were compared with regard to modulation transfer function (MTF), normalized noise power spectrum (NNPS), detective quantum efficiency (DQE) and a new metric, the relative object detectability (ROD). The ROD quantifies the relative performance of each detector at detecting specified objects. The system response function demonstrated excellent linearity (R 2 >0.99). The CMOS-based detector had a high sensitivity, while the Anrad detector had a large dynamic range. The higher MTF and noise power spectrum (NPS) values were measured using an Anrad detector. The maximum DQE value of the Dexela detector was higher than that of the Anrad detector with a low exposure level, considering one projection exposure for tomosynthesis. Overall, the Dexela detector performed better than did the Anrad detector with regard to the simulated Al wires, spheres, test objects of ROD with low exposure level. In this study, we compared the newly developed prototype DBT system with two different types

  2. kV x-ray dual digital tomosynthesis for image guided lung SBRT

    Science.gov (United States)

    Partain, Larry; Boyd, Douglas; Kim, Namho; Hernandez, Andrew; Daly, Megan; Boone, John

    2016-03-01

    Two simulated sets of digital tomosynthesis images of the lungs, each acquired at a 90 degree angle from the other, with 19 projection images used for each set and SART iterative reconstructed, gives dual tomosynthesis slice image quality approaching that of spiral CT, and with a data acquisition time that is 3% of that of cone beam CT. This fast kV acquisition, should allow near real time tracking of lung tumors in patients receiving SBRT, based on a novel TumoTrakTM multi-source X-ray tube design. Until this TumoTrakTM prototype is completed over the next year, its projected performance was simulated from the DRR images created from a spiral CT data set from a lung cancer patient. The resulting dual digital tomosynthesis reconstructed images of the lung tumor were exceptional and approached that of the gold standard Feldkamp CT reconstruction of breath hold, diagnostic, spiral, multirow, CT data. The relative dose at 46 mAs was less than 10% of what it would have been if the digital tomosynthesis had been done at the 472 mAs of the CT data set. This is for a 0.77 fps imaging rate sufficient to resolve respiratory motion in many free breathing patients during SBRT. Such image guidance could decrease the magnitudes of targeting error margins by as much as 20 mm or more in the craniocaudal direction for lower lobe lesions while markedly reducing dose to normal lung, heart and other critical structures. These initial results suggest a wide range of topics for future work.

  3. Development of a digital panoramic X-ray imaging system of adaptive image layers for dental applications

    International Nuclear Information System (INIS)

    Choi, S.I.; Park, Y.O.; Cho, H.S.; Oh, J.E.; Cho, H.M.; Hong, D.K.; Lee, M.S.; Yang, Y.J.; Je, U.K.; Kim, D.S.; Lee, H.K.

    2011-01-01

    As a continuation of our digital radiographic sensor R and D, we have developed a prototyped digital panoramic X-ray imaging system for dental applications. The imaging system consists of a slit-collimated X-ray generator with a 0.4 mm focal spot size and a 3.5 mm Al filtration, a linear-array typed CMOS imager with a 48x48 μm 2 pixel size and a 128 (in the scan direction)x3072 (in the vertical direction) pixel format, a series of microstep motors for the precise motion control of the imaging system, and the designed sequences for the motion control and pixel readout required to make a specific plane of interest (POI) to be focused. With the several test phantoms we designed, we obtained useful digital panoramic X-ray images by moving the X-ray generator and the CMOS imager along a continuously sliding rotational center. In this study, we demonstrated that the prototype system can be applicable to any shaped POI or multi-POIs simultaneously to be focused, provided that adequate sequences for motion control and pixel readout are designed. We expect that the imaging system will be useful for our ongoing applications of dental panoramic radiography and nondestructive testing.

  4. Study on Construction of a Medical X-Ray Direct Digital Radiography System and Hybrid Preprocessing Methods

    Directory of Open Access Journals (Sweden)

    Yong Ren

    2014-01-01

    Full Text Available We construct a medical X-ray direct digital radiography (DDR system based on a CCD (charge-coupled devices camera. For the original images captured from X-ray exposure, computer first executes image flat-field correction and image gamma correction, and then carries out image contrast enhancement. A hybrid image contrast enhancement algorithm which is based on sharp frequency localization-contourlet transform (SFL-CT and contrast limited adaptive histogram equalization (CLAHE, is proposed and verified by the clinical DDR images. Experimental results show that, for the medical X-ray DDR images, the proposed comprehensive preprocessing algorithm can not only greatly enhance the contrast and detail information, but also improve the resolution capability of DDR system.

  5. COMPARATIVE ASSESSMENT OF CHEMOTHERAPY EFFICIENCY MONITORING IN PULMONARY TUBERCULOSIS PATIENTS BY X-RAY EXAMINATION AND DIGITAL TOMOSYNTHESIS

    Directory of Open Access Journals (Sweden)

    M. M. Nikitin

    2016-01-01

    Full Text Available Goal of the study: to investigate the capabilities of digital tomosynthesis for monitoring of tuberculous changes in the lungs against the background of chemotherapy.Materials and methods. Results of chemotherapy efficiency monitored by X-ray in 55 respiratory tuberculosis patients were analyzed. Before treatment and in 2 months after chemotherapy start all patients had X-ray and DT with consequent analysis of the obtained data.Results. When monitoring the efficiency of drug therapy for pulmonary tuberculosis by DT some additional diagnostic data were obtained in 36,4% of cases compared to X-ray. The article describes specific features of tuberculous changes visualization of the chest with the follow-up of changes by DT; opportunities for X-ray monitoring efficiency enhancement in these patients are presented.Conclusions. DT provides more accurate evaluation of tuberculous changes in the lungs compared to X-ray, which greatly enhances understanding of the course of the disease and registration of the pulmonary disease cure. 

  6. Characterization of contaminated soils using a x-ray fluorescence equipment

    International Nuclear Information System (INIS)

    Quindos, L. S.; Fuente, I.; Sainz, C.; Queral, I.

    2006-01-01

    Fast and accurate material identification is required in many areas of the metal industry as well as surveillance of contaminated areas. The portable X-ray analyzer described in this paper consists of a hand-held probe and electronic unit. The system is configured with three excitation sources, such as ''241 Am, ''109Cd and ''55 Fe, which provides excellent performance for common elements to be controlled in contaminated soils. Data about measurements developed with this device in field as well as in the laboratory are shown in this paper. (Author)

  7. Evaluation of absorbed radiation dose rate in a didactic X-ray equipment

    International Nuclear Information System (INIS)

    Costa, Phelipe Amaral Ferreira; Perini, Ana Paula; Neves, Lucio Pereira

    2016-01-01

    This work was performed in order to create a new didactic experiment in the X-ray apparatus of PHYWE, where the saturation current was obtained through a free air ionization chamber. The values of saturation currents were obtained in two ways. Initially, the anodic DDP was kept constant and the anodic current was varied. In the second way, the anodic current was kept constant while the anodic DDP was varied. Therefore, we were able to evaluate the dependence of the absolved dose rate in relation to the DDP and the tube current. (author)

  8. Proposal for education. Education in radiation protection and equipment handling for personnel in X-ray applications that require permits

    International Nuclear Information System (INIS)

    1995-06-01

    Some stipulations are connected to the permits to use X-ray equipment for medical purposes, one of which is education of the personnel. At inspections SSI has found serious deficiencies in these educations. The quality of the education has large variations over the country, and at some hospitals it does not exist at all. In order to help the permit holders to increase the quality of the education, a proposal to a course has been worked out. The proposal contains advice on content and scope and disposition of the education for different categories of personnel

  9. Comparison of computed tomography, magnetic resonance imaging and conventional X-ray of the equine digit

    International Nuclear Information System (INIS)

    Kleiter, M.

    1996-10-01

    An anatomical study of the equine digit with computed tomography and magnetic resonance imaging was performed. In addition, the observed pathologic findings were compared with their diagnosticity in associated radiographs. Twenty isolated forelimbs were radiographed and compared with the according CT-images. From 19 isolated forelimbs and one hindlimb MR-images were taken using spinecho and overview gradient-echo sequences. The appearance of bone and soft tissue is described in various sectional positions. CT images allow excellent evaluation of bone tissue in cases in which the X-ray examination suffers from the superimposition of adjacent structures. Thus, in several cases of navicular disease additional findings were made using CT. An insertional desmopathy of the interosseus, a cartilagineous fetlock chip, a separation of the hoof wall and osteophytes of the distal phalanx were found with CT but not in the associated radiographs. MRI allows the specific diagnosis of joint-, ligament- and tendon diseases also in the hoof region. The possibility to evaluate the navicular region, the distal interphalangeal joint and the hoof matrix is of great diagnostic value. In one case of navicular d sease a defect of the flexor cortex with pannus formation could be diagnosed. In a case with chronical laminitis the separation of the epidermal lamellae and the growth of the scar horn were depicted. A tendinitis of the interosseus, fibrocartilage in the insertion of the deep digital flexor tendon, the interosseus and in the distal sesamoid ligaments are well documented. It is concluded that in some equine patients CT and MRI are indicated due to the substantial diagnostic information. (author)

  10. Optimization of x-ray spectra in digital mammography through Monte Carlo simulations.

    Science.gov (United States)

    Cunha, D M; Tomal, A; Poletti, M E

    2012-04-07

    In this work, a Monte Carlo code was used to investigate the performance of different x-ray spectra in digital mammography, through a figure of merit (FOM), defined as FOM = CNR²/(¯)D(g), with CNR being the contrast-to-noise ratio in image and [Formula: see text] being the average glandular dose. The FOM was studied for breasts with different thicknesses t (2 cm ≤ t ≤ 8 cm) and glandular contents (25%, 50% and 75% glandularity). The anode/filter combinations evaluated were those traditionally employed in mammography (Mo/Mo, Mo/Rh, Rh/Rh), and a W anode combined with Al or K-edge filters (Zr, Mo, Rh, Pd, Ag, Cd, Sn), for tube potentials between 22 and 34 kVp. Results show that the W anode combined with K-edge filters provides higher values of FOM for all breast thicknesses investigated. Nevertheless, the most suitable filter and tube potential depend on the breast thickness, and for t ≥ 6 cm, they also depend on breast glandularity. Particularly for thick and dense breasts, a W anode combined with K-edge filters can greatly improve the digital technique, with the values of FOM up to 200% greater than that obtained with the anode/filter combinations and tube potentials traditionally employed in mammography. For breasts with t < 4 cm, a general good performance was obtained with the W anode combined with 60 μm of the Mo filter at 24-25 kVp, while 60 μm of the Pd filter provided a general good performance at 24-26 kVp for t = 4 cm, and at 28-30 and 29-31 kVp for t = 6 and 8 cm, respectively.

  11. Energy resolution and throughput of a new real time digital pulse processing system for x-ray and gamma ray semiconductor detectors

    International Nuclear Information System (INIS)

    Abbene, L; Gerardi, G; Raso, G; Brai, M; Principato, F; Basile, S

    2013-01-01

    New generation spectroscopy systems have advanced towards digital pulse processing (DPP) approaches. DPP systems, based on direct digitizing and processing of detector signals, have recently been favoured over analog pulse processing electronics, ensuring higher flexibility, stability, lower dead time, higher throughput and better spectroscopic performance. In this work, we present the performance of a new real time DPP system for X-ray and gamma ray semiconductor detectors. The system is based on a commercial digitizer equipped with a custom DPP firmware, developed by our group, for on-line pulse shape and height analysis. X-ray and gamma ray spectra measurements with cadmium telluride (CdTe) and germanium (Ge) detectors, coupled to resistive-feedback preamplifiers, highlight the excellent performance of the system both at low and high rate environments (up to 800 kcps). A comparison with a conventional analog electronics showed the better high-rate capabilities of the digital approach, in terms of energy resolution and throughput. These results make the proposed DPP system a very attractive tool for both laboratory research and for the development of advanced detection systems for high-rate-resolution spectroscopic imaging, recently proposed in diagnostic medicine, industrial imaging and security screening

  12. Preparatory procedure and equipment for the European x-ray free electron laser cavity implementation

    Directory of Open Access Journals (Sweden)

    D. Reschke

    2010-07-01

    Full Text Available The European x-ray free electron laser is under construction at Deutsches Elektronen-Synchrotron (DESY. The electron beam energy of up to 17.5 GeV will be achieved by using superconducting accelerator technology. Final prototyping, industrialization, and new infrastructure are the actual challenges with respect to the accelerating cavities. This paper describes the preparation strategy optimized for the cavity preparation procedure in industry. For the industrial fabrication and preparation, several new hardware components have been already developed at DESY. The design and construction of a semiautomated rf-measurement machine for dumbbells and end groups are described. In a collaboration among FNAL, KEK, and DESY, an automatic cavity tuning machine has been designed and four machines are under construction. The functionality of these machines with special attention to safety aspects is described in this paper. A new high pressure rinsing system has been developed and is operational.

  13. X-rays detection system to obtain digital imagines for the study of artworks

    International Nuclear Information System (INIS)

    Bolanos, L.; Cabal, A. E.; Diaz, A.; Ramello, L.; Prino, F.; Giubellino, P.; Marzari-Chiesa, A.; Grybos, P.; Maj, P.; Gambaccini, M.; Petrucci, F.; Albertin, F.

    2008-01-01

    X-ray radiography plays an important role in the study of artworks. It particularly provides information on the origin, authenticity, painting technique, material conditions and its conservation history. This article describes a system based on semiconductor microstrip detector for obtaining X-ray images using the k-edge logarithmic substraction technique. The system has been characterized and the first images of its application for pigment detection are shown. (Author)

  14. Detector, collimator and real-time reconstructor for a new scanning-beam digital x-ray (SBDX) prototype.

    Science.gov (United States)

    Speidel, Michael A; Tomkowiak, Michael T; Raval, Amish N; Dunkerley, David A P; Slagowski, Jordan M; Kahn, Paul; Ku, Jamie; Funk, Tobias

    Scanning-beam digital x-ray (SBDX) is an inverse geometry fluoroscopy system for low dose cardiac imaging. The use of a narrow scanned x-ray beam in SBDX reduces detected x-ray scatter and improves dose efficiency, however the tight beam collimation also limits the maximum achievable x-ray fluence. To increase the fluence available for imaging, we have constructed a new SBDX prototype with a wider x-ray beam, larger-area detector, and new real-time image reconstructor. Imaging is performed with a scanning source that generates 40,328 narrow overlapping projections from 71 × 71 focal spot positions for every 1/15 s scan period. A high speed 2-mm thick CdTe photon counting detector was constructed with 320×160 elements and 10.6 cm × 5.3 cm area (full readout every 1.28 μs), providing an 86% increase in area over the previous SBDX prototype. A matching multihole collimator was fabricated from layers of tungsten, brass, and lead, and a multi-GPU reconstructor was assembled to reconstruct the stream of captured detector images into full field-of-view images in real time. Thirty-two tomosynthetic planes spaced by 5 mm plus a multiplane composite image are produced for each scan frame. Noise equivalent quanta on the new SBDX prototype measured 63%-71% higher than the previous prototype. X-ray scatter fraction was 3.9-7.8% when imaging 23.3-32.6 cm acrylic phantoms, versus 2.3-4.2% with the previous prototype. Coronary angiographic imaging at 15 frame/s was successfully performed on the new SBDX prototype, with live display of either a multiplane composite or single plane image.

  15. Local liquid velocity measurement of Trickle Bed Reactor using Digital Industrial X-ray Radiography

    Science.gov (United States)

    Mohd Salleh, Khairul Anuar

    Trickle Bed Reactors (TBRs) are fixed beds of particles in which both liquid and gas flow concurrently downward. They are widely used to produce not only fuels but also lubrication products. The measurement and the knowledge of local liquid velocities (VLL) in TBRs is less which is essential for advancing the understanding of its hydrodynamics and for validation computational fluid dynamics (CFD). Therefore, this work focused on developing a new, non-invasive, statistically reliable technique that can be used to measure local liquid velocity (VLL) in two-dimensions (2-D). This is performed by combining Digital Industrial X-ray Radiography (DIR) and Particle Tracking Velocimetry (PTV) techniques. This work also make possible the development of three-dimensional (3-D) VLL measurements that can be taken in TBRs. Measurements taken through both the combined and the novel technique, once validated, were found to be comparable to another technique (a two-point fiber optical probe) currently being developed at Missouri University of Science and Technology. The results from this study indicate that, for a gas-liquid-solid type bed, the measured VLL can have a maximum range that is between 35 and 51 times that of its superficial liquid velocity (VSL). Without the existence of gas, the measured VLL can have a maximum range that is between 4 and 4.7 times that of its VSL. At a higher V SL, the particle tracer was greatly distributed and became carried away by a high liquid flow rate. Neither the variance nor the range of measured VLL varied for any of the replications, confirming the reproducibility of the experimental measurements used, regardless of the VSL . The liquid's movement inside the pore was consistent with findings from previous studies that used various techniques.

  16. Distal root curvatures in mandibular molars: analysis using digital panoramic X-rays.

    Science.gov (United States)

    Fuentes, R; Farfán, C; Astete, N; Navarro, P; Arias, A

    2018-01-01

    The aim of this study was to describe the degree of curvature in distal roots in the first and second permanent mandibular molars in a Chilean patient sample. A cross-sectional descriptive study was conducted in which digital panoramic X-rays were analysed. Examinations of patients under 18 years, with signs of distortion or alteration in the contrast or the presence of pathologies that affected visualisation of the roots and pulp-chamber floor of the teeth to be analysed were excluded. Using the AutoCad software, an angle was drawn to represent the curve of the root in its different thirds, drawing lines inside the root canal from the pulp-chamber floor to the dental apex. Using the classic definition of dilaceration (root curvature > 90°), its prevalence was established. 412 teeth and roots were analysed, finding a dilaceration prevalence of 0.73% (n = 3). 84.72% of the roots presented some type of curvature. The middle third had the highest percentage of curvatures and the greatest average of angular curvature, whereas the cervical third was the straightest. No significant differences were found between the degree of curvature and the gender of the subjects, except for the apical third of tooth 3.6. The analysis of curvature by root third offers to the clinician a better perspective of the directional change of the roots and does not limit it to just the presence of curves in the apical third. The report of the angular degree of the curvatures, in addition to the prevalence of dilacerations, informs to the clinicians about the likelihood of finding difficulties when treating root canals. (Folia Morphol 2018; 77, 1: 131-137).

  17. On the technique of digital X-ray image processing, especially of digital substraction angiography

    International Nuclear Information System (INIS)

    Pfeiler, M.; Marhoff, P.

    1983-01-01

    Digital radiography, especially in the form of subtraction angiography, has found special consideration during the last two years as could be noted at many radiological conventions. Also a series of symposia was especially devoted to this subject. The extensive picture material shown at these conventions does not only document an important extension of the fields of application, but also an important increment in clinical and technical experience. Two pictures may represent many other examples: with a time lag of less than one year the improvement of objective and subjective image quality is easy to recognize. The principle and the technology of digital radiography were demonstrated at these conventions as well as in this magazine, and they also were discussed in detail; therefore a comprehensive review with only a few concepts necessary for defining the topic is sufficient here. Of the different imaging techniques, the fluorographic and the pulsed operation techniques are discussed, especially with regard to the storage method used. The definition of these concepts follows later. Special emphasis is put on some considerations of the signal-to-noise ratio that represents an essential criterion of the image quality. (orig.) [de

  18. Self-masking noise subtraction (SMNS) in digital X-ray tomosynthesis for the improvement of tomographic image quality

    International Nuclear Information System (INIS)

    Oh, J.E.; Cho, H.S.; Choi, S.I.; Park, Y.O.; Lee, M.S.; Cho, H.M.; Yang, Y.J.; Je, U.K.; Woo, T.H.; Lee, H.K.

    2011-01-01

    In this paper, we proposed a simple and effective reconstruction algorithm, the so-called self-masking noise subtraction (SMNS), in digital X-ray tomosynthesis to reduce the tomographic blur that is inherent in the conventional tomosynthesis based upon the shift-and-add (SAA) method. Using the SAA and the SMNS algorithms, we investigated the influence of tomographic parameters such as tomographic angle (θ) and angle step (Δθ) on the image quality, measuring the signal-difference-to-noise ratio (SDNR). Our simulation results show that the proposed algorithm seems to be efficient in reducing the tomographic blur and, thus, improving image sharpness. We expect the simulation results to be useful for the optimal design of a digital X-ray tomosynthesis system for our ongoing application of nondestructive testing (NDT).

  19. Design and theoretical investigation of a digital x-ray detector with large area and high spatial resolution

    Science.gov (United States)

    Gui, Jianbao; Guo, Jinchuan; Yang, Qinlao; Liu, Xin; Niu, Hanben

    2007-05-01

    X-ray phase contrast imaging is a promising new technology today, but the requirements of a digital detector with large area, high spatial resolution and high sensitivity bring forward a large challenge to researchers. This paper is related to the design and theoretical investigation of an x-ray direct conversion digital detector based on mercuric iodide photoconductive layer with the latent charge image readout by photoinduced discharge (PID). Mercuric iodide has been verified having a good imaging performance (high sensitivity, low dark current, low voltage operation and good lag characteristics) compared with the other competitive materials (α-Se,PbI II,CdTe,CdZnTe) and can be easily deposited on large substrates in the manner of polycrystalline. By use of line scanning laser beam and parallel multi-electrode readout make the system have high spatial resolution and fast readout speed suitable for instant general radiography and even rapid sequence radiography.

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

    Science.gov (United States)

    Sjöholm, B; Geijer, H; Persliden, J

    2005-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Arnav R. Mistry

    2014-01-01

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

  2. Development of a novel direct X-ray detector using photoinduced discharge (PID) readout for digital radiography

    Science.gov (United States)

    Heo, D.; Jeon, S.; Kim, J.-S.; Kim, R. K.; Cha, B. K.; Moon, B. J.; Yoon, J.

    2013-02-01

    We developed a novel direct X-ray detector using photoinduced discharge (PID) readout for digital radiography. The pixel resolution is 512 × 512 with 200 μm pixel and the overall active dimensions of the X-ray imaging panel is 10.24 cm × 10.24 cm. The detector consists of an X-ray absorption layer of amorphous selenium, a charge accumulation layer of metal, and a PID readout layer of amorphous silicon. In particular, the charge accumulation is pixelated because image charges generated by X-ray should be stored pixel by pixel. Here the image charges, or holes, are recombined with electrons generated by the PID method. We used a 405 nm laser diode and cylindrical lens to make a line beam source with a width of 50 μm for PID readout, which generates charges for each pixel lines during the scan. We obtained spatial frequencies of about 1.0 lp/mm for the X-direction (lateral direction) and 0.9 lp/mm for the Y-direction (scanning direction) at 50% modulation transfer function.

  3. Influence of X-ray scatter radiation on image quality in Digital Breast Tomosynthesis (DBT)

    International Nuclear Information System (INIS)

    Rodrigues, M.J.; Di Maria, S.; Baptista, M.; Belchior, A.; Afonso, J.; Venâncio, J.; Vaz, P.

    2017-01-01

    Digital breast tomosynthesis (DBT) is a quasi-three-dimensional imaging technique that was developed to solve the principal limitation of mammography, namely the overlapping tissue effect. This issue in standard mammography (SM) leads to two main problems: low sensitivity (difficulty to detect lesions) and low specificity (non-negligible percentage of false positives). Although DBT is now being introduced in clinical practice the features of this technique have not yet been fully and accurately assessed. Consequently, optimization studies in terms of choosing the most suitable parameters which maximize image quality according to the known limits of breast dosimetry are currently performing. In DBT, scatter radiation can lead to a loss of contrast and to an increase of image noise by reducing the signal-to-difference-noise ratio (SDNR) of a lesion. Moreover the use of an anti-scatter grid is a concern due to the low exposure of the photon flux available per projection. For this reason the main aim of this study was to analyze the influence of the scatter radiation on image quality and the dose delivered to the breast. In particular a detailed analysis of the scatter radiation on the optimal energy that maximizes the SDNR was performed for different monochromatic energies and voltages. To reach this objective the PenEasy Monte Carlo (MC) simulation tool imbedded in the general-purpose main program PENELOPE, was used. After a successful validation of the MC model with measurements, 2D projection images of primary, coherent and incoherent photons were obtained. For that, a homogeneous breast phantom (2, 4, 6, 8 cm) with 25%, 50% and 75% glandular compositions was used, including a 5 mm thick tumor. The images were generated for each monochromatic X-ray energies in the range from 16 keV to 32 keV. For each angular projection considered (25 angular projections covering an arc of 50°) the scatter-to-primary ratio (SPR), the mean glandular dose (MGD) and the signal

  4. X-ray radiation detectors of 'scintillator-photoreceiving device type' for industrial digital radiography with improved spatial resolution

    International Nuclear Information System (INIS)

    Ryzhykov, V.D.; Lysetska, O.K.; Opolonin, O.D.; Kozin, D.N.

    2003-01-01

    Main types of photo receivers used in X-ray digital radiography systems are luminescent screens that transfer the optical image onto charge collection instruments, which require cooling, and semiconductor silicon detectors, which limit the contrast sensitivity. We have developed and produced X-ray radiation detectors of 'scintillator-photoreceiving device' (S-PRD) type, which are integrally located on the inverse side of the photodiode (PD). The receiving-converting circuit (RCC) is designed for data conversion into digital form and their input into PC. Software is provided for RCC control and image visualization. Main advantages of these detectors are high industrial resolution (3-5 line pairs per mm), detecting activity up to 20 μm, controlled sensitivity, low weight and small size, imaging low (0.1-0.3 mrad) object dose in real time. In this work, main characteristics of 32-, 64- and 1024-channel detectors of S-PRD type were studied and compared for X-ray sensitivity with S-PD detectors. Images of the tested objects have been obtained. Recommendations are given on the use of different scintillation materials, depending upon the purpose of a digital radiographic system. The detectors operate in a broad energy range of ionizing radiation, hence the size of the controlled object is not limited. The system is sufficiently powerful to ensure frontal (through two walls) observation of pipelines with wall thickness up to 10 cm

  5. X-ray acquisition and electronic digital readout by charge coupled devices

    International Nuclear Information System (INIS)

    Cavailler, C.; Launspach, J.; Mens, A.; Sauneuf, R.

    1985-09-01

    X-ray imaging adapted to laser-matter interaction experiments consists in recording plasma images from its X-ray emission; these phenomena have between 100 ps and some nanoseconds duration. Investigation of the laser-driven plasma may require the formation and the detection of two-dimensional images formed by X-ray microscopes or spectrometers in the soft X-ray range (from about 50 eV to some keV). To reach that purpose, we have developed and tested two opto-electronic chains. The first one is built around a small image converter tube with a soft X-ray photocathode and P20 phosphor screen deposited on a fiber optic plate; the electronic image appearing on the screen is read by a C.C.D. working in the visible spectral range. The second one, designed to work below 100eV is realized with a very thin phosphor screen deposited on the fiber optic input of a visible microchannel image intensifier; the output image is then read by a C.C.D. in the same manner than previously

  6. Instrumental parameters' determination in a fluorescences X-ray Philips PW 1400 equipment

    International Nuclear Information System (INIS)

    Martinez, J.M.; Fasio, I.; Baronio, N.; Viola, M.

    1987-01-01

    The instrumental parameters of a Philips PW 1400 equipment wavelengths dispersive are determined; fundamentally, those related to the equipment's accuracy (stability at a very short, short and long term drift) as well as to those related to the detection system (dead time, detector's cleaning and detection limit). (S.M.) [es

  7. Systematic errors in digital volume correlation due to the self-heating effect of a laboratory x-ray CT scanner

    KAUST Repository

    Wang, B; Pan, B; Tao, Ran; Lubineau, Gilles

    2017-01-01

    The use of digital volume correlation (DVC) in combination with a laboratory x-ray computed tomography (CT) for full-field internal 3D deformation measurement of opaque materials has flourished in recent years. During x-ray tomographic imaging

  8. X-ray diagnostics for TFTR

    International Nuclear Information System (INIS)

    von Goeler, S.; Hill, K.W.; Bitter, M.

    1982-12-01

    A short description of the x-ray diagnostic preparation for the TFTR tokamak is given. The x-ray equipment consists of the limiter x-ray monitoring system, the soft x-ray pulse-height-analysis-system, the soft x-ray imaging system and the x-ray crystal spectrometer. Particular attention is given to the radiation protection of the x-ray systems from the neutron environment

  9. X-ray apparatus

    International Nuclear Information System (INIS)

    Bernstein, S.; Stagg, L.; Lambert, T.W.; Griswa, P.J.

    1976-01-01

    A patient support system for X-ray equipment in arteriographic studies of the heart is described in detail. The support system has been designed to overcome many of the practical problems encountered in using previous types of arteriographic X-ray equipment. The support system is capable of horizontal movement and, by a series of shafts attached to the main support system, the X-ray source and image intensifier or detector may be rotated through the same angle. The system is highly flexible and details are given of several possible operational modes. (U.K.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-08-15

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

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

    International Nuclear Information System (INIS)

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

    2014-08-01

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

  12. X-ray sources

    International Nuclear Information System (INIS)

    Masswig, I.

    1986-01-01

    The tkb market survey comparatively evaluates the X-ray sources and replacement tubes for stationary equipment currently available on the German market. It lists the equipment parameters of 235 commercially available X-ray sources and their replacement tubes and gives the criteria for purchase decisions. The survey has been completed with December 1985, and offers good information concerning medical and technical aspects as well as those of safety and maintenance. (orig.) [de

  13. New digital fluorography system for X-ray angiography, super DF series

    International Nuclear Information System (INIS)

    Taniguchi, Yoshio; Fujii, Senzo; Maehama, Tomio

    1994-01-01

    The digital fluorography system is designed for the digital acquisition and processing of angiographic images. Since angiography is a radiographic technique which is occasionally performed during catheterization, the system is required to be highly reliable and efficient in operation. In addition, new demand has arisen in the medical equipment market with the increasing popularity of angioplasty. The DFP-1000A/2000A has been developed as a new system to respond to these requirements of users. The new system supplies high-speed and high-resolution diagnostic images using a TV camera with 1,024-matrix CCD and real-time image processing technology. This paper describes the clinical demand and new technology incorporated in the new system. (author)

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  15. Digital fluorography system for X-ray angiography, DFP-60A

    International Nuclear Information System (INIS)

    Oe, Mitsuo; Masuda, Ikuji; Fujii, Senzo

    1990-01-01

    The digital fluorography system is designed for acquisition and processing of angiographic images. Since angiography is a radiographic technique which is occasionally performed during catheterization, the system is required to be highly reliable and efficient in operation. In addition, a new demand has arisen in the medical equipment market with the increasing popularity of angioplasty (reconstruction of an injured blood vessel with a catheter). The DFP-60A has been developed as a new system to respond to this requirement of users. This paper describes the development concept and features of the new system. (author)

  16. Research summary: experiments which use the X-ray charge changed beam apparatus and equipment development

    International Nuclear Information System (INIS)

    Shafroth, S.M.; Clark, M.W.; Swenson, J.K.; Anthony, J.M.; Reed, M.

    1985-01-01

    Several atomic physics experiments are briefly described. These include resonant and nonresonant transfer excitation, simultaneous excitation and ionization, bare H-like and He-like beam experiments and single and double electron capture. Equipment development is also discussed

  17. Influence of X-ray scatter radiation on image quality in Digital Breast Tomosynthesis (DBT)

    Science.gov (United States)

    Rodrigues, M. J.; Di Maria, S.; Baptista, M.; Belchior, A.; Afonso, J.; Venâncio, J.; Vaz, P.

    2017-11-01

    Digital breast tomosynthesis (DBT) is a quasi-three-dimensional imaging technique that was developed to solve the principal limitation of mammography, namely the overlapping tissue effect. This issue in standard mammography (SM) leads to two main problems: low sensitivity (difficulty to detect lesions) and low specificity (non-negligible percentage of false positives). Although DBT is now being introduced in clinical practice the features of this technique have not yet been fully and accurately assessed. Consequently, optimization studies in terms of choosing the most suitable parameters which maximize image quality according to the known limits of breast dosimetry are currently performing. In DBT, scatter radiation can lead to a loss of contrast and to an increase of image noise by reducing the signal-to-difference-noise ratio (SDNR) of a lesion. Moreover the use of an anti-scatter grid is a concern due to the low exposure of the photon flux available per projection. For this reason the main aim of this study was to analyze the influence of the scatter radiation on image quality and the dose delivered to the breast. In particular a detailed analysis of the scatter radiation on the optimal energy that maximizes the SDNR was performed for different monochromatic energies and voltages. To reach this objective the PenEasy Monte Carlo (MC) simulation tool imbedded in the general-purpose main program PENELOPE, was used. After a successful validation of the MC model with measurements, 2D projection images of primary, coherent and incoherent photons were obtained. For that, a homogeneous breast phantom (2, 4, 6, 8 cm) with 25%, 50% and 75% glandular compositions was used, including a 5 mm thick tumor. The images were generated for each monochromatic X-ray energies in the range from 16 keV to 32 keV. For each angular projection considered (25 angular projections covering an arc of 50°) the scatter-to-primary ratio (SPR), the mean glandular dose (MGD) and the signal

  18. Structural analysis of jewelry from the Moche tomb of the `lady of Cao' by X-ray digital radiography

    Science.gov (United States)

    Azeredo, S. R.; Cesareo, R.; Franco, R.; Fernandez, A.; Bustamante, A.; Lopes, R. T.

    2018-04-01

    Nose ornaments from the tomb of the `Lady of Cao', a mummified woman representative of the Moche culture and dated to the third-or-fourth century AD, were analyzed by X-ray digital radiography. These spectacular gold and silver jewels are some of the most sophisticated metalworking ever produced in ancient America. The Mochecivilization flourished along the north coast of present-day Peru, between the Andes and the Pacific Ocean, approximately between 100 and 600 AD. The Moche were very sophisticated artisans and metal smiths, being considered the finest producers of jewels and artifacts of the region. A portable X-ray digital radiography (XDR) system consisting of a flat panel detector with high resolution image and a mini X-ray tube was used for the structural analysis of the Moche jewels aiming at inferring different joining methods of the silver-gold sheets. The radiographic analysis showed some differences in the joint of the silver-and-gold sheets. Presence of filler material and adhesive for joining the silver-and-gold sheets was visible as well as silver-gold junctions without filler material (or with a material invisible in radiography). Furthermore, the technique demonstrated the advantage of using a portable XDR micro system when the sample cannot be brought to the laboratory.

  19. A digital x-ray imaging MWPC detector system for precision absorptiometry

    International Nuclear Information System (INIS)

    Batemen, J.E.; Connolly, J.F.; Glasgow, W.

    1977-11-01

    An X-ray absorptiometric imaging system (based on a xenon-filled multiwire proportional counter) has been developed with high counting rate capability, good spatial resolution and linear mass response, aimed at permitting bone mass measurements to be made in the peripheral skeleton with precision approaching 1%. The system is described and preliminary results on test phantoms are presented. (author)

  20. Monte Carlo derivation of filtered tungsten anode X-ray spectra for dose computation in digital mammography*

    Science.gov (United States)

    Paixão, Lucas; Oliveira, Bruno Beraldo; Viloria, Carolina; de Oliveira, Marcio Alves; Teixeira, Maria Helena Araújo; Nogueira, Maria do Socorro

    2015-01-01

    Objective Derive filtered tungsten X-ray spectra used in digital mammography systems by means of Monte Carlo simulations. Materials and Methods Filtered spectra for rhodium filter were obtained for tube potentials between 26 and 32 kV. The half-value layer (HVL) of simulated filtered spectra were compared with those obtained experimentally with a solid state detector Unfors model 8202031-H Xi R/F & MAM Detector Platinum and 8201023-C Xi Base unit Platinum Plus w mAs in a Hologic Selenia Dimensions system using a direct radiography mode. Results Calculated HVL values showed good agreement as compared with those obtained experimentally. The greatest relative difference between the Monte Carlo calculated HVL values and experimental HVL values was 4%. Conclusion The results show that the filtered tungsten anode X-ray spectra and the EGSnrc Monte Carlo code can be used for mean glandular dose determination in mammography. PMID:26811553

  1. Monte Carlo derivation of filtered tungsten anode X-ray spectra for dose computation in digital mammography

    Directory of Open Access Journals (Sweden)

    Lucas Paixão

    2015-12-01

    Full Text Available Abstract Objective: Derive filtered tungsten X-ray spectra used in digital mammography systems by means of Monte Carlo simulations. Materials and Methods: Filtered spectra for rhodium filter were obtained for tube potentials between 26 and 32 kV. The half-value layer (HVL of simulated filtered spectra were compared with those obtained experimentally with a solid state detector Unfors model 8202031-H Xi R/F & MAM Detector Platinum and 8201023-C Xi Base unit Platinum Plus w mAs in a Hologic Selenia Dimensions system using a direct radiography mode. Results: Calculated HVL values showed good agreement as compared with those obtained experimentally. The greatest relative difference between the Monte Carlo calculated HVL values and experimental HVL values was 4%. Conclusion: The results show that the filtered tungsten anode X-ray spectra and the EGSnrc Monte Carlo code can be used for mean glandular dose determination in mammography.

  2. A Study of Equipment Accuracy and Test Precision in Dual Energy X-ray Absorptiometry

    International Nuclear Information System (INIS)

    Dong, Kyung Rae; Kim, Ho Sung; Jung, Woon Kwan

    2008-01-01

    Because there is a difference depending on the environment as for an inspection equipment the important part of bone density scan and the precision/accuracy of a tester, the management of quality must be made systematically. The equipment failure caused by overload effect due to the aged equipment and the increase of a patient was made frequently. Thus, the replacement of equipment and additional purchases of new bone density equipment caused a compatibility problem in tracking patients. This study wants to know whether the clinical changes of patient's bone density can be accurately and precisely reflected when used it compatibility like the existing equipment after equipment replacement and expansion. Two equipment of GE Lunar Prodigy Advance(P1 and P2) and the Phantom HOLOGIC Spine Road(HSP) were used to measure equipment precision. Each device scans 20 times so that precision data was acquired from the phantom(Group 1). The precision of a tester was measured by shooting twice the same patient, every 15 members from each of the target equipment in 120 women(average age 48.78, 20-60 years old)(Group 2). In addition, the measurement of the precision of a tester and the cross-calibration data were made by scanning 20 times in each of the equipment using HSP, based on the data obtained from the management of quality using phantom(ASP) every morning (Group 3). The same patient was shot only once in one equipment alternately to make the measurement of the precision of a tester and the cross-calibration data in 120 women(average age 48.78, 20-60 years old)(Group 4). It is steady equipment according to daily Q.C Data with 0.996 g/cm 2 , change value(%CV) 0.08. The meanSD and a %CV price are ALP in Group 1(P1 : , , P2 : , %CV=0.192). The mean±SD and a %CV price are P1 : 1.064±0.002 g/cm 2 , %CV=0.190 g/cm 2 , P2 : 1.061±0.003 g/cm 3 , %CV=0.163 in Group 2. The average error±2SD and %CV are P1 - (spine: 0.001±0.013 g/cm 2 , %CV=0.94, Femur: 0.001±0.019 g/cm 2 , %CV

  3. A Study of Equipment Accuracy and Test Precision in Dual Energy X-ray Absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Kyung Rae [Dept. of Radiological Technology, Gwangju Health College, Gwangju (Korea, Republic of); Kim, Ho Sung [Dept. of Nuclear Medicine, Asan Medical Center, Seoul (Korea, Republic of); Jung, Woon Kwan [Dept. of Nuclear Energy Technology, Chosun University, Gwangju (Korea, Republic of)

    2008-03-15

    Because there is a difference depending on the environment as for an inspection equipment the important part of bone density scan and the precision/accuracy of a tester, the management of quality must be made systematically. The equipment failure caused by overload effect due to the aged equipment and the increase of a patient was made frequently. Thus, the replacement of equipment and additional purchases of new bone density equipment caused a compatibility problem in tracking patients. This study wants to know whether the clinical changes of patient's bone density can be accurately and precisely reflected when used it compatibility like the existing equipment after equipment replacement and expansion. Two equipment of GE Lunar Prodigy Advance(P1 and P2) and the Phantom HOLOGIC Spine Road(HSP) were used to measure equipment precision. Each device scans 20 times so that precision data was acquired from the phantom(Group 1). The precision of a tester was measured by shooting twice the same patient, every 15 members from each of the target equipment in 120 women(average age 48.78, 20-60 years old)(Group 2). In addition, the measurement of the precision of a tester and the cross-calibration data were made by scanning 20 times in each of the equipment using HSP, based on the data obtained from the management of quality using phantom(ASP) every morning (Group 3). The same patient was shot only once in one equipment alternately to make the measurement of the precision of a tester and the cross-calibration data in 120 women(average age 48.78, 20-60 years old)(Group 4). It is steady equipment according to daily Q.C Data with 0.996 g/cm{sup 2}, change value(%CV) 0.08. The meanSD and a %CV price are ALP in Group 1(P1 : , , P2 : , %CV=0.192). The mean{+-}SD and a %CV price are P1 : 1.064{+-}0.002 g/cm{sup 2}, %CV=0.190 g/cm{sup 2}, P2 : 1.061{+-}0.003 g/cm{sup 3}, %CV=0.163 in Group 2. The average error{+-}2SD and %CV are P1 - (spine: 0.001{+-}0.013 g/cm{sup 2}, %CV=0

  4. Comparing of the yield curve of the pediatric X-ray equipment using thermoluminescent dosimeters and cylindrical ionization chamber

    International Nuclear Information System (INIS)

    Filipov, Danielle; Schelin, Hugo R.; Tilly Junior, Joao G.

    2014-01-01

    The determination of the yield curve of a radiographic equipment should be realized once a year, or when the unit be serviced. Besides being a requirement of ANVISA, through this test is possible to determine the incident air kerma (at a given point in the center of the beam) - INAK. Based on these concepts, the main objective of this work is the comparison of yield curves of the pediatric X-ray apparatus using two different detectors: one cylindrical ionization chamber and thermoluminescent dosimeters type LiF: Mg, Cu, P, as per protocol RLA / 9/057 IAEA. Then the equation of the yield curve (generated by each detector) was used to determine the INAK of 10 pediatric examinations, performed on this equipment. After the process of calibration of both detectors, they were placed side by side at a focus of the tube equipment for determining the performance of the same curve. Finally, using the curves generated by two detectors, INAK values of the 10 tests were calculated (from the kVp values, and mAs focus-patient of each exams), generating difference values at most 5%. As a conclusion, it can be said that the TLD lithium fluoride doped with Mg, Cu and P and the cylindrical ionization chambers may be used satisfactorily to determine the yield curve, whether as quality control or dosimetry

  5. Digital twin image elimination in soft x-ray in-line holography

    International Nuclear Information System (INIS)

    Koren, G.; Joyeux, D.

    1993-01-01

    In-line holography is attractive for X-ray microscopy due to its recording simplicity. A drawback of this method is the superposition of the virtual and real images, in which structures and details can be modified or lost. This superposition effectively limits the application of in-line holography to X-ray microscopy. The authors present an iterative constrained algorithm for twin image elimination from Gabor holograms of finite support objects. It is based in the different spatial extent of both images, together with a finite support constraint. The conditions under which the algorithm is applicable will be presented, together with an alternative Monte Carlo method for holograms of complex objects recorded in the shadow region

  6. Large area CMOS active pixel sensor x-ray imager for digital breast tomosynthesis: Analysis, modeling, and characterization.

    Science.gov (United States)

    Zhao, Chumin; Kanicki, Jerzy; Konstantinidis, Anastasios C; Patel, Tushita

    2015-11-01

    Large area x-ray imagers based on complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been proposed for various medical imaging applications including digital breast tomosynthesis (DBT). The low electronic noise (50-300 e-) of CMOS APS x-ray imagers provides a possible route to shrink the pixel pitch to smaller than 75 μm for microcalcification detection and possible reduction of the DBT mean glandular dose (MGD). In this study, imaging performance of a large area (29×23 cm2) CMOS APS x-ray imager [Dexela 2923 MAM (PerkinElmer, London)] with a pixel pitch of 75 μm was characterized and modeled. The authors developed a cascaded system model for CMOS APS x-ray imagers using both a broadband x-ray radiation and monochromatic synchrotron radiation. The experimental data including modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE) were theoretically described using the proposed cascaded system model with satisfactory consistency to experimental results. Both high full well and low full well (LFW) modes of the Dexela 2923 MAM CMOS APS x-ray imager were characterized and modeled. The cascaded system analysis results were further used to extract the contrast-to-noise ratio (CNR) for microcalcifications with sizes of 165-400 μm at various MGDs. The impact of electronic noise on CNR was also evaluated. The LFW mode shows better DQE at low air kerma (Ka<10 μGy) and should be used for DBT. At current DBT applications, air kerma (Ka∼10 μGy, broadband radiation of 28 kVp), DQE of more than 0.7 and ∼0.3 was achieved using the LFW mode at spatial frequency of 0.5 line pairs per millimeter (lp/mm) and Nyquist frequency ∼6.7 lp/mm, respectively. It is shown that microcalcifications of 165-400 μm in size can be resolved using a MGD range of 0.3-1 mGy, respectively. In comparison to a General Electric GEN2 prototype DBT system (at MGD of 2.5 mGy), an increased CNR (by ∼10) for

  7. Large area CMOS active pixel sensor x-ray imager for digital breast tomosynthesis: Analysis, modeling, and characterization

    International Nuclear Information System (INIS)

    Zhao, Chumin; Kanicki, Jerzy; Konstantinidis, Anastasios C.; Patel, Tushita

    2015-01-01

    Purpose: Large area x-ray imagers based on complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been proposed for various medical imaging applications including digital breast tomosynthesis (DBT). The low electronic noise (50–300 e − ) of CMOS APS x-ray imagers provides a possible route to shrink the pixel pitch to smaller than 75 μm for microcalcification detection and possible reduction of the DBT mean glandular dose (MGD). Methods: In this study, imaging performance of a large area (29 × 23 cm 2 ) CMOS APS x-ray imager [Dexela 2923 MAM (PerkinElmer, London)] with a pixel pitch of 75 μm was characterized and modeled. The authors developed a cascaded system model for CMOS APS x-ray imagers using both a broadband x-ray radiation and monochromatic synchrotron radiation. The experimental data including modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE) were theoretically described using the proposed cascaded system model with satisfactory consistency to experimental results. Both high full well and low full well (LFW) modes of the Dexela 2923 MAM CMOS APS x-ray imager were characterized and modeled. The cascaded system analysis results were further used to extract the contrast-to-noise ratio (CNR) for microcalcifications with sizes of 165–400 μm at various MGDs. The impact of electronic noise on CNR was also evaluated. Results: The LFW mode shows better DQE at low air kerma (K a < 10 μGy) and should be used for DBT. At current DBT applications, air kerma (K a ∼ 10 μGy, broadband radiation of 28 kVp), DQE of more than 0.7 and ∼0.3 was achieved using the LFW mode at spatial frequency of 0.5 line pairs per millimeter (lp/mm) and Nyquist frequency ∼6.7 lp/mm, respectively. It is shown that microcalcifications of 165–400 μm in size can be resolved using a MGD range of 0.3–1 mGy, respectively. In comparison to a General Electric GEN2 prototype DBT system (at MGD of 2.5 m

  8. Large area CMOS active pixel sensor x-ray imager for digital breast tomosynthesis: Analysis, modeling, and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chumin; Kanicki, Jerzy, E-mail: kanicki@eecs.umich.edu [Solid-State Electronics Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Konstantinidis, Anastasios C. [Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom and Diagnostic Radiology and Radiation Protection, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester M20 4BX (United Kingdom); Patel, Tushita [Department of Physics, University of Virginia, Charlottesville, Virginia 22908 (United States)

    2015-11-15

    Purpose: Large area x-ray imagers based on complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been proposed for various medical imaging applications including digital breast tomosynthesis (DBT). The low electronic noise (50–300 e{sup −}) of CMOS APS x-ray imagers provides a possible route to shrink the pixel pitch to smaller than 75 μm for microcalcification detection and possible reduction of the DBT mean glandular dose (MGD). Methods: In this study, imaging performance of a large area (29 × 23 cm{sup 2}) CMOS APS x-ray imager [Dexela 2923 MAM (PerkinElmer, London)] with a pixel pitch of 75 μm was characterized and modeled. The authors developed a cascaded system model for CMOS APS x-ray imagers using both a broadband x-ray radiation and monochromatic synchrotron radiation. The experimental data including modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE) were theoretically described using the proposed cascaded system model with satisfactory consistency to experimental results. Both high full well and low full well (LFW) modes of the Dexela 2923 MAM CMOS APS x-ray imager were characterized and modeled. The cascaded system analysis results were further used to extract the contrast-to-noise ratio (CNR) for microcalcifications with sizes of 165–400 μm at various MGDs. The impact of electronic noise on CNR was also evaluated. Results: The LFW mode shows better DQE at low air kerma (K{sub a} < 10 μGy) and should be used for DBT. At current DBT applications, air kerma (K{sub a} ∼ 10 μGy, broadband radiation of 28 kVp), DQE of more than 0.7 and ∼0.3 was achieved using the LFW mode at spatial frequency of 0.5 line pairs per millimeter (lp/mm) and Nyquist frequency ∼6.7 lp/mm, respectively. It is shown that microcalcifications of 165–400 μm in size can be resolved using a MGD range of 0.3–1 mGy, respectively. In comparison to a General Electric GEN2 prototype DBT system (at

  9. Geometric calibration of a stationary digital breast tomosynthesis system based on distributed carbon nanotube X-ray source arrays.

    Directory of Open Access Journals (Sweden)

    Changhui Jiang

    Full Text Available Stationary digital breast tomosynthesis (sDBT with distributed X-ray sources based on carbon nanotube (CNT field emission cathodes has been recently proposed as an approach that can prevent motion blur produced by traditional DBT systems. In this paper, we simulate a geometric calibration method based on a proposed multi-source CNT X-ray sDBT system. This method is a projection matrix-based approach with seven geometric parameters, all of which can be obtained from only one projection datum of the phantom. To our knowledge, this study reports the first application of this approach in a CNT-based multi-beam X-ray sDBT system. The simulation results showed that the extracted geometric parameters from the calculated projection matrix are extremely close to the input values and that the proposed method is effective and reliable for a square sDBT system. In addition, a traditional cone-beam computed tomography (CT system was also simulated, and the uncalibrated and calibrated geometric parameters were used in image reconstruction based on the filtered back-projection (FBP method. The results indicated that the images reconstructed with calibrated geometric parameters have fewer artifacts and are closer to the reference image. All the simulation tests showed that this geometric calibration method is optimized for sDBT systems but can also be applied to other application-specific CT imaging systems.

  10. Suppression of high-density artefacts in x-ray CT images using temporal digital subtraction with application to cryotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Baissalov, R.; Sandison, G.A.; Rewcastle, J.C. [Department of Medical Physics, Tom Baker Cancer Center, Calgary, Canada, T2N 4N2 2 Department of Physics and Astronomy, University of Calgary, Calgary T2N 2N4 (Canada); Donnelly, B.J. [Department of Surgery, Tom Baker Cancer Center, Calgary, Canada, T2N 4N2 4 Department of Surgery, Foothills Hospital, Calgary T2N 2T7 (Canada); Saliken, J.C. [Department of Surgery, Tom Baker Cancer Center, Calgary T2N 4N2 (Canada); Department of Diagnostic Imaging, Foothills Hospital, Calgary T2N 2T7 (Canada); McKinnon, J.G. [Department of Surgery, Foothills Hospital, Calgary T2N 2T7 (Canada); Muldrew, K. [Department of Surgery, Faculty of Medicine, University of Calgary, Calgary T2N 2T7 (Canada)

    2000-05-01

    Image guidance in cryotherapy is usually performed using ultrasound. Although not currently in routine clinical use, x-ray CT imaging is an alternative means of guidance that can display the full 3D structure of the iceball, including frozen and unfrozen regions. However, the quality of x-ray CT images is compromised by the presence of high-density streak artefacts. To suppress these artefacts we applied temporal digital subtraction (TDS). This TDS method has the added advantage of improving the grey-scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high-density artefacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced artefact content. Thus TDS can be used to significantly suppress or eliminate high-density CT streak artefacts without reducing the metallic content of the cryoprobes. In vivo study needs to be conducted to establish the utility of this TDS procedure for CT assisted prostate or liver cryotherapy. Applying TDS in x-ray CT guided cryotherapy will facilitate estimation of the number and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent. (author)

  11. Suppression of high-density artefacts in x-ray CT images using temporal digital subtraction with application to cryotherapy

    International Nuclear Information System (INIS)

    Baissalov, R.; Sandison, G.A.; Rewcastle, J.C.; Donnelly, B.J.; Saliken, J.C.; McKinnon, J.G.; Muldrew, K.

    2000-01-01

    Image guidance in cryotherapy is usually performed using ultrasound. Although not currently in routine clinical use, x-ray CT imaging is an alternative means of guidance that can display the full 3D structure of the iceball, including frozen and unfrozen regions. However, the quality of x-ray CT images is compromised by the presence of high-density streak artefacts. To suppress these artefacts we applied temporal digital subtraction (TDS). This TDS method has the added advantage of improving the grey-scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high-density artefacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced artefact content. Thus TDS can be used to significantly suppress or eliminate high-density CT streak artefacts without reducing the metallic content of the cryoprobes. In vivo study needs to be conducted to establish the utility of this TDS procedure for CT assisted prostate or liver cryotherapy. Applying TDS in x-ray CT guided cryotherapy will facilitate estimation of the number and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent. (author)

  12. Geometric calibration of a stationary digital breast tomosynthesis system based on distributed carbon nanotube X-ray source arrays.

    Science.gov (United States)

    Jiang, Changhui; Zhang, Na; Gao, Juan; Hu, Zhanli

    2017-01-01

    Stationary digital breast tomosynthesis (sDBT) with distributed X-ray sources based on carbon nanotube (CNT) field emission cathodes has been recently proposed as an approach that can prevent motion blur produced by traditional DBT systems. In this paper, we simulate a geometric calibration method based on a proposed multi-source CNT X-ray sDBT system. This method is a projection matrix-based approach with seven geometric parameters, all of which can be obtained from only one projection datum of the phantom. To our knowledge, this study reports the first application of this approach in a CNT-based multi-beam X-ray sDBT system. The simulation results showed that the extracted geometric parameters from the calculated projection matrix are extremely close to the input values and that the proposed method is effective and reliable for a square sDBT system. In addition, a traditional cone-beam computed tomography (CT) system was also simulated, and the uncalibrated and calibrated geometric parameters were used in image reconstruction based on the filtered back-projection (FBP) method. The results indicated that the images reconstructed with calibrated geometric parameters have fewer artifacts and are closer to the reference image. All the simulation tests showed that this geometric calibration method is optimized for sDBT systems but can also be applied to other application-specific CT imaging systems.

  13. Objective masurement of image quality in fluoroscopic x-ray equipment FluoroQuality

    CERN Document Server

    Tapiovaara, M

    2003-01-01

    The report describes FluoroQuality, a computer program that is developed in STUK and used for measuring the image quality in medical fluoroscopic equipment. The method is based on the statistical decision theory (SDT) and the main measurement result is given in terms of the accumulation rate of the signal-to-noise ratio squared (SNR sup 2 sub r sub a sub t sub e). In addition to this quantity several other quantities are measured. These quantities include the SNR of single image frames, the spatio-temporal noise power spectrum and the temporal lag. The measurement method can be used, for example, for specifying the image quality in fluoroscopic images, for optimising the image quality and dose rate in fluoroscopy and for quality control of fluoroscopic equipment. The theory behind the measurement method is reviewed and the measurement of the various quantities is explained. An example of using the method for optimising a specified fluoroscopic procedure is given. The User's Manual of the program is included a...

  14. THE X-RAY PROPERTIES OF THE OPTICALLY BRIGHTEST MINI-BAL QUASARS FROM THE SLOAN DIGITAL SKY SURVEY

    International Nuclear Information System (INIS)

    Wu Jianfeng; Brandt, W. N.; Comins, M. L.; Garmire, Gordon P.; Schneider, Donald P.; Gibson, Robert R.; Shemmer, Ohad

    2010-01-01

    We have compiled a sample of 14 of the optically brightest radio-quiet quasars (m i ≤ 17.5 and z ≥ 1.9) in the Sloan Digital Sky Survey Data Release 5 quasar catalog that have C IV mini-broad absorption lines (mini-BALs) present in their spectra. X-ray data for 12 of the objects were obtained via a Chandra snapshot survey using ACIS-S, while data for the other two quasars were obtained from archival XMM-Newton observations. Joint X-ray spectral analysis shows that the mini-BAL quasars have a similar average power-law photon index (Γ ∼ 1.9) and level of intrinsic absorption (N H ∼ 21 cm -2 ) as non-BMB (neither BAL nor mini-BAL) quasars. Mini-BAL quasars are more similar to non-BMB quasars than to BAL quasars in their distribution of relative X-ray brightness (assessed with Δα ox ). Relative colors indicate mild dust reddening in the optical spectra of mini-BAL quasars. Significant correlations between Δα ox and UV absorption properties are confirmed for a sample of 56 sources combining mini-BAL and BAL quasars with high signal-to-noise ratio rest-frame UV spectra, which generally supports models in which X-ray absorption is important in enabling driving of the UV absorption-line wind. We also propose alternative parameterizations of the UV absorption properties of mini-BAL and BAL quasars, which may better describe the broad absorption troughs in some respects.

  15. Advanced signal separation and recovery algorithms for digital x-ray spectroscopy

    International Nuclear Information System (INIS)

    Mahmoud, Imbaby I.; El-Tokhy, Mohamed S.

    2015-01-01

    X-ray spectroscopy is widely used for in-situ applications for samples analysis. Therefore, spectrum drawing and assessment of x-ray spectroscopy with high accuracy is the main scope of this paper. A Silicon Lithium Si(Li) detector that cooled with a nitrogen is used for signal extraction. The resolution of the ADC is 12 bits. Also, the sampling rate of ADC is 5 MHz. Hence, different algorithms are implemented. These algorithms were run on a personal computer with Intel core TM i5-3470 CPU and 3.20 GHz. These algorithms are signal preprocessing, signal separation and recovery algorithms, and spectrum drawing algorithm. Moreover, statistical measurements are used for evaluation of these algorithms. Signal preprocessing based on DC-offset correction and signal de-noising is performed. DC-offset correction was done by using minimum value of radiation signal. However, signal de-noising was implemented using fourth order finite impulse response (FIR) filter, linear phase least-square FIR filter, complex wavelet transforms (CWT) and Kalman filter methods. We noticed that Kalman filter achieves large peak signal to noise ratio (PSNR) and lower error than other methods. However, CWT takes much longer execution time. Moreover, three different algorithms that allow correction of x-ray signal overlapping are presented. These algorithms are 1D non-derivative peak search algorithm, second derivative peak search algorithm and extrema algorithm. Additionally, the effect of signal separation and recovery algorithms on spectrum drawing is measured. Comparison between these algorithms is introduced. The obtained results confirm that second derivative peak search algorithm as well as extrema algorithm have very small error in comparison with 1D non-derivative peak search algorithm. However, the second derivative peak search algorithm takes much longer execution time. Therefore, extrema algorithm introduces better results over other algorithms. It has the advantage of recovering and

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-10-01

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

  18. Development of an image intensifier-TV digital imaging system with a multiple-slit scanning x-ray beam

    International Nuclear Information System (INIS)

    Kume, Y.; Doi, K.

    1986-01-01

    The authors are developing a new digital x-ray imaging system employing a multiple-slit assembly (MSA) and an image intensifier (II)-TV digital system. The final image consisting of primary radiation is digitally reconstructed from multiple slit images obtained with the MSA. This system can significantly reduce the scattered radiation from an object and the veiling glare from II-TV system. The quality of the reconstructed image is related to many parameters, such as slit width, the number of image frames, and the image reconstruction algorithm. They present the effect of these various parameters on basic imaging properties and the practicability of the method in comparison with conventional wide beam imaging

  19. Dentists' use of digital radiographic techniques: Part I - intraoral X-ray: a questionnaire study of Swedish dentists.

    Science.gov (United States)

    Svenson, Björn; Ståhlnacke, Katri; Karlsson, Reet; Fält, Anna

    2018-03-01

    The present study aims to gain knowledge about the dentist's use and choice of digital intraoral imaging methods. A questionnaire sent to 2481 dentists within the Swedish Dental Society contained questions about the type of X-ray technique used, problems experienced with digital radiography, and reasons for choosing digital technology, and about indications, clinic size and type of service. Response rate was 53%. Ninety-eight percent of the dentists had made the transition to digital radiography; only 2% used film technique, and solid-state detector (SSD) was the most used digital technique. More years in service decreases the likelihood of applying individual indications for performing a full mouth examination. More retakes were done with SSDs compared to storage phosphor plates. Reasons for choosing digital techniques were that work was easier and communication with the patients improved. However, dentists also experienced problems with digital techniques, such as exposure and projection errors and inadequate image quality. The Swedish Radiation Safety Authority states that all radiological examinations should be justified, something not always followed. This study showed that 98% of the respondents, Swedish dentists within the Swedish Dental Society, used digital techniques, and the most used was the solid-state technique.

  20. Maintaining radiation exposures as low as reasonably achievable (ALARA) for dental personnel operating portable hand-held x-ray equipment.

    Science.gov (United States)

    McGiff, Thomas J; Danforth, Robert A; Herschaft, Edward E

    2012-08-01

    Clinical experience indicates that newly available portable hand-held x-ray units provide advantages compared to traditional fixed properly installed and operated x-ray units in dental radiography. However, concern that hand-held x-ray units produce higher operator doses than fixed x-ray units has caused regulatory agencies to mandate requirements for use of hand-held units that go beyond those recommended by the manufacturer and can discourage the use of this technology. To assess the need for additional requirements, a hand-held x-ray unit and a pair of manikins were used to measure the dose to a simulated operator under two conditions: exposures made according to the manufacturer's recommendations and exposures made according to manufacturer's recommendation except for the removal of the x-ray unit's protective backscatter shield. Dose to the simulated operator was determined using an array of personal dosimeters and a pair of pressurized ion chambers. The results indicate that the dose to an operator of this equipment will be less than 0.6 mSv y⁻¹ if the device is used according to the manufacturer's recommendations. This suggests that doses to properly trained operators of well-designed, hand-held dental x-ray units will be below 1.0 mSv y⁻¹ (2% of the annual occupational dose limit) even if additional no additional operational requirements are established by regulatory agencies. This level of annual dose is similar to those reported as typical dental personnel using fixed x-ray units and appears to satisfy the ALARA principal for this class of occupational exposures.

  1. Development of cancer medical treatment/diagnostic equipment using the source of X-rays in space coherence

    International Nuclear Information System (INIS)

    Sato, Isamu; Shintomi, Kazutaka; Hayakawa, Ken

    2009-01-01

    In Nihon University, the research and development of Parametric X-rays radiation (PXR) by the 100 MeV electron linac are advanced. It was proved by basic experiment that PXR was a source of coherent X-rays. Coherent X-rays have the characteristic that a refraction action is guided with an irradiation matter. According to this action, the contrast image pick-up of an irradiation matter is attained, and X-rays becomes possible to focus a point itself. Research of cancer medical treatment and diagnosis are advanced using the new source of X-ray. Miniaturization of the source is important for the spread of cancer medical new treatment and diagnoses. Recently, the tabletop type 100 MeV class cryogenic linac with energy recovery is under development. In symposium, we report progress of these research and development. (author)

  2. Research on tomato seed vigor based on X-ray digital image

    Science.gov (United States)

    Zhao, Xueguan; Gao, Yuanyuan; Wang, Xiu; Li, Cuiling; Wang, Songlin; Feng, Qinghun

    2016-10-01

    Seed size, interior abnormal and damage of the tomato seeds will affect the germination. The purpose of this paper was to study the relationship between the internal morphology, seed size and seed germination of tomato. The preprocessing algorithm of X-ray image of tomato seeds was studied, and the internal structure characteristics of tomato seeds were extracted by image processing algorithm. By developing the image processing software, the cavity area between embryo and endosperm and the whole seed zone were determined. According to the difference of area of embryo and endosperm and Internal structural condition, seeds were divided into six categories, Respectively for three kinds of tomato seed germination test, the relationship between seed vigor and seed size , internal free cavity was explored through germination experiment. Through seedling evaluation test found that X-ray image analysis provide a perfect view of the inside part of the seed and seed morphology research methods. The larger the area of the endosperm and the embryo, the greater the probability of healthy seedlings sprout from the same size seeds. Mechanical damage adversely effects on seed germination, deterioration of tissue prone to produce week seedlings and abnormal seedlings.

  3. Application of X-ray digital radiography to online automated inspection of interior assembly structures of complex products

    International Nuclear Information System (INIS)

    Han Yueping; Han Yan; Li Ruihong; Wang Liming

    2009-01-01

    The paper proposes an application of X-ray digital radiography to online automated inspection and recognition of the interior assembly structures of complex products by means of the multiple views techniques. First, a vertical hybrid projection function (VHPF) is proposed as the recognition feature of a two-dimensional image. VHPF combines an integral projection function and a standard deviation function so that it can reflect the mean and the variance of the pixels in the vertical direction in an image. Secondly, by considering the different importance grades of objects inside the product and the independence of these objects along the circumference, the paper presents a hierarchical recognition method and uses a neural network system to speed up the computation process with parallel operations. Thirdly, using the whole-orientation features of one standard swatch and by extracting its maximal system of linear independence as the feature basis, the issue of blind areas for recognition is resolved. Based on this approach, the first domestic X-ray multi-view digital detection system has been developed and applied to the online detection of objects containing complicated assembly structures.

  4. Characterisation of Late Bronze Age large size shield nails by EDXRF, micro-EDXRF and X-ray digital radiography

    International Nuclear Information System (INIS)

    Figueiredo, E.; Araujo, M.F.; Silva, R.J.C.; Senna-Martinez, J.C.; Ines Vaz, J.L.

    2011-01-01

    In the present study six exceptional large size metallic nails, a dagger and a sickle from the Late Bronze Age archaeological site of Figueiredo das Donas (Central Portugal) have been analysed by EDXRF, micro-EDXRF and X-ray digital radiography for the study of material composition and technology of fabrication. The combination of these analytical and examination techniques showed that all artefacts are made of bronze with As, Sb and Pb impurities, and that the nails were most likely manufactured using the casting-on technique. These results reinforce the use of binary bronze by Late Bronze Age in the region, and the incorporation of new fabrication technologies that resulted from ancient spheres of interaction. - Highlights: → EDXRF, micro-EDXRF and X-ray digital radiography in cultural heritage studies. → Archaeometallurgical study of a Late Bronze Age artefact collection from Portugal. → Practise of a specific and traditional bronze metallurgy. → Appearance of technological innovations as the casting-on technique.

  5. A comparative study of the energy resolution achievable with digital signal processors in x-ray spectroscopy

    International Nuclear Information System (INIS)

    Geraci, A.; Zambusi, M.; Ripamonti, G.

    1996-01-01

    Interest for digital processing of signals from radiation detectors is subject to a growing attention due to its intrinsic adaptivity, easiness of calibration, etc. This work compares two digital processing methods: a multiple-delay-line (DL) N filter and a least-mean-squares (LMS) adaptive filter for applications in high resolution X-ray spectroscopy. The signal pulse, as appears at the output of a proper analog conditioning circuit, is digitized; the samples undergo a digital filtering procedure. Both digital filters take advantage of the possibility of synthesizing the best possible weighting function with respect to the actual noise conditions. A noticeable improvement of more than 10% in energy resolution has been achieved with both systems with respect to state-of-the-art systems based on analog circuitry. In particular, the two digital processors are shown to be the best choice respectively; for on-line use with critical ballistic deficit conditions and for very-high-resolution spectroscopy systems, ultimately limited by 1/f noise

  6. A comparative analysis of OTF, NPS, and DQE in energy integrating and photon counting digital x-ray detectors

    International Nuclear Information System (INIS)

    Acciavatti, Raymond J.; Maidment, Andrew D. A.

    2010-01-01

    is a binary function given as zero or unity everywhere. In analyzing the model detector with Gaussian blurring, the difference in NPS and DQE between the two detector types is found to increase with the blurring of the x-ray converter. Ultimately, the expression for the additive white noise of the photon counter is compared against the expression for electronic noise and secondary quantum noise in an energy integrator. Thus, a method is provided to determine the average secondary quanta that the energy integrator must produce for each x ray to have superior DQE to a photon counter with the same PSF. Conclusions: This article develops analytical models of OTF, NPS, and DQE for energy integrating and photon counting digital x-ray detectors. While many subtleties of real imaging systems have not been modeled, this work is illustrative in demonstrating an additive source of white noise in photon counting detectors which has not yet been described in the literature. One benefit of this analysis is a framework for determining the average secondary quanta that an energy integrating detector must produce for each x ray to have superior DQE to competing photon counting technology.

  7. Contribution to digital radiography. Study of a 2D X-ray sensor for mammography using the electrically-stimulated-luminescence effect

    International Nuclear Information System (INIS)

    Ayral, Jean-Luc

    1990-01-01

    Radiography is in a fast change period. This work describes the study and demonstration of a new type of 2D flat X-Ray sensor for mammography and delivering a digital signal. X-ray transmission study of breast tissues leads to: a-definition of X-Ray photons properties for optimized signal-to-noise ratio, and b-specifications of a 2D X-Ray sensor such as mean exposure, dynamic range and pixel size. Then the X-Ray detection processes using a direct or a delayed luminescence mechanism are reviewed. The detailed analysis of the different ways for detecting visible photons is combined with the system specifications (pixel size, image reading time) in order to characterize (from a signal-to-noise ratio aspect) an X-Ray imaging system integrating a delayed luminescence property. The imaging plate and associated luminescent material are specified by their minimum X-Ray absorption and conversion gain. The Gudden-Pohl effect, or Electrically Stimulated Luminescence (ESL) is experimentally studied and quantified under X-Ray excitation in ZnCdS: Cu, Al materials. An original UV sensitization technique opens us the way to highly reproducible results and large sensitivity. The obtained information storage time in the material is compatible with a delayed image reading. These results allow the achievement of an X-Ray imaging demonstrator integrating the ESL imaging plate, an intensified CCD sensor and the sensitization technique. First images are obtained. Further conception of real dimension X-Ray imaging system for mammography is described. (author) [fr

  8. Assessing the dose values received by patients during conventional radiography X-ray examinations and the technical condition of the equipment used for this purpose.

    Science.gov (United States)

    Bekas, Marcin; Pachocki, Krzysztof A; Waśniewska, Elżbieta; Bogucka, Dagmara; Magiera, Andrzej

    2014-01-01

    X-ray examination is associated with patient exposure to ionizing radiation. Dose values depend on the type of medical procedure used, the X-ray unit technical condition and exposure conditions selected. The aim of this study was to determine the dose value received by patients during certain conventional radiography X-ray examinations and to assess the technical condition of medical equipment used for this purpose. The study covered the total number of 118 conventional diagnostic X-ray units located in the Masovian Voivodeship. The methodology used to assess the conventional diagnostic X-ray unit technical condition and the measurement of the radiation dose rate received by patients are based on test procedures developed by the Department of Radiation Protection and Radiobiology of the National Institute of Public Health - National Institute of Hygiene (Warszawa, Poland) accredited for compliance with PN-EN 17025 standard by the Polish Centre for Accreditation. It was found that 84.7% of X-ray units fully meet the criteria set out in the Polish legislation regarding the safe use of ionizing radiation in medicine, while 15.3% of the units do not meet some of them. The broadest dose value range was recorded for adult patients. Particularly, during lateral (LATl) lumbar spine radiography the recorded entrance surface dose (ESD) values ranged from 283.5 to 7827 µGy (mean: 2183.3 µGy). It is absolutely necessary to constantly monitor the technical condition of all X-ray units, because it affects population exposure to ionizing radiation. Furthermore, it is essential to raise radiographers' awareness of the effects that ionizing radiation exposure can have on the human body.

  9. Monte Carlo derivation of filtered tungsten anode X-ray spectra for dose computation in digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Paixao, L.; Oliveira, B. B.; Nogueira, M. do S. [Centro de Desenvolvimento da Tecnologia Nuclear, Post-graduation in Science and Technology of Radiations, Minerals and Materials, Pte. Antonio Carlos 6.627, Pampulha, 31270-901 Belo Horizonte (Brazil); Viloria, C. [UFMG, Departamento de Engenharia Nuclear, Post-graduation in Nuclear Sciences and Techniques, Pte. Antonio Carlos 6.627, Pampulha, 31270-901 Belo Horizonte (Brazil); Alves de O, M. [UFMG, Department of Anatomy and Imaging, Prof. Alfredo Balena 190, 30130-100 Belo Horizonte (Brazil); Araujo T, M. H., E-mail: lpr@cdtn.br [Dr Maria Helena Araujo Teixeira Clinic, Guajajaras 40, 30180-100 Belo Horizonte (Brazil)

    2014-08-15

    It is widely accepted that the mean glandular dose (D{sub G}) for the glandular tissue is the more useful magnitude for characterizing the breast cancer risk. The procedure to estimate the D{sub G}, for being difficult to measure it directly in the breast, it is to make the use of conversion factors that relate incident air kerma (K{sub i}) at this dose. Generally, the conversion factors vary with the x-ray spectrum half-value layer and the breast composition and thickness. Several authors through computer simulations have calculated such factors by the Monte Carlo (Mc) method. Many spectral models for D{sub G} computer simulations purposes are available in the diagnostic range. One of the models available generates unfiltered spectra. In this work, the Monte Carlo EGSnrc code package with the C++ class library (eg spp) was employed to derive filtered tungsten x-ray spectra used in digital mammography systems. Filtered spectra for rhodium and aluminium filters were obtained for tube potentials between 26 and 32 kV. The half-value layer of simulated filtered spectra were compared with those obtained experimentally with a solid state detector Unfors model 8202031-H Xi R/F and Mam Detector Platinum and 8201023-C Xi Base unit Platinum Plus w m As in a Hologic Selenia Dimensions system using a Direct Radiography mode. Calculated half-value layer values showed good agreement compared to those obtained experimentally. These results show that the filtered tungsten anode x-ray spectra and the EGSnrc Mc code can be used for D{sub G} determination in mammography. (Author)

  10. Monte Carlo derivation of filtered tungsten anode X-ray spectra for dose computation in digital mammography

    International Nuclear Information System (INIS)

    Paixao, L.; Oliveira, B. B.; Nogueira, M. do S.; Viloria, C.; Alves de O, M.; Araujo T, M. H.

    2014-08-01

    It is widely accepted that the mean glandular dose (D G ) for the glandular tissue is the more useful magnitude for characterizing the breast cancer risk. The procedure to estimate the D G , for being difficult to measure it directly in the breast, it is to make the use of conversion factors that relate incident air kerma (K i ) at this dose. Generally, the conversion factors vary with the x-ray spectrum half-value layer and the breast composition and thickness. Several authors through computer simulations have calculated such factors by the Monte Carlo (Mc) method. Many spectral models for D G computer simulations purposes are available in the diagnostic range. One of the models available generates unfiltered spectra. In this work, the Monte Carlo EGSnrc code package with the C++ class library (eg spp) was employed to derive filtered tungsten x-ray spectra used in digital mammography systems. Filtered spectra for rhodium and aluminium filters were obtained for tube potentials between 26 and 32 kV. The half-value layer of simulated filtered spectra were compared with those obtained experimentally with a solid state detector Unfors model 8202031-H Xi R/F and Mam Detector Platinum and 8201023-C Xi Base unit Platinum Plus w m As in a Hologic Selenia Dimensions system using a Direct Radiography mode. Calculated half-value layer values showed good agreement compared to those obtained experimentally. These results show that the filtered tungsten anode x-ray spectra and the EGSnrc Mc code can be used for D G determination in mammography. (Author)

  11. 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 ...

  12. Development and assessment of a digital X-ray software tool to determine vertebral rotation in adolescent idiopathic scoliosis.

    Science.gov (United States)

    Eijgenraam, Susanne M; Boselie, Toon F M; Sieben, Judith M; Bastiaenen, Caroline H G; Willems, Paul C; Arts, Jacobus J; Lataster, Arno

    2017-02-01

    The amount of vertebral rotation in the axial plane is of key importance in the prognosis and treatment of adolescent idiopathic scoliosis (AIS). Current methods to determine vertebral rotation are either designed for use in analogue plain radiographs and not useful in digital images, or lack measurement precision and are therefore less suitable for the follow-up of rotation in AIS patients. This study aimed to develop a digital X-ray software tool with high measurement precision to determine vertebral rotation in AIS, and to assess its (concurrent) validity and reliability. In this study a combination of basic science and reliability methodology applied in both laboratory and clinical settings was used. Software was developed using the algorithm of the Perdriolle torsion meter for analogue AP plain radiographs of the spine. Software was then assessed for (1) concurrent validity and (2) intra- and interobserver reliability. Plain radiographs of both human cadaver vertebrae and outpatient AIS patients were used. Concurrent validity was measured by two independent observers, both experienced in the assessment of plain radiographs. Reliability-measurements were performed by three independent spine surgeons. Pearson correlation of the software compared with the analogue Perdriolle torsion meter for mid-thoracic vertebrae was 0.98, for low-thoracic vertebrae 0.97 and for lumbar vertebrae 0.97. Measurement exactness of the software was within 5° in 62% of cases and within 10° in 97% of cases. Intraclass correlation coefficient (ICC) for inter-observer reliability was 0.92 (0.91-0.95), ICC for intra-observer reliability was 0.96 (0.94-0.97). We developed a digital X-ray software tool to determine vertebral rotation in AIS with a substantial concurrent validity and reliability, which may be useful for the follow-up of vertebral rotation in AIS patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Digital X-ray radiogrammetry better identifies osteoarthritis patients with a low bone mineral density than quantitative ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Goerres, Gerhard W. [University Hospital Zurich, Institute of Diagnostic Radiology, Department of Medical Radiology, Zurich (Switzerland); University Hospital Zurich, Osteoporosis Center, Zurich (Switzerland); Frey, Diana; Studer, Annina; Hauser, Dagmar; Zilic, Nathalie [University Hospital Zurich, Osteoporosis Center, Zurich (Switzerland); Hany, Thomas F. [University Hospital Zurich, Institute of Nuclear Medicine, Department of Medical Radiology, Zurich (Switzerland); Seifert, Burkhardt [University of Zurich, Department of Biostatistics, Zurich (Switzerland); Haeuselmann, Hans J. [Center for Rheumatology and Bone Disease, Klinik im Park, Zurich (Switzerland); Michel, Beat A.; Uebelhart, Daniel [University Hospital Zurich, Osteoporosis Center, Zurich (Switzerland); University Hospital Zurich, Department of Rheumatology and Institute of Physical Medicine, Zurich (Switzerland); Hans, Didier [University Hospital Geneva, Division of Nuclear Medicine, Geneva (Switzerland)

    2007-04-15

    This study assessed the ability of quantitative ultrasound (QUS) and digital X-ray radiogrammetry (DXR) to identify osteopenia and osteoporosis in patients with knee osteoarthritis (OA). One hundred and sixty-one patients with painful knee OA (81 men, 80 women; age 62.6{+-}9.2 years, range 40-82 years) were included in this cross-sectional study and underwent dual-energy X-ray absorptiometry (DXA) of both hips and the lumbar spine, QUS of the phalanges and calcanei of both hands and heels, and DXR using radiographs of both hands. Unpaired t-test, Mann-Whitney U test, ROC analysis and Spearman's rank correlation were used for comparisons and correlation of methods. Using DXA as the reference standard, we defined a low bone mineral density (BMD) as a T-score {<=}-1.0 at the lumbar spine or proximal femur. In contrast to phalangeal or calcaneal QUS, DXR was able to discriminate patients with a low BMD at the lumbar spine (p<0.0001) or hips (p<0.0001). ROC analysis showed that DXR had an acceptable predictive power in identifying OA patients a low hip BMD (sensitivity 70%, specificity 71%). Therefore, DXR used as a screening tool could help in identifying patients with knee OA for DXA. (orig.)

  14. submitter Digital Image Correlation of 2D X-ray Powder Diffraction Data for Lattice Strain Evaluation

    CERN Document Server

    Zhang, Hongjia; Salvati, Enrico; Daisenberger, Dominik; Lunt, Alexander J G; Fong, Kai Soon; Song, Xu; Korsunsky, Alexander M

    2018-01-01

    High energy 2D X-ray powder diffraction experiments are widely used for lattice strain measurement. The 2D to 1D conversion of diffraction patterns is a necessary step used to prepare the data for full pattern refinement, but is inefficient when only peak centre position information is required for lattice strain evaluation. The multi-step conversion process is likely to lead to increased errors associated with the ‘caking’ (radial binning) or fitting procedures. A new method is proposed here that relies on direct Digital Image Correlation analysis of 2D X-ray powder diffraction patterns (XRD-DIC, for short). As an example of using XRD-DIC, residual strain values along the central line in a Mg AZ31B alloy bar after 3-point bending are calculated by using both XRD-DIC and the conventional ‘caking’ with fitting procedures. Comparison of the results for strain values in different azimuthal angles demonstrates excellent agreement between the two methods. The principal strains and directions are calculated...

  15. Setting up processes and standardization of the equipment in order to optimize analyses of the wavelength dispersion X-ray fluorescence (WDXRF) system

    International Nuclear Information System (INIS)

    Phan Trong Phuc; Luu Anh Tuyen; La Ly Nguyen; Nguyen Thi Ngoc Hue; Pham Thi Hue; Do Duy Khiem

    2015-01-01

    For the purpose of operating and optimizing the analyses of the equipment: wavelength dispersion X-ray fluorescence (WDXRF)- model S8 TIGER from Enhancing Equipment Project (TCTTB) 2011-2012, we set up sampling and analytical process for different sample kinds; we constructed multi-elemental calibration curve for clay sample; we analysed elemental concentrations of 5 clay samples by XRF method and compared the results with the results given by NAA method. Equipment sensitivity was tested by analysing elemental concentrations of 2 Kaolin standard samples. The results show that S8-Tiger equipment is within good condition and is able to analyze powder clay sample exactly. (author)

  16. X-ray focal spot reconstruction by circular penumbra analysis-Application to digital radiography systems.

    Science.gov (United States)

    Di Domenico, Giovanni; Cardarelli, Paolo; Contillo, Adriano; Taibi, Angelo; Gambaccini, Mauro

    2016-01-01

    The quality of a radiography system is affected by several factors, a major one being the focal spot size of the x-ray tube. In fact, the measurement of such size is recognized to be of primary importance during acceptance tests and image quality evaluations of clinical radiography systems. The most common device providing an image of the focal spot emission distribution is a pin-hole camera, which requires a high tube loading in order to produce a measurable signal. This work introduces an alternative technique to obtain an image of the focal spot, through the processing of a single radiograph of a simple test object, acquired with a suitable magnification. The radiograph of a magnified sharp edge is a well-established method to evaluate the extension of the focal spot profile along the direction perpendicular to the edge. From a single radiograph of a circular x-ray absorber, it is possible to extract simultaneously the radial profiles of several sharp edges with different orientations. The authors propose a technique that allows to obtain an image of the focal spot through the processing of these radial profiles by means of a pseudo-CT reconstruction technique. In order to validate this technique, the reconstruction has been applied to the simulated radiographs of an ideal disk-shaped absorber, generated by various simulated focal spot distributions. Furthermore, the method has been applied to the focal spot of a commercially available mammography unit. In the case of simulated radiographs, the results of the reconstructions have been compared to the original distributions, showing an excellent agreement for what regards both the overall distribution and the full width at half maximum measurements. In the case of the experimental test, the method allowed to obtain images of the focal spot that have been compared with the results obtained through standard techniques, namely, pin-hole camera and slit camera. The method was proven to be effective for simulated

  17. X-ray focal spot reconstruction by circular penumbra analysis—Application to digital radiography systems

    Energy Technology Data Exchange (ETDEWEB)

    Di Domenico, Giovanni, E-mail: didomenico@fe.infn.it; Cardarelli, Paolo; Taibi, Angelo; Gambaccini, Mauro [Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, via Saragat 1, FE I-44122, Italy and INFN - sezione di Ferrara, via Saragat 1, FE I-44122 (Italy); Contillo, Adriano [Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, via Saragat 1, FE I-44122 (Italy)

    2016-01-15

    Purpose: The quality of a radiography system is affected by several factors, a major one being the focal spot size of the x-ray tube. In fact, the measurement of such size is recognized to be of primary importance during acceptance tests and image quality evaluations of clinical radiography systems. The most common device providing an image of the focal spot emission distribution is a pin-hole camera, which requires a high tube loading in order to produce a measurable signal. This work introduces an alternative technique to obtain an image of the focal spot, through the processing of a single radiograph of a simple test object, acquired with a suitable magnification. Methods: The radiograph of a magnified sharp edge is a well-established method to evaluate the extension of the focal spot profile along the direction perpendicular to the edge. From a single radiograph of a circular x-ray absorber, it is possible to extract simultaneously the radial profiles of several sharp edges with different orientations. The authors propose a technique that allows to obtain an image of the focal spot through the processing of these radial profiles by means of a pseudo-CT reconstruction technique. In order to validate this technique, the reconstruction has been applied to the simulated radiographs of an ideal disk-shaped absorber, generated by various simulated focal spot distributions. Furthermore, the method has been applied to the focal spot of a commercially available mammography unit. Results: In the case of simulated radiographs, the results of the reconstructions have been compared to the original distributions, showing an excellent agreement for what regards both the overall distribution and the full width at half maximum measurements. In the case of the experimental test, the method allowed to obtain images of the focal spot that have been compared with the results obtained through standard techniques, namely, pin-hole camera and slit camera. Conclusions: The method was

  18. Proposed limiting values for performance criteria in acceptance testing of diagnostic X-ray equipment in the Federal Republic of Germany

    International Nuclear Information System (INIS)

    Baeuml, A.

    1989-01-01

    In the Federal Republic of Germany a new X-ray ordinance came into force in 1988 containing a specific paragraph on quality assurance for all medical X-ray units stipulating acceptance tests, regular checks and supervision by medical bodies and the competent authorities. Acceptance testing is to be performed by engineers from equipment suppliers of manufacturers in new and existing installations. It is expected that the service engineers will adjust the equipment in such a way as to obtain optimal performance before measurements are made, the results of which are to be stated in a certificate describing quality status of the equipment. A working group has developed guidelines for these acceptance tests. Items to be measured are reported and proposed limiting values and their tolerances are discussed. (author)

  19. Proposed limiting values for performance criteria in acceptance testing of diagnostic X-ray equipment in the Federal Republic of Germany

    International Nuclear Information System (INIS)

    Baeuml, A.

    1989-01-01

    In the Federal Republic of Germany a new X-ray ordinance came into force in 1988 containing a specific paragraph on quality assurance for all medical X-ray units stipulating acceptance tests, regular checks and supervision by medical bodies and the competent authorities. Acceptance testing is to be performed by engineers from the equipment suppliers or manufacturers in new and also existing installations. It is expected that the service engineers will adjust the equipment in such a way as to obtain optimal performance before measurements are made, the results of which are to be stated in a certificate describing the quality status of the equipment. A working group has developed guidelines for these acceptance tests. The items to be measured are reported and the proposed limiting values and their tolerances are discussed. (author)

  20. Dose efficiency and low-contrast detectability of an amorphous silicon x-ray detector for digital radiography

    International Nuclear Information System (INIS)

    Aufrichtig, Richard

    2000-01-01

    The effect of dose reduction on low-contrast detectability is investigated theoretically and experimentally for a production grade amorphous silicon (a-Si) x-ray detector and compared with a standard thoracic screen-film combination. A non-prewhitening matched filter observer model modified to include a spatial response function and internal noise for the human visual system (HVS) is used to calculate a signal-to-noise ratio (SNR) related to object detectability. Other inputs to the SNR calculation are the detective quantum efficiency (DQE) and the modulation transfer function (MTF) of the imaging system. Besides threshold detectability, the model predicts the equivalent perception dose ratio (EPDR), which is the fraction of the screen-film exposure for which the digital detector provides equal detectability. Images of a contrast-detail phantom are obtained with the digital detector at dose levels corresponding to 27%, 41%, 63% and 100% of the dose used for screen-film. The images are used in a four-alternative forced choice (4-AFC) observer perception study in order to measure threshold detectability. A statistically significant improvement in contrast detectability is measured with the digital detector at 100% and 63% of the screen-film dose. There is no statistical difference between screen-film and digital at 41% of the dose. On average, the experimental EPDR is 44%, which agrees well with the model prediction of 40%. (author)

  1. High-throughput measurement of rice tillers using a conveyor equipped with x-ray computed tomography

    Science.gov (United States)

    Yang, Wanneng; Xu, Xiaochun; Duan, Lingfeng; Luo, Qingming; Chen, Shangbin; Zeng, Shaoqun; Liu, Qian

    2011-02-01

    Tillering is one of the most important agronomic traits because the number of shoots per plant determines panicle number, a key component of grain yield. The conventional method of counting tillers is still manual. Under the condition of mass measurement, the accuracy and efficiency could be gradually degraded along with fatigue of experienced staff. Thus, manual measurement, including counting and recording, is not only time consuming but also lack objectivity. To automate this process, we developed a high-throughput facility, dubbed high-throughput system for measuring automatically rice tillers (H-SMART), for measuring rice tillers based on a conventional x-ray computed tomography (CT) system and industrial conveyor. Each pot-grown rice plant was delivered into the CT system for scanning via the conveyor equipment. A filtered back-projection algorithm was used to reconstruct the transverse section image of the rice culms. The number of tillers was then automatically extracted by image segmentation. To evaluate the accuracy of this system, three batches of rice at different growth stages (tillering, heading, or filling) were tested, yielding absolute mean absolute errors of 0.22, 0.36, and 0.36, respectively. Subsequently, the complete machine was used under industry conditions to estimate its efficiency, which was 4320 pots per continuous 24 h workday. Thus, the H-SMART could determine the number of tillers of pot-grown rice plants, providing three advantages over the manual tillering method: absence of human disturbance, automation, and high throughput. This facility expands the application of agricultural photonics in plant phenomics.

  2. Digital image evaluation for the determination of morphometric sizes for periodontal X-ray diagnosis and selective coronary angiography

    International Nuclear Information System (INIS)

    Barth, K.

    1982-01-01

    In its uses in the areas of periodontology and coronary angiography it is shown, how the digital image evaluation expands the possibilities of x-ray diagnosis and how it improves the objectivity and exactness of the evaluation. For the accomplishment of this task a detailed analysis of the morphological data is undertaken. The results of the analysis lead to a mathematical structure model. Based on this model the recognition and measuring of the object in an adaptive heuristic process is undertaken. In this case it dealt with a desmodontal split, whose change is indicated by a periodontal bone atrophy. The contour recognition is embedded in a newly created image processing system, which allows itself to be used generally and is shown using the presentation of coronary vessels as an example. The exactness of the automatic image evaluation in comparison to the measuring done by the doctor is discussed. (orig./TRV) [de

  3. Qualification of a digital radiographic equipment for thin weld inspection

    International Nuclear Information System (INIS)

    Boulanger, G.; Furlan, J.

    1988-04-01

    The level of quality asked for welding plugs to fuel pins requires to test all the welds, that is to say about 200 000 welds of the fuel assemblies of the fast reactor Super-Phenix. X-ray radiography is one of the tests. Before the operation was done on a film by the personnel automatic selection of tested material and image processing are substituted to the film in the digital radiographic equipment IRENE. Main advantages are: elimination of human factor in defect appreciation, reliability of image processing and instant availability. On 1000 welds a good correlation is obtained between results on films and those of image processing [fr

  4. Real-time digital filtering, event triggering, and tomographic reconstruction of JET soft x-ray data (abstract)

    Science.gov (United States)

    Edwards, A. W.; Blackler, K.; Gill, R. D.; van der Goot, E.; Holm, J.

    1990-10-01

    Based upon the experience gained with the present soft x-ray data acquisition system, new techniques are being developed which make extensive use of digital signal processors (DSPs). Digital filters make 13 further frequencies available in real time from the input sampling frequency of 200 kHz. In parallel, various algorithms running on further DSPs generate triggers in response to a range of events in the plasma. The sawtooth crash can be detected, for example, with a delay of only 50 μs from the onset of the collapse. The trigger processor interacts with the digital filter boards to ensure data of the appropriate frequency is recorded throughout a plasma discharge. An independent link is used to pass 780 and 24 Hz filtered data to a network of transputers. A full tomographic inversion and display of the 24 Hz data is carried out in real time using this 15 transputer array. The 780 Hz data are stored for immediate detailed playback following the pulse. Such a system could considerably improve the quality of present plasma diagnostic data which is, in general, sampled at one fixed frequency throughout a discharge. Further, it should provide valuable information towards designing diagnostic data acquisition systems for future long pulse operation machines when a high degree of real-time processing will be required, while retaining the ability to detect, record, and analyze events of interest within such long plasma discharges.

  5. X-ray imaging using amorphous selenium: a photoinduced discharge readout method for digital mammography.

    Science.gov (United States)

    Rowlands, J A; Hunter, D M; Araj, N

    1991-01-01

    A new digital image readout method for electrostatic charge images on photoconductive plates is described. The method can be used to read out images on selenium plates similar to those used in xeromammography. The readout method, called the air-gap photoinduced discharge method (PID), discharges the latent image pixel by pixel and measures the charge. The PID readout method, like electrometer methods, is linear. However, the PID method permits much better resolution than scanning electrometers while maintaining quantum limited performance at high radiation exposure levels. Thus the air-gap PID method appears to be uniquely superior for high-resolution digital imaging tasks such as mammography.

  6. Fully automated joint space width measurement and digital X-ray radiogrammetry in early RA

    NARCIS (Netherlands)

    Platten, Michael; Kisten, Yogan; Kälvesten, Johan; Arnaud, Laurent; Forslind, Kristina; van Vollenhoven, Ronald

    2017-01-01

    To study fully automated digital joint space width (JSW) and bone mineral density (BMD) in relation to a conventional radiographic scoring method in early rheumatoid arthritis (eRA). Radiographs scored by the modified Sharp van der Heijde score (SHS) in patients with eRA were acquired from the

  7. Testing strategies for digital picture processing of industrial X-ray images

    International Nuclear Information System (INIS)

    Filbert, D.; Klatte, R.

    1986-01-01

    Digital picture processing for difficult inspection work in general involves long and complex processing and much computer time. An adequate testing strategy can considerably reduce the testing time, which is shown by the example of a strategy for automated radiographic testing of castings. (orig./HP) [de

  8. Kinematics of the orbital movement of a digital X-ray scanner of annular pipe seams

    Directory of Open Access Journals (Sweden)

    Vasilchenko Rostislav

    2018-01-01

    Full Text Available The features of the kinematics of devices performing orbital displacements are considered. Different versions of the arrangement of mechanisms for the orbital movement of a digital radiographic scanner are compared. The load capacity of the support flexible joint of the mechanism was estimated.

  9. Si(Li) x-ray spectrometer with signal processing system based on digital filtering

    International Nuclear Information System (INIS)

    Lakatos, Tamas

    1985-01-01

    A new signal processing system is under development at ATOMKI, Debrecen, Hungary, based on digital filtering by a microprocessor. The advantages of the new method are summarized. Dead time can be decreased and the speed of signal processing can be increased. Computer simulations verified the theoretical conclusions. (D.Gy.)

  10. Systematic errors in digital volume correlation due to the self-heating effect of a laboratory x-ray CT scanner

    International Nuclear Information System (INIS)

    Wang, B; Pan, B; Tao, R; Lubineau, G

    2017-01-01

    The use of digital volume correlation (DVC) in combination with a laboratory x-ray computed tomography (CT) for full-field internal 3D deformation measurement of opaque materials has flourished in recent years. During x-ray tomographic imaging, the heat generated by the x-ray tube changes the imaging geometry of x-ray scanner, and further introduces noticeable errors in DVC measurements. In this work, to provide practical guidance high-accuracy DVC measurement, the errors in displacements and strains measured by DVC due to the self-heating for effect of a commercially available x-ray scanner were experimentally investigated. The errors were characterized by performing simple rescan tests with different scan durations. The results indicate that the maximum strain errors associated with the self-heating of the x-ray scanner exceed 400 µε . Possible approaches for minimizing or correcting these displacement and strain errors are discussed. Finally, a series of translation and uniaxial compression tests were performed, in which strain errors were detected and then removed using pre-established artificial dilatational strain-time curve. Experimental results demonstrate the efficacy and accuracy of the proposed strain error correction approach. (paper)

  11. Systematic errors in digital volume correlation due to the self-heating effect of a laboratory x-ray CT scanner

    KAUST Repository

    Wang, B

    2017-02-15

    The use of digital volume correlation (DVC) in combination with a laboratory x-ray computed tomography (CT) for full-field internal 3D deformation measurement of opaque materials has flourished in recent years. During x-ray tomographic imaging, the heat generated by the x-ray tube changes the imaging geometry of x-ray scanner, and further introduces noticeable errors in DVC measurements. In this work, to provide practical guidance high-accuracy DVC measurement, the errors in displacements and strains measured by DVC due to the self-heating for effect of a commercially available x-ray scanner were experimentally investigated. The errors were characterized by performing simple rescan tests with different scan durations. The results indicate that the maximum strain errors associated with the self-heating of the x-ray scanner exceed 400 µε. Possible approaches for minimizing or correcting these displacement and strain errors are discussed. Finally, a series of translation and uniaxial compression tests were performed, in which strain errors were detected and then removed using pre-established artificial dilatational strain-time curve. Experimental results demonstrate the efficacy and accuracy of the proposed strain error correction approach.

  12. The tendency of medical electrical equipment - IEC 60601-2-54: Particular requirements for the basic safety and essential performance of x-ray equipment for radiography and radioscopy

    International Nuclear Information System (INIS)

    Roh, Young Hoon; Kim, Jung Min

    2015-01-01

    Medical electrical equipment - Part 1: General requirement for basic safety and essential performance of MFDS was revised as 3th edition and Medical electrical equipment Part 2-54: Particular requirements for the basic safety and essential performance of X-ray equipment will be expected to be announced as notification. Therefore this technical report was written to introduce provision of the particular requirements, replacement, addition, amendment. The purpose of this particular requirements is to secure requirements for basic safety and essential performance of X-ray equipment for radiography and radioscopy. X-ray high voltage generator, mechanical protective device, protection against radiation is included in this particular requirements. Medical electrical equipment - Part 1, Part 1-2, Part 1-3 is applied to this particular requirements. If the requirements is announced as notification, It is expected to widen understanding for basic safety and essential performance of X-ray equipment for radiography and radioscopy and play a part to internationalize of medical equipment

  13. Research of the X-ray spectrum in the digital image acquisition and processing for internal disturbs detection in mangoes (Mangifera indica l.)

    International Nuclear Information System (INIS)

    Ferreira, Rubemar S.; Freire Junior, Murillo; Botrel, Neide; Jesus, Edgar de

    2002-01-01

    In this work, digital image processing was associated to X-ray beam relevant to watching internal injuries, such as breakdown, soft nose and other physiological disturbs in mangoes CV Tommy Atkins. The X-ray source was a high frequency generator operating to a high tension between 14 to 35 kV on a molybdenum target tube, which generate X-ray characteristic near from 18,5 keV and 20 keV (k an l shell) plus a continuous spectrum, thought to be proper to get radiological images from mangoes in different maturation stages. Different filtrations and pseudo-colors technique were used to process the digital images produced. Results, from a group of comparative images, show the feasibility to detect several classes of internal disorders as well as others produced in packing houses and transport of mangoes. (author)

  14. Radiometer evaluation of X-rays equipment in the region of Aracatuba, Sao Paulo, Brazil;Avaliacao radiometrica de raios-X na regiao de Aracatuba, Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Marco A.R. [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina; Kanezawa, Jorge S. [Centro de Ensino e Tecnologia de Aracatuba (CETEA), SP (Brazil)

    2009-07-01

    This paper presents the basic concepts of radiation protection to guide the health care professionals who use equipment emitting ionizing radiation on the correct handling of the beams of radiation. Radiometric evaluations were conducted in 1665 in X-ray equipment, installed in dental surgeries and clinics, hospitals and radiology services, during the years 1996 to 2003 in the region of Aracatuba. Tests of radiometry are presented as a technical report where the parameters are quantified physical and radiological verifying its compliance with the established by legislation. The distribution of reports by type of unit shows that the vast majority of equipment is of periapical dental x-rays (72%), 25% of equipment is medical equipment for radiology and 3% is dental equipment panoramic model (orthodontic documentation). Among the physical parameters analyzed, the length of the browser was showing more variance compared to the required by law, this fact may also contribute to gaps in the rate of the radiation dose and the size of field in the skin of the patient, the that can easily be resolved simply to replace the piece at the outlet of the head. During the completion of visits to services, it also noted a gap in the training of professionals who operate this equipment emitting radiation, warning of the need for specific training in the area. (author)

  15. Volume digital image correlation to assess displacement field in compression loaded bread crumb under X-ray microtomography

    KAUST Repository

    Moussawi, Ali

    2014-10-01

    In this study, we present an original approach to assess structural changes during bread crumb compression using a mechanical testing bench coupled to 3D X-ray microtomography. X-ray images taken at different levels of compression of the bread crumb are processed using image analysis. A subset-based digital volume correlation method is used to achieve the 3D displacement field. Within the limit of the approach, deterministic search strategy is implemented for solving subset displacement in each deformed image with regards to the undeformed one. The predicted displacement field in the transverse directions shows differences that depend on local cell arrangement as confirmed by finite element analysis. The displacement component in the loading direction is affected by the magnitude of imposed displacement and shows more regular change. Large displacement levels in the compression direction are in good agreement with the imposed experimental displacement. The results presented here are promising in a sense of possible identification of local foam properties. New insights are expected to achieve better understanding of structural heterogeneities in the overall perception of the product. Industrial relevance: Texture evaluation of cereal product is an important aspect for testing consumer acceptability of new designed products. Mechanical evaluation of backed products is a systemic route for determining texture of cereal based product. From the industrial viewpoint, mechanical evaluation allows saving both time and cost compared to panel evaluation. We demonstrate that better understanding of structural changes during texture evaluation can be achieved in addition to texture evaluation. Sensing structural changes during bread crumb compression is achievable by combining novel imaging technique and processing based on image analysis. We present thus an efficient way to predict displacements during compression of freshly baked product. This method can be used in different

  16. The design and imaging characteristics of dynamic, solid-state, flat-panel x-ray image detectors for digital fluoroscopy and fluorography

    International Nuclear Information System (INIS)

    Cowen, A.R.; Davies, A.G.; Sivananthan, M.U.

    2008-01-01

    Dynamic, flat-panel, solid-state, x-ray image detectors for use in digital fluoroscopy and fluorography emerged at the turn of the millennium. This new generation of dynamic detectors utilize a thin layer of x-ray absorptive material superimposed upon an electronic active matrix array fabricated in a film of hydrogenated amorphous silicon (a-Si:H). Dynamic solid-state detectors come in two basic designs, the indirect-conversion (x-ray scintillator based) and the direct-conversion (x-ray photoconductor based). This review explains the underlying principles and enabling technologies associated with these detector designs, and evaluates their physical imaging characteristics, comparing their performance against the long established x-ray image intensifier television (TV) system. Solid-state detectors afford a number of physical imaging benefits compared with the latter. These include zero geometrical distortion and vignetting, immunity from blooming at exposure highlights and negligible contrast loss (due to internal scatter). They also exhibit a wider dynamic range and maintain higher spatial resolution when imaging over larger fields of view. The detective quantum efficiency of indirect-conversion, dynamic, solid-state detectors is superior to that of both x-ray image intensifier TV systems and direct-conversion detectors. Dynamic solid-state detectors are playing a burgeoning role in fluoroscopy-guided diagnosis and intervention, leading to the displacement of x-ray image intensifier TV-based systems. Future trends in dynamic, solid-state, digital fluoroscopy detectors are also briefly considered. These include the growth in associated three-dimensional (3D) visualization techniques and potential improvements in dynamic detector design

  17. Detection of tuberculosis patterns in digital photographs of chest X-ray images using Deep Learning: feasibility study.

    Science.gov (United States)

    Becker, A S; Blüthgen, C; Phi van, V D; Sekaggya-Wiltshire, C; Castelnuovo, B; Kambugu, A; Fehr, J; Frauenfelder, T

    2018-03-01

    To evaluate the feasibility of Deep Learning-based detection and classification of pathological patterns in a set of digital photographs of chest X-ray (CXR) images of tuberculosis (TB) patients. In this prospective, observational study, patients with previously diagnosed TB were enrolled. Photographs of their CXRs were taken using a consumer-grade digital still camera. The images were stratified by pathological patterns into classes: cavity, consolidation, effusion, interstitial changes, miliary pattern or normal examination. Image analysis was performed with commercially available Deep Learning software in two steps. Pathological areas were first localised; detected areas were then classified. Detection was assessed using receiver operating characteristics (ROC) analysis, and classification using a confusion matrix. The study cohort was 138 patients with human immunodeficiency virus (HIV) and TB co-infection (median age 34 years, IQR 28-40); 54 patients were female. Localisation of pathological areas was excellent (area under the ROC curve 0.82). The software could perfectly distinguish pleural effusions from intraparenchymal changes. The most frequent misclassifications were consolidations as cavitations, and miliary patterns as interstitial patterns (and vice versa). Deep Learning analysis of CXR photographs is a promising tool. Further efforts are needed to build larger, high-quality data sets to achieve better diagnostic performance.

  18. Estimates of Average Glandular Dose with Auto-modes of X-ray Exposures in Digital Breast Tomosynthesis

    Directory of Open Access Journals (Sweden)

    Izdihar Kamal

    2015-05-01

    Full Text Available Objectives: The aim of this research was to examine the average glandular dose (AGD of radiation among different breast compositions of glandular and adipose tissue with auto-modes of exposure factor selection in digital breast tomosynthesis. Methods: This experimental study was carried out in the National Cancer Society, Kuala Lumpur, Malaysia, between February 2012 and February 2013 using a tomosynthesis digital mammography X-ray machine. The entrance surface air kerma and the half-value layer were determined using a 100H thermoluminescent dosimeter on 50% glandular and 50% adipose tissue (50/50 and 20% glandular and 80% adipose tissue (20/80 commercially available breast phantoms (Computerized Imaging Reference Systems, Inc., Norfolk, Virginia, USA with auto-time, auto-filter and auto-kilovolt modes. Results: The lowest AGD for the 20/80 phantom with auto-time was 2.28 milliGray (mGy for two dimension (2D and 2.48 mGy for three dimensional (3D images. The lowest AGD for the 50/50 phantom with auto-time was 0.97 mGy for 2D and 1.0 mGy for 3D. Conclusion: The AGD values for both phantoms were lower against a high kilovolt peak and the use of auto-filter mode was more practical for quick acquisition while limiting the probability of operator error.

  19. The Translucent Cadaver: An Evaluation of the Use of Full Body Digital X-Ray Images and Drawings in Surface Anatomy Education

    Science.gov (United States)

    Kotze, Sanet Henriet; Mole, Calvin Gerald; Greyling, Linda Magdalena

    2012-01-01

    It has been noted by staff at the Faculty of Health Sciences, Stellenbosch University that medical students neglect the study of surface anatomy during dissection. This study reports on the novel use of Lodox[R] Statscan[R] images in anatomical education, particularly the teaching of surface anatomy. Full body digital X-ray images (Lodox Statscan)…

  20. Skull x-ray

    Science.gov (United States)

    X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  1. Neck x-ray

    Science.gov (United States)

    X-ray - neck; Cervical spine x-ray; Lateral neck x-ray ... There is low radiation exposure. X-rays are monitored so that the lowest amount of radiation is used to produce the image. Pregnant women and ...

  2. Pre-Columbian alloys from the royal tombs of Sipan; energy dispersive X-ray fluorescence analysis with a portable equipment

    Energy Technology Data Exchange (ETDEWEB)

    Cesareo, R. [Dip. di Matematica e Fisica, Universita di Sassari, via Vienna 2, 07100, Sassari (Italy)], E-mail: cesareo@uniss.it; Calza, C.; Dos Anjos, M.; Lopes, R.T. [Nuclear Instrumentation Laboratory, COPPE, Universidade Federal do Rio de Janeiro (Brazil); Bustamante, A.; Fabian S, J. [Universidad Nacional Mayor de San Marcos, Lima (Peru); Alva, W.; Chero Z, L. [Museo ' Tumbas Reales de Sipan' , Lambayeque (Peru)

    2010-04-15

    On the north coast of present-day Peru flourished approximately between 50 and 700 AD, the Moche civilization. It was an advanced culture and the Moche were sophisticated metalsmiths, so that they are considered as the finest producers of jewels and artefacts of the region. The Moche metalworking ability was impressively demonstrated by the objects discovered by Walter Alva and coworkers in 1987, in the excavations of the 'Tumbas Reales de Sipan'. About 50 metal objects from these excavations, now at the namesake Museum, in Lambayeque, north of Peru, were analyzed with a portable equipment using energy-dispersive X-ray fluorescence. This portable equipment is mainly composed of a small size X-ray tube and a thermoelectrically cooled X-ray detector. Standard samples of gold and silver alloys were employed for quantitative analysis. It was determined that the analyzed artefacts from the 'Tumbas Reales de Sipan' are mainly composed of gold, silver and copper alloys, of gilded copper and of tumbaga, the last being a poor gold alloy enriched at the surface by depletion gilding, i.e. removing copper from the surface.

  3. Pre-Columbian alloys from the royal tombs of Sipan; energy dispersive X-ray fluorescence analysis with a portable equipment

    International Nuclear Information System (INIS)

    Cesareo, R.; Calza, C.; Dos Anjos, M.; Lopes, R.T.; Bustamante, A.; Fabian S, J.; Alva, W.; Chero Z, L.

    2010-01-01

    On the north coast of present-day Peru flourished approximately between 50 and 700 AD, the Moche civilization. It was an advanced culture and the Moche were sophisticated metalsmiths, so that they are considered as the finest producers of jewels and artefacts of the region. The Moche metalworking ability was impressively demonstrated by the objects discovered by Walter Alva and coworkers in 1987, in the excavations of the 'Tumbas Reales de Sipan'. About 50 metal objects from these excavations, now at the namesake Museum, in Lambayeque, north of Peru, were analyzed with a portable equipment using energy-dispersive X-ray fluorescence. This portable equipment is mainly composed of a small size X-ray tube and a thermoelectrically cooled X-ray detector. Standard samples of gold and silver alloys were employed for quantitative analysis. It was determined that the analyzed artefacts from the 'Tumbas Reales de Sipan' are mainly composed of gold, silver and copper alloys, of gilded copper and of tumbaga, the last being a poor gold alloy enriched at the surface by depletion gilding, i.e. removing copper from the surface.

  4. Pre-Columbian alloys from the royal tombs of Sipán; energy dispersive X-ray fluorescence analysis with a portable equipment.

    Science.gov (United States)

    Cesareo, R; Calza, C; Dos Anjos, M; Lopes, R T; Bustamante, A; Fabian S, J; Alva, W; Chero Z, L

    2010-01-01

    On the north coast of present-day Peru flourished approximately between 50 and 700 AD, the Moche civilization. It was an advanced culture and the Moche were sophisticated metalsmiths, so that they are considered as the finest producers of jewels and artefacts of the region. The Moche metalworking ability was impressively demonstrated by the objects discovered by Walter Alva and coworkers in 1987, in the excavations of the "Tumbas Reales de Sipán". About 50 metal objects from these excavations, now at the namesake Museum, in Lambayeque, north of Peru, were analyzed with a portable equipment using energy-dispersive X-ray fluorescence. This portable equipment is mainly composed of a small size X-ray tube and a thermoelectrically cooled X-ray detector. Standard samples of gold and silver alloys were employed for quantitative analysis. It was determined that the analyzed artefacts from the "Tumbas Reales de Sipán" are mainly composed of gold, silver and copper alloys, of gilded copper and of tumbaga, the last being a poor gold alloy enriched at the surface by depletion gilding, i.e. removing copper from the surface. Copyright 2009 Elsevier Ltd. All rights reserved.

  5. Digital x-ray tomosynthesis with interpolated projection data for thin slab objects

    Science.gov (United States)

    Ha, S.; Yun, J.; Kim, H. K.

    2017-11-01

    In relation with a thin slab-object inspection, we propose a digital tomosynthesis reconstruction with fewer numbers of measured projections in combinations with additional virtual projections, which are produced by interpolating the measured projections. Hence we can reconstruct tomographic images with less few-view artifacts. The projection interpolation assumes that variations in cone-beam ray path-lengths through an object are negligible and the object is rigid. The interpolation is performed in the projection-space domain. Pixel values in the interpolated projection are the weighted sum of pixel values of the measured projections considering their projection angles. The experimental simulation shows that the proposed method can enhance the contrast-to-noise performance in reconstructed images while sacrificing the spatial resolving power.

  6. X-ray imaging using amorphous selenium: photoinduced discharge (PID) readout for digital general radiography.

    Science.gov (United States)

    Rowlands, J A; Hunter, D M

    1995-12-01

    Digital radiographic systems based on photoconductive layers with the latent charge image readout by photoinduced discharge (PID) are investigated theoretically. Previously, a number of different systems have been proposed using sandwiched photoconductor and insulator layers and readout using a scanning laser beam. These systems are shown to have the general property of being very closely coupled (i.e., optimization of one imaging characteristic usually impacts negatively on others). The presence of a condensed state insulator between the photoconductor surface and the readout electrode does, however, confer a great advantage over systems using air gaps with their relatively low breakdown field. The greater breakdown field of condensed state dielectrics permits the modification of the electric field during the period between image formation and image readout. The trade-off between readout speed and noise makes this system suitable for instant general radiography and even rapid sequence radiography, however, the system is unsuitable for the low exposure rates used in fluoroscopy.

  7. Fully automated joint space width measurement and digital X-ray radiogrammetry in early RA.

    Science.gov (United States)

    Platten, Michael; Kisten, Yogan; Kälvesten, Johan; Arnaud, Laurent; Forslind, Kristina; van Vollenhoven, Ronald

    2017-01-01

    To study fully automated digital joint space width (JSW) and bone mineral density (BMD) in relation to a conventional radiographic scoring method in early rheumatoid arthritis (eRA). Radiographs scored by the modified Sharp van der Heijde score (SHS) in patients with eRA were acquired from the SWEdish FarmacOTherapy study. Fully automated JSW measurements of bilateral metacarpals 2, 3 and 4 were compared with the joint space narrowing (JSN) score in SHS. Multilevel mixed model statistics were applied to calculate the significance of the association between ΔJSW and ΔBMD over 1 year, and the JSW differences between damaged and undamaged joints as evaluated by the JSN. Based on 576 joints of 96 patients with eRA, a significant reduction from baseline to 1 year was observed in the JSW from 1.69 (±0.19) mm to 1.66 (±0.19) mm (p0) joints: 1.68 mm (95% CI 1.70 to 1.67) vs 1.54 mm (95% CI 1.63 to 1.46). Similarly the unadjusted multilevel model showed significant differences in JSW between undamaged (1.68 mm (95% CI 1.72 to 1.64)) and damaged joints (1.63 mm (95% CI 1.68 to 1.58)) (p=0.0048). This difference remained significant in the adjusted model: 1.66 mm (95% CI 1.70 to 1.61) vs 1.62 mm (95% CI 1.68 to 1.56) (p=0.042). To measure the JSW with this fully automated digital tool may be useful as a quick and observer-independent application for evaluating cartilage damage in eRA. NCT00764725.

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

    International Nuclear Information System (INIS)

    Kishimoto, M.; Sumiya, T.; Lee, K.J.

    2010-01-01

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

  9. Image guided radiotherapy. Quality control of X ray equipment. S.F.P.M. report nr 29

    International Nuclear Information System (INIS)

    Delpon, Gregory; Aubignac, Leone; Bramoulle, Celine; Boutry, Christine; Guerin, Lucie; Lafay, Frederic; Benoit, David; Garcia, Robin; Jaegle, Enric; Vieillevigne, Laure; Dedieu, Veronique; Ferrrer, Ludovic; Guillhem, Marie-Therese; Lacaze, Brigitte; Mazurier, Jocelyne; Simon, Luc

    2014-01-01

    This report presents different X ray imagery systems used for positioning support in external radiation therapy, and installed in treatment rooms. If portal imagery systems and rail-mounted tomodensitometry systems are not addressed in this document, the authors distinguish and describe various embedded systems in which devices are directly mounted on the treatment apparatus (X-Ray Volume Imaging by Elekta, On Board Imager by Varian), peripheral systems which are independent from the machine (Cyberknife by Accuray and Exatrac by BrainLab), MVCT or Mega Voltage Computed Tomography systems (Tomotherapy by Accuray), and MVCBCT or Megavoltage Cone Beam Computed Tomography systems (Artiste by Siemens). After a brief presentation of these systems, the author present various aspects of quality controls (list, periodicity, test tolerance, tested objects), and then more precisely describe the above-mentioned systems. For each of them, the following aspects are addressed: generator, geometry, image quality, dose, environment and safety, gating module, quality controls

  10. Mapping soil deformation around plant roots using in vivo 4D X-ray Computed Tomography and Digital Volume Correlation.

    Science.gov (United States)

    Keyes, S D; Gillard, F; Soper, N; Mavrogordato, M N; Sinclair, I; Roose, T

    2016-06-14

    The mechanical impedance of soils inhibits the growth of plant roots, often being the most significant physical limitation to root system development. Non-invasive imaging techniques have recently been used to investigate the development of root system architecture over time, but the relationship with soil deformation is usually neglected. Correlative mapping approaches parameterised using 2D and 3D image data have recently gained prominence for quantifying physical deformation in composite materials including fibre-reinforced polymers and trabecular bone. Digital Image Correlation (DIC) and Digital Volume Correlation (DVC) are computational techniques which use the inherent material texture of surfaces and volumes, captured using imaging techniques, to map full-field deformation components in samples during physical loading. Here we develop an experimental assay and methodology for four-dimensional, in vivo X-ray Computed Tomography (XCT) and apply a Digital Volume Correlation (DVC) approach to the data to quantify deformation. The method is validated for a field-derived soil under conditions of uniaxial compression, and a calibration study is used to quantify thresholds of displacement and strain measurement. The validated and calibrated approach is then demonstrated for an in vivo test case in which an extending maize root in field-derived soil was imaged hourly using XCT over a growth period of 19h. This allowed full-field soil deformation data and 3D root tip dynamics to be quantified in parallel for the first time. This fusion of methods paves the way for comparative studies of contrasting soils and plant genotypes, improving our understanding of the fundamental mechanical processes which influence root system development. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. 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 ...

  12. Analysis of the influence of aliasing effect on the digital X ray images

    International Nuclear Information System (INIS)

    Niu Yantao; Liu Zhensheng; Wang Gexin; Zhao Bo; Hao Hui; Yan Shulin

    2007-01-01

    Objective: To investigate the causes and eliminating methods of aliasing effect in digital radiography. Methods: Stationary grid and rectangular wave test phantom were imaged on Kodak CR900 system. Lead strips of phantom were parallel to laser scanning direction or with an angle of 45 degrees when they were exposed on imaging plate. The representation ability for resolution test phantom in two types of images were observed. Grid was imaged when its lead strips are parallel to or perpendicular to laser scanning direction. Two images were observed and contrasted on monitor using various magnifying rate. Results: In phantom images, the lead bats below the frequency of 3.93 linepairs per mm could be discriminated, and it is Nyquist frequency of this system. But the lead bars with the frequency of 4.86 linepairs per mm could even been distinguished in the image of test phantom with an angle of 45 degrees. When grid lead bars were parallel to imaging plate scanning direction, resulting images displayed visable streak artifacts. The display degree has marked difference when grid strips were parallel or perpendicular to laser scanning direction. Streaks were not clear when the image was displayed as true size on monitor, but there widths changed in a large range as zoom in or zoom out. At the same time, the directions of streaks changed. Conclusions: Optimum stationary grids should be selected in clinical practice according to limited resolution of CR system because aliasing effect would cause disadvantageous influence, and grid frequency should be greater than Nyquist frequency. Grid strip direction should be perpendicular to laser scanner direction in clinics to avoid streak artifacts. There are notable affection to image seeming on monitor when using different magnifying rate, and using integral times of real image size were suggested. (authors)

  13. 50 μm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis.

    Science.gov (United States)

    Zhao, C; Konstantinidis, A C; Zheng, Y; Anaxagoras, T; Speller, R D; Kanicki, J

    2015-12-07

    Wafer-scale CMOS active pixel sensors (APSs) have been developed recently for x-ray imaging applications. The small pixel pitch and low noise are very promising properties for medical imaging applications such as digital breast tomosynthesis (DBT). In this work, we evaluated experimentally and through modeling the imaging properties of a 50 μm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). A modified cascaded system model was developed for CMOS APS x-ray detectors by taking into account the device nonlinear signal and noise properties. The imaging properties such as modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) were extracted from both measurements and the nonlinear cascaded system analysis. The results show that the DynAMITe x-ray detector achieves a high spatial resolution of 10 mm(-1) and a DQE of around 0.5 at spatial frequencies  CMOS APS x-ray detector, image aquisition geometry and image reconstruction techniques should be considered.

  14. Candidate isolated neutron stars and other optically blank x-ray fields identified from the rosat all-sky and sloan digital sky surveys

    Energy Technology Data Exchange (ETDEWEB)

    Agueros, Marcel A.; Anderson, Scott F.; /Washington U., Seattle, Astron. Dept.; Margon, Bruce; /Baltimore, Space Telescope Sci.; Haberl, Frank; Voges, Wolfgang; /Garching,; Annis, James; /Fermilab; Schneider, Donald P.; /Penn State U., Astron. Astrophys.; Brinkmann, Jonathan; /Apache Point Observ.

    2005-11-01

    Only seven radio-quiet isolated neutron stars (INSs) emitting thermal X rays are known, a sample that has yet to definitively address such fundamental issues as the equation of state of degenerate neutron matter. We describe a selection algorithm based on a cross-correlation of the ROSAT All-Sky Survey (RASS) and the Sloan Digital Sky Survey (SDSS) that identifies X-ray error circles devoid of plausible optical counterparts to the SDSS g {approx} 22 magnitudes limit. We quantitatively characterize these error circles as optically blank; they may host INSs or other similarly exotic X-ray sources such as radio-quiet BL Lacs, obscured AGN, etc. Our search is an order of magnitude more selective than previous searches for optically blank RASS error circles, and excludes the 99.9% of error circles that contain more common X-ray-emitting subclasses. We find 11 candidates, nine of which are new. While our search is designed to find the best INS candidates and not to produce a complete list of INSs in the RASS, it is reassuring that our number of candidates is consistent with predictions from INS population models. Further X-ray observations will obtain pinpoint positions and determine whether these sources are entirely optically blank at g {approx} 22, supporting the presence of likely isolated neutron stars and perhaps enabling detailed follow-up studies of neutron star physics.

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

    Science.gov (United States)

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

    2017-09-01

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

  16. A digital X-ray imaging system based on silicon strip detectors working in edge-on configuration

    Energy Technology Data Exchange (ETDEWEB)

    Bolanos, L. [CEADEN, Calle 30 502 e/ 5ta y 7ma Avenida, Playa, Ciudad Habana (Cuba); Boscardin, M. [IRST, Fondazione Bruno Kessler, Via Sommarive 18, Povo, 38100 Trento (Italy); Cabal, A.E. [CEADEN, Calle 30 502 e/ 5ta y 7ma Avenida, Playa, Ciudad Habana (Cuba); Diaz, M. [InSTEC, Ave. Salvador Allende esq. Luaces, Quinta de los Molinos, Ciudad Habana (Cuba); Grybos, P.; Maj, P. [Faculty of Electrical Engineering, Automatics, Computer Science and Electronics, Department of Measurement and Instrumentation, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Prino, F. [Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via P. Giuria 1, 10125 Torino (Italy); Ramello, L. [Dipartimento di Scienze e Tecnologie Avanzate, Universita del Piemonte Orientale, Via T. Michel 11, 15100 Alessandria (Italy)], E-mail: luciano.ramello@mfn.unipmn.it; Szczygiel, R. [Faculty of Electrical Engineering, Automatics, Computer Science and Electronics, Department of Measurement and Instrumentation, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland)

    2009-09-21

    We present the energy resolution and imaging performance of a digital X-ray imaging system based on a 512-strip silicon strip detector (SSD) working in the edge-on configuration. The SSDs tested in the system are 300 {mu}m thick with 1 or 2-cm-long strips and 100 {mu}m pitch. To ensure a very small dead area of the SSD working in edge-on configuration, the detector is cut perpendicular to the strips at a distance of only 20 {mu}m from the end of the strips. The 512-strip silicon detector is read out by eight 64-channel integrated circuits called DEDIX [Grybos et al., IEEE Trans. Nucl. Sci. NS-54 (2007) 1207]. The DEDIX IC operates in a single photon counting mode with two independent amplitude discriminators per channel. The readout electronic channel connected to a detector with effective input capacitance of about 2 pF has an average equivalent noise charge (ENC) of about 163 el. rms and is able to count 1 Mcps of average rate of input pulses. The system consisting of 512 channels has an excellent channel-to-channel uniformity-the effective threshold spread calculated to the charge-sensitive amplifier inputs is 12 el. rms (at one sigma level). With this system a few test images of a phantom have been taken in the 10-30 keV energy range.

  17. Small Field of View Scintimammography Gamma Camera Integrated to a Stereotactic Core Biopsy Digital X-ray System

    Energy Technology Data Exchange (ETDEWEB)

    Andrew Weisenberger; Fernando Barbosa; T. D. Green; R. Hoefer; Cynthia Keppel; Brian Kross; Stanislaw Majewski; Vladimir Popov; Randolph Wojcik

    2002-10-01

    A small field of view gamma camera has been developed for integration with a commercial stereotactic core biopsy system. The goal is to develop and implement a dual-modality imaging system utilizing scintimammography and digital radiography to evaluate the reliability of scintimammography in predicting the malignancy of suspected breast lesions from conventional X-ray mammography. The scintimammography gamma camera is a custom-built mini gamma camera with an active area of 5.3 cm /spl times/ 5.3 cm and is based on a 2 /spl times/ 2 array of Hamamatsu R7600-C8 position-sensitive photomultiplier tubes. The spatial resolution of the gamma camera at the collimator surface is < 4 mm full-width at half-maximum and a sensitivity of /spl sim/ 4000 Hz/mCi. The system is also capable of acquiring dynamic scintimammographic data to allow for dynamic uptake studies. Sample images of preliminary clinical results are presented to demonstrate the performance of the system.

  18. Experimental investigation for determination of optimal X-ray beam tube voltages in a newly developed digital breast tomosynthesis system

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hye-Suk, E-mail: radiosugar@yonsei.ac.kr [Department of Radiological Science and Research Institute of Health Science, Yonsei University, Wonju, Gangwon 220-710 (Korea, Republic of); Kim, Ye-Seul, E-mail: radiohesugar@gmail.com [Department of Radiological Science and Research Institute of Health Science, Yonsei University, Wonju, Gangwon 220-710 (Korea, Republic of); Choi, Young-Wook, E-mail: ywchoi@keri.re.kr [Korea Electrotechnology Research Institute (KERI), Ansan, Geongki 426-170 (Korea, Republic of); Choi, JaeGu, E-mail: jgchoi88@paran.com [Korea Electrotechnology Research Institute (KERI), Ansan, Geongki 426-170 (Korea, Republic of); Rhee, Yong-Chun, E-mail: ycrhee@yonsei.ac.kr [Department of Radiological Science and Research Institute of Health Science, Yonsei University, Wonju, Gangwon 220-710 (Korea, Republic of); Kim, Hee-Joung, E-mail: hjk1@yonsei.ac.kr [Department of Radiological Science and Research Institute of Health Science, Yonsei University, Wonju, Gangwon 220-710 (Korea, Republic of)

    2014-11-01

    Our purpose was to investigate optimal tube voltages (kVp) for a newly developed digital breast tomosynthesis (DBT) process and to determine tube current–exposure time products (mA s) for the average glandular dose (AGD), which is similar to that of the two views in conventional mammography (CM). In addition, the optimal acquisition parameters for this system were compared with those of CM. The analysis was based on the contrast-to-noise ratio (CNR) from the simulated micro-calcifications on homogeneous phantoms, and the figure of merit (FOM) was retrieved from the CNR and AGD at X-ray tube voltages ranging from 24 to 40 kVp at intervals of 2 kV. The optimal kVp increased more than 2 kV with increasing glandularity for thicker (≥50 mm) breast phantoms. The optimal kVp for DBT was found to be 4–7 kV higher than that calculated for CM with breast phantoms thicker than 50 mm. This is likely due to the greater effect of noise and dose reduction by kVp increment when using the lower dose per projection in DBT. It is important to determine optimum acquisition conditions for a maximally effective DBT system. The results of our study provide useful information to further improve DBT for high quality imaging.

  19. Morphological evolution and internal strain mapping of pomelo peel using X-ray computed tomography and digital volume correlation

    KAUST Repository

    Wang, B.

    2017-10-15

    Cellular microstructures within natural materials enlighten and promote the development of novel materials and structures in the industrial and engineering fields. Characterization of the microstructures and mechanical properties of these natural materials can help to understand the morphology-related mechanical properties and guide the structural optimization in industrial design. Among these natural cellular materials, pomelo peels, having a foam-like hierarchical microstructure, represent an ideal model for developing materials with high energy absorption efficiency. In this work, by combining X-ray tomographic imaging technique and digital volume correlation (DVC), in-situ stepwise uniaxial compression tests were performed to quantify the internal morphological evolution and kinematic responses of pomelo peel samples during compression. Via these experiments, the varying microstructure features and thus diverse resistance to compression from endocarp to exocarp are examined, and the evolution of both bundles bending and large strain domain from endocarp to mesocarp are explored. Based on the experimental results, the microstructure-related mechanical properties of pomelo peels in response to compressive loading that demonstrates nearly linear morphology-mechanics relationship were revealed.

  20. X-ray induced formation of γ-H2AX foci after full-field digital mammography and digital breast-tomosynthesis.

    Directory of Open Access Journals (Sweden)

    Siegfried A Schwab

    Full Text Available PURPOSE: To determine in-vivo formation of x-ray induced γ-H2AX foci in systemic blood lymphocytes of patients undergoing full-field digital mammography (FFDM and to estimate foci after FFDM and digital breast-tomosynthesis (DBT using a biological phantom model. MATERIALS AND METHODS: The study complies with the Declaration of Helsinki and was performed following approval by the ethic committee of the University of Erlangen-Nuremberg. Written informed consent was obtained from every patient. For in-vivo tests, systemic blood lymphocytes were obtained from 20 patients before and after FFDM. In order to compare in-vivo post-exposure with pre-exposure foci levels, the Wilcoxon matched pairs test was used. For in-vitro experiments, isolated blood lymphocytes from healthy volunteers were irradiated at skin and glandular level of a porcine breast using FFDM and DBT. Cells were stained against the phosphorylated histone variant γ-H2AX, and foci representing distinct DNA damages were quantified. RESULTS: Median in-vivo foci level/cell was 0.086 (range 0.067-0.116 before and 0.094 (0.076-0.126 after FFDM (p = 0.0004. In the in-vitro model, the median x-ray induced foci level/cell after FFDM was 0.120 (range 0.086-0.140 at skin level and 0.035 (range 0.030-0.050 at glandular level. After DBT, the median x-ray induced foci level/cell was 0.061 (range 0.040-0.081 at skin level and 0.015 (range 0.006-0.020 at glandular level. CONCLUSION: In patients, mammography induces a slight but significant increase of γ-H2AX foci in systemic blood lymphocytes. The introduced biological phantom model is suitable for the estimation of x-ray induced DNA damages in breast tissue in different breast imaging techniques.

  1. Evaluating performance characteristics of x-ray equipment and film systems without the use of electronic measurement and/or special instruments

    International Nuclear Information System (INIS)

    Bianchi, M.F.; DeNitto, C.; Liscio, A.; Scala, N.

    2004-01-01

    Measurement and control of characteristics of NDT equipment and system that produce output to be interpreted by inspector is one of the most important tools for NDT reliability. Control activity should be based on: initial accurate measurement and calibration; periodical check to assure maintenance of calibration status; and, immediate verification and corrective action when any malfunctioning is suspected. 'Self-calibration' intended as capability of NDT facility to calibrate and control its own equipment and systems is very important for continuous and reliable activity. Typical approach based on this philosophy is ASTM E317 'Standard Practice for Evaluating Performance Characteristics of Ultrasonic Pulse-Echo Examination Instruments and Systems Without the Use of Electronic Measurement Instruments' that is applicable to shop or field conditions. Is 'Self-calibration' applicable to radiographic system too? Many characteristics can be self-determined according to existing practices and methods, but other ones require assistance and cooperation of supplier both for film system and x-ray equipment. A certified film system being controlled by pre-exposed filmstrips can be adopted as 'measurement device' for X-ray output concerning both intensity and contrast. Basically x-ray equipment manufacturer performs initial accurate measurement and calibration using electronic measurement and/or special instrumentation as necessary. Then specific film set on 'low-price' blocks and specimens is produced according to standard practice whose guidelines are supplied by this paper. Film set, blocks, specimens and results referred to specific film system will be the reference kit for periodical check in NDT facility. This paper supplies some guidelines for standard practice based on testing using mainly GE Inspection Technologies radiographic system being available in Avio facilities. (author)

  2. Licensing of non intrusive inspection equipment s for load and passengers vehicles that use X rays with energies up to 9 MeV. Mexican experience

    International Nuclear Information System (INIS)

    Munoz M, G. A.; Jimenez C, I.

    2013-10-01

    In the last years and like part of the extensive program of national security, in Mexico have been introduced a great quantity of non intrusive inspection equipment s for load and passengers vehicles that use X rays up to 9 MeV. Due to the great variety of equipment s, the Comision Nacional de Seguridad Nuclear y Salvaguardias (Mexican regulator organ) has established specific guidelines for their licensing and use supervision. In this work the adopted guidelines are exposed in the technical and administrative evaluation for the later licensing of these equipment s. Relative particular questions to the site of these equipment s and the impact in the public opinion that their use can generate are discussed. (author)

  3. Developments in digital radiography: an equipment update

    International Nuclear Information System (INIS)

    James, J.J.; O'Connor, P.J.; Davies, A.G.; Cowen, A.R.

    2001-01-01

    Digital X-ray imaging technology has advanced rapidly over the past few years. This review, particularly aimed at those involved in using and purchasing such technology, is an attempt to unravel some of the complexities of this potentially confusing subject. The main groups of X-ray imaging devices that are considered are digitisers of conventional radiographs, image-intensifier-based fluorography systems, photostimulable phosphor computed radiography, amorphous selenium-based technology for thorax imaging and flat-panel systems. As well as describing these different systems, we look at ways of objectively assessing their image quality. Concepts that are used and explained include spatial resolution, grey-scale bit resolution, signal-to-noise ratio and detective quantum efficiency. An understanding of these basic parameters is vital in making a scientific assessment of a system's performance. Image processing and techniques are also briefly discussed, particularly with reference to their potential effects on image quality. This review aims to provide a basic understanding of digital X-ray imaging technology and enables the reader to make an independent and educated assessment of the relative merits of each system. (orig.)

  4. Compaction bands in shale revealed through digital volume correlation of time-resolved X-ray tomography scans

    Science.gov (United States)

    McBeck, J.; Kobchenko, M.; Hall, S.; Tudisco, E.; Cordonnier, B.; Renard, F.

    2017-12-01

    Previous studies have identified compaction bands primarily within sandstones, and in fewer instances, within other porous rocks and sediments. Using Digital Volume Correlation (DVC) of X-ray microtomography scans, we find evidence of localized zones of high axial contraction that form tabular structures sub-perpendicular to maximum compression, σ1, in Green River shale. To capture in situ strain localization throughout loading, two shale cores were deformed in the HADES triaxial deformation apparatus installed on the X-ray microtomography beamline ID19 at the European Synchrotron Radiation Facility. In these experiments, we increase σ1 in increments of two MPa, with constant confining pressure (20 MPa), until the sample fails in macroscopic shear. After each stress step, a 3D image of the sample inside the rig is acquired at a voxel resolution of 6.5 μm. The evolution of lower density regions within 3D reconstructions of linear attenuation coefficients reveal the development of fractures that fail with some opening. If a fracture produces negligible dilation, it may remain undetected in image segmentation of the reconstructions. We use the DVC software TomoWarp2 to identify undetected fractures and capture the 3D incremental displacement field between each successive pair of microtomography scans acquired in each experiment. The corresponding strain fields reveal localized bands of high axial contraction that host minimal shear strain, and thus match the kinematic definition of compaction bands. The bands develop sub-perpendicular to σ1 in the two samples in which pre-existing bedding laminations were oriented parallel and perpendicular to σ1. As the shales deform plastically toward macroscopic shear failure, the number of bands and axial contraction within the bands increase, while the spacing between the bands decreases. Compaction band development accelerates the rate of overall axial contraction, increasing the mean axial contraction throughout the sample

  5. A new implementation of digital X-ray radiogrammetry and reference curves of four indices of cortical bone for healthy European adults

    DEFF Research Database (Denmark)

    Thodberg, Hans Henrik; Böttcher, Joachim; Lomholt, Jens

    2016-01-01

    UNLABELLED: Digital X-ray radiogrammetry performs measurements on a hand radiograph in digital form. We present an improved implementation of the method and provide reference curves for four indices for the amount of bone. We collected 1662 hand radiographs of healthy subjects of age 9-100 years....... PURPOSE: The digital X-ray radiogrammetry (DXR) method has been shown to be efficient for diagnosis of osteoporosis and for assessment of progression of rheumatoid arthritis. The aim of this work is to present a new DXR implementation and reference curves of four indices of cortical bone and to compare...... their relative SDs in healthy subjects at fixed age and gender. MATERIALS AND METHODS: A total of 1662 hand radiographs of healthy subjects of age 9-100 years were collected in Jena in 2001-2005. We also used a longitudinal study of 116 Danish children born in 1952 with on average 11 images taken over the age...

  6. Medical x-ray

    International Nuclear Information System (INIS)

    Abd Aziz Mhd Ramli; Gui Ah Auu; Husaini Salleh; Idris Besar; Mohd Ashhar Khalid; Muhammad Jamal Md Isa; Shaharuddin Mohd; Siti Najila Mohd Janib; Mohamed Ali Abdul Khader; Mahalatchimi Dave; Mohd Fazly Abdul Rahim; Ng Chee Moon; Ram Piari; Teoh Hoon Heng; Lee Peter

    2004-01-01

    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

  7. Case study of a traditional material (adobe) for facilities design destined to X-ray equipment emplacement

    International Nuclear Information System (INIS)

    Aguilar Serrano, Lola

    2008-01-01

    The objective of this work is to use the existent material (adobe) in the national market as an alternative for an optimum design that counts with the conditions for radiological protection as well as an adequate infrastructure to service assistance. Therefore, it gives a tool of professional use for an X-ray installation design, because the adobes represent an adequate protection for employees as Worker occupational exposed (WOE) and for general public, also for economics reasons and construction technical aspects. With the study of above material is demonstrated that in X-ray facilities construction is not always necessary the use of lead sheets or another materials for walls, which are used as shielding elements against ionizing radiation. The adobe election for this study, is because Bolivia counts with a great percentage of constructed areas whit this type of material because is economical and raw material is accessible for users. From the experimental tests we get the graphics that allow to found the half value thickness (HVT) of the half layer (HVL) of this adobe, is that thickness of material with when placed in the path of the radiation will attenuate it to one half its original value. A tenth value thickness (TVT) similarly reduces the radiation to one tenth of its original value. Material which contains heavy atoms and molecules such as steel and lead provide the most effective (thinnest) shields for X-rays. The contribute of this study, carried out with the construction material (adobe) that exists in the national market will be of great utility for society because there is no values recorded in the bibliography. (author)

  8. X-ray equipment for dental diagnostics with a dose-rate controller influencing the exposure voltage

    International Nuclear Information System (INIS)

    Franke, K.

    1980-01-01

    If a synoptic picture is taken of teeth or jaw the X-ray tube and the film carrier with the film and a radiation detector are moving around the patient's head. The detector signal is connected to the input of the actual value of the dose-rate controller containing a scanning and stop circuit with a storing time roughly corresponding to the exposure of three teeth. After the shot the actual value of the dose rate is adjusted to the desired value, thus a constant quality of the following pictures being achieved. (RW) [de

  9. Results of the technical evaluation of dentistry X-ray equipment of a faculty of Dentistry of Rio Grande do Sul State, based on Regulation 453 of Health Ministry and IRD/CNEN-BR recommendations

    International Nuclear Information System (INIS)

    Staevie, G.L.G.; Jahn, T.R.; Barbieri, D.X.; Mas, C.R Dal; Sbaraini, P.; Saba, J.C.P.

    2001-01-01

    This paper describes the technical evaluation of odontology X-ray equipment installed in a local school of odontology with regard to the fulfillment of requirements of Regulation No. 453, issued by Brazilian Ministry of Health and the recommendations of the Institute of Radiation Protection and Dosimetry, IRD/CNEN. Fifteen intra-oral odontology X-ray equipment were evaluated and their conformities and non-conformities were identified, followed by recommendations to be adopted by the school. (author)

  10. Russian medical X-ray engineering is confidently going into the year 2000

    International Nuclear Information System (INIS)

    Chikirdin, Eh.G.

    2000-01-01

    The achievements of the national medical X-ray technique are analyzed on the basis of the materials of the International exhibition Public health-99 which took place in November-December 1999, are analyzed. Great attention of the enterprises-developers was paid to fluorographic-digital equipment due to actuality of the lungs tuberculosis control in Russia. The characteristics for several fluorographic digital facilities, wherein by high technical characteristics it proves possible to improve the design and obtain low radiation doses for the patients and sufficiently low cost of the equipment, are presented. The characteristics of mobile facilities for X-ray diagnostics, including a fluorograph, mammograph, dental X-ray apparatus, are also presented. The attention was also paid to a X-ray diagnostic complex, feed devices, phantom sets, tomograph, dental apparatus and other developments in the area of X-ray technique. The outlooks for developments in the area of the national medical Xray technique are noted [ru

  11. Time- and wavelength-resolved luminescence evaluation of several types of scintillators using streak camera system equipped with pulsed X-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Furuya, Yuki, E-mail: f.yuki@mail.tagen.tohoku.ac.j [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Yanagida, Takayuki; Fujimoto, Yutaka; Yokota, Yuui; Kamada, Kei [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Kawaguchi, Noriaki [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Research and Development Division, Tokuyama., Co. Ltd., ICR-Building, Minamiyoshinari, Aoba-ku, Sendai (Japan); Ishizu, Sumito [Research and Development Division, Tokuyama., Co. Ltd., ICR-Building, Minamiyoshinari, Aoba-ku, Sendai (Japan); Uchiyama, Koro; Mori, Kuniyoshi [Hamamatsu Photonics K.K., 325-6, Sunayama-cho, Naka-ku, Hamamatsu, Shizuoka 430-8587 (Japan); Kitano, Ken [Vacuum and Optical Instruments, 2-18-18 Shimomaruko, Ota, Tokyo 146-0092 (Japan); Nikl, Martin [Institute of Physics ASCR, Cukrovarnicka 10, Prague 6, 162-53 (Czech Republic); Yoshikawa, Akira [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); NICHe, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan)

    2011-04-01

    To design new scintillating materials, it is very important to understand detailed information about the events, which occurred during the excitation and emission processes under the ionizing radiation excitation. We developed a streak camera system equipped with picosecond pulsed X-ray source to observe time- and wavelength-resolved scintillation events. In this report, we test the performance of this new system using several types of scintillators including bulk oxide/halide crystals, transparent ceramics, plastics and powders. For all samples, the results were consistent with those reported previously. The results demonstrated that the developed system is suitable for evaluation of the scintillation properties.

  12. Clinical evaluation of digital angiographic system equipped with the Safire' flat-panel detector of a direct conversion type

    International Nuclear Information System (INIS)

    Miura, Yoshiaki; Miura, Yusuke; Goto, Keiichi

    2003-01-01

    This report presents a report on clinical evaluation of our newly developed flat-panel X-ray detector of a direct conversion type, designed to provide images of a resolution higher than, or at least equal to, that ensured by X-ray photographic films, in clinical digital X-ray cinematography. This new detector was named 'Safire' the acronym of 'Shimadzu advanced flat imaging receptor', emphasizing its high technological level, such as the capability to ensure high quality of images. The clinical evaluation of Shimadzu DIGITEX Premier digital angiography system, equipped with this new flat-panel X-ray detector of a direct conversion type, has been started in March, 2003, at the Kokura Memorial Hospital in Kyushu, Japan. (author)

  13. 171 ROYAL DECREE 1891/1991 of 30 December 1991 on the installation and use of X-ray equipment for the purposes of medical diagnosis

    International Nuclear Information System (INIS)

    1992-01-01

    The Decree lays down the rules enabling government authorities to monitor the proper functioning of such appliances. It takes account of the Council of European Communities' Directive 80/836/Euratom amended by Directive 84/466/Euratom on basic safety standards for the health protection of the general public and workers against the dangers of ionization and Directive 84/467/Euratom laying down basic measures for the radiation protection of persons undergoing medical examination or treatment. The Decree provides for a register of firms authorised to sell and maintain medical X-ray equipment, and a register of the equipment installed. It also sets out requirements relating to third party liability insurance, and to the qualifications and training of personnel operating the equipment. (NEA)

  14. X-ray diffraction

    International Nuclear Information System (INIS)

    Vries, J.L. de.

    1976-01-01

    The seventh edition of Philips' Review of literature on X-ray diffraction begins with a list of conference proceedings on the subject, organised by the Philips' organisation at regular intervals in various European countries. This is followed by a list of bulletins. The bibliography is divided according to the equipment (cameras, diffractometers, monochromators) and its applications. The applications are subdivided into sections for high/low temperature and pressure, effects due to the equipment, small angle scattering and a part for stress, texture and phase analyses of metals and quantitative analysis of minerals

  15. X-ray microtomography

    International Nuclear Information System (INIS)

    Dunsmuir, J.H.; Ferguson, S.R.; D'Amico, K.L.; Stokes, J.P.

    1991-01-01

    In this paper the authors describe the application of a new high-resolution X-ray tomographic microscope to the study of porous media. The microscope was designed to exploit the properties of a synchrotron X-ray source to perform three dimensional tomography on millimeter sized objects with micron resolution and has been used in materials science studies with both synchrotron and conventional and synchrotron sources will be compared. In this work the authors have applied the microscope to measure the three dimensional structure of fused bead packs and berea sandstones with micron resolution and have performed preliminary studies of flow in these media with the microscope operated in a digital subtraction radiography mode. Computer graphics techniques have been applied to the data to visually display the structure of the pore body system. Tomographic imaging after flow experiments should detect the structure of the oil-water interface in the pore network and this work is ongoing

  16. Local liquid velocity measurement in trickle bed reactors (TBRs) using the x-ray digital industrial radiography (DIR) technique

    Science.gov (United States)

    Anuar Mohd Salleh, Khairul; Lee, Hyoung Koo; Al-Dahhan, Muthanna H.

    2014-01-01

    This work describes the development of a new technique to measure local liquid velocity (VLL) for multiphase flows in trickle bed reactors (TBRs) (gas-liquid-solid system). In the studied TBR, the liquid phase is represented by water, gas by air and 3 mm expanded polystyrene beads as the solid packing. Three different superficial liquid velocities (VSL) and a constant superficial gas velocity (VSG) were used in the packed bed with an internal diameter of 4.25 cm. While the liquid is moving into the packed bed, tracking particles of 106-125 μm diameter (16.45% difference) are injected. The movement of the tracking particles is monitored and digitally recorded by a complementary metal-oxide-semiconductor detector. In this experiment, x-rays were used as the radiation source. Four replications were made with fresh packing. Comparable observations can be found from other published techniques (i.e. magnetic resonance imaging). Results from this study indicate that, at VSL = 0.13 cm s-1, the measured VLL can reach up to 51 times that of its VSL, while for VSL = 0.27 cm s-1, the measured VLL reached up to 35 times higher than the VSL and for VSL = 0.39 cm s-1, the VLL reached up to 39.8 times higher than its VSL. Through statistical analysis, the implementation of such a method is found to be reproducible throughout the experiments. The mean per cent difference in the measured VLL was 10% and 5% for lower implemented VSL of 0.13 and 0.27 cm s-1, respectively. At higher VSL (0.39 cm s-1), the particle tracer was greatly distributed and carried away by the high liquid flow rate. The variance or the range of the measured VLL does not vary for all replications in every VSL, which confirms the reproducibility of the experimental measurements, regardless of the VSL.

  17. Evaluation of bone-mineral density by digital X-ray radiogrammetry (DXR) in pediatric renal transplant recipients

    International Nuclear Information System (INIS)

    Mentzel, Hans-J.; Boettcher, Joachim; Malich, Ansgar; Pfeil, Alexander; Kaiser, Werner A.; John, Ulrike; Misselwitz, Joachim; Vollandt, Ruediger

    2005-01-01

    Loss of bone mass and increased fracture risk are known complications after renal transplantation in adults. Risk factors include donor source, dialysis status prior to transplantation, aetiology of renal disease, transplant rejection and drug therapy, particularly steroids. In this preliminary study of quantification of bone loss in children after renal transplantation, we evaluated the applicability of digital X-ray radiogrammetry (DXR) of hand radiographs to estimate cortical bone mineral density (DXR-BMD). A total of 23 renal transplant recipients (9 girls, 14 boys; age 6.5-20 years, median 16.3 years) underwent DXR measurements for calculation of DXR-BMD and metacarpal index (DXR-MCI) using radiographs of the non-dominant left hand. The duration between transplantation and the DXR evaluation, the duration of dialysis and medication were considered. The results were compared to a local age-matched and gender-matched reference data base. Our study revealed a significant decrease in bone mineral density compared to an age-matched and sex-matched normal population (P<0.05). In three patients the DXR-BMD was reduced more than -2.5 SD. In 12 patients the DXR-BMD was between -1 and -2.5 SD, and in 7 patients the DXR-BMD was in the normal range. In one patient, evaluation was not possible. Fractures were documented in three patients following transplantation. Reduced DXR-BMD was not significantly associated with immunosuppressive therapy or the duration of dialysis, and there was no significant correlation between DXR-BMD and the time between transplantation and DXR evaluation. (orig.)

  18. Evaluation of bone-mineral density by digital X-ray radiogrammetry (DXR) in pediatric renal transplant recipients

    Energy Technology Data Exchange (ETDEWEB)

    Mentzel, Hans-J.; Boettcher, Joachim; Malich, Ansgar; Pfeil, Alexander; Kaiser, Werner A. [Friedrich-Schiller-University Jena, Department of Pediatric Radiology, Jena (Germany); John, Ulrike; Misselwitz, Joachim [Friedrich-Schiller-University Jena, Department of Pediatric Nephrology, Jena (Germany); Vollandt, Ruediger [Friedrich-Schiller-University Jena, Institute of Medical Statistics, Computer Sciences and Documentation, Jena (Germany)

    2005-05-01

    Loss of bone mass and increased fracture risk are known complications after renal transplantation in adults. Risk factors include donor source, dialysis status prior to transplantation, aetiology of renal disease, transplant rejection and drug therapy, particularly steroids. In this preliminary study of quantification of bone loss in children after renal transplantation, we evaluated the applicability of digital X-ray radiogrammetry (DXR) of hand radiographs to estimate cortical bone mineral density (DXR-BMD). A total of 23 renal transplant recipients (9 girls, 14 boys; age 6.5-20 years, median 16.3 years) underwent DXR measurements for calculation of DXR-BMD and metacarpal index (DXR-MCI) using radiographs of the non-dominant left hand. The duration between transplantation and the DXR evaluation, the duration of dialysis and medication were considered. The results were compared to a local age-matched and gender-matched reference data base. Our study revealed a significant decrease in bone mineral density compared to an age-matched and sex-matched normal population (P<0.05). In three patients the DXR-BMD was reduced more than -2.5 SD. In 12 patients the DXR-BMD was between -1 and -2.5 SD, and in 7 patients the DXR-BMD was in the normal range. In one patient, evaluation was not possible. Fractures were documented in three patients following transplantation. Reduced DXR-BMD was not significantly associated with immunosuppressive therapy or the duration of dialysis, and there was no significant correlation between DXR-BMD and the time between transplantation and DXR evaluation. (orig.)

  19. Evaluation of medical exposure and exposure by the public in a typical scenario of examinations using mobile X-ray equipment through the Monte Carlo simulation

    International Nuclear Information System (INIS)

    Santos, Felipe A.; Galeano, Diego C.; Santos, William S.; Carvalho Júnior, Albérico B.

    2016-01-01

    In this work irradiation scenarios that simulated chest and abdomen examinations involving mobile X-ray equipment in hospitals were modeled with the purpose of calculating conversion coefficient for effective dose (CC E ), normalized to entrance surface dose (ESD), applied to patients and public individuals. These coefficients can easily be used in this practice. Patients and public individuals were represented by a pair of anthropomorphic phantoms inserted in the MCNPX 2.7.0 radiation transport code. One of the phantoms (patient) was irradiated with the direct beam simulating examinations of the chest and abdomen, each with two fields of irradiation, ideal (IF) and extrapolated (EF). Using the software SPECGEN X-ray spectra from 60 to 100 kVp at 10 kVp intervals were generated and used in this work. The other phantom (public individual) was positioned 50–200 cm from the patient. In relation to the CC E calculated in the patient, the average increase obtained between the irradiation fields was 62.4% for the chest examinations, and for the same conditions the CC E was calculated for abdomen examinations and found to be 8.0%. Increasing the distance between public individual and patient, reductions of up to 81.7% in the CC E in abdomen examinations and 83.4% in chest examinations were observed. Through the assessment of CC E of these scenarios, it is possible to measure the damages relating to this practice for both patients and public individuals. - Highlights: • A computational scenario involving mobile X-ray equipment in hospitals were modeled. • Evaluation of medical exposure and exposure by the public was made by CC E (E/ESD). • A pair of the anthropomorphic simulators was inserted into the input file MCNPX. • Analyze the influence in CC E for the different types of fields used in examinations. • Monitoring the reduction of CC E 's with increasing distance between the beds.

  20. Dose values at the ovaries for sagittal irradiation equipment in X-ray pictures using a standard phantom

    International Nuclear Information System (INIS)

    Kragh, P.

    1977-07-01

    The dose values at the ovaries are calculated systematically with a phantom corresponding in its shape and composition to the human anatomy. In order to limit computer time for the photon transport calculations according to the Monte-Carlo-method the simplified method of calculation is used which was first stated by Rosenstein. The dose at the ovaries is listed in tables for the respective X-ray exposure in a.p. or p.a. direction at the standard film sizes. In addition, the exposure area product of the useful radiation and the distances of a reference point to the central beam and to the edge of the radiation field must be known. (orig.) [de

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

    Science.gov (United States)

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

    2013-06-01

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

  2. X-Ray

    Science.gov (United States)

    ... enema. What you can expect During the X-ray X-rays are performed at doctors' offices, dentists' offices, ... as those using a contrast medium. Your child's X-ray Restraints or other techniques may be used to ...

  3. Abdominal x-ray

    Science.gov (United States)

    Abdominal film; X-ray - abdomen; Flat plate; KUB x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  4. Chest X-Ray

    Medline Plus

    Full Text Available ... talk with you about chest radiography also known as chest x-rays. Chest x-rays are the ... treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray ...

  5. Fabrication and characterization of a 32 x 32 array digital Si-PIN X-ray detector for a single photon counting image sensor

    International Nuclear Information System (INIS)

    Seo, Jungho; Kim, Jinyoung; Lim, Hyunwoo; Park, Jingoo; Lee, Songjun; Kim, Bonghoe; Jeon, Sungchae; Huh, Young

    2010-01-01

    A Si-PIN X-ray detector for digital x-ray imaging with single photon counting capability has been fabricated and characterized. It consists of an array of 32 x 32 pixels with an area of 80 x 80 μm 2 . An extrinsic gettering process was performed to reduce the leakage current by removing the impurities and defects from the X-ray detector's Si substrate. Multiple guard-rings (MGRs) and metal filed plates (MFPs) techniques were adopted to reduce the leakage current and to improve the breakdown performance. The simulation verified that the breakdown voltage was improved with the MGRs and that the leakage current was significantly reduced with the MFPs. The electrical properties, such as the leakage current and the breakdown voltage, of the Si-PIN X-ray detector were characterized. The extrinsic gettering process played a significant role in reducing the leakage current, and a leakage current lower than 60 pA could be achieved at 100 V dc .

  6. Improvement in the clinical practicability of roentgen stereophotogrammetric analysis (RSA): free from the use of the dual X-ray equipment.

    Science.gov (United States)

    Shih, Kao-Shang; Lee, Chian-Her; Syu, Ci-Bin; Lai, Jiing-Yih; Chen, Kuo-Jen; Lin, Shang-Chih

    2012-10-01

    After total knee replacement, the monitoring of the prosthetic performance is often done by roentgenographic examination. However, the two-dimensional (2D) roentgen images only provide information about the projection onto the anteroposterior (AP) and mediolateral (ML) planes. Historically, the model-based roentgen stereophotogrammetric analysis (RSA) technique has been developed to predict the spatial relationship between prostheses by iteratively comparing the projective data for the prosthetic models and the roentgen images. During examination, the prosthetic poses should be stationary. This should be ensured, either by the use of dual synchronized X-ray equipment or by the use of a specific posture. In practice, these methods are uncommon or technically inconvenient during follow-up examination. This study aims to develop a rotation platform to improve the clinical applicability of the model-based RSA technique. The rotation platform allows the patient to assume a weight-bearing posture, while being steadily rotated so that both AP and ML knee images can be obtained. This study uses X-ray equipment with a single source and flat panel detectors (FPDs). Four tests are conducted to evaluate the quality of the FPD images, steadiness of the rotation platform, and accuracy of the RSA results. The results show that the distortion-induced error of the FPD image is quite minor, and the prosthetic size can be cautiously calibrated by means of the scale ball(s). The rotation platform should be placed closer to the FPD and orthogonal to the projection axis of the X-ray source. Image overlap of the prostheses can be avoided by adjusting both X-ray source and knee posture. The device-induced problems associated with the rotation platform include the steadiness of the platform operation and the balance of the rotated subject. Sawbone tests demonstrate that the outline error, due to the platform, is of the order of the image resolution (= 0.145 mm). In conclusion, the rotation

  7. X-ray astronomy

    International Nuclear Information System (INIS)

    Giacconi, R.; Gursky, H.

    1974-01-01

    This text contains ten chapters and three appendices. Following an introduction, chapters two through five deal with observational techniques, mechanisms for the production of x rays in a cosmic setting, the x-ray sky and solar x-ray emission. Chapters six through ten include compact x-ray sources, supernova remnants, the interstellar medium, extragalactic x-ray sources and the cosmic x-ray background. Interactions of x rays with matter, units and conversion factors and a catalog of x-ray sources comprise the three appendices. (U.S.)

  8. Fine Output Voltage Control Method considering Time-Delay of Digital Inverter System for X-ray Computed Tomography

    Science.gov (United States)

    Shibata, Junji; Kaneko, Kazuhide; Ohishi, Kiyoshi; Ando, Itaru; Ogawa, Mina; Takano, Hiroshi

    This paper proposes a new output voltage control for an inverter system, which has time-delay and nonlinear load. In the next generation X-ray computed tomography of a medical device (X-ray CT) that uses the contactless power transfer method, the feedback signal often contains time-delay due to AD/DA conversion and error detection/correction time. When the PID controller of the inverter system is received the adverse effects of the time-delay, the controller often has an overshoot and a oscillated response. In order to overcome this problem, this paper proposes a compensation method based on the Smith predictor for an inverter system having a time-delay and the nonlinear loads which are the diode bridge rectifier and X-ray tube. The proposed compensation method consists of the hybrid Smith predictor system based on an equivalent analog circuit and DSP. The experimental results confirm the validity of the proposed system.

  9. X-raying with low dose irradiation

    International Nuclear Information System (INIS)

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

    2001-01-01

    with higher frequency of a pulsation the share of unproductive radiation is higher. At x-raying controlled by the grid pulses are generated by the x-ray tube with the grid control. The grid, located between the cathode and the anode, passes the electron cloud without the expenses of time for dispersal and attenuation. It gives sharply outlined, rectangular x-ray pulses with homogeneous quality of radiation. Function GC F -x-raying controlled by the grid - enables to receive precisely outlined contours of moving objects: a heart, a gullet, - and also to carry out examination of the children without information loss during simultaneous dose decrease. Besides the image remains precise even during the movement of the electron-optical converter. Owing to radiation parameters adjustment during the examination the effect of the lighted image is eliminated. X-raying devices Easy Diagnose and Diagnose-76 'Philips' are equipped with the system of digital x-ray image processing besides they are completed with the x-ray tube with Grid Controlled Fluoroscopy that allows to carry out pulse x-raying with number of pulses 2, 3, 6 and 12 per a second. So, with 12 pulses per second the irradiation dose in comparison with continuous radiation decreases on 40%. The examinations of a chest, gullet, stomach and thick gut were carried out at the frequency of 12 and 6 pulses per second. In the hospital of the Ministry of Internal Affairs where device Easy Diagnose is established, at examinations of a gastro enteric path (stomach x-raying, irrigoscopy) usually pulse x-raying is used with frequency 12 pulses per second. It allows significantly reduce the beam load on a patient. The calculation of beam loads on a patient was carried out on the basis of exposition dose level at the beam input in the body of a patient (entrance dose). The way is applied for especially exact calculations, as definitions of effective doses on separate organs and all body are difficult. The irradiation dose is in

  10. 50 μm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis

    International Nuclear Information System (INIS)

    Zhao, C; Kanicki, J; Konstantinidis, A C; Zheng, Y; Speller, R D; Anaxagoras, T

    2015-01-01

    Wafer-scale CMOS active pixel sensors (APSs) have been developed recently for x-ray imaging applications. The small pixel pitch and low noise are very promising properties for medical imaging applications such as digital breast tomosynthesis (DBT). In this work, we evaluated experimentally and through modeling the imaging properties of a 50 μm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). A modified cascaded system model was developed for CMOS APS x-ray detectors by taking into account the device nonlinear signal and noise properties. The imaging properties such as modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) were extracted from both measurements and the nonlinear cascaded system analysis. The results show that the DynAMITe x-ray detector achieves a high spatial resolution of 10 mm −1 and a DQE of around 0.5 at spatial frequencies  <1 mm −1 . In addition, the modeling results were used to calculate the image signal-to-noise ratio (SNR i ) of microcalcifications at various mean glandular dose (MGD). For an average breast (5 cm thickness, 50% glandular fraction), 165 μm microcalcifications can be distinguished at a MGD of 27% lower than the clinical value (∼1.3 mGy). To detect 100 μm microcalcifications, further optimizations of the CMOS APS x-ray detector, image aquisition geometry and image reconstruction techniques should be considered. (paper)

  11. Development of a dosimetric system for dental X-ray equipment quality control; Desenvolvimento de um sistema dosimetrico para controle de qualidade de equipamentos de raios-X odontologicos

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Francisco Almeida de

    2002-08-01

    An electronic instrument with digital readout was designed and constructed to provide fast, simple and non-invasive measurements of X-ray dental equipment parameters. This instrument is capable of evaluating the entrance dose, exposure time, tube voltage (kVp) and beam filtration. It consists of a set of five photodiodes connected each one in the photocurrent mode to the input of a designed integrating electrometer. Three of the detectors are fixed under aluminium filters with different thicknesses, one is fixed under a 0.3 mm copper filter and the other has no filtration. The readings of the three detectors under aluminium filters and of the bare detector permit the determination of the half-value layer, which is used to calculate the beam filtration. The ratio between the readings of the detector below the copper filter and the one without filtration is used to determine the tube voltage. The signal produced by the detector without filter is used to evaluate the patient entrance dose, and to active an electronic timer for measuring the real exposure time. The tests and calibration of the instrument in different voltages in the 59 - 70kVp range, showed that its response is both stable and reproducible to within 1%. The instrument response was compared to the one from a commercial non-invasive X-ray test equipment (Gammex RMI Multifunction kVp meter). The results showed that the response of the developed instrument is in good agreement with the RMI meter which is the standard equipment for such measurements. These results indicate that the dosimetric system is suitable for use in Dental Quality Assurance Programs. (author)

  12. 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)

    Passos, Robson Silva

    1999-05-01

    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/m 2 . 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

  13. Local liquid velocity measurement in trickle bed reactors (TBRs) using the x-ray digital industrial radiography (DIR) technique

    International Nuclear Information System (INIS)

    Salleh, Khairul Anuar Mohd; Lee, Hyoung Koo; Al-Dahhan, Muthanna H

    2014-01-01

    This work describes the development of a new technique to measure local liquid velocity (V LL ) for multiphase flows in trickle bed reactors (TBRs) (gas–liquid–solid system). In the studied TBR, the liquid phase is represented by water, gas by air and 3 mm expanded polystyrene beads as the solid packing. Three different superficial liquid velocities (V SL ) and a constant superficial gas velocity (V SG ) were used in the packed bed with an internal diameter of 4.25 cm. While the liquid is moving into the packed bed, tracking particles of 106–125 μm diameter (16.45% difference) are injected. The movement of the tracking particles is monitored and digitally recorded by a complementary metal–oxide–semiconductor detector. In this experiment, x-rays were used as the radiation source. Four replications were made with fresh packing. Comparable observations can be found from other published techniques (i.e. magnetic resonance imaging). Results from this study indicate that, at V SL = 0.13 cm s −1 , the measured V LL  can reach up to 51 times that of its V SL , while for V SL = 0.27 cm s −1 , the measured V LL  reached up to 35 times higher than the V SL and for V SL = 0.39 cm s −1 , the V LL  reached up to 39.8 times higher than its V SL . Through statistical analysis, the implementation of such a method is found to be reproducible throughout the experiments. The mean per cent difference in the measured V LL was 10% and 5% for lower implemented V SL   of 0.13 and 0.27 cm s −1 , respectively. At higher V SL  (0.39 cm s −1 ), the particle tracer was greatly distributed and carried away by the high liquid flow rate. The variance or the range of the measured V LL  does not vary for all replications in every V SL , which confirms the reproducibility of the experimental measurements, regardless of the V SL . (paper)

  14. Preliminary evaluation of a prototype stereoscopic a-Si:H-based X-ray imaging system for full-field digital mammography

    International Nuclear Information System (INIS)

    Darambara, D.G.; Speller, R.D.; Horrocks, J.A.; Godber, S.; Wilson, R.; Hanby, A.

    2001-01-01

    In a pre-clinical study, we have been investigating the potential of a-Si:H active matrix, flat panel imagers for X-ray full-field digital mammography through the development of an advanced 3D X-ray imaging system and have measured a number of their important imaging characteristics. To enhance the information embodied into the digital images produced by the a-Si array, stereoscopic images, created by viewing the object under examination from two angles and recombining the images, were obtained. This method provided us with a full 3D X-ray image of the test object as well as left and right perspective 2D images all at the same time. Within this scope, images of fresh, small human breast tissue specimens--normal and diseased--were obtained at ±2 deg., processed and stereoscopically displayed for a pre-clinical evaluation by radiologists. It was demonstrated that the stereoscopic presentation of the images provides important additional information and has potential benefits over the more traditional 2D data

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  16. Fabrication and characterization of pixelated Gd{sub 2}O{sub 2}S:Tb scintillator screens for digital X-ray imaging applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongyul, E-mail: kjongyul@kaist.ac.kr [Korea Advanced Institute of Science and Technology, 335 Gwahangno, Daejeon 305-701 (Korea, Republic of); Kyoung Cha, Bo; Hyung Bae, Jun; Lee, Chae-hun; Kim, Hyungtaek; Chang, Sungho; Cho, Gyuseong [Korea Advanced Institute of Science and Technology, 335 Gwahangno, Daejeon 305-701 (Korea, Republic of); Sim, Cheulmuu; Kim, Taejoo [Korea Atomic Energy Research Institute, 150 Deokjin-dong, Daejeon 305-353 (Korea, Republic of)

    2011-05-15

    X-ray imaging detectors in combination with scintillator screens have been widely used in digital X-ray imaging applications. Gd{sub 2}O{sub 2}S:Tb was used as scintillation material for pixelated scintillator screens based on silicon substrates (wafer) with a micropore array of various dimensions fabricated using the photolithography and deep reactive ion etching (DRIE) process. The relative light output and the modulation transfer function (MTF) of each fabricated scintillator screen were measured by a cooled CCD and compared with those of Lanex screens. The spatial resolution of our scintillator screens was higher but their light outputs were lower than those of Lanex screen probably due to the loss of light at the wall surfaces. Therefore further treatment of the wall surface, such as reflective coating, seems necessary to compensate the light loss.

  17. Improvements of visual X-ray inspection with optimized digital detector technology. Faster and more reliable inspection with High Dynamic Radiology (HDR)

    International Nuclear Information System (INIS)

    Bavendiek, Klaus

    2010-01-01

    Improvements in speed and contrast resolution of Digital Detector Arrays (DDA) and significant higher power of X-Ray tubes in combination with a small focal spot open the door to an improved visual inspection of castings for automotive and aerospace applications. The result is a film-like image quality of castings in a live view. For the new image quality the x-ray parameter have to be optimized in energy and the subject contrast has to be increased to avoid that flaws are covered by the noise in the image. HDR - high dynamic radiology - expands the local contrast in the image and transfers the grey values to the range the human inspector can separate. Due to the movement in the image the inspector gets a glas-like impression of the object and the flaws allowing him to do a decision about the 3D position of a flaw in the object. (orig.)

  18. Chest X-Ray

    Medline Plus

    Full Text Available ... about chest radiography also known as chest x-rays. Chest x-rays are the most commonly performed x-ray exams and use a very small dose of ... of the inside of the chest. A chest x-ray is used to evaluate the lungs, heart and ...

  19. X-ray sky

    International Nuclear Information System (INIS)

    Gruen, M.; Koubsky, P.

    1977-01-01

    The history is described of the discoveries of X-ray sources in the sky. The individual X-ray detectors are described in more detail, i.e., gas counters, scintillation detectors, semiconductor detectors, and the principles of X-ray spectrometry and of radiation collimation aimed at increased resolution are discussed. Currently, over 200 celestial X-ray sources are known. Some were identified as nebulae, in some pulsations were found or the source was identified as a binary star. X-ray bursts of novae were also observed. The X-ray radiation is briefly mentioned of spherical star clusters and of extragalactic X-ray sources. (Oy)

  20. Flash x-ray cinematography

    International Nuclear Information System (INIS)

    Stein, W.E.

    1976-01-01

    Experiments intended to provide an overview of the potential capabilities and limitations of flash x-ray cinematography as a diagnostic technique for a Fast Reactor Safety Test Facility are described. The results provide estimates of the x-ray pulse intensity required to obtain adequate radiographs of an array of fuel pins in a typical reactor configuration. An estimate of the upper limit on the pulse duration imposed by the reactor background radiation was also determined. X-ray cinematography has been demonstrated at a repetition rate limited only by the recording equipment on hand at the time of these measurements. These preliminary results indicate that flash x-ray cinematography of the motion of fuel in a Fast Reactor Test Facility is technically feasible

  1. X-ray radiotherapy

    International Nuclear Information System (INIS)

    Tronc, D.

    1995-01-01

    major medical equipment companies manufacture X-ray therapy systems - General Electric, Mitsubishi, Philips, Siemens and Varian. In this crowded marketplace where the useful lifespan of machines exceeds 10 years, purchase prices are less than $1 million per unit. X-ray therapy remains the most common and cheapest form of accelerator therapy. Ongoing technical developments aim to achieve better matching of dose delivery to tumour volume; multileaf collimators shape the X-ray field to the biomedical target, and portal imaging from behind the patient can control positioning and dose delivery. Combined compact X-ray sources are being developed with both treatment and realtime dosimetry control, incorporating CT scanning into one single device. Integrated diagnosis and therapy is the direction for R&D investment, and this should lead to smaller hospital space requirements, lower operating costs, and elimination of external data handling, resulting in simpler and more cost effective clinical procedures

  2. Experimental characterization of a 10 μW 55 μm-pitch FPN-compensated CMOS digital pixel sensor for X-ray imagers

    Energy Technology Data Exchange (ETDEWEB)

    Figueras, Roger, E-mail: roger.figueras@imb-cnm.csic.es [Institut de Microelectrònica de Barcelona IMB-CNM(CSIC), Bellaterra (Spain); Martínez, Ricardo; Terés, Lluís [Institut de Microelectrònica de Barcelona IMB-CNM(CSIC), Bellaterra (Spain); Serra-Graells, Francisco [Institut de Microelectrònica de Barcelona IMB-CNM(CSIC), Bellaterra (Spain); Department of Microelectronics and Electronic Systems, Universitat Autònoma de Barcelona, Bellaterra (Spain)

    2014-10-11

    This paper presents experimental results obtained from both electrical and radiation tests of a new room-temperature digital pixel sensor (DPS) circuit specifically optimized for digital direct X-ray imaging. The 10 μW 55 μm-pitch CMOS active pixel circuit under test includes self-bias capability, built-in test, selectable e{sup −}/h{sup +} collection, 10-bit charge-integration A/D conversion, individual gain tuning for fixed pattern noise (FPN) cancellation, and digital-only I/O interface, which make it suitable for 2D modular chip assemblies in large and seamless sensing areas. Experimental results for this DPS architecture in 0.18 μm 1P6M CMOS technology are reported, returning good performance in terms of linearity, 2ke{sub rms}{sup −} of ENC, inter-pixel crosstalk below 0.5 LSB, 50 Mbps of I/O speed, and good radiation response for its use in digital X-ray imaging.

  3. Evaluation device of diagnostic X-ray beam

    International Nuclear Information System (INIS)

    Pela, Carlos Alberto; Paula, Eldereis de; Bruco, Jose Luiz; Ghilardi Netto, Thomaz

    1996-01-01

    A device developed to determine the physical parameters useful to the evaluation of both dental and medical X-ray equipment is presented. Nine detectors connected each one to a signal amplifier are used. The amplifiers output has being connected to an analog to digital interface plugged in a PC-AT microcomputer. The X-ray pass through filters before reaching the detectors. The data collected by microcomputer are used to calculate the kVp and other factors as total tube filtration, waveform, half-value layer, exposure rate and exposure time

  4. Comparison of vessel contrast measured with a scanning-beam digital x-ray system and an image intensifier/television system

    International Nuclear Information System (INIS)

    Speidel, Michael A.; Wilfley, Brian P.; Heanue, Joseph A.; Betts, Timothy D.; Van Lysel, Michael S.

    2001-01-01

    Vessel contrast was measured in the fluoroscopic images produced by a scanning-beam digital x-ray (SBDX) system and an image intensifier/television (II/TV) based system. The SBDX system electronically scans a series of pencil x-ray beams across the patient, each of which is directed at a distant small-area detector array. The reduction in detected scatter achieved with this geometry was expected to provide an increase in image contrast. Vessel contrast was evaluated from images of a phantom containing iodinated tubes. The vessels were inserted into an acrylic stack to provide a patient-mimicking scattering medium. Vessel diameter ranged from 0.3 to 3.1 mm. Images were acquired at 100 kVp with the SBDX and II/TV systems and averaged to reduce x-ray noise. The II/TV system was operated in the 6-in. image intensifier mode with an anti-scatter grid. The increase in contrast in the SBDX images, expressed as a ratio of the measured SBDX and II/TV contrasts, ranged from 1.63 to 1.79 for individual vessels. This agreed well with a prediction of the contrast improvement ratio for this experiment, based on measurements of the scatter fraction, object-plane line spread functions, and consideration of the source spectrum and detector absorption properties. The predicted contrast improvement ratio for SBDX relative to II/TV images was 1.62 to 1.77

  5. Simultaneous high speed digital cinematographic and X-ray radiographic imaging of a intense multi-fluid interaction with rapid phase changes

    Energy Technology Data Exchange (ETDEWEB)

    Hansson, Roberta Concilio; Park, Hyun Sun; Dinh, Truc-Nam [Royal Institute of Technology, Division of Nuclear Power Safety, AlbaNova, Stockholm SE-106 91 (Sweden)

    2009-04-15

    As typical for the study of the vapor explosions, the qualitative and quantitative understanding of the phenomena requires visualization of both material and interface dynamics. A new approach to multi-fluid multiphase visualization is presented with the focus on the development of a synchronized high-speed visualization by digital cinematography and X-ray radiography. The developed system, named SHARP (simultaneous high-speed acquisition of X-ray radiography and photography), and its image processing methodology, directed to an image synchronization procedure and a separate quantification of vapor and molten material dynamics, is presented in this paper. Furthermore, we exploit an intrinsic property of the X-ray radiation, namely the differences in linear mass attenuation coefficients over the beam path through a multi-component system, to characterize the evolution of molten material distribution. Analysis of the data obtained by the SHARP system and image processing procedure developed granted new insights into the physics of the vapor explosion phenomena, as well as, quantitative information of the associated dynamic micro-interactions. (author)

  6. Method for measuring the focal spot size of an x-ray tube using a coded aperture mask and a digital detector.

    Science.gov (United States)

    Russo, Paolo; Mettivier, Giovanni

    2011-04-01

    The goal of this study is to evaluate a new method based on a coded aperture mask combined with a digital x-ray imaging detector for measurements of the focal spot sizes of diagnostic x-ray tubes. Common techniques for focal spot size measurements employ a pinhole camera, a slit camera, or a star resolution pattern. The coded aperture mask is a radiation collimator consisting of a large number of apertures disposed on a predetermined grid in an array, through which the radiation source is imaged onto a digital x-ray detector. The method of the coded mask camera allows one to obtain a one-shot accurate and direct measurement of the two dimensions of the focal spot (like that for a pinhole camera) but at a low tube loading (like that for a slit camera). A large number of small apertures in the coded mask operate as a "multipinhole" with greater efficiency than a single pinhole, but keeping the resolution of a single pinhole. X-ray images result from the multiplexed output on the detector image plane of such a multiple aperture array, and the image of the source is digitally reconstructed with a deconvolution algorithm. Images of the focal spot of a laboratory x-ray tube (W anode: 35-80 kVp; focal spot size of 0.04 mm) were acquired at different geometrical magnifications with two different types of digital detector (a photon counting hybrid silicon pixel detector with 0.055 mm pitch and a flat panel CMOS digital detector with 0.05 mm pitch) using a high resolution coded mask (type no-two-holes-touching modified uniformly redundant array) with 480 0.07 mm apertures, designed for imaging at energies below 35 keV. Measurements with a slit camera were performed for comparison. A test with a pinhole camera and with the coded mask on a computed radiography mammography unit with 0.3 mm focal spot was also carried out. The full width at half maximum focal spot sizes were obtained from the line profiles of the decoded images, showing a focal spot of 0.120 mm x 0.105 mm at 35

  7. The critical examination of X-ray generating equipment in diagnostic radiology. Guidance on the interpretation of the Ionising Radiation Regulations 1985, Regulation 32(2)a

    International Nuclear Information System (INIS)

    1998-01-01

    Regulation 32(2)a requires an examination, where appropriate, of X-ray equipment and its operating environment, following its installation, repair or modification. In this context 'appropriate' means - 'if there are possible radiation protection implications'. The examination should be carried out before the equipment is brought into use. The intent of the Regulation is to ensure that the installation process does not compromise the radiation safety of the equipment as provided for by its original design and manufacture, and that any persons who might be exposed are adequately protected. However, the scope of the Regulation does not directly cover features controlling the optimisation of dose for a medical exposure. An examination of the equipment relating to the radiation protection consequences of the way it was installed is required. This is termed 'critical', emphasising the need to review the installation to a greater degree than the simple fulfilment of a preconceived test procedure. The involvement of a radiation protection adviser is required as an expert in radiation safety. This document provides guidance on when it is necessary to carry out a critical examination, and on its content. The Ionising Radiations Regulations 1985 firmly place the responsibility for ensuring that a critical examination is carried out, on the installer of the equipment. However, knowledge of various aspects of the critical examination is also relevant to employers who manage health related facilities, as well as their RPAs, and physicists who carry out equipment tests. Aside from the actual examination itself, there are issues pertaining to purchase contracts, and a knowledge of the satisfactory completion of a critical examination will be relevant to an employer in fulfilling his duties under Regulations 6 and 33. (author)

  8. The critical examination of X-ray generating equipment in diagnostic radiology. Guidance on the interpretation of the Ionising Radiation Regulations 1985, Regulation 32(2)a

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    Regulation 32(2)a requires an examination, where appropriate, of X-ray equipment and its operating environment, following its installation, repair or modification. In this context 'appropriate' means - 'if there are possible radiation protection implications'. The examination should be carried out before the equipment is brought into use. The intent of the Regulation is to ensure that the installation process does not compromise the radiation safety of the equipment as provided for by its original design and manufacture, and that any persons who might be exposed are adequately protected. However, the scope of the Regulation does not directly cover features controlling the optimisation of dose for a medical exposure. An examination of the equipment relating to the radiation protection consequences of the way it was installed is required. This is termed 'critical', emphasising the need to review the installation to a greater degree than the simple fulfilment of a preconceived test procedure. The involvement of a radiation protection adviser is required as an expert in radiation safety. This document provides guidance on when it is necessary to carry out a critical examination, and on its content. The Ionising Radiations Regulations 1985 firmly place the responsibility for ensuring that a critical examination is carried out, on the installer of the equipment. However, knowledge of various aspects of the critical examination is also relevant to employers who manage health related facilities, as well as their RPAs, and physicists who carry out equipment tests. Aside from the actual examination itself, there are issues pertaining to purchase contracts, and a knowledge of the satisfactory completion of a critical examination will be relevant to an employer in fulfilling his duties under Regulations 6 and 33. (author)

  9. Method for dose-reduced 3D catheter tracking on a scanning-beam digital x-ray system using dynamic electronic collimation

    Science.gov (United States)

    Dunkerley, David A. P.; Funk, Tobias; Speidel, Michael A.

    2016-03-01

    Scanning-beam digital x-ray (SBDX) is an inverse geometry x-ray fluoroscopy system capable of tomosynthesis-based 3D catheter tracking. This work proposes a method of dose-reduced 3D tracking using dynamic electronic collimation (DEC) of the SBDX scanning x-ray tube. Positions in the 2D focal spot array are selectively activated to create a regionof- interest (ROI) x-ray field around the tracked catheter. The ROI position is updated for each frame based on a motion vector calculated from the two most recent 3D tracking results. The technique was evaluated with SBDX data acquired as a catheter tip inside a chest phantom was pulled along a 3D trajectory. DEC scans were retrospectively generated from the detector images stored for each focal spot position. DEC imaging of a catheter tip in a volume measuring 11.4 cm across at isocenter required 340 active focal spots per frame, versus 4473 spots in full-FOV mode. The dose-area-product (DAP) and peak skin dose (PSD) for DEC versus full field-of-view (FOV) scanning were calculated using an SBDX Monte Carlo simulation code. DAP was reduced to 7.4% to 8.4% of the full-FOV value, consistent with the relative number of active focal spots (7.6%). For image sequences with a moving catheter, PSD was 33.6% to 34.8% of the full-FOV value. The root-mean-squared-deviation between DEC-based 3D tracking coordinates and full-FOV 3D tracking coordinates was less than 0.1 mm. The 3D distance between the tracked tip and the sheath centerline averaged 0.75 mm. Dynamic electronic collimation can reduce dose with minimal change in tracking performance.

  10. Radiation protection in dentistry. Recommended safety procedures for the use of dental x-ray equipment. Safety code 30

    International Nuclear Information System (INIS)

    1994-01-01

    The Radiation Protection Bureau has prepared a series of documents on safety codes to set out requirements for the safe use of radiation-emitting equipment. This Safety Code has been prepared to provide specific guidance to the dentist, dental hygienist, dental assistant and other support personnel concerned with safety procedures and equipment performance. Dental radiography is one of the most valuable tools used in modern dental health care. It makes possible the diagnosis of physical conditions that would otherwise be difficult to identify. The use of dental radiological procedures must be carefully managed, because x-radiation has the potential for damaging healthy cells and tissues. Although no known occurrence of cancer or genetic damage has been observed from radiation doses delivered in modern dentistry, and until more evidence is available, one should practice radiation hygiene with the same care as would be dictated if a hazard were known to exist. The aim of radiation protection in dentistry is to obtain the desired clinical information with minimal radiation exposure to patients, dental personnel and the public. 15 tabs

  11. Radiation protection in dentistry. Recommended safety procedures for the use of dental x-ray equipment. Safety code 30

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The Radiation Protection Bureau has prepared a series of documents on safety codes to set out requirements for the safe use of radiation-emitting equipment. This Safety Code has been prepared to provide specific guidance to the dentist, dental hygienist, dental assistant and other support personnel concerned with safety procedures and equipment performance. Dental radiography is one of the most valuable tools used in modern dental health care. It makes possible the diagnosis of physical conditions that would otherwise be difficult to identify. The use of dental radiological procedures must be carefully managed, because x-radiation has the potential for damaging healthy cells and tissues. Although no known occurrence of cancer or genetic damage has been observed from radiation doses delivered in modern dentistry, and until more evidence is available, one should practice radiation hygiene with the same care as would be dictated if a hazard were known to exist. The aim of radiation protection in dentistry is to obtain the desired clinical information with minimal radiation exposure to patients, dental personnel and the public. 15 tabs.

  12. Radiation safety in X-ray facilities

    International Nuclear Information System (INIS)

    2001-09-01

    The guide specifies the radiation safety requirements for structural shielding and other safety arrangements used in X-ray facilities in medical and veterinary X-ray activities and in industry, research and education. The guide is also applicable to premises in which X-ray equipment intended for radiation therapy and operating at a voltage of less than 25 kV is used. The guide applies to new X-ray facilities in which X-ray equipment that has been used elsewhere is transferred. The radiation safety requirements for radiation therapy X-ray devices operating at a voltage exceeding 25 kV, and for the premices in which such devices are used, are set out in Guide ST 2.2

  13. Radiation safety in X-ray facilities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-09-01

    The guide specifies the radiation safety requirements for structural shielding and other safety arrangements used in X-ray facilities in medical and veterinary X-ray activities and in industry, research and education. The guide is also applicable to premises in which X-ray equipment intended for radiation therapy and operating at a voltage of less than 25 kV is used. The guide applies to new X-ray facilities in which X-ray equipment that has been used elsewhere is transferred. The radiation safety requirements for radiation therapy X-ray devices operating at a voltage exceeding 25 kV, and for the premices in which such devices are used, are set out in Guide ST 2.2.

  14. Chest X-Ray

    Medline Plus

    Full Text Available ... some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to your health. While a chest x-ray use a ... posted: How to Obtain and Share ...

  15. Chest X-Ray

    Medline Plus

    Full Text Available ... X-ray Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey Rubin, a radiologist ... about chest x-rays, visit Radiology Info dot org. Thank you for your time! Spotlight Recently posted: ...

  16. X-ray apparatus

    International Nuclear Information System (INIS)

    Sell, L.J.

    1981-01-01

    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

  17. X-ray - skeleton

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003381.htm X-ray - skeleton To use the sharing features on this ... Degenerative bone conditions Osteomyelitis Risks There is low radiation exposure. X-rays machines are set to provide the smallest ...

  18. X-ray spectrometry

    International Nuclear Information System (INIS)

    Markowicz, A.A.; Van Grieken, R.E.

    1986-01-01

    In the period under review, i.e, through 1984 and 1985, some 600 articles on XRS (X-ray spectrometry) were published; most of these have been scanned and the most fundamental ones are discussed. All references will refer to English-language articles, unless states otherwise. Also general books have appeared on quantitative EPXMA (electron-probe X-ray microanalysis) and analytical electron microscopy (AEM) as well as an extensive review on the application of XRS to trace analysis of environmental samples. In the period under review no radically new developments have been seen in XRS. However, significant improvements have been made. Gain in intensities has been achieved by more efficient excitation, higher reflectivity of dispersing media, and better geometry. Better understanding of the physical process of photon- and electron-specimen interactions led to complex but more accurate equations for correction of various interelement effects. Extensive use of micro- and minicomputers now enables fully automatic operation, including qualitative analysis. However, sample preparation and presentation still put a limit to further progress. Although some authors find XRS in the phase of stabilization or even stagnation, further gradual developments are expected, particularly toward more dedicated equipment, advanced automation, and image analysis systems. Ways are outlined in which XRS has been improved in the 2 last years by excitation, detection, instrumental, methodological, and theoretical advances. 340 references

  19. Amorphous In-Ga-Zn-O thin-film transistor active pixel sensor x-ray imager for digital breast tomosynthesis.

    Science.gov (United States)

    Zhao, Chumin; Kanicki, Jerzy

    2014-09-01

    The breast cancer detection rate for digital breast tomosynthesis (DBT) is limited by the x-ray image quality. The limiting Nyquist frequency for current DBT systems is around 5 lp/mm, while the fine image details contained in the high spatial frequency region (>5 lp/mm) are lost. Also today the tomosynthesis patient dose is high (0.67-3.52 mGy). To address current issues, in this paper, for the first time, a high-resolution low-dose organic photodetector/amorphous In-Ga-Zn-O thin-film transistor (a-IGZO TFT) active pixel sensor (APS) x-ray imager is proposed for next generation DBT systems. The indirect x-ray detector is based on a combination of a novel low-cost organic photodiode (OPD) and a cesium iodide-based (CsI:Tl) scintillator. The proposed APS x-ray imager overcomes the difficulty of weak signal detection, when small pixel size and low exposure conditions are used, by an on-pixel signal amplification with a significant charge gain. The electrical performance of a-IGZO TFT APS pixel circuit is investigated by SPICE simulation using modified Rensselaer Polytechnic Institute amorphous silicon (a-Si:H) TFT model. Finally, the noise, detective quantum efficiency (DQE), and resolvability of the complete system are modeled using the cascaded system formalism. The result demonstrates that a large charge gain of 31-122 is achieved for the proposed high-mobility (5-20 cm2/V s) amorphous metal-oxide TFT APS. The charge gain is sufficient to eliminate the TFT thermal noise, flicker noise as well as the external readout circuit noise. Moreover, the low TFT (sensor imager under 1 mR, indicating good image quality under low dose. A threefold reduction of current tomosynthesis dose is expected if proposed technology is combined with an advanced DBT image reconstruction method. The proposed a-IGZO APS x-ray imager with a pixel pitch6.67 lp/mm) and a low dose (<0.4 mGy) in next generation DBT systems.

  20. X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Vries, J.L. de.

    1976-01-01

    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

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us ... the equipment look like? How does the procedure work? How is the procedure ... diagnose and treat medical conditions. Imaging with x-rays involves exposing a part ...

  2. Chest X-Ray

    Medline Plus

    Full Text Available ... I’d like to talk with you about chest radiography also known as chest x-rays. Chest x-rays are the most ... far outweighs any risk. For more information about chest x-rays, visit Radiology Info dot org. Thank you for your time! ...

  3. 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 ...

  4. Development of an X-ray detector using photodiodes

    International Nuclear Information System (INIS)

    Gonzalez G, J.; Azorin V, J. C.; Sosa A, M. A.; Ceron, P.

    2016-10-01

    Currently the radiation detectors for medical applications are very high value in the market and are difficult to access as training material. In the Sciences and Engineering Division of the Guanajuato University (Mexico) investigations are carried out related to ionizing radiations, especially with X-rays. To overcome the lack of materials has had to resort to borrowing equipment from other institutions, so its use and availability are intermittent. For these reasons is proposed to design and implement an X-ray detector for the use of the work group and the University. This work aims to build an X-ray semiconductor detector using inexpensive and affordable materials, is also proposed the use of a photodiode sensor and an Arduino analog-digital card and a LCD display showing the data. (Author)

  5. Multichannel X-ray detectors

    Energy Technology Data Exchange (ETDEWEB)

    Khabakhpashev, A

    1980-10-01

    A typical design is discussed of multiwire proportional counters and their characteristic feature is explained, ie., the possibility of showing one or two coordinates of the X-ray quantum absorption site. The advantages of such instruments are listed, such as increased sensitivity of determination, the possibility of recording radiations of a different intensity, the possibility of on-line data processing and of the digital display of results. The fields of application include X-ray structural analysis in solid state physics, crystallography, molecular biology, astronomy, materials testing, and medicine.

  6. The present state and future development of X-ray imaging technology

    International Nuclear Information System (INIS)

    Gou Liang; Wang Xuben; Cao Hui

    2002-01-01

    Medical imaging has long been the hot topic of clinical medical sciences, the X-ray imaging equipment is a popular device of current medical imaging, and the digital imaging technology has become a challenge to the conventional plane imaging. The author first discusses that the key of X-ray-based imaging is the generator and detector of X-ray and the improvement of imaging software, and then points out that the future development of medical imaging will aim at the capability of reducing radiation and handling more efficient and accurate data capacity

  7. Methodology For Determination Of Space Control For 3D Reconstruction In Statscan Digital X-Ray Radiology Using Static Frame Model

    Directory of Open Access Journals (Sweden)

    Jacinta S. Kimuyu

    2015-08-01

    Full Text Available The methodology was designed to employ two positioning techniques in order to determine the three-dimensional control space of target points on static metal frame model to be used as space control data in 3D reconstructions in Statscan digital X-Ray imaging. These techniques were digital close-range photogrammetry and precise theodolite positioning method. The space coordinates for the target points were determined 3D using both techniques. Point positioning accuracy 0.5mm in root mean square error of X Y and Z space coordinates was achieved. The outcome of the comparison of the results obtained from both methods were of satisfactory accuracy hence further use of the control space data in Stastcan imaging and 3D reconstruction.

  8. Benefits of Digital Equipment Generic Qualification Activities

    International Nuclear Information System (INIS)

    Thomas, James E.; Steiman, Samuel C.

    2002-01-01

    As a result of nuclear power plant instrumentation and control obsolescence issues, there have been numerous activities during recent years relating to the qualification of digital equipment. Some of these activities have been 'generic' in nature in that the qualification was not limited to plant specific applications, but was intended to cover a broad base of potential applications of the digital equipment. These generic qualifications have been funded by equipment manufacturers and by utility groups and organizations. The generic activities sponsored by the Electric Power Research Institute (EPRI) have been pilot projects for an overall generic qualification approach. The primary benefit resulting from the generic qualification work to date is that a number of digital platforms and digital devices are now available for use in various nuclear safety-related applications. Many of the tests and evaluations necessary to support plant specific applications have been completed. The amount of data and documentation that each utility must develop on a case by case basis has been significantly reduced. There are also a number of additional benefits resulting from these industry efforts. The challenges and difficulties in qualifying digital equipment for safety-related applications are now more clearly understood. EPRI has published a lessons learned document (EPRI Report 1001452, Generic Qualification of Commercial Grade Digital Devices: Lessons Learned from Initial Pilots, which covers several different qualification areas, including device selection, project planning, vendor surveys and design reviews, and electromagnetic compatibility (EMC) qualification. Application of the experience and lessons learned from the EPRI pilot activities should help reduce the effort and cost required for future qualification work. Most generic qualification activities for commercial equipment have been conducted using the approach of EPRI TR-106439, Guideline on Evaluation and Acceptance

  9. A simple, direct method for x-ray scatter estimation and correction in digital radiography and cone-beam CT

    International Nuclear Information System (INIS)

    Siewerdsen, J.H.; Daly, M.J.; Bakhtiar, B.

    2006-01-01

    X-ray scatter poses a significant limitation to image quality in cone-beam CT (CBCT), resulting in contrast reduction, image artifacts, and lack of CT number accuracy. We report the performance of a simple scatter correction method in which scatter fluence is estimated directly in each projection from pixel values near the edge of the detector behind the collimator leaves. The algorithm operates on the simple assumption that signal in the collimator shadow is attributable to x-ray scatter, and the 2D scatter fluence is estimated by interpolating between pixel values measured along the top and bottom edges of the detector behind the collimator leaves. The resulting scatter fluence estimate is subtracted from each projection to yield an estimate of the primary-only images for CBCT reconstruction. Performance was investigated in phantom experiments on an experimental CBCT benchtop, and the effect on image quality was demonstrated in patient images (head, abdomen, and pelvis sites) obtained on a preclinical system for CBCT-guided radiation therapy. The algorithm provides significant reduction in scatter artifacts without compromise in contrast-to-noise ratio (CNR). For example, in a head phantom, cupping artifact was essentially eliminated, CT number accuracy was restored to within 3%, and CNR (breast-to-water) was improved by up to 50%. Similarly in a body phantom, cupping artifact was reduced by at least a factor of 2 without loss in CNR. Patient images demonstrate significantly increased uniformity, accuracy, and contrast, with an overall improvement in image quality in all sites investigated. Qualitative evaluation illustrates that soft-tissue structures that are otherwise undetectable are clearly delineated in scatter-corrected reconstructions. Since scatter is estimated directly in each projection, the algorithm is robust with respect to system geometry, patient size and heterogeneity, patient motion, etc. Operating without prior information, analytical modeling

  10. Psychophysical evaluation of the image quality of a dynamic flat-panel digital x-ray image detector using the threshold contrast detail detectability (TCDD) technique

    Science.gov (United States)

    Davies, Andrew G.; Cowen, Arnold R.; Bruijns, Tom J. C.

    1999-05-01

    We are currently in an era of active development of the digital X-ray imaging detectors that will serve the radiological communities in the new millennium. The rigorous comparative physical evaluations of such devices are therefore becoming increasingly important from both the technical and clinical perspectives. The authors have been actively involved in the evaluation of a clinical demonstration version of a flat-panel dynamic digital X-ray image detector (or FDXD). Results of objective physical evaluation of this device have been presented elsewhere at this conference. The imaging performance of FDXD under radiographic exposure conditions have been previously reported, and in this paper a psychophysical evaluation of the FDXD detector operating under continuous fluoroscopic conditions is presented. The evaluation technique employed was the threshold contrast detail detectability (TCDD) technique, which enables image quality to be measured on devices operating in the clinical environment. This approach addresses image quality in the context of both the image acquisition and display processes, and uses human observers to measure performance. The Leeds test objects TO[10] and TO[10+] were used to obtain comparative measurements of performance on the FDXD and two digital spot fluorography (DSF) systems, one utilizing a Plumbicon camera and the other a state of the art CCD camera. Measurements were taken at a range of detector entrance exposure rates, namely 6, 12, 25 and 50 (mu) R/s. In order to facilitate comparisons between the systems, all fluoroscopic image processing such as noise reduction algorithms, were disabled during the experiments. At the highest dose rate FDXD significantly outperformed the DSF comparison systems in the TCDD comparisons. At 25 and 12 (mu) R/s all three-systems performed in an equivalent manner and at the lowest exposure rate FDXD was inferior to the two DSF systems. At standard fluoroscopic exposures, FDXD performed in an equivalent

  11. Comparison of X-ray radiation exposure during digital subtraction angiography (DSA) and multislice CT angiography (CTA)

    International Nuclear Information System (INIS)

    Bai, Mei; Liu, Bin; Zheng, Junzheng

    2008-01-01

    Full text: Purpose: To compare radiation risk during digital subtraction angiography (DSA) and CT angiography (CTA). Materials and methods: Eighty patients randomly divided into two groups of 40 patients each, were evaluated for coronary atherosclerotic heart disease with 64-slice spiral CT angiography and DSA respectively. For CTA group we divided patients into two subgroups: regular mode and ECG modulation mode. Matix of thermoluminescent dosimeters (TLDs) were placed on patients' skin surface during each examination to access peak skin dose (PSD). A male ART phantom was equipped with TLDs in six different positions to assess achievable organ dose. Effective dose was calculated by commercially available computer programs. Results: For DSA, PSD was 64mGy. Phantom organ dose for lung, heart, stomach, liver, kidney and brain were 11.07mGy, 5.87mGy, 1.42mGy, 2.11mGy, 6.76mGy and 0.001mGy respectively, and effective dose was 4mSv. For regular mode CTA, PSD was 74.5mGy, and CTD vol was 37.9mGy. Phantom organ dose for lung, heart, stomach, liver, kidney and brain were 58mGy, 64.2mGy, 6.6mGy, 9.9mGy, 2.7mGy, 0.072mGy respectively, and effective dose was 16mSv. For ECG modulation mode, PSD was 50.9mGy, and CTD vol was 26.3mGy. Conclusion: According to measured PSD value, deterministic radiation risk for regular mode CTA was little higher than DSA. However for stochastic radiation risk which can be indicated by organ dose and effective dose, regular mode CTA was much higher than DSA. Comparing with regular mode, ECG modulation mode can effectively reduce both stochastic and deterministic radiation risk. (author)

  12. Clinical evaluation of digital angiographic system equipped with the Safire' flat-panel detector of a direct conversion type

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Yoshiaki; Miura, Yusuke; Goto, Keiichi [Shimadzu Corporation, Medical Systems Division, Research and Development, Kyoto (JP)] [and others

    2003-06-01

    This report presents a report on clinical evaluation of our newly developed flat-panel X-ray detector of a direct conversion type, designed to provide images of a resolution higher than, or at least equal to, that ensured by X-ray photographic films, in clinical digital X-ray cinematography. This new detector was named 'Safire' the acronym of 'Shimadzu advanced flat imaging receptor', emphasizing its high technological level, such as the capability to ensure high quality of images. The clinical evaluation of Shimadzu DIGITEX Premier digital angiography system, equipped with this new flat-panel X-ray detector of a direct conversion type, has been started in March, 2003, at the Kokura Memorial Hospital in Kyushu, Japan. (author)

  13. Analysis of Pre-Columbian objetcs from Cupisnique, one of the oldest culture from Perú, using a portable X-ray fluorescence equipment

    Science.gov (United States)

    Bustamante, A.; Cesareo, R.; Brunetti, A.; Rizzutto, M.; Calza, C.; Pereira de Freitas, R.; Holmsquit, U.; Diestra, D.

    2013-12-01

    Cupisnique (2000-200 BC) is one of the first complex societies that developed in the Jetequepeque valley in the "Formative period." It includes several settlements: Puémape on the coast, Limoncarro in middle valley, Montegrande and Tembladera in the upper valley, and Kuntur Wasi in San Pablo. Currently the valley comprises two provinces, Pacasmayo and Chepen in the La Libertad region, north of Lima. Consideration should be given to cupisniques as premetallurgical culture, and the only used metal was gold, which is present in the native state, on the soil surface or shallow, and attracted attention because of color, brightness, weight, ductility, and inalterability. We analyzed three Cupisnique metal objects belonging to the Larco Museum of Lima designated with No. 4 (pectoral), No. 7 (pendant), and No. 12 (bracelet), using a portable energy-dispersive X-ray fluorescence equipment. Mean value for the pectoral were Au (62 %), Ag (23 %), Cu (15 %); for the pendant, Au (81 %), Ag (16.5 %), Cu (2.5 %); and for the bracelet, Au (69.1 %), Ag (20 %), and Cu (10.9 %).

  14. Estimation of dose challenge in radiological exams policontuses patients in public hospital in Santiago with digital radiology equipment

    International Nuclear Information System (INIS)

    Diaz-Munoz Ihmaidan, Gabriela

    2012-01-01

    lonizing radiation is always present in our natural environment and with the development of new technologies in diagnostic radiology we have elevated the exposure to radiation with an increased dose to both patient and professionals. This is of great importance for secondary stochastic effects that could be generated by exposure to ionizing radiation. There are different x-ray entrance dose studies in patients with radiological examinations in conventional radiology equipment, but not in trauma patients examinated with digital radiology equipment where there is a supposed greater exposure to radiation because of the increase of the number of radiological examinations requested. This study determined the doses received by trauma patients in a direct digital x ray equipment (in a ER in Santiago, Chile) and see if the doses are within the ones recommended by international societies. We used thermoluminescent crystals which were first properly calibrated and located in the center of the radiation beam. The results obtained show that using good practice we can obtain acceptable dose levels, independently of the digital equipment used where it is presumed that could give a higher dose of ionizing radiation exposure than conventional x-ray equipment

  15. Experimental investigations of image quality in X-ray mammography with conventional screen film system (SFS), digital phosphor storage plate in/without magnification technique (CR) and digital CCD-technique (CCD)

    International Nuclear Information System (INIS)

    Schulz-Wendtland, R.; Aichinger, U.; Boehner, C.; Dobritz, M.; Wenkel, E.; Bautz, W.; Saebel, M.

    2001-01-01

    Comparison of image quality in X-ray mammography between conventional film screen film system (SFS), digital phosphor storage plate in and without magnification technique (CR) and digital CCD-technique (CCD). Radiograms of an RMI-mammography phantom were acquired using a conventional screen film system, three digital storage plate systems and two digital systems in CCD-technique. Additionally the radiograms of one digital phosphor storage plate system were post-processed regarding contrast and included in the comparison. The detectability of details was best with the digital mammography in CCD-technique. After confirming these promising results in clinical studies, digital mammography should be able to replace conventional screen film technique. (orig.)

  16. Mobile X-ray radiographic systems

    International Nuclear Information System (INIS)

    Buchmann, F.

    1990-01-01

    Mobile X-ray radiography equipment consists of the X-ray source with the generator and the switching and control devices, mounted on a mobile unit for transport to the patient to be examined. These mobile systems, just as the stationary equipment, have been profiting from the technological progress made in the area of X-ray generation, and the considerable improvements thus achieved have altered not only the value of these systems, but also their applicability which frequently comes near that of stationary equipment. (orig./GDG) [de

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

    International Nuclear Information System (INIS)

    Yonehara, Tasuku; Yamaguchi, Makoto; Tsuji, Kouichi

    2010-01-01

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

  18. X-ray astronomy

    International Nuclear Information System (INIS)

    Culhane, J.L.; Sanford, P.W.

    1981-01-01

    X-ray astronomy has been established as a powerful means of observing matter in its most extreme form. The energy liberated by sources discovered in our Galaxy has confirmed that collapsed stars of great density, and with intense gravitational fields, can be studied by making observations in the X-ray part of the electromagnetic spectrum. The astronomical objects which emit detectable X-rays include our own Sun and extend to quasars at the edge of the Universe. This book describes the history, techniques and results obtained in the first twenty-five years of exploration. Space rockets and satellites are essential for carrying the instruments above the Earth's atmosphere where it becomes possible to view the X-rays from stars and nebulae. The subject is covered in chapters, entitled: the birth of X-ray astronomy; the nature of X-radiation; X-rays from the Sun; solar-flare X-rays; X-rays from beyond the solar system; supernovae and their remnants; X-rays from binary stars; white dwarfs and neutron stars; black holes; X-rays from galaxies and quasars; clusters of galaxies; the observatories of the future. (author)

  19. Standardized method for reproducing the sequential X-rays flap

    International Nuclear Information System (INIS)

    Brenes, Alejandra; Molina, Katherine; Gudino, Sylvia

    2009-01-01

    A method is validated to estandardize in the taking, developing and analysis of bite-wing radiographs taken in sequential way, in order to compare and evaluate detectable changes in the evolution of the interproximal lesions through time. A radiographic positioner called XCP® is modified by means of a rigid acrylic guide, to achieve proper of the X ray equipment core positioning relative to the XCP® ring and the reorientation during the sequential x-rays process. 16 subjects of 4 to 40 years old are studied for a total number of 32 registries. Two x-rays of the same block of teeth of each subject have been taken in sequential way, with a minimal difference of 30 minutes between each one, before the placement of radiographic attachment. The images have been digitized with a Super Cam® scanner and imported to a software. The measurements in X and Y-axis for both x-rays were performed to proceed to compare. The intraclass correlation index (ICI) has shown that the proposed method is statistically related to measurement (mm) obtained in the X and Y-axis for both sequential series of x-rays (p=0.01). The measures of central tendency and dispersion have shown that the usual occurrence is indifferent between the two measurements (Mode 0.000 and S = 0083 and 0.109) and that the probability of occurrence of different values is lower than expected. (author) [es

  20. The Image Quality of a Digital Chest X-Ray Radiography System: Comparison of Quantitative Image Quality Analysis and Radiologists' Visual Scoring

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ji Ho [Dept. of Radiology Oncology, Yongsan Hospital, Pusan National University College of Medicine, Yongsan (Korea, Republic of); Chung, Myung Jin [Dept. of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Park, Darl; Kim, Won Taek; Kim, Yong Ho; Ki, Yong Kan; Kim, DFong Hyun; Lee, Ju Hee; Kim, Dong Won [Dept. of Radiology Oncology, Yongsan Hospital, Pusan National University College of Medicine, Yongsan (Korea, Republic of); Jeon, Ho Sang [Reserach Institue for Convergence of Biomedical Science and Technology, Yongsan Hospital, Pusan National University College of Medicine, Yongsan (Korea, Republic of)

    2011-11-15

    To evaluate the performance of imaging devices, which should be periodically monitored to maintain high quality images to the radiologists. Additionally, this evaluation may prevent patients from radiation over-exposure. The most suitable engineering standard for imaging performance evaluation of digital X-ray thoracic images was determined. IEC 62220-1 standards were used to evaluate the performance of the images. In succession, the visibilities of overall image, pneumothorax, and humerus head in anthropomorphic thoracic phantom images were used to evaluate the image qualities by radiologists. The rank correlation coefficient (p) of visual scoring by radiologists with system spatial resolution is not meaningful (p-value, p = 0.295), but is significant with image noise (p-value, p -0.9267). Finally, the noise equivalent quanta (NEQ) presents a high rank correlation for visual scoring of radiologists (p-value, p = 0.9320). Image quality evaluation of radiologists were mainly affected by imaging noise. Hence, the engineered standard for evaluating image noise is the most important index to effectively monitor the performance of X-ray images. Additionally, the NEQ can be used to evaluate the performance of radiographic systems, because it theoretically corresponds to the synthetic image quality of systems.

  1. X-ray system analysis

    International Nuclear Information System (INIS)

    Shapiro, J.S.

    1985-01-01

    An X-ray system tester for measuring anode voltage, cathode voltage, anode current, filament current and line voltage in an X-ray system has a selector which couples one of these analog signals or one of a plurality of processing control signals entered by an operator from a control panel to a digitizing section selectively in accordance with control signals provided to the selector by a computing section. The digitizing section converts the selected signal into a train of pulses having a frequency proportional to the value of the selected signal. These pulses are counted, the counts being used by the computing section to determine the value of the selected signal. This computed value is stored in a computing memory section of the computing section. The computing section is adapted to store a plurality of the sets of signals produced during a corresponding sequence of operational intervals of the X-ray system and determines a measure of the deviation of any selected one of the stored electrical signals over the sequence of operating intervals. Each signal produced during the sequential operational intervals can be recalled to aid analysis of the operation of the X-ray system. (author)

  2. Functional integration of digital radiologic equipment

    International Nuclear Information System (INIS)

    Agnifili, A.; DiStefano, G.; Salcito, G.; Passariello, R.

    1989-01-01

    This paper reports on a pilot project for the functional integration of digital radiologic equipment. Four different systems (a digital subtraction angiography unit, a DF unit, a computer radiography prototype, and a film digitizer) were connected with a link in an Ethernet LAN.ACR-NEMA standards were used to process the images of the different units in the same way. The central computer manages the long-term optical archive and the film laser printer. Some graphic workstations are connected to the picture archiving and communications system, which allows fast retrieval and processing of the images. Patients; data are acquired through the RIS and stored together with the images

  3. Amorphous In–Ga–Zn–O thin-film transistor active pixel sensor x-ray imager for digital breast tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chumin; Kanicki, Jerzy, E-mail: kanicki@eecs.umich.edu [Solid-State Electronic Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-09-15

    Purpose: The breast cancer detection rate for digital breast tomosynthesis (DBT) is limited by the x-ray image quality. The limiting Nyquist frequency for current DBT systems is around 5 lp/mm, while the fine image details contained in the high spatial frequency region (>5 lp/mm) are lost. Also today the tomosynthesis patient dose is high (0.67–3.52 mGy). To address current issues, in this paper, for the first time, a high-resolution low-dose organic photodetector/amorphous In–Ga–Zn–O thin-film transistor (a-IGZO TFT) active pixel sensor (APS) x-ray imager is proposed for next generation DBT systems. Methods: The indirect x-ray detector is based on a combination of a novel low-cost organic photodiode (OPD) and a cesium iodide-based (CsI:Tl) scintillator. The proposed APS x-ray imager overcomes the difficulty of weak signal detection, when small pixel size and low exposure conditions are used, by an on-pixel signal amplification with a significant charge gain. The electrical performance of a-IGZO TFT APS pixel circuit is investigated by SPICE simulation using modified Rensselaer Polytechnic Institute amorphous silicon (a-Si:H) TFT model. Finally, the noise, detective quantum efficiency (DQE), and resolvability of the complete system are modeled using the cascaded system formalism. Results: The result demonstrates that a large charge gain of 31–122 is achieved for the proposed high-mobility (5–20 cm{sup 2}/V s) amorphous metal-oxide TFT APS. The charge gain is sufficient to eliminate the TFT thermal noise, flicker noise as well as the external readout circuit noise. Moreover, the low TFT (<10{sup −13} A) and OPD (<10{sup −8} A/cm{sup 2}) leakage currents can further reduce the APS noise. Cascaded system analysis shows that the proposed APS imager with a 75 μm pixel pitch can effectively resolve the Nyquist frequency of 6.67 lp/mm, which can be further improved to ∼10 lp/mm if the pixel pitch is reduced to 50 μm. Moreover, the

  4. Amorphous In–Ga–Zn–O thin-film transistor active pixel sensor x-ray imager for digital breast tomosynthesis

    International Nuclear Information System (INIS)

    Zhao, Chumin; Kanicki, Jerzy

    2014-01-01

    Purpose: The breast cancer detection rate for digital breast tomosynthesis (DBT) is limited by the x-ray image quality. The limiting Nyquist frequency for current DBT systems is around 5 lp/mm, while the fine image details contained in the high spatial frequency region (>5 lp/mm) are lost. Also today the tomosynthesis patient dose is high (0.67–3.52 mGy). To address current issues, in this paper, for the first time, a high-resolution low-dose organic photodetector/amorphous In–Ga–Zn–O thin-film transistor (a-IGZO TFT) active pixel sensor (APS) x-ray imager is proposed for next generation DBT systems. Methods: The indirect x-ray detector is based on a combination of a novel low-cost organic photodiode (OPD) and a cesium iodide-based (CsI:Tl) scintillator. The proposed APS x-ray imager overcomes the difficulty of weak signal detection, when small pixel size and low exposure conditions are used, by an on-pixel signal amplification with a significant charge gain. The electrical performance of a-IGZO TFT APS pixel circuit is investigated by SPICE simulation using modified Rensselaer Polytechnic Institute amorphous silicon (a-Si:H) TFT model. Finally, the noise, detective quantum efficiency (DQE), and resolvability of the complete system are modeled using the cascaded system formalism. Results: The result demonstrates that a large charge gain of 31–122 is achieved for the proposed high-mobility (5–20 cm 2 /V s) amorphous metal-oxide TFT APS. The charge gain is sufficient to eliminate the TFT thermal noise, flicker noise as well as the external readout circuit noise. Moreover, the low TFT (<10 −13 A) and OPD (<10 −8 A/cm 2 ) leakage currents can further reduce the APS noise. Cascaded system analysis shows that the proposed APS imager with a 75 μm pixel pitch can effectively resolve the Nyquist frequency of 6.67 lp/mm, which can be further improved to ∼10 lp/mm if the pixel pitch is reduced to 50 μm. Moreover, the detector entrance

  5. Evaluation of different X ray equipment and incubators for pediatric radiographic images implementation;Avaliacao de diferentes equipamentos de raios-X e incubadoras para implementacao de imagens radiograficas pediatricas

    Energy Technology Data Exchange (ETDEWEB)

    Carbi, E.D.O.; Souza, R.T.F.; Pina, D.R. [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina. Dept. de Doencas Tropicais e Diagnostico por Imagem

    2009-07-01

    The children frequent/y are exposed to the ionizing radiation and other emotional and physical risks in the attempts repeated to get radiographic images of quality. This study it has as objective to evaluate X ray beam about quality and intensity at three different equipment with single-phase generator of voltage and the absorption factors to 5 different incubators and 3 different cradles in the neonatal UTI of the Clinics Hospital on the Medicine College in Botucatu. The methodology consisted of carrying through measured of half Layer Value and Radiation output for the different X ray equipment with voltage with in between 45 and 100 kVp, applied at the X ray tube. The measures of the absorption factors had been carried through varying the thicknesses of attenuating material (phantom) for the different voltage value with in between 50 and 100kVp. The results had shown the same energy effective for the different X ray equipment and the same absorption factors for the different incubators and evaluated cradles, taking into account, the same thickness of attenuating material and same voltage. (author)

  6. Personal experience with whole-body, low-dosage, digital X-ray scanning (LODOX-Statscan in trauma

    Directory of Open Access Journals (Sweden)

    Zimmermann Heinz

    2009-09-01

    Full Text Available Abstract Background Lodox-Statscan is a whole-body, skeletal and soft-tissue, low-dose X-ray scanner Anterior-posterior and lateral thoraco-abdominal studies are obtained in 3-5 minutes with only about one-third of the radiation required for conventional radiography. Since its approval by the Food and Drug Administration (FDA in the USA, several trauma centers have incorporated this technology into their Advanced Trauma Life Support protocols. This review provides a brief overview of the system, and describes the authors' own experience with the system. Methods We performed a PubMed search to retrieve all references with 'Lodox' and 'Stat-scan' used as search terms. We furthermore used the google search engine to identify existing alternatives. To the best of our knowledge, this is the only FDA-approved device of its kind currently used in trauma. Results and Conclusion The intention of our review has been to sensitize the readership that such alternative devices exist. The key message is that low dosage full body radiography may be an alternative to conventional resuscitation room radiography which is usually a prelude to CT scanning (ATLS algorithm. The combination of both is radiation intensive and therefore we consider any reduction of radiation a success. But only the future will show whether LS will survive in the face of low-dose radiation CT scanners and magnetic resonance imaging devices that may eventually completely replace conventional radiography.

  7. X-ray holography

    International Nuclear Information System (INIS)

    Faigel, G.; Tegze, M.; Belakhovsky, M.; Marchesini, S.; Bortel, G.

    2003-01-01

    In the last decade holographic methods using hard X-rays were developed. They are able to resolve atomic distances, and can give the 3D arrangement of atoms around a selected element. Therefore, hard X-ray holography has potential applications in chemistry, biology and physics. In this article we give a general description of these methods and discuss the developments in the experimental technique. The capabilities of hard X-ray holography are demonstrated by examples

  8. Los Alamos Scientific Laboratory x-ray survey manual

    International Nuclear Information System (INIS)

    Olsher, R.H.

    1980-02-01

    A manual has been developed by the Health Physics Group to establish procedures for routine testing of industrial and analytical x-ray equipment for compliance with applicable LASL administrative requirements and technical bulletins. Radiation protection survey procedures were developed for the following types of equipment: x-ray diffraction and fluorescence analysis systems, industrial cabinet x-ray systems, industrial noncabinet x-ray systems, and electron microscopes

  9. Providing x-rays

    International Nuclear Information System (INIS)

    Mallozzi, P.J.; Epstein, H.M.

    1985-01-01

    This invention provides an apparatus for providing x-rays to an object that may be in an ordinary environment such as air at approximately atmospheric pressure. The apparatus comprises: means (typically a laser beam) for directing energy onto a target to produce x-rays of a selected spectrum and intensity at the target; a fluid-tight enclosure around the target; means for maintaining the pressure in the first enclosure substantially below atmospheric pressure; a fluid-tight second enclosure adjoining the first enclosure, the common wall portion having an opening large enough to permit x-rays to pass through but small enough to allow the pressure reducing means to evacuate gas from the first enclosure at least as fast as it enters through the opening; the second enclosure filled with a gas that is highly transparent to x-rays; the wall of the second enclosure to which the x-rays travel having a portion that is highly transparent to x-rays (usually a beryllium or plastic foil), so that the object to which the x-rays are to be provided may be located outside the second enclosure and adjacent thereto and thus receive the x-rays substantially unimpeded by air or other intervening matter. The apparatus is particularly suited to obtaining EXAFS (extended x-ray fine structure spectroscopy) data on a material

  10. A Digital Power Quality Monitoring Equipment Designed for Digital Substation

    Science.gov (United States)

    Li, Wei; Wang, Xin; Geng, Jiewen

    2018-01-01

    Taking into account both current status and development trend of digital substation, this paper proposed a design of a new multi-channelled digital power quality monitoring equipment with high compatibility. The overall functional structure, hardware architecture, software architecture, interface architecture and some key techniques such as IEC 61850 modelling of transient event and harmonic measurement method under the condition of non-synchronous sampling are described in this paper.

  11. Volume digital image correlation to assess displacement field in compression loaded bread crumb under X-ray microtomography

    KAUST Repository

    Moussawi, Ali; Xu, Jiangping; Nouri, Hedi; Guessasma, Sofiane; Lubineau, Gilles

    2014-01-01

    are processed using image analysis. A subset-based digital volume correlation method is used to achieve the 3D displacement field. Within the limit of the approach, deterministic search strategy is implemented for solving subset displacement in each deformed

  12. Intraoral radiology in general dental practices - a comparison of digital and film-based X-ray systems with regard to radiation protection and dose reduction.

    Science.gov (United States)

    Anissi, H D; Geibel, M A

    2014-08-01

    The purpose of this study was to gain insight into the distribution and application of digital intraoral radiographic techniques within general dental practices and to compare these with film-based systems in terms of patient dose reduction. 1100 questionnaires were handed out to general dental practitioners. Data was analyzed with respect to the type of system by using descriptive statistics and nonparametric tests, i.e. Kruskal-Wallis, Mann-Whitney and chi-square test (SPSS 20). 64% of the questioned dentists still use film-based radiology, 23% utilize storage phosphor plate (SPP) systems and 13% use a charge-coupled device (CCD). A strong correlation between the number of dentists working in a practice and the use of digital dental imaging was observed. Almost 3/4 of the film users work with E- or F-speed film. 45% of them refuse to change to a digital system. The use of lead aprons was popular, while only a minority preferred thyroid shields and rectangular collimators. A fourfold reduction of exposure time from D-speed film to CCD systems was observed. Due to detector size and positioning errors, users of CCD systems take significantly more single-tooth radiographs in total. Considering the number of radiographs per patient, there is only a slight tendency towards more X-rays with CCD systems. Up to image generation, digital systems seem to be as or even more difficult to handle than film-based systems, while their handling was favored after radiographic exposure. Despite a slight increase of radiographs taken with CCD systems, there is a significant dosage reduction. Corresponding to the decrease in exposure time, the patient dose for SPP systems is reduced to one half compared to film. The main issues in CCD technology are positioning errors and the size of the X-ray detectors which are difficult to eliminate. The usage of radiation protection measures still needs to be improved. ► Responsible use of digital intraoral radiology results in a significant

  13. Application of Oversampling to obtain the MTF of Digital Radiology Equipment.

    Science.gov (United States)

    Narváez, M.; Graffigna, J. P.; Gómez, M. E.; Romo, R.

    2016-04-01

    Within the objectives of theproject Medical Image Processing for QualityAssessment ofX Ray Imaging, the present research work is aimed at developinga phantomX ray image and itsassociated processing algorithms in order to evaluatethe image quality rendered by digital X ray equipment. These tools are used to measure various image parameters, among which spatial resolution shows afundamental property that can be characterized by the Modulation Transfer Function (MTF)of an imaging system [1]. After performing a thorough literature surveyon imaging quality control in digital X film in Argentine and international publications, it was decided to adopt for this work the Norm IEC 62220 1:2003 that recommends using an image edge as a testingmethod. In order to obtain the characterizing MTF, a protocol was designedfor unifying the conditions under which the images are acquired for later evaluation. The protocol implied acquiring a radiography image by means of a specific referential technique, i.e. referred either to voltage, current, time, distance focus plate (/film?) distance, or other referential parameter, and to interpret the image through a system of computed radiology or direct digital radiology. The contribution of the work stems from the fact that, even though the traditional way of evaluating an X film image quality has relied mostly on subjective methods, this work presents an objective evaluative toolfor the images obtained with a givenequipment, followed by a contrastive analysis with the renderings from other X filmimaging sets.Once the images were obtained, specific calculations were carried out. Though there exist some methods based on the subjective evaluation of the quality of image, this work offers an objective evaluation of the equipment under study. Finally, we present the results obtained on different equipment.

  14. Application of Oversampling to obtain the MTF of Digital Radiology Equipment

    International Nuclear Information System (INIS)

    Narváez, M.; Graffigna, J. P.; Gómez, M. E.; Romo, R.

    2016-01-01

    Within the objectives of theproject Medical Image Processing for QualityAssessment ofX Ray Imaging, the present research work is aimed at developinga phantomX ray image and itsassociated processing algorithms in order to evaluatethe image quality rendered by digital X ray equipment. These tools are used to measure various image parameters, among which spatial resolution shows afundamental property that can be characterized by the Modulation Transfer Function (MTF)of an imaging system [1]. After performing a thorough literature surveyon imaging quality control in digital X film in Argentine and international publications, it was decided to adopt for this work the Norm IEC 62220 1:2003 that recommends using an image edge as a testingmethod. In order to obtain the characterizing MTF, a protocol was designedfor unifying the conditions under which the images are acquired for later evaluation. The protocol implied acquiring a radiography image by means of a specific referential technique, i.e. referred either to voltage, current, time, distance focus plate (/film?) distance, or other referential parameter, and to interpret the image through a system of computed radiology or direct digital radiology. The contribution of the work stems from the fact that, even though the traditional way of evaluating an X film image quality has relied mostly on subjective methods, this work presents an objective evaluative toolfor the images obtained with a givenequipment, followed by a contrastive analysis with the renderings from other X filmimaging sets.Once the images were obtained, specific calculations were carried out. Though there exist some methods based on the subjective evaluation of the quality of image, this work offers an objective evaluation of the equipment under study. Finally, we present the results obtained on different equipment. (paper)

  15. X-ray interferometers

    International Nuclear Information System (INIS)

    Franks, A.

    1980-01-01

    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.)

  16. Extremity x-ray

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003461.htm Extremity x-ray To use the sharing features on this page, ... in the body Risks There is low-level radiation exposure. X-rays are monitored and regulated to provide the ...

  17. X-rays utilization

    International Nuclear Information System (INIS)

    Rebigan, F.

    1979-03-01

    The modality of X-ray utilization in different activities and economy is given. One presents firstly quantities and units used in radiation dosimetry and other fields. One gives the generation of X-rays, their properties as well as the elements of radiation protection. The utilization characteristics of these radiations in different fields are finally given. (author)

  18. 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, ... d like to talk with you about chest radiography also known as chest x-rays. Chest x- ...

  19. Intraoral radiology in general dental practices. A comparison of digital and film-based X-ray systems with regard to radiation protection and dose reduction

    Energy Technology Data Exchange (ETDEWEB)

    Anissi, H.D. [Ulm Univ. (Germany). Dentistry; Geibel, M.A. [Ulm Univ. (Germany). Dept. of Dentomaxillofacial Surgery

    2014-08-15

    Purpose: The purpose of this study was to gain insight into the distribution and application of digital intraoral radiographic techniques within general dental practices and to compare these with film-based systems in terms of patient dose reduction. Materials and Methods: 1100 questionnaires were handed out to general dental practitioners. Data was analyzed with respect to the type of system by using descriptive statistics and nonparametric tests, i.e. Kruskal-Wallis, Mann-Whitney and chi-square test (SPSS 20). Results: 64% of the questioned dentists still use film-based radiology, 23% utilize storage phosphor plate (SPP) systems and 13% use a charge-coupled device (CCD). A strong correlation between the number of dentists working in a practice and the use of digital dental imaging was observed. Almost 3/4 of the film users work with E- or F-speed film. 45% of them refuse to change to a digital system. The use of lead aprons was popular, while only a minority preferred thyroid shields and rectangular collimators. A fourfold reduction of exposure time from D-speed film to CCD systems was observed. Due to detector size and positioning errors, users of CCD systems take significantly more single-tooth radiographs in total. Considering the number of radiographs per patient, there is only a slight tendency towards more X-rays with CCD systems. Up to image generation, digital systems seem to be as or even more difficult to handle than film-based systems, while their handling was favored after radiographic exposure. Conclusion: Despite a slight increase of radiographs taken with CCD systems, there is a significant dosage reduction. Corresponding to the decrease in exposure time, the patient dose for SPP systems is reduced to one half compared to film. The main issues in CCD technology are positioning errors and the size of the X-ray detectors which are difficult to eliminate. The usage of radiation protection measures still needs to be improved. (orig.)

  20. Intraoral radiology in general dental practices. A comparison of digital and film-based X-ray systems with regard to radiation protection and dose reduction

    International Nuclear Information System (INIS)

    Anissi, H.D.; Geibel, M.A.

    2014-01-01

    Purpose: The purpose of this study was to gain insight into the distribution and application of digital intraoral radiographic techniques within general dental practices and to compare these with film-based systems in terms of patient dose reduction. Materials and Methods: 1100 questionnaires were handed out to general dental practitioners. Data was analyzed with respect to the type of system by using descriptive statistics and nonparametric tests, i.e. Kruskal-Wallis, Mann-Whitney and chi-square test (SPSS 20). Results: 64% of the questioned dentists still use film-based radiology, 23% utilize storage phosphor plate (SPP) systems and 13% use a charge-coupled device (CCD). A strong correlation between the number of dentists working in a practice and the use of digital dental imaging was observed. Almost 3/4 of the film users work with E- or F-speed film. 45% of them refuse to change to a digital system. The use of lead aprons was popular, while only a minority preferred thyroid shields and rectangular collimators. A fourfold reduction of exposure time from D-speed film to CCD systems was observed. Due to detector size and positioning errors, users of CCD systems take significantly more single-tooth radiographs in total. Considering the number of radiographs per patient, there is only a slight tendency towards more X-rays with CCD systems. Up to image generation, digital systems seem to be as or even more difficult to handle than film-based systems, while their handling was favored after radiographic exposure. Conclusion: Despite a slight increase of radiographs taken with CCD systems, there is a significant dosage reduction. Corresponding to the decrease in exposure time, the patient dose for SPP systems is reduced to one half compared to film. The main issues in CCD technology are positioning errors and the size of the X-ray detectors which are difficult to eliminate. The usage of radiation protection measures still needs to be improved. (orig.)

  1. X-ray tube transformer

    International Nuclear Information System (INIS)

    1980-01-01

    An X-ray generator is described which comprises a transmission line transformer including an electrical conductor with a cavity and a second electrical conductor including helical windings disposed along a longitudinal axis within the cavity of the first conductor. The windings have a pitch which varies per unit length along the axis. There is dielectric material in the cavity for insulation and to couple electromagnetically the two conductors in response to an electric current flowing through the conductors, which have an impedance between them; this varies with distance along the axis of the helix of the second conductor. An X-ray tube is disposed along the longitudinal axis within the cavity, for radiating X-rays. The invention increases the voltage of applied voltage pulses at the remote tube-head with a transformer formed by using a spiral delay line geometry to give a tapered-impedance coaxial high voltage multiplier for pulse voltage operation. This transformer is smaller and lighter than previous designs for the same high peak voltage and power ratings. This is important because the penetration capabilities of Flash X-ray equipment increase with voltage, particularly in heavy materials such as steel. (U.K.)

  2. High precision instrumentation for measuring the true exposure time in diagnostic X-ray examinations

    International Nuclear Information System (INIS)

    Silva, Danubia B.; Santos, Marcus A.P.; Barros, Fabio R.; Santos, Luiz A.P.

    2013-01-01

    One of the most important physical quantities to be evaluated in diagnostic radiology is the radiation exposure time experimented by the patient during the X-ray examination. IAEA and WHO organizations have suggested that any country must create a quality surveillance program to verify if each type of ionizing radiation equipment used in the hospitals and medical clinics are in conformity with the accepted uncertainties following the international standards. The purpose of this work is to present a new high precision methodology for measuring true exposure time in diagnostic X-ray examinations: pulsed, continuous or digital one. An electronic system named CronoX, which will be soon registered at the Brazilian Patent Office (INPI), is the equipment that provides such a high precision measurement. The principle of measurement is based on the electrical signal captured by a sensor that enters in a regeneration amplifier to transform it in a digital signal, which is treated by a microprocessor (uP). The signal treatment results in a two measured times: 1) T rx , the true X-ray exposure time; 2) T nx , the time in which the X-ray machine is repeatedly cut off during the pulsed irradiation and there is no delivery dose to the patient. Conventional Polymat X-ray equipment and dental X-ray machines were used to generate X-ray photons and take the measurements with the electronic systems. The results show that such a high precision instrumentation displays the true exposure time in diagnostic X-ray examinations and indicates a new method to be purposed for the quality surveillance programs in radiology. (author)

  3. Effects on image quality of a 2D antiscatter grid in x-ray digital breast tomosynthesis: Initial experience using the dual modality (x-ray and molecular) breast tomosynthesis scanner

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Tushita, E-mail: tp3rn@virginia.edu [Department of Physics, University of Virginia, Charlottesville, Virginia 22904 (United States); Peppard, Heather [Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia 22908 (United States); Williams, Mark B. [Department of Physics, University of Virginia, Charlottesville, Virginia 22904 (United States); Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia 22908 (United States); Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908 (United States)

    2016-04-15

    Purpose: Radiation scattered from the breast in digital breast tomosynthesis (DBT) causes image degradation, including loss of contrast between cancerous and background tissue. Unlike in 2-dimensional (2D) mammography, an antiscatter grid cannot readily be used in DBT because changing alignment between the tube and detector during the scan would result in unacceptable loss of primary radiation. However, in the dual modality breast tomosynthesis (DMT) scanner, which combines DBT and molecular breast tomosynthesis, the tube and detector rotate around a common axis, thereby maintaining a fixed tube-detector alignment. This C-arm geometry raises the possibility of using a 2D (cellular) focused antiscatter grid. The purpose of this study is to assess change in image quality when using an antiscatter grid in the DBT portion of a DMT scan under conditions of fixed radiation dose. Methods: Two 2D focused prototype grids with 80 cm focal length were tested, one stack-laminated from copper (Cu) and one cast from a tungsten-polymer (W-poly). They were reciprocated using a motion scheme designed to maximize transmission of primary x-ray photons. Grid-in and grid-out scatter-to-primary ratios (SPRs) were measured for rectangular blocks of material simulating 30%, 50%, and 70% glandular tissue compositions. For assessment of changes in image quality through the addition of a grid, the Computerized Imaging Reference Systems, Inc., phantom Model 011A containing a set of 1 cm thick blocks simulating a range of glandular/adipose ratios from 0/100 to 100/0 was used. To simulate 6.5 and 8.5 cm thick compressed breasts, 1 cm thick slices of PMMA were added to the Model 011A phantom. DBT images were obtained with and without the grid, with exposure parameters fixed for a given compressed thickness. Signal-difference-to-noise ratios (SDNRs), contrast, and voxel value-based attenuation coefficients (μ) were measured for all blocks from reconstructed phantom images. Results: For 4, 6, and

  4. Improvement in limit of detection in particle induced X-ray emission by means of rise time and pulse shape discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Papp, Tibor E-mail: tibpapp@netscape.nettibpapp@yahoo.ca; Lakatos, Tamas; Nejedly, Zdenek; Campbell, John L

    2002-04-01

    A digital signal processor, based upon high-rate sampling of the preamplifier output, and equipped with rise time and pulse shape discrimination, has been tested in three situations. This processor provided significant improvement of particle induced X-ray emission and X-ray fluorescence detection limits over the state of the art analog processors, depending on the energy and intensity distribution of the X-ray spectra. Additionally it had a superior performance when measurements were performed in an environment of large electronic noise and in large nuclear background environment. It has also improved the reduction of several artifacts in X-ray spectra.

  5. Phosphor Scanner For Imaging X-Ray Diffraction

    Science.gov (United States)

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

    1992-01-01

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

  6. Three-dimensional cascaded system analysis of a 50 µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis.

    Science.gov (United States)

    Zhao, C; Vassiljev, N; Konstantinidis, A C; Speller, R D; Kanicki, J

    2017-03-07

    High-resolution, low-noise x-ray detectors based on the complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been developed and proposed for digital breast tomosynthesis (DBT). In this study, we evaluated the three-dimensional (3D) imaging performance of a 50 µm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). The two-dimensional (2D) angle-dependent modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) were experimentally characterized and modeled using the cascaded system analysis at oblique incident angles up to 30°. The cascaded system model was extended to the 3D spatial frequency space in combination with the filtered back-projection (FBP) reconstruction method to calculate the 3D and in-plane MTF, NNPS and DQE parameters. The results demonstrate that the beam obliquity blurs the 2D MTF and DQE in the high spatial frequency range. However, this effect can be eliminated after FBP image reconstruction. In addition, impacts of the image acquisition geometry and detector parameters were evaluated using the 3D cascaded system analysis for DBT. The result shows that a wider projection angle range (e.g.  ±30°) improves the low spatial frequency (below 5 mm -1 ) performance of the CMOS APS detector. In addition, to maintain a high spatial resolution for DBT, a focal spot size of smaller than 0.3 mm should be used. Theoretical analysis suggests that a pixelated scintillator in combination with the 50 µm pixel pitch CMOS APS detector could further improve the 3D image resolution. Finally, the 3D imaging performance of the CMOS APS and an indirect amorphous silicon (a-Si:H) thin-film transistor (TFT) passive pixel sensor (PPS) detector was simulated and compared.

  7. Image quality analysis of digital mammographic equipments

    Energy Technology Data Exchange (ETDEWEB)

    Mayo, P.; Pascual, A.; Verdu, G. [Valencia Univ. Politecnica, Chemical and Nuclear Engineering Dept. (Spain); Rodenas, F. [Valencia Univ. Politecnica, Applied Mathematical Dept. (Spain); Campayo, J.M. [Valencia Univ. Hospital Clinico, Servicio de Radiofisica y Proteccion Radiologica (Spain); Villaescusa, J.I. [Hospital Clinico La Fe, Servicio de Proteccion Radiologica, Valencia (Spain)

    2006-07-01

    The image quality assessment of a radiographic phantom image is one of the fundamental points in a complete quality control programme. The good functioning result of all the process must be an image with an appropriate quality to carry out a suitable diagnostic. Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is C.D.M.A.M. 3.4, which facilitates the evaluation of image contrast and detail resolution. One of the most extended indexes to measure the image quality in an objective way is the Image Quality Figure (I.Q.F.). This parameter is useful to calculate the image quality taking into account the contrast and detail resolution of the image analysed. The contrast-detail curve is useful as a measure of the image quality too, because it is a graphical representation in which the hole thickness and diameter are plotted for each contrast-detail combination detected in the radiographic image of the phantom. It is useful for the comparison of the functioning of different radiographic image systems, for phantom images under the same exposition conditions. The aim of this work is to study the image quality of different images contrast-detail phantom C.D.M.A.M. 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments. (authors)

  8. Image quality analysis of digital mammographic equipments

    International Nuclear Information System (INIS)

    Mayo, P.; Pascual, A.; Verdu, G.; Rodenas, F.; Campayo, J.M.; Villaescusa, J.I.

    2006-01-01

    The image quality assessment of a radiographic phantom image is one of the fundamental points in a complete quality control programme. The good functioning result of all the process must be an image with an appropriate quality to carry out a suitable diagnostic. Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is C.D.M.A.M. 3.4, which facilitates the evaluation of image contrast and detail resolution. One of the most extended indexes to measure the image quality in an objective way is the Image Quality Figure (I.Q.F.). This parameter is useful to calculate the image quality taking into account the contrast and detail resolution of the image analysed. The contrast-detail curve is useful as a measure of the image quality too, because it is a graphical representation in which the hole thickness and diameter are plotted for each contrast-detail combination detected in the radiographic image of the phantom. It is useful for the comparison of the functioning of different radiographic image systems, for phantom images under the same exposition conditions. The aim of this work is to study the image quality of different images contrast-detail phantom C.D.M.A.M. 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments. (authors)

  9. WE-DE-207B-08: Towards Standardization of X-Ray Filters in Digital Mammography-Enabled Breast Tomosynthesis Systems

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, S; Vedantham, S; Karellas, A [University of Massachusetts Medical School, Worcester, MA (United States)

    2016-06-15

    Purpose: In digital breast tomosynthesis (DBT) systems capable of digital mammography (DM), Al filters are used during DBT and K-edge filters during DM. The potential for standardizing the x-ray filters with Al, instead of K-edge filters, was investigated with intent to reduce exposure duration and to promote a simpler system design. Methods: Analytical computations of the half-value thickness (HVT) and the photon fluence per mAs (photons/mm2/mAs) for K-edge filters (50µm Rh; 50µm Ag) were compared with Al filters of varying thickness. Two strategies for matching the HVT from K-edge and Al filtered spectra were investigated: varying the kVp for fixed Al thickness, or varying the Al thickness at matched kVp. For both strategies, Al filters were an order of magnitude thicker than K-edge filters. Hence, Monte Carlo simulations were conducted with the GEANT4 toolkit to determine if the scatter-to-primary ratio (SPR) and the point spread function of scatter (scatter PSF) differed between Al and K-edge filters. Results: Results show the potential for replacing currently used Kedge filters with Al. For fixed Al thickness (700µm), ±1 kVp and +(1–3) kVp change, matched HVT of Rh and Ag filtered spectra. At matched kVp, Al thickness range (650,750)µm and (750,860)µm matched the HVT from Rh and Ag filtered spectra. Photon fluence/mAs with Al filters were 1.5–2.5 times higher, depending on kVp and Al thickness, compared to K-edge filters. Although Al thickness was an order higher than K-edge filters, neither the SPR nor the scatter PSF differed from K-edge filters. Conclusion: The use of Al filters for digital mammography is potentially feasible. The increased fluence/mAs with Al could decrease exposure duration for the combined DBT+DM exam and simplify system design. Effect of x-ray spectrum change due to Al filtration on radiation dose, signal, noise, contrast and related metrics are being investigated. Funding support: Supported in part by NIH R21CA176470 and R01

  10. WE-DE-207B-08: Towards Standardization of X-Ray Filters in Digital Mammography-Enabled Breast Tomosynthesis Systems

    International Nuclear Information System (INIS)

    Shrestha, S; Vedantham, S; Karellas, A

    2016-01-01

    Purpose: In digital breast tomosynthesis (DBT) systems capable of digital mammography (DM), Al filters are used during DBT and K-edge filters during DM. The potential for standardizing the x-ray filters with Al, instead of K-edge filters, was investigated with intent to reduce exposure duration and to promote a simpler system design. Methods: Analytical computations of the half-value thickness (HVT) and the photon fluence per mAs (photons/mm2/mAs) for K-edge filters (50µm Rh; 50µm Ag) were compared with Al filters of varying thickness. Two strategies for matching the HVT from K-edge and Al filtered spectra were investigated: varying the kVp for fixed Al thickness, or varying the Al thickness at matched kVp. For both strategies, Al filters were an order of magnitude thicker than K-edge filters. Hence, Monte Carlo simulations were conducted with the GEANT4 toolkit to determine if the scatter-to-primary ratio (SPR) and the point spread function of scatter (scatter PSF) differed between Al and K-edge filters. Results: Results show the potential for replacing currently used Kedge filters with Al. For fixed Al thickness (700µm), ±1 kVp and +(1–3) kVp change, matched HVT of Rh and Ag filtered spectra. At matched kVp, Al thickness range (650,750)µm and (750,860)µm matched the HVT from Rh and Ag filtered spectra. Photon fluence/mAs with Al filters were 1.5–2.5 times higher, depending on kVp and Al thickness, compared to K-edge filters. Although Al thickness was an order higher than K-edge filters, neither the SPR nor the scatter PSF differed from K-edge filters. Conclusion: The use of Al filters for digital mammography is potentially feasible. The increased fluence/mAs with Al could decrease exposure duration for the combined DBT+DM exam and simplify system design. Effect of x-ray spectrum change due to Al filtration on radiation dose, signal, noise, contrast and related metrics are being investigated. Funding support: Supported in part by NIH R21CA176470 and R01

  11. 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.

  12. Combined Synchrotron X-ray Diffraction and Digital Image Correlation Technique for Measurement of Austenite Transformation with Strain in TRIP-assisted Steels

    Energy Technology Data Exchange (ETDEWEB)

    Poling, Whitney A.; Savic, Vesna; Hector, Louis G.; Sachdev, Anil K.; Hu, Xiaohua; Devaraj, Arun; Abu-Farha, Fadi

    2016-04-05

    The strain-induced, diffusionless shear transformation of retained austenite to martensite during straining of transformation induced plasticity (TRIP) assisted steels increases strain hardening and delays necking and fracture leading to exceptional ductility and strength, which are attractive for automotive applications. A novel technique that provides the retained austenite volume fraction variation with strain in TRIP-assisted steels with improved precision is presented. Digital images of the gauge section of tensile specimens were first recorded up to selected plastic strains with a stereo digital image correlation (DIC) system. The austenite volume fraction was measured by synchrotron X-ray diffraction from small squares cut from the gage section. Strain fields in the squares were then computed by localizing the strain measurement to the corresponding region of a given square during DIC post-processing of the images recorded during tensile testing. Results obtained for a QP980 steel are used to study the influence of initial volume fraction of austenite and the austenite transformation with strain on tensile mechanical behavior.

  13. Digital correction of magnification in pelvic x rays for preoperative planning of hip joint replacements: Theoretical development and clinical results of a new protocol

    International Nuclear Information System (INIS)

    The, B.; Diercks, R.L.; Stewart, R.E.; Ooijen, P.M.A. van; Horn, J.R. van

    2005-01-01

    The introduction of digital radiological facilities leads to the necessity of digital preoperative planning, which is an essential part of joint replacement surgery. To avoid errors in the preparation and execution of hip surgery, reliable correction of the magnification of the projected hip is a prerequisite. So far, no validated method exists to accomplish this. We present validated geometrical models of the x-ray projection of spheres, relevant for the calibration procedure to correct for the radiographic magnification. With help of these models a new calibration protocol was developed. The validity and precision of this procedure was determined in clinical practice. Magnification factors could be predicted with a maximal margin of error of 1.5%. The new calibration protocol is valid and reliable. The clinical tests revealed that correction of magnification has a 95% margin of error of -3% to +3%. Future research might clarify if a strict calibration protocol, as presented in this study, results in more accurate preoperative planning of hip joint replacements

  14. 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

  15. X-ray detector

    International Nuclear Information System (INIS)

    Whetten, N.R.; Houston, J.M.

    1977-01-01

    An ionization chamber for use in determining the spatial distribution of x-ray photons in tomography systems comprises a plurality of substantially parallel, planar anodes separated by parallel, planar cathodes and enclosed in a gas of high atomic weight at a pressure from approximately 10 atmospheres to approximately 50 atmospheres. The cathode and anode structures comprise metals which are substantially opaque to x-ray radiation and thereby tend to reduce the resolution limiting effects of x-ray fluoresence in the gas. In another embodiment of the invention the anodes comprise parallel conductive bars disposed between two planar cathodes. Guard rings eliminate surface leakage currents between adjacent electrodes. 8 figures

  16. X-ray apparatus

    International Nuclear Information System (INIS)

    Grady, J.K.

    1985-01-01

    X-ray apparatus is described which has a shutter between the X-ray source and the patient. The shutter controls the level of radiation to which the patient is exposed instead of merely discontinuing the electric power supplied to the source. When the shutter is opened a radiation sensor senses the level of X-radiation. When a preset quantity of X-radiation has been measured an exposure control closes the shutter. Instead of using the radiation sensor, the integrated power supplied to the anode of the X-ray source may be measured. (author)

  17. 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 ...

  18. 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 ...

  19. X-ray examination apparatus

    NARCIS (Netherlands)

    2000-01-01

    The invention relates to an X-ray apparatus which includes an adjustable X-ray filter. In order to adjust an intensity profile of the X-ray beam, an X-ray absorbing liquid is transported to filter elements of the X-ray filter. Such transport is susceptible to gravitational forces which lead to an

  20. Bone X-Ray (Radiography)

    Medline Plus

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

  1. Bone X-Ray (Radiography)

    Science.gov (United States)

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

  2. Bone X-Ray (Radiography)

    Medline Plus

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

  3. Abdomen X-Ray (Radiography)

    Science.gov (United States)

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

  4. X-ray beam qualities for dental radiology purposes

    International Nuclear Information System (INIS)

    Santos, Marcus Aurelio P. dos; Fragoso, Maria da Conceicao de F.; Lima, Ricardo de A.; Hazim, Clovis A.

    2009-01-01

    In order to establish characteristics or properties of equipment for diagnostic radiology, e.g. ion chambers and semiconductor detectors, calibration laboratories offer a set of well-defined radiation conditions, called X-ray qualities, which can be used for many Physics studies and medical purposes. The standardization of radiation qualities has been carried out in several fields of study, but little attention has been given to the area of dental radiology, mainly for medical and physical applications using single-phase units with half-wave rectification. For this reason, a single-phase dental unit with adjustable peak voltage and tube current, called 'variable potential X-ray equipment', was developed aiming to define X-ray beam qualities for test and calibrations purposes. X-ray spectra at 50, 60 and 70 kVp were determined by using a CdTe detector and compared with those obtained for ten commercial X-ray dental units. As a result of this study, a set of X-ray qualities for the variable potential X-ray equipment was determined. The X-ray qualities spectra were utilized as reference for determination of a new set of X-ray qualities characterized for a constant potential X-ray equipment. Thus, sets of X-ray qualities were standardized and implemented in two X-ray laboratories: one with the variable potential X-ray equipment and other with constant potential X-ray equipment. These reference X-ray beam qualities should be used for test and calibration purposes involving scientific studies and services. (author)

  5. Effect of two X-ray tube voltages on detection of approximal caries in digital radiographs. An in vitro study.

    Science.gov (United States)

    Hellén-Halme, Kristina

    2011-04-01

    This study evaluated the effect of two different tube voltages on clinicians' ability to diagnose approximal carious lesions in digital radiographs. One hundred extracted teeth were radiographed twice at two voltage settings, 60 and 70 kV, using a standardized procedure. Seven observers evaluated the radiographs on a standard color monitor pre-calibrated according to DICOM part 14. Evaluations were made at ambient light levels below 50 lx. All observations were analyzed with receiver operating characteristic curves. A histological examination of the teeth served as the criterion standard. A paired t test compared the effects of the two voltages. The significance level was set to p < 0.05. Weighted kappa statistics estimated intra-observer agreement. No significant difference in accuracy of approximal carious lesion diagnosis was found between the two voltage settings. But five observers rated dentin lesions on radiographs exposed at 70 kV better than on radiographs exposed at 60 kV. Intra-observer agreement differed from fair to moderate. There was no significant difference in accuracy of approximal carious lesion diagnosis between digital radiographs exposed with 60 or 70 kV.

  6. Analysis the prospects of use of mobile X-ray diagnostic apparatus of the C-arm type

    International Nuclear Information System (INIS)

    Blinov, N.N.; Mazurov, A.I.

    2000-01-01

    The efficiency of using the mobile X-ray apparatus with the C-arm multi-positional support, equipped with a medium-frequency generator and roentgen image amplifier with a digital channel, and device for obtaining hard copies in the diagnostic, surgical and therapeutic practice, is shown and the basis requirements, imposed in various areas on the apparatus of this type (traumatology, orthopedics, hospital wards studies, X-ray endoscopy, X-ray operational units, intervention roentgenology, angiography), are formulated. The technical characteristics are presented and the operation of the national surgical mobile apparatus RTS-612 is described. The experience in the apparatus operation showed, that x-ray surgical complexes, meeting the requirements of the modern public health in the area of traumatology, orthopedics, cardiosurgery, endoscopy, urology and other areas, wherein the X-ray control during the operation is accomplished, may be created on its basis [ru

  7. Characterization of a team biplane digital x-ray in the pediatric cardiology department; Caracterizacion de un equipo biplano de rayos x digital en el servicio de cardiologia pediatrica

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez Marquez, J.; Huertas Martinez, C.; Corredora Silva, E.; Vano Carruana, E.; Luquero LLopis, N.; Huerga Cabrerizo, C.; Plaza Aparicio, R.; Tellez-Cepeda Ruiz, M.

    2011-07-01

    In cardiology, new digital technologies, are replacing fluoroscopy with image intensifier and television systems. There has been a characterization of the equipment prior to commissioning for clinical use.

  8. Chest X-Ray

    Medline Plus

    Full Text Available ... Disorders Video: The Basketball Game: An MRI Story Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Chest X-ray Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey ...

  9. Chest X-Ray

    Medline Plus

    Full Text Available ... also be useful to help diagnose and monitor treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  10. X-ray tubes

    International Nuclear Information System (INIS)

    Young, R.W.

    1979-01-01

    A form of x-ray tube is described which provides satisfactory focussing of the electron beam when the beam extends for several feet from gun to target. Such a tube can be used for computerised tomographic scanning. (UK)

  11. Chest X-Ray

    Medline Plus

    Full Text Available ... breath, persistent cough, fever, chest pain or injury. It may also be useful to help diagnose and ... have some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to ...

  12. Chest X-Ray

    Medline Plus

    Full Text Available ... An MRI Story Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Chest X-ray ... posted: How to Obtain and Share Your Medical Images Movement Disorders Video: The Basketball Game: An MRI ...

  13. Chest X-Ray

    Medline Plus

    Full Text Available ... accurate diagnosis far outweighs any risk. For more information about chest x-rays, visit Radiology Info dot ... Inc. (RSNA). To help ensure current and accurate information, we do not permit copying but encourage linking ...

  14. Chest X-Ray

    Medline Plus

    Full Text Available ... Site Index A-Z Spotlight Recently posted: Pancreatic Cancer The Limitations of Online Dose Calculators Video: The ... of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  15. Chest X-Ray

    Medline Plus

    Full Text Available ... exams and use a very small dose of ionizing radiation to produce pictures of the inside of the ... chest x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs ...

  16. 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. ...

  17. Chest X-Ray

    Medline Plus

    Full Text Available ... June is Men's Health Month Recently posted: Pancreatic Cancer The Limitations of Online Dose Calculators Video: The ... of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of knee x-rays. A portable x-ray machine is a compact apparatus that can be taken ... of the body being examined, an x-ray machine produces a small burst of radiation that passes ...

  19. Bone X-Ray (Radiography)

    Medline Plus

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

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... ray examination. X-rays usually have no side effects in the typical diagnostic range for this exam. ... x-rays. A Word About Minimizing Radiation Exposure Special care is taken during x-ray examinations to ...